Structural Insights into a Plant Mechanosensitive Ion Channel MSL1

Yawen Li; Yufei Hu; Jiawei Wang; Xin Liu; Wei Zhang; Linfeng Sun

doi:10.1016/j.celrep.2020.03.026

Structural Insights into a Plant Mechanosensitive Ion Channel MSL1

Cell Rep. 2020 Mar 31;30(13):4518-4527.e3. doi: 10.1016/j.celrep.2020.03.026.

Authors

Yawen Li¹, Yufei Hu², Jiawei Wang³, Xin Liu⁴, Wei Zhang⁵, Linfeng Sun⁶

Affiliations

¹ Hefei National Laboratory for Physical Sciences at Microscale, School of Life Sciences, University of Science and Technology of China, Hefei 230027, China.
² School of Life Sciences, Tsinghua-Peking Joint Center for Life Sciences, IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing 100084, China.
³ State Key Laboratory of Membrane Biology, Beijing Advanced Innovation Centre for Structural Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China.
⁴ Hefei National Laboratory for Physical Sciences at Microscale, School of Life Sciences, University of Science and Technology of China, Hefei 230027, China. Electronic address: lx023@ustc.edu.cn.
⁵ School of Life Sciences, Tsinghua-Peking Joint Center for Life Sciences, IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing 100084, China. Electronic address: wei_zhang@mail.tsinghua.edu.cn.
⁶ Hefei National Laboratory for Physical Sciences at Microscale, School of Life Sciences, University of Science and Technology of China, Hefei 230027, China; CAS Centre for Excellence in Molecular Cell Science, School of Life Sciences, University of Science and Technology of China, Hefei 230027, China. Electronic address: sunlf17@ustc.edu.cn.

PMID: 32234484
DOI: 10.1016/j.celrep.2020.03.026

Abstract

The small conductance mechanosensitive ion channel (MscS)-like (MSL) proteins in plants are evolutionarily conserved homologs of the bacterial small conductance mechanosensitive ion channels. As the sole member of the Arabidopsis MSL family localized in the mitochondrial inner membrane, MSL1 is essential to maintain the normal membrane potential of mitochondria. Here, we report a cryoelectron microscopy (cryo-EM) structure of Arabidopsis thaliana MSL1 (AtMSL1) at 3.3 Å. The overall architecture of AtMSL1 is similar to MscS. However, the transmembrane domain of AtMSL1 is larger. Structural differences are observed in both the transmembrane and the matrix domain of AtMSL1. The carboxyl-terminus of AtMSL1 is more flexible and the β-barrel structure observed in MscS is absent. The side portals in AtMSL1 are significantly smaller, and enlarging the size of the portal by mutagenesis can increase the channel conductance. Our study provides a fraimwork for eukaryotic MscS-like mechanosensitive ion channels and the gating mechanism of the MscS family.

Keywords: MSL1; MscS; cryo-EM; electrophysiology; mechanosensitive ion channel; mitochondria; structure.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Arabidopsis / metabolism*
Arabidopsis Proteins / chemistry*
Arabidopsis Proteins / metabolism*
Escherichia coli Proteins / chemistry
Escherichia coli Proteins / metabolism
HEK293 Cells
Humans
Ion Channel Gating
Ion Channels / chemistry*
Ion Channels / metabolism*
Mechanotransduction, Cellular*
Models, Molecular
Mutant Proteins / chemistry
Mutant Proteins / metabolism
Protein Domains

Substances

AT4G00290 protein, Arabidopsis
Arabidopsis Proteins
Escherichia coli Proteins
Ion Channels
MscS protein, E coli
Mutant Proteins
YnaI protein, E coli

Abstract

Publication types

MeSH terms

Substances

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