Takáč Tomáš, Pechan Tibor, Šamajová Olga, Šamaj Jozef
Faculty of Science, Centre of the Region Haná for Biotechnological and Agricultural Research, Palacký University, Olomouc, Czechia.
Institute for Genomics, Biocomputing and Biotechnology, Mississippi Agricultural and Forestry Experiment Station, Mississippi State University, Starkville, MS, United States.
Front Plant Sci. 2019 Feb 18;10:89. doi: 10.3389/fpls.2019.00089. eCollection 2019.
Phospholipase D alpha 1 (PLDα1) is a phospholipid hydrolyzing enzyme playing multiple regulatory roles in stress responses of plants. Its signaling activity is mediated by phosphatidic acid (PA) production, capacity to bind, and modulate G-protein complexes or by interaction with other proteins. This work presents a quantitative proteomic analysis of two T-DNA insertion α mutants of . Remarkably, α knockouts caused differential regulation of many proteins forming protein complexes, while PLDα1 might be required for their stability. Almost one third of differentially abundant proteins (DAPs) in α mutants are implicated in metabolism and RNA binding. Latter functional class comprises proteins involved in translation, RNA editing, processing, stability, and decay. Many of these proteins, including those regulating chloroplast protein import and protein folding, share common functions in chloroplast biogenesis and leaf variegation. Consistently, α mutants showed altered level of TIC40 (a major regulator of protein import into chloroplast), differential accumulation of photosynthetic protein complexes and changed chloroplast sizes as revealed by immunoblotting, blue-native electrophoresis, and microscopic analyses, respectively. Our proteomic analysis also revealed that genetic depletion of PLDα1 also affected proteins involved in cell wall architecture, redox homeostasis, and abscisic acid signaling. Taking together, PLDα1 appears as a protein integrating cytosolic and plastidic protein translations, plastid protein degradation, and protein import into chloroplast in order to regulate chloroplast biogenesis in Arabidopsis.
磷脂酶Dα1（PLDα1）是一种磷脂水解酶，在植物应激反应中发挥多种调节作用。其信号活性由磷脂酸（PA）的产生、结合和调节G蛋白复合物的能力或与其他蛋白质的相互作用介导。这项工作对两个T-DNA插入α突变体进行了定量蛋白质组学分析。值得注意的是，α基因敲除导致许多形成蛋白质复合物的蛋白质的差异调节，而PLDα1可能是它们稳定性所必需的。α突变体中近三分之一的差异丰富蛋白（DAPs）与代谢和RNA结合有关。后一功能类别包括参与翻译、RNA编辑、加工、稳定性和降解的蛋白质。其中许多蛋白质，包括那些调节叶绿体蛋白质导入和蛋白质折叠的蛋白质，在叶绿体生物发生和叶片斑驳中具有共同功能。一致地，α突变体分别通过免疫印迹、蓝色天然电泳和显微镜分析显示，TIC40（叶绿体蛋白质导入的主要调节因子）水平改变、光合蛋白质复合物的差异积累和叶绿体大小改变。我们的蛋白质组学分析还表明，PLDα1的基因缺失也影响了参与细胞壁结构、氧化还原稳态和脱落酸信号传导的蛋白质。综上所述，PLDα1似乎是一种整合胞质和质体蛋白质翻译、质体蛋白质降解以及蛋白质导入叶绿体以调节拟南芥叶绿体生物发生的蛋白质。
