Seroatlas · Human Serome Atlas

APOE

Apolipoprotein E

Also known as: AD2, APOE_HUMAN

Cross-references: UniProt · Ensembl · Human Protein Atlas · GeneCards · NCBI Gene

Protein identityUniProt · HPA

UniProt accession
P02649
Gene
APOE
Ensembl
ENSG00000130203
Chromosome
19
Canonical length
317 aa
Protein class
Cancer-related genes, Candidate cardiovascular disease genes, Disease related genes, Human disease related genes, Metabolic proteins, Plasma proteins, Predicted secreted proteins
Subcellular location
Vesicles
Secretome location
Secreted to blood
Quaternary structure
Homotetramer

OverviewNCBI Gene

The protein encoded by this gene is a major apoprotein of the chylomicron. It binds to a specific liver and peripheral cell receptor, and is essential for the normal catabolism of triglyceride-rich lipoprotein constituents. This gene maps to chromosome 19 in a cluster with the related apolipoprotein C1 and C2 genes. Mutations in this gene result in familial dysbetalipoproteinemia, or type III hyperlipoproteinemia (HLP III), in which increased plasma cholesterol and triglycerides are the consequence of impaired clearance of chylomicron and VLDL remnants. [provided by RefSeq, Jun 2016]

Canonical amino-acid sequenceUniProt

317 residues, UniProt reviewed canonical sequence.

>P02649|APOE
     1  MKVLWAALLV TFLAGCQAKV EQAVETEPEP ELRQQTEWQS GQRWELALGR FWDYLRWVQT
    61  LSEQVQEELL SSQVTQELRA LMDETMKELK AYKSELEEQL TPVAEETRAR LSKELQAAQA
   121  RLGADMEDVC GRLVQYRGEV QAMLGQSTEE LRVRLASHLR KLRKRLLRDA DDLQKRLAVY
   181  QAGAREGAER GLSAIRERLG PLVEQGRVRA ATVGSLAGQP LQERAQAWGE RLRARMEEMG
   241  SRTRDRLDEV KEQVAEVRAK LEEQAQQIRL QAEAFQARLK SWFEPLVEDM QRQWAGLVEK
   301  VQAAVGTSAA PVPSDNH

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against APOE can act on the native protein depends on physical access: surface and secreted proteins are reachable by circulating antibodies, intracellular proteins usually are not.

Antibody reachability
Secreted
Secreted
Yes
Transmembrane segments
0
Mean surface accessibility (rSASA)
0.42
Highest tissue expression
6,534 nTPM

Expression across tissuesHPA

Tissue

  • liver: 6,534 nTPM
  • adrenal gland: 3,391 nTPM
  • midbrain: 2,715 nTPM
  • basal ganglia: 2,691 nTPM
  • amygdala: 1,947 nTPM
  • hypothalamus: 1,368 nTPM

Single-cell type

  • hepatocytes: 9,962 nCPM
  • müller glia: 6,740 nCPM
  • peritubular myoid cells: 4,352 nCPM
  • melanocytes: 3,427 nCPM
  • leydig cells: 2,556 nCPM
  • macrophages: 1,733 nCPM

Immune cell

  • basophil: 0 nTPM
  • classical monocyte: 0 nTPM
  • eosinophil: 0 nTPM
  • gdT-cell: 0 nTPM
  • intermediate monocyte: 0 nTPM
  • MAIT T-cell: 0 nTPM

Brain region

  • basal ganglia: 2,062 nTPM
  • pons: 2,008 nTPM
  • midbrain: 1,855 nTPM
  • medulla oblongata: 1,797 nTPM
  • thalamus: 1,734 nTPM
  • white matter: 1,677 nTPM

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about APOE.

Disease | AllUniProt

Conditions APOE is implicated in, by any mechanism.

Disease | GeneticClinVar

19 pathogenic / likely-pathogenic of 280 ClinVar records.

Conditions with pathogenic or likely-pathogenic variants.

Disease | ImmuneIEDB

Conditions an epitope on APOE was assayed in.

Genetic constraint and essentialitygnomAD · DepMap

Does the body need this protein intact? Low LOEUF or a strong DepMap dependency means loss or blockade of the protein is likely to be felt.

gnomAD LOEUF (loss-of-function intolerance)
1.03
gnomAD pLI
0
gnomAD missense Z
0.74
DepMap mean gene effect
-0.02
DepMap dependency class
none

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 4% of surveyed tumor types (aggregate summary; per-cohort expression, alteration, and survival load in the interactive view).

OntologyGO

Biological processes

Molecular functions

Cellular components

Protein domainsUniProt · Pfam · InterPro

KeywordsUniProt

InteractionsUniProt · HPA

Protein binding partners of APOE in the human serome: UniProt-annotated complex subunits plus reported interactors. Each links to its own Seroatlas record.

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads APOE as an antibody target. Whether an autoantibody or antibody against APOE could matter depends on whether native APOE is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

APOE is annotated as secreted, so native APOE circulates and is directly accessible to antibodies. Secreted and cell-surface proteins are the autoantibody targets most likely to act like drugs, blocking or depleting the native protein.

Annotation status

The present source text does not explicitly label APOE as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/APOE. Study-independent annotations aggregated from UniProt, Human Protein Atlas, PubMed, IEDB, Pfam, InterPro, Gene Ontology, AlphaFold, gnomAD, DepMap, ClinVar, TCGA. Catalog release seroatlas-reviewed-human-uniprot-20260313.

Seroatlas is the reference for exploring autoantibody and antibody serology at the human-protein level: the autoreactome and human serome, multiplex serology (HuProt, HuScan, VirScan, PhIP-Seq).

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