Chloride channel ClC-plant / Chloride channel, voltage gated / Chloride channel, core / Voltage gated chloride channel / CBS domain superfamily / Domain in cystathionine beta-synthase and other proteins. / CBS domain / CBS domain / CBS domain profile. 類似検索 - ドメイン・相同性
National Natural Science Foundation of China (NSFC)
中国
Chinese Academy of Sciences
中国
引用
ジャーナル: Nat Commun / 年: 2023 タイトル: Molecular mechanism underlying regulation of Arabidopsis CLCa transporter by nucleotides and phospholipids. 著者: Zhao Yang / Xue Zhang / Shiwei Ye / Jingtao Zheng / Xiaowei Huang / Fang Yu / Zhenguo Chen / Shiqing Cai / Peng Zhang / 要旨: Chloride channels (CLCs) transport anion across membrane to regulate ion homeostasis and acidification of intracellular organelles, and are divided into anion channels and anion/proton antiporters. ...Chloride channels (CLCs) transport anion across membrane to regulate ion homeostasis and acidification of intracellular organelles, and are divided into anion channels and anion/proton antiporters. Arabidopsis thaliana CLCa (AtCLCa) transporter localizes to the tonoplast which imports NO and to a less extent Cl from cytoplasm. The activity of AtCLCa and many other CLCs is regulated by nucleotides and phospholipids, however, the molecular mechanism remains unclear. Here we determine the cryo-EM structures of AtCLCa bound with NO and Cl, respectively. Both structures are captured in ATP and PI(4,5)P bound conformation. Structural and electrophysiological analyses reveal a previously unidentified N-terminal β-hairpin that is stabilized by ATP binding to block the anion transport pathway, thereby inhibiting the AtCLCa activity. While AMP loses the inhibition capacity due to lack of the β/γ- phosphates required for β-hairpin stabilization. This well explains how AtCLCa senses the ATP/AMP status to regulate the physiological nitrogen-carbon balance. Our data further show that PI(4,5)P or PI(3,5)P binds to the AtCLCa dimer interface and occupies the proton-exit pathway, which may help to understand the inhibition of AtCLCa by phospholipids to facilitate guard cell vacuole acidification and stomatal closure. In a word, our work suggests the regulatory mechanism of AtCLCa by nucleotides and phospholipids under certain physiological scenarios and provides new insights for future study of CLCs.