Seroatlas · Human Serome Atlas

AP2S1

AP-2 complex subunit sigma

Also known as: AP2S1_HUMAN, CLAPS2, FBH3, FBHOk, HHC3

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

Protein identityUniProt · HPA

UniProt accession
P53680
Gene
AP2S1
Ensembl
ENSG00000042753
Chromosome
19
Canonical length
142 aa
Protein class
Disease related genes, Human disease related genes, Potential drug targets, Predicted intracellular proteins, Transporters

OverviewNCBI Gene

One of two major clathrin-associated adaptor complexes, AP-2, is a heterotetramer which is associated with the plasma membrane. This complex is composed of two large chains, a medium chain, and a small chain. This gene encodes the small chain of this complex. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Jul 2014]

Canonical amino-acid sequenceUniProt

142 residues, UniProt reviewed canonical sequence.

>P53680|AP2S1
     1  MIRFILIQNR AGKTRLAKWY MQFDDDEKQK LIEEVHAVVT VRDAKHTNFV EFRNFKIIYR
    61  RYAGLYFCIC VDVNDNNLAY LEAIHNFVEV LNEYFHNVCE LDLVFNFYKV YTVVDEMFLA
   121  GEIRETSQTK VLKQLLMLQS LE

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against AP2S1 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
Cell surface
Secreted
No
Transmembrane segments
0
Mean surface accessibility (rSASA)
0.28
Highest tissue expression
209 nTPM

Expression across tissuesHPA

Tissue

  • esophagus: 209 nTPM
  • cerebral cortex: 177 nTPM
  • liver: 156 nTPM
  • amygdala: 156 nTPM
  • adrenal gland: 146 nTPM
  • hippocampal formation: 139 nTPM

Single-cell type

  • hofbauer cells: 1,390 nCPM
  • esophageal apical cells: 1,224 nCPM
  • esophageal suprabasal cells: 1,043 nCPM
  • esophageal basal cells: 602 nCPM
  • kupffer cells: 587 nCPM
  • cytotrophoblasts: 492 nCPM

Immune cell

  • myeloid DC: 718 nTPM
  • intermediate monocyte: 710 nTPM
  • total PBMC: 673 nTPM
  • classical monocyte: 642 nTPM
  • non-classical monocyte: 547 nTPM
  • plasmacytoid DC: 433 nTPM

Brain region

  • cerebral cortex: 119 nTPM
  • basal ganglia: 114 nTPM
  • hypothalamus: 113 nTPM
  • hippocampal formation: 103 nTPM
  • thalamus: 101 nTPM
  • white matter: 101 nTPM

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about AP2S1.

Disease | AllUniProt

Conditions AP2S1 is implicated in, by any mechanism.

  • Hypocalciuric hypercalcemia, familial 3 (HHC3) MIM:600740

Disease | GeneticClinVar

3 pathogenic / likely-pathogenic of 142 ClinVar records.

Conditions with pathogenic or likely-pathogenic variants.

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)
0.5
gnomAD pLI
0.79
gnomAD missense Z
2.86
DepMap mean gene effect
-0.57
DepMap dependency class
common

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 AP2S1 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 AP2S1 as an antibody target. Whether an autoantibody or antibody against AP2S1 could matter depends on whether native AP2S1 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

AP2S1 is annotated at the cell surface, where native AP2S1 is exposed to circulating antibodies and is a prime autoantibody target that could block, deplete, or overstimulate it.

Annotation status

The present source text does not explicitly label AP2S1 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/AP2S1. 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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