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Zhang Y, Zhang J, Xiao J, Wang H, Yang R, Guo X, Zheng Y, Yin Y, Zhang X. comCDE (Competence) Operon Is Regulated by CcpA in Streptococcus pneumoniae D39. Microbiol Spectr 2023; 11:e0001223. [PMID: 37036382 PMCID: PMC10269683 DOI: 10.1128/spectrum.00012-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Accepted: 02/16/2023] [Indexed: 04/11/2023] Open
Abstract
Natural transformation plays an important role in the formation of drug-resistant bacteria. Exploring the regulatory mechanism of natural transformation can aid the discovery of new antibacterial targets and reduce the emergence of drug-resistant bacteria. Competence is a prerequisite of natural transformation in Streptococcus pneumoniae, in which comCDE operon is the core regulator of competence. To date, only ComE has been shown to directly regulate comCDE transcription. In this study, a transcriptional regulator, the catabolite control protein A (CcpA), was identified that directly regulated comCDE transcription. We confirmed that CcpA binds to the cis-acting catabolite response elements (cre) in the comCDE promoter region to regulate comCDE transcription and transformation. Moreover, CcpA can coregulate comCDE transcription with phosphorylated and dephosphorylated ComE. Regulation of comCDE transcription and transformation by CcpA was also affected by carbon source signals. Together, these insights demonstrate the versatility of CcpA and provide a theoretical basis for reducing the emergence of drug-resistant bacteria. IMPORTANCE Streptococcus pneumoniae is a major cause of bacterial infections in humans, such as pneumonia, bacteremia, meningitis, otitis media, and sinusitis. Like most streptococci, S. pneumoniae is naturally competent and employs this ability to augment its adaptive evolution. The current study illustrates CcpA, a carbon catabolite regulator, can participate in the competence process by regulating comCDE transcription, and this process is regulated by different carbon source signals. These hidden abilities are likely critical for adaptation and colonization in the environment.
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Affiliation(s)
- Yapeng Zhang
- Key Laboratory of Diagnostic Medicine Designated by the Ministry of Education, Department of Laboratory Medicine, Chongqing Medical University, Chongqing, China
| | | | - Jiangming Xiao
- Key Laboratory of Diagnostic Medicine Designated by the Ministry of Education, Department of Laboratory Medicine, Chongqing Medical University, Chongqing, China
| | - Hanyi Wang
- Key Laboratory of Diagnostic Medicine Designated by the Ministry of Education, Department of Laboratory Medicine, Chongqing Medical University, Chongqing, China
| | - Rui Yang
- Key Laboratory of Diagnostic Medicine Designated by the Ministry of Education, Department of Laboratory Medicine, Chongqing Medical University, Chongqing, China
| | - Xinlin Guo
- Department of Medicine Laboratory, Children’s Hospital of Chongqing Medical University, Chongqing, China
| | - Yuqiang Zheng
- Department of Medicine Laboratory, Children’s Hospital of Chongqing Medical University, Chongqing, China
| | - Yibing Yin
- Key Laboratory of Diagnostic Medicine Designated by the Ministry of Education, Department of Laboratory Medicine, Chongqing Medical University, Chongqing, China
| | - Xuemei Zhang
- Key Laboratory of Diagnostic Medicine Designated by the Ministry of Education, Department of Laboratory Medicine, Chongqing Medical University, Chongqing, China
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Brennan AA, Harrington A, Guo M, Renshaw CP, Tillett RL, Miura P, Tal-Gan Y. Investigating the Streptococcus sinensis competence regulon through a combination of transcriptome analysis and phenotypic evaluation. MICROBIOLOGY (READING, ENGLAND) 2022; 168. [PMID: 36282148 DOI: 10.1099/mic.0.001256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Streptococcus sinensis is a recently identified member of the Mitis group of streptococci. This species has been associated with infective endocarditis; however its mechanisms of pathogenesis and virulence are not fully understood. This study aimed to investigate the influence of the competence-stimulating peptide (CSP) and the competence regulon quorum-sensing circuitry (ComABCDE) on subsequent gene transcription and expression, as well as resultant phenotypes. In this study we confirmed the native CSP identity, ascertained when endogenous CSP was produced and completed a transcriptome-wide analysis of all genes following CSP exposure. RNA sequencing analysis revealed the upregulation of genes known to be associated with competence, biofilm formation and virulence. As such, a variety of phenotypic assays were utilized to assess the correlation between increased mRNA expression and potential phenotype response, ultimately gaining insight into the effects of CSP on both gene expression and developed phenotypes. The results indicated that the addition of exogenous CSP aided in competence development and successful transformation, yielding an average transformation efficiency comparable to that of other Mitis group streptococci. Additional studies are needed to further delineate the effects of CSP exposure on biofilm formation and virulence. Overall, this study provides novel information regarding S. sinensis and provides a substantial foundation on which this species and its role in disease pathogenesis can be further investigated.
