KCNE4
Description
The KCNE4 (potassium voltage-gated channel subfamily E regulatory subunit 4) is a protein-coding gene located on chromosome 2.
KCNE4 is a protein encoded by the KCNE4 gene in humans. It is a member of the KCNE family of voltage-gated potassium (Kv) channel ancillary or β subunits, and is involved in regulating potassium channel function. KCNE4 is best known for modulating the KCNQ1 Kv α subunit, but it also regulates KCNQ4, Kv1.x, Kv2.1, Kv4.x and BK α subunits. KCNE4 often acts as an inhibitory subunit, suppressing potassium channel function, but this varies depending on the channel subtype. KCNE4 strongly inhibits the KCNQ1 potassium channel, which is important for human cardiac myocyte repolarization and in multiple epithelial cell types. This inhibition requires calmodulin, which binds to both KCNQ1 and KCNE4. KCNE4 can also inhibit complexes formed by KCNQ1 and KCNE1. KCNE4 has no effect on KCNQ2, KCNQ3 or KCNQ5 channels, but augments activity of KCNQ4 in HEK cells, mesenteric artery and Xenopus laevis oocytes.
KCNE4 is an ancillary protein that forms a complex with voltage-gated potassium channels. It functions as a beta subunit, modulating the gating kinetics and enhancing the stability of the channel complex. KCNE4 associates with KCNQ1/KVLTQ1 and inhibits potassium currents.
KCNE4 is also known as MIRP3.
