Isolation and Characterization of Arabidopsis thaliana GenesEncoding Protein Serine/Threonine Phosphatase Regulatory Subunits.

近十年来，丝氨酸/苏氨酸蛋白磷酸酶（PP）已成为真核细胞代谢和发育的重要调控因子。PP控制必要的细胞功能，如完成有丝分裂和调节各种途径中的酶活性，如糖原代谢（在动物细胞中）和蔗糖生物合成（在光合植物细胞中）。PP活性受不同调控亚单位（RS）的控制。这些亚基改变了酶的特异性和活性。本研究方案概述了植物PP中RS的检测策略。迄今为止，只有一项关于这一主题的研究被报道。本研究的目的是利用分子克隆方法检测植物PP RS的存在，采用三种不同的策略从动物系统中分离编码RS的cDNA序列，以检测和分离植物RS基因。其次，利用聚合酶链反应从拟南芥基因组DNA中扩增RS DNA序列。第三，相互作用克隆将用于检测与PP催化亚基相互作用的蛋白质。通过这些方法分离的PP RS的表征将为控制植物PP的因素提供重要的初步线索。这项工作也将对植物细胞中蛋白质磷酸化控制事件的新兴研究领域产生重大影响。Sabine Rundle博士在过去的两年里一直是美国国家科学基金会植物生物学博士后研究奖学金的获得者。她最近在西卡罗莱纳大学获得了她的第一个终身教职，在那里她将继续研究某些酶，丝氨酸/苏氨酸蛋白磷酸酶在调节高等植物细胞功能中的作用。该奖项将为她的研究项目提供启动资助。这项研究的最初目标是从模式植物拟南芥中检测和分离这种酶成分的基因。这一系列研究的结果最终将有助于我们了解植物细胞功能的基本调控事件。＊＊＊

9499477 Rundle In the last decade serine/threonine protein phosphatases (PP) have emerged as important regulators of eukaryotic cell metabolism and development. PP control essential cellular functions such as the completion of mitosis and the regulation of enzyme activity in pathways as diverse as glycogen metabolism (in animal cells) and sucrose biosynthesis (in photosynthetic plant cells). PP activity is controlled by different regulatory subunits (RS). These subunits alter both the specificity and activity of the enzyme. This research proposal outlines strategies for detecting RS of PP of plants. To date only one study on this subject has been reported. The goal of this research is to use a molecular cloning approach to detect the presence of plant PP RS. Three different strategies will be used to isolate cDNA sequences encoding RS from animal systems to detect and isolate RS genes of plants. Second, the polymerase chain reaction will be used to amplify RS DNA sequences from A. thaliana genomic DNA. Third, interaction cloning will be used to detect proteins that interact with the catalytic subunit of PP. Characterization of the PP RS isolated by these methods will provide important first hints concerning factors that control plant PP. This work will also have a significant impact on the emerging field of study concerning protein phosphorylation- controlled events in plant cells. %%% Dr. Sabine Rundle has been the holder of an NSF Post-doctoral Research Fellowship in Plant Biology for the past two years. She has recently accepted her first tenure-track faculty position at Western Carolina University where she will pursue research on the role of certain enzymes, serine/threonine protein phosphatases in regulating cellular functions in higher plants. This award will provide a starter grant for support of her research program. The initial goals of this research are to detect and isolate genes for the components of this type of enzyme from the model plant, Arabidopsis thaliana. The results of this line of research ultimately will contribute to our understanding of fundamental regulatory events in plant cellular function. ***