Summary: KCNMB2, ball and chain domain
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KCNMB2 Edit Wikipedia article
| KCNMB2, ball and chain domain | |||||||||
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solution structure of the cytoplasmic n-terminus of the bk beta-subunit kcnmb2 |
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| 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.
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[edit] See also
[edit] 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): 4137â42. doi:10.1073/pnas.96.7.4137. PMC 22433. PMID 10097176.
- ^ 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): 42116â21. doi:10.1074/jbc.M107118200. PMID 11517232.
[edit] Further reading
- Orio P, Rojas P, Ferreira G, Latorre R (2002). "New disguises for an old channel: MaxiK channel beta-subunits". News Physiol. Sci. 17: 156â61. PMID 12136044.
- Xia XM, Ding JP, Lingle CJ (1999). "Molecular basis for the inactivation of Ca2+- and voltage-dependent BK channels in adrenal chromaffin cells and rat insulinoma tumor cells". J. Neurosci. 19 (13): 5255â64. PMID 10377337.
- Brenner R, Jegla TJ, Wickenden A, et al. (2000). "Cloning and functional characterization of novel large conductance calcium-activated potassium channel beta subunits, hKCNMB3 and hKCNMB4". J. Biol. Chem. 275 (9): 6453â61. doi:10.1074/jbc.275.9.6453. PMID 10692449.
- Liu QH, Williams DA, McManus C, et al. (2000). "HIV-1 gp120 and chemokines activate ion channels in primary macrophages through CCR5 and CXCR4 stimulation". Proc. Natl. Acad. Sci. U.S.A. 97 (9): 4832â7. doi:10.1073/pnas.090521697. PMC 18318. PMID 10758170.
- Uebele VN, Lagrutta A, Wade T, et al. (2000). "Cloning and functional expression of two families of beta-subunits of the large conductance calcium-activated K+ channel". J. Biol. Chem. 275 (30): 23211â8. doi:10.1074/jbc.M910187199. PMID 10766764.
- Meera P, Wallner M, Toro L (2000). "A neuronal beta subunit (KCNMB4) makes the large conductance, voltage- and Ca2+-activated K+ channel resistant to charybdotoxin and iberiotoxin". Proc. Natl. Acad. Sci. U.S.A. 97 (10): 5562â7. doi:10.1073/pnas.100118597. PMC 25868. PMID 10792058.
- Bentrop D, Beyermann M, Wissmann R, Fakler B (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): 42116â21. doi:10.1074/jbc.M107118200. PMID 11517232.
- Strausberg RL, Feingold EA, Grouse LH, et al. (2003). "Generation and initial analysis of more than 15,000 full-length human and mouse cDNA sequences". Proc. Natl. Acad. Sci. U.S.A. 99 (26): 16899â903. doi:10.1073/pnas.242603899. PMC 139241. PMID 12477932.
- Xia XM, Ding JP, Lingle CJ (2003). "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". J. Gen. Physiol. 121 (2): 125â48. doi:10.1085/jgp.20028667. PMC 2217327. PMID 12566540.
- Hartness ME, Brazier SP, Peers C, et al. (2004). "Post-transcriptional control of human maxiK potassium channel activity and acute oxygen sensitivity by chronic hypoxia". J. Biol. Chem. 278 (51): 51422â32. doi:10.1074/jbc.M309463200. PMID 14522958.
- Gerhard DS, Wagner L, Feingold EA, et al. (2004). "The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC)". Genome Res. 14 (10B): 2121â7. doi:10.1101/gr.2596504. PMC 528928. PMID 15489334.
- Orio P, Torres Y, Rojas P, et al. (2006). "Structural determinants for functional coupling between the beta and alpha subunits in the Ca2+-activated K+ (BK) channel". J. Gen. Physiol. 127 (2): 191â204. doi:10.1085/jgp.200509370. PMC 2151488. PMID 16446507.
- Zeng XH, Benzinger GR, Xia XM, Lingle CJ (2007). "BK channels with beta3a subunits generate use-dependent slow afterhyperpolarizing currents by an inactivation-coupled mechanism". J. Neurosci. 27 (17): 4707â15. doi:10.1523/JNEUROSCI.0758-07.2007. PMID 17460083.
- Zarei MM, Song M, Wilson RJ, et al. (2007). "Endocytic trafficking signals in KCNMB2 regulate surface expression of a large conductance voltage and Ca(2+)-activated K+ channel". Neuroscience 147 (1): 80â9. doi:10.1016/j.neuroscience.2007.04.019. PMID 17521822.
