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Potassium voltage-gated channel subfamily A member 1



Mus musculus (Mouse)
Reviewed-Annotation score: -Experimental evidence at protein leveli


Voltage-gated potassium channel that mediates transmembrane potassium transport in excitable membranes, primarily in the brain and the central nervous system, but also in the kidney. Contributes to the regulation of the membrane potential and nerve signaling, and prevents neuronal hyperexcitability (PubMed:9736643, PubMed:9581771 PubMed:10191303, PubMed:12611922, PubMed:21966978, PubMed:22158511, PubMed:23473320). 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:15361858). 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. 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 (PubMed:15361858). 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 KCNA1 forms a delayed-rectifier potassium channel that opens in response to membrane depolarization, followed by slow spontaneous channel closure (PubMed:7517498, PubMed:15361858). In contrast, a heterotetrameric channel formed by KCNA1 and KCNA4 shows rapid inactivation (By similarity). Regulates neuronal excitability in hippocampus, especially in mossy fibers and medial perforant path axons, preventing neuronal hyperexcitability (PubMed:23466697). 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) release (By similarity). Plays a role in regulating the generation of action potentials and preventing hyperexcitability in myelinated axons of the vagus nerve, and thereby contributes to the regulation of heart contraction (PubMed:20392939, PubMed:22641786, PubMed:25377007). Required for normal neuromuscular responses (PubMed:9736643). Regulates the frequency of neuronal action potential firing in response to mechanical stimuli, and plays a role in the perception of pain caused by mechanical stimuli, but does not play a role in the perception of pain due to heat stimuli (PubMed:23473320). Required for normal responses to auditory stimuli and precise location of sound sources, but not for sound perception (PubMed:21966978, PubMed:22396426). The use of toxins that block specific channels suggest that it contributes to the regulation of the axonal release of the neurotransmitter dopamine (PubMed:21233214). Required for normal postnatal brain development and normal proliferation of neuronal precursor cells in the brain (PubMed:8995755, PubMed:17250763, PubMed:17315199, PubMed:22411008). Plays a role in the reabsorption of Mg2+ in the distal convoluted tubules in the kidney and in magnesium ion homeostasis, probably via its effect on the membrane potential (By similarity).By similarity19 Publications


The delay or D-type current observed in hippocampus pyramidal neurons is probably mediated by potassium channels containing KCNA2 plus KCNA1 or other family members. It is activated at about -50 mV, i.e. below the action potential threshold, and is characterized by slow inactivation, extremely slow recovery from inactivation, sensitivity to dendrotoxin (DTX) and to 4-aminopyridine (4-AP).1 Publication

Enzyme regulationi

Inhibited by 4-aminopyridine (4-AP), tetraethylammonium (TEA) and dendrotoxin (DTX), but not by charybdotoxin (CTX).1 Publication

GO - Molecular functioni

  • delayed rectifier potassium channel activity Source: UniProtKB
  • disordered domain specific binding Source: MGI
  • voltage-gated potassium channel activity Source: UniProtKB

GO - Biological processi

  • brain development Source: UniProtKB
  • cell communication by electrical coupling Source: UniProtKB
  • cellular protein localization Source: Ensembl
  • cellular response to magnesium ion Source: UniProtKB
  • detection of mechanical stimulus involved in sensory perception of pain Source: UniProtKB
  • detection of mechanical stimulus involved in sensory perception of touch Source: UniProtKB
  • hippocampus development Source: UniProtKB
  • magnesium ion homeostasis Source: UniProtKB
  • neuroblast proliferation Source: UniProtKB
  • neuromuscular process Source: UniProtKB
  • neuronal action potential Source: UniProtKB
  • neuronal signal transduction Source: UniProtKB
  • positive regulation of voltage-gated potassium channel activity Source: Ensembl
  • potassium ion transmembrane transport Source: UniProtKB
  • protein homooligomerization Source: InterPro
  • regulation of membrane potential Source: UniProtKB
  • regulation of muscle contraction Source: UniProtKB
  • startle response Source: UniProtKB


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

Enzyme and pathway databases

ReactomeiR-MMU-1296072 Voltage gated Potassium channels

Names & Taxonomyi

Protein namesi
Recommended name:
Potassium voltage-gated channel subfamily A member 1
Alternative name(s):
MBK11 Publication
Voltage-gated potassium channel subunit Kv1.1
Gene namesi
OrganismiMus musculus (Mouse)
Taxonomic identifieri10090 [NCBI]
Taxonomic lineageiEukaryotaMetazoaChordataCraniataVertebrataEuteleostomiMammaliaEutheriaEuarchontogliresGliresRodentiaMyomorphaMuroideaMuridaeMurinaeMusMus
  • UP000000589 Componenti: Chromosome 6

