Seroatlas · Human Serome Atlas

KCNMB4

Calcium-activated potassium channel subunit beta-4

Also known as: KCMB4_HUMAN

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

Protein identityUniProt · HPA

UniProt accession
Q86W47
Gene
KCNMB4
Ensembl
ENSG00000135643
Chromosome
12
Canonical length
210 aa
Protein class
FDA approved drug targets, Predicted membrane proteins
Subcellular location
Cytosol

OverviewNCBI Gene

MaxiK channels are large conductance, voltage and calcium-sensitive potassium channels which are fundamental to the control of smooth muscle tone and neuronal excitability. MaxiK channels can be formed by 2 subunits: the pore-forming alpha subunit and the modulatory beta subunit. The protein encoded by this gene is an auxiliary beta subunit which slows activation kinetics, leads to steeper calcium sensitivity, and shifts the voltage range of current activation to more negative potentials than does the beta 1 subunit. [provided by RefSeq, Jul 2008]

Canonical amino-acid sequenceUniProt

210 residues, UniProt reviewed canonical sequence.

>Q86W47|KCNMB4
     1  MAKLRVAYEY TEAEDKSIRL GLFLIISGVV SLFIFGFCWL SPALQDLQAT EANCTVLSVQ
    61  QIGEVFECTF TCGADCRGTS QYPCVQVYVN NSESNSRALL HSDEHQLLTN PKCSYIPPCK
   121  RENQKNLESV MNWQQYWKDE IGSQPFTCYF NQHQRPDDVL LHRTHDEIVL LHCFLWPLVT
   181  FVVGVLIVVL TICAKSLAVK AEAMKKRKFS

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against KCNMB4 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
2
Mean surface accessibility (rSASA)
0.34
Highest tissue expression
38 nTPM

Expression across tissuesHPA

Tissue

  • hippocampal formation: 38 nTPM
  • amygdala: 29 nTPM
  • cerebral cortex: 28 nTPM
  • spinal cord: 27 nTPM
  • midbrain: 25 nTPM
  • basal ganglia: 24 nTPM

Single-cell type

  • schwann cells: 642 nCPM
  • oligodendrocytes: 250 nCPM
  • brain excitatory neurons: 118 nCPM
  • retinal bipolar cells: 101 nCPM
  • renal collecting duct principal cells: 92 nCPM
  • ependymal cells: 90 nCPM

Immune cell

  • naive CD8 T-cell: 0.6 nTPM
  • naive CD4 T-cell: 0.4 nTPM
  • naive B-cell: 0.3 nTPM
  • basophil: 0.1 nTPM
  • memory B-cell: 0.1 nTPM
  • memory CD4 T-cell: 0.1 nTPM

Brain region

  • white matter: 77 nTPM
  • cerebral cortex: 57 nTPM
  • basal ganglia: 47 nTPM
  • medulla oblongata: 46 nTPM
  • thalamus: 45 nTPM
  • amygdala: 39 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)
0.34
gnomAD pLI
0.94
gnomAD missense Z
2.06
DepMap mean gene effect
-0.1
DepMap dependency class
selective

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 6% 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 KCNMB4 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 KCNMB4 as an antibody target. Whether an autoantibody or antibody against KCNMB4 could matter depends on whether native KCNMB4 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

KCNMB4 is annotated at the cell surface, where native KCNMB4 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 KCNMB4 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/KCNMB4. 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).

© 2026 · Seroatlas, Discover Oregon LLC · Terms of use

Loading the interactive Seroatlas protein explorer...