Differences in virulence and in expression of PrfA and PrfA-regulated virulence genes of Listeria monocytogenes strains belonging to serogroup 4
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چکیده
منابع مشابه
Listeria monocytogenes B Modulates PrfA-Mediated Virulence Factor Expression †
Listeria monocytogenes B and positive regulatory factor A (PrfA) are pleiotropic transcriptional regulators that coregulate a subset of virulence genes. A positive regulatory role for B in prfA transcription has been well established; therefore, observations of increased virulence gene expression and hemolytic activity in a sigB strain initially appeared paradoxical. To test the hypothesis that...
متن کاملSigma B contributes to PrfA-mediated virulence in Listeria monocytogenes.
Transcription of the Listeria monocytogenes positive regulatory factor A protein (PrfA) is initiated from either of two promoters immediately upstream of prfA (prfAp(1) and prfAp(2)) or from the upstream plcA promoter. We demonstrate that prfAp(2) is a functional sigma(B)-dependent promoter and that a sigB deletion mutation affects the virulence phenotype of L. monocytogenes. Thus, the alternat...
متن کاملAttenuating Listeria monocytogenes Virulence by Targeting the Regulatory Protein PrfA
The transcriptional activator PrfA, a member of the Crp/Fnr family, controls the expression of some key virulence factors necessary for infection by the human bacterial pathogen Listeria monocytogenes. Phenotypic screening identified ring-fused 2-pyridone molecules that at low micromolar concentrations attenuate L. monocytogenes cellular uptake by reducing the expression of virulence genes. The...
متن کاملContributions of Listeria monocytogenes sigmaB and PrfA to expression of virulence and stress response genes during extra- and intracellular growth.
Listeria monocytogenes sigmaB and PrfA are pleiotropic regulators of stress response and virulence gene expression. Quantitative RT-PCR (qRT-PCR) was used to measure transcript levels of sigmaB- and PrfA-dependent genes in exponential-phase L. monocytogenes wild-type and DeltasigB strains as well as in bacteria exposed to environmental stresses (0.3 M NaCl or growth to stationary phase) or pres...
متن کاملA trans-Acting Riboswitch Controls Expression of the Virulence Regulator PrfA in Listeria monocytogenes
Riboswitches are RNA elements acting in cis, controlling expression of their downstream genes through a metabolite-induced alteration of their secondary structure. Here, we demonstrate that two S-adenosylmethionine (SAM) riboswitches, SreA and SreB, can also function in trans and act as noncoding RNAs in Listeria monocytogenes. SreA and SreB control expression of the virulence regulator PrfA by...
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ژورنال
عنوان ژورنال: Infection and Immunity
سال: 1996
ISSN: 0019-9567,1098-5522
DOI: 10.1128/iai.64.10.4008-4019.1996