| Interacting proteins: Q02846 and Q9UMX6 |
Pubmed |
SVM Score :0.0 |
| These results demonstrate that GCAP 1 is an activator of ROS GC , while the finding of a second activator , GCAP 2 , suggests that a similar mechanism of GC regulation may be present in outer segments , other subcellular compartments of the photoreceptor , or other cell types . . ^^^ |
|
| Interacting proteins: Q02846 and Q9UMX6 |
Pubmed |
SVM Score :0.0 |
| This cyclase shares a high sequence identity with ROS GC , is specifically expressed in the bovine retina , and , like ROS GC , is modulated in low Ca2+ by a calmodulin like Ca2+ binding protein , termed GCAP 2 . ^^^ |
|
| Interacting proteins: Q02846 and Q9UMX6 |
Pubmed |
SVM Score :0.0 |
| Guanylyl cyclase activating protein 2 ( GCAP 2 ) is a Ca2+ binding protein that activates RetGC 1 in a Ca2+ sensitive manner . ^^^ To establish whether GCAP 2 stimulates RetGC 1 through the ECD or ICD , we made deletion mutants lacking either the ECD or both the ECD and transmembrane domains ( TMD ) of RetGC 1 . ^^^ Recombinant wild type RetGC 1 and both deletion mutants were expressed in HEK 293 cells , and their sensitivities to GCAP 2 , Ca2+ , and ATP were compared . ^^^ Our data demonstrate that both deletion mutants are regulated similarly to wild type RetGC 1 with indistinguishable EC 50 values for Ca2+ and similar K1 / 2 values for activation by GCAP 2 . ^^^ This shows that GCAP 2 functions through the ICD of RetGC 1 and that removal of the ECD and TMD do not significantly alter regulation by these factors . ^^^ |
|
| Interacting proteins: Q02846 and Q9UMX6 |
Pubmed |
SVM Score :0.0 |
| RetGC 1 and RetGC 2 are photoreceptor membrane guanylyl cyclases that are regulated by the Ca2+ binding protein , GCAP 2 . ^^^ We used a protease protection assay to localize regions of the intracellular domains of RetGCs important for the interaction with GCAP 2 and found that GCAP 2 reduces the access of trypsin to a site in the kinase homology domain ( KHD ) of RetGC 1 . ^^^ We also found that RetGC 2 and GCAP 2 interact cooperatively with high affinity , but RetGC 1 and GCAP 2 interact noncooperatively with low affinity . ^^^ By analyzing RetGC 1 / RetGC 2 chimeras we demonstrated that the affinity and cooperativity of the interaction with GCAP 2 is dictated by the structure of the KHD . ^^^ These findings suggest that GCAP 2 interacts constituitively with the KHDs of RetGC 1 and RetGC 2 and that cGMP synthesis is controlled by Ca2+ dependent conformational changes in the RetGC / GCAP complex . . ^^^ |
|
| Interacting proteins: Q02846 and Q9UMX6 |
Pubmed |
SVM Score :0.0 |
| Substitution of these three domains in GCAP 2 with corresponding neurocalcin sequences also affects activation of individual recombinant RetGC 1 and RetGC 2 expressed in HEK 293 cells . . ^^^ |
|
| Interacting proteins: Q02846 and Q9UMX6 |
Pubmed |
SVM Score :0.0 |
| It reduces the overall catalytic ability of RetGC 1 and dramatically reduces stimulation by GCAP 2 , although GCAP 2 still appears to interact with the protein . ^^^ |
|
| Interacting proteins: Q02846 and Q9UMX6 |
Pubmed |
SVM Score :0.0 |
| The photoreceptor membrane guanylyl cyclases , RetGC 1 and RetGC 2 ( also referred to as GC E and GC F ) , are regulated intracellularly by two Ca ( 2+ ) binding proteins , GCAP 1 and GCAP 2 . ^^^ |
|
| Interacting proteins: Q02846 and Q9UMX6 |
Pubmed |
SVM Score :0.0 |
| Point mutations within the EF 1 region can interfere with both the activation of the cyclase by the Ca ( 2+ ) free form of GCAP 2 and the inhibition of retGC basal activity by the Ca ( 2+ ) loaded GCAP 2 . ^^^ |
