@article{838c17858a0a42fdb31b7d3dd1047b34,
title = "Structure and activity of SLAC1 channels for stomatal signaling in leaves",
abstract = "Stomata in leaves regulate gas exchange between the plant and its atmosphere. Various environmental stimuli elicit abscisic acid (ABA); ABA leads to phosphoactivation of slow anion channel 1 (SLAC1); SLAC1 activity reduces turgor pressure in aperture-defining guard cells; and stomatal closure ensues. We used electrophysiology for functional characterizations of Arabidopsis thaliana SLAC1 (AtSLAC1) and cryoelectron microscopy (cryo-EM) for structural analysis of Brachypodium distachyon SLAC1 (BdSLAC1), at 2.97-{\AA} resolution. We identified 14 phosphorylation sites in AtSLAC1 and showed nearly 330-fold channel-activity enhancement with 4 to 6 of these phosphorylated. Seven SLAC1-conserved arginines are poised in BdSLAC1 for regulatory interaction with the N-terminal extension. This BdSLAC1 structure has its pores closed, in a basal state, spring loaded by phenylalanyl residues in high-energy conformations. SLAC1 phosphorylation fine-tunes an equilibrium between basal and activated SLAC1 trimers, thereby controlling the degree of stomatal opening.",
keywords = "Abscisic acid signaling, Channel activation, Cryo-EM, Electrophysiology, Phosphorylation",
author = "Deng, {Ya Nan} and Hamdy Kashtoh and Quan Wang and Zhen, {Guang Xiao} and Li, {Qi Yu} and Tang, {Ling Hui} and Gao, {Hai Long} and Zhang, {Chun Rui} and Li Qin and Min Su and Fei Li and Huang, {Xia He} and Wang, {Ying Chun} and Qi Xie and Clarke, {Oliver B.} and Hendrickson, {Wayne A.} and Chen, {Yu Hang}",
note = "Funding Information: ACKNOWLEDGMENTS. We thank Dr. Guang-zhe Yang for suggestions on electrophysiological experiments and De-lin Li, Ling-min Yuan, and other colleagues for expression screening in the early stages of the project. We are also grateful to the staff at the Center for Biological Imaging, Institute of Biophysics, Chinese Academy of Sciences. This project was financially supported by the National Key Research and Development Program of China (Grants 2016YFA0500503 and 2020YFA0509903), the Strategic Priority Research Program of the Chinese Academy of Sciences (Precision Seed Design and Breeding, Grant XDA24020305), and the National Natural Science Foundation of China (Grants 31470728, 31322005, and 31872721) to Y.-h.C., by NIH Grant R35GM134920-01 and NSF Grant MCB-1934628 to F.L., and by NIH Grants R01GM107462 and P41GM116799 to W.A.H. Publisher Copyright: {\textcopyright} 2021 National Academy of Sciences. All rights reserved.",
year = "2021",
month = may,
day = "4",
doi = "10.1073/pnas.2015151118",
language = "English (US)",
volume = "118",
journal = "Proceedings of the National Academy of Sciences of the United States of America",
issn = "0027-8424",
publisher = "National Academy of Sciences",
number = "18",
}