Plays a major role in cholesterol homeostasis . Critical for the uptake of cholesterol across the plasma membrane of the intestinal enterocyte . Involved in plant sterol absorption, it transports sitosterol, although at lower rates than cholesterol (By similarity). Is the direct molecular target of ezetimibe, a drug that inhibits cholesterol absorption and is approved for the treatment of hypercholesterolemia . May have a function in the transport of multiple lipids and their homeostasis, thereby influencing lipid metabolism regulation . May be involved in caveolin trafficking from the plasma membrane (By similarity). In addition, acts as a negative regulator of NPC2 and down-regulates its expression and secretion by inhibiting its maturation and accelerating its degradation .
Subcellular locations: Apical cell membrane, Cell membrane, Cytoplasmic vesicle membrane
Subfractionation of brush border membranes from proximal enterocytes suggests considerable association with the apical membrane fraction. Exists as a predominantly cell surface membrane expressed protein (By similarity). According to , localizes in a subcellular vesicular compartment rich in RAB5.
Widely expressed. Expressed in liver. Also expressed in small intestine, pancreas, kidney, lung, pancreas, spleen, heart, gall bladder, brain, testis, stomach and muscle.