|
| Interacting proteins: Q02846 and Q9UMX6 |
Pubmed |
SVM Score :0.0 |
| When photoreceptor outer segment homogenates are preincubated with AMP PNP ( EC 50 = 0 . 65 + / 0 . 20 mM ) , GCAP 2 enhanced the retGC activity 10 13 times over the control rate . ^^^ The large activation is due to a GCAP 2 dependent increase in Vmax without an alteration of retGC affinity for GCAP 2 ( EC 50 = 47 . 9 + / 2 . 7 nM ) . ^^^ |
|
| Interacting proteins: Q02846 and Q9UMX6 |
Pubmed |
SVM Score :0.0 |
| The present study shows that : ( 1 ) GCAP 2 is a specific modulator of ROS GC 2 ; ( 2 ) through systematic remodeling of ROS GC modules , the study also shows that the modulated domain resides within the amino acid segment 736 1020 . ^^^ |
|
| Interacting proteins: Q02846 and Q9UMX6 |
Pubmed |
SVM Score :0.0 |
| The other GCAP protein , GCAP 2 , which is also a known modulator of ROS GC in photoreceptors , was not present in the pineal gland . ^^^ |
|
| Interacting proteins: Q02846 and Q9UMX6 |
Pubmed |
SVM Score :0.0 |
| Guanylyl cyclase activating protein 2 ( GCAP 2 ) is a recoverin like calcium binding protein that regulates photoreceptor guanylyl cyclase ( RetGC ) ( Dizhoor , A . ^^^ We found that compartmentalization of GCAP 2 in photoreceptor outer segment membranes is Ca2+ and ionic strength sensitive , but it does not require the presence of the fatty acyl group and does not necessarily directly reflect GCAP 2 interaction with RetGC . ^^^ The lack of myristoylation does not significantly affect the ability of GCAP 2 to stimulate RetGC . ^^^ Nor does it affect the ability of the Ca2+ loaded form of GCAP 2 to compete with the GCAP 2 mutant that constitutively activates RetGC . ^^^ Guanylyl cyclase activating protein 2 ( GCAP 2 ) is a recoverin like calcium binding protein that regulates photoreceptor guanylyl cyclase ( RetGC ) ( Dizhoor , A . ^^^ |
|
| Interacting proteins: Q02846 and Q9UMX6 |
Pubmed |
SVM Score :0.0 |
| Photoreceptor membrane guanylate cyclases ( RetGC ) are regulated by calcium binding proteins , GCAP 1 and GCAP 2 . ^^^ Instead , the Y104C GCAP 2 stimulates RetGC less efficiently than the wild type GCAP 2 . ^^^ |
|
| Interacting proteins: Q02846 and Q9UMX6 |
Pubmed |
SVM Score :0.0 |
| The ability of GCAP 2 and its several mutants to activate retGC in vitro correlates with their ability to dimerize at low free Ca ( 2+ ) concentrations . ^^^ A constitutively active GCAP 2 mutant E80Q / E116Q / D158N that stimulates retGC regardless of the free Ca ( 2+ ) concentrations forms dimers both in the absence and in the presence of Ca ( 2+ ) . ^^^ Several GCAP 2 / neurocalcin chimera proteins that can not efficiently activate retGC in low Ca ( 2+ ) concentrations are also unable to dimerize in the absence of Ca ( 2+ ) . ^^^ |
|
| Interacting proteins: Q02846 and Q9UMX6 |
Pubmed |
SVM Score :0.0 |
| Functionally therefore , the retGC 2 and GCAP 2 mutations are similar in reducing the feedback inhibition of Ca2+ on cyclase activity and thereby on cGMP levels in the photoreceptors . . ^^^ |
|
| Interacting proteins: Q02846 and Q9UMX6 |
Pubmed |
SVM Score :0.0 |
| GCAP 1 and GCAP 2 regulated ROS GC 1 activities differently . ^^^ |
|
| Interacting proteins: Q02846 and Q9UMX6 |
Pubmed |
SVM Score :0.0 |
