KCNMB2
| KCNMB2, ball and chain domain | |||||||||
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 solution structure of the cytoplasmic n-terminus of the bk beta-subunit kcnmb2 | |||||||||
| Identifiers | |||||||||
| Symbol | KcnmB2_inactiv | ||||||||
| Pfam | PF09303 | ||||||||
| InterPro | IPR015382 | ||||||||
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Calcium-activated potassium channel subunit beta-2 is a protein that in humans is encoded by the KCNMB2 gene.[1][2]
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 contain two distinct subunits: a pore-forming alpha subunit and a modulatory beta subunit. Each complete MaxiK channel contains four copies of the pore-forming alpha subunit and up to four beta subunits. The protein encoded by the KCNMB2 gene is an auxiliary beta subunit which influences the calcium sensitivity of MaxiK currents and, following activation of MaxiK current, causes persistent inactivation. The subunit encoded by the KCNMB2 gene is expressed in various endocrine cells, including pancreas and adrenal chromaffin cells. It is also found in the brain, including the hippocampus. The KCNMB2 gene is homologous to three other genes found in mammalian genomes: KCNMB1 (found primarily in smooth muscle), KCNMB3, and KCNMB4 (the primary brain MaxiK auxiliary subunit).[2]
Calcium-activated potassium channel subunit beta-2 comprises two domains. An N-terminal cytoplasmic domain, the ball and chain domain, which is responsible for the fast inactivation of these channels,[3] and a C-terminal calcium-activated potassium channel beta subunit domain. The N-terminal domain only occurs in calcium-activated potassium channel subunit beta-2, while the C-terminal domain is found in related proteins.
See also
References
- ^ Wallner M, Meera P, Toro L (May 1999). "Molecular basis of fast inactivation in voltage and Ca2+-activated K+ channels: a transmembrane beta-subunit homolog". Proc Natl Acad Sci U S A. 96 (7): 4137–42. doi:10.1073/pnas.96.7.4137. PMC 22433. PMID 10097176.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ^ a b "Entrez Gene: KCNMB2 potassium large conductance calcium-activated channel, subfamily M, beta member 2".
- ^ Bentrop D, Beyermann M, Wissmann R, Fakler B (November 2001). "NMR structure of the "ball-and-chain" domain of KCNMB2, the beta 2-subunit of large conductance Ca2+- and voltage-activated potassium channels". J. Biol. Chem. 276 (45): 42116–21. doi:10.1074/jbc.M107118200. PMID 11517232.
{{cite journal}}: CS1 maint: multiple names: authors list (link) CS1 maint: unflagged free DOI (link)
Further reading
External links
- KCNMB2 human gene location in the UCSC Genome Browser.
- KCNMB2 human gene details in the UCSC Genome Browser.
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This article incorporates text from the United States National Library of Medicine, which is in the public domain.
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