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Protein

Potassium voltage-gated channel subfamily KQT member 3

Gene

Kcnq3

Organism
Rattus norvegicus (Rat)
Status
Reviewed-Annotation score: Annotation score: 5 out of 5-Experimental evidence at protein leveli

Functioni

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. Therefore, it is important in the regulation of neuronal excitability.1 Publication

GO - Molecular functioni

  • calmodulin binding Source: RGD
  • ion channel binding Source: RGD
  • protein kinase binding Source: RGD
  • ubiquitin protein ligase binding Source: RGD
  • voltage-gated potassium channel activity Source: GO_Central

GO - Biological processi

  • cellular response to ammonium ion Source: RGD
  • ganglion development Source: RGD
  • ion transmembrane transport Source: RGD
  • oligodendrocyte development Source: RGD
  • potassium ion transmembrane transport Source: GO_Central

Keywordsi

Molecular functionIon channel, Potassium channel, Voltage-gated channel
Biological processIon transport, Potassium transport, Transport
LigandPotassium

Names & Taxonomyi

Protein namesi
Recommended name:
Potassium voltage-gated channel subfamily KQT member 3Curated
Alternative name(s):
KQT-like 3
Potassium channel subunit alpha KvLQT3
Voltage-gated potassium channel subunit Kv7.3
Gene namesi
Name:Kcnq3Imported
OrganismiRattus norvegicus (Rat)
Taxonomic identifieri10116 [NCBI]
Taxonomic lineageiEukaryotaMetazoaChordataCraniataVertebrataEuteleostomiMammaliaEutheriaEuarchontogliresGliresRodentiaMyomorphaMuroideaMuridaeMurinaeRattus
Proteomesi
  • UP000002494 Componenti: Unplaced

Organism-specific databases

RGDi69222. Kcnq3.

Subcellular locationi

Topology

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Topological domaini1 – 122CytoplasmicSequence analysisAdd BLAST122
Transmembranei123 – 143Helical; Name=Segment S1Sequence analysisAdd BLAST21
Topological domaini144 – 153ExtracellularCurated10
Transmembranei154 – 174Helical; Name=Segment S2Sequence analysisAdd BLAST21
Topological domaini175 – 197CytoplasmicCuratedAdd BLAST23
Transmembranei198 – 218Helical; Name=Segment S3Sequence analysisAdd BLAST21
Topological domaini219 – 226ExtracellularCurated8
Transmembranei227 – 248Helical; Voltage-sensor; Name=Segment S4Sequence analysisAdd BLAST22
Topological domaini249 – 262CytoplasmicCuratedAdd BLAST14
Transmembranei263 – 283Helical; Name=Segment S5Sequence analysisAdd BLAST21
Topological domaini284 – 304ExtracellularCuratedAdd BLAST21
Intramembranei305 – 325Pore-forming; Name=Segment H5Sequence analysisAdd BLAST21
Topological domaini326 – 331ExtracellularCurated6
Transmembranei332 – 352Helical; Name=Segment S6Sequence analysisAdd BLAST21
Topological domaini353 – 873CytoplasmicCuratedAdd BLAST521

GO - Cellular componenti

  • axon initial segment Source: RGD
  • cell surface Source: RGD
  • dendrite Source: RGD
  • integral component of membrane Source: GO_Central
  • membrane raft Source: RGD
  • neuronal cell body Source: RGD
  • neuron projection Source: RGD
  • somatodendritic compartment Source: RGD
  • voltage-gated potassium channel complex Source: InterPro

Keywords - Cellular componenti

Cell membrane, Membrane

Pathology & Biotechi

Chemistry databases

ChEMBLiCHEMBL5531.
GuidetoPHARMACOLOGYi562.

PTM / Processingi

Molecule processing

Feature keyPosition(s)DescriptionActionsGraphical viewLength
ChainiPRO_00000540361 – 873Potassium voltage-gated channel subfamily KQT member 3Add BLAST873

Amino acid modifications

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Modified residuei82PhosphothreonineCombined sources1

Keywords - PTMi

Phosphoprotein

Proteomic databases

PaxDbiO88944.
PRIDEiO88944.

PTM databases

iPTMnetiO88944.
PhosphoSitePlusiO88944.

Expressioni

Tissue specificityi

Expressed in brain and sympathetic ganglia. In brain, expressed in cortex, hippocampus and at much lower levels in cerebellum. In sympathetic ganglia, expressed at approximately equal levels in both superior cervical ganglia and prevertebral ganglia.

Gene expression databases

GenevisibleiO88944. RN.

Interactioni

Subunit structurei

Heterotetramer with KCNQ2; form the heterotetrameric M potassium channel. Interacts with calmodulin; the interaction is calcium-independent, constitutive and participates to the proper assembly of a functional heterotetrameric M channel. Heteromultimer with KCNQ5. May associate with KCNE2.By similarity

GO - Molecular functioni

  • calmodulin binding Source: RGD
  • ion channel binding Source: RGD
  • protein kinase binding Source: RGD
  • ubiquitin protein ligase binding Source: RGD

Protein-protein interaction databases

STRINGi10116.ENSRNOP00000065354.

Structurei

3D structure databases

ProteinModelPortaliO88944.
ModBaseiSearch...
MobiDBiSearch...

Family & Domainsi

Region

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Regioni357 – 538Mediates interaction with calmodulinBy similarityAdd BLAST182

Motif

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Motifi317 – 322Selectivity filterBy similarity6

Compositional bias

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Compositional biasi13 – 25Poly-GlyAdd BLAST13

Domaini

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

Sequence similaritiesi

Keywords - Domaini

Transmembrane, Transmembrane helix

Phylogenomic databases

eggNOGiKOG1419. Eukaryota.
COG1226. LUCA.
HOGENOMiHOG000220839.
HOVERGENiHBG059014.
InParanoidiO88944.
OrthoDBiEOG091G02ZT.
PhylomeDBiO88944.

