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Q16558 (KCMB1_HUMAN) Reviewed, UniProtKB/Swiss-Prot

Last modified April 16, 2014. Version 117. Feed History...

Clusters with 100%, 90%, 50% identity | Documents (5) | Third-party data text xml rdf/xml gff fasta
to top of pageNames·Attributes·General annotation·Ontologies·Alt products·Sequence annotation·Sequences·References·Cross-refs·Entry info·DocumentsCustomize order

Names and origin

Protein namesRecommended name:
Calcium-activated potassium channel subunit beta-1
Alternative name(s):
BK channel subunit beta-1
Short name=BKbeta
Short name=BKbeta1
Short name=Hbeta1
Calcium-activated potassium channel, subfamily M subunit beta-1
Short name=Calcium-activated potassium channel subunit beta
Charybdotoxin receptor subunit beta-1
K(VCA)beta-1
Maxi K channel subunit beta-1
Slo-beta-1
Short name=Slo-beta
Gene names
Name:KCNMB1
OrganismHomo sapiens (Human) [Reference proteome]
Taxonomic identifier9606 [NCBI]
Taxonomic lineageEukaryotaMetazoaChordataCraniataVertebrataEuteleostomiMammaliaEutheriaEuarchontogliresPrimatesHaplorrhiniCatarrhiniHominidaeHomo

Protein attributes

Sequence length191 AA.
Sequence statusComplete.
Sequence processingThe displayed sequence is further processed into a mature form.
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. Increases the apparent Ca2+/voltage sensitivity of the KCNMA1 channel. It also modifies KCNMA1 channel kinetics and alters its pharmacological properties. It slows down the activation and the deactivation kinetics of the channel. Acts as a negative regulator of smooth muscle contraction by enhancing the calcium sensitivity to KCNMA1. Its presence is also a requirement for internal binding of the KCNMA1 channel opener dehydrosoyasaponin I (DHS-1) triterpene glycoside and for external binding of the agonist hormone 17-beta-estradiol (E2). Increases the binding activity of charybdotoxin (CTX) toxin to KCNMA1 peptide blocker by increasing the CTX association rate and decreasing the dissociation rate.

Subunit structure

Interacts with KCNMA1 tetramer. There are probably 4 molecules of KCMNB1 per KCNMA1 tetramer.

Subcellular location

Membrane; Multi-pass membrane protein.

Tissue specificity

Abundantly expressed in smooth muscle. Low levels of expression in most other tissues. Within the brain, relatively high levels found in hippocampus and corpus callosum.

Post-translational modification

N-glycosylated. Ref.11

Polymorphism

Genetic variation in KCNMB1 can influence the severity of diastolic hypertension.

Sequence similarities

Belongs to the KCNMB (TC 8.A.14.1) family. KCNMB1 subfamily. [View classification]

Alternative products

This entry describes 2 isoforms produced by alternative splicing. [Align] [Select]
Isoform 1 (identifier: Q16558-1)

This isoform has been chosen as the 'canonical' sequence. All positional information in this entry refers to it. This is also the sequence that appears in the downloadable versions of the entry.
Isoform 2 (identifier: Q16558-2)

The sequence of this isoform differs from the canonical sequence as follows:
     103-130: CSYIPGSVDNYQTARADVEKVRAKFQEQ → VLNWRDGDTSLYPCQVCEPVPNCPCPRG
     131-191: Missing.
Note: No experimental confirmation available.

Sequence annotation (Features)

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifier

Molecule processing

Initiator methionine11Removed By similarity
Chain2 – 191190Calcium-activated potassium channel subunit beta-1
PRO_0000187046

Regions

Topological domain2 – 1817Cytoplasmic Potential
Transmembrane19 – 3921Helical; Name=1; Potential
Topological domain40 – 157118Extracellular Potential
Transmembrane158 – 17821Helical; Name=2; Potential
Topological domain179 – 19113Cytoplasmic Potential

Amino acid modifications

Glycosylation801N-linked (GlcNAc...) Potential
Glycosylation1421N-linked (GlcNAc...) Potential

Natural variations

Alternative sequence103 – 13028CSYIP…KFQEQ → VLNWRDGDTSLYPCQVCEPV PNCPCPRG in isoform 2.
VSP_009822
Alternative sequence131 – 19161Missing in isoform 2.
VSP_009823
Natural variant651E → K Has a protective effect against diastolic hypertension. Ref.14
Corresponds to variant rs11739136 [ dbSNP | Ensembl ].
VAR_019325
Natural variant1101V → L.
Corresponds to variant rs2301149 [ dbSNP | Ensembl ].
VAR_047009

Sequences

Sequence LengthMass (Da)Tools
Isoform 1 [UniParc].

