L-Type Amino Acid Transporter 1 (y+LAT1)

The SLC7A7 gene encodes the light subunit of a cationic amino acid transporter. Together with the heavy chain, 4F2hc (SLC3A2), the SLC7A7 protein forms a functional heterodimeric transporter on the basolateral cell membrane of epithelial cells that transfers lysine, arginine, and ornithine from the cell to the extracellular space The SLC7A7 gene encodes a deduced 511-residue protein with a molecular mass of 56 kD that contains 12 transmembrane domains. The protein sequence shows 81% homology to the opossum protein. Northern blot analysis identified a 2.4-kb mRNA transcript expressed in kidney, peripheral blood leukocytes, lung, placenta, spleen, and small intestine. SLC7A7 associated with SLC3A2 to form a functional 135-kD heterodimer linked by a disulfide bridge involving cysteine 109 of SLC3A2.