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Chen H, Gao Q, Liu B, Zhang Y, Fang J, Wang S, Chen Y, Chen C. Identification of the global regulatory roles of RraA via the integrative transcriptome and proteome in Vibrio alginolyticus. mSphere 2024:e0002024. [PMID: 38934599 DOI: 10.1128/msphere.00020-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Accepted: 05/13/2024] [Indexed: 06/28/2024] Open
Abstract
Bacterial ribonuclease E (RNase E) is vital for posttranscriptional regulation by degrading and processing RNA. The RraA protein inhibits RNase E activity through protein-protein interactions, exerting a global regulatory effect on gene expression. However, the specific role of RraA remains unclear. In this study, we investigated rraA expression in Vibrio alginolyticus ZJ-T and identified three promoters responsible for its expression, resulting in transcripts with varying 5'-UTR lengths. During the stationary phase, rraA was significantly posttranscriptionally inhibited. Deletion of rraA had no impact on bacterial growth in rich medium Luria-Bertani broth with salt (LBS) but resulted in decreased biofilm formation and increased resistance to polymyxin B. Transcriptome analysis revealed 350 differentially expressed genes (DEGs) between the wild type and the rraA mutant, while proteome analysis identified 267 differentially expressed proteins (DEPs). Integrative analysis identified 55 genes common to both DEGs and DEPs, suggesting that RraA primarily affects gene expression at the posttranscriptional level. KEGG (Kyoto Encyclopedia of Genes and Genomes) analysis demonstrated that RraA facilitates the conversion of fatty acids, propionic acid, and branched-chain amino acids to acetyl-CoA while enhancing amino acid and peptide uptake. Notably, RraA positively regulates the expression of virulence-associated genes, including those involved in biofilm formation and the type VI secretion system. This study expands the understanding of the regulatory network of RraA through transcriptome analysis, emphasizing the importance of proteomic analysis in investigating posttranscriptional regulation.IMPORTANCERraA is an inhibitor protein of ribonuclease E that interacts with and suppresses its endonucleolytic activity, thereby playing a widespread regulatory role in the degradation and maturation of diverse mRNAs and noncoding small RNAs. However, the physiological functions and associated regulon of RraA in Vibrio alginolyticus have not been fully elucidated. Here, we report that RraA impacts virulence-associated physiological processes, namely, antibiotic resistance and biofilm formation, in V. alginolyticus. By conducting an integrative analysis of both the transcriptome and proteome, we revealed the involvement of RraA in carbon metabolism, amino acid catabolism, and transport, as well as in the type VI secretion system. Collectively, these findings elucidate the regulatory influence of RraA on multiple pathways associated with metabolism and pathogenesis in V. alginolyticus.
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Affiliation(s)
- Huizhen Chen
- South China Sea Institute of Oceanology, CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology (LMB), South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
- College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Qian Gao
- South China Sea Institute of Oceanology, CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology (LMB), South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
- College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Bing Liu
- South China Sea Institute of Oceanology, CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology (LMB), South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
- College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Ying Zhang
- South China Sea Institute of Oceanology, CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology (LMB), South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
| | - Jianxiang Fang
- South China Sea Institute of Oceanology, CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology (LMB), South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
- College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Songbiao Wang
- College of Marine Sciences, South China Agricultural University, Guangzhou, China
| | - Youqi Chen
- Guangzhou College of Technology and Business, Guangzhou, China
| | - Chang Chen
- South China Sea Institute of Oceanology, CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology (LMB), South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
- Xisha Marine Environmental National Observation and Research Station, Sansha, China
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Widney KA, Yang DD, Rusch LM, Copley SD. CRISPR-Cas9-assisted genome editing in E. coli elevates the frequency of unintended mutations. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.19.584922. [PMID: 38562785 PMCID: PMC10983943 DOI: 10.1101/2024.03.19.584922] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
Cas-assisted lambda Red recombineering techniques have rapidly become a mainstay of bacterial genome editing. Such techniques have been used to construct both individual mutants and massive libraries to assess the effects of genomic changes. We have found that a commonly used Cas9-assisted editing method results in unintended mutations elsewhere in the genome in 26% of edited clones. The unintended mutations are frequently found over 200 kb from the intended edit site and even over 10 kb from potential off-target sites. We attribute the high frequency of unintended mutations to error-prone polymerases expressed in response to dsDNA breaks introduced at the edit site. Most unintended mutations occur in regulatory or coding regions and thus may have phenotypic effects. Our findings highlight the risks associated with genome editing techniques involving dsDNA breaks in E. coli and likely other bacteria and emphasize the importance of sequencing the genomes of edited cells to ensure the absence of unintended mutations.
