KCNA2_ONCMY
ID KCNA2_ONCMY Reviewed; 494 AA.
AC Q9I830;
DT 13-JUL-2010, integrated into UniProtKB/Swiss-Prot.
DT 01-OCT-2000, sequence version 1.
DT 25-MAY-2022, entry version 79.
DE RecName: Full=Potassium voltage-gated channel subfamily A member 2;
DE AltName: Full=Shaker-related potassium channel tsha1 {ECO:0000303|PubMed:9486764};
DE AltName: Full=Trout shaker 1 {ECO:0000303|PubMed:9486764};
DE AltName: Full=Voltage-gated potassium channel subunit Kv1.2;
GN Name=kcna2;
OS Oncorhynchus mykiss (Rainbow trout) (Salmo gairdneri).
OC Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi;
OC Actinopterygii; Neopterygii; Teleostei; Protacanthopterygii; Salmoniformes;
OC Salmonidae; Salmoninae; Oncorhynchus.
OX NCBI_TaxID=8022;
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA], AND TISSUE SPECIFICITY.
RC TISSUE=Brain;
RX PubMed=9486764;
RX DOI=10.1002/(sici)1097-4547(19980201)51:3<284::aid-jnr2>3.0.co;2-c;
RA Nguyen T.-D., Jeserich G.;
RT "Molecular structure and expression of shaker type potassium channels in
RT glial cells of trout CNS.";
RL J. Neurosci. Res. 51:284-292(1998).
CC -!- FUNCTION: Voltage-gated potassium channel that mediates transmembrane
CC potassium transport in excitable membranes, primarily in the brain and
CC central nervous system. Prevents aberrant action potential firing and
CC regulates neuronal output. Forms tetrameric potassium-selective
CC channels through which potassium ions pass in accordance with their
CC electrochemical gradient. The channel alternates between opened and
CC closed conformations in response to the voltage difference across the
CC membrane (By similarity). Can form functional homotetrameric channels
CC and heterotetrameric channels with other family members; the channels
CC characteristics depend critically on the types of channel-forming alpha
CC subunits that are present (By similarity). Channel properties are
CC modulated by cytoplasmic beta subunits that regulate the subcellular
CC location of the alpha subunits (By similarity). In vivo, membranes
CC probably contain a mixture of heteromeric potassium channel complexes,
CC making it difficult to assign currents observed in intact tissues to
CC any particular potassium channel family member. Homotetrameric KCNA2
CC forms a delayed-rectifier potassium channel that opens in response to
CC membrane depolarization, followed by slow spontaneous channel closure
CC (By similarity). Regulates neuronal excitability and plays a role as
CC pacemaker in the regulation of neuronal action potentials (By
CC similarity). KCNA2-containing channels play a presynaptic role and
CC prevent hyperexcitability and aberrant action potential firing (By
CC similarity). Response to toxins that are selective for KCNA2-containing
CC potassium channels suggests that in Purkinje cells, dendritic
CC subthreshold KCNA2-containing potassium channels prevent random
CC spontaneous calcium spikes, suppressing dendritic hyperexcitability
CC without hindering the generation of somatic action potentials, and
CC thereby play an important role in motor coordination (By similarity).
CC Plays a role in the induction of long-term potentiation of neuron
CC excitability in the CA3 layer of the hippocampus (By similarity).
CC {ECO:0000250|UniProtKB:P63141, ECO:0000250|UniProtKB:P63142}.
CC -!- SUBUNIT: Homotetramer and heterotetramer with other family members.
CC {ECO:0000250|UniProtKB:P63142}.
CC -!- SUBCELLULAR LOCATION: Cell membrane {ECO:0000250|UniProtKB:P63142};
CC Multi-pass membrane protein {ECO:0000250|UniProtKB:P63142}.
CC -!- TISSUE SPECIFICITY: Expressed in oligodendrocytes.
CC {ECO:0000269|PubMed:9486764}.
CC -!- DOMAIN: The cytoplasmic N-terminus is important for tetramerization.
CC Interactions between the different subunits modulate the gating
CC characteristics (By similarity). {ECO:0000250|UniProtKB:P63142}.
