Thermotolerance Requires Refolding of Aggregated Proteins by Substrate Translocation through the Central Pore of ClpB Academic Article uri icon

abstract

  • 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.

authors

  • Weibezahn, Jimena
  • Tessarz, Peter
  • Schlieker, Christian
  • Zahn, Regina
  • Maglica, Zeljka
  • Lee, Sukyeong
  • Zentgraf, Hanswalter
  • Weber-Ban, Eilika U
  • Dougan, David A
  • Tsai, Francis TF
  • Mogk, Axel
  • Bukau, Bernd

publication date

  • November 2004

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