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Affiliation(s)
- Karl A. Widney
- Department of Molecular, Cellular and Developmental Biology, University of Colorado Boulder, Boulder, CO, 80309, USA
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO, 80309, USA
- Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder, CO, 80205, USA
| | - Dong-Dong Yang
- Department of Molecular, Cellular and Developmental Biology, University of Colorado Boulder, Boulder, CO, 80309, USA
- Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder, CO, 80205, USA
| | - Leo M. Rusch
- Department of Molecular, Cellular and Developmental Biology, University of Colorado Boulder, Boulder, CO, 80309, USA
- Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder, CO, 80205, USA
| | - Shelley D. Copley
- Department of Molecular, Cellular and Developmental Biology, University of Colorado Boulder, Boulder, CO, 80309, USA
- Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder, CO, 80205, USA
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Lejars M, Hajnsdorf E. Bacterial RNase III: Targets and physiology. Biochimie 2024; 217:54-65. [PMID: 37482092 DOI: 10.1016/j.biochi.2023.07.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Revised: 06/28/2023] [Accepted: 07/13/2023] [Indexed: 07/25/2023]
Abstract
Bacteria can rapidly adapt to changes in their environment thanks to the innate flexibility of their genetic expression. The high turnover rate of RNAs, in particular messenger and regulatory RNAs, provides an important contribution to this dynamic adjustment. Recycling of RNAs is ensured by ribonucleases, among which RNase III is the focus of this review. RNase III enzymes are highly conserved from prokaryotes to eukaryotes and have the specific ability to cleave double-stranded RNAs. The role of RNase III in bacterial physiology has remained poorly explored for a long time. However, transcriptomic approaches recently uncovered a large impact of RNase III in gene expression in a wide range of bacteria, generating renewed interest in the physiological role of RNase III. In this review, we first describe the RNase III targets identified from global approaches in 8 bacterial species within 4 Phyla. We then present the conserved and unique functions of bacterial RNase III focusing on growth, resistance to stress, biofilm formation, motility and virulence. Altogether, this review highlights the underestimated impact of RNase III in bacterial adaptation.
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Affiliation(s)
- Maxence Lejars
- Transborder Medical Research Center, Faculty of Medicine, University of Tsukuba, Ibaraki, Japan.
| | - Eliane Hajnsdorf
- UMR8261, CNRS, Université Paris Cité, Institut de Biologie Physico-Chimique, 13 Rue Pierre et Marie Curie, 75005, Paris, France.
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Han S, Byun JW, Lee M. Comparative Transcriptomic Analysis of Flagellar-Associated Genes in Salmonella Typhimurium and Its rnc Mutant. J Microbiol 2024; 62:33-48. [PMID: 38182942 DOI: 10.1007/s12275-023-00099-5] [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: 09/27/2023] [Revised: 11/28/2023] [Accepted: 11/29/2023] [Indexed: 01/07/2024]
Abstract
Salmonella enterica serovar Typhimurium (S. Typhimurium) is a globally recognized foodborne pathogen that affects both animals and humans. Endoribonucleases mediate RNA processing and degradation in the adaptation of bacteria to environmental changes and have been linked to the pathogenicity of S. Typhimurium. Not much is known about the specific regulatory mechanisms of these enzymes in S. Typhimurium, particularly in the context of environmental adaptation. Thus, this study carried out a comparative transcriptomic analysis of wild-type S. Typhimurium SL1344 and its mutant (∆rnc), which lacks the rnc gene encoding RNase III, thereby elucidating the detailed regulatory characteristics that can be attributed to the rnc gene. Global gene expression analysis revealed that the ∆rnc strain exhibited 410 upregulated and 301 downregulated genes (fold-change > 1.5 and p < 0.05), as compared to the wild-type strain. Subsequent bioinformatics analysis indicated that these differentially expressed genes are involved in various physiological functions, in both the wild-type and ∆rnc strains. This study provides evidence for the critical role of RNase III as a general positive regulator of flagellar-associated genes and its involvement in the pathogenicity of S. Typhimurium.
