Pubmed abstracts for Protein-Protein Interaction search result :

Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.57926306
The altered phosphatase specificity upon association of eIF 2 with eIF 2B also affects the access of protein kinases to these phosphorylation sites . 0.57926306^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.5353903
In addition , the association of eIF 2B with intact eIF 2 , but not with eIF 2 ( alpha gamma ) , reduces by two fold the rate and extent of removal of 32P by alkaline phosphatase from CK 2 phosphorylated 82 kDa subunit . . 0.5353903^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.69700578
The ability of WG 10 eIF 2 to exchange guanine nucleotides independent of an eIF2B like protein and the inability of phosphorylated WG 10 eIF 2 to interact with reticulocyte eIF2B suggests that WG 10 eIF 2 is different from mammalian eIF 2 and these differences may have occurred in evolution probably due to some changes in the amino acid sequences around the phosphorylation site in eIF2alpha . . 0.69700578^^^ Unlike reticulocyte eIF 2 ( alphaP ) , phosphorylated WG 10 eIF 2 is unable to interact with reticulocyte eIF2B to form a 15S complex . 0.67408763^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Phosphorylation of eIF 2alpha is almost completely inhibited by 20 35 muM hemin , whereas phosphorylation of eIF 2beta is only partially inhibited . ^^^ The protein kinase activity that modifies eIF 2alpha has been shown to have inhibitory activity in the cell free protein synthesizing system , whereas the protein kinase for eIF 2beta has no effect . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
The inhibition of eIF 2B activity was associated with a 2 . 4 fold increase in the proportion of the alpha subunit of eIF 2 in the phosphorylated form . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
One way in which eIF 2 activity could be decreased in tissue extracts would be through a decrease in the activity of the GDP exchange factor , eIF 2B . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
DNA sequence analysis of these alleles and of eIF 2 beta suppressor alleles isolated from haploid strains , identified point mutations that altered one of six amino acids that map to a Cys X 2 Cys X 19 Cys X 2 Cys `` zinc finger ' ' motif and immediately adjacent residues . ^^^ Five of the affected amino acids are identical in the human and yeast eIF 2 beta protein . ^^^ Together with earlier studies ( Donahue et al . , 1988 ) , these point mutations implicate the zinc finger domain of eIF 2 beta in start site selection during the scanning process . ^^^ Our studies indicate that the cysteine residues and the intervening amino acids of this motif are essential for eIF 2 beta function in translation initiation in vivo . ^^^ However , the effects observed in cells containing a copy of eIF 2 beta with a deletion of this motif suggest that this mutated form is still able to associate with other components of the initiation complex , imparting defects on translation initiation . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
With continued exposure to A 23187 ( 3 h ) rates of amino acid incorporation partially recovered , eIF 2 alpha became dephosphorylated , and the inhibition of eIF 2B activity was abolished . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
A comparison of two lysate preparations , which had a 2 fold difference in their protein synthesis rates , indicated that the slower translational rate of the one lysate could be accounted for by its low level of constitutive eIF 2 alpha phosphorylation , with its accompanying decrease in the eIF 2B activity and lower level of polyribosome loading . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
GDP can participate in an eIF 2B catalyzed GDP / GTP exchange reaction to reform the Met tRNA ( f ) . eIF 2 . ^^^ In contrast , when 60 S ribosomal subunits were preincubated with either free eIF 2 or with eIF 2 . eIF 2B complex and then added to a reaction containing both the 40 S initiation complex and eIF 5 , the eIF 2 . ^^^ Under similar experimental conditions , preincubation of 60 S ribosomal subunits with purified eIF 2B ( free of eIF 2 ) failed to cause release of eIF 2 . ^^^ GDP does not act as a direct substrate for eIF 2B mediated release of eIF 2 from ribosomes . ^^^ Rather , the affinity of 60 S ribosomal subunits for either eIF 2 , or the eIF 2 moiety of the eIF 2 . eIF 2B complex , prevents association of 60 S ribosomal subunits with eIF 2 . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
This inhibition is relieved upon addition of ATP , showing that Cibacron blue 3G A competes with ATP for eIF 2 . eIF 2 beta subunit , active in binding of mRNA , is recovered upon chromatography of eIF 2 in denaturing conditions over matrix bound Cibacron blue 3G A . ^^^ During initiation of protein synthesis , the eIF 2 beta subunit may thus interact with three ligands important for translational control : Met tRNA ( f ) , mRNA and ATP . . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Close values of dissociation constants for WGeIF 2 complexes with guanine nucleotides suggest that at a sufficiently high [ GTP ] / [ GDP ] ratio the nucleotide exchange in wheat cells may take place without the participation of specific factor ( eIF 2B ) which catalyzes the nucleotide exchange on eIF 2 from mammalian cells . . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
None of the sua genes is allelic to SUI 2 or sui 3 , which encode eIF 2 alpha and eIF 2 beta , respectively , or to SUI 1 . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
One of the factors involved in the postfertilization activation of protein synthesis in the sea urchin , Strongylocentrotus purpuratus , is the activation of eIF 2B , the initiation factor responsible for guanine nucleotide exchange on eIF 2 . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
We have found that purified eIF 2B dissociates eIF 2 . [ 3H ] GDP as efficiently in the presence of GTP as it does in the presence of GDP provided Met tRNA ( fMet ) is added . tRNA ( fMet ) is ineffective , and there is no Met tRNA ( fMet ) requirement for exchange with GDP . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
The influence of changing concentrations of GDP , methionyl tRNAi , eIF 2 and eIF 2B on possible rates of initiation of protein synthesis have been explored in calculations based on previously derived rate constants for interaction of the components involved in formation of ternary or quaternary complexes of eIF 2B , eIF 2 , GTP and Met tRNAi . ^^^ Biochem . 175 , 93 : 1988 ) of higher concentrations of eIF 2 and eIF 2B in cells than hitherto proposed become necessary to support known rates of initiation . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Int . 22 , 523 533 : 1990 ) for the reactions catalysed by eIF 2B ( GEF ) in which free GDP exchanges with GDP bound to eIF 2 have been re evaluated using the computational procedures developed by Chau et al . ( J . ^^^ GDP ( eIF 2B . eIF 2 . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
In other systems eIF 2B activity is regulated by phosphorylation of the alpha subunit of a second initiation factor , eIF 2 . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
When physiological substrates for casein kinase 2 are examined , glycogen synthase and eukaryotic initiation factor 3 ( eIF 3 ) ( p 120 ) are phosphorylated by the alpha subunit at a rate equivalent to that of the holoenzyme , while phosphorylation of eIF 3 ( p 67 ) is reduced 9 fold and eIF 2 beta is not modified . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
We have now applied the same method in combination with CNBr cleavage and microsequence analysis in order investigate which part of the polypeptide chain of eIF 2 beta is in close contact to the bound GTP . ^^^ From the three main CNBr fragments of eIF 2 beta , the C terminal one was found to be labelled by the applied GTP photoaffinity analogue , Guo ( 2 ' , 3 ' TDBH ) ppp . ^^^ Because the cDNA sequence of the gamma subunit of eIF 2 has not yet been published and because cDNA sequence analysis of eIF 2 beta revealed only two out of three consensus sequence elements of a GTP binding domain , we also sequenced the CNBr fragments of eIF 2 gamma . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Furthermore , the inhibition was associated with a 7 . 5 fold increase in the proportion of the alpha subunit of eukaryotic initiation factor 2 ( eIF 2 ) present in the phosphorylated form and a reduction in the activity of eukaryotic initiation factor 2B ( eIF 2B ) to 37 % of the control value . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
GDP ) to act as a competitive inhibitor of eIF 2B catalysed exchange of eIF 2 bound GDP has been investigated by modelling data provided by Rowlands et al . ( J . ^^^ GDP without substantial increase in its affinity for eIF 2B over that of eIF 2 . ^^^ Classic double reciprocal plots for competitive inhibition were found only when [ eIF 2B ] was low in relation to [ eIF 2 ( alpha P ) . ^^^ Relatively high cellular [ eIF 2B ] lessens the inhibitory effect of eIF 2 ( alpha P ) . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Stimulation of translation correlates with enhanced phosphorylation of eIF 4F , eIF 4B , eIF 2B , eIF 3 and ribosomal protein S 6 , whereas inhibition correlates with phosphorylation of eEF 2 and the alpha subunit of eIF 2 . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
There were no reproducible , significant changes in eIF 4A , eIF 4B , or eIF 2 beta in cells infected by any of these viruses . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
The inhibition of eIF 2B activity was associated with an increase in the proportion of the alpha subunit of eIF 2 in the phosphorylated form from 9 . 6 % in control livers to 30 . 7 % in livers perfused with medium containing vasopressin . ^^^ The results demonstrate the novel finding that the inhibition of protein synthesis in vasopressin treated livers is caused by a reduction in eIF 2B activity due to an increase in phosphorylation of eIF 2 alpha . . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Published data have been analysed to determine the rate constants governing the exchange of GDP in the complex of the eukaryotic protein synthesis initiation factor eIF 2 with GDP , catalysed by eIF 2B . ^^^ The interaction of eIF 2B with eIF 2 . ^^^ Assuming a substituted enzyme mechanism that leads to displacement of GDP and ultimately to formation of a quaternary complex eIF 2B . eIF 2 . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Quaternary complexes were fixed with glutaraldehyde and reacted with affinity purified polyclonal antibodies against eIF 2 alpha , eIF 2 beta or eIF 2 gamma . ^^^ Within this region , eIF 2 alpha points to the rear side , whereas eIF 2 beta and eIF 2 gamma point to the frontal side of the 40S subunit indicating an elongated shape of eIF 2 about 15 nm long . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
The former is likely a result of the latter , since we find that reticulocyte lysate has about twice the eIF 2B necessary to recycle the eIF 2 . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
