The long-term goal of our research is to understand the biochemistry and cell biology of protein folding in eukaryotic cells. The proposed research will focus on folding events as they occur at the ribosome during synthesis of a polypeptide and will examine the role of molecular chaperones in the folding process. The conceptual framework required to understand the folding of proteins as they emerge from the ribosome originates from our previous work, which indicates that folding in the eukaryotic cytosol is mediated by a chaperone network that is physically and functionally linked to translation. The objective of this proposal is to elucidate the mechanism by which chaperones mediate the folding of newly synthesized proteins in eukaryotic cells. To gain insight into this process we identified critical questions that will allow us to understand de novo folding, namely: (i) how and when do chaperones contact the emerging nascent chains?;(ii) what is the relevance of chaperone-binding for de novo folding?;(iii) what is the contribution of different chaperone systems to overall folding in the cell? (iv) how do chaperones interact with the translation machinery? Our general strategy to answer these questions is to combine in vitro and in vivo approaches to obtain mechanistic and functional insights into the role of chaperones in cellular folding. The first two specific aims will analyze the folding of model proteins in vivo and in cell-free translation lysates that faithfully represent the intact cytosol. Since our in vivo analysis indicates that different proteins exhibit distinct chaperone requirements, the third specific aim will examine the contribution of different chaperones to cellular folding and will identify the substrate spectrum of different molecular chaperones. Finally, our fourth specific aim will explore the interaction between chaperones and the translational machinery.

National Institute of Health (NIH)
National Institute of General Medical Sciences (NIGMS)
Research Project (R01)
Project #
Application #
Study Section
Special Emphasis Panel (ZRG1-CB-G (02))
Program Officer
Wehrle, Janna P
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
Stanford University
Schools of Arts and Sciences
United States
Zip Code
Sontag, Emily Mitchell; Samant, Rahul S; Frydman, Judith (2017) Mechanisms and Functions of Spatial Protein Quality Control. Annu Rev Biochem 86:97-122
Hanebuth, Marie A; Kityk, Roman; Fries, Sandra J et al. (2016) Multivalent contacts of the Hsp70 Ssb contribute to its architecture on ribosomes and nascent chain interaction. Nat Commun 7:13695
Chartron, Justin W; Hunt, Katherine C L; Frydman, Judith (2016) Cotranslational signal-independent SRP preloading during membrane targeting. Nature 536:224-8
Shen, Koning; Calamini, Barbara; Fauerbach, Jonathan A et al. (2016) Control of the structural landscape and neuronal proteotoxicity of mutant Huntingtin by domains flanking the polyQ tract. Elife 5:
Pechmann, Sebastian; Chartron, Justin W; Frydman, Judith (2014) Local slowdown of translation by nonoptimal codons promotes nascent-chain recognition by SRP in vivo. Nat Struct Mol Biol 21:1100-5
Pechmann, Sebastian; Frydman, Judith (2014) Interplay between chaperones and protein disorder promotes the evolution of protein networks. PLoS Comput Biol 10:e1003674
Sontag, Emily Mitchell; Vonk, Willianne I M; Frydman, Judith (2014) Sorting out the trash: the spatial nature of eukaryotic protein quality control. Curr Opin Cell Biol 26:139-146
Duttler, Stefanie; Pechmann, Sebastian; Frydman, Judith (2013) Principles of cotranslational ubiquitination and quality control at the ribosome. Mol Cell 50:379-93
Geller, Ron; Andino, Raul; Frydman, Judith (2013) Hsp90 inhibitors exhibit resistance-free antiviral activity against respiratory syncytial virus. PLoS One 8:e56762
Willmund, Felix; del Alamo, Marta; Pechmann, Sebastian et al. (2013) The cotranslational function of ribosome-associated Hsp70 in eukaryotic protein homeostasis. Cell 152:196-209

Showing the most recent 10 out of 37 publications