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Affiliation(s)
- Seungmok Han
- Department of Microbiology, College of Medicine, Hallym University, Chuncheon, 24252, Republic of Korea
| | - Ji-Won Byun
- Department of Microbiology, College of Medicine, Hallym University, Chuncheon, 24252, Republic of Korea
| | - Minho Lee
- Department of Microbiology, College of Medicine, Hallym University, Chuncheon, 24252, Republic of Korea.
- Institute of Medical Science, College of Medicine, Hallym University, Chuncheon, 24252, Republic of Korea.
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Relaxed Cleavage Specificity of Hyperactive Variants of Escherichia coli RNase E on RNA I. J Microbiol 2023; 61:211-220. [PMID: 36814003 DOI: 10.1007/s12275-023-00013-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 12/26/2022] [Accepted: 12/27/2022] [Indexed: 02/24/2023]
Abstract
RNase E is an essential enzyme in Escherichia coli. The cleavage site of this single-stranded specific endoribonuclease is well-characterized in many RNA substrates. Here, we report that the upregulation of RNase E cleavage activity by a mutation that affects either RNA binding (Q36R) or enzyme multimerization (E429G) was accompanied by relaxed cleavage specificity. Both mutations led to enhanced RNase E cleavage in RNA I, an antisense RNA of ColE1-type plasmid replication, at a major site and other cryptic sites. Expression of a truncated RNA I with a major RNase E cleavage site deletion at the 5'-end (RNA I-5) resulted in an approximately twofold increase in the steady-state levels of RNA I-5 and the copy number of ColE1-type plasmid in E. coli cells expressing wild-type or variant RNase E compared to those expressing RNA I. These results indicate that RNA I-5 does not efficiently function as an antisense RNA despite having a triphosphate group at the 5'-end, which protects the RNA from ribonuclease attack. Our study suggests that increased cleavage rates of RNase E lead to relaxed cleavage specificity on RNA I and the inability of the cleavage product of RNA I as an antisense regulator in vivo does not stem from its instability by having 5'-monophosphorylated end.
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Lee J, Shin E, Yeom JH, Park J, Kim S, Lee M, Lee K. Regulator of RNase E activity modulates the pathogenicity of Salmonella Typhimurium. Microb Pathog 2022; 165:105460. [DOI: 10.1016/j.micpath.2022.105460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Revised: 02/22/2022] [Accepted: 02/24/2022] [Indexed: 11/28/2022]
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Current and emerging tools of computational biology to improve the detoxification of mycotoxins. Appl Environ Microbiol 2021; 88:e0210221. [PMID: 34878810 DOI: 10.1128/aem.02102-21] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Biological organisms carry a rich potential for removing toxins from our environment, but identifying suitable candidates and improving them remain challenging. We explore the use of computational tools to discover strains and enzymes that detoxify harmful compounds. In particular, we will focus on mycotoxins-fungi-produced toxins that contaminate food and feed-and biological enzymes that are capable of rendering them less harmful. We discuss the use of established and novel computational tools to complement existing empirical data in three directions: discovering the prospect of detoxification among underexplored organisms, finding important cellular processes that contribute to detoxification, and improving the performance of detoxifying enzymes. We hope to create a synergistic conversation between researchers in computational biology and those in the bioremediation field. We showcase open bioremediation questions where computational researchers can contribute and highlight relevant existing and emerging computational tools that could benefit bioremediation researchers.
