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
Members of the OSCA/TMEM63 family are mechanically activated ion channels and structures of some OSCA members have revealed the architecture of these channels and structural features that are potentially involved in mechanosensation. However, these structures are all in a similar state and information about the motion of different elements of the structure is limited, preventing a deeper understanding of how these channels work. Here, we used cryoelectron microscopy to determine high-resolution structures of Arabidopsis thaliana OSCA1.2 and OSCA2.3 in peptidiscs. The structure of OSCA1.2 matches previous structures of the same protein in different environments. Yet, in OSCA2.3, the TM6a-TM7 linker adopts a different conformation that constricts the pore on its cytoplasmic side. Furthermore, coevolutionary sequence analysis uncovered a conserved interaction between the TM6a-TM7 linker and the beam-like domain (BLD). Our results reveal conformational heterogeneity and differences in conserved interactions between the TMD and BLD among members of the OSCA family.
Structure of mechanically activated ion channel OSCA2.3 reveals mobile elements in the transmembrane domain.,Jojoa-Cruz S, Burendei B, Lee WH, Ward AB Structure. 2023 Dec 6:S0969-2126(23)00411-2. doi: 10.1016/j.str.2023.11.009. PMID:38103547[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, Burendei B, Lee WH, Ward AB. Structure of mechanically activated ion channel OSCA2.3 reveals mobile elements in the transmembrane domain. Structure. 2023 Dec 6:S0969-2126(23)00411-2. PMID:38103547 doi:10.1016/j.str.2023.11.009