GDP complex , and another initiation factor termed eIF 2B is necessary to recycle eIF 2 by displacing GDP by GTP . ^^^ In rabbit reticulocytes , inhibition of protein synthesis is accompanied by the phosphorylation of the alpha subunit of eIF 2 , a process that does not render eIF 2 inactive , but prevents it from being recycled by eIF 2B . ^^^ Furthermore , the possible impact of the eIF 2 / eIF 2B ratio and of the subcellular compartmentation of these factors ( and the eIF 2 alpha kinases ) on mammalian protein synthesis is discussed . . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Although there is a low level of phosphorylation of eIF 2 alpha in gel filtered lysate given hemin but no glucose 6 phosphate , it can not account for the loss of eIF 2B activity , since this phosphorylation is removed by antibody to the hemin controlled translational repressor or isocitrate , which do not restore protein synthesis or eIF 2B activity , and not by fructose 1 , 6 diphosphate , which does partially restore protein synthesis and eIF 2B activity . ^^^ Additional support for this conclusion is our finding that protein synthesis and eIF 2B activity in partially hemin deficient lysate can be restored by high levels of glucose 6 phosphate or fructose 1 , 6 diphosphate without a reduction in the level of phosphorylated eIF 2 alpha , suggesting that such levels of sugar phosphate may permit restoration of normal function with a limiting amount of eIF 2B . . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
The ICF activity appeared to copurify with a complex of initiation factors eIF 2 and eIF 2B . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
First , the mutant ' s translational defect can be relieved by addition of eIF 2 or eIF 2B ( GTP recycling factor ) . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
As for the restorative effect of cAMP and GTP , it was observed that c ) these compounds restored the globin synthesis and the binding of [ 35S ] Met tRNAf to the 40S ribosomal subunits , and promoted the dephosphorylation of eIF 2 ( alpha P ) , d ) the rates of the restored synthesis of globin were lower than the control , and e ) cAMP promoted the release of [ 3H ] GDP from the eIF 2 ( alpha P ) 10 [ 3H ] GDP complex and the formation of eIF 2 ( alpha P ) 10 eIF 2B complex . ^^^ That is , cAMP inhibited the phosphorylation of eIF 2 alpha and promoted both the release of GDP from eIF 2 and the formation of eIF 2 ( alpha P ) 10 eIF 2B complex , and GTP prevented both the activation of HCI and the phosphorylation of eIF 2 alpha . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
The 1416 bp cDNA encodes a protein of 333 amino acids ( 38 , 404 daltons ) with characteristics that resemble authentic purified eIF 2 beta . ^^^ De novo synthesized eIF 2 beta from cDNA transcripts incorporates into endogenous rabbit eIF 2 complexes . ^^^ The polylysine blocks and the zinc finger motif suggest that eIF 2 beta interacts with RNA . ^^^ A yeast protein , Sui 3 , isolated as an extragenic suppressor of his 4 initiation codon mutations , exhibits extensive sequence identity with human eIF 2 beta , especially in the polylysine and zinc finger domains , thereby reinforcing the view that these elements are important for function . . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Mutations at a Zn ( 2 ) finger motif in the yeast eIF 2 beta gene alter ribosomal start site selection during the scanning process . ^^^ This motif is present in a cDNA sequence encoding the human eIF 2 beta gene product . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
These two forms of eIF 2 beta polypeptides are also detected in reticulocyte lysates when the proteins are resolved by two dimensional isoelectric focusing dodecyl sulfate polyacrylamide gel electrophoresis followed by immunoblotting . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Met tRNAf ] as well as in the eIF 2 . eIF 2B complex the alpha subunit of eIF 2 was found to be specifically labeled . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Phosphorylation by these kinases is additive , suggesting that they phosphorylate different sites ( serine residues ) in eIF 2 beta . ^^^ Two dimensional peptide mapping of the phosphopeptides generated from labelled eIF 2 beta by digestion with trypsin , cyanogen bromide or Staphylococcus aureus V 8 proteinase showed that protein kinase C and casein kinase 2 phosphorylated distinct and different sites in this protein . ^^^ Analysis of the phosphopeptides derived from eIF 2 beta labelled by both kinases together strongly suggested that the sites labelled by protein kinase C and casein kinase 2 are adjacent in the primary sequence . ^^^ Rat liver eIF 2 beta was also found to be a substrate for protein kinase C and casein kinase 2 , which were again shown to label different serine residues . . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Kinetic constants in the functioning of eIF 2 and eIF 2B . ^^^ Minimum rate constants for reactions catalysed by the eukaryotic initiation factor eIF 2B in promoting formation of the ternary complex eIF 2 . ^^^ The most plausible sequence of reactions in vivo is when eIF 2B remains bound to eIF 2 . ^^^ Rate constants for reaction of eIF 2B and eIF 2 . ^^^ This finding suggests some form of sequestration of eIF 2 and eIF 2B in the cell to facilitate interaction , which may result in only a portion of cellular eIF 2 being actively engaged in initiation . . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
These data show that the DEAE 100 inhibitor ( s ) contains a nuclease while the DEAE 350 inhibitor ( s ) is associated with eIF 2 alpha and eIF 2 beta protein kinases . . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Evidence that phosphorylation of eIF 2 ( alpha ) prevents the eIF 2B mediated dissociation of eIF 2 10 GDP from the 60 S subunit of complete initiation complexes . ^^^ Recent observations have indicated that eukaryotic initiation factor ( eIF ) 2 and GTP or GDP normally bind to 60 S ribosomal subunits in rabbit reticulocyte lysate and that when eIF 2 alpha is phosphorylated and polypeptide chain initiation is inhibited , eIF 2 10 GDP accumulates on 60 S subunits due to impaired dissociation that is normally mediated by the reversing factor ( eIF 2B ) . ^^^ These results suggest that eIF 2B must normally promote dissociation of eIF 2 10 GDP from the 60 S subunit of complete initiation complexes before they can elongate but can not when eIF 2 alpha is phosphorylated , resulting in the accumulation of these complexes , some of which dissociate into Met tRNA ( f ) 10 40 S 10 mRNA and 60 S 10 eIF 2 10 GDP . . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Available data for the formation of the ternary complex eIF 2 10 GTP 10 methionyl tRNAi involved in eukaryotic initiation and of the inhibition of ternary complex formation by GDP have been examined with a view to determining the mechanism by which eIF 2B facilitates nucleotide exchange . ^^^ Two mechanisms have been considered first a displacement reaction in which eIF 2B displaces GDP and GTP in a manner analogous to a `` ping pong ' ' enzyme mechanism , and secondly the possibility that binding of eIF 2B to eIF 2 nucleotide complexes enhances the rate of nucleotide exchange without itself inducing nucleotide displacement . ^^^ Comparison has been made between the properties of eIF 2 and eIF 2B and of the bacterial elongation factors Tu and Ts . ^^^ This phosphorylation appears to change the equilibria in the reaction mechanism such that the transferred entity ( eIF 2 ) becomes firmly bound to the catalyst ( eIF 2B ) . ^^^ Minimum rate constants for the formation of eIF 2 10 eIF 2B from eIF 2 10 GDP and eIF 2 10 GTP and reverse reactions are derived . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
One of these contained all three components ( eIF 2 alpha , eIF 2 beta , eIF 2 gamma ) characteristic of mammalian eIF 2 , whilst the other fraction contained only two . ^^^ The absence of eIF 2 beta from this fraction was not due to its proteolytic degradation during purification since it was unaffected by the inclusion of a range of proteinase inhibitors in the isolation media . ^^^ The properties of eIF 2 containing or lacking eIF 2 beta have been directly compared . ^^^ It was found that eIF 2 beta was not required for the binding of guanine nucleotides to eIF 2 or for formation of ternary initiation complexes with GTP and the initiator tRNA . eIF 2 lacking eIF 2 beta was able to form 40 S initiation complexes and the presence of eIF 2 beta was also unnecessary for the stimulation of eIF 2 activity by the recycling factor , eIF 2B . ^^^ Some of these findings are at variance with previous reports in which eIF 2 beta was removed proteolytically . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Adenoviral mRNA translation was restored to the extract from the doubly infected cells by the addition of the guanine nucleotide exchange factor eIF 2B , which is responsible for the normal recycling of eIF 2 during protein synthesis . ^^^ This indicates that the residual kinase in the doubly infected cells leads to a limitation in functional ( nonsequestered ) eIF 2B and hence functional ( GTP containing ) eIF 2 and that under these conditions influenza viral mRNAs are selectively translated over adenoviral mRNAs . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
In contrast , the beta subunits of the liver and reticulocyte factors were distinct ; they had different molecular weights , and antibodies against rat liver eIF 2 beta did not recognize the beta subunit of the reticulocyte factor . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Evaluation and significance of kinetic parameters governing function of protein synthesis initiation factors eIF 2 and eIF 2B . ^^^ Published data dealing with the formation of the ternary complex eIF 2 10 GTP 10 met tRNAi involved in eukaryotic initiation have been evaluated to calculate the expected inhibition by GDP and the role of eIF 2B in limiting this inhibition . ^^^ However , derivation of ' on ' and ' off ' rates for the interaction of GTP and GDP with eIF 2 demonstrates that these are too slow in the absence of eIF 2B to support active protein synthesis , particularly if eIF 2 is released from ribosomes as eIF 2 10 GDP . ^^^ Phosphorylation of the alpha subunit of eIF 2 appears to affect only those parameters influenced by eIF 2B . ^^^ Consideration of the kinetic parameters favours the formation of a ternary complex of eIF 2 10 eIF 2B 10 GDP en route to eIF 2 10 GTP as opposed to displacement of GDP from eIF 2 10 GDP by eIF 2B . . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Eukaryotic initiation factor ( eIF ) 2 alpha , eIF 2 beta , and eIF 4A each formed a single immunoreactive spot ; eIF 2 gamma formed 2 spots ; and eIF 4B formed a complex array of 12 20 spots . ^^^ After 4 days of growth in unreplenished medium , when translation rates have dropped 4 6 fold , several alterations in the isoelectric forms were observed : eIF 2 alpha now occurred in 2 forms , eIF 2 beta was present in 3 4 forms , and the most acidic cluster of eIF 4B variants was decreased or absent while a new isoelectric variant appeared at the basic end of the array . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
It is free of eIF 2 , but possesses eIF 2B activity . ^^^ Its purification properties suggest that it is distinct from previously characterized initiation factors , including eIF 2 / eIF 2B complex , and its possible relationship to known initiation factors is discussed . . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