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Regulator of ribonuclease activity modulates the pathogenicity of Vibrio vulnificus. J Microbiol 2021; 59:1133-1141. [PMID: 34751908 DOI: 10.1007/s12275-021-1518-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 10/19/2021] [Accepted: 10/20/2021] [Indexed: 12/19/2022]
Abstract
RraA, a protein regulator of RNase E activity, plays a unique role in modulating the mRNA abundance in Escherichia coli. The marine pathogenic bacterium Vibrio vulnificus also possesses homologs of RNase E (VvRNase E) and RraA (VvRraA1 and VvRraA2). However, their physiological roles have not yet been investigated. In this study, we demonstrated that VvRraA1 expression levels affect the pathogenicity of V. vulnificus. Compared to the wild-type strain, the VvrraA1-deleted strain (ΔVvrraA1) showed decreased motility, invasiveness, biofilm formation ability as well as virulence in mice; these phenotypic changes of ΔVvrraA1 were restored by the exogenous expression of VvrraA1. Transcriptomic analysis indicated that VvRraA1 expression levels affect the abundance of a large number of mRNA species. Among them, the half-lives of mRNA species encoding virulence factors (e.g., smcR and htpG) that have been previously shown to affect VvrraA1 expression-dependent phenotypes were positively correlated with VvrraA1 expression levels. These findings suggest that VvRraA1 modulates the pathogenicity of V. vulnificus by regulating the abundance of a subset of mRNA species.
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Lee J, Lee M, Lee K. Trans-acting regulators of ribonuclease activity. J Microbiol 2021; 59:341-359. [PMID: 33779951 DOI: 10.1007/s12275-021-0650-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 12/28/2020] [Accepted: 12/28/2020] [Indexed: 12/16/2022]
Abstract
RNA metabolism needs to be tightly regulated in response to changes in cellular physiology. Ribonucleases (RNases) play an essential role in almost all aspects of RNA metabolism, including processing, degradation, and recycling of RNA molecules. Thus, living systems have evolved to regulate RNase activity at multiple levels, including transcription, post-transcription, post-translation, and cellular localization. In addition, various trans-acting regulators of RNase activity have been discovered in recent years. This review focuses on the physiological roles and underlying mechanisms of trans-acting regulators of RNase activity.
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Affiliation(s)
- Jaejin Lee
- Department of Life Science, Chung-Ang University, Seoul, 06974, Republic of Korea
| | - Minho Lee
- Department of Life Science, Chung-Ang University, Seoul, 06974, Republic of Korea.
| | - Kangseok Lee
- Department of Life Science, Chung-Ang University, Seoul, 06974, Republic of Korea.
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Lee J, Lee M, Lee K. Trans-acting regulators of ribonuclease activity. J Microbiol 2021:10.1007/s12275-021-0650-3. [PMID: 33565052 DOI: 10.1007/s12275-021-0650-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 12/28/2020] [Accepted: 12/28/2020] [Indexed: 11/29/2022]
Abstract
RNA metabolism needs to be tightly regulated in response to changes in cellular physiology. Ribonucleases (RNases) play an essential role in almost all aspects of RNA metabolism, including processing, degradation, and recycling of RNA molecules. Thus, living systems have evolved to regulate RNase activity at multiple levels, including transcription, post-transcription, post-translation, and cellular localization. In addition, various trans-acting regulators of RNase activity have been discovered in recent years. This review focuses on the physiological roles and underlying mechanisms of trans-acting regulators of RNase activity.
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Affiliation(s)
- Jaejin Lee
- Department of Life Science, Chung-Ang University, Seoul, 06974, Republic of Korea
| | - Minho Lee
- Department of Life Science, Chung-Ang University, Seoul, 06974, Republic of Korea.
| | - Kangseok Lee
- Department of Life Science, Chung-Ang University, Seoul, 06974, Republic of Korea.
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