Thermotolerance requires refolding of aggregated proteins by substrate translocation through the central pore of ClpB

Cell. 2004 Nov 24;119(5):653-65. 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.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Cell Survival / genetics
  • Endopeptidase Clp
  • Escherichia coli / genetics
  • Escherichia coli / metabolism*
  • Escherichia coli Proteins / genetics
  • Escherichia coli Proteins / isolation & purification
  • Escherichia coli Proteins / metabolism*
  • HSP70 Heat-Shock Proteins / genetics
  • HSP70 Heat-Shock Proteins / metabolism*
  • Heat-Shock Proteins / genetics
  • Heat-Shock Proteins / isolation & purification
  • Heat-Shock Proteins / metabolism*
  • Heat-Shock Response / genetics*
  • 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


  • Escherichia coli Proteins
  • HSP70 Heat-Shock Proteins
  • Heat-Shock Proteins
  • Molecular Chaperones
  • Molecular Motor Proteins
  • Multiprotein Complexes
  • Endopeptidase Clp
  • dnaK protein, E coli
  • ClpB protein, E coli