National Institutes of Health/National Eye Institute (NIH/NEI)
RO1EY027800
米国
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)
R01GM085234
米国
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)
R01GM055440
米国
National Natural Science Foundation of China (NSFC)
21625302
中国
National Natural Science Foundation of China (NSFC)
21573217
中国
National Natural Science Foundation of China (NSFC)
31700647
中国
引用
ジャーナル: Nat Struct Mol Biol / 年: 2020 タイトル: Mechanism of ligand activation of a eukaryotic cyclic nucleotide-gated channel. 著者: Xiangdong Zheng / Ziao Fu / Deyuan Su / Yuebin Zhang / Minghui Li / Yaping Pan / Huan Li / Shufang Li / Robert A Grassucci / Zhenning Ren / Zhengshan Hu / Xueming Li / Ming Zhou / Guohui Li / ...著者: Xiangdong Zheng / Ziao Fu / Deyuan Su / Yuebin Zhang / Minghui Li / Yaping Pan / Huan Li / Shufang Li / Robert A Grassucci / Zhenning Ren / Zhengshan Hu / Xueming Li / Ming Zhou / Guohui Li / Joachim Frank / Jian Yang / 要旨: Cyclic nucleotide-gated (CNG) channels convert cyclic nucleotide (CN) binding and unbinding into electrical signals in sensory receptors and neurons. The molecular conformational changes underpinning ...Cyclic nucleotide-gated (CNG) channels convert cyclic nucleotide (CN) binding and unbinding into electrical signals in sensory receptors and neurons. The molecular conformational changes underpinning ligand activation are largely undefined. We report both closed- and open-state atomic cryo-EM structures of a full-length Caenorhabditis elegans cyclic GMP-activated channel TAX-4, reconstituted in lipid nanodiscs. These structures, together with computational and functional analyses and a mutant channel structure, reveal a double-barrier hydrophobic gate formed by two S6 amino acids in the central cavity. cGMP binding produces global conformational changes that open the cavity gate located ~52 Å away but do not alter the structure of the selectivity filter-the commonly presumed activation gate. Our work provides mechanistic insights into the allosteric gating and regulation of CN-gated and nucleotide-modulated channels and CNG channel-related channelopathies.