Immediate response of the DnaK molecular chaperone system to heat shock.
The familiar heat shock response in cells comprises the enhanced expression of molecular chaperones. In recent experiments with the Hsp70 system of Escherichia coli, the co-chaperone GrpE has been found to undergo a reversible thermal transition in the physiological temperature range. Here, we tested whether this thermal transition is of functional significance in the complete DnaK/DnaJ/GrpE chaperone system. We found that a mere increase in temperature resulted in a higher fraction of fluorescence-labeled peptides being sequestered by DnaK. This direct adaptation of the DnaK/DnaJ/GrpE chaperone system to heat shock conditions may serve to bridge the time lag of enhanced chaperone expression.
Siegenthaler
Rahel K
RK
Biochemisches Institut der Universität Zürich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland.
Grimshaw
John P A
JP
Christen
Philipp
P
D015081:2-Naphthylamine / Q000031:analogs & derivatives* / Q000378:metabolism; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000737:chemistry / Q000378:metabolism*; D005456:Fluorescent Dyes / Q000378:metabolism; D050956:HSP40 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins / Q000737:chemistry / Q000378:metabolism*; D006360:Heat-Shock Proteins / Q000737:chemistry / Q000378:metabolism*; D006358:Hot Temperature; D046911:Macromolecular Substances; D018832:Molecular Chaperones / Q000737:chemistry / Q000378:metabolism*; D010455:Peptides / Q000378:metabolism
D001426:Bacterial Proteins; C494635:DnaJ protein, E coli; D029968:Escherichia coli Proteins; D005456:Fluorescent Dyes; C068113:GrpE protein, Bacteria; C489400:GrpE protein, E coli; D050956:HSP40 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins; D006360:Heat-Shock Proteins; D046911:Macromolecular Substances; D018832:Molecular Chaperones; D010455:Peptides; C038518:acrylodan; D015081:2-Naphthylamine; C063842:dnaK protein, E coli