Department of Biology, University of Rome Tor Vergata, Rome, Italy.
IUBMB Life. 2012 Aug;64(8):710-6. doi: 10.1002/iub.1058. Epub 2012 Jun 19.
Phosphatidic acid is a phospholipid second messenger implicated in various cellular processes in eukaryotes. In plants, production of phosphatidic acid is triggered in response to a number of biotic and abiotic stresses. Here, we show that phosphatidic acid binds to 14-3-3 proteins, a family of regulatory proteins which bind client proteins in a phosphorylation-dependent manner. Binding of phosphatidic acid involves the same 14-3-3 region engaged in protein target binding. Consequently, micromolar phosphatidic acid concentrations significantly hamper the interaction of 14-3-3 proteins with the plasma membrane H(+)-ATPase, a well characterized plant 14-3-3 target, thus inhibiting the phosphohydrolitic enzyme activity. Moreover, the proton pump is inhibited when endogenous PA production is triggered by phospholipase D and the G protein agonist mastoparan-7. Hence, our data propose a possible mechanism involving PA that regulates 14-3-3-mediated cellular processes in response to stress.
磷脂酸是一种在真核生物的各种细胞过程中起作用的磷脂第二信使。在植物中，磷脂酸的产生是对许多生物和非生物胁迫的响应而触发的。在这里，我们表明磷脂酸与 14-3-3 蛋白结合，后者是一类调节蛋白，以磷酸化依赖的方式与客户蛋白结合。磷脂酸的结合涉及与蛋白靶标结合相同的 14-3-3 区域。因此，毫摩尔浓度的磷脂酸会显著阻碍 14-3-3 蛋白与质膜 H(+)-ATP 酶的相互作用，质膜 H(+)-ATP 酶是一种经过充分表征的植物 14-3-3 靶标，从而抑制磷酸水解酶的活性。此外，当磷脂酶 D 和 G 蛋白激动剂 mastoparan-7 触发内源性 PA 产生时，质子泵也会受到抑制。因此，我们的数据提出了一种可能的机制，涉及 PA，以响应胁迫调节 14-3-3 介导的细胞过程。
