O43525 (KCNQ3_HUMAN) Reviewed, UniProtKB/Swiss-Prot
Last modified
May 29, 2013.
Version 129.
History...
Names·Attributes·General annotation·Ontologies·Alt products·Sequence annotation·Sequences·References·Web links·Cross-refs·Entry info·DocumentsCustomize order
Names·Attributes·General annotation·Ontologies·Alt products·Sequence annotation·Sequences·References·Web links·Cross-refs·Entry info·DocumentsCustomize orderNames and origin
| Protein names | Recommended name: Potassium voltage-gated channel subfamily KQT member 3 Alternative name(s): KQT-like 3 Potassium channel subunit alpha KvLQT3 Voltage-gated potassium channel subunit Kv7.3 | ||
| Gene names |
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| Organism | Homo sapiens (Human) [Reference proteome] | ||
| Taxonomic identifier | 9606 [NCBI] | ||
| Taxonomic lineage | Eukaryota › Metazoa › Chordata › Craniata › Vertebrata › Euteleostomi › Mammalia › Eutheria › Euarchontoglires › Primates › Haplorrhini › Catarrhini › Hominidae › Homo![]() |
Protein attributes
| Sequence length | 872 AA. |
| Sequence status | Complete. |
| Protein existence | Evidence at protein level |
General annotation (Comments)
| Function | Probably important in the regulation of neuronal excitability. Associates with KCNQ2 or KCNQ5 to form a potassium channel with essentially identical properties to the channel underlying the native M-current, a slowly activating and deactivating potassium conductance which plays a critical role in determining the subthreshold electrical excitability of neurons as well as the responsiveness to synaptic inputs. |
| Subunit structure | Heteromultimer with KCNQ2 or KCNQ5. May associate with KCNE2. |
| Subcellular location | |
| Tissue specificity | Predominantly expressed in brain. |
| Domain | The segment S4 is probably the voltage-sensor and is characterized by a series of positively charged amino acids at every third position By similarity. |
| Involvement in disease | Seizures, benign familial neonatal 2 (BFNS2) [MIM:121201]: A disorder characterized by clusters of seizures occurring in the first days of life. Most patients have spontaneous remission by 12 months of age and show normal psychomotor development. The disorder is distinguished from benign familial infantile seizures by an earlier age at onset. |
| Miscellaneous | Mutagenesis experiments were carried out in Xenopus oocytes by coexpression of either KCNQ3(mut) and KCNQ2 at the ratio of 1:1, or of KCNQ3(mut), KCNQ3(wt) and KCNQ2 at the ratio of 1:1:2, to mimic the situation in a heterozygous patient with BFNC2 disease. |
| Sequence similarities | Belongs to the potassium channel family. KQT (TC 1.A.1.15) subfamily. Kv7.3/KCNQ3 sub-subfamily. [View classification] |
Ontologies
Alternative products
| This entry describes 2 isoforms produced by alternative splicing. [Align] [Select] | ||||||
| Isoform 1 (identifier: O43525-1) 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: O43525-2) The sequence of this isoform differs from the canonical sequence as follows: 1-9: MGLKARRAA → MKPAEHATM 10-129: Missing. | ||||||
| Note: No experimental confirmation available. |
Sequence annotation (Features)
| Feature key | Position(s) | Length | Description | Graphical view | Feature identifier | ||||
Molecule processing | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Chain | 1 – 872 | 872 | Potassium voltage-gated channel subfamily KQT member 3 | PRO_0000054034 | |||||
Regions | |||||||||
| Transmembrane | 122 – 142 | 21 | Helical; Name=Segment S1; Potential | ||||||
| Transmembrane | 153 – 173 | 21 | Helical; Name=Segment S2; Potential | ||||||
| Transmembrane | 197 – 217 | 21 | Helical; Name=Segment S3; Potential | ||||||
