The long-term goal of this research is to add to current understanding of the basic mechanisms of growth in the filamentous fungi. Fungi are a large and important group of microorganisms with major impacts on human affairs, through their ability to cause disease in humans and crops and through their usefulness in the production of foods and pharmaceuticals. Our ability to control the activities of both the harmful and the beneficial fungi can be improved through a better understanding of the cellular mechanisms underlying their growth and development. This project will investigate the functions of two proteins, which only recently have been shown to play roles in regulating the growth of filamentous fungi: protein kinase C (PKC), whose activity is essential to the structural integrity of fungal cell walls, and SccA, which is unique to filamentous fungi, and whose function interacts with that of PKC. The specific goals of this research are to determine how PKC and SccA interact with other proteins whose functions in cell wall metabolism are already understood and to elucidate the mechanisms by which PKC and SccA target to sites of cell wall growth. This will be accomplished in part by analyzing how the subcellular distributions of the two proteins are affected when fluorescently labeled (GFP tagged) versions of PKC and SccA are expressed in strains that carry mutations in genes for selected proteins that also function in wall metabolism. Reciprocal experiments will determine how the targeting and function of some of these same wall metabolism proteins are affected by normal and abnormal expression of PKC and SccA. By combining this information with time-lapse observations of the changing distributions of all studied proteins during development of wild type cells, predictive models will be created to guide further research into the interactions between PKC & SccA and other developmentally significant proteins. A second major goal of the research is to analyze how the various structural domains of PKC and SccA contribute to their ability to target correctly to sites of action in the cell and to perform their metabolic functions. This component of the project will involve creating site-mutated or truncated versions of PKC and SccA, and comparing their functions and distribution patterns to those of their normally constructed counterparts.
Broader Impact Undergraduate college students will play essential and central roles in all aspects of this research, thus gaining experience in modern molecular biology and becoming more able to make an informed choice about pursuing research careers. In addition to improving the infrastructure of research and education at Rhodes College, the project expands upon a successful existing collaboration between the awardee laboratory and four Historically Black Colleges in the Memphis, Tennessee area. Students from Rust College and Tougaloo College in Mississippi and Lemoyne-Owen College and Lane College in Tennessee will partner with their peers from Rhodes College in team-based research. The project thus strengthens the connections between the participating colleges, while expanding the range of research opportunities available to students from groups traditionally under-represented in the sciences.
