3-Hydroxy-3-methylglutaryl-CoA reductase (HMGCR) is a transmembrane glycoprotein of the endoplasmic reticulum. It is the rate-limiting enzyme for cholesterol biosynthesis and non-sterol isoprenoid biosynthesis. Play a key role in cellular cholesterol homeostasis. The activity of HMGCR is regulated by negative feedback, in which cholesterol and other end products of the metabolic pathway inhibit the activity of HMGCR in a multivalent manner. Cholesterol inhibits reductase activity mainly by inhibiting the transcription rate of HMGCR gene. HMGCR is the main target of statins, which are a class of cholesterol-lowering drugs.