Organism-specific databases

MGIiMGI:96654 Kcna1

Subcellular locationi

Extracellular region or secreted Cytosol Plasma membrane Cytoskeleton Lysosome Endosome Peroxisome ER Golgi apparatus Nucleus Mitochondrion Manual annotation Automatic computational assertionGraphics by Christian Stolte; Source: COMPARTMENTS


Feature keyPosition(s)DescriptionActionsGraphical viewLength
Topological domaini1 – 164CytoplasmicBy similarityAdd BLAST164
Transmembranei165 – 186Helical; Name=Segment S1By similarityAdd BLAST22
Topological domaini187 – 220ExtracellularBy similarityAdd BLAST34
Transmembranei221 – 242Helical; Name=Segment S2By similarityAdd BLAST22
Topological domaini243 – 253CytoplasmicBy similarityAdd BLAST11
Transmembranei254 – 274Helical; Name=Segment S3By similarityAdd BLAST21
Topological domaini275 – 287ExtracellularBy similarityAdd BLAST13
Transmembranei288 – 308Helical; Voltage-sensor; Name=Segment S4By similarityAdd BLAST21
Topological domaini309 – 323CytoplasmicBy similarityAdd BLAST15
Transmembranei324 – 345Helical; Name=Segment S5By similarityAdd BLAST22
Topological domaini346 – 359ExtracellularBy similarityAdd BLAST14
Intramembranei360 – 371Helical; Name=Pore helixBy similarityAdd BLAST12
Intramembranei372 – 379By similarity8
Topological domaini380 – 386ExtracellularBy similarity7
Transmembranei387 – 415Helical; Name=Segment S6By similarityAdd BLAST29
Topological domaini416 – 495CytoplasmicBy similarityAdd BLAST80

Keywords - Cellular componenti

Cell junction, Cell membrane, Cell projection, Cytoplasmic vesicle, Endoplasmic reticulum, Membrane, Synapse

Pathology & Biotechi

Involvement in diseasei

A spontaneous mutation leading to a frameshift and truncation of Kcna2 causes megencephaly with a 25% increase of brain weight relative to wild-type. Especially the hippocampus shows increased proliferation of neurons and astrocytes, leading to increased brain volume (PubMed:17315199). Mutant mice appear normal at birth. After 3-4 weeks, they display low body weight, a subtle shakiness in their gait, a preference for a strange sitting position that is maintained for periods ranging from 30 seconds to several minutes, excessive lacrimation and acoustic startle hypersensitivity (PubMed:8995755, PubMed:21966978). The increase in the acoustic startle response is down-regulated by treatment with the anti-epileptic drug valproate (PubMed:21966978). Mutant mice display an abnormal electro-encephalogram with single spikes and waves, when anesthesized (PubMed:21966978). The electric activity of mossy cells from the dentate hilus region is altered and shows increased firing of action potentials, probably due to the absence of functional Kcna1 channels (PubMed:14686897). Heterozygotes show mechanical allodynia, but no increased sensitivity to heat (PubMed:23473320). Homozygotes show no alteration of the islet of Langerhans structure, of the basal levels of insulin secretion and blood glucose levels (PubMed:21483673). Compared to wild-type, they display moderately increased insulin secretion in response to a glucose stimulus (PubMed:21483673). Besides, the frequency of beta cell action potentials is increased (PubMed:21483673).5 Publications

