Description
Product Characteristics:
intracellular stimulation of guanylate cyclase (GC) by calcium, a key event in the recovery of the dark state of rod photoreceptors after exposure to light, is mediated by guanylate cyclase-activating protein (GCAP1). GCAPs are calcium-The binding proteins belonging to the calmodulin superfamily. GCAP1 is a calcium-binding protein that stimulates synthesis of c-GMP in photoreceptors. GCAP1 is present in rod and cone photoreceptor outer segments where phototransduction occurs. In contrast to other calcium-binding proteins from the calmodulin superfamily, the calcium-free form of GCAP1 stimulates the effector enzyme. By molecular cloning of human and mouse GCAP cDNA, the known mammalian GCAPs are found to be more than 90 % similar, consisting of 201 to 205 amino acids, and containing three identically conserved calcium-binding sites. A related protein, GCAP2, is detectable only in the retina and results from a gene duplication event.
Subcellular location: Cell membrane
Synonyms: COD3, GCAP 1, GCAP, Guanylate Cyclase Activating Protein Photoreceptor 1, Guanylate Cyclase Activating Protein Photoreceptor 1, Guanylate Cyclase Activator 1A, Guanylate Cyclase Activator 1A, Guanylin 1, Guanylin 1, guanylyl cyclase activating protein 1, Guanylyl cyclase-activating protein 1, GUC1A_HUMAN, GUCA, GUCA1, GUCA1A, GUCA1A.
Target Information: This gene plays a role in the recovery of retinal photoreceptors from photobleaching. In the recovery phase, the phototransduction messeneger cGMP is replenished by retinal guanylyl cyclase-1 (GC1). GC1 is activated by decreasing Ca(2+) concentrations following photobleaching. The protein encoded by this gene, guanylyl cyclase activating protein 1 (GCAP1), mediates the sensitivity of GC1 to Ca(2+) concentrations. GCAP1 promotes activity of GC1 at low Ca(2+) concentrations and inhibits GC1 activity at high Ca(2+) concentrations. Mutations in this gene cause autosomal dominant cone dystrophy (COD3)\, a disease characterized by reduced visual acuity associated with progressive loss of color vision. Mutations in this gene prohibit the inactivation of RetGC1 at high Ca(2+) concentrations\, causing the constitutive activation of RetGC1 and, presumably, increased cell death. This gene is expressed in retina and spermatagonia. [provided by RefSeq, Feb 2009]