title: Connecting environment and genome plasticity in the characterization of transformation-induced SOS regulation and carbon catabolite control of the Vibrio cholerae integron integrase.
abstract: The human pathogen Vibrio cholerae carries a chromosomal superintegron (SI). The SI contains an array of hundreds of gene cassettes organized in tandem which are stable under conditions when no particular stress is applied to bacteria (such as during laboratory growth). Rearrangements of these cassettes are catalyzed by the activity of the associated integron integrase. Understanding the regulation of integrase expression is pivotal to fully comprehending the role played by this genetic reservoir for bacterial adaptation and its connection with the development of antibiotic resistance. Our previous work established that the integrase is regulated by the bacterial SOS response and that it is induced during bacterial conjugation. Here, we show that transformation, another horizontal gene transfer (HGT) mechanism, also triggers integrase expression through SOS induction, underlining the importance of HGT in genome plasticity. Moreover, we report a new cyclic AMP (cAMP)-cAMP receptor protein (CRP)-dependent regulation mechanism of the integrase, highlighting the influence of the extracellular environment on chromosomal gene content. Altogether, our data suggest an interplay between different stress responses and regulatory pathways for the modulation of the recombinase expression, thus showing how the SI remodeling mechanism is merged into bacterial physiology.
authors.affiliation: Institut Pasteur, Unité Plasticité du Génome Bactérien, Département Génomes et Génétique, Paris, France.
authors.forename: Zeynep
authors.initials: Z
authors.lastname: Baharoglu
authors.forename: Evelyne
authors.initials: E
authors.lastname: Krin
authors.forename: Didier
authors.initials: D
authors.lastname: Mazel
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D002244:Carbon / Q000378:metabolism*; D002373:Cyclic AMP Receptor Protein / Q000235:genetics / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D015971:Gene Expression Regulation, Enzymologic; D016680:Genome, Bacterial; D019426:Integrases / Q000235:genetics* / Q000378:metabolism; D032023:Integrons; D008969:Molecular Sequence Data; D013014:SOS Response, Genetics; D014169:Transformation, Bacterial; D014734:Vibrio cholerae / Q000201:enzymology* / Q000235:genetics* / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D002373:Cyclic AMP Receptor Protein; D002244:Carbon; D019426:Integrases