Seroatlas · Human Serome Atlas

KCNK9

Potassium channel subfamily K member 9

Also known as: K2p9.1, KCNK9_HUMAN, TASK-3, TASK3

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

Protein identityUniProt · HPA

UniProt accession
Q9NPC2
Gene
KCNK9
Ensembl
ENSG00000169427
Chromosome
8
Canonical length
374 aa
Protein class
Disease related genes, FDA approved drug targets, Human disease related genes, Predicted membrane proteins, Transporters, Voltage-gated ion channels
Subcellular location
Plasma membrane
Quaternary structure
Homodimer

OverviewNCBI Gene

This gene encodes a protein that contains multiple transmembrane regions and two pore-forming P domains and functions as a pH-dependent potassium channel. Amplification and overexpression of this gene have been observed in several types of human carcinomas. This gene is imprinted in the brain, with preferential expression from the maternal allele. A mutation in this gene was associated with Birk-Barel dysmorphism syndrome. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Jul 2017]

Canonical amino-acid sequenceUniProt

374 residues, UniProt reviewed canonical sequence.

>Q9NPC2|KCNK9
     1  MKRQNVRTLS LIVCTFTYLL VGAAVFDALE SDHEMREEEK LKAEEIRIKG KYNISSEDYR
    61  QLELVILQSE PHRAGVQWKF AGSFYFAITV ITTIGYGHAA PGTDAGKAFC MFYAVLGIPL
   121  TLVMFQSLGE RMNTFVRYLL KRIKKCCGMR NTDVSMENMV TVGFFSCMGT LCIGAAAFSQ
   181  CEEWSFFHAY YYCFITLTTI GFGDYVALQT KGALQKKPLY VAFSFMYILV GLTVIGAFLN
   241  LVVLRFLTMN SEDERRDAEE RASLAGNRNS MVIHIPEEPR PSRPRYKADV PDLQSVCSCT
   301  CYRSQDYGGR SVAPQNSFSA KLAPHYFHSI SYKIEEISPS TLKNSLFPSP ISSISPGLHS
   361  FTDHQRLMKR RKSV

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against KCNK9 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
4
Mean surface accessibility (rSASA)
0.46
Highest tissue expression
7.4 nTPM

Expression across tissuesHPA

Tissue

  • cerebellum: 7.4 nTPM
  • adrenal gland: 1.5 nTPM
  • cerebral cortex: 1 nTPM
  • pituitary gland: 0.7 nTPM
  • blood vessel: 0.5 nTPM
  • colon: 0.5 nTPM

Single-cell type

  • oocytes: 74 nCPM
  • adrenal medulla cells: 53 nCPM
  • brain excitatory neurons: 46 nCPM
  • thyrotrophs: 31 nCPM
  • retinal amacrine cells: 27 nCPM
  • other brain neurons: 15 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

  • cerebellum: 20 nTPM
  • cerebral cortex: 6.6 nTPM
  • pons: 5.1 nTPM
  • midbrain: 4 nTPM
  • white matter: 3.9 nTPM
  • medulla oblongata: 3.6 nTPM

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about KCNK9.

Disease | AllUniProt

Conditions KCNK9 is implicated in, by any mechanism.

Disease | GeneticClinVar

8 pathogenic / likely-pathogenic of 86 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)
0.31
gnomAD pLI
0.96
gnomAD missense Z
2.9
DepMap mean gene effect
-0.05
DepMap dependency class
selective

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 5% 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 KCNK9 in the human serome: UniProt-annotated complex subunits plus reported interactors. Each links to its own Seroatlas record.

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads KCNK9 as an antibody target. Whether an autoantibody or antibody against KCNK9 could matter depends on whether native KCNK9 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

KCNK9 is annotated at the cell surface, where native KCNK9 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 KCNK9 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/KCNK9. 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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