8XW1 | pdb_00008xw1

Cryo-EM structure of OSCA1.2-V335W-DDM state

• PDB DOI: https://doi.org/10.2210/pdb8XW1/pdb
• EM Map EMD-38727: EMDB EMDataResource

• Classification: PLANT PROTEIN
• Organism(s): Arabidopsis thaliana
• Expression System: Homo sapiens
• Mutation(s): Yes 
• Membrane Protein: Yes  PDBTMmpstruc


• Deposited: 2024-01-15 Released: 2024-04-10 
• Deposition Author(s): Zhang, Y., Han, Y.
• Funding Organization(s): Ministry of Science and Technology (MoST, China), Australian Research Council (ARC)

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Experimental Data Snapshot

• Method: ELECTRON MICROSCOPY
• Resolution: 4.49 Å
• Aggregation State: PARTICLE 
• Reconstruction Method: SINGLE PARTICLE 

Literature

Mechanical activation opens a lipid-lined pore in OSCA ion channels.

Han, Y., Zhou, Z., Jin, R., Dai, F., Ge, Y., Ju, X., Ma, X., He, S., Yuan, L., Wang, Y., Yang, W., Yue, X., Chen, Z., Sun, Y., Corry, B., Cox, C.D., Zhang, Y.

(2024) Nature 628: 910-918

• PubMed: 38570680 
• DOI: https://doi.org/10.1038/s41586-024-07256-9
• Primary Citation Related Structures: 
  8XAJ, 8XNG, 8XRY, 8XS0, 8XS4, 8XS5, 8XVX, 8XVY, 8XVZ, 8XW0, 8XW1, 8XW2, 8XW3, 8XW4


• PubMed Abstract: 
  

  OSCA/TMEM63 channels are the largest known family of mechanosensitive channels ^1-3 , playing critical roles in plant ^4-7 and mammalian ^8,9 mechanotransduction. Here we determined 44 cryogenic electron microscopy structures of OSCA/TMEM63 channels in different environments to investigate the molecular basis of OSCA/TMEM63 channel mechanosensitivity. In nanodiscs, we mimicked increased membrane tension and observed a dilated pore with membrane access in one of the OSCA1.2 subunits. In liposomes, we captured the fully open structure of OSCA1.2 in the inside-in orientation, in which the pore shows a large lateral opening to the membrane. Unusually for ion channels, structural, functional and computational evidence supports the existence of a 'proteo-lipidic pore' in which lipids act as a wall of the ion permeation pathway. In the less tension-sensitive homologue OSCA3.1, we identified an 'interlocking' lipid tightly bound in the central cleft, keeping the channel closed. Mutation of the lipid-coordinating residues induced OSCA3.1 activation, revealing a conserved open conformation of OSCA channels. Our structures provide a global picture of the OSCA channel gating cycle, uncover the importance of bound lipids and show that each subunit can open independently. This expands both our understanding of channel-mediated mechanotransduction and channel pore formation, with important mechanistic implications for the TMEM16 and TMC protein families.

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Organizational Affiliation: 
• Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, China.
Shanghai Key Laboratory of Aging Studies, Shanghai, China.
Molecular Cardiology and Biophysics Division, Victor Chang Cardiac Research Institute, Sydney, New South Wales, Australia.
School of Clinical Medicine, Faculty of Medicine and Health, University of New South Wales, Sydney, New South Wales, Australia.
Research School of Biology, Australian National University, Acton, Australian Capital Territory, Australia.
School of Life Science and Technology, ShanghaiTech University, Shanghai, China.
Department of Biophysics, and Department of Neurology of the Fourth Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.
Research School of Biology, Australian National University, Acton, Australian Capital Territory, Australia. [e-mail].
Molecular Cardiology and Biophysics Division, Victor Chang Cardiac Research Institute, Sydney, New South Wales, Australia. [e-mail].
School of Biomedical Sciences, Faculty of Medicine, University of New South Wales, Sydney, New South Wales, Australia. [e-mail].
Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, China. [e-mail].
Shanghai Key Laboratory of Aging Studies, Shanghai, China. [e-mail].
State Key Laboratory of Chemical Biology, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, China. [e-mail].

Biological Assembly 1  

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Monomer - A1 

Biological assembly 1 assigned by authors.

Biological Assembly Evidence: electron microscopy

Macromolecule Content 

• Total Structure Weight: 88.7 kDa 
• Atom Count: 5,082 
• Modeled Residue Count: 634 
• Deposited Residue Count: 777 
• Unique protein chains: 1

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Calcium permeable stress-gated cation channel 1	A	777	Arabidopsis thaliana	Mutation(s): 1  Gene Names: CSC1, OSCA1.2, At4g22120, F1N20.220 Membrane Entity: Yes
UniProt
Find proteins for Q5XEZ5 (Arabidopsis thaliana) Explore Q5XEZ5  Go to UniProtKB:  Q5XEZ5

Experimental Data & Validation

Experimental Data

• Method: ELECTRON MICROSCOPY
• Resolution: 4.49 Å
• Aggregation State: PARTICLE 
• Reconstruction Method: SINGLE PARTICLE 

EM Software:

Task	Software Package	Version
MODEL REFINEMENT	PHENIX

Structure Validation

Entry History 

& Funding Information

Deposition Data

• Released Date: 2024-04-10 
Deposition Author(s): Zhang, Y., Han, Y.

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Funding Organization	Location	Grant Number
Ministry of Science and Technology (MoST, China)	China	2022ZD0207400
Australian Research Council (ARC)	Australia	FT220100159
Australian Research Council (ARC)	Australia	DP200100860

Revision History  

• Version 1.0: 2024-04-10
  Type: Initial release
  
• Version 1.1: 2024-04-17
  Changes: Database references
• Version 1.2: 2024-05-08
  Changes: Database references
• Version 1.3: 2025-07-02
  Changes: Data collection, Structure summary