The long term goal of this project is to understand how the chaperonin TRiC (also called CCT) mediates protein folding. Chaperonins are essential components of the cellular folding machinery. These large protein complexes, consisting of two stacked seven- to nine-membered rings, bind unfolded substrates in their central cavity and use binding and hydrolysis of ATP to mediate polypeptide folding. The folding of substrate proteins occurs in the central cavity formed by each ring. There are substantial differences between group I chaperonins, found in prokaryotic cells, and the distantly related group II chaperonins in Archaea and Eukarya. Group I chaperonins require a ring-shaped cofactor, such GroES for GroEL, that upon binding acts as a lid for the cavity, creating a folding chamber that encloses polypeptide substrates. Group II chaperonins are hetero-oligomeric and lack a GroES-like cofactor, suggesting that their conformational cycle is significantly different from group I chaperonins. The present proposal aims to elucidate the mechanism of the eukaryotic chaperonin TRiC (TCP1-Ring Complex, also called CCT). Despite its essential role in polypeptide folding, little is known about the mechanism and substrate binding properties of TRiC. To understand how TRiC facilitates folding we propose the following specific aims: 1. Characterize of the nucleotide cycle of the chaperonin TRiC 2. Define the molecular basis of TRiC-substrate interactions 3. Investigate the mechanism of TRiC-assisted substrate folding.

Public Health Relevance

The eukaryotic chaperonin TRiC is a ring-shaped hetero-oligomeric complex that folds many essential cellular proteins in an ATP-dependent manner. This project aims to understand the mechanism of TRiC-mediated folding. Recent observations have highlighted the links between TRiC and several pathological states including cancer and neurodegeneration. Thus our project will help deciphering the role of this chaperonin in cellular folding and provide therapies to ameliorate human misfolding disorders.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
2R01GM074074-05
Application #
8012932
Study Section
Special Emphasis Panel (ZRG1-CB-B (02))
Program Officer
Wehrle, Janna P
Project Start
2005-04-01
Project End
2014-06-30
Budget Start
2010-09-01
Budget End
2011-06-30
Support Year
5
Fiscal Year
2010
Total Cost
$406,771
Indirect Cost
Name
Stanford University
Department
Biology
Type
Schools of Arts and Sciences
DUNS #
009214214
City
Stanford
State
CA
Country
United States
Zip Code
94305
Knowlton, Jonathan J; Fernández de Castro, Isabel; Ashbrook, Alison W et al. (2018) The TRiC chaperonin controls reovirus replication through outer-capsid folding. Nat Microbiol 3:481-493
Lopez, Tom; Dalton, Kevin; Tomlinson, Anthony et al. (2017) An information theoretic framework reveals a tunable allosteric network in group II chaperonins. Nat Struct Mol Biol 24:726-733
Sahl, Steffen J; Lau, Lana; Vonk, Willianne I M et al. (2016) Delayed emergence of subdiffraction-sized mutant huntingtin fibrils following inclusion body formation. Q Rev Biophys 49:e2
Lopez, Tom; Dalton, Kevin; Frydman, Judith (2015) The Mechanism and Function of Group II Chaperonins. J Mol Biol 427:2919-30
Walzthoeni, Thomas; Joachimiak, Lukasz A; Rosenberger, George et al. (2015) xTract: software for characterizing conformational changes of protein complexes by quantitative cross-linking mass spectrometry. Nat Methods 12:1185-90
Neef, Daniel W; Jaeger, Alex M; Gomez-Pastor, Rocio et al. (2014) A direct regulatory interaction between chaperonin TRiC and stress-responsive transcription factor HSF1. Cell Rep 9:955-66
Joachimiak, Lukasz A; Walzthoeni, Thomas; Liu, Corey W et al. (2014) The structural basis of substrate recognition by the eukaryotic chaperonin TRiC/CCT. Cell 159:1042-1055
Kasembeli, Moses; Lau, Wilson Chun Yu; Roh, Soung-Hun et al. (2014) Modulation of STAT3 folding and function by TRiC/CCT chaperonin. PLoS Biol 12:e1001844
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
Sontag, Emily M; Joachimiak, Lukasz A; Tan, Zhiqun et al. (2013) Exogenous delivery of chaperonin subunit fragment ApiCCT1 modulates mutant Huntingtin cellular phenotypes. Proc Natl Acad Sci U S A 110:3077-82

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