Function
Auxiliary component of the CatSper complex, a complex involved in sperm cell hyperactivation (PubMed:28226241, PubMed:31056283). Sperm cell hyperactivation is needed for sperm motility which is essential late in the preparation of sperm for fertilization (PubMed:28226241, PubMed:31056283). Required for a distribution of the CatSper complex in linear quadrilateral nanodomains along the flagellum, maximizing fertilization inside the mammalian female reproductive tract (PubMed:28226241). Together with EFCAB9, associates with the CatSper channel pore and is required for the two-row structure of each single CatSper channel (PubMed:31056283).