Structural insights for activation of retinal guanylate cyclase by GCAP1.

ABSTRACT: Guanylyl cyclase activating protein 1 (GCAP1), a member of the neuronal calcium sensor (NCS) subclass of the calmodulin superfamily, confers Ca(2+)-sensitive activation of retinal guanylyl cyclase 1 (RetGC1) upon light activation of photoreceptor cells. Here we present NMR assignments and functional analysis to probe Ca(2+)-dependent structural changes in GCAP1 that control activation of RetGC. NMR assignments were obtained for both the Ca(2+)-saturated inhibitory state of GCAP1 versus a GCAP1 mutant (D144N/D148G, called EF4mut), which lacks Ca(2+) binding in EF-hand 4 and models the Ca(2+)-free/Mg(2+)-bound activator state of GCAP1. NMR chemical shifts of backbone resonances for Ca(2+)-saturated wild type GCAP1 are overall similar to those of EF4mut, suggesting a similar main chain struct

SUBMITTER: Lim S 

PROVIDER: S-EPMC3827477 | biostudies-literature | 2013

REPOSITORIES: biostudies-literature