Structural highlights
Function
[CSC1_ARATH] Acts as an osmosensitive calcium-permeable cation channel. Specifically conducts cations including Ca(2+), K(+) and Na(+) in vitro. Inactivation or closure of the channel is calcium-dependent.[1]
Publication Abstract from PubMed
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.
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 Elife. 2018 Nov 1;7. pii: 41845. doi: 10.7554/eLife.41845. PMID:30382939[2]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Hou C, Tian W, Kleist T, He K, Garcia V, Bai F, Hao Y, Luan S, Li L. DUF221 proteins are a family of osmosensitive calcium-permeable cation channels conserved across eukaryotes. Cell Res. 2014 May;24(5):632-5. doi: 10.1038/cr.2014.14. Epub 2014 Feb 7. PMID:24503647 doi:http://dx.doi.org/10.1038/cr.2014.14
- ↑ Jojoa Cruz S, Saotome K, Murthy SE, Tsui CCA, Sansom MS, Patapoutian A, Ward AB. Cryo-EM structure of the mechanically activated ion channel OSCA1.2. Elife. 2018 Nov 1;7. pii: 41845. doi: 10.7554/eLife.41845. PMID:30382939 doi:http://dx.doi.org/10.7554/eLife.41845
