CatSper2, is a protein which in humans is encoded by the CATSPER2 gene. CatSper2 is a member of the cation channels of sperm family of protein. The four proteins in this family together form a Ca²⁺-permeant ion channel specific essential for the correct function of sperm cells.

Calcium ions play a primary role in the regulation of sperm motility. This gene belongs to a family of putative cation channels that are specific to spermatozoa and localize to the flagellum. The protein family features a single repeat with six membrane-spanning segments and a predicted calcium-selective pore region. This gene is part of a tandem repeat on chromosome 15q15; the second copy of this gene is thought to be a pseudogene.

This article incorporates text from the United States National Library of Medicine, which is in the public domain.