ATP-citrate lyase (ACL) is a homotetramer that catalyzes the formation of acetyl-CoA and oxaloacetate (OAA) in the cytosol, which is the keystep for the biosynthesis of fatty acids, cholesterol and acetylcholine, as well as for glucogenesis. Nutrients and hormones regulate theexpression level and phosphorylation of ATP-citrate lyase. It is phosphorylated by GSK-3 on Thr446 and Ser450. Ser455 of ATP-citrate lyasehas been reported to be phosphorylated by PKA and Akt. Phosphorylation on Ser455 abolishes the homotropic allosteric regulation by citrateand enhances the catalytic activity of the enzyme.
