. "Heterotetramer; possibly composed of CATSPER1, CATSPER2, CATSPER3 and CATSPER4 (Potential). Component of the CatSper complex. Interacts with CATSPER3 and CATSPER4 (By similarity). Interacts with Ca(v)3.3/CACNA1I, leading to suppress T-type calcium channel activity." .