Family and domain databases

InterProiView protein in InterPro
IPR020969. Ankyrin-G_BS.
IPR005821. Ion_trans_dom.
IPR003937. K_chnl_volt-dep_KCNQ.
IPR003948. K_chnl_volt-dep_KCNQ3.
IPR013821. K_chnl_volt-dep_KCNQ_C.
IPR028325. VG_K_chnl.
PANTHERiPTHR11537. PTHR11537. 1 hit.
PTHR11537:SF174. PTHR11537:SF174. 1 hit.
PfamiView protein in Pfam
PF00520. Ion_trans. 1 hit.
PF03520. KCNQ_channel. 1 hit.
PF11956. KCNQC3-Ank-G_bd. 1 hit.
PRINTSiPR00169. KCHANNEL.
PR01462. KCNQ3CHANNEL.
PR01459. KCNQCHANNEL.

Sequences (2)i

Sequence statusi: Complete.

This entry describes 2 isoformsi produced by alternative splicing. AlignAdd to basket

Isoform 1 (identifier: O88944-1) [UniParc]FASTAAdd to basket

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
MGLKARRAAG AAGGGGGEGG GGGGGAANPA GGDSAVAGDE ERKVGLAPGD
60 70 80 90 100
VEQVTLALGT GADKDGTLLL EGGGREEGQR RTPQGIGLLA KTPLSRPVKR
110 120 130 140 150
NNAKYRRIQT LIYDALERPR GWALLYHALV FLIVLGCLIL AVLTTFKEYE
160 170 180 190 200
TVSGDWLLLL ETFAIFIFGA EFALRIWAAG CCCRYKGWRG RLKFARKPLC
210 220 230 240 250
MLDIFVLIAS VPVVAVGNQG NVLATSLRSL RFLQILRMLR MDRRGGTWKL
260 270 280 290 300
LGSAICAHSK ELITAWYIGF LTLILSSFLV YLVEKDVPEM DAQGEEMKEE
310 320 330 340 350
FETYADALWW GLITLATIGY GDKTPKTWEG RLIAATFSLI GVSFFALPAG
360 370 380 390 400
ILGSGLALKV QEQHRQKHFE KRRKPAAELI QAAWRYYATN PNRLDLVATW
410 420 430 440 450
RFYESVVSFP FFRKEQLEAA ASQKLGLLDR VRLSNPRGSN TKGKLFTPLN
460 470 480 490 500
VDAIEESPSK EPKPVGLNNK ERFRTAFRMK AYAFWQSSED AGTGDPMTED
510 520 530 540 550
RGYGNDFLIE DMIPTLKAAI RAVRILQFRL YKKKFKETLR PYDVKDVIEQ
560 570 580 590 600
YSAGHLDMLS RIKYLQTRID MIFTPGPPST PKHKKSQKGS AFTYPSQQSP
610 620 630 640 650
RNEPYVARAA TSETEDQSMM GKFVKVERQV HDMGKKLDFL VDMHMQHMER
660 670 680 690 700
LQVHVTEYYP TKGASSPAEG EKKEDNRYSD LKTIICNYSE SGPPDPPYSF
710 720 730 740 750
HQVPIDRVGP YGFFAHDPVK LTRGGPSSTK AQANLPSSGS TYAERPTVLP
760 770 780 790 800
ILTLLDSCVS YHSQTELQGP YSDHISPRQR RSITRDSDTP LSLMSVNHEE
810 820 830 840 850
LERSPSGFSI SQDRDDYVFG PSGGSSWMRE KRYLAEGETD TDTDPFTPSG
860 870
SMPMSSTGDG ISDSIWTPSN KPT
Length:873
Mass (Da):96,898
Last modified:December 19, 2001 - v2
Checksum:iD77AF88088051E15
GO
Isoform 2 (identifier: O88944-2) [UniParc]FASTAAdd to basket

The sequence of this isoform differs from the canonical sequence as follows:
     1-83: MGLKARRAAG...GREEGQRRTP → MALEFPGLQP...GGEADGAQGS

Note: No experimental confirmation available.
Show »
Length:835
Mass (Da):93,601
Checksum:i3B532712B4C4E773
GO

Experimental Info

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Sequence conflicti654H → R in AAC79846 (PubMed:9836639).Curated1

Alternative sequence

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Alternative sequenceiVSP_0010121 – 83MGLKA…QRRTP → MALEFPGLQPPPPPRPRTPS APSSRSSSGEGEAPSGGEAD GAQGS in isoform 2. 1 PublicationAdd BLAST83

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
AF087454 mRNA. Translation: AAC36723.2.
AF091247 mRNA. Translation: AAC79846.1.
UniGeneiRn.205060.

Genome annotation databases

UCSCiRGD:69222. rat. [O88944-1]

Keywords - Coding sequence diversityi

Alternative splicing

Similar proteinsi

Entry informationi

Entry nameiKCNQ3_RAT
AccessioniPrimary (citable) accession number: O88944
Secondary accession number(s): Q9Z240
Entry historyiIntegrated into UniProtKB/Swiss-Prot: June 1, 2001
Last sequence update: December 19, 2001
Last modified: August 30, 2017
This is version 139 of the entry and version 2 of the sequence. See complete history.
Entry statusiReviewed (UniProtKB/Swiss-Prot)
Annotation programChordata Protein Annotation Program

Miscellaneousi

Keywords - Technical termi

Complete proteome, Reference proteome

Documents

  1. SIMILARITY comments
    Index of protein domains and families