| Interacting proteins: Q92186 and P13591 |
Pubmed |
SVM Score :0.0 |
| NA |
|
| Interacting proteins: Q92186 and P13591 |
Pubmed |
SVM Score :0.0 |
| NA |
|
| Interacting proteins: Q92186 and P13591 |
Pubmed |
SVM Score :0.0 |
| NA |
|
| Interacting proteins: Q92186 and P13591 |
Pubmed |
SVM Score :0.0 |
| NA |
|
| Interacting proteins: Q92186 and P13591 |
Pubmed |
SVM Score :0.0 |
| NA |
|
| Interacting proteins: Q92186 and P13591 |
Pubmed |
SVM Score :0.0 |
| NA |
|
| Interacting proteins: Q92186 and P13591 |
Pubmed |
SVM Score :0.0 |
| NA |
|
| Interacting proteins: Q92186 and P13591 |
Pubmed |
SVM Score :0.0 |
| It has been shown that two enzymes , polysialyltransferase , PST , and sialyltransferase 10 , STX , form polysialic acid on N CAM . ^^^ |
|
| Interacting proteins: Q92186 and P13591 |
Pubmed |
SVM Score :0.0 |
| Comparisons between PST and another polysialyltransferase , sialyltransferase 10 ( STX ) , are made and it is demonstrated that both enzymes can independently form polysialic acid in vitro , but that during neural development they coordinately but distinctly synthesize polysialic acid on N CAM . ^^^ |
|
| Interacting proteins: Q92186 and P13591 |
Pubmed |
SVM Score :0.0 |
| Only the 140 and 180 kDa isoforms of NCAM in N2a STX cells were specifically polysialylated in vivo , although other membrane proteins of N2a STX were polysialylated in vitro . ^^^ |
|
| Interacting proteins: Q92186 and P13591 |
Pubmed |
SVM Score :0.0 |
| PST and STX are polysialyltransferases that form polysialic acid in the neural cell adhesion molecule ( N CAM ) , although it is not known why these two polysialyltransferases exist . ^^^ HeLa cells doubly transfected with the isolated STX cDNA and N CAM cDNA supported neurite outgrowth much better than HeLa cells expressing N CAM alone . ^^^ |
|
| Interacting proteins: Q92186 and P13591 |
Pubmed |
SVM Score :0.0 |
| Hamster PST 1 ( PST ) and rat STX are two related sialytransferases that catalyze the polysialylation of N CAM . ^^^ The distribution of PST and STX mRNAs , polysialic acid , and N CAM were analyzed at three developmental stages . ^^^ The results suggest that both PST and STX participate in the polysialylation of N CAM in vivo and that their expression levels are dynamically controlled during development and regeneration . . ^^^ |
|
| Interacting proteins: Q92186 and P13591 |
Pubmed |
SVM Score :0.0 |
| PST and STX are polysialyltransferases that form polysialic acid in the neural cell adhesion molecule ( NCAM ) , and these two polysialyltransferases often exist together in the same tissues . ^^^ To determine the individual and combined roles of PST and STX in polysialic acid synthesis , in the present study we asked if PST and STX differ in the acceptor requirement and if PST and STX act together in polysialylation of NCAM . ^^^ We first examined whether PST and STX differ in the requirement of sialic acid and core structures of N glycans attached to NCAM . ^^^ PST and STX were found to add polysialic acid on NCAM . ^^^ These results indicate that both PST and STX have relatively broad specificity on N glycan core structures in NCAM and no remarkable difference exists between PST and STX for the requirement of core structures and sialic acid attached to the N glycans of NCAM . ^^^ |
|
| Interacting proteins: Q92186 and P13591 |
Pubmed |
SVM Score :0.0 |
| PST ( ST8Sia 4 ) and STX ( ST8Sia 2 ) are the two polysialyltransferases responsible for NCAM polysialylation . ^^^ |