| Transmembrane | 226 – 247 | 22 | Helical; Voltage-sensor; Name=Segment S4; Potential | ||||||
| Transmembrane | 262 – 282 | 21 | Helical; Name=Segment S5; Potential | ||||||
| Intramembrane | 304 – 324 | 21 | Pore-forming; Name=Segment H5; Potential | ||||||
| Transmembrane | 331 – 351 | 21 | Helical; Name=Segment S6; Potential | ||||||
| Motif | 316 – 321 | 6 | Selectivity filter By similarity | ||||||
| Compositional bias | 13 – 24 | 12 | Poly-Gly | ||||||
Amino acid modifications | |||||||||
| Modified residue | 246 | 1 | Phosphothreonine Ref.15 | ||||||
| Modified residue | 598 | 1 | Phosphoserine By similarity | ||||||
Natural variations | |||||||||
| Alternative sequence | 1 – 9 | 9 | MGLKARRAA → MKPAEHATM in isoform 2. | VSP_044906 | |||||
| Alternative sequence | 10 – 129 | 120 | Missing in isoform 2. | VSP_044907 | |||||
| Natural variant | 305 | 1 | D → G in BFNS2; reduces the maximal heteromeric current by approx. 40% with no alteration in voltage dependence of activation or deactivation kinetics. Ref.17 | VAR_026994 | |||||
| Natural variant | 309 | 1 | W → R in BFNS2. Ref.16 | VAR_010935 | |||||
| Natural variant | 310 | 1 | G → V in BFNS2; about 50% reduction of wild-type heteromeric current; ratio of 1:1; or 20%; ratio of 1:1:2. Ref.1 Ref.5 Ref.17 | VAR_001546 | |||||
| Natural variant | 414 | 1 | E → G. Corresponds to variant rs2303995 [ dbSNP | Ensembl ]. | VAR_053859 | |||||
| Natural variant | 468 | 1 | N → S Has no statistically significant effect on the current or biophysical properties of the heteromeric channel. Ref.17 | VAR_026995 | |||||
Experimental info | |||||||||
| Mutagenesis | 246 | 1 | T → A: No effect on current or expression. Ref.15 | ||||||
| Mutagenesis | 246 | 1 | T → D: Abolishes currents without reducing channel protein expression. Ref.15 | ||||||
| Mutagenesis | 318 | 1 | G → S: >50% Reduction of wt heteromeric current; ratio of 1:1 and 1:1:2. Ref.1 | ||||||
| Sequence conflict | 233 | 1 | Q → L in BAG58996. Ref.3 | ||||||
Sequences
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References
| « Hide 'large scale' references | |
| [1] | "Moderate loss of function of cyclic-AMP-modulated KCNQ2/KCNQ3 K+ channels causes epilepsy." Schroeder B.C., Kubisch C., Stein V., Jentsch T.J. Nature 396:687-690(1998) [PubMed] [Europe PMC] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA], CHARACTERIZATION OF VARIANT BFNS2 VAL-310, MUTAGENESIS OF GLY-318. Tissue: Brain. |
| [2] | "Functional expression of two KvLQT1-related potassium channels responsible for an inherited idiopathic epilepsy." Yang W.-P., Levesque P.C., Little W.A., Conder M.L., Ramakrishnan P., Neubauer M.G., Blanar M.A. J. Biol. Chem. 273:19419-19423(1998) [PubMed] [Europe PMC] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA] (ISOFORM 1), CHARACTERIZATION. Tissue: Brain and Fetal brain. |
| [3] | "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. Sugano S.Nat. Genet. 36:40-45(2004) [PubMed] [Europe PMC] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA] (ISOFORM 2). Tissue: Thalamus. |
| [4] | "DNA sequence and analysis of human chromosome 8." Nusbaum C., Mikkelsen T.S., Zody M.C., Asakawa S., Taudien S., Garber M., Kodira C.D., Schueler M.G., Shimizu A., Whittaker C.A., Chang J.L., Cuomo C.A., Dewar K., FitzGerald M.G., Yang X., Allen N.R., Anderson S., Asakawa T. Lander E.S.Nature 439:331-335(2006) [PubMed] [Europe PMC] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA]. |
| [5] | "A pore mutation in a novel KQT-like potassium channel gene in an idiopathic epilepsy family." Charlier C., Singh N.A., Ryan S.G., Lewis T.B., Reus B.E., Leach R.J., Leppert M. Nat. Genet. 18:53-55(1998) [PubMed] [Europe PMC] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA] OF 48-872 (ISOFORM 1), VARIANT BFNS2 VAL-310. Tissue: Brain. |
