The product of this gene belongs to a subfamily of calcium binding proteins, which share similarity to calmodulin. Calcium binding proteins are an important component of calcium mediated cellular signal transduction. Expression of this gene was only detected in retina and brain. Study of the mouse homolog demonstrated that groups of cells expressing this protein are located in the center or inner border of the inner unclear layer of retina. Three alternatively spliced variants encoding different isoforms have been described. [provided by RefSeq, Jul 2008].
Function: Modulates calcium-dependent activity of inositol 1,4,5-triphosphate receptors (ITPRs). Inhibits agonist-induced intracellular calcium signaling. Enhances inactivation and does not support calcium-dependent facilitation of voltage-dependent P/Q-type calcium channels. Causes calcium-dependent facilitation and inhibits inactivation of L-type calcium channels by binding to the same sites as calmodulin in the C-terminal domain of CACNA1C, but resulting in an opposit effects on channel function. Suppresses the calcium-dependent inactivation of CACNA1D (By similarity). Inhibits TRPC5 channels. Prevents NMDA receptor-induced cellular degeneration (By similarity).