CatSper3, is aproteinwhich in humans is encoded by theCATSPER3gene. CatSper3 is a member of thecation channels of spermfamily of proteins. The four proteins in this family together form aCa2+-permeantion channelspecific essential for the correct function of sperm cells. Voltage-gated calcium channel that plays a central role in calcium-dependent physiological responses essential for successful fertilization, such as sperm hyperactivation, acrosome reaction and chemotaxis towards the oocyte.