Robustness Analysis of Bacteria Heat Shock Response System

Bin Hu

Graduate School of Media and Governance

and

Institute of Advanced Biosciences

Keio University

Abstract:


Bacteria heat shock response is one of the most highly reserved fundamental self-protection mechanisms in life. With the heat shock response mechanism, bacteria can survive the temperature increase within a certain range. Crucial to the function of heat shock in E.coli is the hsp70 chaperone system. In this work, E-CELL, a software package aiming at large-scale modeling was used to analyze the 70kDa heat shock protein (Hsp70) chaperone mediated protein folding. We analyzed the kinetic characteristics of this chaperone system during folding of an unfolded protein using computer simulations, especially the robustness of this chaperone system in assist protein folding. Our simulation results are consistent with laboratory experiments reported and support the kinetic partitioning hypothesis. Our model suggests that for the final release of folded substrates GrpE is the most efficient regulator of this system. This supports the claim that GrpE functions as a system inherent thermosensor and its temperature dependent inactivation slows down the release of refolding substrates at heat shock temperatures. Furthermore, model simulations show that, although the DnaK chaperone system is robust in assisting protein folding, this robustness is limited by the availability of ATP.


Contents:


Note:

This Mori grant report is part of the paper: Hsp70-Mediated Protein Refolding in the E-Cell (Bin Hu, Matthias P. Mayer and Masaru Tomita), which was accepted for presentation at the 9th World Multiconference on Systemics, Cybernetics and Informatics (WMSCI 2005) to be held in Orlando, USA, in July 10-13, 2005.

Made by Bin Hu @ February 22, 2005