Structural basis of the cell stress response. (360G-Wellcome-082053_Z_07_Z)

The purpose of the proposed sabbatical project is to take advantage of recent developments in cryo electron tomography and vitrified cell sectioning, in order to examine the structure of yeast cells during and after heat stress. Itwill enable me to combine our previous mechanistic work on individual molecular chaperones with studies of aggregate formation and clearance in vivo. A network of heat shock proteins has been implicated in the prevention and reversal of protein aggregation, but the details of aggregate structure and interaction with chaperones are poorly understood. With the facilities andexpertise now available at EMBL, I will be able to observe the three-dimensional arrangement of large macromolecular assemblies and organelles in yeast cells during the stress response. I will follow the courseof aggregation and examine the involvement of the cytoskeleton, ER, Golgi and lysosomes in processing aggregates through the proteasomal and autophagy pathways. As an extension of my existing collaboration with Prof B Bukau at the ZMBH, Heidelberg, I will be able to compare the processing of aggregates in wild-type cells with that in chaperone deletion mutants, with over expression of aggregation-prone polypeptides, and/or in prion strains, depending on the outcome of initial work.