KCNMB2

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Potassium large conductance calcium-activated channel, subfamily M, beta member 2
Protein KCNMB2 PDB 1jo6.png
PDB rendering based on 1jo6.
Available structures
PDB Ortholog search: PDBe, RCSB
Identifiers
Symbols KCNMB2 ; MGC22431
External IDs OMIM605214 MGI1919663 HomoloGene4257 GeneCards: KCNMB2 Gene
RNA expression pattern
PBB GE KCNMB2 221097 s at tn.png
More reference expression data
Orthologs
Species Human Mouse
Entrez 10242 72413
Ensembl ENSG00000197584 ENSMUSG00000037610
UniProt Q9Y691 Q9CZM9
RefSeq (mRNA) NM_005832 NM_028231
RefSeq (protein) NP_005823 NP_082507
Location (UCSC) Chr 3:
177.99 – 178.56 Mb
Chr 3:
31.9 – 32.2 Mb
PubMed search [1] [2]
KCNMB2, ball and chain domain
PDB 1jo6 EBI.jpg
solution structure of the cytoplasmic n-terminus of the bk beta-subunit kcnmb2
Identifiers
Symbol KcnmB2_inactiv
Pfam PF09303
InterPro IPR015382

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.

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References[edit]

  1. ^ 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. 
  2. ^ a b "Entrez Gene: KCNMB2 potassium large conductance calcium-activated channel, subfamily M, beta member 2". 
  3. ^ 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. 

Further reading[edit]

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

This article incorporates text from the public domain Pfam and InterPro IPR015382