Editor: Rustam Aminov
Expression of tmRNA in mycobacteria is increased by antimicrobial agents that target the ribosome
Article first published online: 1 AUG 2011
© 2011 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved
FEMS Microbiology Letters
Volume 322, Issue 2, pages 172–179, September 2011
How to Cite
Andini, N. and Nash, K. A. (2011), Expression of tmRNA in mycobacteria is increased by antimicrobial agents that target the ribosome. FEMS Microbiology Letters, 322: 172–179. doi: 10.1111/j.1574-6968.2011.02350.x
- Issue published online: 11 AUG 2011
- Article first published online: 1 AUG 2011
- Accepted manuscript online: 30 JUN 2011 03:59PM EST
- Received 14 March 2011; revised 6 May 2011; accepted 22 June 2011, Final version published online 1 August 2011.
The specialized RNA, tmRNA, is a central component of prokaryote trans-translation; a process that salvages stalled translational complexes. Evidence from other bacteria suggested that exposure to ribosome inhibitors elevated tmRNA levels, although it was unclear whether such changes resulted from increased tmRNA synthesis. Consequently, this study was initiated to determine the effect of ribosome inhibitors on the expression of tmRNA in mycobacteria. Exposure of Mycobacterium smegmatis to ribosome-targeting antimicrobial agents was associated with increased levels of the tmRNA precursor, pre-tmRNA, and mature tmRNA. For example, exposure to 16 μg mL−1 erythromycin for 3 h increased pre-tmRNA and tmRNA by 18- and 6-fold, respectively. Equivalent results were found following exposure of Mycobacterium bovis BCG to streptomycin. Exposure to antimicrobial agents with nonribosome targets did not affect tmRNA levels. The increased tmRNA levels were associated with increased output from the ssrA promoter, which controls tmRNA transcription, without evidence of a change in tmRNA degradation. These results suggest that the upregulation of tmRNA expression was an important response of bacteria to exposure to ribosome-inhibiting antimicrobial agents.