P97678 (KCMB1_RAT) 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
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
Slowpoke-beta

Gene names

Name:

Kcnmb1

Organism

Rattus norvegicus (Rat) [Reference proteome]

Taxonomic identifier

10116 [NCBI]

Taxonomic lineage

cellular organisms › Eukaryota › Opisthokonta › Metazoa › Eumetazoa › Bilateria › Deuterostomia › Chordata › Craniata › Vertebrata › Gnathostomata › Teleostomi › Euteleostomi › Sarcopterygii › Tetrapoda › Amniota › Mammalia › Theria › Eutheria › Euarchontoglires › Glires › Rodentia › Sciurognathi › Muroidea › Muridae › Murinae › Rattus

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 transcript 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 By similarity.
Subunit structure	Interacts with KCNMA1 tetramer. There are probably 4 molecules of KCMNB1 per KCNMA1 tetramer By similarity.
Subcellular location	Membrane; Multi-pass membrane protein.
Tissue specificity	Weakly expressed. In brain, it is expressed in a few discrete populations of neurons that also express KCNMA1. Ref.1
Post-translational modification	N-glycosylated By similarity.
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
Domain	Transmembrane Transmembrane helix
Molecular function	Ion channel
PTM	Glycoprotein
Technical term	Complete proteome Reference proteome
Gene Ontology (GO)
Biological_process	response to calcium ion Inferred from direct assay Ref.2. Source: RGD
Cellular_component	voltage-gated potassium channel complex Inferred from electronic annotation. Source: Compara
Molecular_function	calcium-activated potassium channel activity Traceable author statement Ref.1. Source: RGD potassium channel regulator activity Inferred from direct assay Ref.2. Source: RGD
Complete GO annotation...

Alternative products

This entry describes 3 isoforms produced by alternative splicing. [Align] [Select]

Isoform 1 (identifier: P97678-1)

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: P97678-2)

Also known as: 1b;

The sequence of this isoform differs from the canonical sequence as follows:
     123-146: VRANFYKHHNFYCFSAPQVNETSV → LRSRPISSAQQHGVTRNGRGPGQA
     147-191: Missing.

Isoform 3 (identifier: P97678-3)

Also known as: 1c;

The sequence of this isoform differs from the canonical sequence as follows:
     103-122: Missing.
     123-146: VRANFYKHHNFYCFSAPQVNETSV → LRSRPISSAQQHGVTRNGRGPGQA
     147-191: Missing.

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_0000187049
Regions
	Topological domain	2 – 18	17	Cytoplasmic Potential
	Transmembrane	19 – 39	21	Helical; Name=1; Potential
	Topological domain	40 – 155	116	Extracellular Potential
	Transmembrane	156 – 176	21	Helical; Name=2; Potential
	Topological domain	177 – 191	15	Cytoplasmic Potential
Amino acid modifications
	Glycosylation	80	1	N-linked (GlcNAc...) Potential
	Glycosylation	142	1	N-linked (GlcNAc...) Potential
Natural variations
	Alternative sequence	103 – 122	20	Missing in isoform 3.		VSP_009824
	Alternative sequence	123 – 146	24	VRANF…NETSV → LRSRPISSAQQHGVTRNGRG PGQA in isoform 2 and isoform 3.		VSP_009825
	Alternative sequence	147 – 191	45	Missing in isoform 2 and isoform 3.		VSP_009826
Experimental info
	Sequence conflict	14	1	T → A in AAB38413. Ref.2
	Sequence conflict	28 – 30	3	AIT → VVA in AAB38413. Ref.2
	Sequence conflict	38	1	V → M in AAB38413. Ref.2
	Sequence conflict	56 – 61	6	VETNIK → IESNIR in AAB38413. Ref.2
	Sequence conflict	69	1	R → K in AAB38413. Ref.2
	Sequence conflict	89	1	M → V in AAB38413. Ref.2
	Sequence conflict	105	1	Y → H in AAD11548. Ref.1
	Sequence conflict	109 – 111	3	NLD → SLE in AAB38413. Ref.2
	Sequence conflict	115 – 121	7	TALVDVK → VARADVE in AAB38413. Ref.2
	Sequence conflict	125	1	A → T in AAB38413. Ref.2
	Sequence conflict	128 – 132	5	YKHHN → HEHRI in AAB38413. Ref.2
	Sequence conflict	138 – 141	4	APQV → TTRE in AAB38413. Ref.2
	Sequence conflict	145 – 149	5	SVVYQ → TVLYR in AAB38413. Ref.2
	Sequence conflict	156	1	I → T in AAB38413. Ref.2
	Sequence conflict	161	1	F → L in AAB38413. Ref.2
	Sequence conflict	177	1	M → I in AAD11548. Ref.1
	Sequence conflict	180 – 182	3	LNR → INQ in AAB38413. Ref.2
	Sequence conflict	186 – 187	2	VL → IP in AAD11548. Ref.1
	Sequence conflict	186	1	V → I in AAB38413. Ref.2
	Sequence conflict	191	1	K → R Ref.1
	Sequence conflict	191	1	K → R Ref.2

