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Dimerization of Neuronal Calcium Sensor Proteins.

Dimerization of Neuronal Calcium Sensor Proteins.

Authors :
Ames JB
Source :
Frontiers in molecular neuroscience [Front Mol Neurosci] 2018 Nov 02; Vol. 11, pp. 397. Date of Electronic Publication: 2018 Nov 02 (Print Publication: 2018).
Publication Year :
2018

Abstract

Neuronal calcium sensor (NCS) proteins are EF-hand containing Ca <superscript>2+</superscript> binding proteins that regulate sensory signal transduction. Many NCS proteins (recoverin, GCAPs, neurocalcin and visinin-like protein 1 (VILIP1)) form functional dimers under physiological conditions. The dimeric NCS proteins have similar amino acid sequences (50% homology) but each bind to and regulate very different physiological targets. Retinal recoverin binds to rhodopsin kinase and promotes Ca <superscript>2+</superscript> -dependent desensitization of light-excited rhodopsin during visual phototransduction. The guanylyl cyclase activating proteins (GCAP1-5) each bind and activate retinal guanylyl cyclases (RetGCs) in light-adapted photoreceptors. VILIP1 binds to membrane targets that modulate neuronal secretion. Here, I review atomic-level structures of dimeric forms of recoverin, GCAPs and VILIP1. The distinct dimeric structures in each case suggest that NCS dimerization may play a role in modulating specific target recognition. The dimerization of recoverin and VILIP1 is Ca <superscript>2+</superscript> -dependent and enhances their membrane-targeting Ca <superscript>2+</superscript> -myristoyl switch function. The dimerization of GCAP1 and GCAP2 facilitate their binding to dimeric RetGCs and may allosterically control the Ca <superscript>2+</superscript> -dependent activation of RetGCs.

Details

Language :
English
ISSN :
1662-5099
Volume :
11
Database :
MEDLINE
Journal :
Frontiers in molecular neuroscience
Publication Type :
Academic Journal
Accession number :
30450035
Full Text :
https://doi.org/10.3389/fnmol.2018.00397