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NamePotassium voltage-gated channel subfamily A member 2
Synonyms
  • NGK1
  • Voltage-gated K(+) channel HuKIV
  • Voltage-gated potassium channel HBK5
  • Voltage-gated potassium channel subunit Kv1.2
Gene NameKCNA2
OrganismHuman
Amino acid sequence
>lcl|BSEQ0008566|Potassium voltage-gated channel subfamily A member 2
MTVATGDPADEAAALPGHPQDTYDPEADHECCERVVINISGLRFETQLKTLAQFPETLLG
DPKKRMRYFDPLRNEYFFDRNRPSFDAILYYYQSGGRLRRPVNVPLDIFSEEIRFYELGE
EAMEMFREDEGYIKEEERPLPENEFQRQVWLLFEYPESSGPARIIAIVSVMVILISIVSF
CLETLPIFRDENEDMHGSGVTFHTYSNSTIGYQQSTSFTDPFFIVETLCIIWFSFEFLVR
FFACPSKAGFFTNIMNIIDIVAIIPYFITLGTELAEKPEDAQQGQQAMSLAILRVIRLVR
VFRIFKLSRHSKGLQILGQTLKASMRELGLLIFFLFIGVILFSSAVYFAEADERESQFPS
IPDAFWWAVVSMTTVGYGDMVPTTIGGKIVGSLCAIAGVLTIALPVPVIVSNFNYFYHRE
TEGEEQAQYLQVTSCPKIPSSPDLKKSRSASTISKSDYMEIQEGVNNSNEDFREENLKTA
NCTLANTNYVNITKMLTDV
Number of residues499
Molecular Weight56716.21
Theoretical pINot Available
GO Classification
Functions
  • voltage-gated potassium channel activity
  • potassium channel activity
  • delayed rectifier potassium channel activity
Processes
  • potassium ion transmembrane transport
  • neuronal action potential
  • protein homooligomerization
  • potassium ion transport
  • regulation of dopamine secretion
  • synaptic transmission
  • sensory perception of pain
Components
  • presynaptic membrane
  • lamellipodium membrane
  • axon
  • neuronal cell body membrane
  • plasma membrane
  • voltage-gated potassium channel complex
  • endoplasmic reticulum membrane
  • lamellipodium
  • cell junction
  • juxtaparanode region of axon
  • integral component of plasma membrane
  • axon terminus
  • dendrite
  • perikaryon
General FunctionVoltage-gated potassium channel activity
Specific FunctionVoltage-gated potassium channel that mediates transmembrane potassium transport in excitable membranes, primarily in the brain and the central nervous system, but also in the cardiovascular system. Prevents aberrant action potential firing and regulates neuronal output. Forms tetrameric potassium-selective channels through which potassium ions pass in accordance with their electrochemical gradient. The channel alternates between opened and closed conformations in response to the voltage difference across the membrane (PubMed:19912772, PubMed:8495559, PubMed:11211111, PubMed:23769686). Can form functional homotetrameric channels and heterotetrameric channels that contain variable proportions of KCNA1, KCNA2, KCNA4, KCNA5, KCNA6, KCNA7, and possibly other family members as well; channel properties depend on the type of alpha subunits that are part of the channel (PubMed:8495559, PubMed:20220134). Channel properties are modulated by cytoplasmic beta subunits that regulate the subcellular location of the alpha subunits and promote rapid inactivation of delayed rectifier potassium channels. 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. Homotetrameric KCNA2 forms a delayed-rectifier potassium channel that opens in response to membrane depolarization, followed by slow spontaneous channel closure (PubMed:19912772, PubMed:23769686). In contrast, a heteromultimer formed by KCNA2 and KCNA4 shows rapid inactivation (PubMed:8495559). Regulates neuronal excitability and plays a role as pacemaker in the regulation of neuronal action potentials (By similarity). KCNA2-containing channels play a presynaptic role and prevent hyperexcitability and aberrant action potential firing (By similarity). Response to toxins that are selective for KCNA2-containing potassium channels suggests that in Purkinje cells, dendritic subthreshold KCNA2-containing potassium channels prevent random spontaneous calcium spikes, suppressing dendritic hyperexcitability without hindering the generation of somatic action potentials, and thereby play an important role in motor coordination (By similarity). Plays a role in the induction of long-term potentiation of neuron excitability in the CA3 layer of the hippocampus (By similarity). May function as down-stream effector for G protein-coupled receptors and inhibit GABAergic inputs to basolateral amygdala neurons (By similarity). May contribute to the regulation of neurotransmitter release, such as gamma-aminobutyric acid (GABA) (By similarity). Contributes to the regulation of the axonal release of the neurotransmitter dopamine (By similarity). Reduced KCNA2 expression plays a role in the perception of neuropathic pain after peripheral nerve injury, but not acute pain (By similarity). Plays a role in the regulation of the time spent in non-rapid eye movement (NREM) sleep (By similarity).
