potassium voltage-gated channel, KQT-like subfamily, member 1
|Alt. Symbols||LQT, KCNA9, Kv7.1|
|Locus||Chr. 11 p15.5|
KvLQT1 (Kv7.1) is a potassium channel protein coded for by the gene KCNQ1. KvLQT1 is present in the cell membranes of cardiac muscle tissue and in inner ear neurons among other tissues. In the cardiac cells, KvLQT1 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.
Mutations in the gene can lead to a defective protein and several forms of inherited arrhythmias as Long QT syndrome, Short QT syndrome, and Familial Atrial Fibrillation. Currents arising from KvLQT1 in over-expression systems have never been recapitulated in native tissues - KvLQT1 is always found in native tissues with a modulatory subunit. In cardiac tissue, these subunits comprise KCNE1 and yotiao. Though physiologically irrelevant, homotetrameric KvLQT1 channels also display a unique form of N-type inactivation that reaches quilibrium quickly, allowing KvLQT1 currents to plateau. This is different from the inactivation seen in A-type currents, in which most of the current never returns.