|
| Interacting proteins: Q92186 and P13591 |
Pubmed |
SVM Score :0.0 |
| So far , two polysialyltransferase enzymes , STX and PST , have been characterized for their capacity to transfer PSA onto NCAM in vitro . ^^^ |
|
| Interacting proteins: Q92186 and P13591 |
Pubmed |
SVM Score :0.0 |
| Differential biosynthesis of polysialic acid on neural cell adhesion molecule ( NCAM ) and oligosaccharide acceptors by three distinct alpha 2 , 8 sialyltransferases , ST8Sia 4 ( PST ) , ST8Sia 2 ( STX ) , and ST8Sia 3 . ^^^ Polysialylation of NCAM was shown to be achieved by two alpha 2 , 8 polysialyltransferases , ST8Sia 4 ( PST ) and ST8Sia 2 ( STX ) , which are moderately related to another alpha 2 , 8 sialyltransferase , ST8Sia 3 . ^^^ |
|
| Interacting proteins: Q92186 and P13591 |
Pubmed |
SVM Score :0.0 |
| Second , it suggests that synthesis of di and / or oligo Sia units may be catalyzed by alpha 2 > 8 sialyltransferase ( s ) that are distinct from the known polysialyltransferases , STX and PST , which are partially responsible for polysialylation of N CAM . . ^^^ |
|
| Interacting proteins: Q92186 and P13591 |
Pubmed |
SVM Score :0.0 |
| ST8Sia 2 ( STX ) and ST8Sia 4 ( PST ) are polysialic acid ( polySia ) synthases that catalyze polySia formation of neural cell adhesion molecule ( NCAM ) in vivo and in vitro . ^^^ |
|
| Interacting proteins: Q92186 and P13591 |
Pubmed |
SVM Score :0.0 |
| Polysialylation of the neural cell adhesion molecule ( NCAM ) is catalyzed by two polysialyltransferases , ST8Sia 2 ( STX ) and ST8Sia 4 ( PST ) , which contain sialylmotifs L and S conserved in all members of the sialyltransferases . ^^^ |
|
| Interacting proteins: Q92186 and P13591 |
Pubmed |
SVM Score :0.0 |
| Polysialyltransferase ST8Sia 2 ( STX ) polysialylates all of the major isoforms of NCAM and facilitates neurite outgrowth . ^^^ |
|
| Interacting proteins: Q92186 and P13591 |
Pubmed |
SVM Score :0.0 |
| Two enzymes , the alpha 2 , 8 polysialyltransferases ST8Sia 4 ( ) / PST and ST8Sia 2 ( ) / STX are responsible for the polysialylation of NCAM . ^^^ However , whether the autopolysialylation of ST8Sia II / STX is required for its ability to polysialylate NCAM is unknown . ^^^ Coexpression of a nonautopolysialylated ST8Sia II / STX mutant with NCAM demonstrated that autopolysialylation is not required for ST8Sia II / STX polysialyltransferase activity . ^^^ Furthermore , immunoblot analysis of NCAM polysialylation by autopolysialylated and nonautopolysialylated ST8Sia II / STX suggests that the NCAM is polysialylated to a higher degree by autopolysialylated ST8Sia II / STX . ^^^ Therefore , we conclude that autopolysialylation of ST8Sia II / STX , like that of ST8Sia IV / PST , is not required for , but does enhance , NCAM polysialylation . . ^^^ |
|
| Interacting proteins: Q92186 and P13591 |
Pubmed |
SVM Score :0.0 |
| Two closely related polysialyltransferases , ST8Sia 2 ( STX ) and ST8Sia 4 ( PST ) have been cloned previously and shown to synthesize polysialic acid on NCAM and other glycoproteins . ^^^ |
|
| Interacting proteins: Q92186 and P13591 |
Pubmed |
SVM Score :0.0 |
| However , N butanoylmannosamine and N pentanoylmannosamine are effective inhibitors of polysialic acid ( PSA ) synthesis in stably transfected HeLa cells expressing NCAM and the polysialyltransferase STX . ^^^ |
|
| Interacting proteins: Q92186 and P13591 |
Pubmed |
SVM Score :0.0 |
