Protein Folding and Aggregation in the Cell

Abstract

Cellular protein misfolding and aggregation cause neurodegenerative disorders like Huntington, Parkinson, Alzheimer and prion diseases. The diseases may be predominantly caused by “gain-of-function” proteotoxicity, with misfolded proteins prefibrillar and fibrillar aggregates being the toxic species. Protein structure, folding and aggregation kinetics are predominantly investigated in vitro in aqueous solution with powerful biophysical techniques and methods. We study solvent-induced effects on protein aggregation with the focus of understanding the effects of the crowded cellular environment. We use a combination of fluorescence microscopy and temperature jump relaxation (1) to spatio-temporally resolve these events in a single living cell. The same instrument is used to perform the comparative in vitro measurements in dilute buffer, crowded environments and distinct solvents. We present new insights to the in vivo aggregation pathway of intrinsically discorded proteins.(1) S. Ebbinghaus, A. Dhar, J.D. McDonald and M. Gruebele. Protein folding stability and dynamics imaged in a living cell. Nature Methods, 7:319-323, 2010.