| [6] | "Two types of K(+) channel subunit, Erg1 and KCNQ2/3, contribute to the M-like current in a mammalian neuronal cell." Selyanko A.A., Hadley J.K., Wood I.C., Abogadie F.C., Delmas P., Buckley N.J., London B., Brown D.A. J. Neurosci. 19:7742-7756(1999) [PubMed] [Europe PMC] [Abstract] Cited for: INVOLVEMENT IN M-LIKE CURRENT. |
| [7] | "M-type KCNQ2-KCNQ3 potassium channels are modulated by the KCNE2 subunit." Tinel N., Diochot S., Lauritzen I., Barhanin J., Lazdunski M., Borsotto M. FEBS Lett. 480:137-141(2000) [PubMed] [Europe PMC] [Abstract] Cited for: ASSOCIATION WITH KCNE2. |
| [8] | "Surface expression and single channel properties of KCNQ2/KCNQ3, M-type K+ channels involved in epilepsy." Schwake M., Pusch M., Kharkovets T., Jentsch T.J. J. Biol. Chem. 275:13343-13348(2000) [PubMed] [Europe PMC] [Abstract] Cited for: SURFACE EXPRESSION OF HETEROMERS. |
| [9] | "Reconstitution of muscarinic modulation of the KCNQ2/KCNQ3 K(+) channels that underlie the neuronal M current." Shapiro M.S., Roche J.P., Kaftan E.J., Cruzblanca H., Mackie K., Hille B. J. Neurosci. 20:1710-1721(2000) [PubMed] [Europe PMC] [Abstract] Cited for: INHIBITION BY M1 MUSCARINIC RECEPTORS. |
| [10] | "Inhibition of KCNQ1-4 potassium channels expressed in mammalian cells via M1 muscarinic acetylcholine receptors." Selyanko A.A., Hadley J.K., Wood I.C., Abogadie F.C., Jentsch T.J., Brown D.A. J. Physiol. (Lond.) 522:349-355(2000) [PubMed] [Europe PMC] [Abstract] Cited for: INHIBITION BY M1 MUSCARINIC RECEPTORS. |
| [11] | "Modulation of KCNQ2/3 potassium channels by the novel anticonvulsant retigabine." Main M.J., Cryan J.E., Dupere J.R., Cox B., Clare J.J., Burbidge S.A. Mol. Pharmacol. 58:253-262(2000) [PubMed] [Europe PMC] [Abstract] Cited for: ACTIVATION BY RETICABINE. |
| [12] | "Retigabine, a novel anti-convulsant, enhances activation of KCNQ2/Q3 potassium channels." Wickenden A.D., Yu W., Zou A., Jegla T., Wagoner P.K. Mol. Pharmacol. 58:591-600(2000) [PubMed] [Europe PMC] [Abstract] Cited for: ACTIVATION BY RETICABINE. |
| [13] | "The novel anticonvulsant retigabine activates M-currents in Chinese hamster ovary-cells transfected with human KCNQ2/3 subunits." Rundfeldt C., Netzer R. Neurosci. Lett. 282:73-76(2000) [PubMed] [Europe PMC] [Abstract] Cited for: ACTIVATION BY RETICABINE. |
| [14] | "Characterization of KCNQ5/Q3 potassium channels expressed in mammalian cells." Wickenden A.D., Zou A., Wagoner P.K., Jegla T. Br. J. Pharmacol. 132:381-384(2001) [PubMed] [Europe PMC] [Abstract] Cited for: CHARACTERIZATION, ACTIVATION BY RETICABINE. |
| [15] | "Identification by mass spectrometry and functional characterization of two phosphorylation sites of KCNQ2/KCNQ3 channels." Surti T.S., Huang L., Jan Y.N., Jan L.Y., Cooper E.C. Proc. Natl. Acad. Sci. U.S.A. 102:17828-17833(2005) [PubMed] [Europe PMC] [Abstract] Cited for: PHOSPHORYLATION AT THR-246, MUTAGENESIS OF THR-246. |
| [16] | "A novel mutation of KCNQ3 (c.925T-->C) in a Japanese family with benign familial neonatal convulsions." Hirose S., Zenri F., Akiyoshi H., Fukuma G., Iwata H., Inoue T., Yonetani M., Tsutsumi M., Muranaka H., Kurokawa T., Hanai T., Wada K., Kaneko S., Mitsudome A. Ann. Neurol. 47:822-826(2000) [PubMed] [Europe PMC] [Abstract] Cited for: VARIANT BFNS2 ARG-309. |
| [17] | "KCNQ2 and KCNQ3 potassium channel genes in benign familial neonatal convulsions: expansion of the functional and mutation spectrum." The BFNC physician consortium Singh N.A., Westenskow P., Charlier C., Pappas C., Leslie J., Dillon J., Anderson V.E., Sanguinetti M.C., Leppert M.F. Brain 126:2726-2737(2003) [PubMed] [Europe PMC] [Abstract] Cited for: VARIANTS BFNS2 GLY-305 AND VAL-310, CHARACTERIZATION OF VARIANT BFNS2 GLY-305, VARIANT SER-468, CHARACTERIZATION OF VARIANT SER-468. |