On the basis of immunoblotting techniques , eIF 4A is highly conserved , eIF 2 alpha , eIF 3 , and eIF 4B are somewhat less conserved , and eIF 2 beta is the least conserved of the proteins examined . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Immunoblot analyses show that eIF 2 alpha and eIF 2 beta become modified during heat shock , and eIF 4B variants disappear . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Translation of exogenous mRNAs in micrococcal nuclease treated extracts from Ehrlich ascites tumor cells is greatly stimulated by the addition of crude initiation factors or initiation factors eIF 2B and eIF 2 containing eIF 2B . ^^^ The requirement for exogenous eIF 2B in micrococcal nuclease treated extracts does not result from either loss or enhanced phosphorylation of eIF 2 during incubation . . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Spots identified as eukaryotic initiation factor ( eIF ) 2 alpha , eIF 2 beta , eIF 2 gamma , eIF 4A , and four eIF 3 proteins of less than 50 , 000 Da corresponded to moderately abundant lysate proteins . ^^^ Minor isoelectric variant forms of eIF 2 beta , eIF 2 gamma , and eIF 4A were detected by immunoblot analysis of lysate proteins , suggesting either covalent modification of these factor proteins or contaminating antibodies . eIF 2 beta and eIF 4B were present in at least two isoelectric forms , confirming covalent modification of these proteins . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Cross linking of Met tRNAf to eIF 2 beta and to the ribosomal proteins S3a and S 6 within the eukaryotic inhibition complex , eIF 2 . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Eukaryotic initiation factor 2B ( eIF 2B ) is a heteropentameric guanine nucleotide exchange factor involved in the recycling of eIF 2 during the translation initiation phase of protein synthesis . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
The gene encoding eIF 2 beta in S . cerevisiae maps to chromosome 16 . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
The latter result indicates that the gamma subunit of eIF 2 participates in recognition of the start site for protein synthesis , a role previously demonstrated in yeast for eIF 2 alpha and eIF 2 beta . . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Protein synthesis in the developing rat liver : participation of initiation factors eIF 2 and eIF 2B . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
The eIF 2B epsilon monoclonal antibodies and monoclonal antibodies to the alpha subunit of eIF 2 were then used to directly quantitate the amounts of eIF 2B and eIF 2 in rat liver and rat reticulocytes . ^^^ The ratio of eIF 2B to eIF 2 was found to be approx . 0 . 6 and 0 . 3 in liver and reticulocytes , respectively , supporting the proposition that phosphorylation of only part of the total cellular eIF 2 could potentially sequester all of the eIF 2B into an inactive eIF 2 . eIF 2B complex . ^^^ Overall , the studies presented here are the first to show a direct quantitation of eIF 2 and eIF 2B in different tissues . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Because translation of GCN 4 mRNA is so tightly coupled to eIF 2 activity , genetic analysis of this system has provided unexpected insights into the regulation of eIF 2 and its guanine nucleotide exchange factor , eIF 2B . . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Is there a need for channelling in the functioning of the protein synthesis initiation factors eIF 2 and eIF 2B . ^^^ Calculations suggest that despite the very high association rate constant found for the interaction of eIF 2 and eIF 2B under in vitro conditions , it is unlikely that rates in vivo can be high enough to permit measured rates of protein synthesis . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
This is associated with increased phosphorylation of the alpha subunit of the initiation factor eIF 2 , which in turn impairs the activity of the guanine nucleotide exchange factor , eIF 2B . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
In liver treated with calcium mobilizing hormones , the reduction in eIF 2B activity is the result of an increase in the phosphorylation state of the alpha subunit of a second initiation factor , eIF 2 . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Eukaryotic initiation factor eIF 2B catalyses the exchange of guanine nucleotides on another translation initiation factor , eIF 2 , which itself mediates the binding of the initiator Met tRNA to the 40S ribosomal subunit during translation initiation . eIF 2B promotes the release of GDP from inactive [ eIF 2 . ^^^ Phosphorylation of eIF 2 alpha leads to inhibition of eIF 2B . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
These observed effects may be specific to hsp 70 ( R ) , since they are not observed with rabbit reticulocyte eIF 2 or eIF 2B , and since the comparable hsp 70 from bovine brain is incapable of maintaining or restoring protein synthesis in hemin deficient lysate . . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
These results provide evidence that translational regulation by phosphorylation of eIF 2 alpha and sequestration of eIF 2B can operate in insect cells . . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Increased phosphorylation of eIF 2 alpha ( 5 fold ) and inhibition of eIF 2B activity ( 50 % ) occur in intact GH 3 cells exposed to these agents for 15 min ( Prostko et al . ^^^ Prolonged inhibition of protein synthesis to deplete the ER of substrates for protein processing resulted in increased eIF 2 alpha phosphorylation , decreased eIF 2B activity , and reduced monosome content that were indicative of time dependent blockade ; these inhibitors did not abolish polysomal content . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Expression of mutant eukaryotic initiation factor 2 alpha subunit ( eIF 2 alpha ) reduces inhibition of guanine nucleotide exchange activity of eIF 2B mediated by eIF 2 alpha phosphorylation . ^^^ The inhibition of protein synthesis that occurs upon phosphorylation of the alpha subunit of eukaryotic initiation factor 2 ( eIF 2 alpha ) at serine 51 correlates with reduced guanine nucleotide exchange activity of eIF 2B in vivo and inhibition of eIF 2B activity in vitro , although it is not known if phosphorylation is the cause of the reduced eIF 2B activity in vivo . ^^^ To characterize the importance of eIF 2 alpha phosphorylation in the regulation of eIF 2B activity , we studied the overexpression of mutant eIF 2 alpha subunits in which serine 48 or 51 was replaced by an alanine ( 48A or 51A mutant ) . ^^^ In this study , we show that eIF 2B activity was inhibited in parental CHO cell extracts upon addition of purified reticulocyte heme regulated inhibitor ( HRI ) , an eIF 2 alpha kinase that phosphorylates Ser 51 . ^^^ Preincubation with purified HRI also reduced the eIF 2B activity in extracts from cells overexpressing wild type eIF 2 alpha . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Here we identify the sites at which eIF 2 beta is phosphorylated in vitro by three well characterised protein kinases , casein kinase 2 ( which phosphorylates serine residues 2 and 67 ) , protein kinase C ( serine 13 ) and cAMP dependent protein kinase ( serine 218 ) . ^^^ This constitutes an essential prerequisite for studying the phosphorylation of eIF 2 beta in vivo . ^^^ The major kinase activity against eIF 2 beta in reticulocyte lysates appears in CK 2 and protein phosphatase 2A is the principal enzyme responsible for dephosphorylation of eIF 2 beta phosphorylated by this kinase . . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Consistent with this , prior treatment of eIF 2 with MKu impaired the exchange of bound GDP for GTP which is catalysed by the exchange factor eIF 2B . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Phosphorylation of eIF 2 alpha inhibits initiation in mammalian cells by sequestering eIF 2B , the factor required for exchange of GTP for GDP on eIF 2 . ^^^ These results provide further in vivo evidence that phosphorylation of eIF 2 alpha inhibits translation by impairing eIF 2B function and identify GCN 3 as a regulatory subunit of eIF 2B . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
We propose that these mutations alter the interaction between eIF 2 and its recycling factor eukaryotic translation initiation factor 2B ( eIF 2B ) in a way that diminishes the inhibitory effect of phosphorylated eIF 2 on the essential function of eIF 2B in translation initiation . ^^^ These mutations may identify a region in eIF 2 alpha that participates directly in a physical interaction with the GCN 3 subunit of eIF 2B . . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Purification of eukaryotic initiation factors eIF 2 , eIF 2B and eIF 2 alpha kinase from bovine liver . ^^^ Eukaryotic initiation factors 2 and 2B ( eIF 2 ; eIF 2B ) are components of the rate limiting step in the initiation of eukaryotic protein synthesis and are involved in the regulation of this process . ^^^ When the alpha subunit of eIF 2 is phosphorylated by an eIF 2 alpha kinase , the phosphorylated eIF 2 alpha ( eIF 2 alpha ( P ) ) binds tightly to eIF 2B and prevents the recycling of eIF 2 . ^^^ Therefore , procedures were developed for the simultaneous purification of eIF 2 , eIF 2B and eIF 2 alpha kinase from kilogram quantities of fresh bovine liver . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
We identify here the translational initiation complex , eIF 4F , and the guanine nucleotide exchange factor for eIF 2 , eIF 2B , as the rate controlling components of protein synthesis in immature oocytes of the starfish , Pisaster orchraceus . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
We have proposed that reducing eIF 2 activity by phosphorylation of its alpha subunit or by a mutation in the eIF 2 recycling factor eIF 2B allows ribosomes which have translated the 5 ' proximal uORF 1 to bypass uORF 2 to uORF 4 and reinitiate at GCN 4 instead . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
We investigated the possible mechanisms responsible for these differential changes in peptide chain initiation between liver and skeletal muscle during sepsis by measuring the cellular content of eukaryotic initiation factor 2 ( eIF 2 ) , the extent of phosphorylation of the alpha subunit of eIF 2 , and the activity of eIF 2B . ^^^ In liver , neither the extent of phosphorylation of eIF 2 alpha nor the activity of eIF 2B was different in rats with a sterile or septic abscess compared with control . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Mutations in the GCD 7 subunit of yeast guanine nucleotide exchange factor eIF 2B overcome the inhibitory effects of phosphorylated eIF 2 on translation initiation . ^^^ Phosphorylation of the alpha subunit of eukaryotic translation initiation factor 2 ( eIF 2 alpha ) impairs translation initiation by inhibiting the guanine nucleotide exchange factor for eIF 2 , known as eIF 2B . ^^^ These suppressor mutations , affecting eIF 2 alpha and the essential subunits of eIF 2B encoded by GCD 7 and GCD 2 , do not reduce the level of eIF 2 alpha phosphorylation in cells expressing the activated GCN2c kinase . ^^^ We propose that GCD 7 and GCD 2 play important roles in the regulatory interaction between eIF 2 and eIF 2B and that the suppressor mutations we isolated in these genes decrease the susceptibility of eIF 2B to the inhibitory effects of phosphorylated eIF 2 without impairing the essential catalytic function of eIF 2B in translation initiation . . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
SRD 1 encodes a putative 225 amino acid , 26 kDa protein containing a C2 / C2 zinc finger motif that is also found in some transcription regulators and the eIF 2 beta translation initiating factors . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
