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Protein

Calcium-activated potassium channel subunit beta-3

Gene

KCNMB3

Organism
Homo sapiens (Human)
Status
Reviewed-Annotation score: Annotation score: 5 out of 5-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. Alters the functional properties of the current expressed by the KCNMA1 channel. Isoform 2, isoform 3 and isoform 4 partially inactivate the current of KCNBMA. Isoform 4 induces a fast and incomplete inactivation of KCNMA1 channel that is detectable only at large depolarizations. In contrast, isoform 1 does not induce detectable inactivation of KCNMA1. Two or more subunits of KCNMB3 are required to block the KCNMA1 tetramer.2 Publications

GO - Molecular functioni

  • calcium-activated potassium channel activity Source: UniProtKB
  • potassium channel regulator activity Source: UniProtKB

GO - Biological processi

  • action potential Source: UniProtKB
  • chemical synaptic transmission Source: GO_Central
  • detection of calcium ion Source: UniProtKB
  • neuronal action potential Source: UniProtKB
  • potassium ion transport Source: UniProtKB
Complete GO annotation...

Keywords - Molecular functioni

Ion channel

Keywords - Biological processi

Ion transport, Transport

Enzyme and pathway databases

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

Protein family/group databases

TCDBi8.A.14.1.4. the ca(2+)-activated k(+) channel auxiliary subunit slowpoke-Beta (sloBeta) family.

Names & Taxonomyi

Protein namesi
Recommended name:
Calcium-activated potassium channel subunit beta-3
Alternative name(s):
BK channel subunit beta-3
Short name:
BKbeta3
Short name:
Hbeta3
Calcium-activated potassium channel, subfamily M subunit beta-3
Charybdotoxin receptor subunit beta-3
K(VCA)beta-3
Maxi K channel subunit beta-3
Slo-beta-3
Gene namesi
Name:KCNMB3
Synonyms:KCNMB2, KCNMBL
OrganismiHomo sapiens (Human)
Taxonomic identifieri9606 [NCBI]
Taxonomic lineageiEukaryotaMetazoaChordataCraniataVertebrataEuteleostomiMammaliaEutheriaEuarchontogliresPrimatesHaplorrhiniCatarrhiniHominidaeHomo
Proteomesi
  • UP000005640 Componenti: Chromosome 3

Organism-specific databases

HGNCiHGNC:6287. KCNMB3.

Subcellular locationi

Topology

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Topological domaini1 – 60CytoplasmicSequence analysisAdd BLAST60
Transmembranei61 – 81Helical; Name=1Sequence analysisAdd BLAST21
Topological domaini82 – 207ExtracellularSequence analysisAdd BLAST126
Transmembranei208 – 228Helical; Name=2Sequence analysisAdd BLAST21
Topological domaini229 – 279CytoplasmicSequence analysisAdd BLAST51

GO - Cellular componenti

  • integral component of plasma membrane Source: UniProtKB
  • plasma membrane Source: Reactome
  • voltage-gated potassium channel complex Source: UniProtKB
Complete GO annotation...

Keywords - Cellular componenti

Membrane

Pathology & Biotechi

Organism-specific databases

DisGeNETi27094.
OpenTargetsiENSG00000171121.
PharmGKBiPA30067.

Chemistry databases

DrugBankiDB01110. Miconazole.
DB00721. Procaine.

Polymorphism and mutation databases

BioMutaiKCNMB3.
DMDMi90111824.

PTM / Processingi

Molecule processing

Feature keyPosition(s)DescriptionActionsGraphical viewLength
ChainiPRO_00001870541 – 279Calcium-activated potassium channel subunit beta-3Add BLAST279

Amino acid modifications

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Glycosylationi131N-linked (GlcNAc...)Sequence analysis1

Post-translational modificationi

N-glycosylated.1 Publication
The extracellular domain contains disulfide bond essential for the gating mechanism.

Keywords - PTMi

Disulfide bond, Glycoprotein

Proteomic databases

PaxDbiQ9NPA1.
PRIDEiQ9NPA1.

Expressioni

Tissue specificityi

Isoform 1, isoform 3 and isoform 4 are widely expressed. Isoform 2 is expressed placenta, pancreas, kidney and heart. Isoform 1 and isoform 3 are highly expressed in pancreas and testis.3 Publications

Gene expression databases

BgeeiENSG00000171121.
CleanExiHS_KCNMB2.
HS_KCNMB3.
ExpressionAtlasiQ9NPA1. baseline and differential.
GenevisibleiQ9NPA1. HS.

Organism-specific databases

HPAiHPA015665.
HPA019185.