| In rod phototransduction , cyclic GMP synthesis by membrane bound guanylate cyclase ROS GC 1 is under Ca ( 2+ ) dependent negative feedback control mediated by guanylate cyclase activating proteins , GCAP 1 and GCAP 2 . ^^^ The cellular concentration of GCAP 1 and GCAP 2 approximately sums to the cellular concentration of a functional ROS GC 1 dimer . ^^^ However , the presence of a myristoyl group in GCAP 1 has a strong impact on the regulation of ROS GC 1 , this is in contrast to GCAP 2 . ^^^ The findings show that differences in catalytic efficiency and Ca ( 2+ ) sensitivity of ROS GC 1 are conferred by GCAP 1 and GCAP 2 . ^^^ |
|
| Interacting proteins: Q02846 and Q9UMX6 |
Pubmed |
SVM Score :0.0 |
| This study maps the GCAP 2 modulatory site in ROS GC 1 through the use of multiple techniques involving surface plasmon resonance binding studies with soluble ROS GC 1 constructs , coimmunoprecipitation , functional reconstitution experiments with deletion mutants , and peptide competition assays . ^^^ The findings show that the sequence motif of the core GCAP 2 modulatory site is Y 965 N981 of ROS GC 1 . ^^^ |
|
| Interacting proteins: Q02846 and Q9UMX6 |
Pubmed |
SVM Score :0.0 |
| Inactivation of the CNDPK phosphorylation site in GCAP 2 by substitutions S201G or S201D , as well as phosphorylation or thiophosphorylation of Ser ( 201 ) , had little effect on the ability of GCAP 2 to regulate retGC in reconstituted membranes in vitro . ^^^ |
|
| Interacting proteins: Q02846 and Q9UMX6 |
Pubmed |
SVM Score :0.0 |
| In the present study the GCAP 2 dependent Ca2+ modulation of the cyclase activity has been reconstituted using recombinant forms of GCAP 2 and ROS GC 1 , and its mutants . ^^^ The results indicate that consistent to phototransduction , GCAP 2 at low Ca2+ concentration ( 10 nM ) maximally stimulates the cyclase activity of the wild type and its mutants : ext ( deleted aa 8 408 ) , kin ( deleted aa 447 730 ) and hybrid consisting of the ext , transmembrane and kin domains of ANF RGC and the C terminal domain , aa 731 1054 , of ROS GC 1 . ^^^ Thus , the GCAP 1 and GCAP 2 signal transduction mechanisms are different , occurring through different modules of ROS GC 1 . ^^^ |
|
| Interacting proteins: Q02846 and Q9UMX6 |
Pubmed |
SVM Score :0.0 |
| The present study shows that the E786D mutation has no effect on the basal catalytic activity of ROS GC 1 and on its activation by GCAP 1 and S100beta ; however , the mutated cyclase becomes more activated by GCAP 2 . ^^^ |
|
| Interacting proteins: Q02846 and Q9UMX6 |
Pubmed |
SVM Score :0.0 |
| NA |
|
| Interacting proteins: Q02846 and Q9UMX6 |
Pubmed |
SVM Score :0.0 |
| NA |
|
| Interacting proteins: Q02846 and Q9UMX6 |
Pubmed |
SVM Score :0.0 |
| NA |
|
| Interacting proteins: Q02846 and Q9UMX6 |
Pubmed |
SVM Score :0.0 |
| NA |
|
| Interacting proteins: Q02846 and Q9UMX6 |
Pubmed |
SVM Score :0.0 |
| NA |
|
| Interacting proteins: Q02846 and Q9UMX6 |
Pubmed |
SVM Score :0.0 |
| NA |
|
| Interacting proteins: Q02846 and Q9UMX6 |
Pubmed |
SVM Score :0.0 |
| NA |
|
| Interacting proteins: Q02846 and Q9UMX6 |
Pubmed |
SVM Score :0.0 |
| NA |
|
| Interacting proteins: Q02846 and Q9UMX6 |
Pubmed |
SVM Score :0.0 |
| NA |
|
| Interacting proteins: Q9UMX6 and Q02846 |
Pubmed |
SVM Score :0.0 |
| NA |
|
| Interacting proteins: Q9UMX6 and Q02846 |
Pubmed |
SVM Score :0.0 |
| NA |
|
| Interacting proteins: Q9UMX6 and Q02846 |
Pubmed |
SVM Score :0.0 |
| NA |
|
| Interacting proteins: Q9UMX6 and Q02846 |
Pubmed |
SVM Score :0.0 |
| NA |
|
| Interacting proteins: Q9UMX6 and Q02846 |
Pubmed |
SVM Score :0.0 |
| NA |
|
| Interacting proteins: Q9UMX6 and Q02846 |
Pubmed |
SVM Score :0.0 |
| NA |
|
| Interacting proteins: Q9UMX6 and Q02846 |