Disruption phenotypei

Mice are born at the expected Mendelian rate. After three weeks, mice begin to display episodic eye blinking, twitching of whiskers, forlimb padding, arrested motion and a hyperstartle response. About 50% of the homozygotes die between the third and the fifth week after birth. Surviving mice continue to display spontaneous seizures occurring once or twice every hour throughout adult life (PubMed:9581771). The fecundity of homozygotes is extremely low (PubMed:9581771). Mutant mice display interictal cardiac abnormalities, including a fivefold increase in atrioventricular conduction blocks, brachycardia and premature ventricular contractions; this may lead to sudden unexplained death in epilepsy (PubMed:20392939). Mutant mice have slightly elevated heart rates; they all have a reduced livespan and are subject to sudden death after presumed seizure activity and sinus bradycardia (PubMed:25377007). About 70% of the mutant mice have an enlarged hippocampus and ventral brain cortex (PubMed:17250763). Mutant mice show a temperature-sensitive alteration in neuromuscular transmission, causing nerve hyperexcitability when exposed to cold and delayed repetitive discharge after a single nerve stimulation (PubMed:9736643). After 2 minutes of swimming in cold water, mutant mice have impaired motor control; they fall over when placed on dry ground and exhibit severe neuromyotonia with violent tremors that decrease with time, leading to full recovery after twenty minutes (PubMed:9736643). Mutant mice have an increased frequency of spontaneous postsynaptic currents in Purkinje cells, impaired ability to maintain their balance on a thin stationary rod, but perform as well as wild-type on a rotarod (PubMed:10191303). Mutant mice have a normal hearing threshold, but altered brainstem responses to auditory stimuli and reduced sensitivity to small changes in sound location (PubMed:22396426). Mutant mice display no alteration of the islet of Langerhans, but have reduced blood glucose levels and increased insulin secretion in response to a glucose stimulus (PubMed:21483673).8 Publications

Chemistry databases


PTM / Processingi

Molecule processing

Feature keyPosition(s)DescriptionActionsGraphical viewLength
ChainiPRO_00000539691 – 495Potassium voltage-gated channel subfamily A member 1Add BLAST495

Amino acid modifications

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Modified residuei23PhosphoserineBy similarity1
Glycosylationi207N-linked (GlcNAc...) asparagineSequence analysis1
Lipidationi243S-palmitoyl cysteineBy similarity1
Modified residuei322Phosphoserine; by PKASequence analysis1
Modified residuei437PhosphoserineBy similarity1
Modified residuei439PhosphoserineBy similarity1
Modified residuei446Phosphoserine; by PKABy similarity1

Post-translational modificationi

N-glycosylated.By similarity
Palmitoylated on Cys-243; which may be required for membrane targeting.By similarity
Phosphorylated on tyrosine residues. Phosphorylation increases in response to NRG1; this inhibits channel activity (PubMed:22158511). Phosphorylation at Ser-446 regulates channel activity by down-regulating expression at the cell membrane (By similarity).By similarity1 Publication

Keywords - PTMi

Glycoprotein, Lipoprotein, Palmitate, Phosphoprotein

Proteomic databases


PTM databases



Tissue specificityi

Detected in brain (PubMed:21483673, PubMed:22158511). Detected in the juxtaparanodal regions of the nodes of Ranvier in myelinated axons (PubMed:8361541, PubMed:8046438). Detected in the paranodal region in sciatic nerve (PubMed:9736643). Detected on cell bodies in cerebellum, dorsal and ventral cochlear nucleus, pontine reticular nucleus, mesencephalic trigeminal nucleus, motor trigeminal nucleus and the pricipal sensory trigeminal nucleus (PubMed:8046438). Detected in terminal fields of basket cells in the cerebellum corpus medullare (PubMed:8361541, PubMed:8046438, PubMed:9581771). Detected in hippocampus CA3 pyramidal neurons and in the hilus and stratum moleculare of the dentate gyrus (PubMed:8046438, PubMed:9581771, PubMed:14686897). Detected in the central nucleus and the external nucleus of the inferior colliculus (PubMed:8046438, PubMed:21966978). Detected in fiber tracts in the optic tract, external medullary lamina, stria terminalis, medulla, ventral pallidum and substantia nigra (PubMed:8046438). Detected in neurons from dorsal root ganglion (PubMed:23473320). Detected in neurons in the medial nucleus of the trapezoid body (PubMed:12611922). Detected in midbrain dopamine neuron axon terminals (PubMed:21233214). Detected in brain cortex (PubMed:8046438, PubMed:14686897). Detected in brainstem (PubMed:8361541). Detected in juxtaparanodal regions of the nodes of Ranvier in the vagus nerve, but only at very low levels in the heart (PubMed:20392939, PubMed:22641786). Detected in the islet of Langerhans (PubMed:21483673). Detected at the luminal membrane in distal convoluted tubules in the kidney (at protein level) (PubMed:19307729). Detected in brain (PubMed:2451788, PubMed:9581771). Detected in hippocampus, thalamus, neocortex and ventral brain cortex, including the piriform and entorhinal cortex and the amygdala (PubMed:14686897). Detected in midbrain dopamine neurons (PubMed:21233214). Detected in heart atrium, ventricle, sinoatrial node and atrioventricular node (PubMed:20392939). Detected in the islet of Langerhans (PubMed:21483673).15 Publications


