National Institutes of Health/National Heart, Lung, and Blood Institute (NIH/NHLBI)
R00HL143037
米国
United States - Israel Binational Science Foundation (BSF)
2019159
米国
National Institutes of Health/National Heart, Lung, and Blood Institute (NIH/NHLBI)
R01 HL155398
米国
National Institutes of Health/National Heart, Lung, and Blood Institute (NIH/NHLBI)
R01 HL166628
米国
Swedish Research Council
2022-04305
スウェーデン
Swedish Research Council
no. 2022-06725
スウェーデン
引用
ジャーナル: Cell Res / 年: 2025 タイトル: Mechanisms of KCNQ1 gating modulation by KCNE1/3 for cell-specific function. 著者: Chenxi Cui / Lu Zhao / Ali A Kermani / Shuzong Du / Tanadet Pipatpolkai / Meiqin Jiang / Sagar Chittori / Yong Zi Tan / Jingyi Shi / Lucie Delemotte / Jianmin Cui / Ji Sun / 要旨: KCNQ1 potassium channels are essential for physiological processes such as cardiac rhythm and intestinal chloride secretion. KCNE family subunits (KCNE1-5) associate with KCNQ1, conferring distinct ...KCNQ1 potassium channels are essential for physiological processes such as cardiac rhythm and intestinal chloride secretion. KCNE family subunits (KCNE1-5) associate with KCNQ1, conferring distinct properties across various tissues. KCNQ1 activation requires membrane depolarization and phosphatidylinositol 4,5-bisphosphate (PIP2) whose cellular levels are controlled by Gαq-coupled GPCR activation. While modulation of KCNQ1's voltage-dependent activation by KCNE1/3 is well-characterized, their effects on PIP2-dependent gating of KCNQ1 via GPCR signaling remain less understood. Here we resolved structures of KCNQ1-KCNE1 and reassessed the reported KCNQ1-KCNE3 structures with and without PIP2. We revealed that KCNQ1-KCNE1/3 complexes feature two PIP2-binding sites, with KCNE1/3 contributing to a previously overlooked, uncharacterized site involving residues critical for coupling voltage sensor and pore domains. Via this site, KCNE1 and KCNE3 distinctly modulate the PIP2-dependent gating, in addition to the voltage sensitivity, of KCNQ1. Consequently, KCNE3 converts KCNQ1 into a voltage-insensitive PIP2-gated channel governed by GPCR signaling to maintain ion homeostasis in non-excitable cells. KCNE1, by significantly enhancing KCNQ1's PIP2 affinity and resistance to GPCR regulation, forms predominantly voltage-gated channels with KCNQ1 for conducting the slow-delayed rectifier current in excitable cardiac cells. Our study highlights how KCNE1/3 modulates KCNQ1 gating in different cellular contexts, providing insights into tissue-specifically targeting multi-functional channels.