Seroatlas · Human Serome Atlas

CA9

Carbonic anhydrase 9

Also known as: CAH9_HUMAN, CAIX, MN

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

Protein identityUniProt · HPA

UniProt accession: Q16790
Gene: CA9
Ensembl: ENSG00000107159
Chromosome: 9
Canonical length: 459 aa
Protein class: Enzymes, FDA approved drug targets, Metabolic proteins, Predicted membrane proteins, Transporters
Subcellular location: Plasma membrane

OverviewNCBI Gene

Carbonic anhydrases (CAs) are a large family of zinc metalloenzymes that catalyze the reversible hydration of carbon dioxide. They participate in a variety of biological processes, including respiration, calcification, acid-base balance, bone resorption, and the formation of aqueous humor, cerebrospinal fluid, saliva, and gastric acid. They show extensive diversity in tissue distribution and in their subcellular localization. CA IX is a transmembrane protein and is one of only two tumor-associated carbonic anhydrase isoenzymes known. It is expressed in all clear-cell renal cell carcinoma, but is not detected in normal kidney or most other normal tissues. It may be involved in cell proliferation and transformation. This gene was mapped to 17q21.2 by fluorescence in situ hybridization, however, radiation hybrid mapping localized it to 9p13-p12. [provided by RefSeq, Jun 2014]

Canonical amino-acid sequenceUniProt

459 residues, UniProt reviewed canonical sequence.

>Q16790|CA9
     1  MAPLCPSPWL PLLIPAPAPG LTVQLLLSLL LLVPVHPQRL PRMQEDSPLG GGSSGEDDPL
    61  GEEDLPSEED SPREEDPPGE EDLPGEEDLP GEEDLPEVKP KSEEEGSLKL EDLPTVEAPG
   121  DPQEPQNNAH RDKEGDDQSH WRYGGDPPWP RVSPACAGRF QSPVDIRPQL AAFCPALRPL
   181  ELLGFQLPPL PELRLRNNGH SVQLTLPPGL EMALGPGREY RALQLHLHWG AAGRPGSEHT
   241  VEGHRFPAEI HVVHLSTAFA RVDEALGRPG GLAVLAAFLE EGPEENSAYE QLLSRLEEIA
   301  EEGSETQVPG LDISALLPSD FSRYFQYEGS LTTPPCAQGV IWTVFNQTVM LSAKQLHTLS
   361  DTLWGPGDSR LQLNFRATQP LNGRVIEASF PAGVDSSPRA AEPVQLNSCL AAGDILALVF
   421  GLLFAVTSVA FLVQMRRQHR RGTKGGVSYR PAEVAETGA

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against CA9 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: Cell surface
Secreted: No
Transmembrane segments: 1
Mean surface accessibility (rSASA): 0.44
Highest tissue expression: 294 nTPM

Expression across tissuesHPA

Tissue

stomach: 294 nTPM
gallbladder: 23 nTPM
cerebellum: 17 nTPM
duodenum: 14 nTPM
small intestine: 13 nTPM
skin: 8.5 nTPM

Single-cell type

early spermatids: 335 nCPM
gastric chief cells: 287 nCPM
parietal cells: 108 nCPM
foveolar cells: 83 nCPM
mucous neck cells: 80 nCPM
cholangiocytes: 55 nCPM

Immune cell

plasmacytoid DC: 0.1 nTPM
basophil: 0 nTPM
classical monocyte: 0 nTPM
eosinophil: 0 nTPM
gdT-cell: 0 nTPM
intermediate monocyte: 0 nTPM

Brain region

cerebellum: 12 nTPM
cerebral cortex: 1.3 nTPM
thalamus: 1.1 nTPM
hippocampal formation: 0.6 nTPM
pons: 0.6 nTPM
midbrain: 0.4 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): 1.09
gnomAD pLI: 0
gnomAD missense Z: 0.11
DepMap mean gene effect: -0.03
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

InteractionsUniProt · HPA

Protein binding partners of CA9 in the human serome: UniProt-annotated complex subunits plus reported interactors. Each links to its own Seroatlas record.

GLRX3

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads CA9 as an antibody target. Whether an autoantibody or antibody against CA9 could matter depends on whether native CA9 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

CA9 is annotated at the cell surface, where native CA9 is exposed to circulating antibodies and is a prime autoantibody target that could block, deplete, or overstimulate it.

Annotation status

The present source text does not explicitly label CA9 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

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