Contents

KCNA4

Protein-coding gene in the species Homo sapiens

KCNA4
Identifiers
Aliases	KCNA4, HBK4, HK1, HPCN2, HUKII, KCNA4L, KCNA8, KV1.4, PCN2, potassium voltage-gated channel subfamily A member 4, MCIDDS
External IDs	OMIM: 176266; MGI: 96661; HomoloGene: 20514; GeneCards: KCNA4; OMA:KCNA4 - orthologs
Gene location (Human) Chr. Chromosome 11 (human)[1] Band 11p14.1 Start 30,009,730 bp[1] End 30,017,030 bp[1]
Gene location (Mouse) Chr. Chromosome 2 (mouse)[2] Band 2 E3|2 56.12 cM Start 107,120,984 bp[2] End 107,128,847 bp[2]
RNA expression pattern Bgee Human Mouse (ortholog) Top expressed in nucleus accumbens secondary oocyte caudate nucleus left adrenal cortex putamen prefrontal cortex right adrenal gland right adrenal cortex ventricular zone paraflocculus of cerebellum Top expressed in nucleus accumbens lumbar spinal ganglion medial geniculate nucleus medial dorsal nucleus lateral geniculate nucleus olfactory tubercle substantia nigra globus pallidus mammillary body supraoptic nucleus More reference expression data BioGPS More reference expression data
Gene ontology Molecular function potassium channel activity potassium ion binding voltage-gated ion channel activity ion channel activity protein binding voltage-gated potassium channel activity delayed rectifier potassium channel activity Cellular component integral component of membrane cell projection membrane voltage-gated potassium channel complex plasma membrane axon integral component of plasma membrane dendritic spine Biological process regulation of ion transmembrane transport ion transport potassium ion transport transmembrane transport potassium ion transmembrane transport protein homooligomerization Sources:Amigo / QuickGO
Orthologs Species Human Mouse Entrez 3739 16492 Ensembl ENSG00000182255 ENSMUSG00000042604 UniProt P22459 Q61423 RefSeq (mRNA) NM_002233 NM_021275 RefSeq (protein) NP_002224 NP_067250 Location (UCSC) Chr 11: 30.01 – 30.02 Mb Chr 2: 107.12 – 107.13 Mb PubMed search [3] [4]
Wikidata
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Potassium channel Kv1.4 tandem inactivation domain
solution structure of the tandem inactivation domain (residues 1-75) of potassium channel rck4 (kv1.4)
Identifiers
Symbol	K_channel_TID
Pfam	PF07941
InterPro	IPR012897
SCOP2	1kn7 / SCOPe / SUPFAM
Available protein structures: Pfam   structures / ECOD   PDB RCSB PDB; PDBe; PDBj PDBsum structure summary

Potassium voltage-gated channel subfamily A member 4 also known as K_v1.4 is a protein that in humans is encoded by the KCNA4 gene.^[5][6][7] It contributes to the cardiac transient outward potassium current (I_to1), the main contributing current to the repolarizing phase 1 of the cardiac action potential.^[8]

Description[edit]

Potassium channels represent the most complex class of voltage-gated ion channels from both functional and structural standpoints. Their diverse functions include regulating neurotransmitter release, heart rate, insulin secretion, neuronal excitability, epithelial electrolyte transport, smooth muscle contraction, and cell volume. Four sequence-related potassium channel genes - shaker, shaw, shab, and shal - have been identified in Drosophila, and each has been shown to have human homolog(s). This gene encodes a member of the potassium channel, voltage-gated, shaker-related subfamily. This member contains six membrane-spanning domains with a shaker-type repeat in the fourth segment. It belongs to the A-type potassium current class, the members of which may be important in the regulation of the fast repolarizing phase of action potentials in heart and thus may influence the duration of cardiac action potential. The coding region of this gene is intronless, and the gene is clustered with genes KCNA3 and KCNA10 on chromosome 1 in humans.^[7]

KCNA4 (Kv1.4) contains a tandem inactivation domain at the N terminus. It is composed of two subdomains. Inactivation domain 1 (ID1, residues 1-38) consists of a flexible N terminus anchored at a 5-turn helix, and is thought to work by occluding the ion pathway, as is the case with a classical ball domain. Inactivation domain 2 (ID2, residues 40-50) is a 2.5 turn helix with a high proportion of hydrophobic residues that probably serves to attach ID1 to the cytoplasmic face of the channel. In this way, it can promote rapid access of ID1 to the receptor site in the open channel. ID1 and ID2 function together to bring about fast inactivation of the Kv1.4 channel, which is important for the role of the channel in short-term plasticity.^[9]

Interactions[edit]

KCNA4 has been shown to interact with DLG4,^{[10][11][12][13]} KCNA2^[14] and DLG1.^[10][12][15]

See also[edit]

• Voltage-gated potassium channel
• Voltage-gated potassium-channel Kv1.4 IRES

References[edit]

Further reading[edit]

External links[edit]

• Kv1.4+Potassium+Channel at the U.S. National Library of Medicine Medical Subject Headings (MeSH)
• KCNA4+protein,+human at the U.S. National Library of Medicine Medical Subject Headings (MeSH)
• Overview of all the structural information available in the PDB for UniProt: P15385 (Rat Potassium voltage-gated channel subfamily A member 4) at the PDBe-KB.

This article incorporates text from the United States National Library of Medicine, which is in the public domain.