Mediates sodium- and chloride-dependent transport of taurine (PubMed:1465453, PubMed:9375654, PubMed:30270321). Can also mediate transport of hypotaurine, beta-alanine and gamma-aminobutyric acid (GABA) (PubMed:1465453, PubMed:9375654, PubMed:30270321). 4-aminobutanoate(out) + chloride(out) + 2 Na(+)(out) = 4-aminobutanoate(in) + chloride(in) + 2 Na(+)(in) chloride(out) + 2 Na(+)(out) + taurine(out) = chloride(in) + 2 Na(+)(in) + taurine(in) beta-alanine(out) + chloride(out) + 2 Na(+)(out) = beta-alanine(in) + chloride(in) + 2 Na(+)(in) chloride(out) + hypotaurine(out) + 2 Na(+)(out) = chloride(in) + hypotaurine(in) + 2 Na(+)(in) Taurine tranport activity is inhibited by phorbol 12-myristate 13-acetate, 3-guanidinopropionic acid, L-2,3- diaminopropionic acid, beta-alanine and hypotaurine. Optimum pH is 7.5-8.0 (for taurine transport). Widely expressed (PubMed:1465453, PubMed:22896705). Highly expressed in the ciliary body of the eye (PubMed:9375654). Taurine transport activity is down-regulated upon Ser-322 phosphorylation. Belongs to the sodium:neurotransmitter symporter (SNF) (TC 2.A.22) family. SLC6A6 subfamily.