scholarly journals Signal Recognition Particle RNA Contributes to Oxidative Stress Response in Deinococcus radiodurans by Modulating Catalase Localization

2020 ◽  
Vol 11 ◽  
Author(s):  
Runhua Han ◽  
Jaden Fang ◽  
Jessie Jiang ◽  
Elena K. Gaidamakova ◽  
Rok Tkavc ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Stress Response ◽  
Deinococcus Radiodurans ◽  
Protein Localization ◽  
Signal Recognition Particle ◽  
Oxidative Stress Response ◽  
Major Protein ◽  
Signal Recognition ◽  
Bacterial Survival ◽  
Transport Pathway

The proper functioning of many proteins requires their transport to the correct cellular compartment or their secretion. Signal recognition particle (SRP) is a major protein transport pathway responsible for the co-translational movement of integral membrane proteins as well as periplasmic proteins. Deinococcus radiodurans is a ubiquitous bacterium that expresses a complex phenotype of extreme oxidative stress resistance, which depends on proteins involved in DNA repair, metabolism, gene regulation, and antioxidant defense. These proteins are located extracellularly or subcellularly, but the molecular mechanism of protein localization in D. radiodurans to manage oxidative stress response remains unexplored. In this study, we characterized the SRP complex in D. radiodurans R1 and showed that the knockdown (KD) of the SRP RNA (Qpr6) reduced bacterial survival under hydrogen peroxide and growth under chronic ionizing radiation. Through LC-mass spectrometry (MS/MS) analysis, we detected 162 proteins in the periplasm of wild-type D. radiodurans, of which the transport of 65 of these proteins to the periplasm was significantly reduced in the Qpr6 KD strain. Through Western blotting, we further demonstrated the localization of the catalases in D. radiodurans, DR_1998 (KatE1) and DR_A0259 (KatE2), in both the cytoplasm and periplasm, respectively, and showed that the accumulation of KatE1 and KatE2 in the periplasm was reduced in the SRP-defective strains. Collectively, this study establishes the importance of the SRP pathway in the survival and the transport of antioxidant proteins in D. radiodurans under oxidative stress.

scholarly journals Catalase Expression inAzospirillum brasilenseSp7 Is Regulated by a Network Consisting of OxyR and Two RpoH Paralogs and Including an RpoE1→RpoH5 Regulatory Cascade

2018 ◽  
Vol 84 (23) ◽  
Author(s):  
Ashutosh Kumar Rai ◽  
Sudhir Singh ◽  
Sushil Kumar Dwivedi ◽  
Amit Srivastava ◽  
Parul Pandey ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Stress Response ◽  
Sinorhizobium Meliloti ◽  
Deinococcus Radiodurans ◽  
Oxidative Stress Response ◽  
Sigma Factors ◽  
Transcriptional Analysis ◽  
Content Type ◽  
Regulatory Cascade ◽  
Transcription Regulators

ABSTRACTThe genome ofAzospirillum brasilenseencodes five RpoH sigma factors: two OxyR transcription regulators and three catalases. The aim of this study was to understand the role they play during oxidative stress and their regulatory interconnection. Out of the 5 paralogs of RpoH present inA. brasilense, inactivation of onlyrpoH1rendersA. brasilenseheat sensitive. While transcript levels ofrpoH1were elevated by heat stress, those ofrpoH3andrpoH5were upregulated by H2O2. Catalase activity was upregulated inA. brasilenseand itsrpoH::kmmutants in response to H2O2except in the case of therpoH5::kmmutant, suggesting a role for RpoH5 in regulating inducible catalase. Transcriptional analysis of thekatN,katAI, andkatAII genes revealed that the expression ofkatNandkatAII was severely compromised in therpoH3::kmandrpoH5::kmmutants, respectively. Regulation ofkatNandkatAII by RpoH3 and RpoH5, respectively, was further confirmed in anEscherichia colitwo-plasmid system. Regulation ofkatAII by OxyR2 was evident by a drastic reduction in growth, KatAII activity, andkatAII::lacZexpression in anoxyR2::kmmutant. This study reports the involvement of RpoH3 and RpoH5 sigma factors in regulating oxidative stress response in alphaproteobacteria. We also report the regulation of an inducible catalase by a cascade of alternative sigma factors and an OxyR. Out of the three catalases inA. brasilense, those corresponding tokatNandkatAII are regulated by RpoH3 and RpoH5, respectively. The expression ofkatAII is regulated by a cascade of RpoE1→RpoH5 and OxyR2.IMPORTANCEIn silicoanalysis of theA. brasilensegenome showed the presence of multiple paralogs of genes involved in oxidative stress response, which included 2 OxyR transcription regulators and 3 catalases. So far,Deinococcus radioduransandVibrio choleraeare known to harbor two paralogs of OxyR, andSinorhizobium melilotiharbors three catalases. We do not yet know how the expression of multiple catalases is regulated in any bacterium. Here we show the role of multiple RpoH sigma factors and OxyR in regulating the expression of multiple catalases inA. brasilenseSp7. Our work gives a glimpse of systems biology ofA. brasilenseused for responding to oxidative stress.