Sequences

	Sequence		Length	Mass (Da)
	Isoform 1 [UniParc]. Last modified January 23, 2007. Version 4. Checksum: D39F2FE4D69D7662	FASTA	191	21,909
	10 20 30 40 50 60 MGKKLVMAQK RGETRALCLG VAMVVCAAIT YYILGTTVLP LYQKSVWTQE STCHLVETNI 70 80 90 100 110 120 KDQEELEGRK VPQYPCLWVN VSAVGRWAML YHTEDTRDQN QQCSYIPRNL DNYQTALVDV 130 140 150 160 170 180 KKVRANFYKH HNFYCFSAPQ VNETSVVYQR LYGPQILLFS FFWPTFLLTG GLLIIAMVKL 190 NRSLSVLAAQ K
	Isoform 2 (1b) [UniParc]. Checksum: 6EF4D5EA24D68E57	FASTA	146	16,470
	10 20 30 40 50 60 MGKKLVMAQK RGETRALCLG VAMVVCAAIT YYILGTTVLP LYQKSVWTQE STCHLVETNI 70 80 90 100 110 120 KDQEELEGRK VPQYPCLWVN VSAVGRWAML YHTEDTRDQN QQCSYIPRNL DNYQTALVDV 130 140 KKLRSRPISS AQQHGVTRNG RGPGQA
	Isoform 3 (1c) [UniParc]. Checksum: 8B319BB95CE4E8CC	FASTA	126	14,147
	10 20 30 40 50 60 MGKKLVMAQK RGETRALCLG VAMVVCAAIT YYILGTTVLP LYQKSVWTQE STCHLVETNI 70 80 90 100 110 120 KDQEELEGRK VPQYPCLWVN VSAVGRWAML YHTEDTRDQN QQLRSRPISS AQQHGVTRNG RGPGQA

References

[1]	"Differential expression of the alpha and beta subunits of the large-conductance calcium-activated potassium channel: implication for channel diversity." Chang C.-P., Dworetzky S.I., Wang J., Goldstein M.E. Brain Res. Mol. Brain Res. 45:33-40(1997) [PubMed] [Europe PMC] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA] (ISOFORM 1), TISSUE SPECIFICITY. Strain: Sprague-Dawley.
[2]	"Human and rodent MaxiK channel beta-subunit genes: cloning and characterization." Jiang Z., Wallner M., Meera P., Toro L. Genomics 55:57-67(1999) [PubMed] [Europe PMC] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA] (ISOFORM 1). Strain: Sprague-Dawley. Tissue: Uterus.
[3]	Lange A.R., Gebremedhin D., Aebly M., Harder D.R. Submitted (DEC-1996) to the EMBL/GenBank/DDBJ databases Cited for: NUCLEOTIDE SEQUENCE [MRNA] (ISOFORM 1). Strain: Sprague-Dawley. Tissue: Vascular smooth muscle.
[4]	Reimann F. Submitted (NOV-1995) to the EMBL/GenBank/DDBJ databases Cited for: NUCLEOTIDE SEQUENCE [MRNA] (ISOFORM 1). Strain: Sprague-Dawley. Tissue: Uterus.
[5]	"Molecular cloning of a novel spliced variant of calcium activated potassium channel beta subunit in rat smooth muscle." Ohya S., Watanabe M., Imaizumi Y. Submitted (FEB-1998) to the EMBL/GenBank/DDBJ databases Cited for: NUCLEOTIDE SEQUENCE [MRNA] (ISOFORMS 2 AND 3). Tissue: Aorta.
+	Additional computationally mapped references.

Cross-references

Sequence databases
EMBL GenBank DDBJ	U54498 mRNA. Translation: AAD11548.1. AF020712 mRNA. Translation: AAD11858.1. U79661 mRNA. Translation: AAB38413.1. U40602 mRNA. Translation: AAB96355.1. AB010963 mRNA. Translation: BAA33448.1. AB050745 mRNA. Translation: BAB17678.1.
IPI	IPI00192066. IPI00208354. IPI00411289.
RefSeq	NP_062146.1. NM_019273.1. NP_071539.1. NM_022203.1.
UniGene	Rn.10820. Rn.127785.
3D structure databases
ModBase	Search...
Protein-protein interaction databases
STRING	10116.ENSRNOP00000007408.
Protocols and materials databases
StructuralBiologyKnowledgebase	Search...
Genome annotation databases
Ensembl	ENSRNOT00000007393; ENSRNOP00000007393; ENSRNOG00000005465. ENSRNOT00000007408; ENSRNOP00000007408; ENSRNOG00000005465.
GeneID	29747. 60591.
KEGG	rno:29747. rno:60591.
UCSC	RGD:2961. rat.
Organism-specific databases
CTD	3779.
RGD	2961. Kcnmb1.
Phylogenomic databases
eggNOG	NOG40171.
GeneTree	ENSGT00390000015997.
HOGENOM	HOG000290180.
HOVERGEN	HBG052223.
KO	K04937.
OMA	ESSIRHQ.
OrthoDB	EOG47SSFT.
Gene expression databases
Genevestigator	P97678.
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	P97678.
NextBio	610265.

Entry information

Entry name

KCMB1_RAT

Accession

Primary (citable) accession number: P97678
Secondary accession number(s): O35337 , O88805, Q9ESK7, Q9QWI7

Entry history

Integrated into UniProtKB/Swiss-Prot:	November 1, 1997
Last sequence update:	January 23, 2007
Last modified:	April 3, 2013
This is version 84 of the entry and version 4 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Chordata Protein Annotation Program