Seroatlas · Human Serome Atlas

GPA33

Cell surface A33 antigen

Also known as: A33, GPA33_HUMAN

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

Protein identityUniProt · HPA

UniProt accession
Q99795
Gene
GPA33
Ensembl
ENSG00000143167
Chromosome
1
Canonical length
319 aa
Protein class
Cancer-related genes, Plasma proteins, Predicted intracellular proteins, Predicted membrane proteins

OverviewNCBI Gene

The glycoprotein encoded by this gene is a cell surface antigen that is expressed in greater than 95% of human colon cancers. The open reading frame encodes a 319-amino acid polypeptide having a putative secretory signal sequence and 3 potential glycosylation sites. The predicted mature protein has a 213-amino acid extracellular region, a single transmembrane domain, and a 62-amino acid intracellular tail. The sequence of the extracellular region contains 2 domains characteristic of the CD2 subgroup of the immunoglobulin (Ig) superfamily. [provided by RefSeq, Jul 2008]

Canonical amino-acid sequenceUniProt

319 residues, UniProt reviewed canonical sequence.

>Q99795|GPA33
     1  MVGKMWPVLW TLCAVRVTVD AISVETPQDV LRASQGKSVT LPCTYHTSTS SREGLIQWDK
    61  LLLTHTERVV IWPFSNKNYI HGELYKNRVS ISNNAEQSDA SITIDQLTMA DNGTYECSVS
   121  LMSDLEGNTK SRVRLLVLVP PSKPECGIEG ETIIGNNIQL TCQSKEGSPT PQYSWKRYNI
   181  LNQEQPLAQP ASGQPVSLKN ISTDTSGYYI CTSSNEEGTQ FCNITVAVRS PSMNVALYVG
   241  IAVGVVAALI IIGIIIYCCC CRGKDDNTED KEDARPNREA YEEPPEQLRE LSREREEEDD
   301  YRQEEQRSTG RESPDHLDQ

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against GPA33 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
1
Mean surface accessibility (rSASA)
0.4
Highest tissue expression
202 nTPM

Expression across tissuesHPA

Tissue

  • colon: 202 nTPM
  • rectum: 184 nTPM
  • duodenum: 141 nTPM
  • small intestine: 129 nTPM
  • appendix: 18 nTPM
  • lung: 6.7 nTPM

Single-cell type

  • cardiomyocytes: 797 nCPM
  • colonocytes: 636 nCPM
  • enterocytes: 297 nCPM
  • goblet cells: 293 nCPM
  • enteric transient amplifying cells: 131 nCPM
  • myonuclei: 87 nCPM

Immune cell

  • naive CD4 T-cell: 24 nTPM
  • T-reg: 20 nTPM
  • memory CD4 T-cell: 11 nTPM
  • total PBMC: 6.8 nTPM
  • memory CD8 T-cell: 5.7 nTPM
  • intermediate monocyte: 3.8 nTPM

Brain region

  • choroid plexus: 0.9 nTPM
  • hypothalamus: 0.5 nTPM
  • thalamus: 0.5 nTPM
  • cerebral cortex: 0.4 nTPM
  • pons: 0.3 nTPM
  • midbrain: 0.2 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)
1.07
gnomAD pLI
0
gnomAD missense Z
0.01
DepMap mean gene effect
-0.1
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

Molecular functions

Cellular components

Protein domainsUniProt · Pfam · InterPro

KeywordsUniProt

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads GPA33 as an antibody target. Whether an autoantibody or antibody against GPA33 could matter depends on whether native GPA33 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

GPA33 is annotated at the cell surface, where native GPA33 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 GPA33 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/GPA33. 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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