Seroatlas · Human Serome Atlas

AQP9

Aquaporin-9

Also known as: AQP9_HUMAN, HsT17287, SSC1

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

Protein identityUniProt · HPA

UniProt accession
O43315
Gene
AQP9
Ensembl
ENSG00000103569
Chromosome
15
Canonical length
295 aa
Protein class
Metabolic proteins, Predicted membrane proteins, Transporters
Subcellular location
Mid piece
Quaternary structure
Homotetramer

OverviewNCBI Gene

The aquaporins are a family of water-selective membrane channels. This gene encodes a member of a subset of aquaporins called the aquaglyceroporins. This protein allows passage of a broad range of noncharged solutes and also stimulates urea transport and osmotic water permeability. This protein may also facilitate the uptake of glycerol in hepatic tissue . The encoded protein may also play a role in specialized leukocyte functions such as immunological response and bactericidal activity. Alternate splicing results in multiple transcript variants. [provided by RefSeq, Mar 2016]

Canonical amino-acid sequenceUniProt

295 residues, UniProt reviewed canonical sequence.

>O43315|AQP9
     1  MQPEGAEKGK SFKQRLVLKS SLAKETLSEF LGTFILIVLG CGCVAQAILS RGRFGGVITI
    61  NVGFSMAVAM AIYVAGGVSG GHINPAVSLA MCLFGRMKWF KLPFYVGAQF LGAFVGAATV
   121  FGIYYDGLMS FAGGKLLIVG ENATAHIFAT YPAPYLSLAN AFADQVVATM ILLIIVFAIF
   181  DSRNLGAPRG LEPIAIGLLI IVIASSLGLN SGCAMNPARD LSPRLFTALA GWGFEVFRAG
   241  NNFWWIPVVG PLVGAVIGGL IYVLVIEIHH PEPDSVFKTE QSEDKPEKYE LSVIM

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against AQP9 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
6
Mean surface accessibility (rSASA)
0.31
Highest tissue expression
657 nTPM

Expression across tissuesHPA

Tissue

  • liver: 657 nTPM
  • appendix: 69 nTPM
  • bone marrow: 64 nTPM
  • spleen: 43 nTPM
  • epididymis: 41 nTPM
  • urinary bladder: 30 nTPM

Single-cell type

  • neutrophils: 8,995 nCPM
  • monocytes: 959 nCPM
  • hepatocytes: 441 nCPM
  • epididymal basal cells: 152 nCPM
  • epididymal efferent duct absorptive cells: 146 nCPM
  • epididymal clear cells: 133 nCPM

Immune cell

  • neutrophil: 1,166 nTPM
  • classical monocyte: 59 nTPM
  • non-classical monocyte: 23 nTPM
  • total PBMC: 19 nTPM
  • intermediate monocyte: 18 nTPM
  • myeloid DC: 1.8 nTPM

Brain region

  • cerebral cortex: 28 nTPM
  • thalamus: 14 nTPM
  • pons: 7.4 nTPM
  • hippocampal formation: 6 nTPM
  • basal ganglia: 1.5 nTPM
  • cerebellum: 1.3 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)
0.66
gnomAD pLI
0.24
gnomAD missense Z
-1.21
DepMap mean gene effect
-0.04
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

Molecular functions

Cellular components

Protein domainsUniProt · Pfam · InterPro

KeywordsUniProt

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads AQP9 as an antibody target. Whether an autoantibody or antibody against AQP9 could matter depends on whether native AQP9 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

AQP9 is annotated at the cell surface, where native AQP9 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 AQP9 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/AQP9. 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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