Ca(2+)-binding protein that may be involved in basal body assembly or in a subsequent step of ciliogenesis. Interacts with G-protein beta-gamma dimers in a calcium-dependent manner. Accumulates at procentrioles during their elongation. Isoform 3 is not observed in the centriole. In brain, specifically expressed in ciliated cells. In retina, expression is localized to the connecting cilium and basal body of photoreceptors (at protein level). Highly expressed in brain, kidney, lung, retina and ovary, and weakly expressed in spleen. Not detected in testis, colon, stomach, thymus, skeletal muscle, heart, intestine or liver. The fourth EF-hand domain has been proven to bind calcium. Phosphorylated on Thr-134 by casein kinase II (CK2) in a light-dependent manner. Belongs to the centrin family.