Pubmed |
SVM Score :0.0 |
| NA |
|
| Interacting proteins: Q9UMX6 and Q02846 |
Pubmed |
SVM Score :0.0 |
| NA |
|
| Interacting proteins: Q9UMX6 and Q02846 |
Pubmed |
SVM Score :0.0 |
| NA |
|
| Interacting proteins: Q9UMX6 and Q02846 |
Pubmed |
SVM Score :0.0 |
| These results demonstrate that GCAP 1 is an activator of ROS GC , while the finding of a second activator , GCAP 2 , suggests that a similar mechanism of GC regulation may be present in outer segments , other subcellular compartments of the photoreceptor , or other cell types . . ^^^ |
|
| Interacting proteins: Q9UMX6 and Q02846 |
Pubmed |
SVM Score :0.0 |
| Guanylyl cyclase activating protein 2 ( GCAP 2 ) is a Ca2+ binding protein that activates RetGC 1 in a Ca2+ sensitive manner . ^^^ To establish whether GCAP 2 stimulates RetGC 1 through the ECD or ICD , we made deletion mutants lacking either the ECD or both the ECD and transmembrane domains ( TMD ) of RetGC 1 . ^^^ Recombinant wild type RetGC 1 and both deletion mutants were expressed in HEK 293 cells , and their sensitivities to GCAP 2 , Ca2+ , and ATP were compared . ^^^ Our data demonstrate that both deletion mutants are regulated similarly to wild type RetGC 1 with indistinguishable EC 50 values for Ca2+ and similar K1 / 2 values for activation by GCAP 2 . ^^^ This shows that GCAP 2 functions through the ICD of RetGC 1 and that removal of the ECD and TMD do not significantly alter regulation by these factors . ^^^ |
|
| Interacting proteins: Q9UMX6 and Q02846 |
Pubmed |
SVM Score :0.0 |
| Guanylyl cyclase activating protein 2 ( GCAP 2 ) is a recoverin like calcium binding protein that regulates photoreceptor guanylyl cyclase ( RetGC ) ( Dizhoor , A . ^^^ We found that compartmentalization of GCAP 2 in photoreceptor outer segment membranes is Ca2+ and ionic strength sensitive , but it does not require the presence of the fatty acyl group and does not necessarily directly reflect GCAP 2 interaction with RetGC . ^^^ The lack of myristoylation does not significantly affect the ability of GCAP 2 to stimulate RetGC . ^^^ Nor does it affect the ability of the Ca2+ loaded form of GCAP 2 to compete with the GCAP 2 mutant that constitutively activates RetGC . ^^^ |
|
| Interacting proteins: Q9UMX6 and Q02846 |
Pubmed |
SVM Score :0.0 |
| This cyclase shares a high sequence identity with ROS GC , is specifically expressed in the bovine retina , and , like ROS GC , is modulated in low Ca2+ by a calmodulin like Ca2+ binding protein , termed GCAP 2 . ^^^ |
|
| Interacting proteins: Q9UMX6 and Q02846 |
Pubmed |
SVM Score :0.0 |
| In the present study the GCAP 2 dependent Ca2+ modulation of the cyclase activity has been reconstituted using recombinant forms of GCAP 2 and ROS GC 1 , and its mutants . ^^^ The results indicate that consistent to phototransduction , GCAP 2 at low Ca2+ concentration ( 10 nM ) maximally stimulates the cyclase activity of the wild type and its mutants : ext ( deleted aa 8 408 ) , kin ( deleted aa 447 730 ) and hybrid consisting of the ext , transmembrane and kin domains of ANF RGC and the C terminal domain , aa 731 1054 , of ROS GC 1 . ^^^ Thus , the GCAP 1 and GCAP 2 signal transduction mechanisms are different , occurring through different modules of ROS GC 1 . ^^^ |
|
| Interacting proteins: Q9UMX6 and Q02846 |
Pubmed |
SVM Score :0.0 |
| The present study shows that : ( 1 ) GCAP 2 is a specific modulator of ROS GC 2 ; ( 2 ) through systematic remodeling of ROS GC modules , the study also shows that the modulated domain resides within the amino acid segment 736 1020 . ^^^ |
