Apolipoprotein E (APOE)

Apolipoprotein E, 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. Apolipoprotein E has many functions in the body. When it is synthesized by the liver as part of VLDL it functions in the transport of triglycerides to the liver tissue. It is also incorporated into HDL (as HDL-E) and functions in cholesterol distribution among cells. It is also incorporated into intestinally synthesized cholymicrons and transports dietary triglycerides and cholesterol. It is involved in lipid metabolism by mediating the receptor binding of apo-E lipoproteins to the LDL receptor. Receptor binding begins the cellular uptake of lipoproteins to be used in intracellular cholesterol metabolism.