[edit] 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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This article incorporates text from the public domain Pfam and InterPro IPR015382
This page is based on a Wikipedia article. The text is available under the Creative Commons Attribution/Share-Alike License.
This tab holds the annotation information that is stored in the Pfam database. As we move to using Wikipedia as our main source of annotation, the contents of this tab will be gradually replaced by the Wikipedia tab.
KCNMB2, ball and chain domain Provide feedback
Members of this family are found in the cytoplasmic N-terminus of KCNMB2, the beta-2 subunit of large conductance calcium and voltage-activated potassium channels. They are responsible for the fast inactivation of these channels [1].
Literature references
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Bentrop D, Beyermann M, Wissmann R, Fakler B; , J Biol Chem. 2001;276:42116-42121.: NMR structure of the "ball-and-chain" domain of KCNMB2, the beta 2-subunit of large conductance Ca2+- and voltage-activated potassium channels. PUBMED:11517232 EPMC:11517232
External database links
| PANDIT: | PF09303 |
| Pseudofam: | PF09303 |
| SYSTERS: | KcnmB2_inactiv |
This tab holds annotation information from the InterPro database.
InterPro entry IPR015382
This domain is found in the cytoplasmic N terminus of KCNMB2, the beta-2 subunit of large conductance calcium and voltage-activated potassium channels. It is responsible for the fast inactivation of these channels [PUBMED:11517232].
11517232Domain organisation
Below is a listing of the unique domain organisations or architectures in which this domain is found. More...
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Alignments
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| Seed (7) |
Full (63) |
Representative proteomes | NCBI (55) |
Meta (0) |
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| RP15 (1) |
RP35 (3) |
RP55 (9) |
RP75 (25) |
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| PP/heatmap | 1 | |||||||
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We make all of our alignments available in Stockholm format. You can download them here as raw, plain text files or as gzip-compressed files.
| Seed (7) |
Full (63) |
Representative proteomes | NCBI (55) |
Meta (0) |
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| RP15 (1) |
RP35 (3) |
RP55 (9) |
RP75 (25) |
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| Raw Stockholm | ||||||||
| Gzipped | ||||||||
You can also download a FASTA format file containing the full-length sequences for all sequences in the full alignment.
External links
MyHits provides a collection of tools to handle multiple sequence alignments. For example, one can refine a seed alignment (sequence addition or removal, re-alignment or manual edition) and then search databases for remote homologs using HMMER3.
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HMM logos is one way of visualising profile HMMs. Logos provide a quick overview of the properties of an HMM in a graphical form. You can see a more detailed description of HMM logos and find out how you can interpret them here. More...
Trees
This page displays the phylogenetic tree for this family's seed alignment. We use FastTree to calculate neighbour join trees with a local bootstrap based on 100 resamples (shown next to the tree nodes). FastTree calculates approximately-maximum-likelihood phylogenetic trees from our seed alignment.
Note: You can also download the data file for the tree.
Curation and family details
This section shows the detailed information about the Pfam family. You can see the definitions of many of the terms in this section in the glossary and a fuller explanation of the scoring system that we use in the scores section of the help pages.
Curation
| Seed source: | pdb_1jo6 |
| Previous IDs: | none |
| Type: | Domain |
| Author: | Mistry J, Sammut SJ |
| Number in seed: | 7 |
| Number in full: | 63 |
| Average length of the domain: | 29.60 aa |
| Average identity of full alignment: | 80 % |
| Average coverage of the sequence by the domain: | 15.20 % |
HMM information
| HMM build commands: |
build method: hmmbuild -o /dev/null HMM SEED
search method: hmmsearch -Z 23193494 -E 1000 --cpu 4 HMM pfamseq
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| Model details: |
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| Model length: | 32 | ||||||||||||
| Family (HMM) version: | 5 | ||||||||||||
| Download: | download the raw HMM for this family |
Species distribution
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Structures
For those sequences which have a structure in the Protein DataBank, we use the mapping between UniProt, PDB and Pfam coordinate systems from the PDBe group, to allow us to map Pfam domains onto UniProt sequences and three-dimensional protein structures. The table below shows the structures on which the KcnmB2_inactiv domain has been found. There are 1 instances of this domain found in the PDB. Note that there may be multiple copies of the domain in a single PDB structure, since many structures contain multiple copies of the same protein seqence.
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Eukaryota
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Unclassified sequence