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Q9Y691 (KCMB2_HUMAN) Reviewed, UniProtKB/Swiss-Prot

Last modified April 16, 2014. Version 108. Feed History...

Clusters with 100%, 90%, 50% identity | Documents (4) | Third-party data text xml rdf/xml gff fasta
to top of pageNames·Attributes·General annotation·Ontologies·Sequence annotation·Sequences·References·Cross-refs·Entry info·DocumentsCustomize order

Names and origin

Protein namesRecommended name:
Calcium-activated potassium channel subunit beta-2
Alternative name(s):
BK channel subunit beta-2
Short name=BKbeta2
Short name=Hbeta2
Calcium-activated potassium channel, subfamily M subunit beta-2
Charybdotoxin receptor subunit beta-2
Hbeta3
K(VCA)beta-2
Maxi K channel subunit beta-2
Slo-beta-2
Gene names
Name:KCNMB2
OrganismHomo sapiens (Human) [Reference proteome]
Taxonomic identifier9606 [NCBI]
Taxonomic lineageEukaryotaMetazoaChordataCraniataVertebrataEuteleostomiMammaliaEutheriaEuarchontogliresPrimatesHaplorrhiniCatarrhiniHominidaeHomo

Protein attributes

Sequence length235 AA.
Sequence statusComplete.
Protein existenceEvidence at protein level

General annotation (Comments)

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. Acts as a negative regulator that confers rapid and complete inactivation of KCNMA1 channel complex. May participate in KCNMA1 inactivation in chromaffin cells of the adrenal gland or in hippocampal CA1 neurons. Ref.1 Ref.4

Subunit structure

Interacts with KCNMA1 tetramer. There are probably 4 molecules of KCMNB2 per KCNMA1 tetramer. Ref.1

Subcellular location

Membrane; Multi-pass membrane protein.

Tissue specificity

Expressed in kidney, heart and brain. Highly expressed in ovary. Expressed at low level in other tissues. Ref.1 Ref.2 Ref.4

Domain

The ball and chain domain mediates the inactivation of KCNMA1. It occludes the conduction pathway of KCNMA1 channels, and comprises the pore-blocking ball domain (residues 1-17) and the chain domain (residues 20-45) linking it to the transmembrane segment. The ball domain is made up of a flexible N-terminus anchored at a well ordered loop-helix motif. The chain domain consists of a 4-turn helix with an unfolded linker at its C-terminus. Ref.1 Ref.4

Post-translational modification

N-glycosylated. Ref.5

Sequence similarities

Belongs to the KCNMB (TC 8.A.14.1) family. KCNMB2 subfamily. [View classification]

Sequence annotation (Features)

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifier

Molecule processing

Chain1 – 235235Calcium-activated potassium channel subunit beta-2
PRO_0000187051

Regions

Topological domain1 – 4646Cytoplasmic Potential
Transmembrane47 – 6721Helical; Name=1; Potential
Topological domain68 – 194127Extracellular Potential
Transmembrane195 – 21521Helical; Name=2; Potential
Topological domain216 – 23520Cytoplasmic Potential
Region1 – 4545Ball and chain

Amino acid modifications

Glycosylation881N-linked (GlcNAc...) Potential
Glycosylation961N-linked (GlcNAc...) Potential
Glycosylation1191N-linked (GlcNAc...) Potential

Experimental info

Mutagenesis2 – 43FIW → GGG: Abolishes inactivation of KCNMA1 channel. Ref.6

Secondary structure

....... 235
Helix Strand Turn

Details...

Sequences

Sequence LengthMass (Da)Tools
Q9Y691 [UniParc].

Last modified November 1, 1999. Version 1.
Checksum: 5752021DF27D8CF5

FASTA23527,130
        10         20         30         40         50         60 
MFIWTSGRTS SSYRHDEKRN IYQKIRDHDL LDKRKTVTAL KAGEDRAILL GLAMMVCSIM 

        70         80         90        100        110        120 
MYFLLGITLL RSYMQSVWTE ESQCTLLNAS ITETFNCSFS CGPDCWKLSQ YPCLQVYVNL 

       130        140        150        160        170        180 
TSSGEKLLLY HTEETIKINQ KCSYIPKCGK NFEESMSLVN VVMENFRKYQ HFSCYSDPEG 

