title: Exposure of E. coli to DNA-Methylating Agents Impairs Biofilm Formation and Invasion of Eukaryotic Cells via Down Regulation of the N-Acetylneuraminate Lyase NanA.
abstract: DNA methylation damage can be induced by endogenous and exogenous chemical agents, which has led every living organism to develop suitable response strategies. We investigated protein expression profiles of Escherichia coli upon exposure to the alkylating agent methyl-methane sulfonate (MMS) by differential proteomics. Quantitative proteomic data showed a massive downregulation of enzymes belonging to the glycolytic pathway and fatty acids degradation, strongly suggesting a decrease of energy production. A strong reduction in the expression of the N-acetylneuraminate lyases (NanA) involved in the sialic acid metabolism was also observed. Using a null NanA mutant and DANA, a substrate analog acting as competitive inhibitor, we demonstrated that down regulation of NanA affects biofilm formation and adhesion properties of E. coli MV1161. Exposure to alkylating agents also decreased biofilm formation and bacterial adhesion to Caco-2 eukaryotic cell line by the adherent invasive E. coli (AIEC) strain LF82. Our data showed that methylation stress impairs E. coli adhesion properties and suggest a possible role of NanA in biofilm formation and bacteria host interactions.
authors.affiliation: Department of Chemical Sciences, University of Naples "Federico II" Naples, Italy.
authors.forename: Pamela
authors.initials: P
authors.lastname: Di Pasquale
authors.affiliation: Department of Molecular Medicine and Medical Biotechnology, University of Naples "Federico II" Naples, Italy.
authors.forename: Marianna
authors.initials: M
authors.lastname: Caterino
authors.affiliation: Department of Chemical Sciences, University of Naples "Federico II" Naples, Italy.
authors.forename: Angela
authors.initials: A
authors.lastname: Di Somma
authors.affiliation: Department of Chemical Sciences, University of Naples "Federico II" Naples, Italy.
authors.forename: Marta
authors.initials: M
authors.lastname: Squillace
authors.affiliation: Department of Biosciences, University of Milan Milan, Italy.
authors.forename: Elio
authors.initials: E
authors.lastname: Rossi
authors.affiliation: Department of Biosciences, University of Milan Milan, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Landini
authors.affiliation: Department of Public Health and Infectious Diseases, Pasteur Institute Cenci, Bolognetti Foundation, Sapienza University of Rome Rome, Italy.
authors.forename: Valerio
authors.initials: V
authors.lastname: Iebba
authors.affiliation: Department of Public Health and Infectious Diseases, Sapienza University of Rome Rome, Italy.
authors.forename: Serena
authors.initials: S
authors.lastname: Schippa
authors.affiliation: Department of Public Health and Infectious Diseases, Sapienza University of Rome Rome, Italy.
authors.forename: Rosanna
authors.initials: R
authors.lastname: Papa
authors.affiliation: Department of Public Health and Infectious Diseases, Sapienza University of Rome Rome, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Selan
authors.affiliation: Department of Public Health and Infectious Diseases, Sapienza University of Rome Rome, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Artini
authors.affiliation: Department of Public Health and Infectious Diseases, Pasteur Institute Cenci, Bolognetti Foundation, Sapienza University of RomeRome, Italy; IRCCS, San Raffaele Pisana Telematic UniversityRome, Italy.
authors.forename: Anna Teresa
authors.initials: AT
authors.lastname: Palamara
authors.forename: Annateresa
authors.initials: A
authors.lastname: Palamara
authors.affiliation: Department of Chemical Sciences, University of Naples "Federico II" Naples, Italy.
authors.forename: Angela
authors.initials: A
authors.lastname: Duilio
keywords: DNA alkylation; NanA lyase; adaptive response; adherent invasive Escherichia coli (AIEC); biofilm formation; comparative proteomics; virulence