Signaling pathways in the response to stress conditions that cause nascent protein misfolding and aggregation stress

Protein aggregation is the abnormal association of misfolded proteins which have the potential to form larger aggregate structures that tend to be insoluble. There has been relatively little work aimed at identifying the different molecular species involved in protein aggregation and their relationship to cellular toxicity. The aim of this project is to use a yeast model to understand the cellular responses to toxicity caused by protein misfolding and aggregation. This will include protein aggregation caused by protein misfolding in both nascent and mature proteins. A key focus will be to elucidate the role of the Ras/PKA pathway in the response to stress conditions that cause nascent protein misfolding and aggregation stress. The Ras/PKA pathway is a highly conserved glucose sensing and signaling pathway that plays a major role in the control of metabolism, stress responses and cell proliferation. There are three PKA isoforms in yeast (Tpk1-3) and molecular biology approaches including mutant construction will be used to examine PKA isoform-specific stress responses. Quantitative proteomic approaches will be used to examine PKA complex formation in response to different stress conditions. This will include examining how the regulatory subunit (Bcy1) moderates PKA activity during stress conditions. Microscopy approaches will be used to examine the dynamics of aggregate formation as well the intracellular localization of PKA isoforms. This is a fundamental bioscience project that will generate tools applicable to the optimal expression of recombinant proteins relevant to industrial biotechnology. It will also increase our understanding of how stress conditions promote protein aggregation and the cell defense pathways that mitigate the associated stress. The project will combine traditional yeast molecular biology and genetic techniques with high-end microscopy and quantitative proteomic approaches. The project uses a combination of lab and computational approaches facilitating a systematic approach to understand the biology of protein aggregation. The student will therefore be trained within a multidisciplinary supervisory team with complementary expertise and experience.