Publication Date:
2017-09-21
Description:
Bacteria adapt to adverse environmental conditions by altering gene expression patterns. Recently, a novel stress adaptation mechanism has been described that allowsEscherichia colito alter gene expression at the post-transcriptional level. The key player in this regulatory pathway is the endoribonuclease MazF, the toxin component of the toxin-antitoxin modulemazEFthat is triggered by various stressful conditions. In general, MazF degrades the majority of transcripts by cleaving at ACA sites, which results in the retardation of bacterial growth. Furthermore, MazF can process a small subset of mRNAs and render them leaderless by removing their ribosome binding site. MazF concomitantly modifies ribosomes, making them selective for the translation of leaderless mRNAs. In this study, we employed fluorescent reporter-systems to investigatemazEFexpression during stressful conditions, and to infer consequences of the mRNA processing mediated by MazF on gene expression at the single-cell level. Our results suggest thatmazEFtranscription is maintained at low levels in single cells encountering adverse conditions, such as antibiotic stress or amino acid starvation. Moreover, using thegrcAmRNA as a model for MazF-mediated mRNA processing, we found that MazF activation promotes heterogeneity in thegrcAreporter expression, resulting in a subpopulation of cells with increased levels of GrcA reporter protein.
Electronic ISSN:
2167-8359
Topics:
Biology
,
Medicine
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