apolipoprotein E

(redirected from Apo E)

ap·o·lip·o·pro·tein E

an apolipoprotein found in several plasma lipoprotein particles including chylomicrons, VLDL, and HDL. Three major isoforms are encoded by three common alleles at the Apo E locus: E2, E2, and E4. The E2 allele is associated with lower total plasma cholesterol and LDL cholesterol than is E3, whereas E4 is associated with higher LDL and total cholesterol than E3.

apolipoprotein E

a protein component of lipoprotein complexes found in very-low-density lipoprotein (VLDL), high-density lipoprotein, chylomicrons, and chylomicron remnants. It facilitates hepatic uptake of chylomicron and VLDL remnants and is elevated in patients with type III hyperlipoproteinemia. One form of apolipoprotein E has been linked to Alzheimer's disease.


A gene on chromosome 19q13.2 that encodes apolipoprotein E, the main apoprotein of chylomicrons, which binds to a specific receptor on liver cells and peripheral cells. ApoE mediates binding, internalisation and catabolism of lipoprotein particles and serves as a ligand for the LDL (apo B/E) receptor.

Molecular pathology
APOE mutations cause hyperlipoproteinaemia type III (familial dysbetalipoproteinaemia), which is characterised by increased plasma cholesterol and triglycerides due to impaired chylomicron and VLDL remnant clearance.

apolipoprotein E

A 34-kD cholesterol-binding glycoprotein, which comprises 15% of VLDL; apoE maps to chromosome 19, is secreted by macrophages that mediate the uptake of lipoproteins–VLDL, HDL, LDL and cholesterol esters into cells via distinct binding domains for each receptor; apo-E has a central role in the metabolism of TG-rich lipoproteins, and mediates the uptake of chylomicrons and VLDL by the liver
References in periodicals archive ?
Mahley and his colleagues had begun studying apo E molecules long before genetic studies linked different forms of apo E to Alzheimer's disease.
When peripheral nerves are injured, white blood cells nearby make lots of apo E so they can take up lipids released by the deteriorating nerve cells, Mahley explains.
When the researchers added one type of apo E and no cholesterol-carrying particles to the nerve cells, the axons grew as if nothing had been added.