Cation Channel, Sperm Associated Beta (CATSPERb)

Using a transgenic approach to identify proteins associated with the CatSper complex, Liu et al. (2007) purified a CatSper1 complex from mouse testis that contained HSP70-2 (HSPA1B) and a previously uncharacterized protein, which the authors designated CatSper-beta. By database searching and RT-PCR, Liu et al. (2007) a full-length mouse CatSper-beta cDNA encoding a deduced 1,109-amino acid protein with at least 2 transmembrane domains and 8 N-glycosylation sites. By database analysis, Liu et al. (2007) identified a human homolog encoding a deduced 1,116 amino acids that shared approximately 56% sequence identity with the mouse protein. Like the CatSper ion channel subunits, mouse CatSper-beta expression was restricted to testis and localized to the principal piece of the sperm tail.