Seroatlas · Human Serome Atlas

KCNN4

Intermediate conductance calcium-activated potassium channel protein 4

Also known as: hIKCa1, hKCa4, hSK4, IK, KCa3.1, KCNN4_HUMAN

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

Protein identityUniProt · HPA

UniProt accession
O15554
Gene
KCNN4
Ensembl
ENSG00000104783
Chromosome
19
Canonical length
427 aa
Protein class
Disease related genes, FDA approved drug targets, Human disease related genes, Predicted intracellular proteins, Predicted membrane proteins, Transporters, Voltage-gated ion channels
Subcellular location
Plasma membrane,Cytosol
Quaternary structure
Homotetramer

OverviewNCBI Gene

The protein encoded by this gene is part of a potentially heterotetrameric voltage-independent potassium channel that is activated by intracellular calcium. Activation is followed by membrane hyperpolarization, which promotes calcium influx. The encoded protein may be part of the predominant calcium-activated potassium channel in T-lymphocytes. This gene is similar to other KCNN family potassium channel genes, but it differs enough to possibly be considered as part of a new subfamily. [provided by RefSeq, Jul 2008]

Canonical amino-acid sequenceUniProt

427 residues, UniProt reviewed canonical sequence.

>O15554|KCNN4
     1  MGGDLVLGLG ALRRRKRLLE QEKSLAGWAL VLAGTGIGLM VLHAEMLWFG GCSWALYLFL
    61  VKCTISISTF LLLCLIVAFH AKEVQLFMTD NGLRDWRVAL TGRQAAQIVL ELVVCGLHPA
   121  PVRGPPCVQD LGAPLTSPQP WPGFLGQGEA LLSLAMLLRL YLVPRAVLLR SGVLLNASYR
   181  SIGALNQVRF RHWFVAKLYM NTHPGRLLLG LTLGLWLTTA WVLSVAERQA VNATGHLSDT
   241  LWLIPITFLT IGYGDVVPGT MWGKIVCLCT GVMGVCCTAL LVAVVARKLE FNKAEKHVHN
   301  FMMDIQYTKE MKESAARVLQ EAWMFYKHTR RKESHAARRH QRKLLAAINA FRQVRLKHRK
   361  LREQVNSMVD ISKMHMILYD LQQNLSSSHR ALEKQIDTLA GKLDALTELL STALGPRQLP
   421  EPSQQSK

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against KCNN4 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)
0.38
Highest tissue expression
119 nTPM

Expression across tissuesHPA

Tissue

  • salivary gland: 119 nTPM
  • stomach: 31 nTPM
  • skin: 28 nTPM
  • prostate: 26 nTPM
  • small intestine: 24 nTPM
  • spleen: 20 nTPM

Single-cell type

  • syncytiotrophoblasts: 995 nCPM
  • breast lactating cells: 307 nCPM
  • cytotrophoblasts: 282 nCPM
  • migrating cytotrophoblasts: 160 nCPM
  • breast secretory cells: 107 nCPM
  • salivary acinar cells: 91 nCPM

Immune cell

  • memory B-cell: 36 nTPM
  • intermediate monocyte: 33 nTPM
  • myeloid DC: 29 nTPM
  • naive B-cell: 21 nTPM
  • classical monocyte: 20 nTPM
  • non-classical monocyte: 19 nTPM

Brain region

  • white matter: 3.2 nTPM
  • thalamus: 2.7 nTPM
  • spinal cord: 2.2 nTPM
  • basal ganglia: 2 nTPM
  • hypothalamus: 2 nTPM
  • pons: 2 nTPM

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about KCNN4.

Disease | AllUniProt

Conditions KCNN4 is implicated in, by any mechanism.

  • Dehydrated hereditary stomatocytosis 2 (DHS2) MIM:616689

Disease | GeneticClinVar

4 pathogenic / likely-pathogenic of 174 ClinVar records.

Conditions with pathogenic or likely-pathogenic variants.

  • Dehydrated hereditary stomatocytosis 2
  • Inborn genetic diseases
  • Dehydrated hereditary stomatocytosis with or without pseudohyperkalemia and/or perinatal edema

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)
1.01
gnomAD pLI
0
gnomAD missense Z
1.62
DepMap mean gene effect
0.15
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

Molecular functions

Cellular components

Protein domainsUniProt · Pfam · InterPro

KeywordsUniProt

InteractionsUniProt · HPA

Protein binding partners of KCNN4 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 KCNN4 as an antibody target. Whether an autoantibody or antibody against KCNN4 could matter depends on whether native KCNN4 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

KCNN4 is annotated at the cell surface, where native KCNN4 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 KCNN4 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/KCNN4. 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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