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Protein

Potassium voltage-gated channel subfamily B member 2

Gene

Kcnb2

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

Functioni

Voltage-gated potassium channel that mediates transmembrane potassium transport in excitable membranes, primarily in the brain and smooth muscle cells (PubMed:1550672). Channels open or close in response to the voltage difference across the membrane, letting potassium ions pass in accordance with their electrochemical gradient. Homotetrameric channels mediate a delayed-rectifier voltage-dependent outward potassium current that display rapid activation and slow inactivation in response to membrane depolarization (PubMed:1550672). Can form functional homotetrameric and heterotetrameric channels that contain variable proportions of KCNB1; channel properties depend on the type of alpha subunits that are part of the channel (PubMed:20202934). Can also form functional heterotetrameric channels with other alpha subunits that are non-conducting when expressed alone, such as KCNS1 and KCNS2, creating a functionally diverse range of channel complexes (PubMed:9305895). In vivo, membranes probably contain a mixture of heteromeric potassium channel complexes, making it difficult to assign currents observed in intact tissues to any particular potassium channel family member. Contributes to the delayed-rectifier voltage-gated potassium current in cortical pyramidal neurons and smooth muscle cells (PubMed:1550672, PubMed:20202934).By similarity3 Publications

Enzyme regulationi

Inhibited by quinine at micromolar levels (By similarity). Modestly sensitive to millimolar levels of tetraethylammonium (TEA) (PubMed:1550672). Modestly sensitive to millimolar levels of 4-aminopyridine (4-AP).By similarity1 Publication1 Publication

Kineticsi

Homotetrameric channels expressed in xenopus oocytes or in mammalian non-neuronal cells display delayed-rectifier voltage-dependent potassium currents which are activated during membrane depolarization, i.e within a risetime of about 20 msec (PubMed:1550672). After that, inactivate very slowly (PubMed:1550672). Their activation requires low threshold potentials of about -20 to -30 mV, with a midpoint activation at about 10 mV. For inactivation, the voltage at half-maximal amplitude is about -30 mV. Channels have an unitary conductance of about 14 pS. The voltage-dependence of activation and inactivation and other channel characteristics vary depending on the experimental conditions, the expression system and post-translational modifications.1 Publication

Manual assertion inferred by curator fromi

1 Publication

      GO - Molecular functioni

      • delayed rectifier potassium channel activity Source: UniProtKB
      • ion channel binding Source: UniProtKB
      • protein heterodimerization activity Source: UniProtKB

      GO - Biological processi

      • potassium ion transmembrane transport Source: UniProtKB
      • potassium ion transport Source: UniProtKB
      • protein homooligomerization Source: InterPro
      • protein targeting to plasma membrane Source: UniProtKB
      Complete GO annotation...

      Keywords - Molecular functioni

      Ion channel, Potassium channel, Voltage-gated channel

      Keywords - Biological processi

      Ion transport, Potassium transport, Transport

      Keywords - Ligandi

      Potassium

      Names & Taxonomyi

      Protein namesi
      Recommended name:
      Potassium voltage-gated channel subfamily B member 2Imported
      Alternative name(s):
      CDRK1 Publication
      Voltage-gated potassium channel subunit Kv2.2
      Gene namesi
      Name:Kcnb2Imported
      OrganismiRattus norvegicus (Rat)
      Taxonomic identifieri10116 [NCBI]
      Taxonomic lineageiEukaryotaMetazoaChordataCraniataVertebrataEuteleostomiMammaliaEutheriaEuarchontogliresGliresRodentiaSciurognathiMuroideaMuridaeMurinaeRattus
      Proteomesi
      • UP000002494 Componenti: Unplaced

      Organism-specific databases

      RGDi621349. Kcnb2.

