Guanylyl cyclase-activating proteins (GCAPs) are Ca2+/Mg2+ sensors: implications for photoreceptor guanylyl cyclase (RetGC) regulation in mammalian photoreceptors.
AuthorsPeshenko IV, Dizhoor AM
JournalJ Biol Chem
PubMed ID14993224
'Guanylyl cyclase-activating proteins (GCAP) are EF-hand Ca(2+)-binding proteins that activate photoreceptor guanylyl cyclase (RetGC) in the absence of Ca(2+) and inhibit RetGC in a Ca(2+)-sensitive manner. The reported data for the RetGC inhibition by Ca(2+)/GCAPs in vitro are in disagreement with the free Ca(2+) levels found in mammalian photoreceptors (Woodruff, ... More