Elucidating the function of Carbohydrate Oxidases acting on Fungal Cell Wall – OxiWall

The fungal cell wall (FCW) is probably one of the most essential and widely shared structure throughout the fungal kingdom. Whether they be involved in plant biomass decay, pathogenesis or symbiotic associations filamentous fungi secrete a wide array of enzymes, so called carbohydrate-active enzymes (CAZymes), to modify and/or degrade carbohydrates. While most of these CAZymes have been studied for their propensity to act on exogenous substrates (such as plant cell wall polysaccharides), very little is known on their role in the FCW modification and processing. The FCW is an intricate, multi-layer matrix of glycoproteins and polysaccharides, containing notably an inner wall of chitin. Our working hypothesis is that a significant number of secreted CAZymes are directed to the FCW. In the OxiWall project, we will aim at elucidating the biological function of the oxidative chitinolytic enzymes, and associated partners, putatively acting on the cell wall chitin of the model fungal phytopathogen Ustilago maydis. To this end, we will use a combination of multidisciplinary approaches, including in vitro enzymology and in vivo studies.
We believe that deciphering the potential role of FCW-targeting enzymes, and their orchestration, is of utmost importance for a deeper biochemical understanding of fungi biology. From a biotechnological standpoint, various applications could emerge from this project, such as new enzymatic processes to generate environmentally and ethically responsible FCW-derived biomaterials and biomolecules. Further, we anticipate that the OxiWall results will open new avenues on the development of FCW-active CAZymes-specific inhibitors for controlling fungal diseases threatening food security and human health.