title: Dam methylation regulates the expression of SPI-5-encoded sopB gene in Salmonella enterica serovar Typhimurium.
abstract: DNA adenine methylation is an essential factor in Salmonella virulence. Here, we investigate the involvement of DNA adenine methylase (Dam) in the expression and translocation of a SPI-5-encoded effector of S. Typhimurium. SopB expression and secretion were determined using SopB-FLAG-tagged wild type and dam strains of S. Typhimurium. Western blot and quantitative reverse transcriptase PCR analysis showed that the dam mutant expresses lower levels of SopB protein and sopB mRNA than the wild type strain under SPI-1 and SPI-2 inducing conditions in vitro. SopB secretion was also considerably impaired in the absence of dam. In agreement with in vitro experiments, SopB synthesis in dam mutants recovered from infected epithelial cells and from murine mesenteric lymph nodes was reduced by 40% respect to the wild type strain (p < 0.05). SopB translocation was neither detected in the cytosol of epithelial cells nor in the cytosol of cells isolated from mesenteric lymph nodes infected with the dam mutant. Taken together, our results demonstrate that, in S. Typhimurium, Dam methylation modulates the expression and translocation of SPI-5-encoded SopB effector.
authors.affiliation: Instituto de Investigaciones en Microbiología y Parasitología Médica, Universidad de Buenos Aires-Consejo Nacional de Investigaciones Científicas y Técnicas (IMPaM, UBA-CONICET), Facultad de Medicina, Paraguay 2155, p12, C1121ABG, Buenos Aires, Argentina. Electronic address: monicagiaco@yahoo.com.ar.
authors.forename: Mónica N
authors.initials: MN
authors.lastname: Giacomodonato
authors.affiliation: Instituto de Investigaciones en Microbiología y Parasitología Médica, Universidad de Buenos Aires-Consejo Nacional de Investigaciones Científicas y Técnicas (IMPaM, UBA-CONICET), Facultad de Medicina, Paraguay 2155, p12, C1121ABG, Buenos Aires, Argentina.
authors.forename: Mariángeles Noto
authors.initials: MN
authors.lastname: Llana
authors.affiliation: Instituto de Investigaciones en Microbiología y Parasitología Médica, Universidad de Buenos Aires-Consejo Nacional de Investigaciones Científicas y Técnicas (IMPaM, UBA-CONICET), Facultad de Medicina, Paraguay 2155, p12, C1121ABG, Buenos Aires, Argentina.
authors.forename: María del Rosario Aya
authors.initials: Mdel R
authors.lastname: Castañeda
authors.affiliation: Instituto de Investigaciones en Microbiología y Parasitología Médica, Universidad de Buenos Aires-Consejo Nacional de Investigaciones Científicas y Técnicas (IMPaM, UBA-CONICET), Facultad de Medicina, Paraguay 2155, p12, C1121ABG, Buenos Aires, Argentina.
authors.forename: Fernanda
authors.initials: F
authors.lastname: Buzzola
authors.affiliation: Instituto de Investigaciones en Microbiología y Parasitología Médica, Universidad de Buenos Aires-Consejo Nacional de Investigaciones Científicas y Técnicas (IMPaM, UBA-CONICET), Facultad de Medicina, Paraguay 2155, p12, C1121ABG, Buenos Aires, Argentina.
authors.forename: Mauro D
authors.initials: MD
authors.lastname: García
authors.affiliation: Centro de Virología Animal, Instituto de Ciencia y Tecnología Dr. Cesar Milstein CONICET, Saladillo 2468, C1440FFX, Buenos Aires, Argentina.
authors.forename: Marina Gallo
authors.initials: MG
authors.lastname: Calderón
authors.affiliation: Instituto de Investigaciones en Microbiología y Parasitología Médica, Universidad de Buenos Aires-Consejo Nacional de Investigaciones Científicas y Técnicas (IMPaM, UBA-CONICET), Facultad de Medicina, Paraguay 2155, p12, C1121ABG, Buenos Aires, Argentina.
authors.forename: Sebastián H
authors.initials: SH
authors.lastname: Sarnacki
authors.affiliation: Instituto de Investigaciones en Microbiología y Parasitología Médica, Universidad de Buenos Aires-Consejo Nacional de Investigaciones Científicas y Técnicas (IMPaM, UBA-CONICET), Facultad de Medicina, Paraguay 2155, p12, C1121ABG, Buenos Aires, Argentina.
authors.forename: María C
authors.initials: MC
authors.lastname: Cerquetti
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000096:biosynthesis / Q000378:metabolism*; D015153:Blotting, Western; D019175:DNA Methylation; D004195:Disease Models, Animal; D004847:Epithelial Cells / Q000382:microbiology; D017353:Gene Deletion; D015964:Gene Expression Regulation, Bacterial; D044404:Genomic Islands; D008198:Lymph Nodes / Q000382:microbiology; D008807:Mice, Inbred BALB C; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012481:Salmonella Infections, Animal; D012486:Salmonella typhimurium / Q000235:genetics*; D015265:Site-Specific DNA-Methyltransferase (Adenine-Specific) / Q000235:genetics / Q000378:metabolism*; D037521:Virulence Factors / Q000096:biosynthesis
chemical_list: D001426:Bacterial Proteins; D037521:Virulence Factors; C058693:Dam methyltransferase; D015265:Site-Specific DNA-Methyltransferase (Adenine-Specific); C489224:SopB protein, Salmonella
keywords: DNA adenine methylase; SPI-5; Salmonella enterica serovar Typhimurium; SopB