Recombinant Mouse Apolipoprotein E (Apoe)

Function

APOE is an apolipoprotein, a protein associating with lipid particles, that mainly functions in lipoprotein-mediated lipid transport between organs via the plasma and interstitial fluids. APOE is a core component of plasma lipoproteins and is involved in their production, conversion and clearance. Apolipoproteins are amphipathic molecules that interact both with lipids of the lipoprotein particle core and the aqueous environment of the plasma. As such, APOE associates with chylomicrons, chylomicron remnants, very low density lipoproteins (VLDL) and intermediate density lipoproteins (IDL) but shows a preferential binding to high-density lipoproteins (HDL). It also binds a wide range of cellular receptors including the LDL receptor/LDLR and the very low-density lipoprotein receptor/VLDLR that mediate the cellular uptake of the APOE-containing lipoprotein particles (By similarity). Finally, APOE also has a heparin-binding activity and binds heparan-sulfate proteoglycans on the surface of cells, a property that supports the capture and the receptor-mediated uptake of APOE-containing lipoproteins by cells (PubMed:23676495)

Subcellular Location

Secreted; Secreted, extracellular space; Secreted, extracellular space, extracellular matrix; Extracellular vesicle; Endosome, multivesicular body

Subunit

Homotetramer. May interact with ABCA1; functionally associated with ABCA1 in the biogenesis of HDLs. May interact with APP/A4 amyloid-beta peptide; the interaction is extremely stable in vitro but its physiological significance is unclear. May interact with MAPT. May interact with MAP2. In the cerebrospinal fluid, interacts with secreted SORL1. Interacts with PMEL; this allows the loading of PMEL luminal fragment on ILVs to induce fibril nucleation

• Horiuchi K. et al. Structure and expression of mouse apolipoprotein E gene. — J. Biochem. (1989)
• Rajavashisth T.B. et al. Evolution of apolipoprotein E: mouse sequence and evidence for an 11-nucleotide ancestral unit. — Proc. Natl. Acad. Sci. U.S.A. (1985)
• The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC). — Genome Res. (2004)
• Diedrich J.F. et al. Neuropathological changes in scrapie and Alzheimer's disease are associated with increased expression of apolipoprotein E and cathepsin D in astrocytes. — J. Virol. (1991)
• Puppione D.L. et al. Mass spectral analysis of the apolipoproteins on mouse high density lipoproteins. Detection of post-translational modifications. — Biochim. Biophys. Acta (2006)
• Lubec G. et al. PubMed: CI-92NG82E19BM4T (APR-)
• Huttlin E.L. et al. A tissue-specific atlas of mouse protein phosphorylation and expression. — Cell (2010)
• Plump A.S. et al. Severe hypercholesterolemia and atherosclerosis in apolipoprotein E-deficient mice created by homologous recombination in ES cells. — Cell (1992)