      Subcellular locationi

      Topology

      Feature keyPosition(s)DescriptionActionsGraphical viewLength
      Topological domaini1 – 190CytoplasmicBy similarityAdd BLAST190
      Transmembranei191 – 212Helical; Name=Segment S1By similarityAdd BLAST22
      Topological domaini213 – 232ExtracellularBy similarityAdd BLAST20
      Transmembranei233 – 254Helical; Name=Segment S2By similarityAdd BLAST22
      Topological domaini255 – 265CytoplasmicBy similarityAdd BLAST11
      Transmembranei266 – 284Helical; Name=Segment S3By similarityAdd BLAST19
      Topological domaini285 – 296ExtracellularBy similarityAdd BLAST12
      Transmembranei297 – 317Helical; Voltage-sensor; Name=Segment S4By similarityAdd BLAST21
      Topological domaini318 – 332CytoplasmicBy similarityAdd BLAST15
      Transmembranei333 – 355Helical; Name=Segment S5By similarityAdd BLAST23
      Topological domaini356 – 368ExtracellularBy similarityAdd BLAST13
      Intramembranei369 – 380Helical; Name=Pore helixBy similarityAdd BLAST12
      Intramembranei381 – 388By similarity8
      Topological domaini389 – 395ExtracellularBy similarity7
      Transmembranei396 – 424Helical; Name=Segment S6By similarityAdd BLAST29
      Topological domaini425 – 907CytoplasmicBy similarityAdd BLAST483

      GO - Cellular componenti

      • dendrite Source: UniProtKB
      • intracellular Source: GOC
      • neuronal cell body Source: RGD
      • neuronal cell body membrane Source: UniProtKB
      • perikaryon Source: UniProtKB-SubCell
      • plasma membrane Source: UniProtKB
      • voltage-gated potassium channel complex Source: UniProtKB
      Complete GO annotation...

      Keywords - Cellular componenti

      Cell membrane, Cell projection, Membrane

      Pathology & Biotechi

      Chemistry databases

      GuidetoPHARMACOLOGYi547.

      PTM / Processingi

      Molecule processing

      Feature keyPosition(s)DescriptionActionsGraphical viewLength
      ChainiPRO_00000540501 – 907Potassium voltage-gated channel subfamily B member 2Add BLAST907

      Amino acid modifications

      Feature keyPosition(s)DescriptionActionsGraphical viewLength
      Glycosylationi287N-linked (GlcNAc...)Sequence analysis1
      Modified residuei448PhosphoserineCombined sources1

      Post-translational modificationi

      Phosphorylated (PubMed:20202934).1 Publication

      Keywords - PTMi

      Glycoprotein, Phosphoprotein

      Proteomic databases

      PaxDbiQ63099.
      PRIDEiQ63099.

      PTM databases

      iPTMnetiQ63099.
      PhosphoSitePlusiQ63099.

      Expressioni

      Tissue specificityi

      Expressed in pyramidal neurons of the cerebral cortex (at protein level) (PubMed:20202934). In the brain, the greatest density occurs in the olfactory bulb, followed by the cerebral cortex, hippocampus, and cerebellum. In peripheral tissues it is most prominent in whole tongue epithelium and circumvallate papillae (PubMed:1550672).2 Publications

      Interactioni

      Subunit structurei

      Homotetramer or heterotetramer with KCNB1 (PubMed:20202934). Heterotetramer with KCNS1 and KCNS2 (PubMed:9305895).By similarity2 Publications

      GO - Molecular functioni

      • ion channel binding Source: UniProtKB
      • protein heterodimerization activity Source: UniProtKB

      Protein-protein interaction databases

      STRINGi10116.ENSRNOP00000050431.

      Structurei

      3D structure databases

      ProteinModelPortaliQ63099.
      ModBaseiSearch...
      MobiDBiSearch...

