Filamentous fungi are capable of producing and secreting proteins in stunning (i.e., > 100 g/L) quantities. Yet for many recombinant proteins productivity is much lower, often due to inadequate protein secretion. The overarching goal in this project is to develop a deeper understanding of protein secretion in filamentous fungi, so that strategies can be developed to improve productivity during fungal fermentation. It is hypothesized that fungal protein secretion and hyphal morphology are intimately linked, such that identification of morphological mutants will also select for both hypo- and hyper-secretors. To test this hypothesis, temperature sensitive (Ts) morphological mutants with aberrant protein secretion will be developed. These mutants will then be characterized using modern tools (i.e., genome sequencing and proteomic analysis) to identify the genes and molecular mechanisms responsible for their phenotypes. This combination of a classical genetic screen with modern "-omics" technology will allow rapid identification of gene function.
Filamentous fungi are used extensively in the bioprocess industry to produce a vast array of compounds worth billions of dollars. In contrast, fungal pathogens are a significant problem, responsible for significant morbidity and mortality in humans as well as billions of dollars in crop losses annually. Insight gained from this work, will not only improve productivity in fungal bioprocesses but has the potential to identify novel targets for improved antifungal therapies. The Ts mutant library generated will be made available to the broader fungal research community and has the potential for transformational impact because of the important role fungal morphology and protein secretion play in nearly all filamentous fungi. This research will also have broad impact on human capital, as it has a significant educational component. Much of the mutant screening work will be accomplished by undergraduate students, providing many a first exposure to research. At the graduate level, students will be trained at the interface of molecular biology and engineering and thus will gain valuable interdisciplinary experience. They will also gain supervisory experience as they help coordinate the research of undergraduates participating in the project.
