Abstract
Deinococcus radiodurans adapts to challenging environments by modulating gene expression in response to oxidative stress. Recently, bacterial small noncoding RNAs (sRNAs) have been presumed to participate in the transcriptional or translational regulation of stress-responsive genes. We found 24 sRNAs that may be involved in the oxidative stress response of D. radiodurans by deep RNA sequencing. Moreover, a typical stress-inducible sRNA, IGR_3053, named OsiA, was predicted to bind to the mRNA of katA, katE, and sodC by the bioinformatics method. An osiA knockout of D. radiodurans displayed increased sensitivity to H2O2 and the decreased catalase activity and total antioxidant activity, suggesting that OsiA probably serves as a regulator in the adaptation to oxidative environments. Further microscale thermophoresis results demonstrated that OsiA can directly bind to the mRNA of katA, sodC, and katE. The stability test result of katA mRNA showed that its half-life was 2 min in the osiA mutant compared with 5 min in the wildtype(wt) strain. Our results indicated that OsiA can enhance the stability of katA mRNA and the activity of KatA and consequently the oxidation resistance of D.radiodurans. We are the first one to explore the super-strong oxidative stress resistance of D.radiodurans at the level of post-transcriptional regulation, and found a new pathway that provides a new explanation for the long-term adaptability of D.radiodurans in extreme environments.
Highlights
Deinococcus bacteria are extremophiles known for their superior resistance to ionizing radiation and oxidative stresses [1,2,3,4,5]
A previous study determined the transcriptome of D. radiodurans under 20 mM H2O2 treated for 30 min [13]; interestingly, we found that a relatively obvious phenotype appeared after 80 mM H2O2 treated for 30 min, we determined the transcriptome of D. radiodurans under such conditions
To globally identify small noncoding RNAs differentially expressed in response to oxidative stress in D. radiodurans, we exposed at least three replicate cultures of D. radiodurans to 80 mM H2O2
Summary
Deinococcus bacteria are extremophiles known for their superior resistance to ionizing radiation and oxidative stresses [1,2,3,4,5]. Some stress response transcriptional factors like CarD(RNA polymerase-interacting regulator), DrRRA(DNA-binding response regulator A), IrrE(Ionizing radiation resistance protein), OxyR have been reported to play significant roles in the stress resistance of D. radiodurans. Aside from these factors, Deinococcus bacteria have developed a conserved regulon, DdrO and PprI ( named as IrrE), that is involved in transcriptional regulation during the oxidative response [14,15]. It is speculated that it may be involved in several metabolic pathways of the oxidative stress response of D. radiodurans, so the biological function was studied in detail
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
