Seroatlas · Human Serome Atlas

SPANXN3

Sperm protein associated with the nucleus on the X chromosome N3

Also known as: CT11.8, SPANX-N3, SPXN3_HUMAN

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

Protein identityUniProt · HPA

UniProt accession
Q5MJ09
Gene
SPANXN3
Ensembl
ENSG00000189252
Chromosome
X
Canonical length
141 aa
Protein class
Predicted intracellular proteins
Subcellular location
Nucleoplasm,Nucleoli fibrillar center

OverviewNCBI Gene

No narrative summary is available for SPANXN3 in this catalog release; identity and structured annotations are shown without generated factual claims.

Canonical amino-acid sequenceUniProt

141 residues, UniProt reviewed canonical sequence.

>Q5MJ09|SPANXN3
     1  MEQPTSSTNG EKTKSPCESN NKKNDEMQEV PNRVLAPEQS LKNTKTSEYP IIFVYYLRKG
    61  KKINSNQLEN EQSQENSINP IQKEEDEGVD LSEGSSNEDE DLGPCEGPSK EDKDLDSSEG
   121  SSQEDEDLGL SEGSSQDSGE D

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against SPANXN3 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)
0.72
Highest tissue expression
47 nTPM

Expression across tissuesHPA

Tissue

  • testis: 47 nTPM
  • duodenum: 0.8 nTPM
  • small intestine: 0.4 nTPM
  • adipose tissue: 0 nTPM
  • adrenal gland: 0 nTPM
  • amygdala: 0 nTPM

Single-cell type

  • early spermatids: 476 nCPM
  • late primary spermatocytes: 332 nCPM
  • late spermatids: 317 nCPM
  • sertoli cells: 3.1 nCPM
  • leydig cells: 2.2 nCPM
  • differentiating spermatogonia: 0.9 nCPM

Immune cell

  • basophil: 0 nTPM
  • classical monocyte: 0 nTPM
  • eosinophil: 0 nTPM
  • gdT-cell: 0 nTPM
  • intermediate monocyte: 0 nTPM
  • MAIT T-cell: 0 nTPM

Brain region

  • midbrain: 0.2 nTPM
  • amygdala: 0.1 nTPM
  • cerebral cortex: 0.1 nTPM
  • hypothalamus: 0.1 nTPM
  • pons: 0.1 nTPM
  • white matter: 0.1 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)
1.75
gnomAD pLI
0.38
gnomAD missense Z
-0.19
DepMap mean gene effect
-0.12
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

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads SPANXN3 as an antibody target. Whether an autoantibody or antibody against SPANXN3 could matter depends on whether native SPANXN3 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

SPANXN3 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 SPANXN3 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/SPANXN3. 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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