1. An unconventional RNA-based thermosensor within the 5' UTR of Staphylococcus aureus cidA
- Author
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Caleb A. Burke, Francesco Righetti, Saleh A. Mohamed, Franz Narberhaus, Ahmed Salem, Megan E. Fris, Hebaallaha Hussein, Raeven A. Bastock, Richard E. Wiemels, Erin R. Murphy, Ronan K. Carroll, Afaf S. Fahmy, and Nahla S. Hassan
- Subjects
Molecular biology ,Staphylococcus ,Gene Expression ,Artificial Gene Amplification and Extension ,medicine.disease_cause ,Pathology and Laboratory Medicine ,Biochemistry ,Polymerase Chain Reaction ,Protein Structure, Secondary ,Post-Transcriptional Gene Regulation ,Genes, Reporter ,Untranslated Regions ,Gene expression ,Medicine and Health Sciences ,Staphylococcus Aureus ,RNA Processing, Post-Transcriptional ,RNA structure ,Regulation of gene expression ,0303 health sciences ,Multidisciplinary ,Virulence ,Messenger RNA ,Temperature ,Staphylococcal Infections ,Bacterial Pathogens ,Nucleic acids ,RNA, Bacterial ,5' Utr ,Staphylococcus aureus ,Medical Microbiology ,Medicine ,Pathogens ,Research Article ,Virulence Factors ,Science ,Biology ,DNA construction ,Microbiology ,Bacterial genetics ,03 medical and health sciences ,Bacterial Proteins ,Gene Types ,medicine ,Escherichia coli ,Genetics ,Humans ,Gene Regulation ,Gene ,Microbial Pathogens ,030304 developmental biology ,Reporter gene ,Bacteria ,030306 microbiology ,Gene Expression Profiling ,Organisms ,RNA ,Biology and Life Sciences ,Gene Expression Regulation, Bacterial ,Research and analysis methods ,Macromolecular structure analysis ,Molecular biology techniques ,Biofilms ,Plasmid Construction ,Mutagenesis, Site-Directed ,5' Untranslated Regions ,Genome, Bacterial ,Reporter Genes - Abstract
Staphylococcus aureus is a Gram-positive bacterial pathogen of global concern and a leading cause of bacterial infections worldwide. Asymptomatic carriage of S. aureus on the skin and in the anterior nares is common and recognized as a predisposing factor to invasive infection. Transition of S. aureus from the carriage state to that of invasive infection is often accompanied by a temperature upshift from approximately 33°C to 37°C. Such a temperature shift is known in other pathogens to influence gene expression, often resulting in increased production of factors that promote survival or virulence within the host. One mechanism by which bacteria modulate gene expression in response to temperature is by the regulatory activity of RNA-based thermosensors, cis-acting riboregulators that control translation efficiency. This study was designed to identify and characterize RNA-based thermosensors in S. aureus. Initially predicted by in silico analyses of the S. aureus USA300 genome, reporter-based gene expression analyses and site-specific mutagenesis were performed to demonstrate the presence of a functional thermosensor within the 5' UTR of cidA, a gene implicated in biofilm formation and survival of the pathogen. The nucleic sequence composing the identified thermosensor are sufficient to confer temperature-dependent post-transcriptional regulation, and activity is predictably altered by the introduction of site-specific mutations designed to stabilize or destabilize the structure within the identified thermosensor. The identified regulator is functional in both the native bacterial host S. aureus and in the distally related species Escherichia coli, suggesting that its regulatory activity is independent of host-specific factors. Interestingly, unlike the majority of bacterial RNA-based thermosensors characterized to date, the cidA thermosensor facilitates increased target gene expression at lower temperatures. In addition to the characterization of the first RNA-based thermosensor in the significant pathogen S. aureus, it highlights the diversity of function within this important class of ribo-regulators.
- Published
- 2018