Solute Carrier Family 38, Member 4 (SLC38A4)

SLC38A4 is found predominantly in liver and transports both cationic and neutral amino acids. The transport of cationic amino acids by SLC38A4 is Na(+) and pH independent, while the transport of neutral amino acids is Na(+) and pH dependent . The deduced 547-amino acid protein contains 10 putative transmembrane domains and lacks a signal peptide. NAT3 and mouse Nat share 55% amino acid identity. Northern blot analysis of hepatoma and breast carcinoma cell lines detected a 4.0-kb transcript. RT-PCR detected high expression of NAT3 in adult and embryonic liver, with lower levels in muscle, kidney, and pancreas, and trace amounts in placenta and heart. NAT3 transfected into Xenopus oocytes was expressed at the plasma membrane.