Q9ESK8 (KCMB4_RAT) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names

Recommended name:
Calcium-activated potassium channel subunit beta-4

Alternative name(s):
BK channel subunit beta-4
Short name=BKbeta4
Calcium-activated potassium channel, subfamily M subunit beta-4
Charybdotoxin receptor subunit beta-4
K(VCA)beta-4
Maxi K channel subunit beta-4
Slo-beta-4

Gene names

Name:

Kcnmb4

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	210 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. Decreases the gating kinetics and calcium sensitivity of the KCNMA1 channel, but with fast deactivation kinetics. May decrease KCNMA1 channel openings at low calcium concentrations but increases channel openings at high calcium concentrations. Makes KCNMA1 channel resistant to 100 nM charybdotoxin (CTX) toxin concentrations By similarity.
Subunit structure	Interacts with KCNMA1 tetramer. There are probably 4 molecules of KCMNB4 per KCNMA1 tetramer By similarity.
Subcellular location	Membrane; Multi-pass membrane protein By similarity.
Domain	Resistance to charybdotoxin (CTX) toxin is mediated by the extracellular domain By similarity.
Post-translational modification	Phosphorylated. Phosphorylation modulates its effect on KCNMA1 activation kinetics By similarity. N-glycosylated. A highly glycosylated form is promoted by KCNMA1. Glycosylation, which is not required for the interaction with KCNMA1 and subcellular location, increases protection against charybdotoxin By similarity.
Sequence similarities	Belongs to the KCNMB (TC 8.A.14.1) family. KCNMB4 subfamily. [View classification]

Ontologies

Keywords
Biological process	Ion transport Transport
Cellular component	Membrane
Domain	Transmembrane Transmembrane helix
Molecular function	Ion channel
PTM	Glycoprotein Phosphoprotein
Technical term	Complete proteome Reference proteome
Gene Ontology (GO)
Biological_process	detection of calcium ion Inferred from sequence or structural similarity. Source: UniProtKB regulation of action potential in neuron Inferred from sequence or structural similarity. Source: UniProtKB
Cellular_component	voltage-gated potassium channel complex Inferred from sequence or structural similarity. Source: UniProtKB
Molecular_function	calcium-activated potassium channel activity Inferred from sequence or structural similarity. Source: UniProtKB
Complete GO annotation...

Sequence annotation (Features)

	Feature key	Position(s)	Length	Description	Graphical view	Feature identifier
Molecule processing
	Chain	1 – 210	210	Calcium-activated potassium channel subunit beta-4		PRO_0000187057
Regions
	Topological domain	1 – 19	19	Cytoplasmic Potential
	Transmembrane	20 – 40	21	Helical; Name=1; Potential
	Topological domain	41 – 167	127	Extracellular Potential
	Transmembrane	168 – 188	21	Helical; Name=2; Potential
	Topological domain	189 – 210	22	Cytoplasmic Potential
Amino acid modifications
	Glycosylation	53	1	N-linked (GlcNAc...) By similarity
	Glycosylation	90	1	N-linked (GlcNAc...) By similarity

Sequences

	Sequence		Length	Mass (Da)
	Q9ESK8 [UniParc]. Last modified March 1, 2001. Version 1. Checksum: 11D49F58F9C6F1D4	FASTA	210	23,885
	10 20 30 40 50 60 MAKLRVSYEY TEAEDKSIRL GLFLIVSGIL SLFIFGFCWL SPALQDLQAT AANCTVLSVQ 70 80 90 100 110 120 QIGEVFECTF TCGTDCRGTS QYPCVQVYVN NSESNSRALL HSDQHQLLTN PKCSYIPPCK 130 140 150 160 170 180 RENQKNSESV MNWQQYWKDE IGSQPFTCYF NQHQRPEDVL LQRTHDEIVL LHCFLWPVVA 190 200 210 FVVGVLIVVL TICAKSLAVK AEAMKKRKFS

References

[1]	"Rat calcium activated potassium channel beta 4 subunit (KCNMB4)." Ohya S., Ohi Y., Imaizumi Y. Submitted (OCT-2000) to the EMBL/GenBank/DDBJ databases Cited for: NUCLEOTIDE SEQUENCE [MRNA]. Tissue: Brain.
[2]	"Molecular cloning of large-conductance calcium-activated potassium channel beta 4 subunit from rat brain." Ha T.S., Park C.-S. Submitted (MAR-2001) to the EMBL/GenBank/DDBJ databases Cited for: NUCLEOTIDE SEQUENCE [MRNA].
+	Additional computationally mapped references.

Cross-references

Sequence databases
EMBL GenBank DDBJ	AB050637 mRNA. Translation: BAB17595.1. AY028605 mRNA. Translation: AAK21964.1.
IPI	IPI00192068.
RefSeq	NP_076450.1. NM_023960.2.
UniGene	Rn.162953.
3D structure databases
ModBase	Search...
Protocols and materials databases
StructuralBiologyKnowledgebase	Search...
Genome annotation databases
GeneID	66016.
KEGG	rno:66016.
UCSC	RGD:620728. rat.
Organism-specific databases
CTD	27345.
RGD	620728. Kcnmb4.
Phylogenomic databases
eggNOG	NOG83271.
HOGENOM	HOG000113205.
HOVERGEN	HBG052224.
InParanoid	Q9ESK8.
KO	K04941.
OrthoDB	EOG4FBHTX.
Gene expression databases
Genevestigator	Q9ESK8.
GermOnline	ENSRNOG00000022297. Rattus norvegicus.
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]
ProtoNet	Search...
Other
NextBio	614292.

Entry information

Entry name

KCMB4_RAT

Accession

Primary (citable) accession number: Q9ESK8

Entry history

Integrated into UniProtKB/Swiss-Prot:	April 13, 2004
Last sequence update:	March 1, 2001
Last modified:	April 3, 2013
This is version 64 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Chordata Protein Annotation Program