Niemann-Pick Type C1/NPC1 Proteins and Enzymes

Niemann-Pick type C1 (NPC1) is a member of a family of genes encoding membrane-bound proteins containing putative sterol sensing domains. The protein regulates cholesterol transport from late endosomes-lysosomes to other intracellular compartments. NPC1 overexpression increases both the rate of trafficking of low density lipoprotein cholesterol to the endoplasmic reticulum and the rate of delivery of endosomal cholesterol to the plasma membrane. NPC disease is an inherited neurovisceral lipid storage disorder of unesterified cholesterol accumulation in lysosomes. It is characterized by progressive neural and liver degeneration, resulting from inactivating mutations in NPC1, in most cases.