Pfam Domain Function
Transmembrane Regions161-182 222-243 255-275 290-310 326-347 389-417
GenBank Protein IDNot Available
UniProtKB IDP16389
UniProtKB Entry NameKCNA2_HUMAN
Cellular LocationCell membrane
Gene sequence
>lcl|BSEQ0021704|Potassium voltage-gated channel subfamily A member 2 (KCNA2)
ATGACAGTGGCCACCGGAGACCCAGCAGACGAGGCTGCTGCCCTCCCTGGGCACCCACAG
GACACCTATGACCCAGAGGCAGACCACGAGTGCTGTGAGAGGGTGGTGATCAACATCTCA
GGGCTGCGGTTTGAGACCCAGCTAAAGACCTTAGCCCAGTTTCCAGAGACCCTCTTAGGG
GACCCAAAGAAACGAATGAGGTACTTTGACCCCCTCCGAAATGAGTACTTTTTCGATCGG
AACCGCCCTAGCTTTGATGCCATTTTGTACTACTACCAGTCAGGGGGCCGATTGAGGCGA
CCTGTGAATGTGCCCTTAGATATATTCTCTGAAGAAATTCGGTTTTATGAGCTGGGAGAA
GAAGCGATGGAGATGTTTCGGGAAGATGAAGGCTACATCAAGGAGGAAGAGCGTCCTCTG
CCTGAAAATGAGTTTCAGAGACAAGTGTGGCTTCTCTTTGAATACCCAGAGAGCTCAGGG
CCTGCCAGGATTATAGCTATTGTGTCTGTCATGGTGATTCTGATCTCAATTGTCAGCTTC
TGTCTGGAAACATTGCCCATCTTCCGGGATGAGAATGAAGACATGCATGGTAGTGGGGTG
ACCTTCCACACCTATTCCAACAGCACCATCGGGTACCAGCAGTCCACTTCCTTCACAGAC
CCTTTCTTCATTGTAGAGACACTCTGCATCATCTGGTTCTCCTTTGAATTCTTGGTGAGG
TTCTTTGCCTGTCCCAGCAAAGCCGGCTTCTTCACCAACATCATGAACATCATTGACATT
GTGGCCATCATCCCCTACTTCATCACCCTGGGGACAGAGTTGGCTGAGAAGCCAGAGGAC
GCTCAGCAAGGCCAGCAGGCCATGTCACTGGCCATCCTCCGTGTCATCCGGTTGGAACGC
AGACCTCTGCAAAGCCAGAAGAGTAAGCGGGGAAGGCAGCATCTGAACACCTCACATGAC
TGCACCTTAGGAATTAACCTAGTCGCGGGCATGACTGTACAGTGGACCAGGGCATCTGGT
CCTGATGACAGGCAGACACCAGCTGTAACTACATTGCACAGGATGTATTGA
GenBank Gene IDNot Available
GeneCard IDNot Available
GenAtlas IDNot Available
HGNC IDHGNC:6220
Chromosome Location1
LocusNot Available
References
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