Seroatlas · Human Serome Atlas

SSX3

Protein SSX3

Also known as: CT5.3, SSX3_HUMAN

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

Protein identityUniProt · HPA

UniProt accession
Q99909
Gene
SSX3
Ensembl
ENSG00000165584
Chromosome
X
Canonical length
188 aa
Protein class
Predicted intracellular proteins
Subcellular location
Nucleoplasm,Nucleoli

OverviewNCBI Gene

The product of this gene belongs to the family of highly homologous synovial sarcoma X (SSX) breakpoint proteins. These proteins may function as transcriptional repressors. They are also capable of eliciting spontaneous humoral and cellular immune responses in cancer patients, and are potentially useful targets in cancer vaccine-based immunotherapy. While some of the related SSX genes are involved in t(X;18)(p11.2;q11.2) translocations that are characteristically found in all synovial sarcomas, this gene does not appear to be involved in such translocations. [provided by RefSeq, Jul 2013]

Canonical amino-acid sequenceUniProt

188 residues, UniProt reviewed canonical sequence.

>Q99909|SSX3
     1  MNGDDTFARR PTVGAQIPEK IQKAFDDIAK YFSKEEWEKM KVSEKIVYVY MKRKYEAMTK
    61  LGFKAILPSF MRNKRVTDFQ GNDFDNDPNR GNQVQRPQMT FGRLQGIFPK IMPKKPAEEG
   121  NVSKEVPEAS GPQNDGKQLC PPGKPTTSEK INMISGPKRG EHAWTHRLRE RKQLVIYEEI
   181  SDPEEDDE

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against SSX3 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
12 nTPM

Expression across tissuesHPA

Tissue

  • testis: 12 nTPM
  • bone marrow: 0.1 nTPM
  • thyroid gland: 0.1 nTPM
  • adipose tissue: 0 nTPM
  • adrenal gland: 0 nTPM
  • amygdala: 0 nTPM

Single-cell type

  • differentiating spermatogonia: 178 nCPM
  • early primary spermatocytes: 136 nCPM
  • undifferentiated spermatogonia: 18 nCPM
  • late spermatids: 2.8 nCPM
  • peritubular myoid cells: 0.7 nCPM
  • early spermatids: 0.4 nCPM

Immune cell

  • basophil: 0.2 nTPM
  • eosinophil: 0.1 nTPM
  • memory B-cell: 0.1 nTPM
  • naive B-cell: 0.1 nTPM
  • classical monocyte: 0 nTPM
  • gdT-cell: 0 nTPM

Brain region

  • cerebral cortex: 2.2 nTPM
  • white matter: 2 nTPM
  • medulla oblongata: 1.4 nTPM
  • amygdala: 1.3 nTPM
  • hypothalamus: 1.3 nTPM
  • basal ganglia: 1.2 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)
1.28
gnomAD pLI
0.01
gnomAD missense Z
-0.48
DepMap mean gene effect
-0.09
DepMap dependency class
selective

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 3% of surveyed tumor types (aggregate summary; per-cohort expression, alteration, and survival load in the interactive view).

OntologyGO

Biological processes

Cellular components

Protein domainsUniProt · Pfam · InterPro

KeywordsUniProt

InteractionsUniProt · HPA

Protein binding partners of SSX3 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 SSX3 as an antibody target. Whether an autoantibody or antibody against SSX3 could matter depends on whether native SSX3 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

SSX3 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.

Source-annotated serology context

The source annotations explicitly mention antibody, autoantibody, autoantigen, or autoimmune context. This is biological context, not study-specific reactivity.

  • They are also capable of eliciting spontaneous humoral and cellular immune responses in cancer patients, and are potentially useful targets in cancer vaccine-based immunotherapy.

Canonical record: https://seroatlas.com/gene/SSX3. 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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