The
cation channels of sperm also known as
Catsper channels or
CatSper, are
ion channels that are related to the
two-pore channels and distantly related to
TRP channels. The four members of this family form
voltage-gated Ca
2+ channels that seem to be specific to sperm. As sperm encounter the more alkaline environment of the female reproductive tract, CatSper channels become activated by the altered ion concentration. These channels are required for proper fertilization. The study of these channels has been slow because they do not traffic to the
cell membrane in many
heterologous systems.