      Family & Domainsi

      Motif

      Feature keyPosition(s)DescriptionActionsGraphical viewLength
      Motifi381 – 386Selectivity filterBy similarity6

      Domaini

      The transmembrane segment S4 functions as voltage-sensor and is characterized by a series of positively charged amino acids at every third position. Channel opening and closing is effected by a conformation change that affects the position and orientation of the voltage-sensor paddle formed by S3 and S4 within the membrane. A transmembrane electric field that is positive inside would push the positively charged S4 segment outwards, thereby opening the pore, while a field that is negative inside would pull the S4 segment inwards and close the pore. Changes in the position and orientation of S4 are then transmitted to the activation gate formed by the inner helix bundle via the S4-S5 linker region.By similarity

      Sequence similaritiesi

      Keywords - Domaini

      Transmembrane, Transmembrane helix

      Phylogenomic databases

      eggNOGiKOG3713. Eukaryota.
      COG1226. LUCA.
      HOGENOMiHOG000113206.
      HOVERGENiHBG052225.
      InParanoidiQ63099.
      PhylomeDBiQ63099.

      Family and domain databases

      InterProiIPR000210. BTB/POZ_dom.
      IPR005821. Ion_trans_dom.
      IPR003968. K_chnl_volt-dep_Kv.
      IPR003973. K_chnl_volt-dep_Kv2.
      IPR005826. K_chnl_volt-dep_Kv2.2.
      IPR011333. SKP1/BTB/POZ.
      IPR003131. T1-type_BTB.
      IPR028325. VG_K_chnl.
      [Graphical view]
      PANTHERiPTHR11537. PTHR11537. 1 hit.
      PfamiPF02214. BTB_2. 1 hit.
      PF00520. Ion_trans. 1 hit.
      PF03521. Kv2channel. 1 hit.
      [Graphical view]
      PRINTSiPR00169. KCHANNEL.
      PR01515. KV22CHANNEL.
      PR01491. KVCHANNEL.
      PR01495. SHABCHANNEL.
      SMARTiSM00225. BTB. 1 hit.
      [Graphical view]
      SUPFAMiSSF54695. SSF54695. 1 hit.

      Sequencei

      Sequence statusi: Complete.

      Q63099-1 [UniParc]FASTAAdd to basket

      « Hide

              10         20         30         40         50
      MAEKAPPGLN RKTSRSTLSL PPEPVDIIRS KTCSRRVKIN VGGLNHEVLW
      60 70 80 90 100
      RTLDRLPRTR LGKLRDCNTH ESLLEVCDDY NLNENEYFFD RHPGAFTSIL
      110 120 130 140 150
      NFYRTGKLHM MEEMCALSFG QELDYWGIDE IYLESCCQAR YHQKKEQMNE
      160 170 180 190 200
      ELRREAETMR DGEGEEFDNT CCPEKRKKLW DLLEKPNSSV AAKILAIVSI
      210 220 230 240 250
      LFIVLSTIAL SLNTLPELQE NDEFGQPSDN RKLAHVEAVC IAWFTMEYLL
      260 270 280 290 300
      RFLSSPNKWK FFKGPLNVID LLAILPYYVT IFLTESNKSV LQFQNVRRVV
      310 320 330 340 350
      QIFRIMRILR ILKLARHSTG LQSLGFTLRR SYNELGLLIL FLAMGIMIFS
      360 370 380 390 400
      SLVFFAEKDE DATKFTSIPA SFWWATITMT TVGYGDIYPK TLLGKIVGGL
      410 420 430 440 450
      CCIAGVLVIA LPIPIIVNNF SEFYKEQKRQ EKAIKRREAL ERAKRNGSIV
      460 470 480 490 500
      SMNLKDAFAR SMELIDVAVE KAGESANIKD SVDDNHLSPS RWKWARKALS
      510 520 530 540 550
      ETSSNKSYEN KYQEVSQKDS HEQLNNTSSS SPQHLSAQKL EMLYNEITKT
      560 570 580 590 600
      QTHSHPNPDC QEQPERPSAY EEEIEMEEVV CPQEQLAVAQ TEVIVDMKST
      610 620 630 640 650
      SSIDSFTSCA TDFTETERSP LPPPSASHLQ MKFPTDLPGM DEHQRVRAPP
      660 670 680 690 700
      FLTLSRDKGP AAREAALDYA PIDITVNLDA GASHGPLQPD SASDSPKSSL
      710 720 730 740 750
      KGSNPLKSRS LKVNFQENRG SAPQTPPSTA RPLPVTTADF PLTTPQHMST
      760 770 780 790 800
      ILLEESPPPG TETLPGADVS AHCQGPSKGL SPRVPKQKLF PFSSRERRSF
      810 820 830 840 850
      TEIDTGEDED FLDLQRPRPD KQADPSPNCL ADKPGEARDP LREEGCVGSS
      860 870 880 890 900
      SPQNTDHNCR QDIYQAVGEV KKDSSQEGYK MENHLFAPEI HSNPGDTGYC

