Acts as a DIDS-sensitive anion exchanger mediating chloride, sulfate and oxalate transport. May fulfill critical anion exchange functions in male germ line during meiosis and hence may play a role in spermatogenesis. May be involved in a new regulatory pathway linking sulfate transport to RhoGTPase signaling in male germ cells. A critical component of the sperm annulus that is essential for correct sperm tail differentiation and motility and hence male fertility. May form a molecular complex involved in the regulation of chloride and bicarbonate ions fluxes during sperm capacitation (By similarity). Interacts with RACGAP1. Interacts with CFTR. Located at the annulus ring structure within the sperm cell. Expressed in testis and epididymis. Located at the end of the midpiece of the flagella, known as the annulus, in spermatozoa. N-glycosylated. Sperm lacks motility and displayed a capacitation defect, with reduced cAMP concentration due to misactivation of soluble adenylate cyclase (see Adcy1). Due to a partial intron retention. Belongs to the SLC26A/SulP transporter (TC 2.A.53) family.