Interactioni

Subunit structurei

Interacts with KCNMA1 tetramer. There are probably 4 molecules of KCMNB3 per KCNMA1 tetramer.1 Publication

Protein-protein interaction databases

STRINGi9606.ENSP00000319370.

Structurei

3D structure databases

ProteinModelPortaliQ9NPA1.
SMRiQ9NPA1.
ModBaseiSearch...
MobiDBiSearch...

Family & Domainsi

Domaini

Isoform 4 cytoplasmic N-terminal domain participates in the partial inactivation of KCNMA1, possibly by binding to a receptor site.
The extracellular domain forms gates to block ion permeation, providing a mechanism by which current can be rapidly diminished upon cellular repolarization.

Sequence similaritiesi

Keywords - Domaini

Transmembrane, Transmembrane helix

Phylogenomic databases

eggNOGiENOG410IF7H. Eukaryota.
ENOG410YQCT. LUCA.
GeneTreeiENSGT00390000015997.
HOGENOMiHOG000290180.
HOVERGENiHBG108059.
InParanoidiQ9NPA1.
KOiK04939.
OMAiKPFMLST.
OrthoDBiEOG091G0MVO.
PhylomeDBiQ9NPA1.
TreeFamiTF328589.

Family and domain databases

InterProiIPR003930. K_chnl_Ca-activ_BK_bsu.
[Graphical view]
PANTHERiPTHR10258. PTHR10258. 1 hit.
PfamiPF03185. CaKB. 1 hit.
[Graphical view]

Sequences (5)i

Sequence statusi: Complete.

This entry describes 5 isoformsi produced by alternative splicing. AlignAdd to basket

Isoform 1 (identifier: Q9NPA1-1) [UniParc]FASTAAdd to basket
Also known as: 3d

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
MDFSPSSELG FHFVAFILLT RHRTAFPASG KKRETDYSDG DPLDVHKRLP
60 70 80 90 100
SSAGEDRAVM LGFAMMGFSV LMFFLLGTTI LKPFMLSIQR EESTCTAIHT
110 120 130 140 150
DIMDDWLDCA FTCGVHCHGQ GKYPCLQVFV NLSHPGQKAL LHYNEEAVQI
160 170 180 190 200
NPKCFYTPKC HQDRNDLLNS ALDIKEFFDH KNGTPFSCFY SPASQSEDVI
210 220 230 240 250
LIKKYDQMAI FHCLFWPSLT LLGGALIVGM VRLTQHLSLL CEKYSTVVRD
260 270
EVGGKVPYIE QHQFKLCIMR RSKGRAEKS
Length:279
Mass (Da):31,604
Last modified:March 7, 2006 - v2
Checksum:iEC5F0D5D3E040C4C
GO
Isoform 2 (identifier: Q9NPA1-2) [UniParc]FASTAAdd to basket
Also known as: 3a

The sequence of this isoform differs from the canonical sequence as follows:
     1-22: MDFSPSSELGFHFVAFILLTRH → MQPFSIPVQITLQGSRRRQG

Show »
Length:277
Mass (Da):31,351
Checksum:iEBF06FF8686F0655
GO
Isoform 3 (identifier: Q9NPA1-3) [UniParc]FASTAAdd to basket
Also known as: 3c

The sequence of this isoform differs from the canonical sequence as follows:
     1-22: MDFSPSSELGFHFVAFILLTRH → MFPLLYELTAVSPSPFPQ

Show »
Length:275
Mass (Da):31,089
Checksum:i9C7C5A523D37D5C2
GO
Isoform 4 (identifier: Q9NPA1-4) [UniParc]FASTAAdd to basket
Also known as: 3b

The sequence of this isoform differs from the canonical sequence as follows:
     1-22: Missing.
     23-23: R → M

Show »
Length:257
Mass (Da):29,045
Checksum:i0B5D59CB0551295D
GO
Isoform 5 (identifier: Q9NPA1-5) [UniParc]FASTAAdd to basket

The sequence of this isoform differs from the canonical sequence as follows:
     1-22: MDFSPSSELGFHFVAFILLTRH → MQPFSIPVQITLQGSRRRQG
     154-175: CFYTPKCHQDRNDLLNSALDIK → RDVTDCRVKEKQTLTVSDEHKQ
     176-279: Missing.

