Kv LQT1

Kv LQT1

Identifiers Symbols KCNQ1; ATFB1; ATFB3; JLNS1; KCNA8; KCNA9; KVLQT1; Kv1.9; Kv7.1; LQT; LQT1; RWS; SQT2; WRS External IDs OMIM: 607542 MGI: 108083 HomoloGene: 85014 IUPHAR: K_v7.1 ChEMBL: 1866 GeneCards: KCNQ1 Gene

Gene Ontology
Molecular function	• voltage-gated potassium channel activity • delayed rectifier potassium channel activity • calmodulin binding • outward rectifier potassium channel activity
Cellular component	• lysosome • early endosome • late endosome • plasma membrane • voltage-gated potassium channel complex • basolateral plasma membrane • sarcolemma • zymogen granule membrane
Biological process	• regulation of gene expression by genetic imprinting • muscle contraction • synaptic transmission • sensory perception of sound • blood circulation • regulation of heart contraction • gene silencing • response to chemical stimulus • negative regulation of insulin secretion • regulation of membrane repolarization • potassium ion export
Sources: Amigo / QuickGO

RNA expression pattern More reference expression data Orthologs Species Human Mouse Entrez 3784 16535 Ensembl ENSG00000053918 ENSMUSG00000009545 UniProt P51787 P97414 RefSeq (mRNA) NM_000218.2 NM_008434.2 RefSeq (protein) NP_000209.2 NP_032460.2 Location (UCSC) Chr 11:
2.47 – 2.87 Mb Chr 7:
143.11 – 143.43 Mb PubMed search

K_v7.1 (KvLQT1) is a potassium channel protein coded for by the gene KCNQ1. K_v7.1 is a voltage-gated potassium channel present in the cell membranes of cardiac tissue and in inner ear neurons among other tissues. In the cardiac cells, K_v7.1 mediates the I_Ks (or slow delayed rectifying K+) current that contributes to the repolarization of the cell, terminating the cardiac action potential and thereby the heart's contraction. Structurally, KvLQT1 is made of six membrane-spanning domains S1-S6, two intracellular domains, and a pore loop. The KvLQT1 channel is made of four KCNQ1 subunits, which form the actual ion channel.

Mutations in the gene can lead to a defective protein and several forms of inherited arrhythmias as Long QT syndrome which is a prolongation of the QT interval of heart repolarization, Short QT syndrome, and Familial Atrial Fibrillation. Currents arising from K_v7.1 in over-expression systems have never been recapitulated in native tissues - K_v7.1 is always found in native tissues with a modulatory subunit. In cardiac tissue, these subunits comprise KCNE1 and yotiao. Though physiologically irrelevant, homotetrameric K_v7.1 channels also display a unique form of C-type inactivation that reaches equilibrium quickly, allowing KvLQT1 currents to plateau. This is different from the inactivation seen in A-type currents, which causes rapid current decay.

This gene encodes a protein for a voltage-gated potassium channel required for the repolarization phase of the cardiac action potential. The gene product can form heteromultimers with two other potassium channel proteins, KCNE1 and KCNE3. Mutations in this gene are associated with hereditary long QT syndrome, especially mutations Y111C or L114P. Romano-Ward syndrome, Jervell and Lange-Nielsen syndrome and familial atrial fibrillation can also result from mutations in the KCNQ1 gene. The gene is located in a region of chromosome 11 that contains a large number of contiguous genes that are abnormally imprinted in cancer and the Beckwith-Wiedemann syndrome. Two alternative transcripts encoding distinct isoforms have been described.