The eukaryotic protein synthesis initiation factor , eIF 2B , is a multimeric protein of five different subunits termed alpha , beta , gamma , delta and epsilon , which facilitates recycling of a further factor , eIF 2 , and is an important control point in the initiation process . ^^^ Quantitative studies showed substantial variation in the relative concentrations of eIF 2 and eIF 2B between different rabbit tissues . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Isolation and characterization of the Drosophila melanogaster gene encoding translation initiation factor eIF 2 beta . ^^^ The aa sequence comparison of D . melanogaster eIF 2 beta with its human and yeast counterparts demonstrates a high degree of similarity , especially within the C terminal region . ^^^ Northern analysis indicates quasi constitutive expression of eIF 2 beta throughout D . melanogaster development . . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Rabbit eIF 2 beta transcripts were then specifically amplified by PCR and sequenced . ^^^ Comparison of the deduced amino acid sequence with that of human eIF 2 beta reveals a very high degree of sequence identity . . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Previous genetic and biochemical experiments led to the conclusion that GCD 1 , GCD 2 , and GCN 3 are components of the GCD complex , recently shown to be the yeast equivalent of the mammalian guanine nucleotide exchange factor for eIF 2 , known as eIF 2B . ^^^ Biochemical experiments showing that GCD 6 and GCD 7 copurify and coimmunoprecipitate with GCD 1 , GCD 2 , GCN 3 , and subunits of eIF 2 have confirmed that GCD 6 and GCD 7 are subunits of the GCD eIF 2B complex . ^^^ The fact that all five subunits of yeast eIF 2B were first identified as translational regulators of GCN 4 strongly suggests that regulation of guanine nucleotide exchange on eIF 2 is a key control point for translation in yeast cells just as in mammalian cells . . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Preparation of a cell free translation system with minimal loss of initiation factor eIF 2 / eIF 2B activity . ^^^ The block resulted from a decrease in eukaryotic initiation factor 2 ( eIF 2 ) or the guanine nucleotide exchange factor ( eIF 2B ) activity , since the addition of eIF 2 or eIF 2B to these latter extracts substantially improved the capacity of the extract to initiate translation of exogenous mRNA . ^^^ We show that the method of cell extract preparation greatly influences the state of eIF 2 / eIF 2B activity in the resulting extract and that extracts in which this activity is maintained can readily initiate translation on exogenous mRNA and reinitiate on endogenous mRNA . . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
We have identified the GCD 11 gene product as the gamma subunit of eIF 2 by the following criteria : ( 1 ) sequence identities with mammalian eIF 2 gamma peptides ; ( 2 ) increased eIF 2 activity in extracts prepared from cells cooverexpressing GCD 11 , eIF 2 alpha , and eIF 2 beta ; and ( 3 ) cross reactivity of antibodies directed against the GCD 11 protein with the 58 kDa polypeptide present in purified yeast eIF 2 . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Analysis of polysome profiles and determination of both eukaryotic initiation factor 2 ( eIF 2 ) activity and amount of eIF 2 beta protein in the liver of fetal and 1 h old neonatal rats , indicate a rapid activation of translation initiation without changes in the amount of the translational machinery available between both stages of liver development . ^^^ Appearance of a more acidic eIF 2 beta subunit form in two dimensional Western blots from 1 h old rat livers suggests that covalently regulated modifications of the initiation factor phosphoproteins might be responsible for increased translation in the neonatal liver . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
The results presented here demonstrate that changes in eIF 2 alpha phosphorylation are not responsible for the effect of diabetes on eIF 2B activity in fast twitch skeletal muscle . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
We find that both GCD 6 and GCD 7 show sequence similarities to components of a high molecular weight complex ( the GCD complex ) that appears to be the yeast equivalent of translation initiation factor 2B ( eIF 2B ) , which catalyzes GDP GTP exchange on eIF 2 . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Similar to the increase in ribosomes and mRNA , the number of eIF 2 alpha , eIF 2 beta , and eIF 4 alpha molecules per cell also increase 2 3 fold . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
In mammalian cells , phosphorylation of eIF 2 alpha inhibits the activity of eIF 2B , the GDP GTP exchange factor for eIF 2 . ^^^ We present biochemical evidence that five translational regulators of GCN 4 encoded by GCD 1 , GCD 2 , GCD 6 , GCD 7 , and GCN 3 are components of a protein complex that stably interacts with eIF 2 and represents the yeast equivalent of eIF 2B . ^^^ This finding suggests that mutations in GCD encoded subunits of the complex derepress GCN 4 translation because they mimic eIF 2 alpha phosphorylation in decreasing eIF 2B activity . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
A difference in the rate of ribosomal elongation balances the synthesis of eukaryotic translation initiation factor ( eIF ) 2 alpha and eIF 2 beta . ^^^ Northern analysis of K 562 cell mRNA revealed that eIF 2 beta was five times more abundant than eIF 2 alpha . ^^^ Addition of equal amounts of synthetic capped mRNA for eIF 2 alpha and eIF 2 beta to an in vitro translation reaction produced five times more eIF 2 alpha protein than eIF 2 beta . ^^^ Determination of the polysome profile for alpha and beta mRNA in K 562 cells indicated eIF 2 alpha was translated more efficiently than eIF 2 beta . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Computer assisted analysis of amino acid sequences using methods for database screening with individual sequences and with multiple alignment blocks reveals a complex multidomain organization of yeast proteins GCD 6 and GCD 1 , and mammalian homolog of GCD 6 subunits of the eukaryotic translation initiation factor eIF 2B involved in GDP / GTP exchange on eIF 2 . ^^^ It is hypothesized that the nucleotidyltransferase related domain is directly involved in the GDP / GTP exchange , whereas the C terminal conserved domain may be involved in the interaction of eIF 2B , eIF 4 gamma , and eIF 5 with eIF 2 . . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
The best characterized mechanism for modulating eIF 2B activity involves changes in the phosphorylation of the alpha subunit of its substrate eIF 2 . ^^^ However , in islets , no change in eIF 2 alpha phosphorylation was seen under conditions where eIF 2B activity was increased , implying that glucose regulates eIF 2B via an alternative pathway . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
The exchange reaction mediated by eIF 2B can be regulated by phosphorylation of eIF 2 on its alpha subunit . ^^^ Mutational analysis in Saccharomyces cerevisiae suggested that the smallest subunit ( the alpha ) is dispensable for exchange , but required for the inhibition of eIF 2B by eIF 2 ( alphaP ) . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
This diminished guanine nucleotide exchange activity was due to the inhibition of eukaryotic initiation factor eIF 2B , the factor required for the dissociation of GDP from eIF 2 , and the formation of the functional eIF 2 . ^^^ The autocrine effect of IFN resulted in elevated PKR activity , increased phosphorylation of eIF 2 alpha , and diminished eIF 2B activity . ^^^ These results suggest that interferon regulates the initiation of protein synthesis by a mechanism involving PKR , eIF 2 alpha phosphorylation , and eIF 2B activity . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Phosphorylation of eIF 2alpha impairs the guanine nucleotide exchange activity of eIF 2B and thereby inhibits or shuts off protein synthesis . ^^^ Delayed addition of hemin to shut off lysates inhibits the eIF 2alpha kinase activity of HRI and restores protein synthesis ; under those conditions , the endogenous phosphatase of the lysate dephosphorylates phosphorylated eIF 2alpha and restores eIF 2B activity . ^^^ The recovery of eIF 2B activity is not affected by protein synthesis inhibitors such as cycloheximide , pactamycin and puromycin , which do not affect the eIF 2alpha phosphorylation . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Addition of eIF 2 and of eIF 2B changed the selection process for both types of RNA . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
The activity of eIF 2B is inhibited indirectly by phosphorylation of the smallest subunit of eIF 2 which sequesters eIF 2B into an inactive eIF 2 ( alpha P ) . eIF 2B complex . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Eukaryotic initiation factor 2B ( eIF 2B ) is a guanine nucleotide exchange protein involved in the recycling of eIF 2 during peptide chain initiation . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Among them are six known sequences coding for : acid sphingomyelinase , fibronectin , SPARC , nm 23 metastasis suppressor protein , and two translation factors , eIF 2 beta and EF 1 alpha . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
To determine whether this mechanism operates in primary neuronal cells , we have cultured primary neuronal cells for 7 days under two optimal growing conditions , complete medium ( containing 15 % serum ) and serum free medium , and determined the protein synthesis rate , eukaryotic initiation 2 and 2B ( eIF 2B ) activities , as well as the level of phosphorylation of eIF 2 . ^^^ Cells cultured in serum free medium exhibited a lower rate of protein synthesis ( 75 % ) , concomitant to a decreased eIF 2 activity ( 71 % ) , and slightly higher eIF 2 ( alpha P ) levels ( from 10 to 16 % of total eIF 2 ) with respect to cells cultured in complete media . eIF 2B activity , as measured at saturating eIF 2 . ^^^ The increased levels of eIF 2 ( alpha P ) , a competitive inhibitor of eIF 2B in the guanine exchange reaction , are responsible for the decreased eIF 2B activity found in the neurons cultured in serum free medium . ^^^ Additionally , eIF 2 ( alpha P ) is accountable for the lower effect of exogenous eIF 2B in ternary complex formation from preformed eIF 2 . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
To study the effect of prolonged diabetes on protein synthesis and on the activities of initiation factors eIF 2 and eIF 2B in the liver , female rats were treated with streptozotocin . ^^^ The isoelectric forms of the beta subunit of eIF 2 factor , eIF 2 beta , were different in the diabetic and the control animals , indicating that insulin deficiency modifies the phosphorylation of specific substrates . ^^^ Since no differences were detected in RNA or eIF 2 content between control and diabetic rats , translation may , at least partly , be inhibited in the liver by an impairment of peptide chain initiation caused by the decreased eIF 2B activity which nevertheless is independent of eIF 2 alpha phosphorylation . . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Identification of a regulatory subcomplex in the guanine nucleotide exchange factor eIF2B that mediates inhibition by phosphorylated eIF 2 . ^^^ Eukaryotic translation initiation factor 2B ( eIF2B ) is a five subunit complex that catalyzes guanine nucleotide exchange on eIF 2 . ^^^ Phosphorylation of the alpha subunit of eIF 2 [ creating eIF 2 ( alphaP ] ) converts eIF 2 10 GDP from a substrate to an inhibitor of eIF2B . ^^^ We showed previously that the inhibitory effect of eIF 2 ( alphaP ) can be decreased by deletion of the eIF2B alpha subunit ( encoded by GCN 3 ) and by point mutations in the beta and delta subunits of eIF2B ( encoded by GCD 7 and GCD 2 , respectively ) . ^^^ These findings , plus sequence similarities among GCD 2 , GCD 7 , and GCN 3 , led us to propose that these proteins comprise a regulatory domain that interacts with eIF 2 ( alphaP ) and mediates the inhibition of eIF2B activity . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
