Publication Date:
2009
Short description:
Impaired synthesis and secretion of SopA in Salmonella Typhimurium dam mutants / Giacomodonato, M.n., Sarnacki, S.h., Llana, M.n., Cattaneo, A., Uzzau, S., Rubino, S., Cerquetti, M.c.. - In: FEMS MICROBIOLOGY LETTERS. - ISSN 0378-1097. - 292:1(2009), pp. 71-77. [10.1111/j.1574-6968.2008.01473.x]
abstract:
DNA adenine methylation regulates virulence gene expression in certain bacteria,
including Salmonella Typhimurium. The aim of this study was to investigate the
involvement of DNA adenine methylase (Dam) methylation in the expression and
secretion of the SPI-1 effector protein SopA. For this purpose, SopA–FLAG-tagged
wild-type and dam strains of Salmonella Typhimurium were constructed. The
expression and secretion of SopA were determined in bacterial culture and in
intracellular bacteria recovered from infected HEp-2 epithelial cells. Bacterial
culture supernatants and pellets were used to investigate secreted proteins and
cell-associated proteins, respectively. Western blot and quantitative reverse transcriptase
PCR analysis showed that the dam mutant expresses lower levels of SopA
than the wild-type strain. Interestingly, the strain lacking Dam synthesizes SopA
under nonpermissive conditions (28 1C). In addition, SopA secretion was drastically
impaired in the dam mutant. In vivo experiments showed that the intracellular
Salmonella dam mutant synthesizes SopA although in lower amounts than
the wild-type strain. Taken together, our results suggest that Dam methylation
modulates the expression and secretion of SopA in Salmonella Typhimurium.
including Salmonella Typhimurium. The aim of this study was to investigate the
involvement of DNA adenine methylase (Dam) methylation in the expression and
secretion of the SPI-1 effector protein SopA. For this purpose, SopA–FLAG-tagged
wild-type and dam strains of Salmonella Typhimurium were constructed. The
expression and secretion of SopA were determined in bacterial culture and in
intracellular bacteria recovered from infected HEp-2 epithelial cells. Bacterial
culture supernatants and pellets were used to investigate secreted proteins and
cell-associated proteins, respectively. Western blot and quantitative reverse transcriptase
PCR analysis showed that the dam mutant expresses lower levels of SopA
than the wild-type strain. Interestingly, the strain lacking Dam synthesizes SopA
under nonpermissive conditions (28 1C). In addition, SopA secretion was drastically
impaired in the dam mutant. In vivo experiments showed that the intracellular
Salmonella dam mutant synthesizes SopA although in lower amounts than
the wild-type strain. Taken together, our results suggest that Dam methylation
modulates the expression and secretion of SopA in Salmonella Typhimurium.
Iris type:
1.1 Articolo in rivista
List of contributors:
Giacomodonato, Mn; Sarnacki, Sh; Llana, Mn; Cattaneo, Asg; Uzzau, Sergio; Rubino, Salvatore; Cerquetti, Mc
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