Search by BoMiProt ID - Bomi223

Primary Information

BoMiProt ID Bomi223
Protein Name Apolipoprotein E
Organism Bos taurus
Uniprot IDQ03247
Milk FractionWhey, MFGM, Exosome
Ref Sequence ID NP_776416.1
Aminoacid Length 316
Molecular Weight 35980
FASTA Sequence Download
Gene Name APOE
Gene ID 281004
Protein Existence Status Reviewed: Experimental evidence at protein level

Secondary Information

Presence in other biological fluids/tissue/cells the liver, brain, spleen, lungs, adrenal gland, ovaries, kidneys, and muscles as found in humans
Protein Function Component of plasma lipoproteins in the transport of lipids among cells of different organs and within specific tissues; Mediate the binding of lipoproteins or lipid complexes in the plasma or interstitial fluids to specific cell-surface receptors; participates in the distribution/redistribution of lipids among various tissues and cells of the body; plays a key role in regulating the clearance of these lipoproteins from the plasma
Biochemical Properties associated with very low density lipoproteins; intermediate density lipoproteins, chylomicron remnants, and certain subclasses of high-density lipoproteins; ApoE mediates the interaction of apoE-containing lipoproteins and lipid complexes to the LDL receptor, the LDL receptor related protein (LRP), the VLDL receptor, the apoE receptor-2, and gp330; Arginine 158 appears to be involved in modulating the conformation of the 136–150 region and is involved only indirectly in receptor binding activity. ApoE3 and apoE4, which display normal receptor binding activity, have arginine at residue 158, whereas apoE2, which is defective in receptor binding activity, has cysteine.
Significance in milk Related to lipid transport; expression decreases over lactation period
PTMs Glycosylated: human mature apolipoprotein E (ApoE) is a 299-amino acid glycoprotein (34–37 kDa); various other PTMs include methylation, Dihydroxylation, dimethylation; four glycosylation sites (T194, T289, S290, and S296 residues) on secreted and cellular human ApoE
Site(s) of PTM(s)

N-glycosylation, O-glycosylation,
>sp|Q03247|APOE_BOVIN Apolipoprotein E OS=Bos taurus OX=9913 GN=APOE PE=1 SV=1
Predicted Disorder Regions NA
DisProt Annotation
TM Helix Prediction No TM helices
Significance of PTMs serves as a ligand for the low-density lipoprotein (LDL) receptor (LDLR), that is involved in lipid metabolism; alter the domain interactions, functions, binding affinities, hydrophobicity, and structural stability of ApoE; glycation at the K75 position may impair lipoprotein-cell interactions through heparan sulfate proteoglycans, andmay lead to enhancement of lipid abnormalities in diabetic patients
Bibliography 1. Chartier-Hariln, M.-C. et al. (1994) ‘Apolipoprotein E, ɛ4 allele as a major risk factor for sporadic early and late-onset forms of Alzheimer’s disease: analysis of the 19q13.2 chromosomal region’, Human Molecular Genetics, 3(4), pp. 569–574. doi: 10.1093/hmg/3.4.569.
2. Uen, Y.-H. et al. (2015) ‘Analysis of differentially expressed novel post-translational modifications of plasma apolipoprotein E in Taiwanese females with breast cancer’, Journal of Proteomics, 126, pp. 252–262. doi: 10.1016/j.jprot.2015.05.038.
3. Mahley, R. W. (2016) ‘Apolipoprotein E: from cardiovascular disease to neurodegenerative disorders’, Journal of Molecular Medicine, 94(7), pp. 739–746. doi: 10.1007/s00109-016-1427-y.