Mammalian cysteine-rich secretory proteins interact with plasma membrane Ca exporter PMCA4b.

Background: Mammalian cysteine-rich secretory proteins (CRISPs) are predominantly expressed in the male reproductive tract. Knockout mice lacking two or more CRISPs show defects in sperm transport, sperm-egg interaction and Ca homeostasis. CRISPs play redundant and specific roles via their binding partners.