The guanine nucleotide exchange factor eIF2B mediates the exchange of GDP bound to translation initiation factor eIF 2 for GTP . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Homologous segments in three subunits of the guanine nucleotide exchange factor eIF2B mediate translational regulation by phosphorylation of eIF 2 . eIF2B is a five subunit guanine nucleotide exchange factor that is negatively regulated by phosphorylation of the alpha subunit of its substrate , eIF 2 , leading to inhibition of translation initiation . ^^^ To analyze this regulatory mechanism , we have characterized 29 novel mutations in the homologous eIF2B subunits encoded by GCD 2 , GCD 7 , and GCN 3 that reduce or abolish inhibition of eIF2B activity by eIF 2 phosphorylated on its alpha subunit [ eIF 2 ( alphaP ) ] . ^^^ Most , if not all , of the mutations decrease sensitivity to eIF 2 ( alphaP ) without excluding GCN 3 , the nonessential subunit , from eIF2B ; thus , all three proteins are critical for regulation of eIF2B by eIF 2 ( alphaP ) . ^^^ We propose that these segments form a single domain in eIF2B that makes multiple contacts with the alpha subunit of eIF 2 , around the phosphorylation site , allowing eIF2B to detect and respond to phosphoserine at residue 51 . ^^^ Most of the eIF 2 is phosphorylated in certain mutants , suggesting that these substitutions allow eIF2B to accept phosphorylated eIF 2 as a substrate for nucleotide exchange . . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Phosphorylation of the substrate eIF 2 inhibited the GEF activity of the five subunit eIF 2B ; this inhibition required the eIF 2B alpha subunit . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
The p 38 subunit of wheat eIF 2 is therefore the equivalent of mammalian eIF2beta . . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
The increased eIF 2alpha phosphorylation that occurs at high concentrations of PQQ inhibits eIF 2B activity , presumably due to formation of a 15S complex [ eIF 2 ( alphaP ) . eIF 2B ] in which eIF 2B becomes non functional . ^^^ The effects of pyrroloquinoline quinone on heme regulated eIF 2alpha kinase and eIF 2B activities in eukaryotic protein synthesis . ^^^ This inhibition is characterized by increased phosphorylation of eIF 2alpha and by diminished guanine nucleotide exchange activity of eIF 2B . ^^^ Low concentrations of PQQ ( 0 . 1 1 microM ) do not affect eIF 2alpha phosphorylation , but rather enhance the guanine nucleotide exchange activity of eIF 2B in reticulocyte lysates . ^^^ In Chinese hamster ovary cell extract which is devoid of significant eIF 2alpha kinase activity , addition of both low and high concentrations of PQQ results in an increase in eIF 2B activity . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Addition of eukaryotic initiation factor eIF 2 , eIF 2B , cAMP , MgGTP , or dithiothreitol neither prevented nor reversed the inhibition induced by cisplatin , indicating that the mechanism of cisplatin induced translational inhibition is distinct from the inhibition induced by other toxic heavy metal ions ( Hurst , R . , Schatz , J . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Catalysis of guanine nucleotide exchange on eIF 2 by eIF 2B : is it a sequential or substituted enzyme mechanism . ^^^ The mechanism of action of the eukaryotic initiation factor eIF 2B in catalyzing the exchange of guanine nucleotides bound to eIF 2 is uncertain evidence having been adduced for a sequential mechanism and for a substituted enzyme mechanism . ^^^ Suitable rate constants for a sequential mechanism involving the transient formation of the quaternary complex eIF 2 . eIF 2B . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Fasting and refeeding caused alterations in translation initiation in both skeletal muscle and liver that were not associated with any detectable changes in the activity of eIF2B or in the phosphorylation state of eIF 2 alpha . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Eukaryotic initiation factor 2B ( eIF2B ) is a guanine nucleotide exchange factor which mediates the exchange of GDP ( bound to initiation factor eIF 2 ) for GTP , thus regenerating the active [ eIF2 . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
This suggestion is also consistent with the findings that vanadium compounds do not stimulate phosphorylation of the alpha ( alpha ) subunit of initiation factor 2 ( eIF 2 ) or decrease the guanine nucleotide exchange activity of eIF2B , which is required to exchange GDP for GTP in eIF2 . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
We also show that NF 90 , NF 45 , and eIF 2 beta are substrates for DNA PK in vitro . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Identification of interprotein interactions between the subunits of eukaryotic initiation factors eIF 2 and eIF2B . ^^^ Specifically , regulation of the interaction of eIF 2 with the guanine nucleotide exchange factor , eIF2B , is a key mechanism for controlling translation under a variety of conditions . ^^^ Phosphorylation of the alpha subunit of eIF 2 converts the protein into a competitive inhibitor of eIF2B by causing an increase in the binding affinity of eIF2B for eIF 2 . ^^^ Consequently , it has been assumed that the alpha subunit of eIF 2 is directly involved in binding to eIF2B . ^^^ In the present study , eIF 2 was found to bind only to the delta and epsilon subunits of eIF2B , and eIF2B was shown to bind only to the beta subunit of eIF 2 by far Western blot analysis . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
We have used an in vitro nucleotide exchange assay to show that wild type yeast eIF2B is inhibited by phosphorylated eIF 2 [ eIF 2 ( alphaP ) ] and to characterize eIF2B regulatory mutations that render translation initiation insensitive to eIF 2 phosphorylation in vivo . ^^^ Unlike wild type eIF2B , eIF2B complexes with mutated GCN 3 or GCD 7 subunits efficiently catalyzed GDP exchange using eIF 2 ( alphaP ) as a substrate . ^^^ Using an affinity binding assay , we show that an eIF2B subcomplex of the GCN 3 , GCD 7 , and GCD 2 subunits binds to eIF 2 and has a higher affinity for eIF 2 ( alphaP ) , but it lacks nucleotide exchange activity . ^^^ In contrast , the GCD 1 and GCD 6 subunits form an eIF2B subcomplex that binds equally to eIF 2 and eIF 2 ( alphaP ) . ^^^ Remarkably , this second subcomplex has higher nucleotide exchange activity than wild type eIF2B that is not inhibited by eIF 2 ( alphaP ) . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Phosphorylation of the translation initiation factor eIF 2alpha downregulates protein synthesis by sequestering the guanylate exchange factor eIF 2B . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Herein , we explore the evolutionary relationships among the components of bacterial initiation factor 2 ( IF 2 ) and eukaryotic IF 2 ( eIF 2 ) / eIF 2B , i . e . , the initiation factors involved in introducing the initiator tRNA into the translation mechanism and performing the first step in the peptide chain elongation cycle . ^^^ All Archaea appear to posses a fully functional eIF 2 molecule , but they lack the associated GTP recycling function , eIF 2B ( a five subunit molecule ) . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
The alpha subunit of eukaryotic initiation factor eIF 2 ( eIF2alpha ) plays an important role in the regulation of mRNA translation through modulation of the interaction of eIF 2 and a second initiation factor , eIF2B . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
The majority of the known GCD genes encode subunits of the general translation initiation factor eIF 2 or eIF 2B . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Both the five and four subunit forms of eIF2B exhibit similar rates of guanine nucleotide exchange activity using unphosphorylated eIF 2 as substrate . ^^^ In contrast , eIF2B lacking the alpha subunit is insensitive to inhibition by eIF 2 ( alphaP ) and is able to exchange guanine nucleotide using eIF 2 ( alphaP ) as substrate at a faster rate compared with five subunit eIF2B . ^^^ Finally , a double point mutation in the delta subunit of eIF2B has been identified that results in insensitivity to inhibition by eIF 2 ( alphaP ) and exhibits little exchange activity when eIF 2 ( alphaP ) is used as substrate . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Eukaryotic initiation factor eIF2B plays a key role in the regulation of protein synthesis through its ability to catalyze the exchange of GDP bound to a second initiation factor , eIF 2 , for free GTP . ^^^ The purified five subunit eIF2B complex had high GEF activity as assayed by using [ 3H ] GDP bound to eIF 2 as a substrate . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
We examined the isoforms of eIF4B and the alpha and beta subunits of eIF 2 during the development and germination of wheat seed to determine whether the differences in their phosphorylation state are because of tissue specific regulation or occur concomitant with changes in protein synthetic activity during development . eIF2alpha underwent phosphorylation through several intermediate isoforms that correlated with the increase and subsequent reduction in protein synthetic activity characteristic of seed development . eIF2beta and eIF4B , present as highly phosphorylated isoforms during early seed development , underwent dephosphorylation during late development . eIF4B was rapidly phosphorylated within 20 h of germination , whereas eIF2alpha did not undergo dephosphorylation until 48 60 h of growth . ^^^ These observations suggest that the phosphorylation state of eIF2alpha , eIF2beta , and eIF4B is developmentally regulated in a way that correlates with the changes in protein synthetic activity but that some differences were also observed . . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
At mild heat shock temperatures the main cause for inhibition is the inactivation of the guanine nucleotide exchange factor eukaryotic initiation factor 2B ( eIF2B ) ; under more severe heat shock conditions the activity of several initiation factors is compromised . eIF2B is required for GDP / GTP exchange on eIF 2 , which delivers methionyl tRNA to the 40 S ribosomal subunit . ^^^ In agreement with observations in cells exposed to mild heat shocks , the thermal inactivation of eIF2B could be ascribed to neither eIF2alpha phosphorylation nor the induction of another inhibitor . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Hsc 70 suppressed eIF 2alpha phosphorylation and maintained the guanine nucleotide exchange activity of eIF 2B in heme deficient RRL and in hemin supplemented RRL exposed to elevated temperatures ( 42 degrees C ) , denatured protein ( reduced carboxymethylated bovine serum albumin , RCM BSA ) , oxidized glutathione or Hg2+ . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
The changes in eIF2B activity could be explained in part by modulation of the phosphorylation state of the alpha subunit of eIF 2 . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Our findings show that Rps 31 deficient ribosomes are altered in a way that decreases the eIF2B requirement and that the small ribosomal subunit mediates the effects of low eIF2B activity on cell viability and translational regulation in response to eIF 2 phosphorylation . . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
All such mutations in the beta subunit of eIF 2 ( eIF2beta ) mapped to a region containing a putative zinc finger structure of the C 2 C2 type , indicating that these sequences could be involved in RNA recognition . ^^^ We further show that only one run of lysine residues is sufficient for the in vivo function of eIF2beta , probably through charge interaction , since its replacement by arginines did not impair cell viability , whereas substitution for alanines resulted in inviable cells . mRNA binding , but not GTP dependent initiator Met tRNAMet binding , by the eIF 2 complex was determined to be dependent on the presence of the lysine runs of the beta subunit . . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Similar to the eIF2alpha promoter , the eIF2beta promoter is TATA less , CAAT less , and GC rich and contains an alpha Pal binding motif . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
