title: Immediate response of the DnaK molecular chaperone system to heat shock.
abstract: 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.
authors.affiliation: Biochemisches Institut der Universität Zürich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland.
authors.forename: Rahel K
authors.initials: RK
authors.lastname: Siegenthaler
authors.forename: John P A
authors.initials: JP
authors.lastname: Grimshaw
authors.forename: Philipp
authors.initials: P
authors.lastname: Christen
mesh_terms: 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
chemical_list: 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