title: Temporal control of Dickeya dadantii main virulence gene expression by growth phase-dependent alteration of regulatory nucleoprotein complexes.
abstract: In bacteria, important genes are often controlled at the transcriptional level by several factors, forming a complex and intertwined web of interactions. Yet, transcriptional regulators are often studied separately and little information is available concerning their interactions. In this work, we dissect the regulation of the major virulence gene pelD in D. dadantii by taking into account the effects of individual binding sites for regulatory proteins FIS and CRP, and the impact of a newly discovered divergent promoter div. Using a combination of biochemistry and genetics approaches we provide an unprecedented level of detail on the multifactorial regulation of bacterial transcription. We show that the growth phase dependent regulation of pelD is under the control of changing composition of higher-order nucleoprotein complexes between FIS, CRP, div and pelD during the growth cycle that allow sequential expression of div and pelD in the early and late exponential growth phases, respectively. This work highlights the importance of "orphan" promoters in gene regulation and that the individual binding sites for a regulator can serve several purposes and have different effects on transcription, adding a new level of complexity to bacterial transcriptional regulation.
authors: Université Claude Bernard Lyon 1, F-69622 Villeurbanne, France; INSA-Lyon, F-69621 Villeurbanne, France; CNRS UMR5240 Microbiologie, Adaptation et Pathogénie, Villeurbanne, France.
authors: Alexandre
authors: A
authors: Duprey
authors: Université Claude Bernard Lyon 1, F-69622 Villeurbanne, France; INSA-Lyon, F-69621 Villeurbanne, France; CNRS UMR5240 Microbiologie, Adaptation et Pathogénie, Villeurbanne, France.
authors: Georgi
authors: G
authors: Muskhelishvili
authors: Université Claude Bernard Lyon 1, F-69622 Villeurbanne, France; INSA-Lyon, F-69621 Villeurbanne, France; CNRS UMR5240 Microbiologie, Adaptation et Pathogénie, Villeurbanne, France.
authors: Sylvie
authors: S
authors: Reverchon
authors: Université Claude Bernard Lyon 1, F-69622 Villeurbanne, France; INSA-Lyon, F-69621 Villeurbanne, France; CNRS UMR5240 Microbiologie, Adaptation et Pathogénie, Villeurbanne, France. Electronic address: william.nasser@insa-lyon.fr.
authors: William
authors: W
authors: Nasser
mesh_terms: D020563:Gammaproteobacteria / Q000254:growth & development / Q000821:virology*; D009698:Nucleoproteins / Q000378:metabolism*; D014158:Transcription, Genetic; D014774:Virulence / Q000235:genetics*
chemical_list: D009698:Nucleoproteins
keywords: CRP; FIS; Nucleoid-associated protein; Transcriptional regulation; pel gene