P0DUI8 · APOE_DICSH

Function

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. Finally, APOE has also 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.

Features

Showing features for binding site.

131020406080100120140160180200220240260280300
TypeIDPosition(s)Description
Binding site159-162heparin (UniProtKB | ChEBI)
Binding site222-229heparin (UniProtKB | ChEBI)

GO annotations

AspectTerm
Cellular Componentchylomicron
Cellular Componentextracellular exosome
Cellular Componenthigh-density lipoprotein particle
Cellular Componentmultivesicular body, internal vesicle
Cellular Componentvery-low-density lipoprotein particle
Molecular Functionheparin binding
Molecular Functionlipid binding
Biological Processlipid transport
Biological Processlipoprotein metabolic process
Biological Processmelanosome organization

Keywords

Names & Taxonomy

Protein names

  • Recommended name
    Apolipoprotein E
  • Short names
    Apo-E

Gene names

    • Name
      APOE

Organism names

Accessions

  • Primary accession
    P0DUI8

Subcellular Location

Secreted
Extracellular vesicle
Note: In the plasma, APOE is associated with chylomicrons, chylomicrons remnants, VLDL, LDL and HDL lipoproteins. Lipid poor oligomeric APOE is associated with the extracellular matrix in a calcium- and heparan-sulfate proteoglycans-dependent manner. Lipidation induces the release from the extracellular matrix. Colocalizes with CD63 and PMEL at exosomes and in intraluminal vesicles within multivesicular endosomes.

Keywords

PTM/Processing

Features

Showing features for signal, chain.

TypeIDPosition(s)Description
Signal1-18
ChainPRO_000045245319-310Apolipoprotein E

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.
Glycated in plasma VLDL.
Phosphorylated by FAM20C in the extracellular medium.

Keywords

Interaction

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.

Structure

Family & Domains

Features

Showing features for repeat, region.

TypeIDPosition(s)Description
Repeat77-981
Region77-2488 X 22 AA approximate tandem repeats
Repeat99-1202
Repeat121-1423
Repeat143-1644
Region155-165LDL and other lipoprotein receptors binding
Repeat165-1865
Repeat187-2086
Region207-283Lipid-binding and lipoprotein association
Repeat209-2267
Repeat227-2488
Region259-310Homooligomerization
Region271-283Specificity for association with VLDL

Sequence similarities

Belongs to the apolipoprotein A1/A4/E family.

Keywords

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Sequence processing
    The displayed sequence is further processed into a mature form.
  • Length
    310
  • Mass (Da)
    35,389
  • Last updated
    2021-04-07 v1
  • Checksum
    AE108949BA87BF07
MKVLWPALVVTLLAGCRADVEPGPEVQLGKEWATWQASQPWEQALGRFWNYLRWVQTLSEQVQEELLSSQVTEELTALMDDTMKEVKACKSELEEQLGPVAEETKARVSKELQAAQARLGADMEEVRNRLAQYRGELQAMVGQSTEELRGRLNAHLRKLRKRLLRDAEDLQQRLAVYQAGIREGAERSVNTLREHLGPLAEQAATMHTLVSKPLQERAEAWAQRLRGRLEKAGFPVGDRLDEVREQVQEVRAKVEEQANQVRLQAEAFQGRLKSWFEPLVQDMQQKWAELVEKVQLALRAVPTSVPSEKQ

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
JABWHU010001658
EMBL· GenBank· DDBJ
-Genomic DNA No translation available.

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Disclaimer

Any medical or genetic information present in this entry is provided for research, educational and informational purposes only. It is not in any way intended to be used as a substitute for professional medical advice, diagnosis, treatment or care. Our staff consists of biologists and biochemists that are not trained to give medical advice.
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