Last modified March 23, 2010. Version 5.
Checksum: 547432FF194E770D

FASTA19121,797
        10         20         30         40         50         60 
MVKKLVMAQK RGETRALCLG VTMVVCAVIT YYILVTTVLP LYQKSVWTQE SKCHLIETNI 

        70         80         90        100        110        120 
RDQEELKGKK VPQYPCLWVN VSAAGRWAVL YHTEDTRDQN QQCSYIPGSV DNYQTARADV 

       130        140        150        160        170        180 
EKVRAKFQEQ QVFYCFSAPR GNETSVLFQR LYGPQALLFS LFWPTFLLTG GLLIIAMVKS 

       190 
NQYLSILAAQ K 

« Hide

Isoform 2 [UniParc].

Checksum: 2E612865F4130EEE
Show »

FASTA13014,858

References

« Hide 'large scale' references
[1]"A calcium switch for the functional coupling between alpha (hslo) and beta subunits (KV,Ca beta) of maxi K channels."
Meera P., Wallner M., Jiang Z., Toro L.
FEBS Lett. 382:84-88(1996) [PubMed] [Europe PMC] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [MRNA] (ISOFORM 1).
Tissue: Uterus.
[2]"Phenotypic alteration of a human BK (hSlo) channel by hSlobeta subunit coexpression: changes in blocker sensitivity, activation/relaxation and inactivation kinetics, and protein kinase A modulation."
Dworetzky S.I., Boissard C.G., Lum-Ragan J.T., McKay M.C., Post-Munson D.J., Trojnacki J.T., Chang C.P., Gribkoff V.K.
J. Neurosci. 16:4543-4550(1996) [PubMed] [Europe PMC] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [MRNA] (ISOFORM 1).
Tissue: Uterus.
[3]"Cloning, expression, and distribution of a Ca(2+)-activated K+ channel beta-subunit from human brain."
Tseng-Crank J., Godinot N., Johansen T.E., Ahring P.K., Strobaek D., Mertz R., Foster C.D., Olesen S.P., Reinhart P.H.
Proc. Natl. Acad. Sci. U.S.A. 93:9200-9205(1996) [PubMed] [Europe PMC] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA / MRNA] (ISOFORM 1).
Tissue: Brain.
[4]"Sequence of the gene encoding the beta subunit of a human, large-conductance, calcium-activate, K+ channel."
Folander K., Biazzo D., Swanson R.
Submitted (JUN-1997) to the EMBL/GenBank/DDBJ databases
Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA / MRNA] (ISOFORM 1).
Tissue: Aortic smooth muscle.
[5]"Identification of potassium channels in human lens epithelium."
Rae J.L., Shepard A.R.
(In) Civan M.M. (eds.); The eye's aqueous humor, from secretion to glaucoma, pp.69-104, Academic Press, San Diego (1998)
Cited for: NUCLEOTIDE SEQUENCE [MRNA] (ISOFORM 1).
[6]"Calcium-activated potassium channel expression in human myometrium: effect of pregnancy."
Mazzone J.N., Kaiser R.A., Buxton I.L.O.
Proc. West. Pharmacol. Soc. 45:184-186(2002) [PubMed] [Europe PMC] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [MRNA] (ISOFORM 1).
Tissue: Myometrium.
[7]"Role of the BK-beta1 subunit in human mesangial cells."
Pluznick J.L., Sansom S.C.
Submitted (DEC-2003) to the EMBL/GenBank/DDBJ databases
Cited for: NUCLEOTIDE SEQUENCE [MRNA] (ISOFORM 1).
[8]"Complete sequencing and characterization of 21,243 full-length human cDNAs."
