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Protein

Potassium voltage-gated channel subfamily B member 2

Gene

KCNB2

Organism
Homo sapiens (Human)
Status
Reviewed-Annotation score: Annotation score: 5 out of 5-Experimental evidence at transcript leveli

Functioni

Voltage-gated potassium channel that mediates transmembrane potassium transport in excitable membranes, primarily in the brain and smooth muscle cells. 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. 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. 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. 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.By similarity

Enzyme regulationi

Inhibited by quinine at micromolar levels. Modestly sensitive to millimolar levels of tetraethylammonium (TEA) and 4-aminopyridine (4-AP).By similarity1 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. After that, inactivate very slowly. 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.By similarity

1 Publication

      GO - Molecular functioni

      GO - Biological processi

      Complete GO annotation...

      Keywords - Molecular functioni

      Ion channel, Potassium channel, Voltage-gated channel

      Keywords - Biological processi

      Ion transport, Potassium transport, Transport

      Keywords - Ligandi

      Potassium

      Enzyme and pathway databases

      ReactomeiREACT_75770. Voltage gated Potassium channels.

      Names & Taxonomyi

      Protein namesi
      Recommended name:
      Potassium voltage-gated channel subfamily B member 2Imported
      Alternative name(s):
      Voltage-gated potassium channel subunit Kv2.2
      Gene namesi
      Name:KCNB2Imported
      OrganismiHomo sapiens (Human)
      Taxonomic identifieri9606 [NCBI]
      Taxonomic lineageiEukaryotaMetazoaChordataCraniataVertebrataEuteleostomiMammaliaEutheriaEuarchontogliresPrimatesHaplorrhiniCatarrhiniHominidaeHomo
      ProteomesiUP000005640 Componenti: Chromosome 8

      Organism-specific databases

      HGNCiHGNC:6232. KCNB2.

      Subcellular locationi

      • Cell membrane By similarity; Multi-pass membrane protein By similarity
      • Perikaryon By similarity
      • Cell projectiondendrite By similarity

      • Note: Localized uniformly throughout cell bodies and dendrites. Colocalizes with KCNB1 to high-density somatodendritic clusters on cortical pyramidal neurons.By similarity

      Topology

      Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
      Topological domaini1 – 190190CytoplasmicBy similarityAdd
      BLAST
      Transmembranei191 – 21222Helical; Name=Segment S1By similarityAdd
      BLAST
      Topological domaini213 – 23220ExtracellularBy similarityAdd
      BLAST
      Transmembranei233 – 25422Helical; Name=Segment S2By similarityAdd
      BLAST
      Topological domaini255 – 26511CytoplasmicBy similarityAdd
      BLAST
      Transmembranei266 – 28419Helical; Name=Segment S3By similarityAdd
      BLAST
      Topological domaini285 – 29612ExtracellularBy similarityAdd
      BLAST
      Transmembranei297 – 31721Helical; Voltage-sensor; Name=Segment S4By similarityAdd
      BLAST
      Topological domaini318 – 33215CytoplasmicBy similarityAdd
      BLAST
      Transmembranei333 – 35422Helical; Name=Segment S5By similarityAdd
      BLAST
      Topological domaini355 – 36814ExtracellularBy similarityAdd
      BLAST
      Intramembranei369 – 38012Helical; Name=Pore helixBy similarityAdd
      BLAST
      Intramembranei381 – 3888By similarity
      Topological domaini389 – 3957ExtracellularBy similarity
      Transmembranei396 – 42429Helical; Name=Segment S6By similarityAdd
      BLAST
      Topological domaini425 – 911487CytoplasmicBy similarityAdd
      BLAST

      GO - Cellular componenti

      Complete GO annotation...

      Keywords - Cellular componenti

      Cell membrane, Cell projection, Membrane

      Pathology & Biotechi

      Organism-specific databases

      PharmGKBiPA30025.

      Chemistry

      DrugBankiDB06637. Dalfampridine.

      Polymorphism and mutation databases

      BioMutaiKCNB2.
      DMDMi24418855.

      PTM / Processingi

      Molecule processing

      Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
      Chaini1 – 911911Potassium voltage-gated channel subfamily B member 2PRO_0000054048Add
      BLAST

      Amino acid modifications

      Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
      Glycosylationi287 – 2871N-linked (GlcNAc...)Sequence Analysis

      Post-translational modificationi

      Phosphorylated.By similarity

      Keywords - PTMi

      Glycoprotein, Phosphoprotein

      Proteomic databases

      PaxDbiQ92953.
      PRIDEiQ92953.

      PTM databases

      PhosphoSiteiQ92953.

