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Identification
HMDB Protein ID HMDBP07755
Secondary Accession Numbers
  • 13464
Name Calcium-activated potassium channel subunit beta-3
Synonyms
  1. BK channel subunit beta-3
  2. BKbeta3
  3. Calcium-activated potassium channel, subfamily M subunit beta-3
  4. Charybdotoxin receptor subunit beta-3
  5. Hbeta3
  6. K(VCA)beta-3
  7. Maxi K channel subunit beta-3
  8. Slo-beta-3
Gene Name KCNMB3
Protein Type Unknown
Biological Properties
General Function Involved in calcium-activated potassium channel activity
Specific Function Regulatory subunit of the calcium activated potassium KCNMA1 (maxiK) channel. Modulates the calcium sensitivity and gating kinetics of KCNMA1, thereby contributing to KCNMA1 channel diversity. Alters the functional properties of the current expressed by the KCNMA1 channel. Isoform 2, isoform 3 and isoform 4 partially inactivate the current of KCNBMA. Isoform 4 induces a fast and incomplete inactivation of KCNMA1 channel that is detectable only at large depolarizations. In contrast, isoform 1 does not induce detectable inactivation of KCNMA1. Two or more subunits of KCNMB3 are required to block the KCNMA1 tetramer
Pathways Not Available
Reactions Not Available
GO Classification
Component
membrane
cell part
Function
calcium activated cation channel activity
calcium-activated potassium channel activity
transmembrane transporter activity
substrate-specific transmembrane transporter activity
ion transmembrane transporter activity
transporter activity
ion channel activity
cation channel activity
Process
establishment of localization
transport
monovalent inorganic cation transport
potassium ion transport
ion transport
cation transport
Cellular Location
  1. Membrane
  2. Multi-pass membrane protein
Gene Properties
Chromosome Location Chromosome:3
Locus 3q26.3-q27
SNPs KCNMB3
Gene Sequence
>840 bp
ATGGACTTTTCACCAAGCTCTGAACTGGGATTTCATTTTGTTGCATTCATCCTGCTCACG
AGACACAGGACAGCCTTTCCTGCCTCAGGGAAGAAGAGAGAGACAGACTACAGTGATGGA
GACCCACTAGATGTGCACAAGAGGCTGCCATCCAGTGCTGGAGAGGACCGAGCCGTGATG
CTGGGGTTTGCCATGATGGGCTTCTCAGTCCTAATGTTCTTCTTGCTCGGAACAACCATT
CTAAAGCCTTTTATGCTCAGCATTCAGAGAGAAGAATCGACCTGCACTGCCATCCACACA
GATATCATGGACGACTGGCTGGACTGTGCCTTCACCTGTGGTGTGCACTGCCACGGTCAG
GGGAAGTACCCGTGTCTTCAGGTGTTTGTGAACCTCAGCCATCCAGGTCAGAAAGCTCTC
CTACATTATAATGAAGAGGCTGTCCAGATAAATCCCAAGTGCTTTTACACACCTAAGTGC
CACCAAGATAGAAATGATTTGCTCAACAGTGCTCTGGACATAAAAGAATTCTTCGATCAC
AAAAATGGAACCCCCTTTTCATGCTTCTACAGTCCAGCCAGCCAATCTGAAGATGTCATT
CTTATAAAAAAGTATGACCAAATGGCTATCTTCCACTGTTTATTTTGGCCTTCACTGACT
CTGCTAGGTGGTGCCCTGATTGTTGGCATGGTGAGATTAACACAACACCTGTCCTTACTG
TGTGAAAAATATAGCACTGTAGTCAGAGATGAGGTAGGTGGAAAAGTACCTTATATAGAA
CAGCATCAGTTCAAACTGTGCATTATGAGGAGGAGCAAAGGAAGAGCAGAGAAATCTTAA
Protein Properties
Number of Residues 279
Molecular Weight 31603.3
Theoretical pI 7.31
Pfam Domain Function
Signals
  • None
Transmembrane Regions
  • 61-81
  • 208-228
Protein Sequence
>Calcium-activated potassium channel subunit beta-3
MDFSPSSELGFHFVAFILLTRHRTAFPASGKKRETDYSDGDPLDVHKRLPSSAGEDRAVM