| Polysialylation of NCAM is catalyzed by two polysialyltransferases , ST8Sia 2 ( STX ) and ST8Sia 4 ( PST ) , which belong to the family of six genes encoding alpha 2 , 8 sialyltransferases . ^^^ |
|
| Interacting proteins: Q92186 and P13591 |
Pubmed |
SVM Score :0.0 |
| NCAM polysialylation can occur via either of two specific sialyltransferases , ST8SiaII ( STX ) and ST8SiaIV ( PST ) , and the purpose of this study was to determine if retroviral delivery of either PST or STX could induce PSA expression in vivo and thereby alter tissue plasticity . ^^^ |
|
| Interacting proteins: Q92186 and P13591 |
Pubmed |
SVM Score :0.0 |
| Cells were transduced with a retrovirus encoding polysialyl transferase STX , an enzyme that synthesizes PSA on NCAM . ^^^ |
|
| Interacting proteins: Q92186 and P13591 |
Pubmed |
SVM Score :0.0 |
| We show that basal synaptic transmission , measured as the slope of field excitatory postsynaptic potentials , was reduced strongly in mice lacking ST8SiaII / STX , the enzyme involved in polysialylation of NCAM in stem cell derived immature granule cells , but not in mice deficient either in the NCAM glycoprotein or the enzyme ST8SiaIV / PST involved in polysialylation of NCAM in mature neurons . ^^^ Strikingly , only mice deficient in NCAM , but not in PST or STX , were impaired in long term potentiation ( LTP ) induced by theta burst stimulation , suggesting that LTP in the dentate gyrus depends on the NCAM glycoprotein alone rather than on its associated PSA . ^^^ |
|
| Interacting proteins: Q92186 and P13591 |
Pubmed |
SVM Score :0.0 |
| To investigate which of two PSA synthase ( ST8Sia 2 and 4 ) are involved in the biosynthesis of PSA associated with NCAM , the expressions of PSA , PSA synthase activity , and the genes of two PSA synthases during in vitro neuronal differentiation of mouse embryonal carcinoma P 19 cells were determined . ^^^ |
|
| Interacting proteins: Q92186 and P13591 |
Pubmed |
SVM Score :0.0 |
| We previously cloned cDNAs encoding two different polysialic acid ( PSA ) synthases , ST8Sia 2 and 4 , from mouse , and showed that both mouse ST8Sia 2 and 4 can synthesize PSA on the neural cell adhesion molecule ( NCAM ) as well as other glycoproteins such as fetuin , at least in vitro ( Kojima , N . , Tachida , Y . , Yoshida , Y . , and Tsuji , S . ( 1996 ) J . ^^^ Western blotting with an anti NCAM polyclonal antibody showed that NCAM was expressed as the polysialylated form in both ST8Sia 2 cDNA transfected and ST8Sia 4 cDNA transfected Neuro2a cells , but that the polysialylated NCAMs expressed in ST8Sia 4 cDNA transfected clones migrated much slower on SDS PAGE than those expressed in ST8Sia 2 cDNA transfected clones . ^^^ The slower migration of polysialylated NCAM of the ST8Sia 4 cDNA transfected clone ( N2a 4 ) than that of the ST8Sia 2 cDNA transfected clone ( N2a 2 ) was also observed when cells were metabolically labeled with [ 3H ] glucosamine or pulse chase labeled with [ 35S ] methionine followed by immunoprecipitation with anti PSA antibody or anti NCAM monoclonal antibody . ^^^ In N2a 4 , NCAM 120 , 140 , and 180 were expressed as polysialylated forms , while polysialylation was restricted to NCAM 140 and 180 , i . e . , not NCAM 120 , in N2a ST8Sia 2 . ^^^ |
|
| Interacting proteins: Q92186 and P13591 |
Pubmed |
SVM Score :0.0 |
