Apolipoprotein E Recombinant Rabbit Monoclonal Antibody [SC0536] (ET1610-22)

UNIPROT #

P02649

PROTEIN NAME

Apolipoprotein E

SYNONYMS

AD2 antibody;Apo-E antibody;APOE antibody;APOE_HUMAN antibody;APOEA antibody;Apolipoprotein E antibody;Apolipoprotein E3 antibody;ApolipoproteinE antibody;Apoprotein antibody;LDLCQ5 antibody;LPG antibody

SEQUENCE SIMILARITIES

Belongs to the apolipoprotein A1/A4/E family.

TISSUE SPECIFICITY

Produced by several tissues and cell types and mainly found associated with lipid particles in the plasma, the interstitial fluid and lymph. Mainly synthesized by liver hepatocytes. Significant quantities are also produced in brain, mainly by astrocytes and glial cells in the cerebral cortex, but also by neurons in frontal cortex and hippocampus. It is also expressed by cells of the peripheral nervous system. Also expressed by adrenal gland, testis, ovary, skin, kidney, spleen and adipose tissue and macrophages in various tissues.

POST-TRANSLATIONAL MODIFICATION

APOE exists as multiple glycosylated and sialylated glycoforms within cells and in plasma. The extent of glycosylation and sialylation are tissue and context specific. Plasma APOE undergoes desialylation and is less glycosylated and sialylated than the cellular form. Glycosylation is not required for proper expression and secretion. O-glycosylated with core 1 or possibly core 8 glycans. Thr-307 and Ser-314 are minor glycosylation sites compared to Ser-308.; Glycated in plasma VLDL of normal subjects, and of hyperglycemic diabetic patients at a higher level (2-3 fold).; Phosphorylated by FAM20C in the extracellular medium.; Undergoes C-terminal proteolytic processing in neurons. C-terminally truncated APOE has a tendency to form neurotoxic intracellular neurofibrillary tangle-like inclusions in neurons.

SUBCELLULAR LOCATION

Secreted, extracellular space, extracellular matrix.

FUNCTION

Apolipoprotein-E (apoE) is a protein component of plasma lipoproteins that mediates the binding, internalization and catabolism of lipoprotein particles. It can serve as a ligand for several lipoprotein receptors, including the LDL (ApoB/E) receptor and the hepatic apoE (chylomicron remnant) receptor. apoE is produced in most organs and occurs in all plasma lipoprotein fractions, constituting 10-20% of VLDL (very low density lipoprotein) and 1-2% of HDL (high density lipoprotein). Three major isoforms of apoE have been described in human (E2, E3 and E4) which differ by only one or two amino acids. Estrogen receptor has been shown to upregulate apoE gene expression via the ERa-mediated pathway, indicating a potential role for apoE in atherosclerosis. This is consistent with studies in mice in which plasma apoE levels were raised, thereby protecting the mice from diet-induced atherosclerosis. apoE has also been shown to be a potent inhibitor of proliferation and thus may play a role in angiogenesis, tumor cell growth and metastasis.