Ota T., Suzuki Y., Nishikawa T., Otsuki T., Sugiyama T., Irie R., Wakamatsu A., Hayashi K., Sato H., Nagai K., Kimura K., Makita H., Sekine M., Obayashi M., Nishi T., Shibahara T., Tanaka T., Ishii S. expand/collapse author list , Yamamoto J., Saito K., Kawai Y., Isono Y., Nakamura Y., Nagahari K., Murakami K., Yasuda T., Iwayanagi T., Wagatsuma M., Shiratori A., Sudo H., Hosoiri T., Kaku Y., Kodaira H., Kondo H., Sugawara M., Takahashi M., Kanda K., Yokoi T., Furuya T., Kikkawa E., Omura Y., Abe K., Kamihara K., Katsuta N., Sato K., Tanikawa M., Yamazaki M., Ninomiya K., Ishibashi T., Yamashita H., Murakawa K., Fujimori K., Tanai H., Kimata M., Watanabe M., Hiraoka S., Chiba Y., Ishida S., Ono Y., Takiguchi S., Watanabe S., Yosida M., Hotuta T., Kusano J., Kanehori K., Takahashi-Fujii A., Hara H., Tanase T.-O., Nomura Y., Togiya S., Komai F., Hara R., Takeuchi K., Arita M., Imose N., Musashino K., Yuuki H., Oshima A., Sasaki N., Aotsuka S., Yoshikawa Y., Matsunawa H., Ichihara T., Shiohata N., Sano S., Moriya S., Momiyama H., Satoh N., Takami S., Terashima Y., Suzuki O., Nakagawa S., Senoh A., Mizoguchi H., Goto Y., Shimizu F., Wakebe H., Hishigaki H., Watanabe T., Sugiyama A., Takemoto M., Kawakami B., Yamazaki M., Watanabe K., Kumagai A., Itakura S., Fukuzumi Y., Fujimori Y., Komiyama M., Tashiro H., Tanigami A., Fujiwara T., Ono T., Yamada K., Fujii Y., Ozaki K., Hirao M., Ohmori Y., Kawabata A., Hikiji T., Kobatake N., Inagaki H., Ikema Y., Okamoto S., Okitani R., Kawakami T., Noguchi S., Itoh T., Shigeta K., Senba T., Matsumura K., Nakajima Y., Mizuno T., Morinaga M., Sasaki M., Togashi T., Oyama M., Hata H., Watanabe M., Komatsu T., Mizushima-Sugano J., Satoh T., Shirai Y., Takahashi Y., Nakagawa K., Okumura K., Nagase T., Nomura N., Kikuchi H., Masuho Y., Yamashita R., Nakai K., Yada T., Nakamura Y., Ohara O., Isogai T., Sugano S.
Nat. Genet. 36:40-45(2004) [PubMed] [Europe PMC] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA] (ISOFORM 1).
Tissue: Cervix.
[9]Mural R.J., Istrail S., Sutton G.G., Florea L., Halpern A.L., Mobarry C.M., Lippert R., Walenz B., Shatkay H., Dew I., Miller J.R., Flanigan M.J., Edwards N.J., Bolanos R., Fasulo D., Halldorsson B.V., Hannenhalli S., Turner R. expand/collapse author list , Yooseph S., Lu F., Nusskern D.R., Shue B.C., Zheng X.H., Zhong F., Delcher A.L., Huson D.H., Kravitz S.A., Mouchard L., Reinert K., Remington K.A., Clark A.G., Waterman M.S., Eichler E.E., Adams M.D., Hunkapiller M.W., Myers E.W., Venter J.C.
Submitted (SEP-2005) to the EMBL/GenBank/DDBJ databases
Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
[10]"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] (ISOFORM 2).
Tissue: Pancreas.
[11]"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.
[12]"Acute activation of Maxi-K channels (hSlo) by estradiol binding to the beta subunit."
Valverde M.A., Rojas P., Amigo J., Cosmelli D., Orio P., Bahamonde M.I., Mann G.E., Vergara C., Latorre R.
Science 285:1929-1931(1999) [PubMed] [Europe PMC] [Abstract]
Cited for: BINDING TO E2.
[13]"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.
[14]"Gain-of-function mutation in the KCNMB1 potassium channel subunit is associated with low prevalence of diastolic hypertension."
Fernandez-Fernandez J.M., Tomas M., Vazquez E., Orio P., Latorre R., Senti M., Marrugat J., Valverde M.A.
J. Clin. Invest. 113:1032-1039(2004) [PubMed] [Europe PMC] [Abstract]
Cited for: VARIANT LYS-65.
+Additional computationally mapped references.