| Two polysialyltransferases , ST8Sia 2 and ST8Sia 4 , play dominant roles in polysialic acid synthesis on NCAM . ^^^ Previous studies indicate that ST8Sia 4 forms more highly polysialylated N glycans on NCAM than ST8Sia 2 in vitro . ^^^ In the present study , we first demonstrated that a combination of ST8Sia 2 and ST8Sia 4 cooperatively polysialylated NCAM , resulting in NCAM N glycans containing more , and thus longer , polysialic acid than when the enzymes were used individually . ^^^ There was also an increase in polysialylated NCAM when we used ST8Sia 2 and ST8Sia 4 sequentially , whereas there appeared to be a subtle increase when the enzymes were used in the reverse order . ^^^ On the other hand , neither ST8Sia 2 nor ST8Sia 4 could add polysialic acid to a polysialylated antenna of NCAM N glycans . ^^^ |
|
| Interacting proteins: Q92186 and P13591 |
Pubmed |
SVM Score :0.0 |
| Two highly homologous polysialyltransferases , ST8Sia 2 and ST8Sia 4 , which belong to the sialyltransferase gene family , synthesize polysialic acid on NCAM . ^^^ By contrast , ST8Sia 3 , which is moderately homologous to ST8Sia 2 and ST8Sia 4 , adds oligosialic acid to itself but very inefficiently to NCAM . ^^^ Here , we report domains of polysialyltransferases required for NCAM recognition and polysialylation by generating chimeric enzymes between ST8Sia 4 and ST8Sia 3 or ST8Sia 2 . ^^^ To identify domains responsible for NCAM polysialylation , different segments of the ST8Sia 4 catalytic domain , identified by the deletion experiments , were replaced with corresponding segments of ST8Sia 2 and ST8Sia 3 . ^^^ |
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| Interacting proteins: Q92186 and P13591 |
Pubmed |
SVM Score :0.0 |
| The potential of this new method was evaluated using a nonpolysialylated construct of N CAM that was polysialylated in vitro using a soluble construct of ST8Sia 2 or ST8Sia 4 . ^^^ |
|
| Interacting proteins: Q92186 and P13591 |
Pubmed |
SVM Score :0.0 |
| BACKGROUND : Sialyltransferase 8B ( SIAT8B ) and 8D ( SIAT8D ) are two polysialyltransferases that catalyze the transfer of polysialic acid ( PSA ) to the neural cell adhesion molecule 1 ( NCAM 1 ) . ^^^ |
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| Interacting proteins: Q92186 and P13591 |
Pubmed |
SVM Score :0.0 |
| Two enzymes , the polysialyltransferases ST8SiaII and ST8SiaIV , are known to be involved in the polysialylation of NCAM . ^^^ |
|
| Interacting proteins: Q92186 and P13591 |
Pubmed |
SVM Score :0.0 |
| Control of NCAM polysialylation by the differential expression of polysialyltransferases ST8SiaII and ST8SiaIV . ^^^ |
|
| Interacting proteins: Q92186 and P13591 |
Pubmed |
SVM Score :0.0 |
| In vitro and transfection approaches revealed that ST8SiaII and ST8SiaIV are independently capable of synthesizing PSA on NCAM with slightly different specificities towards the major NCAM isoforms and glycosylation sites . ^^^ |
|
| Interacting proteins: Q92186 and P13591 |
Pubmed |
SVM Score :0.0 |
| Two enzymes , the polysialyltransferases ST8SiaIV and ST8SiaII , are known to be involved in the polysialylation of NCAM . ^^^ |
|
| Interacting proteins: Q92186 and P13591 |
Pubmed |
SVM Score :0.0 |
| The polysialyltransferases [ ST8SiaIV ( PST 1 ) and ST8SiaII ] are responsible for the addition of polysialic acid ( PSA ) to NCAM . ^^^ |
|
| Interacting proteins: Q92186 and P13591 |
Pubmed |
SVM Score :0.0 |
| To dissect polySia and NCAM functions , we generated polySia negative but NCAM positive mice by simultaneous deletion of the two polysialyltransferase genes , St8sia 2 and St8sia 4 . ^^^ |
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