Gene Symbol: Kcnmb4
Description: potassium calcium-activated channel subfamily M regulatory beta subunit 4
Alias: calcium-activated potassium channel subunit beta-4, BK channel subunit beta-4, BKbeta4, calcium activated potassium channel beta 4 subunit, calcium-activated potassium channel, subfamily M subunit beta-4, charybdotoxin receptor subunit beta-4, k(VCA)beta-4, maxi K channel subunit beta-4, potassium channel subfamily M regulatory beta subunit 4, potassium large conductance calcium-activated channel, subfamily M, beta member 4, slo-beta-4
Species: rat
Products:     Kcnmb4

Top Publications

  1. Berkefeld H, Sailer C, Bildl W, Rohde V, Thumfart J, Eble S, et al. BKCa-Cav channel complexes mediate rapid and localized Ca2+-activated K+ signaling. Science. 2006;314:615-20 pubmed
    ..Complex formation with distinct Cav channels enables BKCa-mediated membrane hyperpolarization that controls neuronal firing pattern and release of hormones and transmitters in the central nervous system. ..
  2. Morimoto T, Sakamoto K, Sade H, Ohya S, Muraki K, Imaizumi Y. Voltage-sensitive oxonol dyes are novel large-conductance Ca2+-activated K+ channel activators selective for beta1 and beta4 but not for beta2 subunits. Mol Pharmacol. 2007;71:1075-88 pubmed
    ..These findings provide a molecular and structural basis for understanding the regulatory mechanism of BK channel activity by an auxiliary beta subunit and will be fundamental to the development of beta-selective BK channel openers. ..
  3. Cheng Y, Gu X, Bednarczyk P, Wiedemann F, Haddad G, Siemen D. Hypoxia increases activity of the BK-channel in the inner mitochondrial membrane and reduces activity of the permeability transition pore. Cell Physiol Biochem. 2008;22:127-36 pubmed publisher
    ..We therefore conclude that there is interaction between the mtBK and the PTP in a way that an open mtBK keeps the PTP closed. Thus, the response of mitochondrial ion channels to hypoxia could be interpreted as anti-apoptotic. ..
  4. Wynne P, Puig S, Martin G, Treistman S. Compartmentalized beta subunit distribution determines characteristics and ethanol sensitivity of somatic, dendritic, and terminal large-conductance calcium-activated potassium channels in the rat central nervous system. J Pharmacol Exp Ther. 2009;329:978-86 pubmed publisher
    ..This hypothesis is supported immunohistochemically by the appearance of distinct punctate beta1 or beta4 channel clusters in the membrane of somatic and dendritic or nerve terminal compartments, respectively. ..
  5. Seidel K, Derst C, Salzmann M, Höltje M, Priller J, Markgraf R, et al. Expression of the voltage- and Ca2+-dependent BK potassium channel subunits BK?1 and BK?4 in rodent astrocytes. Glia. 2011;59:893-902 pubmed publisher
    ..Thus, BK?4 expression in astrocytes likely participates in regulating astrocytic voltage gradients and maintaining K(+) homeostasis, hence enabling astrocytes to fulfill their complex regulatory influence on proper brain function. ..
  6. Petrik D, Wang B, Brenner R. Modulation by the BK accessory ?4 subunit of phosphorylation-dependent changes in excitability of dentate gyrus granule neurons. Eur J Neurosci. 2011;34:695-704 pubmed publisher
    ..By opposing BK channel activation, the ?4 subunit plays an important role in moderating firing frequency regardless of changes in phosphorylation status. ..
  7. Brenner R, Jegla T, Wickenden A, Liu Y, Aldrich R. Cloning and functional characterization of novel large conductance calcium-activated potassium channel beta subunits, hKCNMB3 and hKCNMB4. J Biol Chem. 2000;275:6453-61 pubmed
    ..These results suggest that beta subunits in diverse tissue types fine-tune slo channel properties to the needs of a particular cell. ..
  8. Weiger T, Holmqvist M, Levitan I, Clark F, Sprague S, Huang W, et al. A novel nervous system beta subunit that downregulates human large conductance calcium-dependent potassium channels. J Neurosci. 2000;20:3563-70 pubmed
    ..beta4 may be important for the critical roles played by Slowpoke channels in the regulation of neuronal excitability and neurotransmitter release. ..
  9. Nehrke K, Quinn C, Begenisich T. Molecular identification of Ca2+-activated K+ channels in parotid acinar cells. Am J Physiol Cell Physiol. 2003;284:C535-46 pubmed
    ..RT-PCR analysis revealed the presence of two mSlo beta-subunits (Kcnmb1 and Kcnmb4) in parotid tissue...

More Information


  1. Piwonska M, Wilczek E, Szewczyk A, Wilczynski G. Differential distribution of Ca2+-activated potassium channel beta4 subunit in rat brain: immunolocalization in neuronal mitochondria. Neuroscience. 2008;153:446-60 pubmed publisher
    ..directed against four distinct beta subunits demonstrated the presence of the BK(Ca) channel beta4 subunit (KCNMB4) in the inner membrane of neuronal mitochondria in the rat brain and cultured neurons...
  2. Cox N, Toro B, Pacheco Otalora L, Garrido Sanabria E, Zarei M. An endoplasmic reticulum trafficking signal regulates surface expression of ?4 subunit of a voltage- and Ca²?-activated K? channel. Brain Res. 2014;1553:12-23 pubmed publisher
    ..Removal of ?4 retention signal increases its surface expression that may lead to reduction of the MaxiK channel activity and neuronal excitability...
  3. Noursadeghi E, Jafari A, Saghiri R, Sauve R, Eliassi A. Impairment of brain mitochondrial charybdotoxin- and ATP-insensitive BK channel activities in diabetes. Neuromolecular Med. 2014;16:862-71 pubmed publisher