Hfq Is a Global Regulator That Controls the Pathogenicity of Staphylococcus aureus

Abstract

The Hfq protein is reported to be an RNA chaperone, which is involved in the stress response and the virulence of several pathogens. In E. coli, Hfq can mediate the interaction between some sRNAs and their target mRNAs. But it is controversial whether Hfq plays an important role in S. aureus. In this study, we found that the deletion of hfq gene in S. aureus 8325-4 can increase the surface carotenoid pigments. The hfq mutant was more resistant to oxidative stress but the pathogenicity of the mutant was reduced. We reveal that the Hfq protein can be detected only in some S. aureus strains. Using microarray and qRT-PCR, we identified 116 genes in the hfq mutant which had differential expression from the wild type, most of which are related to the phenotype and virulence of S. aureus. Among the 116 genes, 49 mRNAs can specifically bind Hfq protein, which indicates that Hfq also acts as an RNA binding protein in S. aureus. Our data suggest that Hfq protein of S. aureus is a multifunctional regulator involved in stress and virulence.

The importance of regulatory RNAs in Staphylococcus aureus

“…Hfq is present in most of the staphylococcal genomes, but differentially expressed (Liu et al, 2010). Its role in vivo is still controversial, while an hfq deletion mutant has no significant phenotype (Bohn et al, 2007;Romilly et al, 2012a).…”

Current knowledge on regulatory RNAs and their machineries inStaphylococcus aureus

“…11 The reason why Hfq cannot be detected has not been yet investigated although it was suggested that mutations in the promoter region led to a significant decrease of hfq transcription. 11 Interestingly, a recent work 92 showed that Hfq is detected only in several clinical strains and in the 8325-4 strain but not in COL and RN6390, two laboratory-adapted strains. 11,63 In 8325-4, where Hfq is expressed, its deletion decreases pathogenicity in a murine peritonitis infection model.…”

The Lsm Proteins: Ring Architectures for RNA Capture

“…An RNase E-Hfq-sRNA complex is thought to function in translational repression and subsequent mRNA destabilization and degradation (Morita et al, 2005;Morita et al, 2006). Additional functions of Hfq include ATPase activity (Sukhodolets & Garges, 2003), cellular stress response and modulation of virulence in some bacterial strains (Tsui et al, 1994;Fantappie et al, 2009;Liu et al, 2010). Interestingly, the virulence of the multi-drug resistant human pathogen S. aureus was decreased in Hfq-deletion strains.…”

“…Interestingly, the virulence of the multi-drug resistant human pathogen S. aureus was decreased in Hfq-deletion strains. (Liu et al, 2010).…”