Proteomic approaches and live cell imaging reveal unique aspects of delivery of cellulose synthase complexes to the plasma membrane

了解植物细胞是如何制造纤维素的，不仅为利用遗传工具诱导植物制造改良的细胞壁以实现可持续能源的重大进步提供了科学基础，而且还为植物细胞如何决定细胞扩张和细胞最终形状的重要和基本科学问题提供了有价值的见解。该项目还将为本科生，特别是妇女和代表性不足的少数民族提供研究机会。个人研究项目将针对各种本科研究计划，以吸引有才华的妇女和代表性不足的学生，并加强他们的研究生院和学术生涯的准备。该项目还将包括在宾夕法尼亚州立大学参加一个面向当地高中女生及其教师的外联活动，其形式是一个实践研究讲习班。纤维素微纤维是由一种称为纤维素合成酶复合物（CSC）的大蛋白复合物在质膜上合成的。CSC吸收糖单体并组装线性聚合物，结晶纤维素微纤维，这是地球上最丰富的生物聚合物。由于纤维素合成发生在质膜上，因此了解纤维素合成酶被运输到细胞表面的机制变得非常重要。活细胞成像，功能遗传学和蛋白质组学方法的强大组合将用于研究植物细胞如何使用胞吐作用将CSC传递到细胞表面。具体而言，将解决以下三个目标：1）确定植物特异性蛋白PATROL 1和保守的外囊复合物在纤维素生物合成中的作用。 2)确定CSC如何与PATROL 1和外囊复合体相关。 3)通过其伴侣的功能表征来定义PATROL 1在CSC分泌中的作用。总之，这些实验将为真核细胞运输机制的演变提供前所未有的见解。该项目将成为在实验科学探究背景下培训本科生、高中生和教师，特别是妇女和代表性不足的少数民族的工具。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的知识价值和更广泛的影响审查标准进行评估来支持。

An understanding of how plant cells make cellulose will not only provide scientific foundations for using genetic tools to coax plants into making modified cell walls for significant advances in sustainable energy, but also provide valuable insights for important and basic scientific questions of how a plant cell determines cell expansion and the final shape of the cell. This project will also provide research opportunities to undergraduate students, especially women and underrepresented minorities. Individual research projects will be tailored to various undergraduate research programs to attract talented women and underrepresented students and to enhance their preparation for graduate school and academic careers. This project will also include participation in an outreach event to local high school girls and their teachers in the form of a hands-on research workshop at Pennsylvania State University. Cellulose microfibrils are synthesized at the plasma membrane by a large protein complex called cellulose synthase complex (CSC). The CSC uptakes sugar monomers and assembles a linear polymer, crystalline cellulose microfibrils, which are the most abundant biopolymer on earth. Because cellulose synthesis occurs at the plasma membrane, understanding the mechanisms by which cellulose synthase is trafficked to the cell surface becomes very important. A robust combination of live cell imaging, functional genetics, and proteomics approaches will be used to study how plant cells use exocytosis to deliver CSC to the cell surface. Specifically, the following three objectives will be addressed: 1) Determine the role of plant-specific protein PATROL1 and the conserved exocyst complex in cellulose biosynthesis. 2) Determine how CSCs are associated with PATROL1 and the exocyst complex. 3) Define the role of PATROL1 in CSC secretion through functional characterization of its partners. Together, these experiments will provide unprecedented insights into the evolution of trafficking machinery of eukaryotic cells. The project will be a vehicle for training undergraduate students, high school students and teachers, especially women and underrepresented minorities, in the context of experimental scientific enquiry.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.