Q16558 (KCMB1_HUMAN) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names

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 names

Name:

KCNMB1

Organism

Homo sapiens (Human) [Reference proteome]

Taxonomic identifier

9606 [NCBI]

Taxonomic lineage

cellular organisms › Eukaryota › Opisthokonta › Metazoa › Eumetazoa › Bilateria › Deuterostomia › Chordata › Craniata › Vertebrata › Gnathostomata › Teleostomi › Euteleostomi › Sarcopterygii › Tetrapoda › Amniota › Mammalia › Theria › Eutheria › Euarchontoglires › Primates › Haplorrhini › Simiiformes › Catarrhini › Hominoidea › Hominidae › Homininae › Homo

Protein attributes

Sequence length	191 AA.
Sequence status	Complete.
Sequence processing	The displayed sequence is further processed into a mature form.
Protein existence	Evidence 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]

Ontologies

Keywords
Biological process	Ion transport Transport
Cellular component	Membrane
Coding sequence diversity	Alternative splicing Polymorphism
Domain	Transmembrane Transmembrane helix
Molecular function	Ion channel
PTM	Glycoprotein
Technical term	Complete proteome Reference proteome
Gene Ontology (GO)
Biological_process	blood coagulation Traceable author statement. Source: Reactome response to calcium ion Inferred from electronic annotation. Source: Compara synaptic transmission Traceable author statement. Source: Reactome
Cellular_component	plasma membrane Traceable author statement. Source: Reactome voltage-gated potassium channel complex Inferred from electronic annotation. Source: Compara
Molecular_function	calcium-activated potassium channel activity Traceable author statement Ref.1. Source: ProtInc potassium channel regulator activity Traceable author statement Ref.1. Source: ProtInc
Complete GO annotation...

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 key	Position(s)	Length	Description	Graphical view	Feature identifier
Molecule processing
	Initiator methionine	1	1	Removed By similarity
	Chain	2 – 191	190	Calcium-activated potassium channel subunit beta-1		PRO_0000187046
Regions
	Topological domain	2 – 18	17	Cytoplasmic Potential
	Transmembrane	19 – 39	21	Helical; Name=1; Potential
	Topological domain	40 – 157	118	Extracellular Potential
	Transmembrane	158 – 178	21	Helical; Name=2; Potential
	Topological domain	179 – 191	13	Cytoplasmic Potential
Amino acid modifications
	Glycosylation	80	1	N-linked (GlcNAc...) Potential
	Glycosylation	142	1	N-linked (GlcNAc...) Potential
Natural variations
	Alternative sequence	103 – 130	28	CSYIP…KFQEQ → VLNWRDGDTSLYPCQVCEPV PNCPCPRG in isoform 2.		VSP_009822
	Alternative sequence	131 – 191	61	Missing in isoform 2.		VSP_009823
	Natural variant	65	1	E → K Has a protective effect against diastolic hypertension. Ref.14 Corresponds to variant rs11739136 [ dbSNP | Ensembl ].		VAR_019325
	Natural variant	110	1	V → L. Corresponds to variant rs2301149 [ dbSNP | Ensembl ].		VAR_047009

Sequences

	Sequence		Length	Mass (Da)
	Isoform 1 [UniParc]. Last modified March 23, 2010. Version 5. Checksum: 547432FF194E770D	FASTA	191	21,797
	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
	Isoform 2 [UniParc]. Checksum: 2E612865F4130EEE	FASTA	130	14,858
	10 20 30 40 50 60 MVKKLVMAQK RGETRALCLG VTMVVCAVIT YYILVTTVLP LYQKSVWTQE SKCHLIETNI 70 80 90 100 110 120 RDQEELKGKK VPQYPCLWVN VSAAGRWAVL YHTEDTRDQN QQVLNWRDGD TSLYPCQVCE 130 PVPNCPCPRG

References

	« Hide 'large scale' referencesShow '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. , 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. , 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.
IPI	IPI00748067. IPI00828136.
PIR	S68842.
RefSeq	NP_004128.1. NM_004137.3.
UniGene	Hs.484099.
3D structure databases
ProteinModelPortal	Q16558.
ModBase	Search...
Protein-protein interaction databases
IntAct	Q16558. 1 interaction.
MINT	MINT-1470084.
STRING	9606.ENSP00000274629.
Protein family/group databases
TCDB	8.A.14.1.2. Ca2+-activated K+ channel auxiliary subunit slowpoke-beta (Slobeta) family.
PTM databases
PhosphoSite	Q16558.
Polymorphism databases
DMDM	292495100.
Proteomic databases
PRIDE	Q16558.
Protocols and materials databases
StructuralBiologyKnowledgebase	Search...
Genome annotation databases
Ensembl	ENST00000274629; ENSP00000274629; ENSG00000145936. ENST00000521859; ENSP00000427940; ENSG00000145936.
GeneID	3779.
KEGG	hsa:3779.
UCSC	uc003maq.1. human. uc003mar.3. human.
Organism-specific databases
CTD	3779.
GeneCards	GC05M169737.
HGNC	HGNC:6285. KCNMB1.
HPA	HPA020435.
MIM	603951. gene. 608622. phenotype.
neXtProt	NX_Q16558.
PharmGKB	PA221.
GenAtlas	Search...
Phylogenomic databases
eggNOG	NOG40171.
HOVERGEN	HBG052223.
InParanoid	Q16558.
KO	K04937.
OMA	YQRLYGP.
OrthoDB	EOG47SSFT.
PhylomeDB	Q16558.
Enzyme and pathway databases
Reactome	REACT_13685. Neuronal System. REACT_604. Hemostasis.
Gene expression databases
Bgee	Q16558.
CleanEx	HS_KCNMB1.
Genevestigator	Q16558.
GermOnline	ENSG00000145936. Homo sapiens.
Family and domain databases
InterPro	IPR003930. K_chnl_Ca-activ_BK_bsu. [Graphical view]
PANTHER	PTHR10258. PTHR10258. 1 hit.
Pfam	PF03185. CaKB. 1 hit. [Graphical view]
PRINTS	PR01450. BKCHANNELB.
ProtoNet	Search...
Other
BindingDB	Q16558.
ChEMBL	CHEMBL5078.
GenomeRNAi	3779.
NextBio	14829.
SOURCE	Search...

Entry information

Entry name

KCMB1_HUMAN

Accession

Primary (citable) accession number: Q16558
Secondary accession number(s): O00707 , O00708, P78475, Q53YR0, Q8TAX3, Q93005

Entry history

Integrated into UniProtKB/Swiss-Prot:	November 1, 1997
Last sequence update:	March 23, 2010
Last modified:	May 1, 2013
This is version 107 of the entry and version 5 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Chordata Protein Annotation Program

Disclaimer

Any 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.