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Affiliation(s)
- Alec A Brennan
- Department of Chemistry, University of Nevada, Reno, 1664 North Virginia Street, Reno, Nevada 89557, USA
| | - Anthony Harrington
- Department of Chemistry, University of Nevada, Reno, 1664 North Virginia Street, Reno, Nevada 89557, USA
| | - Mingzhe Guo
- Department of Chemistry, University of Nevada, Reno, 1664 North Virginia Street, Reno, Nevada 89557, USA
| | - Clay P Renshaw
- Department of Chemistry, University of Nevada, Reno, 1664 North Virginia Street, Reno, Nevada 89557, USA
| | - Richard L Tillett
- Nevada Center for Bioinformatics, University of Nevada, Reno, 1664 North Virginia Street, Reno, Nevada 89557, USA
| | - Pedro Miura
- Department of Biology, University of Nevada, Reno, 1664 North Virginia Street, Reno, Nevada 89557, USA
| | - Yftah Tal-Gan
- Department of Chemistry, University of Nevada, Reno, 1664 North Virginia Street, Reno, Nevada 89557, USA
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Chu LC, Arede P, Li W, Urdaneta EC, Ivanova I, McKellar SW, Wills JC, Fröhlich T, von Kriegsheim A, Beckmann BM, Granneman S. The RNA-bound proteome of MRSA reveals post-transcriptional roles for helix-turn-helix DNA-binding and Rossmann-fold proteins. Nat Commun 2022; 13:2883. [PMID: 35610211 PMCID: PMC9130240 DOI: 10.1038/s41467-022-30553-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Accepted: 05/06/2022] [Indexed: 01/21/2023] Open
Abstract
RNA-binding proteins play key roles in controlling gene expression in many organisms, but relatively few have been identified and characterised in detail in Gram-positive bacteria. Here, we globally analyse RNA-binding proteins in methicillin-resistant Staphylococcus aureus (MRSA) using two complementary biochemical approaches. We identify hundreds of putative RNA-binding proteins, many containing unconventional RNA-binding domains such as Rossmann-fold domains. Remarkably, more than half of the proteins containing helix-turn-helix (HTH) domains, which are frequently found in prokaryotic transcription factors, bind RNA in vivo. In particular, the CcpA transcription factor, a master regulator of carbon metabolism, uses its HTH domain to bind hundreds of RNAs near intrinsic transcription terminators in vivo. We propose that CcpA, besides acting as a transcription factor, post-transcriptionally regulates the stability of many RNAs.
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Affiliation(s)
- Liang-Cui Chu
- Centre for Synthetic and Systems Biology, University of Edinburgh, Edinburgh, EH9 3BF, UK
| | - Pedro Arede
- Centre for Synthetic and Systems Biology, University of Edinburgh, Edinburgh, EH9 3BF, UK
| | - Wei Li
- Centre for Synthetic and Systems Biology, University of Edinburgh, Edinburgh, EH9 3BF, UK
| | - Erika C Urdaneta
- IRI Life Sciences, Humboldt University Berlin, 10115, Berlin, Germany
| | - Ivayla Ivanova
- Centre for Synthetic and Systems Biology, University of Edinburgh, Edinburgh, EH9 3BF, UK
| | - Stuart W McKellar
- Centre for Synthetic and Systems Biology, University of Edinburgh, Edinburgh, EH9 3BF, UK
| | - Jimi C Wills
- Cancer Research UK Edinburgh Centre, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, EH4 2XR, UK
| | - Theresa Fröhlich
- Centre for Synthetic and Systems Biology, University of Edinburgh, Edinburgh, EH9 3BF, UK
| | - Alexander von Kriegsheim
- Cancer Research UK Edinburgh Centre, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, EH4 2XR, UK
| | | | - Sander Granneman
- Centre for Synthetic and Systems Biology, University of Edinburgh, Edinburgh, EH9 3BF, UK.
