Project Details
Projekt
Chaperone interactions with ribosome-bound nascent chains: Role in protein folding
Applicant
Professor Dr. Franz-Ulrich Hartl
Subject Area
Biochemistry
Term
from 2008 to 2014
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 50070218
How proteins fold into their functionally active states upon synthesis is a fundamental question in biology. Nascent polypeptides emerging from the ribosomal tunnel are in danger of misfolding and/or aggregating in the crowded cellular milieu before attaining their functional tertiary structure. To circumvent this problem, cells have evolved a complex machinery of molecular chaperones which prevent misfolding and assist in the co- or post-translational folding of nascent polypeptides. Here we propose to continue our investigations of the mechanisms of molecular chaperone action in the context of protein synthesis. Specifically, we will use a combination of biophysical and structural approaches, such as FRET and cryo-electron microscopy, to study the conformational dynamics of nascent chains and the effects of various chaperones on their maturation. These experiments will be performed with in vitro translation systems. They will be complemented by a systems approach in E. coli and S. cerevisiae to define how nascent chains utilize the available chaperone repertoire. This part of the proposal will employ quantitative proteomics of in vivo stalled nascent chain-chaperone complexes. Isotope labelling experiments by SILAC will be performed to assess the quantitative changes in the chaperone interactions of nascent chains varying in their length, hydrophobic content and fold topology. The results of these studies will provide insight into the structural specificity of nascent chain-interacting chaperones and highlight possible differences between prokaryotic and eukaryotic folding mechanisms.
DFG Programme
Research Units