      Expressioni

      Gene expression databases

      BgeeiQ92953.
      CleanExiHS_KCNB2.
      GenevisibleiQ92953. HS.

      Interactioni

      Subunit structurei

      Homotetramer or heterotetramer with KCNB1. Heterotetramer with KCNS1 and KCNS2.By similarity

      Protein-protein interaction databases

      BioGridi114724. 5 interactions.
      IntActiQ92953. 1 interaction.
      STRINGi9606.ENSP00000430846.

      Structurei

      3D structure databases

      ProteinModelPortaliQ92953.
      SMRiQ92953. Positions 34-466.
      ModBaseiSearch...
      MobiDBiSearch...

      Family & Domainsi

      Motif

      Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
      Motifi381 – 3866Selectivity filterBy similarity

      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

      eggNOGiCOG1226.
      GeneTreeiENSGT00760000118981.
      HOGENOMiHOG000113206.
      HOVERGENiHBG052225.
      InParanoidiQ92953.
      KOiK04886.
      OMAiIHSNPGD.
      OrthoDBiEOG7CRTPP.
      PhylomeDBiQ92953.
      TreeFamiTF313103.

      Family and domain databases

      InterProiIPR000210. BTB/POZ-like.
      IPR011333. BTB/POZ_fold.
      IPR005821. Ion_trans_dom.
      IPR003091. K_chnl.
      IPR003968. K_chnl_volt-dep_Kv.
      IPR003973. K_chnl_volt-dep_Kv2.
      IPR005826. K_chnl_volt-dep_Kv2.2.
      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.

      Q92953-1 [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 EREGEEFDNT CCPDKRKKLW DLLEKPNSSV AAKILAIVSI
      210 220 230 240 250
      LFIVLSTIAL SLNTLPELQE TDEFGQLNDN RQLAHVEAVC 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 KAGESANTKD SADDNHLSPS RWKWARKALS
      510 520 530 540 550
      ETSSNKSFEN KYQEVSQKDS HEQLNNTSSS SPQHLSAQKL EMLYNEITKT
      560 570 580 590 600
      QPHSHPNPDC QEKPERPSAY EEEIEMEEVV CPQEQLAVAQ TEVIVDMKST
      610 620 630 640 650
      SSIDSFTSCA TDFTETERSP LPPPSASHLQ MKFPTDLPGT EEHQRARGPP
      660 670 680 690 700
      FLTLSREKGP AARDGTLEYA PVDITVNLDA SGSQCGLHSP LQSDNATDSP
      710 720 730 740 750
      KSSLKGSNPL KSRSLKVNFK ENRGSAPQTP PSTARPLPVT TADFSLTTPQ
      760 770 780 790 800
      HISTILLEET PSQGDRPLLG TEVSAPCQGP SKGLSPRFPK QKLFPFSSRE
      810 820 830 840 850
      RRSFTEIDTG DDEDFLELPG AREEKQVDSS PNCFADKPSD GRDPLREEGS
      860 870 880 890 900
      VGSSSPQDTG HNCRQDIYHA VSEVKKDSSQ EGCKMENHLF APEIHSNPGD
      910
      TGYCPTRETS M
      Length:911
      Mass (Da):102,563
      Last modified:October 25, 2002 - v2
      Checksum:i2261D7D6280CF81A
      GO

      Sequence cautioni

      The sequence AAB08433.1 differs from that shown. Reason: Frameshift at position 768. Curated

      Experimental Info

      Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
      Sequence conflicti161 – 1622ER → DG in AAP46292 (Ref. 1) Curated
      Sequence conflicti528 – 5281S → F in AAP46292 (Ref. 1) Curated

      Natural variant

      Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
      Natural varianti450 – 4501V → I in a colorectal cancer sample; somatic mutation. 1 Publication
      VAR_035774
      Natural varianti657 – 6571E → G.
      Corresponds to variant rs16938507 [ dbSNP | Ensembl ].
      VAR_034050

      Sequence databases

      Select the link destinations:
      EMBLi
      GenBanki
      DDBJi
      Links Updated
      AF450111 mRNA. Translation: AAP46292.1.
      AF338730 mRNA. Translation: AAK16585.1.
      U69962 mRNA. Translation: AAB08433.1. Frameshift.
      CCDSiCCDS6209.1.
      RefSeqiNP_004761.2. NM_004770.2.
      UniGeneiHs.661102.

      Genome annotation databases

      EnsembliENST00000523207; ENSP00000430846; ENSG00000182674.
      GeneIDi9312.
      KEGGihsa:9312.
      UCSCiuc003xzb.3. human.

