In mammals, L-ascorbic acid (vitamin C) enters cells via Na+-dependent transporters SVCT1 (solute carrier family 23 member 1, SLC23A1) and SVCT2 (solute carrier family 23 member 1, SLC23A2). Both proteins are predicted to contain 12 potential transmembrane (TM) domains with N- and C-termini on the cytoplasmic side of the membrane. Both isoforms have Na+:ascorbic acid stoichiometry of 2:1. SVCT2 may exhibit a higher affinity for ascorbic acid than SVCT1, but with a lower maximum velocity. SVCT1 is present in epithelial tissues, whereas SVCT2 is present in most tissues with the exception of lung and skeletal muscle []. SVCT1 is involved in whole-body homeostasis of vitamin C, while SVCT2 protects metabolically active cells against oxidative stress [].This entry represents SVCT1 (SLC23A1) [, ].
