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Protein

Calcium-activated potassium channel subunit beta-1

Gene

KCNMB1

Organism
Homo sapiens (Human)
Status
Reviewed-Annotation score: -Experimental evidence at protein leveli

Functioni

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.

GO - Molecular functioni

GO - Biological processi

Keywordsi

Molecular functionIon channel
Biological processIon transport, Transport

Enzyme and pathway databases

ReactomeiR-HSA-1296052 Ca2+ activated K+ channels
R-HSA-418457 cGMP effects

Protein family/group databases

TCDBi8.A.14.1.2 the ca(2+)-activated k(+) channel auxiliary subunit slowpoke-Beta (sloBeta) family

Names & Taxonomyi

Protein namesi
Recommended 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 namesi
Name:KCNMB1
OrganismiHomo sapiens (Human)
Taxonomic identifieri9606 [NCBI]
Taxonomic lineageiEukaryotaMetazoaChordataCraniataVertebrataEuteleostomiMammaliaEutheriaEuarchontogliresPrimatesHaplorrhiniCatarrhiniHominidaeHomo
Proteomesi
  • UP000005640 Componenti: Chromosome 5

Organism-specific databases

EuPathDBiHostDB:ENSG00000145936.8
HGNCiHGNC:6285 KCNMB1
MIMi603951 gene
neXtProtiNX_Q16558

Subcellular locationi

Extracellular region or secreted Cytosol Plasma membrane Cytoskeleton Lysosome Endosome Peroxisome ER Golgi apparatus Nucleus Mitochondrion Manual annotation Automatic computational assertionGraphics by Christian Stolte; Source: COMPARTMENTS

Topology

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Topological domaini1 – 18CytoplasmicSequence analysisAdd BLAST18
Transmembranei19 – 39Helical; Name=1Sequence analysisAdd BLAST21
Topological domaini40 – 157ExtracellularSequence analysisAdd BLAST118
Transmembranei158 – 178Helical; Name=2Sequence analysisAdd BLAST21
Topological domaini179 – 191CytoplasmicSequence analysisAdd BLAST13

Keywords - Cellular componenti

Membrane

Pathology & Biotechi

Organism-specific databases

DisGeNETi3779
MalaCardsiKCNMB1
MIMi608622 phenotype
OpenTargetsiENSG00000145936
PharmGKBiPA221

Chemistry databases

ChEMBLiCHEMBL3038495
DrugBankiDB01110 Miconazole
DB00721 Procaine

Polymorphism and mutation databases

DMDMi292495100

PTM / Processingi

Molecule processing

Feature keyPosition(s)DescriptionActionsGraphical viewLength
ChainiPRO_00001870461 – 191Calcium-activated potassium channel subunit beta-1Add BLAST191

Amino acid modifications

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Glycosylationi80N-linked (GlcNAc...) asparagineSequence analysis1
Glycosylationi142N-linked (GlcNAc...) asparagineSequence analysis1

Post-translational modificationi

N-glycosylated.1 Publication

Keywords - PTMi

Glycoprotein

Proteomic databases

PaxDbiQ16558
PeptideAtlasiQ16558
PRIDEiQ16558
ProteomicsDBi60914
60915 [Q16558-2]

PTM databases

PhosphoSitePlusiQ16558

Expressioni

Tissue specificityi

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.

Gene expression databases

BgeeiENSG00000145936
CleanExiHS_KCNMB1
GenevisibleiQ16558 HS

Interactioni

Subunit structurei

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

Protein-protein interaction databases

BioGridi109980, 4 interactors
IntActiQ16558, 2 interactors
STRINGi9606.ENSP00000274629

Structurei

3D structure databases

ProteinModelPortaliQ16558
ModBaseiSearch...
MobiDBiSearch...

Family & Domainsi

Sequence similaritiesi

Keywords - Domaini

Transmembrane, Transmembrane helix

Phylogenomic databases

eggNOGiENOG410IWME Eukaryota
ENOG41116AX LUCA
GeneTreeiENSGT00390000015997
HOVERGENiHBG052223
InParanoidiQ16558
KOiK04937
OMAiMLYHTED
OrthoDBiEOG091G0MVO
PhylomeDBiQ16558
TreeFamiTF328589

Family and domain databases

InterProiView protein in InterPro
IPR003930 K_chnl_Ca-activ_BK_bsu
PANTHERiPTHR10258 PTHR10258, 1 hit
PfamiView protein in Pfam
PF03185 CaKB, 1 hit
PRINTSiPR01450 BKCHANNELB

Sequences (2)i

Sequence statusi: Complete.

