Seroatlas · Human Serome Atlas

AP1AR

AP-1 complex-associated regulatory protein

Also known as: 2C18, AP1AR_HUMAN, C4orf16, gamma-BAR, PRO0971

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

Protein identityUniProt · HPA

UniProt accession
Q63HQ0
Gene
AP1AR
Ensembl
ENSG00000138660
Chromosome
4
Canonical length
302 aa
Protein class
Predicted intracellular proteins
Subcellular location
Golgi apparatus

OverviewNCBI Gene

Enables AP-1 adaptor complex binding activity and kinesin binding activity. Involved in negative regulation of receptor recycling and vesicle targeting, trans-Golgi to endosome. Acts upstream of or within negative regulation of substrate adhesion-dependent cell spreading. Located in Golgi apparatus and transport vesicle. [provided by Alliance of Genome Resources, Jul 2025]

Canonical amino-acid sequenceUniProt

302 residues, UniProt reviewed canonical sequence.

>Q63HQ0|AP1AR
     1  MGNCCWTQCF GLLRKEAGRL QRVGGGGGSK YFRTCSRGEH LTIEFENLVE SDEGESPGSS
    61  HRPLTEEEIV DLRERHYDSI AEKQKDLDKK IQKELALQEE KLRLEEEALY AAQREAARAA
   121  KQRKLLEQER QRIVQQYHPS NNGEYQSSGP EDDFESCLRN MKSQYEVFRS SRLSSDATVL
   181  TPNTESSCDL MTKTKSTSGN DDSTSLDLEW EDEEGMNRML PMRERSKTEE DILRAALKYS
   241  NKKTGSNPTS ASDDSNGLEW ENDFVSAEMD DNGNSEYSGF VNPVLELSDS GIRHSDTDQQ
   301  TR

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against AP1AR 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
Intracellular
Secreted
No
Transmembrane segments
0
Mean surface accessibility (rSASA)
0.62
Highest tissue expression
39 nTPM

Expression across tissuesHPA

Tissue

  • parathyroid gland: 39 nTPM
  • small intestine: 22 nTPM
  • duodenum: 21 nTPM
  • kidney: 21 nTPM
  • liver: 19 nTPM
  • colon: 17 nTPM

Single-cell type

  • early spermatids: 121 nCPM
  • late spermatids: 94 nCPM
  • salivary acinar cells: 86 nCPM
  • smooth muscle cells: 83 nCPM
  • urothelial cells: 79 nCPM
  • enterocytes: 74 nCPM

Immune cell

  • intermediate monocyte: 10 nTPM
  • myeloid DC: 9.5 nTPM
  • NK-cell: 9 nTPM
  • naive CD8 T-cell: 8.9 nTPM
  • naive CD4 T-cell: 8.5 nTPM
  • non-classical monocyte: 8.5 nTPM

Brain region

  • cerebellum: 18 nTPM
  • cerebral cortex: 16 nTPM
  • hippocampal formation: 16 nTPM
  • hypothalamus: 16 nTPM
  • white matter: 14 nTPM
  • basal ganglia: 14 nTPM

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)
0.56
gnomAD pLI
0.14
gnomAD missense Z
1.19
DepMap mean gene effect
0.07
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

  • AP-1 complex-associated regulatory protein
  • AP-1 complex-associated regulatory protein

KeywordsUniProt

InteractionsUniProt · HPA

Protein binding partners of AP1AR 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 AP1AR as an antibody target. Whether an autoantibody or antibody against AP1AR could matter depends on whether native AP1AR is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

AP1AR is annotated as predominantly intracellular. Intracellular proteins are common autoantibody markers, becoming visible to the immune system after cell injury or altered processing, but are usually markers of disease rather than direct drivers.

Annotation status

The present source text does not explicitly label AP1AR as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/AP1AR. 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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