New Twists in CDPK Regulation: dual-specificity kinases and a role for calmodulin

植物钙依赖性蛋白激酶（CPKs或CDPKs）是一个大的植物蛋白激酶家族，它们作为钙传感器调节一系列涉及生长、气孔孔径、激素信号传导和免疫/胁迫信号传导的过程。因此，对调节这些蛋白激酶的机制的深入了解是至关重要的。本项目的目的是进一步阐明最近发现的CDPK的两个新特性，酪氨酸自磷酸化和钙调蛋白（CaM）结合，以更好地了解这些因子如何调节CDPK活性和植物功能。该项目的总体目标是了解特定CDPKs的翻译后修饰如何调节其功能，并确定这些修饰在调节植物生长，发育和对环境刺激的反应中所起的作用。该方法将包括产生和测量磷酸CDPK突变体的活性，确定其对cam结合的影响，并使用定向突变体补充CDPK无效突变体以确定其对植物表型的影响。该项目将围绕两个主要目标来描述CDPKs的发生和调节作用：1)CDPKs在Ser， Thr和Tyr残基上的自磷酸化，以及2)CaM与CDPKs结合。研究将涉及体外重组蛋白（和位点定向突变体），这将指导转基因方法来检查植物的功能。提出的研究结果可能从根本上改变CDPK调控的两种范式。除了提供传统的学生培训外，该项目还将包括暑期项目，为招募代表性不足的群体提供机会，并让学生参与实验室活动。此外，新的植物生物学/生物技术专业科学硕士课程将吸引那些在学术研究之外接受职位培训的学生进行非论文研究项目。最后，从该项目中获得的所有生物材料将提供给研究界。

Plant calcium-dependent protein kinases (CPKs or CDPKs) are a large family of plant protein kinases that act as calcium sensors to regulate a range of processes involved in regulation of growth, stomatal aperture, hormone signaling, and immune/stress signaling. Hence, a solid understanding of the mechanisms that regulate these protein kinases is of fundamental importance. The aim of this project is to further elucidate two recently discovered novel properties of CDPKs, tyrosine autophosphorylation and calmodulin (CaM)-binding, to better understand how these factors regulate CDPK activity and plant function. The overall goals of the project are to understand how posttranslational modifications of specific CDPKs modulates their function, and to define the role these modifications play in regulating plant growth, development and responses to environmental stimuli. The approach will involve generating and measuring the activities of phosphosite CDPK mutants, determining their effect on CaM-binding, and using the directed mutants to complement CDPK null mutants to determine their effect on plant phenotype. The project will center around two broad objectives to characterize the occurrence and regulatory role of: 1) autophosphorylation of CDPKs on Ser, Thr and Tyr residues, and 2) CaM binding to CDPKs. Studies will involve recombinant proteins (and site-directed mutants) in vitro that will guide transgenic approaches to examine function in planta. The results of the proposed studies may fundamentally alter two paradigms of CDPK regulation. In addition to providing traditional student training, the project will also include summer programs that provide opportunities for recruiting underrepresented groups and involve students in lab activities. In addition, the new Professional Science Master's Program in Plant Biology/Biotechnology will engage students who are training for positions outside of academic research with a non-thesis research project. Finally, all biological materials derived from the project will be made available to the research community.