|
| Interacting proteins: Q9UMX6 and Q02846 |
Pubmed |
SVM Score :0.0 |
| Photoreceptor membrane guanylate cyclases ( RetGC ) are regulated by calcium binding proteins , GCAP 1 and GCAP 2 . ^^^ Instead , the Y104C GCAP 2 stimulates RetGC less efficiently than the wild type GCAP 2 . ^^^ |
|
| Interacting proteins: Q9UMX6 and Q02846 |
Pubmed |
SVM Score :0.0 |
| RetGC 1 and RetGC 2 are photoreceptor membrane guanylyl cyclases that are regulated by the Ca2+ binding protein , GCAP 2 . ^^^ We used a protease protection assay to localize regions of the intracellular domains of RetGCs important for the interaction with GCAP 2 and found that GCAP 2 reduces the access of trypsin to a site in the kinase homology domain ( KHD ) of RetGC 1 . ^^^ We also found that RetGC 2 and GCAP 2 interact cooperatively with high affinity , but RetGC 1 and GCAP 2 interact noncooperatively with low affinity . ^^^ By analyzing RetGC 1 / RetGC 2 chimeras we demonstrated that the affinity and cooperativity of the interaction with GCAP 2 is dictated by the structure of the KHD . ^^^ These findings suggest that GCAP 2 interacts constituitively with the KHDs of RetGC 1 and RetGC 2 and that cGMP synthesis is controlled by Ca2+ dependent conformational changes in the RetGC / GCAP complex . . ^^^ |
|
| Interacting proteins: Q9UMX6 and Q02846 |
Pubmed |
SVM Score :0.0 |
| The present study shows that the E786D mutation has no effect on the basal catalytic activity of ROS GC 1 and on its activation by GCAP 1 and S100beta ; however , the mutated cyclase becomes more activated by GCAP 2 . ^^^ |
|
| Interacting proteins: Q9UMX6 and Q02846 |
Pubmed |
SVM Score :0.0 |
| The photoreceptor membrane guanylyl cyclases , RetGC 1 and RetGC 2 ( also referred to as GC E and GC F ) , are regulated intracellularly by two Ca ( 2+ ) binding proteins , GCAP 1 and GCAP 2 . ^^^ |
|
| Interacting proteins: Q9UMX6 and Q02846 |
Pubmed |
SVM Score :0.0 |
| The other GCAP protein , GCAP 2 , which is also a known modulator of ROS GC in photoreceptors , was not present in the pineal gland . ^^^ |
|
| Interacting proteins: Q9UMX6 and Q02846 |
Pubmed |
SVM Score :0.0 |
| Point mutations within the EF 1 region can interfere with both the activation of the cyclase by the Ca ( 2+ ) free form of GCAP 2 and the inhibition of retGC basal activity by the Ca ( 2+ ) loaded GCAP 2 . ^^^ |
|
| Interacting proteins: Q9UMX6 and Q02846 |
Pubmed |
SVM Score :0.0 |
| GCAP 1 and GCAP 2 regulated ROS GC 1 activities differently . ^^^ |
|
| Interacting proteins: Q9UMX6 and Q02846 |
Pubmed |
SVM Score :0.0 |
| GCAP 2 activates RetGC at free Ca2+ concentrations below 100 nM , characteristic of light adapted photoreceptors , and inhibits RetGC when free Ca2+ concentrations are above the 500 nM level , characteristic of dark adapted photoreceptors . ^^^ We have mapped functional domains in GCAP 2 by using deletion mutants and chimeric proteins in which parts of GCAP 2 were substituted with corresponding fragments of other closely related recoverin like proteins that do not regulate RetGC . ^^^ We find that in addition to the EF hand Ca2+ binding centers there are three regions that contain GCAP 2 specific sequences essential for regulation of RetGC . 1 ) The region between Phe 78 and Asp 113 determines whether GCAP 2 activates outer segment RetGC in low or high Ca2+ concentrations . ^^^ They activate RetGC only at high and not at low Ca2+ concentrations . 2 ) The amino acid sequence of GCAP 2 between Lys 29 and Phe 48 that includes the EF hand related motif EF 1 is essential both for activation of RetGC at low Ca2+ and inhibition at high Ca2+ concentrations . ^^^ Most of the remaining N terminal region can be substituted with recoverin or neurocalcin sequences without loss of GCAP 2 function . 3 ) Region Val 171 Asn189 , adjacent to the C terminal EF 4 contributes to activation of RetGC , but it is not essential for the ability of Ca2+ loaded GCAP 2 to inhibit RetGC . ^^^ |