In the initiation phase of eukaryotic translation , eIF 5 stimulates the hydrolysis of GTP bound to eIF 2 in the 40S ribosomal pre initiation complex , and the resultant GDP on eIF 2 is replaced with GTP by the complex nucleotide exchange factor , eIF2B . ^^^ We also find that three lysine rich boxes in the N terminal segment of eIF2beta mediate the binding of eIF 2 to both eIF 5 and eIF2B . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
The exchange of GDP bound to eIF 2 for GTP is a prerequisite to binding Met tRNAi and is mediated by a second initiation factor , eIF2B . ^^^ In what is probably the best characterized mechanism for the regulation of mRNA translation , phosphorylation of eIF 2 on its smallest , or alpha , subunit converts eIF 2 from a substrate of eIF2B into a competitive inhibitor . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Phosphorylation of Ser ( 51 ) on the alpha subunit of eIF 2 [ eIF2alpha ( P ) ] generates a competitive inhibitor of eIF2B , thereby preventing the replenishment of GTP onto eIF 2 , thus blocking translation initiation . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Serine 48 in initiation factor 2 alpha ( eIF 2 alpha ) is required for high affinity interaction between eIF 2 alpha ( P ) and eIF2B . ^^^ Phosphorylation of the serine 51 residue in the alpha subunit of translational initiation factor 2 in eukaryotes ( eIF 2 alpha ) impairs protein synthesis presumably by sequestering eIF2B , a rate limiting pentameric guanine nucleotide exchange protein which catalyzes the exchange of GTP for GDP in the eIF 2 GDP binary complex . ^^^ To further understand the importance of eIF 2 alpha phosphorylation in the interaction between eIF 2 alpha ( P ) and eIF2B proteins and thereby the regulation of eIF2B activity , we expressed the wild type ( wt ) and a mutant eIF 2 alpha in which the serine 48 residue was replaced with alanine ( 48A mutant ) in the baculovirus system . ^^^ Furthermore , the extents of inhibition of eIF2B activity and formation of the eIF 2 alpha ( P ) eIF2B complex that occurs due to eIF 2 alpha phosphorylation in poly ( IC ) treated rabbit reticulocyte lysates were decreased significantly in the presence of insect cell extracts expressing the 48A mutant eIF 2 alpha compared to those for wt . ^^^ These findings support the hypothesis that the serine 48 residue is required for high affinity interaction between eIF 2 alpha ( P ) and eIF2B . . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
The effects of nutrients on the activation of eIF2B do not reflect changes in the phosphorylation of eIF 2 ( and , by inference , operation of a kinase analogous to yeast Gcn2p ) , or a requirement for nutrients for inactivation of glycogen synthase kinase 3 or dephosphorylation of eIF2B . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
The mechanism for the increased protein synthesis and growth appeared to be a transcriptional upregulation of the eIF 2alpha and eIF 2beta genes . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Moreover , the guanine nucleotide exchange activity of eIF2B was unaffected as was phosphorylation of the alpha subunit of eIF 2 . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
To address the role of C . elegans PEK in translational control , we expressed this kinase in yeast and found that it inhibits growth by hyperphosphorylation of eIF 2alpha and inhibition of eIF 2B . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
In contrast , no differences in the phosphorylation state of eIF2alpha or the activity of eIF2B were noted among treatment groups . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Analysis showed that after caspase cleavage , exchange of GDP bound to eIF 2 was very rapid and no longer dependent upon eIF2B . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Here we provide a comparative sequence analysis of the beta subunit of eIF 2 and its archaeal counterpart ( aIF2beta ) . aIF2beta differs from eIF2beta in not possessing an N terminal extension implicated in binding RNA , eIF 5 and eIF2B . ^^^ Previously isolated mutations in the yeast eIF2beta , which allow initiation of translation at UUG codons due to the uncovering of an intrinsic GTPase activity in eIF 2 , involve residues that are conserved in aIF2beta , but not in eIF 5 . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Hepatic eIF2B activity was decreased 24 % in alcohol treated rats , and this was associated with a 95 % increase in eIF2alpha phosphorylation . ^^^ In contrast to liver , neither eIF2B activity nor the phosphorylation of eIF2alpha was affected in muscle of alcohol treated rats . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Eukaryotic translation initiation factor 2B ( eIF2B ) is the guanine nucleotide exchange factor for protein synthesis initiation factor 2 ( eIF 2 ) . ^^^ We have analyzed the roles of different regions of eIF2Bepsilon in catalysis , in eIF2B complex formation , and in binding to eIF 2 by characterizing mutations in the Saccharomyces cerevisiae gene encoding eIF2Bepsilon ( GCD 6 ) that impair the essential function of eIF2B . ^^^ Finally , missense mutations identified within this region do not affect the catalytic activity of eIF2Bepsilon alone or its interactions with the other eIF2B subunits or with eIF 2 . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
The content of eIF2alpha or the amount of eIF2alpha in the phosphorylated form did not change in response to LPS . eIF2B activity was decreased in muscle 4 h post LPS but activity returned to control values by 24 h . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Eukaryotic translation initiation factor 2B ( eIF2B ) is the heteropentameric guanine nucleotide exchange factor for translation initiation factor 2 ( eIF 2 ) . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
These findings suggest that plant eIF2alpha is capable of interacting with the guanine nucleotide exchange factor eIF2B within the context of the eIF 2 holoenzyme and provide direct evidence for its ability to participate in phosphorylation mediated translational control in vivo . . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Eukaryotic translation initiation factor , eIF2B , is a guanine nucleotide exchange factor ( GEF ) composed of five dissimilar subunits . eIF2B is important for regenerating GTP bound eIF 2 during the initiation process . ^^^ Removal of the C terminal 552 amino acids of eIF2B epsilon markedly reduced its interaction with the beta subunit of eIF 2 whereas loss of the N terminal 431 amino acids did not . ^^^ In contrast , the C terminal domain of eIF2B epsilon is sufficient alone for binding the beta subunit of its substrate , eIF 2 , in vitro . . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Protein synthesis is not inhibited by the high eIF2alpha phosphorylation in carcinoma cells , probably because they contain higher levels of eIF2B , the initiation factor that is inhibited by eIF2alpha phosphorylation . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
We show that yeast eIF 5 can bridge interaction in vitro between eIF 3 and eIF 2 by binding simultaneously to the amino terminus of eIF 3 subunit NIP 1 and the amino terminal half of eIF2beta , dependent on a conserved bipartite motif in the carboxyl terminus of eIF 5 . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Phosphorylation of serine 51 in initiation factor 2 alpha ( eIF 2 alpha ) promotes complex formation between eIF 2 alpha ( P ) and eIF2B and causes inhibition in the guanine nucleotide exchange activity of eIF2B . ^^^ Inhibition of the GNE activity of eIF2B leads to impairment in eIF 2 recycling and protein synthesis . ^^^ Analysis of these mutants has provided novel insight into the role of 51 serine in the interaction between eIF 2 and eIF2B . ^^^ Our results show that the increased interaction between eIF 2 and eIF2B protein , occurring in reticulocyte lysates due to increased eIF2alpha phosphorylation , is decreased significantly by the addition of mutant 51A protein but not 51D . ^^^ Phosphorylation of serine 51 residue on the alpha subunit of eukaryotic initiation factor 2 ( eIF2alpha ) inhibits the guanine nucleotide exchange ( GNE ) activity of eIF2B , presumably , by forming a tight complex with eIF2B . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
The alpha subunit of eIF 2 plays a critical role in regulating nucleotide exchange via phosphorylation at serine 51 , which converts eIF 2 into a competitive inhibitor of the eIF2B catalyzed exchange reaction . ^^^ These data indicate that eIF2alpha is required for structural interactions between eIF 2 and eIF2B that promote wild type rates of nucleotide exchange . ^^^ Biochemical analysis of the eIF2beta gamma complex reveals a structural function for eIF2alpha in catalyzed nucleotide exchange . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Acute alcohol intoxication did not significantly alter the myocardial content of eIF 2 alpha or eIF2B epsilon , the extent of eIF 2 alpha phosphorylation , or the activity of eIF2B . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Eukaryotic initiation factor ( eIF ) 2B catalyzes a key regulatory step in the initiation of mRNA translation . eIF2B is well characterized in mammals and in yeast , although little is known about it in other eukaryotes . eIF2B is a hetropentamer which mediates the exchange of GDP for GTP on eIF 2 . ^^^ Extracts of D . melanogaster S 2 Schneider cells display eIF2B activity , which is inhibited by phosphorylation of eIF2alpha , showing the insect factor is regulated similarly to eIF2B from other species . ^^^ In S 2 cells , serum starvation increases eIF2alpha phosphorylation , which correlates with inhibition of eIF2B , and both effects are reversed by serum treatment . ^^^ This shows that eIF2alpha phosphorylation and eIF2B activity are under dynamic regulation by serum . eIF2alpha phosphorylation is also increased by endoplasmic reticulum stress in S 2 cells . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
In this work , we show that , in addition to the eIF 2 beta binding region at the C terminus of eIF 5 , the N terminal region of eIF 5 is also required for eIF 5 dependent GTP hydrolysis . ^^^ Mutation of this arginine residue to alanine or even to conservative lysine caused a severe defect in the ability of eIF 5 to promote GTP hydrolysis from the 40 S initiation complex , although the ability of these mutant proteins to bind to eIF 2 beta remained unchanged . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
