Effects of Growth Phase and Temperature onσBActivity within aListeria monocytogenesPopulation: Evidence for RsbV-Independent Activation ofσBat Refrigeration Temperatures
Autor: | Eoin Cosgrave, Conor P. O'Byrne, Marta Utratna, Rhodri Ceredig, Claas Baustian |
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Rok vydání: | 2014 |
Předmět: |
0303 health sciences
education.field_of_study General Immunology and Microbiology biology 030306 microbiology Population General Medicine Bacillus subtilis biology.organism_classification medicine.disease_cause General Biochemistry Genetics and Molecular Biology Green fluorescent protein Microbiology Cell biology 03 medical and health sciences Regulon Listeria monocytogenes Transcription (biology) Sigma factor medicine education Transcription factor 030304 developmental biology |
Zdroj: | BioMed Research International. 2014:1-11 |
ISSN: | 2314-6141 2314-6133 |
DOI: | 10.1155/2014/641647 |
Popis: | The alternative sigma factorσBofListeria monocytogenesis responsible for regulating the transcription of many of the genes necessary for adaptation to both food-related stresses and to conditions found within the gastrointestinal tract of the host. The present study sought to investigate the influence of growth phase and temperature on the activation ofσBwithin populations ofL.monocytogenesEGD-e wild-type, ΔsigB,and ΔrsbVthroughout growth at both 4°C and 37°C, using a reporter fusion that couples expression of EGFP to the stronglyσB-dependent promoter oflmo2230. A similarσBactivation pattern within the population was observed in wt-egfpat both temperatures, with the highest induction ofσBoccurring in the early exponential phase of growth when the fluorescent population rapidly increased, eventually reaching the maximum in early stationary phase. Interestingly, induction ofσBactivity was heterogeneous, with only a proportion of the cells in the wt-egfppopulation being fluorescent above the background autofluorescence level. Moreover, significant RsbV-independent activation ofσBwas observed during growth at 4°C. This result suggests that an alternative route toσBactivation exists in the absence of RsbV, a finding that is not explained by the current model forσBregulation. |
Databáze: | OpenAIRE |
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