9J34

Cryo-EM structure of Arabidopsis CNGC1

9J34 の概要

• エントリーDOI: 10.2210/pdb9j34/pdb
• EMDBエントリー: 61105
• 分子名称: Cyclic nucleotide-gated ion channel 1, CALCIUM ION (3 entities in total)
• 機能のキーワード: cryo-em, membrane protein, polymer, plant protein
• 由来する生物種: Arabidopsis thaliana (thale cress)
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 332932.80

構造登録者

Wang, J.P.,Zhang, P.,Zhang, X. (登録日: 2024-08-07, 公開日: 2025-02-19, 最終更新日: 2025-04-02)

主引用文献

Wang, J.,Du, B.Y.,Zhang, X.,Qu, X.,Yang, Y.,Yang, Z.,Wang, Y.F.,Zhang, P.
Cryo-EM structures of Arabidopsis CNGC1 and CNGC5 reveal molecular mechanisms underlying gating and calcium selectivity.
Nat.Plants, 11:632-642, 2025

PubMed Abstract: Plant cyclic nucleotide-gated channels (CNGCs) belong to the cyclic nucleotide-binding domain (CNBD) channel family, but are phylogenetically classified in a distinct branch. In contrast to their animal counterparts of K-selective or non-selective cation channels, plant CNGCs mainly mediate Ca influx and are involved in various physiological processes, such as stomatal movements, pollen-tube growth and immune responses. Here, we present the cryo-EM structure and electrophysiological analysis of plant CNGC representatives, Arabidopsis CNGC1 and CNGC5. We found that CNGC1 and CNGC5 contain a unique extracellular domain featuring disulfide bonds that is essential for channel gating via coupling of the voltage-sensing domain with the pore domain. The pore domain selectivity filter possesses a Gln residue at the constriction site that determines the Ca selectivity. Replacement of this Gln with Glu, typically observed in CNBD-type non-selective cation channels, could convert CNGC1 and CNGC5 from Ca-selective channels to non-selective cation channels permeable to Ca, Na or K. In addition, we found that the CNGC1 and CNGC5 CNBD homology domain contains intrinsic-ligand-like interactions, which may devoid the binding of cyclic nucleotides and lead to gating independent of cAMP or cGMP. This research not only provides a mechanistic understanding of plant CNGCs' function, but also adds to the comprehensive knowledge of the CNBD channels.

PubMed: 39979428
DOI: 10.1038/s41477-025-01923-z

実験手法

ELECTRON MICROSCOPY (2.51 Å)