Note: No experimental confirmation available.
Show »
Length:173
Mass (Da):19,474
Checksum:i7EACEF7D7202F1B8
GO

Experimental Info

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Sequence conflicti24T → P in BAH14265 (PubMed:14702039).Curated1

Natural variant

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Natural variantiVAR_01817344D → G.Corresponds to variant rs1170672dbSNPEnsembl.1
Natural variantiVAR_01817453A → T.5 PublicationsCorresponds to variant rs7645550dbSNPEnsembl.1
Natural variantiVAR_01817575L → V.1 PublicationCorresponds to variant rs2276802dbSNPEnsembl.1
Natural variantiVAR_018176165N → S.2 PublicationsCorresponds to variant rs139527128dbSNPEnsembl.1
Natural variantiVAR_018177230M → T.1 PublicationCorresponds to variant rs145985409dbSNPEnsembl.1

Alternative sequence

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Alternative sequenceiVSP_0098271 – 22MDFSP…LLTRH → MQPFSIPVQITLQGSRRRQG in isoform 2 and isoform 5. 1 PublicationAdd BLAST22
Alternative sequenceiVSP_0098281 – 22MDFSP…LLTRH → MFPLLYELTAVSPSPFPQ in isoform 3. 1 PublicationAdd BLAST22
Alternative sequenceiVSP_0098291 – 22Missing in isoform 4. 2 PublicationsAdd BLAST22
Alternative sequenceiVSP_00983023R → M in isoform 4. 2 Publications1
Alternative sequenceiVSP_046090154 – 175CFYTP…ALDIK → RDVTDCRVKEKQTLTVSDEH KQ in isoform 5. 1 PublicationAdd BLAST22
Alternative sequenceiVSP_046091176 – 279Missing in isoform 5. 1 PublicationAdd BLAST104

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
AF139471 mRNA. Translation: AAD54771.1.
AF214561 mRNA. Translation: AAF36598.1.
AF204159 Genomic DNA. Translation: AAF97031.1.
AF204160 Genomic DNA. Translation: AAF97032.1.
AF204161 Genomic DNA. Translation: AAF97033.1.
AF204162 Genomic DNA. Translation: AAF97034.1.
AF160968 mRNA. Translation: AAF67811.1.
AF170916 mRNA. Translation: AAF89698.1.
AK304837 mRNA. Translation: BAH14265.1.
AC007823 Genomic DNA. No translation available.
AC076966 Genomic DNA. No translation available.
CH471052 Genomic DNA. Translation: EAW78418.1.
CH471052 Genomic DNA. Translation: EAW78421.1.
CCDSiCCDS3225.1. [Q9NPA1-2]
CCDS3226.1. [Q9NPA1-1]
CCDS43172.1. [Q9NPA1-4]
CCDS43173.1. [Q9NPA1-3]
CCDS54683.1. [Q9NPA1-5]
RefSeqiNP_001157149.1. NM_001163677.1. [Q9NPA1-5]
NP_055222.3. NM_014407.3. [Q9NPA1-1]
NP_741979.1. NM_171828.2. [Q9NPA1-2]
NP_741980.1. NM_171829.2. [Q9NPA1-4]
NP_741981.1. NM_171830.1. [Q9NPA1-3]
UniGeneiHs.591285.

Genome annotation databases

EnsembliENST00000314235; ENSP00000319370; ENSG00000171121. [Q9NPA1-1]
ENST00000349697; ENSP00000327866; ENSG00000171121. [Q9NPA1-2]
ENST00000392685; ENSP00000376451; ENSG00000171121. [Q9NPA1-3]
ENST00000392686; ENSP00000376452; ENSG00000171121. [Q9NPA1-4]
ENST00000485523; ENSP00000418536; ENSG00000171121. [Q9NPA1-4]
ENST00000497599; ENSP00000417091; ENSG00000171121. [Q9NPA1-5]
GeneIDi27094.
KEGGihsa:27094.
UCSCiuc003fjm.4. human. [Q9NPA1-1]

Keywords - Coding sequence diversityi

Alternative splicing, Polymorphism

Cross-referencesi

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
AF139471 mRNA. Translation: AAD54771.1.
AF214561 mRNA. Translation: AAF36598.1.
AF204159 Genomic DNA. Translation: AAF97031.1.
AF204160 Genomic DNA. Translation: AAF97032.1.
AF204161 Genomic DNA. Translation: AAF97033.1.
AF204162 Genomic DNA. Translation: AAF97034.1.
AF160968 mRNA. Translation: AAF67811.1.
AF170916 mRNA. Translation: AAF89698.1.
AK304837 mRNA. Translation: BAH14265.1.
AC007823 Genomic DNA. No translation available.
AC076966 Genomic DNA. No translation available.
CH471052 Genomic DNA. Translation: EAW78418.1.
CH471052 Genomic DNA. Translation: EAW78421.1.
CCDSiCCDS3225.1. [Q9NPA1-2]
CCDS3226.1. [Q9NPA1-1]
CCDS43172.1. [Q9NPA1-4]
CCDS43173.1. [Q9NPA1-3]
CCDS54683.1. [Q9NPA1-5]
RefSeqiNP_001157149.1. NM_001163677.1. [Q9NPA1-5]
NP_055222.3. NM_014407.3. [Q9NPA1-1]
NP_741979.1. NM_171828.2. [Q9NPA1-2]
NP_741980.1. NM_171829.2. [Q9NPA1-4]
NP_741981.1. NM_171830.1. [Q9NPA1-3]
UniGeneiHs.591285.