The association between plant eIF2alpha and yeast eIF2B is supported by their specific coimmunoprecipitation from transgenic yeast cells . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Phosphorylation of eIF2alpha converts the factor from a substrate into a competitive inhibitor of the guanine nucleotide exchange factor , eIF2B , leading to a decline in mRNA translation . ^^^ Furthermore , the reduction in eIF2B activity is associated with enhanced phosphorylation of eIF2alpha . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Eukaryotic translation initiation factor 2 ( eIF 2 ) is a G protein heterotrimer required for GTP dependent delivery of initiator tRNA to the ribosome . eIF2B , the nucleotide exchange factor for eIF 2 , is a heteropentamer that , in yeast , is encoded by four essential genes and one nonessential gene . ^^^ We found that increased levels of wild type eIF 2 , in the presence of sufficient levels of initiator tRNA , overcome the requirement for eIF2B in vivo . ^^^ The effects described are further enhanced in the presence of a mutation in the G protein ( gamma ) subunit of eIF 2 , gcd 11 K250R , which mimics the function of eIF2B in vitro . ^^^ Our results suggest that the eIF2betagamma complex is capable of carrying out the essential function ( s ) of eIF 2 in the absence of eIF2alpha and eIF2B and are consistent with the idea that the latter function primarily to regulate the level of eIF2 . ^^^ Consistent with bypassing eIF2B , these conditions also suppress the lethal effect of overexpressing the mammalian tumor suppressor PKR , an eIF2alpha kinase . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Increased phosphorylation of the alpha subunit of eIF 2 ( eIF 2 alpha ) and eIF2B inhibition paralleled the inhibition of translation in the hippocampus , but they normalized to control values , including the CA 1 subfield , after 4 6 h of reperfusion . eIF4E and 4E BP 1 were significantly dephosphorylated during ischaemia and total eIF4E levels decreased during reperfusion both in the cortex and hippocampus , with values normalizing after 4 h of reperfusion only in the cortex . ^^^ Our findings are consistent with a potential role for eIF4E , 4E BP 1 and eIF4G in the down regulation of translation during ischaemia . eIF 2 alpha , eIF2B , eIF4G and p 70 ( S6K ) are positively implicated in the translational inhibition induced at early reperfusion , whereas eIF4F complex formation is likely to contribute to the persistent inhibition of translation observed at longer reperfusion times . . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Phosphorylation of eIF2alpha was inversely related to eIF2B activity under all conditions . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
They lie at the extreme C terminus and are required for the interaction of eIF2Bepsilon with its substrate , eIF 2 , in vivo and for eIF2B activity in vitro . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Since BDNF and insulin increased the activity of eIF2B and eIF 2 , the only difference between them was eIF4E phosphorylation . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Phosphorylated eIF 2 acts as a dominant inhibitor of the guanine nucleotide exchange factor eIF2B and prevents the recycling of eIF 2 between successive rounds of protein synthesis . ^^^ Extensive phosphorylation of eIF 2 alpha and strong inhibition of eIF2B activity can result in the downregulation of the overall rate of protein synthesis ; less marked changes may lead to alterations in the selective translation of alternative open reading frames in polycistronic mRNAs , as demonstrated in yeast . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Activation of GCN 2 results in increased phosphorylation of the alpha subunit of eIF 2 , which in turn causes inhibition of eIF2B . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Up regulated expression of eIF 2 beta mRNA was confirmed by reverse Northern dot blot analysis . eIF 2 beta , together with eIF 2 alpha and eIF 2 gamma , comprise subunits of a complex that promotes the binding of methionyl tRNA to ribosomes during the initiation of protein translation . ^^^ The nucleotide sequence of the chick eIF 2 beta cDNA predicts a protein of 334 amino acids that has 95 % , 93 % , 56 % and 37 % sequence identity with rabbit , human , drosophila and yeast eIF 2 beta , respectively . ^^^ The deduced eIF 2 beta protein contains a number of functional motifs and domains consistent with the putative function of this protein ; these include a potential C 2 C2 zinc finger binding domain , three polylysine regions , and three acidic regions . . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Catalysis of guanine nucleotide exchange on eIF 2 by eIF2B : can it be both a substituted enzyme and a sequential mechanism . ^^^ There are conflicting reports over the question of whether the displacement by GTP of GDP bound to eIF 2 catalyzed by eIF2B follows a substituted enzyme mechanism , as is believed to be the case for other guanine nucleotide exchange factors , or is a sequential mechanism . ^^^ Chem . 276 , 24697 24703 , 2001 ) showing displacement by eIF2B of GDP bound to eIF 2 in the absence of displacing nucleotide appears to offer a way of resolving the dispute and suggests that both mechanisms may be operative . . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
This diminished activity was not caused by a reduction in the content of eIF 2B epsilon or the content and phosphorylation state of eIF 2 alpha . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
An alternative mechanism for regulating eIF2B is through phosphorylation of the alpha subunit of eIF 2 , which converts it into an inhibitor of eIF2B . ^^^ CCK , CCh , A 23187 , and thapsigargin all enhanced eIF2alpha phosphorylation , suggesting that eIF2B activity is regulated by eIF2alpha phosphorylation under these conditions . ^^^ Removal of Ca ( 2+ ) from the medium enhanced the inhibitory action of CCK on both protein synthesis and eIF2B activity as well as further increasing eIF2alpha phosphorylation . ^^^ Although it is likely that other mechanisms account for the stimulation of acinar protein synthesis , these results suggest that the inhibition of acinar protein synthesis by CCK occurs as a result of depletion of Ca ( 2+ ) from the endoplasmic reticulum lumen leading to phosphorylation of eIF2alpha and inhibition of eIF2B . . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
The unsolved patients were investigated by mutation analysis of the genes encoding the alpha , gamma , and delta subunit of eIF2B and the gene encoding the alpha subunit of eIF 2 , because phosphorylation of this latter subunit regulates eIF2B activity . ^^^ Mutations were found in the genes encoding the alpha ( 1 patient ) , gamma ( 2 patients ) , and delta subunits ( 2 patients ) of eIF2B , but no mutations were found in the gene encoding the alpha subunit of eIF 2 . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Here , we reported that the first and the third SH 3 domains of Nck 1 interact with the C terminal region of the beta subunit of the eukaryotic initiation factor 2 ( eIF 2 beta ) . ^^^ Binding of eIF 2 beta was specific to the SH 3 domains of Nck 1 , and in vivo , the interaction Nck / eIF2 beta was demonstrated by reciprocal coimmunoprecipitations . ^^^ In addition , Nck was detected in a molecular complex with eIF 2 beta in an enriched ribosomal fraction , whereas no other SH2 / SH3 domain containing adapters were found . ^^^ This effect of Nck 1 required the integrity of its first and third SH 3 domains originally found to interact with eIF 2 beta . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Thus the impaired interaction of these two subunits represents a novel type of defect in eIF 2 function , providing in vivo evidence that the strength of interaction between eIF2beta and eIF2gamma defines the correct usage of the AUG codon for translation initiation . . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Histidine limitation in the presence of histidinol induced a twofold increase in the phosphorylation of eIF2alpha and a concomitant reduction in eIF2B activity in perfused livers from wild type mice , but no changes in livers from Gcn 2 ( / ) mice . . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
For protein synthesis initiation in eukaryotes , eIF2B is the guanine nucleotide exchange factor for eIF 2 . eIF2B is an essential multi subunit factor and a major target for translational control in both yeast and mammalian cells . ^^^ Finally , we show that the catalytic domain can provide eIF2B biological function in vivo when elevated levels eIF 2 and tRNA ( 1 ) ( Met ) are also present . . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
In the present study , we show in both NIH 3T3 cells and mouse embryo fibroblasts that stress granules contain not only eIF 2 but also the guanine nucleotide exchange factor for eIF 2 , eIF2B . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
The guanine nucleotide exchange activity of eIF2B was repressed , phosphorylation of the alpha subunit of eIF 2 was enhanced , and phosphorylation of eIF4E binding protein 1 and ribosomal protein S 6 kinase was reduced . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
We found that the vast majority of translation initiation factors ( eIF 2 , eIF2B , eIF 3 , eIF4A1 , eIF 5 and eIF5B ) , all three elongation factors ( eEF1A , eEF1B and eEF 2 ) and the termination factor eRF 1 are strictly excluded from nuclei . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
In this study , we investigated ischemia induced changes in protein levels and phosphorylation states of the initiation factors eIF2alpha , eIF2B epsilon , and eIF4G1 and of p 70 S6 kinase , proteins playing a central role in the control of the initiation of translation . ^^^ Transient ischemia caused a long lasting suppression of global protein synthesis . eIF2alpha was transiently phosphorylated after ischemia , peaking at 1 3 h of recovery . eIF2B epsilon and p 70 S6 kinase were completely dephosphorylated during ischemia and phosphorylation did not recover completely following reperfusion . ^^^ Thus , several different processes contributed to ischemia induced suppression of the initiation of protein synthesis : a long lasting dephosphorylation of eIF2B epsilon and p 70 S6K starting during ischemia , a transient phosphorylation of eIF2alpha during early reperfusion , and a marked decrease of eIF2B epsilon , eIF4G1 , and p 70 S6K protein levels starting during vascular occlusion ( eIF4G1 ) . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Regions corresponding to the human phosphorylation and kinase docking sites are identical in the proteins of both fish species , as are residues that interact with the eIF 2 recycling factor , eIF2B . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Inhibition of acinar protein synthesis can be mediated by inhibition of eIF2B following phosphorylation of eIF2alpha . . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Caerulein inhibited the two major regulatory points of translation initiation : the activity of the guanine nucleotide exchange factor eIF2B ( with an increase of eIF2alpha phosphorylation ) and the formation of the eIF4F complex due , in part , to degradation of eIF4G . ^^^ Thus the inhibition of pancreatic protein synthesis in this model of AP most likely results from the inhibition of translation initiation as a result of increased eIF2alpha phosphorylation , reduction of eIF2B activity , and the inhibition of eIF4F complex formation . . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Eukaryotic translation initiation factor eIF2beta binds to protein kinase CK 2 : effects on CK2alpha activity . eIF 2 ( eukaryotic translation initiation factor 2 ) is a substrate and an interacting partner for CK 2 ( protein kinase CK 2 ) . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Events regulating the binding of initiator methionyl tRNA to the 40S ribosomal subunit were assessed through eIF2B activity and eIF 2 alpha phosphorylation on Ser 51 . ^^^ No differences were noted with either eIF2B or eIF 2 alpha . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Burn failed to alter eIF2B activity or the total amount or phosphorylation status of either eIF 2 alpha or eIF2B epsilon in heart . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Structure of the archaeal translation initiation factor aIF 2 beta from Methanobacterium thermoautotrophicum : implications for translation initiation . aIF 2 beta is the archaeal homolog of eIF 2 beta , a member of the eIF 2 heterotrimeric complex , implicated in the delivery of Met tRNA ( 1 ) ( Met ) to the 40S ribosomal subunit . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Our findings imply CACH / VWM mutations do not specifically impair responses to eIF 2 phosphorylation , but instead cause protein structure defects that impair eIF2B activity . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
