PT  - JOURNAL ARTICLE
AU  - Noemi Ruiz-Lopez
AU  - Jessica Pérez-Sancho
AU  - Alicia Esteban del Valle
AU  - Richard P. Haslam
AU  - Steffen Vanneste
AU  - Rafael Catalá
AU  - Carlos Perea-Resa
AU  - Daniël Van Damme
AU  - Selene García-Hernández
AU  - Armando Albert
AU  - José Vallarino
AU  - Jinxing Lin
AU  - Jir□í Friml
AU  - Alberto P. Macho
AU  - Julio Salinas
AU  - Abel Rosado
AU  - Johnathan A. Napier
AU  - Vitor Amorim-Silva
AU  - Miguel A. Botella
TI  - Synaptotagmins Maintain Diacylglycerol Homeostasis at Endoplasmic Reticulum-Plasma Membrane Contact Sites during Abiotic Stress
AID  - 10.1101/2020.07.28.222919
DP  - 2020 Jan 01
TA  - bioRxiv
PG  - 2020.07.28.222919
4099  - http://biorxiv.org/content/early/2020/07/29/2020.07.28.222919.short
4100  - http://biorxiv.org/content/early/2020/07/29/2020.07.28.222919.full
AB  - Endoplasmic Reticulum-Plasma Membrane contact sites (ER-PM CS) play fundamental roles in all eukaryotic cells. Arabidopsis mutants lacking the ER-PM protein tether synaptotagmin1 (SYT1) exhibit decreased plasma membrane (PM) integrity under multiple abiotic stresses such as freezing, high salt, osmotic stress and mechanical damage. Here, we show that, together with SYT1, the stress-induced SYT3 is an ER-PM tether that also functions in maintaining PM integrity. The ER-PM CS localization of SYT1 and SYT3 is dependent on PM phosphatidylinositol-4-phosphate and is regulated by abiotic stress. Lipidomic analysis revealed that cold stress increased the accumulation of diacylglycerol at the PM in a syt1/3 double mutant relative to WT while the levels of most glycerolipid species remain unchanged. Additionally, SYT1-GFP preferentially binds diacylglycerol in vivo with little affinity for polar glycerolipids. Our work uncovers a crucial SYT-dependent mechanism of stress adaptation counteracting the detrimental accumulation of diacylglycerol at the PM produced during episodes of abiotic stress.Competing Interest StatementThe authors have declared no competing interest.