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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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2
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Choi Y, Joo M, Song W, Lee M, