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

纤维素是地球上含量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，包括用作可持续生物燃料的原料。尽管纤维素在自然界和工业中居于中心地位，但我们对它是如何构成的知之甚少。该项目使用集成的实验和计算建模方法来研究最近鉴定的细胞壁合成酶家族的功能，称为纤维素合成酶样D(CSLD)蛋白。CSLD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的功能将为了解纤维素和类似生物分子是如何形成的提供关键的见解。该项目将在密歇根大学和UGA-CCRC实验室的合作下进行，这些实验室将为研究生提供独特的跨学科培训经验。此外，该项目旨在为大学生提供参与研究的机会，通过对下一代科学家的教育来提供社会效益。本提案研究了CSLD合成酶在拟南芥植物细胞壁沉积过程中的功能。最近发现CSLD蛋白在植物胞质分裂过程中发挥着新的作用，CSLD5的亚细胞靶向性和稳定性都受细胞周期的调控。本项目中概述的实验将解决以下问题：1)CSLD是一类独特的纤维素合成酶吗？2)CSLD的丢失是否会损害细胞质分裂过程中细胞壁的完整性？3)是什么调节了CSLD5的靶向和周转？问题1将结合生物化学重组和植物细胞壁合成酶的计算模拟来解决。问题2将使用定量细胞成像来监测细胞分裂过程中的细胞壁动态。问题3将使用基于蛋白质组学的方法来确定在胞质分裂期间调节CSLD5稳定性的翻译后修饰，以及在M/G1转变期间参与破坏CSLD5稳定的细胞成分的正向遗传筛查，这一细胞周期步骤在任何真核系统中基本上没有特征。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

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.