3D structure databases

ProteinModelPortaliQ9NPA1.
SMRiQ9NPA1.
ModBaseiSearch...
MobiDBiSearch...

Protein-protein interaction databases

STRINGi9606.ENSP00000319370.

Chemistry databases

DrugBankiDB01110. Miconazole.
DB00721. Procaine.

Protein family/group databases

TCDBi8.A.14.1.4. the ca(2+)-activated k(+) channel auxiliary subunit slowpoke-Beta (sloBeta) family.

Polymorphism and mutation databases

BioMutaiKCNMB3.
DMDMi90111824.

Proteomic databases

PaxDbiQ9NPA1.
PRIDEiQ9NPA1.

Protocols and materials databases

DNASUi27094.
Structural Biology KnowledgebaseSearch...

Genome annotation databases

EnsembliENST00000314235; ENSP00000319370; ENSG00000171121. [Q9NPA1-1]
ENST00000349697; ENSP00000327866; ENSG00000171121. [Q9NPA1-2]
ENST00000392685; ENSP00000376451; ENSG00000171121. [Q9NPA1-3]
ENST00000392686; ENSP00000376452; ENSG00000171121. [Q9NPA1-4]
ENST00000485523; ENSP00000418536; ENSG00000171121. [Q9NPA1-4]
ENST00000497599; ENSP00000417091; ENSG00000171121. [Q9NPA1-5]
GeneIDi27094.
KEGGihsa:27094.
UCSCiuc003fjm.4. human. [Q9NPA1-1]

Organism-specific databases

CTDi27094.
DisGeNETi27094.
GeneCardsiKCNMB3.
HGNCiHGNC:6287. KCNMB3.
HPAiHPA015665.
HPA019185.
MIMi605222. gene.
neXtProtiNX_Q9NPA1.
OpenTargetsiENSG00000171121.
PharmGKBiPA30067.
GenAtlasiSearch...

Phylogenomic databases

eggNOGiENOG410IF7H. Eukaryota.
ENOG410YQCT. LUCA.
GeneTreeiENSGT00390000015997.
HOGENOMiHOG000290180.
HOVERGENiHBG108059.
InParanoidiQ9NPA1.
KOiK04939.
OMAiKPFMLST.
OrthoDBiEOG091G0MVO.
PhylomeDBiQ9NPA1.
TreeFamiTF328589.

Enzyme and pathway databases

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

Miscellaneous databases

GeneWikiiKCNMB3.
GenomeRNAii27094.
PROiQ9NPA1.
SOURCEiSearch...

Gene expression databases

BgeeiENSG00000171121.
CleanExiHS_KCNMB2.
HS_KCNMB3.
ExpressionAtlasiQ9NPA1. baseline and differential.
GenevisibleiQ9NPA1. HS.

Family and domain databases

InterProiIPR003930. K_chnl_Ca-activ_BK_bsu.
[Graphical view]
PANTHERiPTHR10258. PTHR10258. 1 hit.
PfamiPF03185. CaKB. 1 hit.
[Graphical view]
ProtoNetiSearch...

Entry informationi

Entry nameiKCMB3_HUMAN
AccessioniPrimary (citable) accession number: Q9NPA1
Secondary accession number(s): B7Z9C9
, D3DNR2, E9PER5, Q9NPG7, Q9NRM9, Q9UHN3
Entry historyi
Integrated into UniProtKB/Swiss-Prot: April 13, 2004
Last sequence update: March 7, 2006
Last modified: November 2, 2016
This is version 130 of the entry and version 2 of the sequence. [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 3
    Human chromosome 3: 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

Similar proteinsi

Links to similar proteins from the UniProt Reference Clusters (UniRef) at 100%, 90% and 50% sequence identity:
100%UniRef100 combines identical sequences and sub-fragments with 11 or more residues from any organism into one UniRef entry.
90%UniRef90 is built by clustering UniRef100 sequences that have at least 90% sequence identity to, and 80% overlap with, the longest sequence (a.k.a seed sequence).
50%UniRef50 is built by clustering UniRef90 seed sequences that have at least 50% sequence identity to, and 80% overlap with, the longest sequence in the cluster.