KCNMB2
{{Short description|Protein-coding gene in the species Homo sapiens}}
{{Infobox_gene}}
{{Infobox protein family
| Symbol = KcnmB2_inactiv
| Name = KCNMB2, ball and chain domain
| image = PDB 1jo6 EBI.jpg
| width =
| caption = solution structure of the cytoplasmic n-terminus of the bk beta-subunit kcnmb2
| Pfam = PF09303
| Pfam_clan =
| InterPro = IPR015382
| SMART =
| PROSITE =
| MEROPS =
| SCOP =
| TCDB =
| OPM family =
| OPM protein =
| CAZy =
| CDD =
}}
Calcium-activated potassium channel subunit beta-2 is a protein that in humans is encoded by the KCNMB2 gene.{{cite journal |vauthors=Wallner M, Meera P, Toro L | title = Molecular basis of fast inactivation in voltage and Ca2+-activated K+ channels: a transmembrane beta-subunit homolog | journal = Proc Natl Acad Sci U S A | volume = 96 | issue = 7 | pages = 4137–42 |date=May 1999 | pmid = 10097176 | pmc = 22433 | doi =10.1073/pnas.96.7.4137 | bibcode = 1999PNAS...96.4137W | doi-access = free }}{{cite web | title = Entrez Gene: KCNMB2 potassium large conductance calcium-activated channel, subfamily M, beta member 2| url = https://www.ncbi.nlm.nih.gov/sites/entrez?Db=gene&Cmd=ShowDetailView&TermToSearch=10242}}
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).
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,{{cite journal |vauthors=Bentrop D, Beyermann M, Wissmann R, Fakler B | title = NMR structure of the "ball-and-chain" domain of KCNMB2, the beta 2-subunit of large conductance Ca2+- and voltage-activated potassium channels | journal = J. Biol. Chem. | volume = 276 | issue = 45 | pages = 42116–21 |date=November 2001 | pmid = 11517232 | doi = 10.1074/jbc.M107118200 | doi-access = free }} 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
{{reflist}}
Further reading
{{refbegin | 2}}
- {{cite journal |vauthors=Orio P, Rojas P, Ferreira G, Latorre R |title=New disguises for an old channel: MaxiK channel beta-subunits |journal=News Physiol. Sci. |volume=17 |issue= 4|pages= 156–61 |year= 2002 |pmid= 12136044 |doi= 10.1152/nips.01387.2002|hdl=10533/173696 |hdl-access=free }}
- {{cite journal |vauthors=Xia XM, Ding JP, Lingle CJ |title=Molecular basis for the inactivation of Ca2+- and voltage-dependent BK channels in adrenal chromaffin cells and rat insulinoma tumor cells |journal=J. Neurosci. |volume=19 |issue= 13 |pages= 5255–64 |year= 1999 |pmid= 10377337 |doi= 10.1523/JNEUROSCI.19-13-05255.1999|pmc= 6782330 }}
- {{cite journal |vauthors=Brenner R, Jegla TJ, Wickenden A, etal |title=Cloning and functional characterization of novel large conductance calcium-activated potassium channel beta subunits, hKCNMB3 and hKCNMB4 |journal=J. Biol. Chem. |volume=275 |issue= 9 |pages= 6453–61 |year= 2000 |pmid= 10692449 |doi=10.1074/jbc.275.9.6453 |doi-access=free }}
- {{cite journal |vauthors=Liu QH, Williams DA, McManus C, etal |title=HIV-1 gp120 and chemokines activate ion channels in primary macrophages through CCR5 and CXCR4 stimulation |journal=Proc. Natl. Acad. Sci. U.S.A. |volume=97 |issue= 9 |pages= 4832–7 |year= 2000 |pmid= 10758170 |doi= 10.1073/pnas.090521697 | pmc=18318 |bibcode=2000PNAS...97.4832L |doi-access=free }}
- {{cite journal |vauthors=Uebele VN, Lagrutta A, Wade T, etal |title=Cloning and functional expression of two families of beta-subunits of the large conductance calcium-activated K+ channel |journal=J. Biol. Chem. |volume=275 |issue= 30 |pages= 23211–8 |year= 2000 |pmid= 10766764 |doi= 10.1074/jbc.M910187199 |doi-access= free }}
