6ijz
From Proteopedia
Structure of a plant cation channel
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 PubMedIn plants, hyperosmolality stimuli triggers opening of the osmosensitive channels, leading to a rapid downstream signaling cascade initiated by cytosolic calcium concentration elevation. Members of the OSCA family in Arabidopsis thaliana, identified as the hyperosmolality-gated calcium-permeable channels, have been suggested to play a key role during the initial phase of hyperosmotic stress response. Here, we report the atomic structure of Arabidopsis OSCA1.2 determined by single-particle cryo-electron microscopy. It contains 11 transmembrane helices and forms a homodimer. It is in an inactivated state, and the pore-lining residues are clearly identified. Its cytosolic domain contains a RNA recognition motif and two unique long helices. The linker between these two helices forms an anchor in the lipid bilayer and may be essential to osmosensing. The structure of AtOSCA1.2 serves as a platform for the study of the mechanism underlying osmotic stress responses and mechanosensing. Structure of the hyperosmolality-gated calcium-permeable channel OSCA1.2.,Liu X, Wang J, Sun L Nat Commun. 2018 Nov 29;9(1):5060. doi: 10.1038/s41467-018-07564-5. PMID:30498218[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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Categories: Large Structures | Liu, X | Sun, L | Wang, J | Channel | Membrane protein