1.A.17.5.19
OSCA1.2 of 772 aas and 11 TMSs.  It is a dimer containing eleven TMSs per subunit, similar to other TMEM16 proteins. Jojoa Cruz et al. 2018 located the ion permeation pathway within each subunit by demonstrating that a conserved acidic residue is a determinant of channel conductance. Molecular dynamics simulations revealed membrane interactions, suggesting a role of lipids in gating.  The high resolution structure of this hyperosmolality-gated calcium-permeable channel has been determined (Liu et al. 2018). It contains 11 TMSs and forms a homodimer. The pore-lining residues were clearly identified. Its cytosolic domain contains an 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. Genome-wide analyses of OSCA gene family members in Vigna radiata have revealed their involvement in the osmotic response (Yin et al. 2021). There are 42 OSCA channel proteins in Triticum aestivum, and  their diverse roles during development and stress responses have been evaluated (Kaur et al. 2022).