| + | Additional computationally mapped references. |
Web resources
Cross-references
Sequence databases | |
|---|---|
| EMBL GenBank DDBJ | AF071491 AF071490 Genomic DNA. Translation: AAC96101.1.AK296293 mRNA. Translation: BAG58996.1. AC018540 Genomic DNA. No translation available. AC123776 Genomic DNA. No translation available. AC131042 Genomic DNA. No translation available. AC136373 Genomic DNA. No translation available. AF033347 mRNA. Translation: AAB97314.1. |
| IPI | IPI00012857. IPI00976856. |
| RefSeq | NP_001191753.1. NM_001204824.1. NP_004510.1. NM_004519.3. |
| UniGene | Hs.374023. |
3D structure databases | |
| ProteinModelPortal | O43525. |
| ModBase | Search... |
Protein-protein interaction databases | |
| STRING | 9606.ENSP00000373648. |
Protein family/group databases | |
| TCDB | 1.A.1.15.3. voltage-gated ion channel (VIC) superfamily. |
PTM databases | |
| PhosphoSite | O43525. |
Proteomic databases | |
| PaxDb | O43525. |
| PRIDE | O43525. |
Protocols and materials databases | |
| DNASU | 3786. |
| StructuralBiologyKnowledgebase | Search... |
Genome annotation databases | |
| Ensembl | ENST00000388996; ENSP00000373648; ENSG00000184156. ENST00000521134; ENSP00000429799; ENSG00000184156. |
| GeneID | 3786. |
| KEGG | hsa:3786. |
| UCSC | uc003yti.3. human. uc003ytj.3. human. |
Organism-specific databases | |
| CTD | 3786. |
| GeneCards | GC08M133210. |
| HGNC | HGNC:6297. KCNQ3. |
| HPA | HPA035212. |
| MIM | 121201. phenotype. 602232. gene. |
| neXtProt | NX_O43525. |
| Orphanet | 1949. Benign familial neonatal seizures. 307. Juvenile myoclonic epilepsy. |
| PharmGKB | PA30075. |
| GenAtlas | Search... |
Phylogenomic databases | |
| eggNOG | COG1226. |
| HOGENOM | HOG000220839. |
| HOVERGEN | HBG059014. |
| InParanoid | O43525. |
| KO | K04928. |
| OMA | TRIDMIF. |
| OrthoDB | EOG4V9TPZ. |
Enzyme and pathway databases | |
| Reactome | REACT_111045. Developmental Biology. REACT_13685. Neuronal System. |
Gene expression databases | |
| ArrayExpress | O43525. |
| Bgee | O43525. |
| CleanEx | HS_KCNQ3. |
| Genevestigator | O43525. |
| GermOnline | ENSG00000184156. Homo sapiens. |
Family and domain databases | |
| InterPro | IPR020969. Ankyrin-G_BS. IPR005821. Ion_trans_dom. IPR003091. K_chnl. IPR003937. K_chnl_volt-dep_KCNQ. IPR003948. K_chnl_volt-dep_KCNQ3. IPR013821. K_chnl_volt-dep_KCNQ_C. [Graphical view] |
| PANTHER | PTHR11537. PTHR11537. 1 hit. PTHR11537:SF5. PTHR11537:SF5. 1 hit. |
| Pfam | PF00520. Ion_trans. 1 hit. PF03520. KCNQ_channel. 1 hit. PF11956. KCNQC3-Ank-G_bd. 1 hit. [Graphical view] |
| PRINTS | PR00169. KCHANNEL. PR01462. KCNQ3CHANNEL. PR01459. KCNQCHANNEL. |
| ProtoNet | Search... |
Other | |
| BindingDB | O43525. |
| ChEMBL | CHEMBL2684. |
| ChiTaRS | KCNQ3. human. |
| GenomeRNAi | 3786. |
| NextBio | 14871. |
| SOURCE | Search... |
Entry information
| Entry name | KCNQ3_HUMAN | ||||||||
| Accession | Primary (citable) accession number: O43525 Secondary accession number(s): B4DJY4, E7EQ89 | ||||||||
| Entry history |
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| 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. | ||||||||
Relevant documents
| Human chromosome 8 Human chromosome 8: entries, gene names and cross-references to MIM |
| Human entries with polymorphisms or disease mutations List of human entries with polymorphisms or disease mutations |
| Human polymorphisms and disease mutations Index of human polymorphisms and disease mutations |
| MIM cross-references Online Mendelian Inheritance in Man (MIM) cross-references in UniProtKB/Swiss-Prot |
| SIMILARITY comments Index of protein domains and families |

Clusters with
