Apolipoprotein E (APOE), a main apoprotein of the chylomicron, binds to a specific receptor on liver cells and peripheral cells. APOE is essential for the normal catabolism of triglyceride-rich lipoprotein constituents. APOE was initially recognized for its importance in lipoprotein metabolism and cardiovascular disease.
More recently, it has been studied for its role in several biological processes not directly related to lipoprotein transport, including Alzheimer's disease, immunoregulation, and cognition. Defects in APOE result in familial dysbetalipoproteinemia, or type III hyperlipoproteinemia (HLP III), in which increased plasma cholesterol and triglycerides are the consequence of impaired clearance of chylomicron and VLDL remnants.
Single nucleotide polymorphisms (SNPs)