SlyA Is a Transcriptional Regulator Involved in the Virulence of Enterococcus faecalis

• Published in: Infection and Immunity Vol. 79; no. 7; pp. 2638 - 2645
• Main Authors: Michaux, Charlotte, Sanguinetti, Maurizio, Reffuveille, Fany, Auffray, Yanick, Posteraro, Brunella, Gilmore, Michael S, Hartke, Axel, Giard, Jean-Christophe
• Format: Journal Article
• Language: English
• Published: Washington, DC American Society for Microbiology 01.07.2011
• Subjects: Animals; Bacterial Proteins - genetics; Bacterial Proteins - physiology; Bacteriology; Base Sequence; Biochemistry, Molecular Biology; Biological and medical sciences; crystal structure; Enterococcus faecalis; Enterococcus faecalis - genetics; Enterococcus faecalis - metabolism; Enterococcus faecalis - pathogenicity; Fundamental and applied biological sciences. Psychology; Galleria mellonella; Gene Expression Profiling; Gene Expression Regulation, Bacterial; gene overexpression; insects; kidneys; Larva - microbiology; Life Sciences; liver; loci; macrophages; mice; Microarray Analysis; microarray technology; Microbiology; Miscellaneous; Molecular Pathogenesis; Moths - microbiology; mutants; Phylogeny; Polymerase Chain Reaction; proteins; regulon; Sequence Analysis, DNA; stress response; transcription (genetics); transcription factors; Transcription Factors - genetics; Transcription Factors - physiology; Transcription, Genetic; virulence; Enterococcus faecalis; Streptococcaceae; Lactic acid bacteria; Virulence; Bacteria; Micrococcales; Immunity; pathogenesis; expression; oxidative stress response; gene; typhimurium; gelatinase; family; intracellular macrophage survival; urinary tract infection; resistance
• ISSN: 0019-9567; 1098-5522
• DOI: 10.1128/IAI.01132-10

Phylogenetic analysis of the crystal structure of the Enterococcus faecalis SlyA (EF_3002) transcriptional factor places it between the SlyA and MarR regulator subfamilies. Proteins of these families are often involved in the regulation of genes important for bacterial virulence and stress response. To gather evidence for the role of this putative regulator in E. faecalis biology, we dissected the genetic organization of the slyA-EF_3001 locus and constructed a slyA deletion mutant as well as complemented strains. Interestingly, compared to the wild-type parent, the ΔslyA mutant is more virulent in an insect infection model (Galleria mellonella), exhibits increased persistence in mouse kidneys and liver, and survives better inside peritoneal macrophages. In order to identify a possible SlyA regulon, global microarray transcriptional analysis was performed. This study revealed that the slyA-EF_3001 locus appears to be autoregulated and that 117 genes were differentially regulated in the ΔslyA mutant. In the mutant strain, 111 were underexpressed and 6 overexpressed, indicating that SlyA functions mainly as an activator of transcription.