KCNMB2

KCNMB2
Available structures
PDBOrtholog search: PDBe RCSB
Identifiers
AliasesKCNMB2, potassium calcium-activated channel subfamily M regulatory beta subunit 2
External IDsOMIM: 605214; MGI: 1919663; HomoloGene: 4257; GeneCards: KCNMB2; OMA:KCNMB2 - orthologs
Orthologs
SpeciesHumanMouse
Entrez
Ensembl
UniProt
RefSeq (mRNA)

NM_001278911
NM_005832
NM_181361

NM_028231

RefSeq (protein)

NP_001265840
NP_005823
NP_852006

NP_082507

Location (UCSC)Chr 3: 178.27 – 178.84 MbChr 3: 31.96 – 32.25 Mb
PubMed search[3][4]
Wikidata
View/Edit HumanView/Edit Mouse
KCNMB2, ball and chain domain
solution structure of the cytoplasmic n-terminus of the bk beta-subunit kcnmb2
Identifiers
SymbolKcnmB2_inactiv
PfamPF09303
InterProIPR015382
Available protein structures:
Pfam  structures / ECOD  
PDBRCSB PDB; PDBe; PDBj
PDBsumstructure summary

Calcium-activated potassium channel subunit beta-2 is a protein that in humans is encoded by the KCNMB2 gene.[5][6]

Big Potassium (BK) channels are large conductance, voltage and calcium-sensitive potassium channels which are fundamental to the control of smooth muscle tone and neuronal excitability. BK channels can contain two distinct subunits: a pore-forming alpha subunit and a modulatory beta subunit. Each complete BK 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 BK currents and, following activation of BK 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 BK auxiliary subunit).[6]

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,[7] 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.

  1. ^ a b c GRCh38: Ensembl release 89: ENSG00000197584Ensembl, May 2017
  2. ^ a b c GRCm38: Ensembl release 89: ENSMUSG00000037610Ensembl, May 2017
  3. ^ "Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  4. ^ "Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  5. ^ 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. Bibcode:1999PNAS...96.4137W. doi:10.1073/pnas.96.7.4137. PMC 22433. PMID 10097176.
  6. ^ a b "Entrez Gene: KCNMB2 potassium large conductance calcium-activated channel, subfamily M, beta member 2".
  7. ^ 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.