ATP-binding cassette sub-family G member 5
Domain
The Walker motif (consensus sequence G-X-X-G-X-G-K-[ST]-T) is expected to bind ATP. Within this motif, the conserved Lys is essential for transport activity mediated by the heterodimer with ABCG8.
Function
ABCG5 and ABCG8 form an obligate heterodimer that mediates Mg(2+)- and ATP-dependent sterol transport across the cell membrane (PubMed:27144356). Plays an essential role in the selective transport of dietary plant sterols and cholesterol in and out of the enterocytes and in the selective sterol excretion by the liver into bile (PubMed:11099417, PubMed:11138003, PubMed:15054092, PubMed:27144356). Required for normal sterol homeostasis (PubMed:11099417, PubMed:11138003, PubMed:15054092). The heterodimer with ABCG8 has ATPase activity (PubMed:16893193, PubMed:20210363, PubMed:27144356).
Involvement in disease
Sitosterolemia 2
STSL2
A form of sitosterolemia, an autosomal recessive metabolic disorder characterized by unregulated intestinal absorption of cholesterol, phytosterols and shellfish sterols, and decreased biliary excretion of dietary sterols into bile. Patients have hypercholesterolemia, very high levels of plant sterols in the plasma, and frequently develop tendon and tuberous xanthomas, accelerated atherosclerosis and premature coronary artery disease.
None
The disease is caused by variants affecting the gene represented in this entry.
Post-translational modifications
N-glycosylated.
Sequence Similarities
Belongs to the ABC transporter superfamily. ABCG family. Eye pigment precursor importer (TC 3.A.1.204) subfamily.
Tissue Specificity
Strongly expressed in the liver, lower levels in the small intestine and colon.
Cellular localization
- Cell membrane
- Multi-pass membrane protein
- Apical cell membrane
- Multi-pass membrane protein
Alternative names
ATP-binding cassette sub-family G member 5, Sterolin-1, ABCG5