       190        200        210        220        230 
NQKSVILTKL YSSNVLFHSL FWPTCMMAGG VAIVAMVKLT QYLSLLCERI QRINR 

« Hide

References

« Hide 'large scale' references
[1]"Molecular basis of fast inactivation in voltage and Ca2+-activated K+ channels: a transmembrane beta-subunit homolog."
Wallner M., Meera P., Toro L.
Proc. Natl. Acad. Sci. U.S.A. 96:4137-4142(1999) [PubMed] [Europe PMC] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [MRNA], FUNCTION, DOMAIN, TISSUE SPECIFICITY, INTERACTION WITH KCNMA1.
Tissue: Neuroepithelium.
[2]"Cloning and functional characterization of novel large conductance calcium-activated potassium channel beta subunits, hKCNMB3 and hKCNMB4."
Brenner R., Jegla T.J., Wickenden A., Liu Y., Aldrich R.W.
J. Biol. Chem. 275:6453-6461(2000) [PubMed] [Europe PMC] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [MRNA], TISSUE SPECIFICITY.
Tissue: Ovary.
[3]"The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC)."
The MGC Project Team
Genome Res. 14:2121-2127(2004) [PubMed] [Europe PMC] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA].
Tissue: Embryonic testis.
[4]"Molecular basis for the inactivation of Ca2+- and voltage-dependent BK channels in adrenal chromaffin cells and rat insulinoma tumor cells."
Xia X.-M., Ding J.-P., Lingle C.J.
J. Neurosci. 19:5255-5264(1999) [PubMed] [Europe PMC] [Abstract]
Cited for: FUNCTION, DOMAIN, TISSUE SPECIFICITY.
[5]"A neuronal beta subunit (KCNMB4) makes the large conductance, voltage- and Ca2+-activated K+ channel resistant to charybdotoxin and iberiotoxin."
Meera P., Wallner M., Toro L.
Proc. Natl. Acad. Sci. U.S.A. 97:5562-5567(2000) [PubMed] [Europe PMC] [Abstract]
Cited for: GLYCOSYLATION.
[6]"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."
Xia X.-M., Ding J.-P., Lingle C.J.
J. Gen. Physiol. 121:125-148(2003) [PubMed] [Europe PMC] [Abstract]
Cited for: MUTAGENESIS OF 2-PHE--TRP-4.
[7]"New disguises for an old channel: MaxiK channel beta-subunits."
Orio P., Rojas P., Ferreira G., Latorre R.
News Physiol. Sci. 17:156-161(2002) [PubMed] [Europe PMC] [Abstract]
Cited for: REVIEW.
[8]"NMR structure of the 'ball-and-chain' domain of KCNMB2, the beta 2-subunit of large conductance Ca2+- and voltage-activated potassium channels."
Bentrop D., Beyermann M., Wissmann R., Fakler B.
J. Biol. Chem. 276:42116-42121(2001) [PubMed] [Europe PMC] [Abstract]
Cited for: STRUCTURE BY NMR OF 1-45.
+Additional computationally mapped references.

Cross-references

Sequence databases

EMBL
GenBank
DDBJ
AF099137 mRNA. Translation: AAD23380.1.
AF209747 mRNA. Translation: AAF36562.1.
BC017825 mRNA. Translation: AAH17825.1.
RefSeqNP_001265840.1. NM_001278911.1.
NP_005823.1. NM_005832.4.
NP_852006.1. NM_181361.2.
UniGeneHs.478368.

3D structure databases

PDBe
RCSB PDB
PDBj
EntryMethodResolution (Å)ChainPositionsPDBsum
1JO6NMR-A1-45[»]
ProteinModelPortalQ9Y691.
SMRQ9Y691. Positions 1-45.
ModBaseSearch...
MobiDBSearch...

Protein-protein interaction databases

BioGrid115536. 1 interaction.
IntActQ9Y691. 1 interaction.
MINTMINT-8381989.
STRING9606.ENSP00000351068.

Protein family/group databases

TCDB8.A.14.1.3. the ca(2+)-activated k(+) channel auxiliary subunit slowpoke- (slo) family.

PTM databases

PhosphoSiteQ9Y691.

Polymorphism databases

DMDM46396054.

Proteomic databases

PaxDbQ9Y691.
PRIDEQ9Y691.

Protocols and materials databases

DNASU10242.
StructuralBiologyKnowledgebaseSearch...

Genome annotation databases

EnsemblENST00000358316; ENSP00000351068; ENSG00000197584.
ENST00000420517; ENSP00000408252; ENSG00000197584.
ENST00000432997; ENSP00000407592; ENSG00000197584.
ENST00000452583; ENSP00000397483; ENSG00000197584.
GeneID10242.
KEGGhsa:10242.
UCSCuc003fjd.3. human.

Organism-specific databases

CTD10242.
GeneCardsGC03P177990.
HGNCHGNC:6286. KCNMB2.
HPACAB022649.
MIM605214. gene.
neXtProtNX_Q9Y691.
PharmGKBPA30066.
GenAtlasSearch...

Phylogenomic databases

eggNOGNOG44064.
HOVERGENHBG052223.
InParanoidQ9Y691.
KOK04938.
OMAMKINQKC.
PhylomeDBQ9Y691.
TreeFamTF328589.

Enzyme and pathway databases

ReactomeREACT_13685. Neuronal System.
REACT_604. Hemostasis.

Gene expression databases

ArrayExpressQ9Y691.
BgeeQ9Y691.
CleanExHS_KCNMB2.
GenevestigatorQ9Y691.

Family and domain databases

Gene3D4.10.81.20. 1 hit.
InterProIPR003930. K_chnl_Ca-activ_BK_bsu.
IPR015382. KCNMB2_ball_chain_dom.
[Graphical view]
PANTHERPTHR10258. PTHR10258. 1 hit.
PfamPF03185. CaKB. 1 hit.
PF09303. KcnmB2_inactiv. 1 hit.
[Graphical view]
PRINTSPR01450. BKCHANNELB.
ProtoNetSearch...

Other

EvolutionaryTraceQ9Y691.
GeneWikiKCNMB2.
GenomeRNAi10242.
NextBio38800.
PROQ9Y691.
SOURCESearch...

Entry information

Entry nameKCMB2_HUMAN
AccessionPrimary (citable) accession number: Q9Y691
Entry history
Integrated into UniProtKB/Swiss-Prot: April 13, 2004
Last sequence update: November 1, 1999
Last modified: April 16, 2014
This is version 108 of the entry and version 1 of the sequence. [Complete history]
Entry statusReviewed (UniProtKB/Swiss-Prot)
Annotation programChordata Protein Annotation Program
DisclaimerAny medical or genetic information present in this entry is provided for research, educational and informational purposes only. It is not in any way intended to be used as a substitute for professional medical advice, diagnosis, treatment or care.

Relevant documents

SIMILARITY comments

Index of protein domains and families

PDB cross-references

Index of Protein Data Bank (PDB) cross-references

MIM cross-references

Online Mendelian Inheritance in Man (MIM) cross-references in UniProtKB/Swiss-Prot

Human chromosome 3

Human chromosome 3: entries, gene names and cross-references to MIM