CC -!- DOMAIN: The transmembrane segment S4 functions as voltage-sensor and is
CC characterized by a series of positively charged amino acids at every
CC third position. Channel opening and closing is effected by a
CC conformation change that affects the position and orientation of the
CC voltage-sensor paddle formed by S3 and S4 within the membrane. A
CC transmembrane electric field that is positive inside would push the
CC positively charged S4 segment outwards, thereby opening the pore, while
CC a field that is negative inside would pull the S4 segment inwards and
CC close the pore. Changes in the position and orientation of S4 are then
CC transmitted to the activation gate formed by the inner helix bundle via
CC the S4-S5 linker region. {ECO:0000250|UniProtKB:P63142}.
CC -!- SIMILARITY: Belongs to the potassium channel family. A (Shaker) (TC
CC 1.A.1.2) subfamily. Kv1.2/KCNA2 sub-subfamily. {ECO:0000305}.
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DR EMBL; AF252301; AAF70087.1; -; Genomic_DNA.
DR AlphaFoldDB; Q9I830; -.
DR SMR; Q9I830; -.
DR OrthoDB; 695337at2759; -.
DR GO; GO:0005887; C:integral component of plasma membrane; ISS:UniProtKB.
DR GO; GO:0044224; C:juxtaparanode region of axon; ISS:UniProtKB.
DR GO; GO:0008076; C:voltage-gated potassium channel complex; ISS:UniProtKB.
DR GO; GO:0005251; F:delayed rectifier potassium channel activity; ISS:UniProtKB.
DR GO; GO:0005249; F:voltage-gated potassium channel activity; ISS:UniProtKB.
DR GO; GO:0019228; P:neuronal action potential; ISS:UniProtKB.
DR GO; GO:0071805; P:potassium ion transmembrane transport; ISS:UniProtKB.
DR GO; GO:0051260; P:protein homooligomerization; IEA:InterPro.
DR GO; GO:0034765; P:regulation of ion transmembrane transport; IEA:UniProtKB-KW.
DR Gene3D; 1.20.120.350; -; 1.
DR Gene3D; 3.30.710.10; -; 1.
DR InterPro; IPR000210; BTB/POZ_dom.
DR InterPro; IPR005821; Ion_trans_dom.
DR InterPro; IPR003968; K_chnl_volt-dep_Kv.
DR InterPro; IPR003972; K_chnl_volt-dep_Kv1.
DR InterPro; IPR004049; K_chnl_volt-dep_Kv1.2.
DR InterPro; IPR011333; SKP1/BTB/POZ_sf.
DR InterPro; IPR003131; T1-type_BTB.
DR InterPro; IPR028325; VG_K_chnl.
DR InterPro; IPR027359; Volt_channel_dom_sf.
DR PANTHER; PTHR11537; PTHR11537; 1.
DR PANTHER; PTHR11537:SF23; PTHR11537:SF23; 1.
DR Pfam; PF02214; BTB_2; 1.
DR Pfam; PF00520; Ion_trans; 1.
DR PRINTS; PR01509; KV12CHANNEL.
DR PRINTS; PR01491; KVCHANNEL.
DR PRINTS; PR01496; SHAKERCHANEL.
DR SMART; SM00225; BTB; 1.
DR SUPFAM; SSF54695; SSF54695; 1.
PE 2: Evidence at transcript level;
KW Cell membrane; Glycoprotein; Ion channel; Ion transport; Lipoprotein;
KW Membrane; Palmitate; Phosphoprotein; Potassium; Potassium channel;
KW Potassium transport; Transmembrane; Transmembrane helix; Transport;
KW Voltage-gated channel.
