Heat shock protein-mediated resistance to high hydrostatic pressure in Escherichia coli.
A random library of Escherichia coli MG1655 genomic fragments fused to a promoterless green fluorescent protein (GFP) gene was constructed and screened by differential fluorescence induction for promoters that are induced after exposure to a sublethal high hydrostatic pressure stress. This screening yielded three promoters of genes belonging to the heat shock regulon (dnaK, lon, clpPX), suggesting a role for heat shock proteins in protection against, and/or repair of, damage caused by high pressure. Several further observations provide additional support for this hypothesis: (i). the expression of rpoH, encoding the heat shock-specific sigma factor sigma(32), was also induced by high pressure; (ii). heat shock rendered E. coli significantly more resistant to subsequent high-pressure inactivation, and this heat shock-induced pressure resistance followed the same time course as the induction of heat shock genes; (iii). basal expression levels of GFP from heat shock promoters, and expression of several heat shock proteins as determined by two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis of proteins extracted from pulse-labeled cells, was increased in three previously isolated pressure-resistant mutants of E. coli compared to wild-type levels.
Aertsen
Abram
A
Laboratory of Food Microbiology, Katholieke Universiteit Leuven, Leuven, Belgium.
Vanoirbeek
Kristof
K
De Spiegeleer
Philipp
P
Sermon
Jan
J
Hauben
Kristel
K
Farewell
Anne
A
Nyström
Thomas
T
Michiels
Chris W
CW
D003470:Culture Media; D004926:Escherichia coli / Q000235:genetics / Q000254:growth & development*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D049452:Green Fluorescent Proteins; D006360:Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism*; D018869:Heat-Shock Response; D006874:Hydrostatic Pressure; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D011401:Promoter Regions, Genetic
D003470:Culture Media; D029968:Escherichia coli Proteins; D006360:Heat-Shock Proteins; D008164:Luminescent Proteins; D049452:Green Fluorescent Proteins