Seroatlas · Human Serome Atlas

APOA1

Apolipoprotein A-I

Also known as: APOA1_HUMAN

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

Protein identityUniProt · HPA

UniProt accession
P02647
Gene
APOA1
Ensembl
ENSG00000118137
Chromosome
11
Canonical length
267 aa
Protein class
Cancer-related genes, Candidate cardiovascular disease genes, Disease related genes, Human disease related genes, Metabolic proteins, Plasma proteins, Predicted intracellular proteins, Predicted secreted proteins
Subcellular location
Vesicles,Cytosol
Secretome location
Secreted to blood
Quaternary structure
Homodimer

OverviewNCBI Gene

This gene encodes apolipoprotein A-I, which is the major protein component of high density lipoprotein (HDL) in plasma. The encoded preproprotein is proteolytically processed to generate the mature protein, which promotes cholesterol efflux from tissues to the liver for excretion, and is a cofactor for lecithin cholesterolacyltransferase (LCAT), an enzyme responsible for the formation of most plasma cholesteryl esters. This gene is closely linked with two other apolipoprotein genes on chromosome 11. Defects in this gene are associated with HDL deficiencies, including Tangier disease, and with systemic non-neuropathic amyloidosis. Alternative splicing results in multiple transcript variants, at least one of which encodes a preproprotein. [provided by RefSeq, Dec 2015]

Canonical amino-acid sequenceUniProt

267 residues, UniProt reviewed canonical sequence.

>P02647|APOA1
     1  MKAAVLTLAV LFLTGSQARH FWQQDEPPQS PWDRVKDLAT VYVDVLKDSG RDYVSQFEGS
    61  ALGKQLNLKL LDNWDSVTST FSKLREQLGP VTQEFWDNLE KETEGLRQEM SKDLEEVKAK
   121  VQPYLDDFQK KWQEEMELYR QKVEPLRAEL QEGARQKLHE LQEKLSPLGE EMRDRARAHV
   181  DALRTHLAPY SDELRQRLAA RLEALKENGG ARLAEYHAKA TEHLSTLSEK AKPALEDLRQ
   241  GLLPVLESFK VSFLSALEEY TKKLNTQ

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against APOA1 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)
0.53
Highest tissue expression
20,151 nTPM

Expression across tissuesHPA

Tissue

  • liver: 20,151 nTPM
  • small intestine: 3,816 nTPM
  • duodenum: 1,608 nTPM
  • testis: 401 nTPM
  • heart muscle: 71 nTPM
  • ovary: 66 nTPM

Single-cell type

  • hepatocytes: 33,106 nCPM
  • enterocytes: 17,977 nCPM
  • sertoli cells: 553 nCPM
  • paneth cells: 329 nCPM
  • cholangiocytes: 297 nCPM
  • neuroendocrine cells: 289 nCPM

Immune cell

  • plasmacytoid DC: 1.2 nTPM
  • gdT-cell: 0.8 nTPM
  • T-reg: 0.6 nTPM
  • memory CD8 T-cell: 0.5 nTPM
  • naive CD8 T-cell: 0.5 nTPM
  • intermediate monocyte: 0.2 nTPM

Brain region

  • basal ganglia: 1 nTPM
  • cerebral cortex: 1 nTPM
  • hypothalamus: 1 nTPM
  • white matter: 1 nTPM
  • amygdala: 0.9 nTPM
  • cerebellum: 0.8 nTPM

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about APOA1.

Disease | AllUniProt

Conditions APOA1 is implicated in, by any mechanism.

  • Hypoalphalipoproteinemia, primary, 2 (FHA2) MIM:618463
  • Hypoalphalipoproteinemia, primary, 2, intermediate (FHA2I) MIM:619836
  • Familial apolipoprotein gene cluster deletion syndrome (FAPLDS) MIM:620058
  • Amyloidosis, hereditary systemic 3 (AMYLD3) MIM:620657

Disease | GeneticClinVar

33 pathogenic / likely-pathogenic of 390 ClinVar records.

Conditions with pathogenic or likely-pathogenic variants.

Disease | ImmuneIEDB

Conditions an epitope on APOA1 was assayed in.

Disease | AutoantibodyPubMed

Conditions in which antibodies against APOA1 are reported. Each links to that disease's full target list.

Showing 5 of 7 — disease pages carrying at least 10 antigens.

ReferencesPubMed · IEDB

Publications for APOA1 from three distinct lines of evidence, kept separate because they answer different questions: whether antibodies are directed at the protein, whether a B-cell epitope has been mapped on it, and whether a T-cell epitope has. Each is labelled with its source.

Reference: AutoantibodyPubMed

52 publications

Show 20 more of 52 total

Reference: B cellIEDB

2 publications

Sources: PubMed — antigen-level antibody evidence from a custom retrieval. Records matching a controlled set of autoantibody terms (the MeSH descriptors Autoantibodies and Autoantigens, with title and abstract term variants) were obtained through NCBI E-utilities, and their titles and abstracts parsed for constructions that direct an antibody at a named protein rather than for co-occurrence. Captured names were resolved against UniProt nomenclature and each antigen adjudicated individually against the source text. IEDB — curated epitope assays from the Immune Epitope Database (Vita et al., Nucleic Acids Research 2019). Bibliographic records from PubMed and MeSH, U.S. National Library of Medicine; citation metrics from NIH iCite (Hutchins et al., PLoS Biology 2016). Titles link to PubMed; abstracts are not reproduced here. The NLM does not endorse this analysis.

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)
1.34
gnomAD pLI
0
gnomAD missense Z
0.51
DepMap mean gene effect
0.08
DepMap dependency class
selective

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 2% 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 APOA1 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 APOA1 as an antibody target. Whether an autoantibody or antibody against APOA1 could matter depends on whether native APOA1 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

APOA1 is annotated as secreted, so native APOA1 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 APOA1 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/APOA1. 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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