Thermotolerance Requires Refolding of Aggregated Proteins by Substrate Translocation through the Central Pore of ClpB

• Published in: Cell Vol. 119; no. 5; pp. 653 - 665
• Main Authors: Weibezahn, Jimena, Tessarz, Peter, Schlieker, Christian, Zahn, Regina, Maglica, Zeljka, Lee, Sukyeong, Zentgraf, Hanswalter, Weber-Ban, Eilika U., Dougan, David A., Tsai, Francis T.F., Mogk, Axel, Bukau, Bernd
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 24.11.2004
• Subjects: Cell Survival - genetics; Endopeptidase Clp; Escherichia coli - genetics; Escherichia coli - metabolism; Escherichia coli Proteins - genetics; Escherichia coli Proteins - isolation & purification; Escherichia coli Proteins - metabolism; Heat-Shock Proteins - genetics; Heat-Shock Proteins - isolation & purification; Heat-Shock Proteins - metabolism; Heat-Shock Response - genetics; HSP70 Heat-Shock Proteins - genetics; HSP70 Heat-Shock Proteins - metabolism; Molecular Chaperones - genetics; Molecular Chaperones - metabolism; Molecular Motor Proteins; Molecular Sequence Data; Multiprotein Complexes - genetics; Multiprotein Complexes - metabolism; Protein Engineering; Protein Folding; Protein Transport - physiology; Sequence Homology, Amino Acid; Sequence Homology, Nucleic Acid
• ISSN: 0092-8674; 1097-4172
• DOI: 10.1016/j.cell.2004.11.027

Cell survival under severe thermal stress requires the activity of the ClpB (Hsp104) AAA+ chaperone that solubilizes and reactivates aggregated proteins in concert with the DnaK (Hsp70) chaperone system. How protein disaggregation is achieved and whether survival is solely dependent on ClpB-mediated elimination of aggregates or also on reactivation of aggregated proteins has been unclear. We engineered a ClpB variant, BAP, which associates with the ClpP peptidase and thereby is converted into a degrading disaggregase. BAP translocates substrates through its central pore directly into ClpP for degradation. ClpB-dependent translocation is demonstrated to be an integral part of the disaggregation mechanism. Protein disaggregation by the BAP/ClpP complex remains dependent on DnaK, defining a role for DnaK at early stages of the disaggregation reaction. The activity switch of BAP to a degrading disaggregase does not support thermotolerance development, demonstrating that cell survival during severe thermal stress requires reactivation of aggregated proteins.