Seroatlas · Human Serome Atlas

XAGE3

X antigen family member 3

Also known as: CT12.3a, CT12.3b, GAGED4, PLAC6, pp9012, XAGE-3, XAGE3_HUMAN

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

Protein identityUniProt · HPA

UniProt accession
Q8WTP9
Gene
XAGE3
Ensembl
ENSG00000171402
Chromosome
X
Canonical length
111 aa
Protein class
Predicted intracellular proteins
Subcellular location
Vesicles,Plasma membrane

OverviewNCBI Gene

This gene is a member of the XAGE subfamily, which belongs to the GAGE family. The GAGE genes are expressed in a variety of tumors and in some fetal and reproductive tissues. This gene is expressed in placenta and fetal liver/spleen, and may function in inhibiting cancer cell growth. The protein encoded by this gene shares a sequence similarity with other GAGE/PAGE proteins. Because of the expression pattern and the sequence similarity, this protein also belongs to a family of CT (cancer-testis) antigens. Alternative splicing of this gene generates 2 transcript variants differing in the 5' UTR. [provided by RefSeq, Jul 2008]

Canonical amino-acid sequenceUniProt

111 residues, UniProt reviewed canonical sequence.

>Q8WTP9|XAGE3
     1  MIWRGRSTYR PRPRRSVPPP ELIGPMLEPG DEEPQQEEPP TESRDPAPGQ EREEDQGAAE
    61  TQVPDLEADL QELSQSKTGG ECGNGPDDQG KILPKSEQFK MPEGGDRQPQ V

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against XAGE3 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
Unknown
Secreted
No
Transmembrane segments
0
Mean surface accessibility (rSASA)
0.69
Highest tissue expression
358 nTPM

Expression across tissuesHPA

Tissue

  • placenta: 358 nTPM
  • adipose tissue: 2.9 nTPM
  • liver: 1.9 nTPM
  • testis: 1.4 nTPM
  • epididymis: 0.5 nTPM
  • breast: 0.4 nTPM

Single-cell type

  • migrating cytotrophoblasts: 3,157 nCPM
  • syncytiotrophoblasts: 3,075 nCPM
  • cytotrophoblasts: 2,353 nCPM
  • extravillous trophoblasts: 1,500 nCPM
  • hofbauer cells: 33 nCPM
  • early primary spermatocytes: 16 nCPM

Immune cell

  • memory B-cell: 0.2 nTPM
  • basophil: 0 nTPM
  • classical monocyte: 0 nTPM
  • eosinophil: 0 nTPM
  • gdT-cell: 0 nTPM
  • intermediate monocyte: 0 nTPM

Brain region

  • white matter: 0.3 nTPM
  • cerebral cortex: 0.1 nTPM
  • amygdala: 0 nTPM
  • basal ganglia: 0 nTPM
  • cerebellum: 0 nTPM
  • choroid plexus: 0 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)
1.31
gnomAD pLI
0.09
gnomAD missense Z
-0.58
DepMap mean gene effect
-0.25
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).

Protein domainsUniProt · Pfam · InterPro

InteractionsUniProt · HPA

Protein binding partners of XAGE3 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 XAGE3 as an antibody target. Whether an autoantibody or antibody against XAGE3 could matter depends on whether native XAGE3 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

XAGE3 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 XAGE3 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/XAGE3. 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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