Seroatlas · Human Serome Atlas

COL9A2

Collagen alpha-2(IX) chain

Also known as: CO9A2_HUMAN, EDM2, MED

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

Protein identityUniProt · HPA

UniProt accession
Q14055
Gene
COL9A2
Ensembl
ENSG00000049089
Chromosome
1
Canonical length
689 aa
Protein class
Disease related genes, Human disease related genes, Plasma proteins, Predicted intracellular proteins, Predicted secreted proteins
Subcellular location
Vesicles
Secretome location
Secreted to extracellular matrix

OverviewNCBI Gene

This gene encodes one of the three alpha chains of type IX collagen, the major collagen component of hyaline cartilage. Type IX collagen, a heterotrimeric molecule, is usually found in tissues containing type II collagen, a fibrillar collagen. This chain is unusual in that, unlike the other two type IX alpha chains, it contains a covalently attached glycosaminoglycan side chain. Mutations in this gene are associated with multiple epiphyseal dysplasia. [provided by RefSeq, Jul 2008]

Canonical amino-acid sequenceUniProt

689 residues, UniProt reviewed canonical sequence.

>Q14055|COL9A2
     1  MAAATASPRS LLVLLQVVVL ALAQIRGPPG ERGPPGPPGP PGVPGSDGID GDNGPPGKAG
    61  PPGPKGEPGK AGPDGPDGKP GIDGLTGAKG EPGPMGIPGV KGQPGLPGPP GLPGPGFAGP
   121  PGPPGPVGLP GEIGIRGPKG DPGPDGPSGP PGPPGKPGRP GTIQGLEGSA DFLCPTNCPP
   181  GMKGPPGLQG VKGHAGKRGI LGDPGHQGKP GPKGDVGASG EQGIPGPPGP QGIRGYPGMA
   241  GPKGETGPHG YKGMVGAIGA TGPPGEEGPR GPPGRAGEKG DEGSPGIRGP QGITGPKGAT
   301  GPPGINGKDG TPGTPGMKGS AGQAGQPGSP GHQGLAGVPG QPGTKGGPGD QGEPGPQGLP
   361  GFSGPPGKEG EPGPRGEIGP QGIMGQKGDQ GERGPVGQPG PQGRQGPKGE QGPPGIPGPQ
   421  GLPGVKGDKG SPGKTGPRGK VGDPGVAGLP GEKGEKGESG EPGPKGQQGV RGEPGYPGPS
   481  GDAGAPGVQG YPGPPGPRGL AGNRGVPGQP GRQGVEGRDA TDQHIVDVAL KMLQEQLAEV
   541  AVSAKREALG AVGMMGPPGP PGPPGYPGKQ GPHGHPGPRG VPGIVGAVGQ IGNTGPKGKR
   601  GEKGDPGEVG RGHPGMPGPP GIPGLPGRPG QAINGKDGDR GSPGAPGEAG RPGLPGPVGL
   661  PGFCEPAACL GASAYASARL TEPGSIKGP

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against COL9A2 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
Secreted
Secreted
Yes
Transmembrane segments
0
Mean surface accessibility (rSASA)
0.7
Highest tissue expression
136 nTPM

Expression across tissuesHPA

Tissue

  • spinal cord: 136 nTPM
  • midbrain: 114 nTPM
  • pituitary gland: 106 nTPM
  • hippocampal formation: 73 nTPM
  • basal ganglia: 69 nTPM
  • amygdala: 62 nTPM

Single-cell type

  • müller glia: 425 nCPM
  • thyrotrophs: 179 nCPM
  • epididymal clear cells: 167 nCPM
  • oligodendrocytes: 137 nCPM
  • oligodendrocyte progenitor cells: 124 nCPM
  • somatotrophs: 107 nCPM

Immune cell

  • eosinophil: 3.2 nTPM
  • myeloid DC: 1.2 nTPM
  • neutrophil: 0.5 nTPM
  • non-classical monocyte: 0.3 nTPM
  • intermediate monocyte: 0.2 nTPM
  • memory B-cell: 0.2 nTPM

Brain region

  • white matter: 144 nTPM
  • midbrain: 122 nTPM
  • basal ganglia: 116 nTPM
  • medulla oblongata: 106 nTPM
  • pons: 105 nTPM
  • cerebellum: 90 nTPM

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about COL9A2.

Disease | AllUniProt

Conditions COL9A2 is implicated in, by any mechanism.

Disease | GeneticClinVar

57 pathogenic / likely-pathogenic of 1,325 ClinVar records.

Conditions with pathogenic or likely-pathogenic variants.

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)
0.64
gnomAD pLI
0
gnomAD missense Z
1.34
DepMap mean gene effect
-0.01
DepMap dependency class
selective

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

Molecular functions

Cellular components

Protein domainsUniProt · Pfam · InterPro

KeywordsUniProt

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads COL9A2 as an antibody target. Whether an autoantibody or antibody against COL9A2 could matter depends on whether native COL9A2 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

COL9A2 is annotated as secreted, so native COL9A2 circulates and is directly accessible to antibodies. Secreted and cell-surface proteins are the autoantibody targets most likely to act like drugs, blocking or depleting the native protein.

Annotation status

The present source text does not explicitly label COL9A2 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/COL9A2. 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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