FT CHAIN 1..494
FT /note="Potassium voltage-gated channel subfamily A member
FT 2"
FT /id="PRO_0000395616"
FT TOPO_DOM 1..159
FT /note="Cytoplasmic"
FT /evidence="ECO:0000250|UniProtKB:P63142"
FT TRANSMEM 160..181
FT /note="Helical; Name=Segment S1"
FT /evidence="ECO:0000250|UniProtKB:P63142"
FT TOPO_DOM 182..216
FT /note="Extracellular"
FT /evidence="ECO:0000250|UniProtKB:P63142"
FT TRANSMEM 217..238
FT /note="Helical; Name=Segment S2"
FT /evidence="ECO:0000250|UniProtKB:P63142"
FT TOPO_DOM 239..249
FT /note="Cytoplasmic"
FT /evidence="ECO:0000250|UniProtKB:P63142"
FT TRANSMEM 250..270
FT /note="Helical; Name=Segment S3"
FT /evidence="ECO:0000250|UniProtKB:P63142"
FT TOPO_DOM 271..284
FT /note="Extracellular"
FT /evidence="ECO:0000250|UniProtKB:P63142"
FT TRANSMEM 285..305
FT /note="Helical; Voltage-sensor; Name=Segment S4"
FT /evidence="ECO:0000250|UniProtKB:P63142"
FT TOPO_DOM 306..320
FT /note="Cytoplasmic"
FT /evidence="ECO:0000250|UniProtKB:P63142"
FT TRANSMEM 321..342
FT /note="Helical; Name=Segment S5"
FT /evidence="ECO:0000250|UniProtKB:P63142"
FT TOPO_DOM 343..356
FT /note="Extracellular"
FT /evidence="ECO:0000250|UniProtKB:P63142"
FT INTRAMEM 357..368
FT /note="Helical; Name=Pore helix"
FT /evidence="ECO:0000250|UniProtKB:P63142"
FT INTRAMEM 369..376
FT /evidence="ECO:0000250|UniProtKB:P63142"
FT TOPO_DOM 377..383
FT /note="Extracellular"
FT /evidence="ECO:0000250|UniProtKB:P63142"
FT TRANSMEM 384..412
FT /note="Helical; Name=Segment S6"
FT /evidence="ECO:0000250|UniProtKB:P63142"
FT TOPO_DOM 413..494
FT /note="Cytoplasmic"
FT /evidence="ECO:0000250|UniProtKB:P63142"
FT REGION 1..124
FT /note="Tetramerization domain"
FT /evidence="ECO:0000250|UniProtKB:P63142"
FT REGION 1..25
FT /note="Disordered"
FT /evidence="ECO:0000256|SAM:MobiDB-lite"
FT REGION 307..320
FT /note="S4-S5 linker"
FT /evidence="ECO:0000250|UniProtKB:P63142"
FT MOTIF 369..374
FT /note="Selectivity filter"
FT /evidence="ECO:0000250|UniProtKB:P63142"
FT MOTIF 492..494
FT /note="PDZ-binding"
FT /evidence="ECO:0000250|UniProtKB:P63142"
FT SITE 376
FT /note="Important for binding with the scorpion
FT mesomartoxin; when the scorpion mesomartoxin-rKv1.2/KCNA2
FT interaction is modeled, this residue is close to the 'Y-57'
FT residue of the toxin"
FT /evidence="ECO:0000250|UniProtKB:P63142"
FT LIPID 239
FT /note="S-palmitoyl cysteine"
FT /evidence="ECO:0000255"
FT CARBOHYD 203
FT /note="N-linked (GlcNAc...) asparagine"
FT /evidence="ECO:0000255"
SQ SEQUENCE 494 AA; 55900 MW; AF66998F97F22CD4 CRC64;
MTVATGDPSD EAAAHPGNPA EYDPDADHEC CERVVINISG LRFETQLKTL SQFPDTLLGD
PKKRMRYFDP LRNEYFFDRS RTSFDAILYF YQSGGRLRRP ANVTLDIFSE EIRFYELGDE
AIELFREDEG FVKEEERPLP DNEFQRQVWL LFEYPESSGP ARIIAIISVM VILISIVSFC
LETLPIFRND DDEPHSVFDT NTNTTIYFTS TYFTDPFFIL ETLCIIWFSF EFLVRLFACP
SKSGFFGNVM NIIDVVAIIP YFITLATELA EKPEDGQAGQ QAMSLAILRV IRLVRVFRIF
KLSRHSKGLQ ILGQTLKASM RELGLLIFFL FIGVILFSSA VYFAEADEPE SQFESIPDAF
WWAVVSMTTV GYGDMVPTTI GGKIVGSLCA IAGVLTIALP VPVIVSNFNY FYHRETEGEE
QAQCLGPVTK EDSNEELKKS RSGSTISKSD YMEIQEGVNN TIEDIPEENL KTQANCTTLA
NTNYVNITKM LTDV
