KCNA1 - Potassium voltage-gated channel subfamily A member 1 - human protein (Function)
 
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KCNA1 »  Potassium voltage-gated channel subfamily A member 1
 
Protein also known as:  Voltage-gated potassium channel subunit Kv1.1.
Gene name:  KCNA1
Entry whose protein(s) existence is based on evidence at protein level
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1 66 1
GENE REF ISO

Function

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Overview 
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 (PubMed19903818). Contributes to the regulation of the membrane potential and nerve signaling, and prevents neuronal hyperexcitability (PubMed17156368). 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 (PubMed19912772). 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 (PubMed12077175, PubMed17156368). 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 (PubMed12077175, PubMed17156368). 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 (PubMed19912772, PubMed19968958, PubMed19307729, PubMed19903818). In contrast, a heterotetrameric channel formed by KCNA1 and KCNA4 shows rapid inactivation (PubMed17156368). Regulates neuronal excitability in hippocampus, especially in mossy fibers and medial perforant path axons, preventing neuronal hyperexcitability. Response to toxins that are selective for KCNA1, respectively for KCNA2, suggests that heteromeric potassium channels composed of both KCNA1 and KCNA2 play a role in pacemaking and regulate the output of deep cerebellar nuclear neurons (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) 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 (By similarity). Required for normal neuromuscular responses (PubMed11026449, PubMed17136396). 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 (By similarity). Required for normal responses to auditory stimuli and precise location of sound sources, but not for sound perception (By similarity). The use of toxins that block specific channels suggest that it contributes to the regulation of the axonal release of the neurotransmitter dopamine (By similarity). Required for normal postnatal brain development and normal proliferation of neuronal precursor cells in the brain (By similarity). Plays a role in the reabsorption of Mg(2+) in the distal convoluted tubules in the kidney and in magnesium ion homeostasis, probably via its effect on the membrane potential (PubMed23903368, PubMed19307729).  
13
  • UniProtKB
According to TCDB this is a transporter from family:
the voltage-gated ion channel (vic) superfamily  1.A.1.2.12  
GO molecular function 
Delayed rectifier potassium channel activitydefinition[GO:0005251]  
2
  • UniProtKB
  • RefGenome
Potassium channel activitydefinition[GO:0005267]  
1
  • PINC
Potassium ion transmembrane transporter activitydefinition[GO:0015079]  
1
  • PINC
Protein bindingdefinition[GO:0005515]  
3
  • UniProtKB
  • IntAct
Voltage-gated potassium channel activitydefinition[GO:0005249]  
1
  • UniProtKB
GO biological process 
Cell communication by electrical couplingdefinition[GO:0010644]  
1
  • Ortholog Curator
Cellular response to magnesium iondefinition[GO:0071286]  
1
  • Ortholog Curator
Detection of mechanical stimulus involved in sensory perception of paindefinition[GO:0050966]  
1
  • Ortholog Curator
Detection of mechanical stimulus involved in sensory perception of touchdefinition[GO:0050976]  
1
  • Ortholog Curator
Magnesium ion homeostasisdefinition[GO:0010960]  
1
  • UniProtKB
Neuromuscular processdefinition[GO:0050905]  
2
  • UniProtKB
  • Ortholog Curator
Neuronal action potentialdefinition[GO:0019228]  
1
  • Ortholog Curator
Neuronal signal transductiondefinition[GO:0023041]  
1
  • Ortholog Curator
Potassium ion transmembrane transportdefinition[GO:0071805]  
2
  • UniProtKB
  • RefGenome
Potassium ion transportdefinition[GO:0006813]  
1
  • PINC
Protein homooligomerizationdefinition[GO:0051260] silver  
1
  • InterPro 2 GO
Regulation of ion transmembrane transportdefinition[GO:0034765]  
1
  • UniProtKB KW
Regulation of membrane potentialdefinition[GO:0042391]  
1
  • UniProtKB
Regulation of muscle contractiondefinition[GO:0006937]  
1
  • Ortholog Curator
Enzymatic activity 
It is regulated in the following manner
Inhibited by 1.1 mM 4-aminopyridine (4-AP) and by 20mM tetraethylammonium (TEA), but not by charybdotoxin (CTX)(PubMed19912772). Inhibited by dendrotoxin (DTX) (PubMed19307729).  
3
  • UniProtKB
Pathways 
According to Reactome, this protein belongs to the following pathway:
Voltage gated Potassium channels  REACT_75770  
Note 
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).  
2
  • UniProtKB
 

Keywords

Biological process 
Ion transport  definition   [KW-0406]
Potassium transport  definition   [KW-0633]
Transport  definition   [KW-0813]
Molecular function 
Ion channel  definition   [KW-0407]
Potassium channel  definition   [KW-0631]
Voltage-gated channel  definition   [KW-0851]
Technical term 
Reference proteome  definition   [KW-1185]
 

Further external links

Other
GeneWiki: Kv1.1
GenomeRNAi: 3736
PRO: PR:Q09470
Chemistry
GuidetoPHARMACOLOGY: 538