Seroatlas · Human Serome Atlas

CSAG1

Chondrosarcoma-associated gene 1 protein

Also known as: CSAG1_HUMAN, CSAGE, CT24.1

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

Protein identityUniProt · HPA

UniProt accession
Q6PB30
Gene
CSAG1
Ensembl
ENSG00000198930
Chromosome
X
Canonical length
78 aa
Protein class
Predicted intracellular proteins

OverviewNCBI Gene

This gene encodes a member of a family of tumor antigens. The protein is expressed in chondrosarcomas, but may also be expressed in normal tissues such as testis. Alternative splicing of this gene results in two transcript variants encoding the same protein. [provided by RefSeq, Jul 2008]

Canonical amino-acid sequenceUniProt

78 residues, UniProt reviewed canonical sequence.

>Q6PB30|CSAG1
     1  MSATTACWPA FTVLGEARGD QVDWSRLYRD TGLVKMSRKP RASSPFSNNH PSTPKRFPRQ
    61  PRREKGPVKE VPGTKGSP

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against CSAG1 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)
0.68
Highest tissue expression
1.9 nTPM

Expression across tissuesHPA

Tissue

  • basal ganglia: 1.9 nTPM
  • cerebral cortex: 1.4 nTPM
  • hippocampal formation: 1.4 nTPM
  • midbrain: 1.4 nTPM
  • amygdala: 1.3 nTPM
  • testis: 1.2 nTPM

Single-cell type

  • differentiating spermatogonia: 11 nCPM
  • undifferentiated spermatogonia: 8.7 nCPM
  • gastric progenitor cells: 6.4 nCPM
  • early primary spermatocytes: 5.5 nCPM
  • pericytes: 2.6 nCPM
  • b-cells: 0.4 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

  • cerebral cortex: 1.4 nTPM
  • amygdala: 0.9 nTPM
  • pons: 0.9 nTPM
  • white matter: 0.8 nTPM
  • medulla oblongata: 0.7 nTPM
  • midbrain: 0.6 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)
1.92
gnomAD pLI
0
gnomAD missense Z
-1.04
DepMap mean gene effect
0.24
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

Cellular components

KeywordsUniProt

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads CSAG1 as an antibody target. Whether an autoantibody or antibody against CSAG1 could matter depends on whether native CSAG1 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

CSAG1 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 CSAG1 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/CSAG1. 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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