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AliasesKCNMB1, BKbeta1, K(VCA)beta, SLO-BETA, hbeta1, hslo-beta, k(VCA)beta-1, slo-beta-1, potassium calcium-activated channel subfamily M regulatory beta subunit 1
External IDsMGI: 1334203 HomoloGene: 3054 GeneCards: KCNMB1
Gene location (Human)
Chromosome 5 (human)
Chr.Chromosome 5 (human)[1]
Chromosome 5 (human)
Genomic location for KCNMB1
Genomic location for KCNMB1
Band5q35.1Start170,374,671 bp[1]
End170,389,634 bp[1]
RNA expression pattern
PBB GE KCNMB1 209948 at fs.png
More reference expression data
RefSeq (mRNA)



RefSeq (protein)



Location (UCSC)Chr 5: 170.37 – 170.39 MbChr 11: 33.96 – 33.97 Mb
PubMed search[3][4]
View/Edit HumanView/Edit Mouse

Calcium-activated potassium channel subunit beta-1 is a protein that in humans is encoded by the KCNMB1 gene.[5][6][7]


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 product of this gene, the modulatory beta subunit. Intracellular calcium regulates the physical association between the alpha and beta subunits.[7] Beta subunits (beta 1-4) are highly tissue specific in their expression, with beta-1 being present predominantly on vascular smooth muscle. Endothelial cells are not known to express beta-1 subunits. Beta-1 is also known to be expressed in urinary bladder and in some regions of the brain. Association of the beta-1 subunit with the BK channel increases the apparent Ca2+ sensitivity of the channel and decreases voltage dependence.[8]

See also[edit]


  1. ^ a b c GRCh38: Ensembl release 89: ENSG00000145936 - Ensembl, May 2017
  2. ^ a b c GRCm38: Ensembl release 89: ENSMUSG00000020155 - Ensembl, May 2017
  3. ^ "Human PubMed Reference:".
  4. ^ "Mouse PubMed Reference:".
  5. ^ Tseng-Crank J, Godinot N, Johansen TE, Ahring PK, Strøbaek D, Mertz R, Foster CD, Olesen SP, Reinhart PH (Aug 1996). "Cloning, expression, and distribution of a Ca(2+)-activated K+ channel beta-subunit from human brain". Proceedings of the National Academy of Sciences of the United States of America. 93 (17): 9200–5. doi:10.1073/pnas.93.17.9200. PMC 38619. PMID 8799178.
  6. ^ Jiang Z, Wallner M, Meera P, Toro L (Jan 1999). "Human and rodent MaxiK channel beta-subunit genes: cloning and characterization". Genomics. 55 (1): 57–67. doi:10.1006/geno.1998.5627. PMID 9888999.
  7. ^ a b "Entrez Gene: KCNMB1 potassium large conductance calcium-activated channel, subfamily M, beta member 1".
  8. ^ Tano, J.-Y.; Gollasch, M. (2014). "Hypoxia and ischemia-reperfusion: a BiK contribution?". AJP: Heart and Circulatory Physiology. 307 (6): H811–H817. doi:10.1152/ajpheart.00319.2014. ISSN 0363-6135.

Further reading[edit]

This article incorporates text from the United States National Library of Medicine, which is in the public domain.