This entry describes 2 isoformsi produced by alternative splicing. AlignAdd to basket

Isoform 1 (identifier: Q16558-1) [UniParc]FASTAAdd to basket

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.

« Hide

        10         20         30         40         50
MVKKLVMAQK RGETRALCLG VTMVVCAVIT YYILVTTVLP LYQKSVWTQE
60 70 80 90 100
SKCHLIETNI RDQEELKGKK VPQYPCLWVN VSAAGRWAVL YHTEDTRDQN
110 120 130 140 150
QQCSYIPGSV DNYQTARADV EKVRAKFQEQ QVFYCFSAPR GNETSVLFQR
160 170 180 190
LYGPQALLFS LFWPTFLLTG GLLIIAMVKS NQYLSILAAQ K
Length:191
Mass (Da):21,797
Last modified:March 23, 2010 - v5
Checksum:i547432FF194E770D
GO
Isoform 2 (identifier: Q16558-2) [UniParc]FASTAAdd to basket

The sequence of this isoform differs from the canonical sequence as follows:
     103-130: CSYIPGSVDNYQTARADVEKVRAKFQEQ → VLNWRDGDTSLYPCQVCEPVPNCPCPRG
     131-191: Missing.

Note: No experimental confirmation available.
Show »
Length:130
Mass (Da):14,858
Checksum:i2E612865F4130EEE
GO

Polymorphismi

Genetic variation in KCNMB1 can influence the severity of diastolic hypertension (PubMed:15057310).1 Publication

Natural variant

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Natural variantiVAR_01932565E → K Has a protective effect against diastolic hypertension. 1 PublicationCorresponds to variant dbSNP:rs11739136EnsemblClinVar.1
Natural variantiVAR_047009110V → L. Corresponds to variant dbSNP:rs2301149Ensembl.1

Alternative sequence

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Alternative sequenceiVSP_009822103 – 130CSYIP…KFQEQ → VLNWRDGDTSLYPCQVCEPV PNCPCPRG in isoform 2. 1 PublicationAdd BLAST28
Alternative sequenceiVSP_009823131 – 191Missing in isoform 2. 1 PublicationAdd BLAST61

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
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
CCDSiCCDS4373.1 [Q16558-1]
PIRiS68842
RefSeqiNP_004128.1, NM_004137.3 [Q16558-1]
UniGeneiHs.484099
Hs.744947

Genome annotation databases

EnsembliENST00000274629; ENSP00000274629; ENSG00000145936 [Q16558-1]
ENST00000521859; ENSP00000427940; ENSG00000145936 [Q16558-2]
GeneIDi3779
KEGGihsa:3779
UCSCiuc003maq.3 human [Q16558-1]

Keywords - Coding sequence diversityi

Alternative splicing, Polymorphism

Similar proteinsi

Entry informationi

Entry nameiKCMB1_HUMAN
AccessioniPrimary (citable) accession number: Q16558
Secondary accession number(s): O00707
, O00708, P78475, Q53YR0, Q8TAX3, Q93005
Entry historyiIntegrated into UniProtKB/Swiss-Prot: November 1, 1997
Last sequence update: March 23, 2010
Last modified: July 18, 2018
This is version 152 of the entry and version 5 of the sequence. See complete history.
Entry statusiReviewed (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.

Miscellaneousi

Keywords - Technical termi

Complete proteome, Reference proteome

Documents

  1. Human chromosome 5
    Human chromosome 5: entries, gene names and cross-references to MIM
  2. Human entries with polymorphisms or disease mutations
    List of human entries with polymorphisms or disease mutations
  3. Human polymorphisms and disease mutations
    Index of human polymorphisms and disease mutations
  4. MIM cross-references
    Online Mendelian Inheritance in Man (MIM) cross-references in UniProtKB/Swiss-Prot
  5. SIMILARITY comments
    Index of protein domains and families

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