SLC3A1

SLC3A1 encodes rBAT, a heavily glycosylated type II membrane protein that is expressed chiefly at the apical brush border of kidney proximal-tubule and intestinal epithelial cells. rBAT forms a disulfide-linked heterodimer with the SLC7A9 light chain and promotes assembly, maturation, oligomerization, and delivery of the heteromeric amino-acid transporter to the cell surface. The SLC7 light chain supplies the transmembrane transport pathway, whereas SLC3A1 is the heavy-chain accessory and trafficking subunit. The resulting complex supports renal and intestinal reabsorption of cystine and dibasic amino acids; loss-of-function SLC3A1 variants cause cystinuria, with poorly soluble urinary cystine producing recurrent stones. The extracellular alpha-amylase-like fold is structurally important but lacks demonstrated glucosidase activity.

Disorders

Relationship is the entry's genetic[].relationship_type. untyped means the entry has a genetic record for the gene but does not type it; its free-text association is shown instead.

An entry matches when ClinGen's MONDO disease is the entry's own disease term, a subtype term, or an exact-match mapping. An amber status marks an entry ClinGen supports the gene for (Definitive, Strong or Moderate) whose own record does not type it. A Limited, Disputed or Refuted tier on such an entry is not a gap.