An SOS response induced by high pressure in Escherichia coli.
Although pressure is an important environmental parameter in microbial niches such as the deep sea and is furthermore used in food preservation to inactivate microorganisms, the fundamental understanding of its effects on bacteria remains fragmentary. Our group recently initiated differential fluorescence induction screening to search for pressure-induced Escherichia coli promoters and has already reported induction of the heat shock regulon. Here the screening was continued, and we report for the first time that pressure induces a bona fide SOS response in E. coli, characterized by the RecA and LexA-dependent expression of uvrA, recA, and sulA. Moreover, it was shown that pressure is capable of triggering lambda prophage induction in E. coli lysogens. The remnant lambdoid e14 element, however, could not be induced by pressure, as opposed to UV irradiation, indicating subtle differences between the pressure-induced and the classical SOS response. Furthermore, the pressure-induced SOS response seems not to be initiated by DNA damage, since DeltarecA and lexA1 (Ind-) mutants, which are intrinsically hypersensitive to DNA damage, were not sensitized or were only very slightly sensitized for pressure-mediated killing and since pressure treatment was not found to be mutagenic. In light of these findings, the current knowledge of pressure-mediated effects on bacteria is discussed.
Aertsen
Abram
A
Laboratory of Food Microbiology, K.U.Leuven, Kasteelpark Arenberg 22, B-3001 Heverlee, Belgium.
Van Houdt
Rob
R
Vanoirbeek
Kristof
K
Michiels
Chris W
CW
D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism; D019677:Artificial Gene Fusion; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D010582:Bacteriophage lambda / Q000235:genetics / Q000254:growth & development; D015169:Colony Count, Microbial; D004249:DNA Damage; D004265:DNA Helicases / Q000235:genetics / Q000378:metabolism; D004269:DNA, Bacterial / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial / Q000502:physiology; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins; D006874:Hydrostatic Pressure; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D013014:SOS Response, Genetics / Q000502:physiology*; D012697:Serine Endopeptidases / Q000235:genetics / Q000378:metabolism; D010948:Viral Plaque Assay; D014775:Virus Activation / Q000235:genetics / Q000502:physiology; D000099160:LexA Repressor Protein
D000251:Adenosine Triphosphatases; D001426:Bacterial Proteins; D004265:DNA Helicases; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins; D012697:Serine Endopeptidases; D000099160:LexA Repressor Protein; C053139:sulA protein, E coli; C068631:UvrA protein, E coli