General Info

HMG-CoA synthase is an enzyme that catalyzes an important step in the synthesis of cholesterol. It catalyzes the reaction of acetoacetyl CoA with acetyl CoA and water to give HMG-CoA and CoA. This intermediate is then reduced to mevalate for the synthesis of cholesterol.

HMG-CoA synthase exists in both the cytosol and the mitochondria of the cell. The difference between the two is what the HMG-CoA is reduced to. In the cytosol, it forms mevalonate. In the mitochondria, it forms acetyl CoA and acetoacetate. The majority of HMG-CoA synthase is located in the mitochondria.

The full-length DNA transcript for mitochondrial HMG-CoA synthase spans 1994 nucleotides.

Regulation of HMG-CoA synthase is stimulated in a number of physiological situations (fasting, prolonged exercise, high-fat diet), and also in diabetes. All these conditions also modify the expression of the gene for mitochondrial HMG-CoA synthase.