Ann Hochschild

The main focus of my research has been transcription regulation and, more recently, the biology of prions. Primarily we have carried out these studies in E. coli, with an emphasis on genetic approaches. Early on, my group’s investigation of the minimal requirements for transcription activation led to the development of a bacteria-based two-hybrid assay for detecting and genetically dissecting protein-protein interactions. We subsequently used this tool to gain insight into post-initiation regulatory mechanisms. More recent work addresses the question of whether bacteria harbor prions. Having demonstrated that bacteria have the requisite machinery to propagate a model yeast prion, we uncovered evidence for the existence of endogenous prion-forming proteins in bacteria, including the transcription termination factor Rho from Clostridium botulinum and single-stranded DNA-binding proteins from diverse bacteria. Studies performed using an E. coli-based model support the idea that prions can provide a source of non-genetic phenotypic heterogeneity in the bacterial domain of life. Currently we are investigating the physiologic impacts of bacterial prions, as well as the intrinsic and extrinsic determinants of prion formation and propagation. Another new project is focused on translational fidelity and non-programmed ribosomal frameshifting.