|
| Interacting proteins: Q9UMX6 and Q02846 |
Pubmed |
SVM Score :0.0 |
| It reduces the overall catalytic ability of RetGC 1 and dramatically reduces stimulation by GCAP 2 , although GCAP 2 still appears to interact with the protein . ^^^ |
|
| Interacting proteins: Q9UMX6 and Q02846 |
Pubmed |
SVM Score :0.0 |
| The ability of GCAP 2 and its several mutants to activate retGC in vitro correlates with their ability to dimerize at low free Ca ( 2+ ) concentrations . ^^^ A constitutively active GCAP 2 mutant E80Q / E116Q / D158N that stimulates retGC regardless of the free Ca ( 2+ ) concentrations forms dimers both in the absence and in the presence of Ca ( 2+ ) . ^^^ Several GCAP 2 / neurocalcin chimera proteins that can not efficiently activate retGC in low Ca ( 2+ ) concentrations are also unable to dimerize in the absence of Ca ( 2+ ) . ^^^ |
|
| Interacting proteins: Q9UMX6 and Q02846 |
Pubmed |
SVM Score :0.0 |
| Functionally therefore , the retGC 2 and GCAP 2 mutations are similar in reducing the feedback inhibition of Ca2+ on cyclase activity and thereby on cGMP levels in the photoreceptors . . ^^^ |
|
| Interacting proteins: Q9UMX6 and Q02846 |
Pubmed |
SVM Score :0.0 |
| Inactivation of the CNDPK phosphorylation site in GCAP 2 by substitutions S201G or S201D , as well as phosphorylation or thiophosphorylation of Ser ( 201 ) , had little effect on the ability of GCAP 2 to regulate retGC in reconstituted membranes in vitro . ^^^ |
|
| Interacting proteins: Q9UMX6 and Q02846 |
Pubmed |
SVM Score :0.0 |
| This study maps the GCAP 2 modulatory site in ROS GC 1 through the use of multiple techniques involving surface plasmon resonance binding studies with soluble ROS GC 1 constructs , coimmunoprecipitation , functional reconstitution experiments with deletion mutants , and peptide competition assays . ^^^ The findings show that the sequence motif of the core GCAP 2 modulatory site is Y 965 N981 of ROS GC 1 . ^^^ |
|
| Interacting proteins: Q9UMX6 and Q02846 |
Pubmed |
SVM Score :0.0 |
| When photoreceptor outer segment homogenates are preincubated with AMP PNP ( EC 50 = 0 . 65 + / 0 . 20 mM ) , GCAP 2 enhanced the retGC activity 10 13 times over the control rate . ^^^ The large activation is due to a GCAP 2 dependent increase in Vmax without an alteration of retGC affinity for GCAP 2 ( EC 50 = 47 . 9 + / 2 . 7 nM ) . ^^^ |
|
| Interacting proteins: Q9UMX6 and Q02846 |
Pubmed |
SVM Score :0.0 |
| In rod phototransduction , cyclic GMP synthesis by membrane bound guanylate cyclase ROS GC 1 is under Ca ( 2+ ) dependent negative feedback control mediated by guanylate cyclase activating proteins , GCAP 1 and GCAP 2 . ^^^ The cellular concentration of GCAP 1 and GCAP 2 approximately sums to the cellular concentration of a functional ROS GC 1 dimer . ^^^ However , the presence of a myristoyl group in GCAP 1 has a strong impact on the regulation of ROS GC 1 , this is in contrast to GCAP 2 . ^^^ The findings show that differences in catalytic efficiency and Ca ( 2+ ) sensitivity of ROS GC 1 are conferred by GCAP 1 and GCAP 2 . ^^^ |
|