Q811Q0 (KCMB2_RAT) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names

Recommended name:
Calcium-activated potassium channel subunit beta-2

Alternative name(s):
BK channel subunit beta-2
Short name=BKbeta2
Calcium-activated potassium channel, subfamily M subunit beta-2
Charybdotoxin receptor subunit beta-2
K(VCA)beta-2
Maxi K channel subunit beta-2
Rbeta3
Slo-beta-2

Gene names

Name:

Kcnmb2

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	235 AA.
Sequence status	Complete.
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. Acts as a negative regulator that confers rapid and complete inactivation of KCNMA1 channel complex By similarity.
Subunit structure	Interacts with KCNMA1 tetramer. There are probably 4 molecules of KCMNB2 per KCNMA1 tetramer By similarity.
Subcellular location	Membrane; Multi-pass membrane protein By similarity.
Tissue specificity	Highly expressed in brain and heart. Also expressed in lung. Ref.3
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 By similarity.
Post-translational modification	N-glycosylated By similarity.
Sequence similarities	Belongs to the KCNMB (TC 8.A.14.1) family. KCNMB2 subfamily. [View classification]

Ontologies

Keywords
Biological process	Ion transport Transport
Cellular component	Membrane
Domain	Transmembrane Transmembrane helix
Molecular function	Ion channel
PTM	Glycoprotein
Technical term	Complete proteome Reference proteome
Gene Ontology (GO)
Cellular_component	integral to membrane Inferred from electronic annotation. Source: UniProtKB-KW
Molecular_function	calcium-activated potassium channel activity Inferred from electronic annotation. Source: InterPro potassium channel activity Inferred from direct assay Ref.2. Source: RGD
Complete GO annotation...

Sequence annotation (Features)

	Feature key	Position(s)	Length	Description	Graphical view	Feature identifier
Molecule processing
	Chain	1 – 235	235	Calcium-activated potassium channel subunit beta-2		PRO_0000187053
Regions
	Topological domain	1 – 46	46	Cytoplasmic Potential
	Transmembrane	47 – 67	21	Helical; Name=1; Potential
	Topological domain	68 – 194	127	Extracellular Potential
	Transmembrane	195 – 215	21	Helical; Name=2; Potential
	Topological domain	216 – 235	20	Cytoplasmic Potential
	Region	1 – 45	45	Ball and chain
Amino acid modifications
	Glycosylation	88	1	N-linked (GlcNAc...) Potential
	Glycosylation	96	1	N-linked (GlcNAc...) Potential
	Glycosylation	119	1	N-linked (GlcNAc...) Potential
Experimental info
	Sequence conflict	84	1	R → C in CAD56888. Ref.2

Sequences

	Sequence		Length	Mass (Da)
	Q811Q0 [UniParc]. Last modified June 1, 2003. Version 1. Checksum: E111B041867A3F70	FASTA	235	27,154
	10 20 30 40 50 60 MFIWTSGRTS SSYRHDEKRN IYQKIRDHDL LDKRKTVTAL KAGEDRAILL GLAMMVCSIM 70 80 90 100 110 120 MYFLLGITLL RSYMQSVWTE EAQRALLNVS ITETFNCSFS CGPDCWKLSQ YPCLQVYVNL 130 140 150 160 170 180 TSSGEKLLLY HTEETMKINQ KCSYIPKCGN NFEESMSLVS VVMENFRRHQ HFPCYSDPEG 190 200 210 220 230 NQKSVILTKL YSSNVLFHSL FWPTCMMAGG VAIVAMVKLT QYLSLLCERI QRINR

References

[1]	"Rat inactivating beta 2 subunit of large conductance Ca2+-activated K+ channel (KCNMB2, rSlo beta 2 subunit)." Eghbali M., Foroughi S., Toro L., Stefani E. Submitted (DEC-2002) to the EMBL/GenBank/DDBJ databases Cited for: NUCLEOTIDE SEQUENCE [MRNA]. Strain: Sprague-Dawley. Tissue: Heart.
[2]	"Expression of a Ca2+-activated BK channel mRNA and its splice variants in the rat cochlea." Langer P., Gruender S., Ruesch A. J. Comp. Neurol. 455:198-209(2003) [PubMed] [Europe PMC] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA] OF 40-201. Strain: Wistar. Tissue: Brain.
[3]	"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: TISSUE SPECIFICITY.

Cross-references

Sequence databases
EMBL GenBank DDBJ	AY191836 mRNA. Translation: AAO43501.1. AJ517198 mRNA. Translation: CAD56888.1.
IPI	IPI00195117.
RefSeq	NP_789831.1. NM_176861.1.
UniGene	Rn.220612. Rn.92476.
3D structure databases
ProteinModelPortal	Q811Q0.
SMR	Q811Q0. Positions 1-45.
ModBase	Search...
Proteomic databases
PRIDE	Q811Q0.
Protocols and materials databases
StructuralBiologyKnowledgebase	Search...
Genome annotation databases
GeneID	294961.
KEGG	rno:294961.
UCSC	RGD:631398. rat.
Organism-specific databases
CTD	10242.
RGD	631398. Kcnmb2.
Phylogenomic databases
eggNOG	NOG44064.
HOGENOM	HOG000290180.
HOVERGEN	HBG052223.
InParanoid	Q811Q0.
KO	K04938.
Gene expression databases
Genevestigator	Q811Q0.
Family and domain databases
Gene3D	4.10.81.20. 1 hit.
InterPro	IPR003930. K_chnl_Ca-activ_BK_bsu. IPR015382. KCNMB2_ball_chain_dom. [Graphical view]
PANTHER	PTHR10258. PTHR10258. 1 hit.
Pfam	PF03185. CaKB. 1 hit. PF09303. KcnmB2_inactiv. 1 hit. [Graphical view]
PRINTS	PR01450. BKCHANNELB.
ProtoNet	Search...
Other
NextBio	638780.

Entry information

Entry name

KCMB2_RAT

Accession

Primary (citable) accession number: Q811Q0
Secondary accession number(s): Q8CF83

Entry history

Integrated into UniProtKB/Swiss-Prot:	April 13, 2004
Last sequence update:	June 1, 2003
Last modified:	April 3, 2013
This is version 66 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Chordata Protein Annotation Program