title: CspR, a cold shock RNA-binding protein involved in the long-term survival and the virulence of Enterococcus faecalis.
abstract: By coprecipitation, we identified RNA-binding proteins in the Gram-positive opportunistic pathogen Enterococcus faecalis known to be deficient of the RNA chaperone Hfq. In particular, we characterized one belonging to the cold shock protein (Csp) family (Ef2925) renamed CspR for cold shock protein RNA binding. Compared to the wild-type strain, the ΔcspR mutant was less virulent in an insect infection model (Galleria mellonella) and exhibited a decreased persistence in mouse kidneys and a low survival rate in peritoneal macrophages. As expected, we found that the ΔcspR mutant strain was more impaired in its growth than the parental strain under cold conditions and in its long-term survival under nutrient starvation. All these phenotypes were restored after complementation of the ΔcspR mutant. In addition, Western blot analysis showed that CspR was overexpressed under cold shock conditions and in the stationary phase. Since CspR may act as an RNA chaperone, putative targets were identified using a global proteomic approach completed with transcriptomic assays. This study revealed that 19 proteins were differentially expressed in the ΔcspR strain (9 upregulated, 10 downregulated) and that CspR mainly acted at the posttranscriptional level. These data highlight for the first time the role of the RNA-binding protein CspR as a regulator in E. faecalis and its requirement in stress response and virulence in this important human pathogen.
authors.affiliation: Unité de Recherche Risques Microbiens, Equipe Stress Virulence, Université de Caen, Caen, France.
authors.forename: Charlotte
authors.initials: C
authors.lastname: Michaux
authors.forename: Cecilia
authors.initials: C
authors.lastname: Martini
authors.forename: Koki
authors.initials: K
authors.lastname: Shioya
authors.forename: Sandra
authors.initials: S
authors.lastname: Ahmed Lecheheb
authors.forename: Aurélie
authors.initials: A
authors.lastname: Budin-Verneuil
authors.forename: Pascal
authors.initials: P
authors.lastname: Cosette
authors.forename: Maurizio
authors.initials: M
authors.lastname: Sanguinetti
authors.forename: Axel
authors.initials: A
authors.lastname: Hartke
authors.forename: Nicolas
authors.initials: N
authors.lastname: Verneuil
authors.forename: Jean-Christophe
authors.initials: JC
authors.lastname: Giard
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D057773:Cold Shock Proteins and Peptides / Q000235:genetics / Q000378:metabolism*; D013293:Enterococcus faecalis / Q000235:genetics / Q000472:pathogenicity* / Q000502:physiology*; D017353:Gene Deletion; D015964:Gene Expression Regulation, Bacterial; D016908:Gram-Positive Bacterial Infections / Q000382:microbiology; D035001:Host Factor 1 Protein / Q000378:metabolism; D007668:Kidney / Q000382:microbiology; D017737:Macrophages, Peritoneal / Q000382:microbiology; D051379:Mice; D050296:Microbial Viability; D009036:Moths / Q000382:microbiology; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D016415:Sequence Alignment; D013312:Stress, Physiological / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D057773:Cold Shock Proteins and Peptides; D035001:Host Factor 1 Protein; D016601:RNA-Binding Proteins