Plays a fundamental role in microtubule-organizing center structure and function (PubMed:8175926). Plays a role in sperm cilia formation (By similarity). Monomer (By similarity). Interacts with PIFO (PubMed:20643351). Centrosome of interphase and mitotic cells. In the retinal photoreceptor cells, localizes at the connecting cilium, a thin bridge linking the cell body and the light-sensing outer segment (By similarity). Binds two moles of calcium per mole of protein. Belongs to the centrin family.