As sperm encounter the more alkaline environment of the female reproductive tract, CatSper channels become activated by the altered ion concentration.
[1] The study of these channels has been slow because they do not traffic to the cell membrane in many heterologous systems.
[3] Progesterone binds to the protein ABHD2 which is present in the sperm plasma membrane, which causes ABHD2 to cleave an inhibitor of CatSper (2-arachidonoylglycerol) into arachidonic acid and glycerol.
[5] CatSper plays a key role in mediating hyperactive motility – prior to fertilization, sperm become entrapped within the fingerlike projections of the microvilli of the oviduct.
Catsper1 plays an important role in evoked Ca2+ entry and regulation of hyperactivation in sperm.