Large Neutral Amino Acid Transporter 2 (LAT2)

SLC7A8 shares 50%, 45%, and 44% amino acid sequence identity with human LAT1, y(+)LAT2, and y(+)LAT1, respectively. Recombinant SLC7A8 expressed alone in Xenopus oocytes was intracellularly located and did not induce amino acid transport. Coexpression of SLC7A8 with the 4F2 heavy chain brought SLC7A8 to the plasma membrane and induced an amino acid transport activity that was sodium-independent and showed broad specificity for small and large zwitterionic amino acids. This activity was highly trans-stimulated, suggesting an exchanger mechanism of transport. Northern blot analysis using an SLC7A8 probe detected approximately 3.7- and 5-kb transcripts in several human tissues, with the highest expression in kidney.