KV7.1 | KVLQT1 | KQT Related Potassium Channel Member 1
Family:
Potassium channels
Subgroups:
Shaker (KV1.1–KV1.8), Shab (KV2.1-KV2.2), Shaw (KV3.1–KV3.4), Shal (KV4.1–KV4.3), KQT like (KV7.1–KV7.5), Eag related (KV10.1-KV10.2), Erg related (KV11.1–KV11.3), Elk related (KV12.1)
Topology:
Contains six transmembrane domains (S1–S6), four single subunits form a pore, homotetramers and heterotetramers are possible.
KV7.1 Background Information
KV7.1, also known as KVLQT1, is a voltage-gated potassium channel present in the cell membranes of cardiac tissue and in inner ear neurons among other tissues. It induces a voltage-dependent by rapidly activating and slowly deactivating potassium-selective outward current and promotes also a delayed voltage activated potassium current showing outward rectification characteristic. In the cardiac cells, KV7.1 mediates the IKs (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. The gene product can form heteromers with KCNE1 (minK), KCNE2, KCNE3 (miRP2), KCNE4, KCNE5 and KCNQ5. General mutations in KV7.1 have been known to cause a decrease in this slow delayed potassium rectifier current, longer cardiac action potentials, and a tendency to have tachyarrhythmias in the heart.
Gene:
KCNQ1
Human Protein:
P51787
Tissue:
Heart, pancreas, inner ear, stomach, colon
Function/ Application:
Contributes to the repolarization of the cardiomyocytes, forms the potassium channel that is important for cyclic AMP-stimulated intestinal secretion of chloride ions and maintains the driving force for proximal tubular and intestinal sodium ions absorption, gastric acid secretion, and cAMP-induced jejunal chloride ions secretion
Pathology:
Beckwith-Wiedemann syndrome, cancer, Long QT syndrome (LQT1, also known as Romano-Ward syndrome), Jervell syndrome, Lange-Nielsen syndrome, Short QT syndrome, Familial Atrial Fibrillation, hyperinsulinemic hypoglycaemia, abnormality of the ear, accelerated skeletal maturation, adrenocortical cytomegaly
Interaction:
Forms heterotetramers with KCNE1 (minK), KCNE2, KCNE3 (miRP2), KCNE4, KCNE5, KCNQ5 and associates with PRKACA, PPP1CA, AKAP9, Serine/threonine-protein kinases SGK, Calmodulin 1, 2, 3
Modulator:
4-AP, bepridil, indapamide 2, Oxotremorine-M, ezogabine, mefenamic acid, E-4031, linopirdine dihydrochloride, agitoxin 2
Assays:
Patch Clamp: whole cell
Recommended Reviews:
Gutman et al. (2005) International Union of Pharmacology. LIII. Nomenclature and molecular relationships of voltage-gated potassium channels. Pharmacol Rev 57(4):473-508