Chaperone Discovery 1
Human diseases that involve defects in protein folding include Alzheimer’s disease, cystic fibrosis, and type 2 diabetes. Chaperones constitute the major cellular defense against protein-folding stress, thus they play important roles in the development and progress of these diseases. We have devised a genetic selection that enables chaperone discovery by giving bacteria the stark choice between death and stabilizing poorly folded proteins. The bacteria respond to this selection by enhancing the expression of several distinct proteins. The expression of these folding helper proteins enables the bacteria to substantially increase the level of the unstable proteins and therefore live. This project will involve the genetic and biochemical characterization of these helper proteins. Many when purified turn out to be effective in vitro as molecular chaperones, which help prevent the aggregation of proteins and aid in protein refolding. Optimizing protein folding in the cell will thus lead to the uncovering of several previously uncharacterized chaperones.
Chaperone Discovery 2
Surprisingly little information is available about how chaperones and substrates interact or what exactly it is that chaperones do to affect the folding of their substrate proteins. This project will continue our fruitful investigation of the function and mechanism of a newly discovered chaperone called Spy, in part because its biophysical properties have proven it to be uniquely suited for examining the basic principles of chaperone action. These studies will enable us to understand how Spy binds proteins and how it facilitates protein refolding in unprecedented detail. These studies will significantly enhance our understanding of protein chaperone function and protein-folding mechanisms.