- {{cite journal |vauthors=Meera P, Wallner M, Toro L |title=A neuronal beta subunit (KCNMB4) makes the large conductance, voltage- and Ca2+-activated K+ channel resistant to charybdotoxin and iberiotoxin |journal=Proc. Natl. Acad. Sci. U.S.A. |volume=97 |issue= 10 |pages= 5562–7 |year= 2000 |pmid= 10792058 |doi= 10.1073/pnas.100118597 | pmc=25868 |bibcode=2000PNAS...97.5562M |doi-access=free }}
- {{cite journal |vauthors=Bentrop D, Beyermann M, Wissmann R, Fakler B |title=NMR structure of the "ball-and-chain" domain of KCNMB2, the beta 2-subunit of large conductance Ca2+- and voltage-activated potassium channels |journal=J. Biol. Chem. |volume=276 |issue= 45 |pages= 42116–21 |year= 2001 |pmid= 11517232 |doi= 10.1074/jbc.M107118200 |doi-access= free }}
- {{cite journal |vauthors=Strausberg RL, Feingold EA, Grouse LH, etal |title=Generation and initial analysis of more than 15,000 full-length human and mouse cDNA sequences |journal=Proc. Natl. Acad. Sci. U.S.A. |volume=99 |issue= 26 |pages= 16899–903 |year= 2003 |pmid= 12477932 |doi= 10.1073/pnas.242603899 | pmc=139241 |bibcode=2002PNAS...9916899M |doi-access=free }}
- {{cite journal |vauthors=Xia XM, Ding JP, Lingle CJ |title=Inactivation of BK channels by the NH2 terminus of the beta2 auxiliary subunit: an essential role of a terminal peptide segment of three hydrophobic residues |journal=J. Gen. Physiol. |volume=121 |issue= 2 |pages= 125–48 |year= 2003 |pmid= 12566540 |doi=10.1085/jgp.20028667 | pmc=2217327 }}
- {{cite journal |vauthors=Hartness ME, Brazier SP, Peers C, etal |title=Post-transcriptional control of human maxiK potassium channel activity and acute oxygen sensitivity by chronic hypoxia |journal=J. Biol. Chem. |volume=278 |issue= 51 |pages= 51422–32 |year= 2004 |pmid= 14522958 |doi= 10.1074/jbc.M309463200 |doi-access= free }}
- {{cite journal |vauthors=Gerhard DS, Wagner L, Feingold EA, etal |title=The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC) |journal=Genome Res. |volume=14 |issue= 10B |pages= 2121–7 |year= 2004 |pmid= 15489334 |doi= 10.1101/gr.2596504 | pmc=528928 }}
- {{cite journal |vauthors=Orio P, Torres Y, Rojas P, etal |title=Structural determinants for functional coupling between the beta and alpha subunits in the Ca2+-activated K+ (BK) channel |journal=J. Gen. Physiol. |volume=127 |issue= 2 |pages= 191–204 |year= 2006 |pmid= 16446507 |doi= 10.1085/jgp.200509370 | pmc=2151488 }}
- {{cite journal |vauthors=Zeng XH, Benzinger GR, Xia XM, Lingle CJ |title=BK channels with beta3a subunits generate use-dependent slow afterhyperpolarizing currents by an inactivation-coupled mechanism |journal=J. Neurosci. |volume=27 |issue= 17 |pages= 4707–15 |year= 2007 |pmid= 17460083 |doi= 10.1523/JNEUROSCI.0758-07.2007 |pmc=6672991 |doi-access= free }}
- {{cite journal |vauthors=Zarei MM, Song M, Wilson RJ, etal |title=Endocytic trafficking signals in KCNMB2 regulate surface expression of a large conductance voltage and Ca(2+)-activated K+ channel |journal=Neuroscience |volume=147 |issue= 1 |pages= 80–9 |year= 2007 |pmid= 17521822 |doi= 10.1016/j.neuroscience.2007.04.019 |s2cid=24449192 }}
{{refend}}
External links
- {{UCSC genome browser|KCNMB2}}
- {{UCSC gene details|KCNMB2}}
{{NLM content}}
{{PDB Gallery|geneid=10242}}
{{Ion channels|g3}}
{{InterPro content|IPR015382}}
{{membrane-protein-stub}}