The RNA chaperone Hfq impacts growth, metabolism and production of virulence factors in Yersinia enterocolitica.
To adapt to changes in environmental conditions, bacteria regulate their gene expression at the transcriptional but also at the post-transcriptional level, e.g. by small RNAs (sRNAs) which modulate mRNA stability and translation. The conserved RNA chaperone Hfq mediates the interaction of many sRNAs with their target mRNAs, thereby playing a global role in fine-tuning protein production. In this study, we investigated the significance of Hfq for the enteropathogen Yersina enterocolitica serotype O:8. Hfq facilitated optimal growth in complex and minimal media. Our comparative protein analysis of parental and hfq-negative strains suggested that Hfq promotes lipid metabolism and transport, cell redox homeostasis, mRNA translation and ATP synthesis, and negatively affects carbon and nitrogen metabolism, transport of siderophore and peptides and tRNA synthesis. Accordingly, biochemical tests indicated that Hfq represses ornithine decarboxylase activity, indole production and utilization of glucose, mannitol, inositol and 1,2-propanediol. Moreover, Hfq repressed production of the siderophore yersiniabactin and its outer membrane receptor FyuA. In contrast, hfq mutants exhibited reduced urease production. Finally, strains lacking hfq were more susceptible to acidic pH and oxidative stress. Unlike previous reports in other Gram-negative bacteria, Hfq was dispensable for type III secretion encoded by the virulence plasmid. Using a chromosomally encoded FLAG-tagged Hfq, we observed increased production of Hfq-FLAG in late exponential and stationary phases. Overall, Hfq has a profound effect on metabolism, resistance to stress and modulates the production of two virulence factors in Y. enterocolitica, namely urease and yersiniabactin.
Max von Pettenkofer Institute for Hygiene and Medical Microbiology, Ludwig Maximilians University, Munich, Germany.
Tamara
T
Kakoschke
Max von Pettenkofer Institute for Hygiene and Medical Microbiology, Ludwig Maximilians University, Munich, Germany.
Sara
S
Kakoschke
Max von Pettenkofer Institute for Hygiene and Medical Microbiology, Ludwig Maximilians University, Munich, Germany.
Giuseppe
G
Magistro
Max von Pettenkofer Institute for Hygiene and Medical Microbiology, Ludwig Maximilians University, Munich, Germany.
Sören
S
Schubert
Protein Analysis Unit, Adolf-Butenandt Institute, Ludwig Maximilians University, Munich, Germany.
Marc
M
Borath
Max von Pettenkofer Institute for Hygiene and Medical Microbiology, Ludwig Maximilians University, Munich, Germany.
Jürgen
J
Heesemann
Max von Pettenkofer Institute for Hygiene and Medical Microbiology, Ludwig Maximilians University, Munich, Germany.
Ombeline
O
Rossier
D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000096:biosynthesis; D058947:Bacterial Secretion Systems; D001430:Bacteriocins / Q000494:pharmacology; D050260:Carbohydrate Metabolism; D052978:Disk Diffusion Antimicrobial Tests; D055786:Gene Knockout Techniques; D035001:Host Factor 1 Protein / Q000502:physiology*; D007211:Indoles / Q000378:metabolism; D050296:Microbial Viability; D009955:Ornithine Decarboxylase / Q000378:metabolism; D018384:Oxidative Stress; D010636:Phenols / Q000378:metabolism; D020543:Proteome / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000096:biosynthesis; D013844:Thiazoles / Q000378:metabolism; D014510:Urease / Q000096:biosynthesis; D037521:Virulence Factors / Q000096:biosynthesis*; D015008:Yersinia enterocolitica / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*
D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D058947:Bacterial Secretion Systems; D001430:Bacteriocins; C090748:FyuA protein, Yersinia; D035001:Host Factor 1 Protein; D007211:Indoles; D010636:Phenols; D020543:Proteome; D011956:Receptors, Cell Surface; D013844:Thiazoles; D037521:Virulence Factors; C104398:yersiniabactin; C011330:Pesticin; D014510:Urease; D009955:Ornithine Decarboxylase