scholarly journals The Novel ncRNA OsiR Positively Regulates Expression of katE2 and is Required for Oxidative Stress Tolerance in Deinococcus radiodurans

2020 ◽  
Vol 21 (9) ◽  
pp. 3200 ◽  
Author(s):  
Lihua Gao ◽  
Xiaonan Chen ◽  
Ye Tian ◽  
Yongliang Yan ◽  
Yuhua Zhan ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Stress Response ◽  
Stress Tolerance ◽  
Catalase Activity ◽  
Target Genes ◽  
Deinococcus Radiodurans ◽  
Oxidative Stress Response ◽  
Sequencing Analysis ◽  
Translation Efficiency ◽  
Oxidative Stress Tolerance

Deinococcus radiodurans is a polyextremophilic bacterium well known for its extreme resistance to irradiation, oxidative stress, and other damaging conditions. Many small noncoding RNAs (ncRNAs) in D. radiodurans have been identified by deep sequencing analysis and computational predictions. However, the precise roles of ncRNAs and their target genes in the oxidative stress response have not been investigated. Here, we report the identification and characterization of a novel ncRNA named OsiR (for oxidative stress-induced ncRNA). Oxidative stress tolerance analysis showed that deleting osiR significantly decreased viability, total antioxidant capacity, and catalase activity in D. radiodurans under oxidative stress conditions. Comparative phenotypic and qRT-PCR analyses of an osiR mutant identify a role of OsiR in regulating the expression of the catalase gene katE2. Microscale thermophoresis and genetic complementation showed that a 21-nt sequence in the stem–loop structure of OsiR (204–244 nt) directly base pairs with its counterpart in the coding region of katE2 mRNA (843–866 nt) via a 19 nt region. In addition, deletion of katE2 caused a significant reduction of catalase activity and oxidative stress tolerance similar to that observed in an osiR mutant. Our results show that OsiR positively regulates oxidative stress tolerance in D. radiodurans by increasing the mRNA stability and translation efficiency of katE2. This work provides a new regulatory pathway mediated by ncRNA for the oxidative stress response that most likely contributes to the extreme tolerances of D. radiodurans.

scholarly journals sRNA OsiA Stabilizes Catalase mRNA during Oxidative Stress Response of Deincoccus radiodurans R1

2019 ◽  
Vol 7 (10) ◽  
pp. 422 ◽  
Author(s):  
Yun Chen ◽  
Dong Xue ◽  
Wenjie Sun ◽  
Jiahui Han ◽  
Jiang Li ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Stress Response ◽  
Translational Regulation ◽  
Deinococcus Radiodurans ◽  
Extreme Environments ◽  
Oxidative Stress Response ◽  
Small Noncoding Rnas ◽  
Total Antioxidant ◽  
Increased Sensitivity ◽  
The Stability

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.

scholarly journals Environmental Conditions Modulate the Transcriptomic Response of Both Caulobacter crescentus Morphotypes to Cu Stress

2021 ◽  
Vol 9 (6) ◽  
pp. 1116
Author(s):  
Laurens Maertens ◽  
Pauline Cherry ◽  
Françoise Tilquin ◽  
Rob Van Houdt ◽  
Jean-Yves Matroule
Keyword(s):  
Oxidative Stress ◽  
Stress Response ◽  
Stress Responses ◽  
Caulobacter Crescentus ◽  
Oxidative Stress Response ◽  
Transport Systems ◽  
Transcriptomic Response ◽  
Swarmer Cell ◽  
Cu Stress ◽  
Cellular Environment

Bacteria encounter elevated copper (Cu) concentrations in multiple environments, varying from mining wastes to antimicrobial applications of copper. As the role of the environment in the bacterial response to Cu ion exposure remains elusive, we used a tagRNA-seq approach to elucidate the disparate responses of two morphotypes of Caulobacter crescentus NA1000 to moderate Cu stress in a complex rich (PYE) medium and a defined poor (M2G) medium. The transcriptome was more responsive in M2G, where we observed an extensive oxidative stress response and reconfiguration of the proteome, as well as the induction of metal resistance clusters. In PYE, little evidence was found for an oxidative stress response, but several transport systems were differentially expressed, and an increased need for histidine was apparent. These results show that the Cu stress response is strongly dependent on the cellular environment. In addition, induction of the extracytoplasmic function sigma factor SigF and its regulon was shared by the Cu stress responses in both media, and its central role was confirmed by the phenotypic screening of a sigF::Tn5 mutant. In both media, stalked cells were more responsive to Cu stress than swarmer cells, and a stronger basal expression of several cell protection systems was noted, indicating that the swarmer cell is inherently more Cu resistant. Our approach also allowed for detecting several new transcription start sites, putatively indicating small regulatory RNAs, and additional levels of Cu-responsive regulation.

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