Collaborative Arabidopsis 2010 Project : Genomics and Proteomics Approaches to the Function of Tyrosine Phosphatases in Arabidopsis

可逆蛋白磷酸化是真核生物系统中最常见的细胞调控机制。研究表明，丝氨酸/苏氨酸磷酸化在植物生理发育调控中起着关键作用。然而，尽管酪氨酸磷酸化在动物中具有压倒性的重要性，但在高等植物中却基本上被忽视了。近年来首次从高等植物中鉴定出蛋白酪氨酸磷酸酶（PTP）。此外，从拟南芥基因组中鉴定出了21个编码推测ptp的基因。对4种ptp的遗传分析表明，它们在植物发育、激素信号传导和逆境反应中起着关键作用。这些研究为植物酪氨酸磷酸化的认识开辟了新的领域，开辟了信号转导研究的新领域。本项目采用多方面的方法，将蛋白质组学和基因组学的最先进技术与生物化学、分子和细胞生物学以及遗传学的现有方法相结合，以解决拟南芥中酪氨酸磷酸酶的功能。所有PTPs的cdna将被分离，这些假定的PTPs的酶特性将被表征，它们的表达模式和亚细胞定位将被确定，遗传模型将被产生和表征。为了了解PTP功能的分子机制，将使用质谱法鉴定PTP的体内底物。拟南芥磷酸化蛋白质组数据库将通过PlantP网站（http://plantsp.sdsc.edu/）.The)向公众开放，目的是了解所有酪氨酸磷酸酶在植物生长和发育过程中的功能和相互作用，包括整个植物和分子水平。这些信息将有助于实现2010年计划的总体目标：了解所有拟南芥基因的功能。该项目还将通过为高中生物教师建立夏季讲习班，将教育活动纳入研究计划。

Reversible protein phosphorylation is the most common mechanism for cellular regulation in eukaryotic systems. Studies have demonstrated that serine/threonine phosphorylation plays a key role in the regulation of plant physiology and development. However, tyrosine phosphorylation, despite its overwhelming importance in animals, was largely neglected in higher plants. Recently the first protein tyrosine phosphatase (PTP) has been characterized from higher plants. Furthermore, a diverse group of 21 genes encoding putative PTPs have been identified from the Arabidopsis genome. Genetic analyses of 4 PTPs have demonstrated that they serve critical functions in plant development, hormone signaling, and stress responses. These studies have broken new ground in the understanding of tyrosine phosphorylation in plants and opened up a new area of signal transduction research. In this project, a multifaceted approach is taken that combines most advanced technology in proteomics and genomics with existing procedures in biochemistry, molecular and cellular biology, and genetics to address the function of tyrosine phosphatases in Arabidopsis. The cDNAs for all PTPs will isolated, enzymatic properties of these putative PTPs will be characterized, their expression pattern and subcellular localization will be determined, and genetic models will be produced and characterized. To understand the molecular mechanism underlying PTP function, the in vivo substrates of PTPs will be identified using mass spectrometry. A useful database on phosphoproteome of Arabidopsis will be built and will be publicly accessible through PlantP website (http://plantsp.sdsc.edu/).The goal of this project is to understand the function and interplay of all tyrosine phosphatases in plant growth and developmental processes at both whole plant and molecular levels. Such information will contribute to the overall goal of 2010 program: to understand the function of all Arabidopsis genes. This project will also integrate educational activities into the research program by establishing a summer workshop for high school biology teachers.