To examine the properties of archaeal initiation factor 2 alpha ( aIF 2 alpha ) , three genes encoding alpha , beta , and gamma subunits of aIF 2 from the hyperthermophilic archaeon Pyrococcus horikoshii OT 3 were expressed in Escherichia coli cells , and the resulting proteins , aIF 2 alpha , aIF 2 beta , and aIF 2 gamma , were characterized with reference to the properties of eIF 2 . aIF 2 alpha preferentially interacts with aIF 2 gamma , but does not interact with aIF 2 beta , which is consistent with data obtained with eIF 2 , of which eIF 2 gamma serves as a core subunit , interacting with eIF 2 alpha and eIF 2 beta . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Eukaryotic translation initiation factor 2B ( eIF2B ) is the guanine nucleotide exchange factor for eukaryotic initiation factor 2 ( eIF 2 ) . eIF2B is a heteropentameric protein composed of alpha subunits . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Surprisingly , during this period protein synthesis , relative RNA content , eIF2B activity , relative eIF 2 expression , and S6K1 phosphorylation all increased . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Translational control is exerted primarily during initiation by two mechanisms : 1 ) through inhibition of translation initiation complex formation via sequestration of the cap binding protein , eukaryotic initiation factor ( eIF ) 4E , with inhibitory 4E binding proteins ( 4E BP ) ; and 2 ) by prevention of eIF 2 GTP tRNA ( 1 ) ( Met ) formation and eIF2B activity by phosphorylated eIF2alpha . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Eukaryotic initiation factor eIF 2 and its ' exchange factor ' eIF2B play a key role in the regulation of protein synthesis in eukaryotes from yeast to mammals . ^^^ Phosphorylation of eIF 2 inhibits eIF2B and thus translation initiation . ^^^ The importance of correct control of eIF 2 and eIF2B for normal physiology is exemplified by data from transgenic mice carrying knock in or knock out mutations and by the fact that mutations in the genes for the eIF 2 kinase PERK or for eIF2B give rise to serious human diseases . . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Phosphorylated eIF 2 is an inhibitor of its guanine nucleotide exchange factor , eIF2B . ^^^ Thus , two structurally distinct effectors of eIF 2 function , eIF2alpha kinases and eIF2B , have evolved to recognize the same surface and overlapping determinants on eIF2alpha . . ^^^ PKR and GCN 2 kinases and guanine nucleotide exchange factor eukaryotic translation initiation factor 2B ( eIF2B ) recognize overlapping surfaces on eIF2alpha . ^^^ In contrast , mutations that blocked translational regulation but not Ser 51 phosphorylation impaired the binding of eIF2B to phosphorylated eIF2alpha . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Both responses are elicited by phosphorylation of translation initiation factor 2 ( eIF 2 ) and the attendant inhibition of its nucleotide exchange factor eIF2B decreasing the binding to 40S ribosomes of methionyl initiator tRNA in the ternary complex ( TC ) with eIF 2 and GTP . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
We show that although the cells expressing mutant eIF2B genes respond normally to stress conditions by reduced global translation rates , they exhibit significantly greater increase in ATF 4 induction compared to normal controls despite equal levels of stress and activity of the upstream eIF2alpha kinase . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Dynamic cycling of eIF 2 through a large eIF2B containing cytoplasmic body : implications for translation control . ^^^ The eukaryotic translation initiation factor 2B ( eIF2B ) provides a fundamental controlled point in the pathway of protein synthesis . eIF2B is the heteropentameric guanine nucleotide exchange factor that converts eIF 2 , from an inactive guanosine diphosphate bound complex to eIF 2 guanosine triphosphate . ^^^ Here we demonstrate that in contrast to other translation initiation factors , eIF2B and eIF 2 colocalize to a specific cytoplasmic locus . ^^^ Indeed eIF 2 shuttles into these foci whereas eIF2B remains largely resident . ^^^ Three different strategies to decrease the guanine nucleotide exchange function of eIF2B all inhibit eIF 2 shuttling into the foci . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
The mutations in eIF2B did not affect the interaction with eIF 2 . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Mutation at Ser 2 and Ser 67 did not affect eIF2beta integrating into the eIF 2 trimer or being able to complex with eIF 5 and CK2alpha . ^^^ The eIF2beta CT form was also incorporated into the eIF 2 trimer but did not bind to eIF 5 . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
The large spectrum of eIF2B related diseases . eIF2B ( eukaryotic initiation factor 2B ) is a GEF ( guanine nucleotide exchange factor ) that plays , with its substrate eIF 2 , a key regulatory role in the translation initiation phase of protein synthesis . ^^^ The importance of correct control of eIF 2 and eIF2B for normal physiology is underlined by the recent involvement of the five genes that encode the five eIF2B subunits in a severe autosomal recessive neurodegenerative disease , described in young children as CACH ( childhood ataxia with central nervous system hypomyelination ) / VWM ( leukoencephalopathy with vanishing white matter ) syndrome . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Interaction of recombinant human eIF 2 subunits with eIF2B and eIF2alpha kinases . ^^^ Consistent with this observation , the beta subunit specifically interacts with the purified eIF2B in ELISA studies and this interaction is enhanced when wt eIF2alpha in the recombinant trimeric complex is phosphorylated or replaced by a mutant phosphomimetic eIF2alpha ( S51D ) . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
We examined whether supplementation of HeLa cell extracts with any translation initiation factor or translational regulator could enhance protein synthesis . eIF 2 ( eukaryotic translation initiation factor 2 ) and eIF2B augmented translation of capped , uncapped and encephalomyocarditis virus internal ribosome entry site promoted mRNAs . eIF4E specifically stimulated capped mRNA translation , while p 97 , a homologue to the C terminal two thirds of eIF4G , increased uncapped mRNA translation . ^^^ When the HeLa cell extract was supplemented with a combination of eIF 2 , eIF2B , and p 97 , the capacity to synthesize a protein from an uncapped mRNA became comparable to that from the capped counterpart stimulated with a combination of eIF 2 , eIF2B , and eIF4E . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
This is accompanied by inhibition of activity of the guanine nucleotide exchange factor eIF2B that is responsible for GDP GTP exchange on eIF 2 . ^^^ At lower doses , neither eIF2alpha phosphorylation nor eIF2B activity is altered . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
The factor eIF 5 stimulates hydrolysis of GTP by eIF 2 upon AUG codon recognition , whereas the factor eIF2B promotes guanine nucleotide exchange on eIF 2 to recycle the factor for additional rounds of translation initiation . ^^^ The GTP binding ( G ) domain resides in the gamma subunit of the heterotrimeric eIF 2 ; however , only eIF2beta , and not eIF2gamma , has been reported to directly bind to eIF 5 or eIF2B . ^^^ Thus , rather than allosterically regulating eIF2gamma G domain function via eIF2beta , our data support a model in which the GTPase activating factor eIF 5 and the guanine nucleotide exchange factor eIF2B modulate eIF 2 function through direct interactions with the eIF2gamma G domain . . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Since eIF2B is required for recycling of eIF 2 , a factor required for all cytoplasmic translation initiation events , this will contribute to overall activation of protein synthesis . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Recently , we have found that the eIF2B guanine nucleotide exchange factor resides in a specific cytoplasmic focus in the yeast , Saccharmoyces cerevisiae . eIF2B is a resident feature of this focus , whereas eIF 2 shuttles to and fro . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Ischemia and reperfusion also resulted in increased phosphorylation of eIF 2 and eIF2B . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
The IF 5 CTD interacts directly with the translation initiation factors eIF 1 , eIF 2 beta , and eIF3c , thus forming together with eIF 2 bound Met tRNA ( 1 ) ( Met ) the MFC . ^^^ The binding sites of eIF 2 beta , eIF 3 and eIF 1 were mapped onto the structure . eIF 2 beta and eIF 3 bind to non overlapping patches of negative and positive electrostatic potential , respectively . . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
Studies from yeast two hybrid assays show that p 67 interacts strongly with eIF2gamma , relatively weakly with eIF2alpha , and no interaction with eIF2beta . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
GDP binds the pentameric factor eIF2B for guanine nucleotide exchange . eIF 5 and the eIF2Bvarepsilon catalytic subunit possess a conserved eIF 2 binding site . ^^^ Nearly half of cellular eIF 2 forms a complex with eIF 5 lacking Met tRNA ( 1 ) ( Met ) , and here we investigate its physiological significance . eIF 5 overexpression increases the abundance of both eIF2 / eIF5 and TC / eIF5 complexes , thereby impeding eIF2B reaction and MFC formation , respectively . eIF2Bvarepsilon mutations , but not other eIF2B mutations , enhance the ability of overexpressed eIF 5 to compete for eIF 2 , indicating that interaction of eIF2Bvarepsilon with eIF 2 normally disrupts eIF2 / eIF5 interaction . ^^^ We propose that the eIF2 / eIF5 complex represents a cytoplasmic reservoir for eIF 2 that antagonizes eIF2B promoted guanine nucleotide exchange , enabling coordinated regulation of translation initiation . . ^^^
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
NA
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
NA
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
NA
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
NA
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
NA
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
NA
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
NA
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
NA
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
NA
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
NA
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
NA
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
NA
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
NA
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
NA
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
NA
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
NA
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
NA
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
NA
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
NA
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
NA
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
NA
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
NA
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
NA
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
NA
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
NA
Interacting proteins: Q9NR50 and P05198	Pubmed	SVM Score :0.0
NA