Down-regulated by high dietary Mg2+ levels.1 Publication

Gene expression databases

GenevisibleiP16388 MM


Subunit structurei

Homotetramer and heterotetramer with other channel-forming alpha subunits, such as KCNA2, KCNA4, KCNA5, KCNA6 and KCNA7 (PubMed:8361541). Channel activity is regulated by interaction with the beta subunits KCNAB1 and KCNAB2 (PubMed:15361858). Identified in a complex with KCNA2 and KCNAB2. Interacts (via C-terminus) with the PDZ domains of DLG1, DLG2 and DLG4 (By similarity). Interacts with LGI1 within a complex containing LGI1, KCNA4 and KCNAB1 (By similarity). Interacts (via N-terminus) with STX1A; this promotes channel inactivation (By similarity). Interacts (via N-terminus) with the heterodimer formed by GNB1 and GNG2; this promotes channel inactivation (By similarity). Can interact simultaneously with STX1A and the heterodimer formed by GNB1 and GNG2 (By similarity). Interacts (via cytoplasmic N-terminal domain) with KCNRG; this inhibits channel activity (By similarity). Interacts with ANK3; this inhibits channel activity (PubMed:23903368).By similarityCurated3 Publications

GO - Molecular functioni

Protein-protein interaction databases

BioGridi200876, 3 interactors
IntActiP16388, 3 interactors


3D structure databases


Family & Domainsi


Feature keyPosition(s)DescriptionActionsGraphical viewLength
Regioni1 – 128Tetramerization domainBy similarityAdd BLAST128
Regioni310 – 323S4-S5 linkerBy similarityAdd BLAST14


Feature keyPosition(s)DescriptionActionsGraphical viewLength
Motifi372 – 377Selectivity filterBy similarity6
Motifi493 – 495PDZ-bindingBy similarity3


The cytoplasmic N-terminus is important for tetramerization and for interaction with the beta subunits that promote rapid channel closure.By similarity
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

eggNOGiKOG1545 Eukaryota

Family and domain databases

Gene3Di1.20.120.350, 1 hit
InterProiView protein in InterPro
IPR000210 BTB/POZ_dom
IPR005821 Ion_trans_dom
IPR003968 K_chnl_volt-dep_Kv
IPR003972 K_chnl_volt-dep_Kv1
IPR004048 K_chnl_volt-dep_Kv1.1
IPR011333 SKP1/BTB/POZ_sf
IPR003131 T1-type_BTB
IPR028325 VG_K_chnl
IPR027359 Volt_channel_dom_sf
PANTHERiPTHR11537 PTHR11537, 1 hit
PfamiView protein in Pfam
PF02214 BTB_2, 1 hit
PF00520 Ion_trans, 1 hit
SMARTiView protein in SMART
SM00225 BTB, 1 hit
SUPFAMiSSF54695 SSF54695, 1 hit


Sequence statusi: Complete.

P16388-1 [UniParc]FASTAAdd to basket

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Mass (Da):56,409
Last modified:August 1, 1990 - v1

RNA editingi

Edited at position 400.1 Publication
Partially edited. RNA editing varies from 35% in the frontal cortex to 75% in the spinal chord.

Natural variant

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Natural varianti400I → V in RNA edited version. 1

Sequence databases

Select the link destinations:
Links Updated
M30439 Genomic DNA Translation: AAA39711.1
Y00305 mRNA Translation: CAA68408.1
RefSeqiNP_034725.3, NM_010595.3

Genome annotation databases

EnsembliENSMUST00000055168; ENSMUSP00000055225; ENSMUSG00000047976
ENSMUST00000203094; ENSMUSP00000144947; ENSMUSG00000047976
UCSCiuc009dvb.1 mouse

Keywords - Coding sequence diversityi

RNA editing

Similar proteinsi

Entry informationi

Entry nameiKCNA1_MOUSE
AccessioniPrimary (citable) accession number: P16388
Entry historyiIntegrated into UniProtKB/Swiss-Prot: August 1, 1990
Last sequence update: August 1, 1990
Last modified: March 28, 2018
This is version 161 of the entry and version 1 of the sequence. See complete history.
Entry statusiReviewed (UniProtKB/Swiss-Prot)
Annotation programChordata Protein Annotation Program


Keywords - Technical termi

Complete proteome, Reference proteome
UniProt is an ELIXIR core data resource
Main funding by: National Institutes of Health