Identification of thermolabile Escherichia coli proteins: prevention and reversion of aggregation by DnaK and ClpB.

Détails

ID Serval
serval:BIB_778671E6B78C
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Identification of thermolabile Escherichia coli proteins: prevention and reversion of aggregation by DnaK and ClpB.
Périodique
EMBO Journal
Auteur(s)
Mogk A., Tomoyasu T., Goloubinoff P., Rüdiger S., Röder D., Langen H., Bukau B.
ISSN
0261-4189 (Print)
ISSN-L
0261-4189
Statut éditorial
Publié
Date de publication
1999
Volume
18
Numéro
24
Pages
6934-6949
Langue
anglais
Résumé
We systematically analyzed the capability of the major cytosolic chaperones of Escherichia coli to cope with protein misfolding and aggregation during heat stress in vivo and in cell extracts. Under physiological heat stress conditions, only the DnaK system efficiently prevented the aggregation of thermolabile proteins, a surprisingly high number of 150-200 species, corresponding to 15-25% of detected proteins. Identification of thermolabile DnaK substrates by mass spectrometry revealed that they comprise 80% of the large (>/=90 kDa) but only 18% of the small (</=30 kDa) cytosolic proteins and include essential proteins. The DnaK system in addition acts with ClpB to form a bi-chaperone system that quantitatively solubilizes aggregates of most of these proteins. Efficient solubilization also occurred in an in vivo order-of-addition experiment in which aggregates were formed prior to induction of synthesis of the bi-chaperone system. Our data indicate that large-sized proteins are most vulnerable to thermal unfolding and aggregation, and that the DnaK system has central, dual protective roles for these proteins by preventing their aggregation and, cooperatively with ClpB, mediating their disaggregation. Keywords: chaperones/heat-shock response/Hsp70/protein denaturation/thermotolerance
Mots-clé
Bacterial Proteins/chemistry, Bacterial Proteins/isolation & purification, Chaperonin 10/metabolism, Chaperonin 60/metabolism, Cytosol/metabolism, Electrophoresis, Gel, Two-Dimensional, Electrophoresis, Polyacrylamide Gel, Escherichia coli/metabolism, Escherichia coli Proteins, HSP70 Heat-Shock Proteins/metabolism, HSP90 Heat-Shock Proteins/metabolism, Heat-Shock Proteins/metabolism, Hot Temperature, Kinetics, Mass Spectrometry, Methionine/metabolism, Molecular Chaperones/metabolism, Molecular Weight, Protein Denaturation, Protein Renaturation, Recombinant Proteins/chemistry, Recombinant Proteins/metabolism, Solubility, Spheroplasts/metabolism, Thermodynamics
Pubmed
Web of science
Open Access
Oui
Création de la notice
24/01/2008 21:02
Dernière modification de la notice
20/08/2019 15:34
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