Tetracycline-inducible gene regulation in mycobacteria
| Autor: | Helen N. Murphy, Marian C. J. Blokpoel, Ronan F. O’Toole, Douglas B. Young, Graham R. Stewart, Ellen S. C. Runn, Brian D. Robertson, Siouxsie Wiles |
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| Rok vydání: | 2005 |
| Předmět: |
Operator Regions
Genetic Tetracycline Mycobacterium smegmatis Drug Resistance Biology Microbiology Corynebacterium glutamicum Mycobacterium 03 medical and health sciences Mice Genes Reporter Gene expression Genetics medicine Gene silencing Animals RNA Antisense Luciferases 030304 developmental biology Regulation of gene expression 0303 health sciences Luminescent Agents Dose-Response Relationship Drug 030306 microbiology Macrophages Gene Expression Regulation Bacterial Mycobacterium tuberculosis biology.organism_classification Molecular biology Mycobacterium bovis Antisense RNA Repressor Proteins Tetracyclines Methods Online medicine.drug |
| Zdroj: | Nucleic Acids Research |
| ISSN: | 1362-4962 |
| Popis: | A system for the tetracycline-inducible regulation of gene expression in mycobacteria has been developed. We have sub-cloned the tetRO region from the Corynebacterium glutamicum TetZ locus into a mycobacterial shuttle plasmid, making expression of genes cloned downstream of tetRO responsive to tetracycline. Using the luxAB-encoded luciferase from Vibrio harveyi as a reporter (pMind-Lx), we observed a 40-fold increase in light output from Mycobacterium smegmatis cultures 2 h after adding 20 ng ml(-1) of tetracycline. Similarly, exposure to the drug resulted in up to 20-fold increase in relative light units from M.bovis BCG carrying the reporter construct, and a 10-fold increase for M.tuberculosis. Tetracycline induction was demonstrated in log and stationary phase cultures. To evaluate whether this system is amenable to use in vivo, J774 macrophages were infected with M.bovis BCG[pMind-Lx], treated with amikacin to kill extracellular bacteria, and then incubated with tetracycline. A 10-fold increase in light output was measured after 24 h, indicating that intracellular bacteria are accessible and responsive to exogenously added tetracycline. To test the use of the tetracycline-inducible system for conditional gene silencing, mycobacteria were transformed with a pMind construct with tetRO driving expression of antisense RNA for the ftsZ gene. Bacterial cells containing the antisense construct formed filaments after 24 h exposure to tetracycline. These results demonstrate the potential of this tetracycline-regulated system for the manipulation of mycobacterial gene expression inside and outside cells. |
| Databáze: | OpenAIRE |
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