      Keywords - Coding sequence diversityi

      Polymorphism

      Cross-referencesi

      Sequence databases

      Select the link destinations:
      EMBLi
      GenBanki
      DDBJi
      Links Updated
      AF450111 mRNA. Translation: AAP46292.1.
      AF338730 mRNA. Translation: AAK16585.1.
      U69962 mRNA. Translation: AAB08433.1. Frameshift.
      CCDSiCCDS6209.1.
      RefSeqiNP_004761.2. NM_004770.2.
      UniGeneiHs.661102.

      3D structure databases

      ProteinModelPortaliQ92953.
      SMRiQ92953. Positions 34-466.
      ModBaseiSearch...
      MobiDBiSearch...

      Protein-protein interaction databases

      BioGridi114724. 5 interactions.
      IntActiQ92953. 1 interaction.
      STRINGi9606.ENSP00000430846.

      Chemistry

      BindingDBiQ92953.
      ChEMBLiCHEMBL2321618.
      DrugBankiDB06637. Dalfampridine.
      GuidetoPHARMACOLOGYi547.

      PTM databases

      PhosphoSiteiQ92953.

      Polymorphism and mutation databases

      BioMutaiKCNB2.
      DMDMi24418855.

      Proteomic databases

      PaxDbiQ92953.
      PRIDEiQ92953.

      Protocols and materials databases

      DNASUi9312.
      Structural Biology KnowledgebaseSearch...

      Genome annotation databases

      EnsembliENST00000523207; ENSP00000430846; ENSG00000182674.
      GeneIDi9312.
      KEGGihsa:9312.
      UCSCiuc003xzb.3. human.

      Organism-specific databases

      CTDi9312.
      GeneCardsiGC08P073499.
      HGNCiHGNC:6232. KCNB2.
      MIMi607738. gene.
      neXtProtiNX_Q92953.
      PharmGKBiPA30025.
      GenAtlasiSearch...

      Phylogenomic databases

      eggNOGiCOG1226.
      GeneTreeiENSGT00760000118981.
      HOGENOMiHOG000113206.
      HOVERGENiHBG052225.
      InParanoidiQ92953.
      KOiK04886.
      OMAiIHSNPGD.
      OrthoDBiEOG7CRTPP.
      PhylomeDBiQ92953.
      TreeFamiTF313103.

      Enzyme and pathway databases

      ReactomeiREACT_75770. Voltage gated Potassium channels.

      Miscellaneous databases

      GeneWikiiKCNB2.
      GenomeRNAii9312.
      NextBioi34883.
      PROiQ92953.
      SOURCEiSearch...

      Gene expression databases

      BgeeiQ92953.
      CleanExiHS_KCNB2.
      GenevisibleiQ92953. HS.

      Family and domain databases

      InterProiIPR000210. BTB/POZ-like.
      IPR011333. BTB/POZ_fold.
      IPR005821. Ion_trans_dom.
      IPR003091. K_chnl.
      IPR003968. K_chnl_volt-dep_Kv.
      IPR003973. K_chnl_volt-dep_Kv2.
      IPR005826. K_chnl_volt-dep_Kv2.2.
      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...

      Publicationsi

      « Hide 'large scale' publications
      1. "Cloning and characterization of two novel gamma Kv subunits."
        Preisig-Mueller R., Derst C., Schnitzler M.M., Daut J.
        Submitted (NOV-2001) to the EMBL/GenBank/DDBJ databases
        Cited for: NUCLEOTIDE SEQUENCE [MRNA].
        Tissue: Brain.
      2. Rae J.L.
        Submitted (JAN-2001) to the EMBL/GenBank/DDBJ databases
        Cited for: NUCLEOTIDE SEQUENCE [MRNA].
      3. "Molecular identification of a component of delayed rectifier current in gastrointestinal smooth muscles."
        Schmalz F., Kinsella J., Koh S.D., Vogalis F., Schneider A., Flynn E.R., Kenyon J.L., Horowitz B.
        Am. J. Physiol. 274:G901-G911(1998) [PubMed] [Europe PMC] [Abstract]
        Cited for: NUCLEOTIDE SEQUENCE [MRNA] OF 1-811.
      4. Cited for: REVIEW.
      5. Cited for: VARIANT [LARGE SCALE ANALYSIS] ILE-450.

      Entry informationi

      Entry nameiKCNB2_HUMAN
      AccessioniPrimary (citable) accession number: Q92953
      Secondary accession number(s): Q7Z7D0, Q9BXD3
      Entry historyi
      Integrated into UniProtKB/Swiss-Prot: December 15, 1998
      Last sequence update: October 25, 2002
      Last modified: July 22, 2015
      This is version 137 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 8
        Human chromosome 8: 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

      External Data

      Dasty 3

      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 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.