ATP-binding cassette subfamily G member 8 (ABCG8)

ATP-binding cassette subfamily G member 8 (ABCG8) is a membrane-bound **half-transporter** that, when heterodimerized with ABCG5, plays a critical role in controlling the transport of cholesterol and plant sterols across cell membranes in the liver and intestine[1][2][3][4][5]. It is essential for excluding non-cholesterol sterols from absorption in the intestine and promoting their excretion into bile in the liver, thereby maintaining whole-body sterol homeostasis. Mutations in ABCG8 cause sitosterolemia, leading to excessive absorption and reduced excretion of dietary plant sterols, increasing the risk of premature atherosclerosis and gallstone disease. ABCG8 function is tightly regulated by liver X receptor (LXR) signaling and by its obligate heterodimerization with ABCG5. Its relevance spans lipid metabolism disorders, cardiovascular disease, and gallstone pathogenesis, and its expression or mutation status may serve as a biomarker for lipid transport-related diseases and guide personalized therapeutic strategies[1][2][3][4][5].

Other names

Sterolin-2Gallbladder disease 4 (GBD4)STSLSTSL1ATP-binding cassette, sub-family G (WHITE), member 8Sterolin 2ABCG8

Drugs influencing ABCG8 pathways primarily act by inducing ABCG8 expression (e.g., via Liver X Receptor (LXR) agonism) to increase sterol efflux. Indirect reduction of plant sterol and cholesterol absorption is achieved by limiting their transport into circulation through ABCG8's natural function. Additionally, cholesterol absorption inhibition at the intestinal level via non-ABCG8 targets (like Ezetimibe acting on NPC1L1) can complement ABCG8 function in sterol homeostasis.