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.
