Cation channel sperm-associated protein complex (CatSper)

The Cation channel sperm-associated protein complex, commonly known as the CatSper complex, is a sperm-specific, multicomponent calcium channel essential for male fertility. It is a complex network of proteins consisting of four pore-forming subunits (CatSper1-4) and several auxiliary subunits (CatSperB, CatSperG, CatSperD, CatSperE, CatSperZ, and CatSperT) localized to the principal piece of the sperm flagellum. This channel mediates the influx of calcium ions in response to alkaline pH and progesterone, which is a critical requirement for sperm hyperactivation—a specialized form of motility necessary for the sperm to penetrate the egg's protective layers. Because of its essential role in fertilization and its highly restricted expression in the testis, the CatSper complex is a primary target for the development of non-hormonal male contraceptives. Research into CatSper inhibitors aims to provide a reversible method of male birth control by preventing the calcium signaling necessary for successful fertilization.

Other names

CatSper channel complexCatSpermasomeCation channel sperm-associated protein networkSperm calcium channel complex

Inhibition of calcium influx into the sperm flagellum, preventing hyperactivation and fertilization.