Potassium voltage-gated channel subfamily E regulatory subunit 3 (KCNE3)

Potassium voltage-gated channel subfamily E regulatory subunit 3 (KCNE3) is a type I membrane protein that functions as a regulatory (beta) subunit for several voltage-gated potassium (Kv) channels, most notably KCNQ1 (Kv7.1)[1][2][5][6]. KCNE3 alters the gating kinetics, trafficking, and current properties of its partner channels, converting the otherwise voltage-dependent KCNQ1 channel into a constitutively open (voltage-independent) potassium (K+) channel, critical for potassium ion recycling and transepithelial chloride secretion in various epithelial tissues, including the intestines and airways[1][2][5]. KCNE3 is expressed in several tissues and can modulate additional Kv channels such as KCNQ4, hERG, Kv2.1, and Kv3.x subfamilies. Genetic variants in KCNE3 are implicated in cardiac arrhythmias, cystic fibrosis severity modulation, and periodic paralysis[4][5][6]. KCNE3 does not form ion channels on its own but exerts profound effects on potassium channel activity through subunit assembly and direct physical interactions with voltage sensor domains of the channel alpha subunits.

Other names

Potassium voltage-gated channel subfamily E member 3MiRP2MinK-related peptide 2Minimum potassium ion channel-related peptide 2Potassium channel subunit beta MiRP2HOKPPBRGDA6HYPPcardiac voltage-gated potassium channel accessory subunitIsk-related family member 3voltage-gated K+ channel subunit MiRP2

Modulation of voltage-gated potassium channel gating kinetics - Stabilization of the activated state of KCNQ1 and related channels - Conversion of KCNQ1 from voltage-dependent to constitutively open state[5][3][1]