Interaction Of GCAP1 With Retinal Guanylyl Cyclase And Calcium: Sensitivity to Fatty Acylation
Guanylyl cyclase activating proteins (GCAP)1 are calcium/magnesium binding proteins within neuronal calcium sensor proteins group (NCS) of the EF-hand proteins superfamily. GCAPs activate retinal guanylyl cyclase (RetGC) in vertebrate photoreceptors in response to light-dependent fall of the intrace...
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2012-02-01
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| Series: | Frontiers in Molecular Neuroscience |
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| Online Access: | http://journal.frontiersin.org/Journal/10.3389/fnmol.2012.00019/full |
| _version_ | 1811344810809753600 |
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| author | Igor V. Peshenko Elena V. Olshevskaya Alexander M. Dizhoor |
| author_facet | Igor V. Peshenko Elena V. Olshevskaya Alexander M. Dizhoor |
| author_sort | Igor V. Peshenko |
| collection | DOAJ |
| description | Guanylyl cyclase activating proteins (GCAP)1 are calcium/magnesium binding proteins within neuronal calcium sensor proteins group (NCS) of the EF-hand proteins superfamily. GCAPs activate retinal guanylyl cyclase (RetGC) in vertebrate photoreceptors in response to light-dependent fall of the intracellular free Ca2+ concentrations. GCAPs consist of four EF-hand domains and contain N-terminal fatty acylated glycine, which in GCAP1 is required for the normal activation of RetGC. We analyzed the effects of a substitution prohibiting N-myristoylation (Gly2 → Ala) on the ability of the recombinant GCAP1 to co-localize with its target enzyme when heterologously expressed in HEK293 cells. We also compared Ca2+ binding and RetGC-activating properties of the purified non-acylated G2A mutant and C14:0 acylated GCAP1 in vitro. The G2A GCAP1 expressed with a C-terminal GFP tag was able to co-localize with the cyclase, albeit less efficiently than the wild type, but much less effectively stimulated cyclase activity in vitro. Ca2+ binding isotherm of the G2A GCAP1 was slightly shifted toward higher free Ca2+ concentrations and so was Ca2+ sensitivity of RetGC reconstituted with the non-acylated mutant. At the same time, myristoylation had little effect on the high-affinity Ca2+-binding in the EF-hand that is proximal to the myristoyl residue in the three-dimensional GCAP1 structure. These data indicate that the N-terminal fatty acyl group may alter the activity of EF-hands in the distal portion of the GCAP1 molecule via presently unknown intramolecular mechanism. |
| first_indexed | 2024-04-13T19:53:39Z |
| format | Article |
| id | doaj.art-403994875e3345669362809e02f6986d |
| institution | Directory Open Access Journal |
| issn | 1662-5099 |
| language | English |
| last_indexed | 2024-04-13T19:53:39Z |
| publishDate | 2012-02-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Molecular Neuroscience |
| spelling | doaj.art-403994875e3345669362809e02f6986d2022-12-22T02:32:25ZengFrontiers Media S.A.Frontiers in Molecular Neuroscience1662-50992012-02-01510.3389/fnmol.2012.0001921991Interaction Of GCAP1 With Retinal Guanylyl Cyclase And Calcium: Sensitivity to Fatty AcylationIgor V. Peshenko0Elena V. Olshevskaya1Alexander M. Dizhoor2Salus UniversitySalus UniversitySalus UniversityGuanylyl cyclase activating proteins (GCAP)1 are calcium/magnesium binding proteins within neuronal calcium sensor proteins group (NCS) of the EF-hand proteins superfamily. GCAPs activate retinal guanylyl cyclase (RetGC) in vertebrate photoreceptors in response to light-dependent fall of the intracellular free Ca2+ concentrations. GCAPs consist of four EF-hand domains and contain N-terminal fatty acylated glycine, which in GCAP1 is required for the normal activation of RetGC. We analyzed the effects of a substitution prohibiting N-myristoylation (Gly2 → Ala) on the ability of the recombinant GCAP1 to co-localize with its target enzyme when heterologously expressed in HEK293 cells. We also compared Ca2+ binding and RetGC-activating properties of the purified non-acylated G2A mutant and C14:0 acylated GCAP1 in vitro. The G2A GCAP1 expressed with a C-terminal GFP tag was able to co-localize with the cyclase, albeit less efficiently than the wild type, but much less effectively stimulated cyclase activity in vitro. Ca2+ binding isotherm of the G2A GCAP1 was slightly shifted toward higher free Ca2+ concentrations and so was Ca2+ sensitivity of RetGC reconstituted with the non-acylated mutant. At the same time, myristoylation had little effect on the high-affinity Ca2+-binding in the EF-hand that is proximal to the myristoyl residue in the three-dimensional GCAP1 structure. These data indicate that the N-terminal fatty acyl group may alter the activity of EF-hands in the distal portion of the GCAP1 molecule via presently unknown intramolecular mechanism.http://journal.frontiersin.org/Journal/10.3389/fnmol.2012.00019/fullCalciumphotoreceptorsguanylyl cyclasemyristoylation |
| spellingShingle | Igor V. Peshenko Elena V. Olshevskaya Alexander M. Dizhoor Interaction Of GCAP1 With Retinal Guanylyl Cyclase And Calcium: Sensitivity to Fatty Acylation Frontiers in Molecular Neuroscience Calcium photoreceptors guanylyl cyclase myristoylation |
| title | Interaction Of GCAP1 With Retinal Guanylyl Cyclase And Calcium: Sensitivity to Fatty Acylation |
| title_full | Interaction Of GCAP1 With Retinal Guanylyl Cyclase And Calcium: Sensitivity to Fatty Acylation |
| title_fullStr | Interaction Of GCAP1 With Retinal Guanylyl Cyclase And Calcium: Sensitivity to Fatty Acylation |
| title_full_unstemmed | Interaction Of GCAP1 With Retinal Guanylyl Cyclase And Calcium: Sensitivity to Fatty Acylation |
| title_short | Interaction Of GCAP1 With Retinal Guanylyl Cyclase And Calcium: Sensitivity to Fatty Acylation |
| title_sort | interaction of gcap1 with retinal guanylyl cyclase and calcium sensitivity to fatty acylation |
| topic | Calcium photoreceptors guanylyl cyclase myristoylation |
| url | http://journal.frontiersin.org/Journal/10.3389/fnmol.2012.00019/full |
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