EMD-9112
Cryo-EM map of mechanically activated ion channel OSCA1.2 in nanodisc
EMD-9112
Single-particle3.1 Å
Deposition: 15/09/2018Map released: 14/11/2018
Last modified: 13/03/2024
Sample Organism:
Arabidopsis thaliana
Sample: OSCA1.2
Fitted models: 6mgv (Avg. Q-score: 0.502)
Deposition Authors: Jojoa-Cruz S, Saotome K
Sample: OSCA1.2
Fitted models: 6mgv (Avg. Q-score: 0.502)
Deposition Authors: Jojoa-Cruz S, Saotome K
Cryo-EM structure of the mechanically activated ion channel OSCA1.2.
Jojoa Cruz S ,
Saotome K ,
Murthy SE ,
Tsui CCA ,
Sansom MS ,
Patapoutian A ,
Ward AB
(2018) eLife , 7
,
Saotome K ,
Murthy SE ,
Tsui CCA ,
Sansom MS ,
Patapoutian A ,
Ward AB
(2018) eLife , 7
Abstract:
Mechanically activated ion channels underlie touch, hearing, shear-stress sensing, and response to turgor pressure. OSCA/TMEM63s are a newly-identified family of eukaryotic mechanically activated ion channels opened by membrane tension. The structural underpinnings of OSCA/TMEM63 function are not explored. Here, we elucidate high resolution cryo-electron microscopy structures of OSCA1.2, revealing a dimeric architecture containing eleven transmembrane helices per subunit and surprising topological similarities to TMEM16 proteins. We locate the ion permeation pathway within each subunit by demonstrating that a conserved acidic residue is a determinant of channel conductance. Molecular dynamics simulations reveal membrane interactions, suggesting the role of lipids in OSCA1.2 gating. These results lay a foundation to decipher how the structural organization of OSCA/TMEM63 is suited for their roles as MA ion channels.
Mechanically activated ion channels underlie touch, hearing, shear-stress sensing, and response to turgor pressure. OSCA/TMEM63s are a newly-identified family of eukaryotic mechanically activated ion channels opened by membrane tension. The structural underpinnings of OSCA/TMEM63 function are not explored. Here, we elucidate high resolution cryo-electron microscopy structures of OSCA1.2, revealing a dimeric architecture containing eleven transmembrane helices per subunit and surprising topological similarities to TMEM16 proteins. We locate the ion permeation pathway within each subunit by demonstrating that a conserved acidic residue is a determinant of channel conductance. Molecular dynamics simulations reveal membrane interactions, suggesting the role of lipids in OSCA1.2 gating. These results lay a foundation to decipher how the structural organization of OSCA/TMEM63 is suited for their roles as MA ion channels.