Niemann-Pick C1-like intracellular cholesterol transporter 1 (NPC1L1)

Niemann-Pick C1-like intracellular cholesterol transporter 1 is a multi-pass membrane protein primarily expressed on epithelial cells of the gastrointestinal tract and hepatocytes. It plays a critical role in mediating the uptake and transport of dietary and biliary free cholesterol into enterocytes through vesicular endocytosis, thus regulating whole-body lipid homeostasis. The protein also facilitates plant sterol absorption at lower rates than for cholesterol, as well as alpha-tocopherol transport. It is directly inhibited by ezetimibe, a clinically approved drug for lowering plasma LDL-cholesterol by reducing intestinal absorption. Polymorphic variations in its gene are associated with differences in plasma lipid levels and coronary heart disease risk. Beyond cardiovascular implications, it has been implicated as an accessory receptor for hepatitis C virus entry into cells. The transporter belongs to the patched family of proteins.

Other names

NPC1L1Niemann-Pick C1-like protein 1NPC1-like intracellular cholesterol transporter 1NPC1-like 1

Inhibition of intestinal and hepatic cholesterol absorption by blocking the function of NPC1L1, leading to reduced blood LDL-cholesterol levels; ezetimibe binds directly to this protein to exert its effect