Abstract
The polytopic transmembrane protein, Niemann-Pick type C1 Like 1 (NPC1L1), is the key point of exogenous cholesterol absorption and plays an important role in cholesterol metabolism. However, the molecular mechanism of NPC1L1's role in cholesterol uptake remains unclear. NPC1L1 expression is highly regulated by a variety of molecular actors. Nuclear receptors regulate NPC1L1 expression through its promoter region. Polyunsaturated fatty acids down-regulates NPC1L1 expression by the way of sterol regulatory element binding protein 2 (SREBP2). In addition, curcumin and sphingosine-phosphate take part in the regulation of NPC1L1 expression. NPC1L1 has been recognized as an essential protein for sterol absorption and is the molecular target of ezetimibe. Moreover, inhibition of the expression of NPC1L1 has been shown to have beneficial effects on components of the metabolic syndrome. The recent progress in the structure, function and regulation of NPC1L1 is reviewed.