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RNase Z Oxidative Degradation Impedes tRNA Maturation and is Involved in Streptococcal Translation Regulation in Response to Oxidative Stress. Microbiol Spectr 2021; 9:e0116721. [PMID: 34704809 PMCID: PMC8549757 DOI: 10.1128/spectrum.01167-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
When encountering oxidative stress, organisms selectively upregulate antioxidant genes and simultaneously suppress the translation of most other proteins. Eukaryotes employ multiple strategies to adjust translation at both the initiation and elongation stages; however, how prokaryotes modulate translation under oxidative stress remains unclear. Here, we report that upon hydrogen peroxide (H2O2) challenge, Streptococcus oligofermentans reduced translation via RNase Z (So-RNaseZ) oxidative degradation, thus hindering tRNA maturation. S. oligofermentans encodes all CCA-less tRNAs that require So-RNaseZ for 3′ end maturation. A combination of nonreducing SDS-PAGE and liquid chromatography/tandem mass spectrometry (LC/MS-MS) assays demonstrated that H2O2 oxidation induced Cys38-Cys149 disulfide linkages in recombinant So-RNaseZ protein, and serine substitution of Cys38 or Cys149 abolished these disulfide linkages. Consistently, redox Western blotting also determined intramolecular disulfide-linked So-RNaseZ in H2O2-treated S. oligofermentans cells. The disulfide-linked So-RNaseZ and monomer were both subject to proteolysis, whereas C149S mutation alleviated oxidative degradation of So-RNaseZ, suggesting that H2O2-mediated disulfide linkages substantially contributed to So-RNaseZ degradation. Accordingly, Northern blotting determined that tRNA precursor accumulation and mature tRNA species decrease in H2O2-treated S. oligofermentans. Moreover, reduced overall protein synthesis, as indicated by puromycin incorporation, and retarded growth of S. oligofermentans occurred in an H2O2 concentration-dependent manner. Overexpression of So-RNaseZ not only elevated tRNA precursor processing and protein synthesis but also partly rescued H2O2-suppressed S. oligofermentans growth. Moreover, So-RNaseZ oxidative degradation-mediated translation repression elevated S. oligofermentans survival under high H2O2 stress. Therefore, this work found that So-RNaseZ oxidative degradation-impeded tRNA maturation contributes to streptococcal translation repression and provides the oxidative stress adaptability for S. oligofermentans. IMPORTANCE Translation regulation is a common strategy used by organisms to reduce oxidative damage. Catalase-negative streptococci produce as well as tolerate high levels of H2O2. This work reports a novel translation regulation mechanism employed by Streptococcus oligofermentans in response to H2O2 challenge, in which the key tRNA endonuclease So-RNaseZ is oxidized to form Cys38-Cys149 disulfide linkages and both the disulfide-linked So-RNaseZ and monomers are subject to proteolysis; thus, tRNA maturation, protein translation, and growth are all suppressed. Notably, So-RNaseZ oxidative degradation-mediated translation repression offers oxidative adaptability to S. oligofermentans and enhances its survival against high H2O2 challenge. So-RNaseZ orthologs and H2O2-sensitive cysteines (Cys38 and Cys149) are widely distributed in Streptococcus and Lactococcus species genomes, which also encode all CCA-less tRNAs and lack catalase. Therefore, RNase Z oxidative degradation-based translation regulation could be widely employed by these lactic acid bacteria, including pathogenic streptococci, to cope with H2O2.
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