Uniporter that mediates the transport of the stereospecific L-phenylalanine, L-methionine and L-branched-chain amino acids, between the extracellular space and the cytoplasm and may control the transepithelial (re)absorption of neutral amino acid in kidney and small intestine (, ). The transport activity is mediated through facilitated diffusion and is sodium ions-, chloride ions- and pH-independent .
Subcellular locations: Cell membrane, Basolateral cell membrane
Located at the basolateral membrane in the small intestine enterocytes, kidney proximal tubule, thick ascending limb and, to a minor extent, of distal convoluted tubule epithelial cells.
Detected in several tissues with higher expression in placenta, kidney and peripheral blood leukocytes . In the kidney, is detected in epithelial cells of the distal tubule and collecting duct . In the intestine, is expressed mainly in crypt cells of the intestinal microvilli and epithelial cells in the base of the villus .