Minor apolipoprotein mainly associated with HDL and to a lesser extent with VLDL. May also be associated with chylomicrons. Important determinant of plasma triglyceride (TG) levels by both being a potent stimulator of apo-CII lipoprotein lipase (LPL) TG hydrolysis and a inhibitor of the hepatic VLDL-TG production rate (without affecting the VLDL-apoB production rate). Activates poorly lecithin:cholesterol acyltransferase (LCAT) and does not enhance efflux of cholesterol from macrophages. Interacts with GPIHBP1. Up-regulated by PPARA agonists, which are used clinically to lower serum TG (such as fibrates). Liver and plasma. Belongs to the apolipoprotein A1/A4/E family. Note: This description may include information from UniProtKB.
Protein type: Lipid-binding; Secreted; Secreted, signal peptide