ABCG5 Gene - ATP Binding Cassette Subfamily G Member 5 | Function, Mutations & Diseases

ABCG5 encodes a member of the ATP-binding cassette (ABC) transporter superfamily, specifically the white subfamily. The protein forms a heterodimer with ABCG8 to function as a sterol efflux transporter in the liver and intestine, limiting intestinal absorption and promoting biliary excretion of plant sterols and cholesterol. Mutations in ABCG5 cause sitosterolemia, a rare autosomal recessive disorder characterized by hyperabsorption and impaired elimination of sterols, leading to premature atherosclerosis and xanthomas.

Tissue Expression

Cell Line Expression

Hotspot Mutations

Mutation functional classification

• Sterol regulatory element-binding protein (SREBP) signaling

• Bile secretion (KEGG: hsa04976)

• ABC transporters (KEGG: hsa02010)

• Cholesterol metabolism (Reactome: R-HSA-191273)

ABCG5 (sterolin-1) is a 651-amino acid transmembrane protein that heterodimerizes with ABCG8 to form the sterol efflux transporter. It localizes to the apical membrane of hepatocytes and enterocytes, mediating the export of cholesterol and plant sterols into bile and intestinal lumen. The protein contains an N-terminal transmembrane domain and a C-terminal nucleotide-binding domain (NBD) that binds ATP to drive transport. Defects in ABCG5 disrupt sterol homeostasis, leading to sitosterolemia.