Solute carrier family 7 member 13 (SLC7A13) (SLC7A13)

Solute carrier family 7 member 13, also known as SLC7A13, AGT1, or XAT2, is a member of the heterodimeric amino acid transporter family. It functions as a membrane-spanning, multi-pass transmembrane protein that primarily localizes to the apical plasma membrane of the renal proximal tubule epithelium[1][5]. SLC7A13 associates with SLC3A1 (rBAT) to form a functional heterodimer, enabling sodium-independent transport of anionic amino acids (notably L-aspartate and L-glutamate) as well as neutral amino acids and cystine, which it may preferentially reabsorb in the late proximal tubules in exchange for cytosolic glutamate or aspartate[1][3]. SLC7A13 is especially expressed in the distal portion of the proximal tubule (S3 segment), where it likely functions as the "missing partner" of rBAT for cystine reabsorption, solving a long-standing paradox in renal cystine transport physiology[3]. In addition to its role in amino acid uptake, SLC7A13 has been implicated in certain genetic disorders, including mitochondrial and neurological diseases, and may contribute to a form of cystinuria distinct from that caused by mutations in the more widely known cystine transporter b0,+AT/SLC7A9[1][3]. While SLC7A13 is a transporter and thus a potential pharmacological target, no known therapeutic drugs or modulators have been reported. Its precise physiological and pathological significance, especially in human disease, remains an active area of research. The gene is located at chromosome 8q21.3, and its orthologs are present in several mammalian species[2].

Other names

AGT1XAT2AGT-1Sodium-independent aspartate/glutamate transporter 1X-amino acid transporter 2amino acid transporter XAT2solute carrier family 7 (anionic amino acid transporter) member 13