Laboratoire Reproduction et Développement des Plantes, Université de Lyon, ENS de Lyon, UCB Lyon 1, CNRS, INRA, F-69342 Lyon, France.
UMR 5200 Membrane Biogenesis Laboratory, CNRS-University of Bordeaux, INRA Bordeaux Aquitaine, 33140 Villenave d'Ornon, France.
Science. 2019 Apr 5;364(6435):57-62. doi: 10.1126/science.aav9959.
Rho guanosine triphosphatases (GTPases) are master regulators of cell signaling, but how they are regulated depending on the cellular context is unclear. We found that the phospholipid phosphatidylserine acts as a developmentally controlled lipid rheostat that tunes Rho GTPase signaling in Live superresolution single-molecule imaging revealed that the protein Rho of Plants 6 (ROP6) is stabilized by phosphatidylserine into plasma membrane nanodomains, which are required for auxin signaling. Our experiments also revealed that the plasma membrane phosphatidylserine content varies during plant root development and that the level of phosphatidylserine modulates the quantity of ROP6 nanoclusters induced by auxin and hence downstream signaling, including regulation of endocytosis and gravitropism. Our work shows that variations in phosphatidylserine levels are a physiological process that may be leveraged to regulate small GTPase signaling during development.
Rho 鸟苷三磷酸酶（GTPases）是细胞信号转导的主要调节剂，但它们如何根据细胞环境进行调节尚不清楚。我们发现，磷脂酰丝氨酸作为一种发育调控的脂质变阻器，可调节植物 6 号 Rho 蛋白（ROP6）的 Rho GTPase 信号。活细胞超分辨率单分子成像揭示，磷脂酰丝氨酸将 ROP6 稳定在质膜纳米域中，这对于生长素信号转导是必需的。我们的实验还表明，在植物根发育过程中，质膜磷脂酰丝氨酸含量发生变化，而且磷脂酰丝氨酸的水平调节生长素诱导的 ROP6 纳米簇的数量，从而调节下游信号转导，包括内吞作用和向重力性的调节。我们的工作表明，磷脂酰丝氨酸水平的变化是一种生理过程，可能被用来调节发育过程中小 GTPase 信号转导。
