6V01

structure of human KCNQ1-KCNE3-CaM complex with PIP2

6V01 の概要

• エントリーDOI: 10.2210/pdb6v01/pdb
• EMDBエントリー: 20967
• 分子名称: Calmodulin-1, Potassium voltage-gated channel subfamily E member 3, Potassium voltage-gated channel subfamily KQT member 1, ... (5 entities in total)
• 機能のキーワード: potassium channel, kcnq1, cam, membrane protein
• 由来する生物種: Homo sapiens (Human); 詳細
• タンパク質・核酸の鎖数: 12
• 化学式量合計: 371855.05

構造登録者

Mackinnon, R.,Sun, J. (登録日: 2019-11-18, 公開日: 2019-12-04, 最終更新日: 2025-06-04)

主引用文献

Sun, J.,MacKinnon, R.
Structural Basis of Human KCNQ1 Modulation and Gating.
Cell, 180:340-347.e9, 2020

PubMed Abstract: KCNQ1, also known as Kv7.1, is a voltage-dependent K channel that regulates gastric acid secretion, salt and glucose homeostasis, and heart rhythm. Its functional properties are regulated in a tissue-specific manner through co-assembly with beta subunits KCNE1-5. In non-excitable cells, KCNQ1 forms a complex with KCNE3, which suppresses channel closure at negative membrane voltages that otherwise would close it. Pore opening is regulated by the signaling lipid PIP2. Using cryoelectron microscopy (cryo-EM), we show that KCNE3 tucks its single-membrane-spanning helix against KCNQ1, at a location that appears to lock the voltage sensor in its depolarized conformation. Without PIP2, the pore remains closed. Upon addition, PIP2 occupies a site on KCNQ1 within the inner membrane leaflet, which triggers a large conformational change that leads to dilation of the pore's gate. It is likely that this mechanism of PIP2 activation is conserved among Kv7 channels.

PubMed: 31883792
DOI: 10.1016/j.cell.2019.12.003

実験手法

ELECTRON MICROSCOPY (3.9 Å)