title: Low temperature-induced systems failure in Escherichia coli: insights from rescue by cold-adapted chaperones.
abstract: The growth of Escherichia coli cells is impaired at temperatures below 21 degrees C and stops at 7.5 degrees C; however, growth of a transgenic strain producing the cold-adapted chaperones Cpn60 and Cpn10 from the psychrophilic bacterium Oleispira antarctica is good at low temperatures. The E. coli cpn(+) transgene offers a novel opportunity for examining the essential protein for cell viability at low temperatures. By screening a large-scale protein map (proteome) of cells of K-12 and its Cpn(+) transgene incubated at 4 degrees C, we identified 22 housekeeping proteins involved in systems failure of E. coli when confronted with low temperature. Through co-immunoprecipitation of Cpn60, Northern blot, and in vitro refolding, we systematically identified that protein-chaperone interactions are key determinants of their protein functions at low temperatures. Furthermore, chromosomal gene deletion experiments suggest that the mechanism of cold-induced systems failure in E. coli is cold-induced inactivation of the GroELS chaperonins and the resulting failure to refold cold-inactivated Dps, ClpB, DnaK and RpsB proteins. These findings: (1) indicate the potential importance of chaperones in cold sensitivity, cold adaptation and cold tolerance in cellular systems, and (2) suggest the identity of a few key cold-sensitive chaperone-interacting proteins that get inactivated and ultimately cause systems failure in E. coli cells at low temperatures.
authors.affiliation: Division of Microbiology, GBF-German Research Centre for Biotechnology, Braunschweig, Germany.
authors.forename: Massimo
authors.initials: M
authors.lastname: Strocchi
authors.forename: Manuel
authors.initials: M
authors.lastname: Ferrer
authors.forename: Kenneth N
authors.initials: KN
authors.lastname: Timmis
authors.forename: Peter N
authors.initials: PN
authors.lastname: Golyshin
mesh_terms: D000222:Adaptation, Physiological; D000465:Algorithms; D015152:Blotting, Northern; D015153:Blotting, Western; D002876:Chromosomes, Bacterial; D003080:Cold Temperature; D015180:Electrophoresis, Gel, Two-Dimensional; D004926:Escherichia coli / Q000235:genetics / Q000502:physiology*; D029968:Escherichia coli Proteins / Q000737:chemistry; D018832:Molecular Chaperones / Q000502:physiology*; D020543:Proteome; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D029968:Escherichia coli Proteins; D018832:Molecular Chaperones; D020543:Proteome