7as6
From Proteopedia
2.0 angstrom structure of plant Extended Synaptotagmin 1, C2A domain
Structural highlights
FunctionSYT1_ARATH Plays an important role in maintaining plasma membrane integrity during freezing and osmotic stresses. May function in membrane resealing during calcium-dependent freezing tolerance. May regulate endocytosis and endosome recycling at the plasma membrane and cell-to-cell trafficking of cabbage leaf curl virus (CaLCuV) and tobacco mosaic virus (TMV) movement proteins via plasmodesmata.[1] [2] [3] [4] [5] Publication Abstract from PubMedNon-vesicular lipid transfer at ER and plasma membrane (PM) contact sites (CS) is crucial for the maintenance of membrane lipid homeostasis. Extended synaptotagmins (E-Syts) play a central role in this process as they act as molecular tethers of ER and PM and as lipid transfer proteins between these organelles. E-Syts are proteins constitutively anchored to the ER through an N-terminal hydrophobic segment and bind the PM via a variable number of C-terminal C2 domains. Synaptotagmins (SYTs) are the plant orthologous of E-Syts and regulate the ER-PM communication in response to abiotic stress. Combining different structural and biochemical techniques, we demonstrate that the binding of SYT1 to lipids occurs through a Ca(2+)-dependent lipid-binding site and by a site for phosphorylated forms of phosphatidylinositol, thus integrating two different molecular signals in response to stress. In addition, we show that SYT1 displays three highly flexible hinge points that provide conformational freedom to facilitate lipid extraction, protein loading, and subsequent transfer between PM and ER. The structure and flexibility analysis of the Arabidopsis synaptotagmin 1 reveal the basis of its regulation at membrane contact sites.,Benavente JL, Siliqi D, Infantes L, Lagartera L, Mills A, Gago F, Ruiz-Lopez N, Botella MA, Sanchez-Barrena MJ, Albert A Life Sci Alliance. 2021 Aug 18;4(10). pii: 4/10/e202101152. doi:, 10.26508/lsa.202101152. Print 2021 Oct. PMID:34408000[6] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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