LGFAMMGFSVLMFFLLGTTILKPFMLSIQREESTCTAIHTDIMDDWLDCAFTCGVHCHGQ
GKYPCLQVFVNLSHPGQKALLHYNEEAVQINPKCFYTPKCHQDRNDLLNSALDIKEFFDH
KNGTPFSCFYSPASQSEDVILIKKYDQMAIFHCLFWPSLTLLGGALIVGMVRLTQHLSLL
CEKYSTVVRDEVGGKVPYIEQHQFKLCIMRRSKGRAEKS
GenBank ID Protein 25952095
UniProtKB/Swiss-Prot ID Q9NPA1
UniProtKB/Swiss-Prot Entry Name KCMB3_HUMAN
PDB IDs Not Available
GenBank Gene ID NM_014407.3
GeneCard ID KCNMB3
GenAtlas ID KCNMB3
HGNC ID HGNC:6287
References
General References
  1. Brenner R, Jegla TJ, Wickenden A, Liu Y, Aldrich RW: Cloning and functional characterization of novel large conductance calcium-activated potassium channel beta subunits, hKCNMB3 and hKCNMB4. J Biol Chem. 2000 Mar 3;275(9):6453-61. [PubMed:10692449 ]
  2. Meera P, Wallner M, Toro L: 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. 2000 May 9;97(10):5562-7. [PubMed:10792058 ]
  3. Orio P, Rojas P, Ferreira G, Latorre R: New disguises for an old channel: MaxiK channel beta-subunits. News Physiol Sci. 2002 Aug;17:156-61. [PubMed:12136044 ]
  4. Riazi MA, Brinkman-Mills P, Johnson A, Naylor SL, Minoshima S, Shimizu N, Baldini A, McDermid HE: Identification of a putative regulatory subunit of a calcium-activated potassium channel in the dup(3q) syndrome region and a related sequence on 22q11.2. Genomics. 1999 Nov 15;62(1):90-4. [PubMed:10585773 ]
  5. Uebele VN, Lagrutta A, Wade T, Figueroa DJ, Liu Y, McKenna E, Austin CP, Bennett PB, Swanson R: Cloning and functional expression of two families of beta-subunits of the large conductance calcium-activated K+ channel. J Biol Chem. 2000 Jul 28;275(30):23211-8. [PubMed:10766764 ]
  6. Behrens R, Nolting A, Reimann F, Schwarz M, Waldschutz R, Pongs O: hKCNMB3 and hKCNMB4, cloning and characterization of two members of the large-conductance calcium-activated potassium channel beta subunit family. FEBS Lett. 2000 May 26;474(1):99-106. [PubMed:10828459 ]
  7. Xia XM, Ding JP, Zeng XH, Duan KL, Lingle CJ: Rectification and rapid activation at low Ca2+ of Ca2+-activated, voltage-dependent BK currents: consequences of rapid inactivation by a novel beta subunit. J Neurosci. 2000 Jul 1;20(13):4890-903. [PubMed:10864947 ]
  8. Lingle CJ, Zeng XH, Ding JP, Xia XM: Inactivation of BK channels mediated by the NH(2) terminus of the beta3b auxiliary subunit involves a two-step mechanism: possible separation of binding and blockade. J Gen Physiol. 2001 Jun;117(6):583-606. [PubMed:11382808 ]
  9. Zeng XH, Ding JP, Xia XM, Lingle CJ: Gating properties conferred on BK channels by the beta3b auxiliary subunit in the absence of its NH(2)- and COOH termini. J Gen Physiol. 2001 Jun;117(6):607-28. [PubMed:11382809 ]
  10. Hu S, Labuda MZ, Pandolfo M, Goss GG, McDermid HE, Ali DW: Variants of the KCNMB3 regulatory subunit of maxi BK channels affect channel inactivation. Physiol Genomics. 2003 Nov 11;15(3):191-8. [PubMed:14612589 ]
  11. Zeng XH, Xia XM, Lingle CJ: Redox-sensitive extracellular gates formed by auxiliary beta subunits of calcium-activated potassium channels. Nat Struct Biol. 2003 Jun;10(6):448-54. [PubMed:12740608 ]