COLLABORATIVE RESEARCH: Investigation of cell-cycle regulated roles of CSLD proteins during plant cytokinesis

纤维素是地球上最丰富的生物聚合物之一，是植物细胞壁的重要结构成分，也是木材、棉花和纸张的主要成分。纤维素也是一种重要的可再生材料，具有多种工业用途，包括作为可持续生物燃料的原料。尽管纤维素在自然界和工业中处于中心地位，但我们对纤维素是如何构造的仍然知之甚少。该项目使用综合实验和计算建模方法来研究最近表征的细胞壁淀粉酶家族的功能，称为纤维素淀粉酶样D（CSLD）蛋白。CSLDs在植物细胞分裂过程中起着关键作用，对植物的生长发育至关重要。了解CSLD功能将提供关键的洞察纤维素和类似的生物分子是如何形成的。该项目将在涉及U-M和UGA-CCRC实验室的合作中进行，该实验室将为研究生提供独特的跨学科培训经验。此外，该项目旨在为本科生提供参与研究的机会，通过对下一代科学家的教育提供社会效益。该提案调查了拟南芥中植物细胞壁沉积过程中CSLD脱氢酶的功能。CSLD蛋白在植物胞质分裂过程中发挥着重要作用，其亚细胞定位和稳定性受细胞周期调控。在这个项目中概述的实验将解决以下问题：1）CSLDs是一个独特的一类纤维素酶？2)胞质分裂过程中CSLD的丢失是否损害细胞壁的完整性？ 3)什么调节CSLD 5的靶向和周转？ 问题1将使用植物细胞壁降解酶的生化重建和计算模拟的组合来解决。 问题2将使用定量细胞成像来监测细胞分裂期间的细胞壁动力学。问题3将使用基于蛋白质组学的方法来确定胞质分裂期间调节CSLD 5稳定性的翻译后修饰，以及在M/G1转换期间参与不稳定CSLD 5的细胞组分的正向遗传筛选，一个细胞-该奖项反映了NSF的法定使命，并被认为是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。

Cellulose is one of the most abundant biological polymers on the planet, is an important structural component of plant cell walls, and is the main component of wood, cotton, and paper. Cellulose is also an important renewable material with diverse industrial uses, including as feedstock for sustainable biofuels. Despite its centrality in nature and industry, we still know little about how cellulose is constructed. This project uses integrated experimental and computational modeling approaches to investigate the functions of a recently characterized family of cell wall synthases, called cellulose synthase-like D (CSLD) proteins. CSLDs play pivotal roles during plant cell division, and are essential for plant growth and development. Understanding CSLD function will provide critical insight into how cellulose and similar biomolecules are formed. This project will be carried out in a collaboration involving U-M and UGA-CCRC laboratories that will provide graduate students unique interdisciplinary training experience. Additionally, the project has been designed to offer research opportunities for undergraduate participation, providing societal benefits through the education of the next generation of scientists.This proposal investigates the functions of CSLD synthases during plant cell wall deposition in Arabidopsis. CSLD proteins were recently shown to play novel roles during plant cytokinesis, and both subcellular targeting and stability of CSLD5 are cell-cycle regulated. The experiments outlined in this project will address the following questions: 1) Are CSLDs a distinct class of cellulose synthases? 2) Does loss of CSLD impair cell wall integrity during cytokinesis? 3) What regulates targeting and turnover of CSLD5? Question 1 will be addressed using a combination of biochemical reconstitution and computational simulations of plant cell wall synthases. Question 2 will be addressed using quantitative cellular imaging to monitor cell wall dynamics during cell division. Question 3 will be addressed using a proteomics-based approach to identify post-translational modifications regulating CSLD5 stability during cytokinesis, and a forward-genetic screen for cellular components involved in destabilizing CSLD5 during M/G1 transitions, a cell-cycle step largely uncharacterized in any eukaryotic system.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.