Cross-references

Sequence databases

EMBL
GenBank
DDBJ
U25138 mRNA. Translation: AAB02394.1.
U38907 mRNA. Translation: AAA81327.1.
U42600 mRNA. Translation: AAB16827.1.
U42601 Genomic DNA. Translation: AAB16825.1.
U42603, U42602 Genomic DNA. Translation: AAB16826.1.
U61536 mRNA. Translation: AAB61396.1.
U61537 Genomic DNA. Translation: AAB61397.1.
AF026002 mRNA. Translation: AAB88805.1.
AY044441 mRNA. Translation: AAK95827.1.
AY515264 mRNA. Translation: AAS20193.1.
AK313979 mRNA. Translation: BAG36693.1.
CH471062 Genomic DNA. Translation: EAW61474.1.
BC025707 mRNA. Translation: AAH25707.1.
PIRS68842.
RefSeqNP_004128.1. NM_004137.3.
UniGeneHs.484099.
Hs.744947.

3D structure databases

ProteinModelPortalQ16558.
ModBaseSearch...
MobiDBSearch...

Protein-protein interaction databases

BioGrid109980. 4 interactions.
IntActQ16558. 1 interaction.
MINTMINT-1470084.
STRING9606.ENSP00000274629.

Chemistry

BindingDBQ16558.

Protein family/group databases

TCDB8.A.14.1.2. the ca(2+)-activated k(+) channel auxiliary subunit slowpoke- (slo) family.

PTM databases

PhosphoSiteQ16558.

Polymorphism databases

DMDM292495100.

Proteomic databases

PRIDEQ16558.

Protocols and materials databases

StructuralBiologyKnowledgebaseSearch...

Genome annotation databases

EnsemblENST00000274629; ENSP00000274629; ENSG00000145936. [Q16558-1]
ENST00000521859; ENSP00000427940; ENSG00000145936. [Q16558-2]
GeneID3779.
KEGGhsa:3779.
UCSCuc003maq.2. human. [Q16558-1]
uc003mar.4. human. [Q16558-2]

Organism-specific databases

CTD3779.
GeneCardsGC05M169737.
HGNCHGNC:6285. KCNMB1.
HPAHPA020435.
MIM603951. gene.
608622. phenotype.
neXtProtNX_Q16558.
PharmGKBPA221.
GenAtlasSearch...

Phylogenomic databases

eggNOGNOG40171.
HOVERGENHBG052223.
InParanoidQ16558.
KOK04937.
OMAIIAMVKI.
OrthoDBEOG77WWDC.
PhylomeDBQ16558.
TreeFamTF328589.

Enzyme and pathway databases

ReactomeREACT_13685. Neuronal System.
REACT_604. Hemostasis.

Gene expression databases

BgeeQ16558.
CleanExHS_KCNMB1.
GenevestigatorQ16558.

Family and domain databases

InterProIPR003930. K_chnl_Ca-activ_BK_bsu.
[Graphical view]
PANTHERPTHR10258. PTHR10258. 1 hit.
PfamPF03185. CaKB. 1 hit.
[Graphical view]
PRINTSPR01450. BKCHANNELB.
ProtoNetSearch...

Other

GeneWikiKCNMB1.
GenomeRNAi3779.
NextBio14829.
PROQ16558.
SOURCESearch...

Entry information

Entry nameKCMB1_HUMAN
AccessionPrimary (citable) accession number: Q16558
Secondary accession number(s): O00707 expand/collapse secondary AC list , O00708, P78475, Q53YR0, Q8TAX3, Q93005
Entry history
Integrated into UniProtKB/Swiss-Prot: November 1, 1997
Last sequence update: March 23, 2010
Last modified: April 16, 2014
This is version 117 of the entry and version 5 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

MIM cross-references

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

Human polymorphisms and disease mutations

Index of human polymorphisms and disease mutations

Human entries with polymorphisms or disease mutations

List of human entries with polymorphisms or disease mutations

Human chromosome 5

Human chromosome 5: entries, gene names and cross-references to MIM