apolipoprotein E

(redirected from APOE gene)

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.

APOE

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 ?
Alleles of the ApoE gene have been implicated in susceptibility to cardiovascular disease (17, 18) and sporadic late-onset Alzheimer disease (19-21); some reports have indicated that expression of the ApoE alleles may be differentially regulated (22, 23).
APOE genotyping was performed with the primer set F6/F4 (Amersham/Pharmacia Biotech Inc.), which amplifies part of exon 4 of the APOE gene, including the coding sequence for amino acid residues 112 and 158 (11).
ApoE is encoded by a polymorphic gene on chromosome 19 (the APOE gene), and three alleles ([member of]2, [member of]3, and [member of]4) have been described.
ApoE gene amplification and typing were performed as described by Saunders et al.
The sequences of oligonucleotides oligo 3 and oligo 4 were identical to the one around codon 112 of the APOE gene; oligonucleotides oligo 3b and oligo 2 are the same as the sequence around codon 158 of the APOE gene.
Hegele's finding of unique disease-causing mutations in the APOE gene during routine genotyping for Alzheimer disease highlights the continuing need for broad patient-oriented clinical observation and intervention as genetic discoveries and tests move from the research laboratory into clinical use.
Our data suggest that women who inherit distinct alleles of the APOE gene may require individualized ERT or combination therapy.
In familial defective apolipoprotein B-100, the clearance of LDL particles from the circulation is impaired because of reduced affinity of the apolipoprotein (apo) B component of LDL for the LDL receptor as a result of a G-to-A mutation at nucleotide 10708 in exon 26 of the apoE gene, which causes substitution of [Arg.sup.3500] for Gln (1, 2).
In one, they focused on the APOE gene; certain variants of that gene are linked to a relatively higher risk of Alzheimer's disease.
Genotyping, particularly of ApoE gene alleles is also useful in the evaluation of cases and planning management.
To establish ApoE knock-out mice lines, Piedrahita with co-authors disrupted ApoE gene in mouse ES cells using electroporation with plasmids of the replacement type to induce HR, after which, modified ES cells were injected into mouse blastocysts.
The APOE gene encodes apolipoprotein E, a lipid-transporting protein in the brain.