Cloning of the human taurine transporter and characterization of taurine uptake in thyroid cells

Abstract

A cDNA clone encoding a taurine transporter, designated HTAU, has been isolated from human thyroid. It contains an open reading frame encoding a protein of 619 amino acids with a calculated molecular weight of 69,675 Da. The predicted amino acid sequence of HTAU is highly homologous to those of dog kidney and rat brain. The HTAU mRNA was detectable in various human tissues examined. Transient expression of HTAU in COS-7 cells conferred a higher taurine uptake. The taurine uptake in FRTL-5 cells appears to be regulated by thyrotropin through cAMP. Finally, a higher taurine uptake may be associated with a higher proliferation rate in some cultured cell lines.