KvLQT1

K_v7.1 (KvLQT1) is a potassium channel protein whose primary subunit in humans is encoded by the KCNQ1 gene. 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.

Structure

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.

Function

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. 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.