      PTRETSM
      Length:907
      Mass (Da):102,096
      Last modified:October 25, 2002 - v2
      Checksum:iB242D9A6753A1295
      GO

      Sequence cautioni

      The sequence AAA40905 differs from that shown. Reason: Frameshift at position 755.Curated

      Sequence databases

      Select the link destinations:
      EMBLi
      GenBanki
      DDBJi
      Links Updated
      M77482 mRNA. Translation: AAA40905.1. Frameshift.
      PIRiJH0595.
      UniGeneiRn.32101.

      Genome annotation databases

      UCSCiRGD:621349. rat.

      Cross-referencesi

      Sequence databases

      Select the link destinations:
      EMBLi
      GenBanki
      DDBJi
      Links Updated
      M77482 mRNA. Translation: AAA40905.1. Frameshift.
      PIRiJH0595.
      UniGeneiRn.32101.

      3D structure databases

      ProteinModelPortaliQ63099.
      ModBaseiSearch...
      MobiDBiSearch...

      Protein-protein interaction databases

      STRINGi10116.ENSRNOP00000050431.

      Chemistry databases

      GuidetoPHARMACOLOGYi547.

      PTM databases

      iPTMnetiQ63099.
      PhosphoSitePlusiQ63099.

      Proteomic databases

      PaxDbiQ63099.
      PRIDEiQ63099.

      Protocols and materials databases

      Structural Biology KnowledgebaseSearch...

      Genome annotation databases

      UCSCiRGD:621349. rat.

      Organism-specific databases

      RGDi621349. Kcnb2.

      Phylogenomic databases

      eggNOGiKOG3713. Eukaryota.
      COG1226. LUCA.
      HOGENOMiHOG000113206.
      HOVERGENiHBG052225.
      InParanoidiQ63099.
      PhylomeDBiQ63099.

      Miscellaneous databases

      PROiQ63099.

      Family and domain databases

      InterProiIPR000210. BTB/POZ_dom.
      IPR005821. Ion_trans_dom.
      IPR003968. K_chnl_volt-dep_Kv.
      IPR003973. K_chnl_volt-dep_Kv2.
      IPR005826. K_chnl_volt-dep_Kv2.2.
      IPR011333. SKP1/BTB/POZ.
      IPR003131. T1-type_BTB.
      IPR028325. VG_K_chnl.
      [Graphical view]
      PANTHERiPTHR11537. PTHR11537. 1 hit.
      PfamiPF02214. BTB_2. 1 hit.
      PF00520. Ion_trans. 1 hit.
      PF03521. Kv2channel. 1 hit.
      [Graphical view]
      PRINTSiPR00169. KCHANNEL.
      PR01515. KV22CHANNEL.
      PR01491. KVCHANNEL.
      PR01495. SHABCHANNEL.
      SMARTiSM00225. BTB. 1 hit.
      [Graphical view]
      SUPFAMiSSF54695. SSF54695. 1 hit.
      ProtoNetiSearch...

      Entry informationi

      Entry nameiKCNB2_RAT
      AccessioniPrimary (citable) accession number: Q63099
      Entry historyi
      Integrated into UniProtKB/Swiss-Prot: July 15, 1998
      Last sequence update: October 25, 2002
      Last modified: November 2, 2016
      This is version 118 of the entry and version 2 of the sequence. [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

      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.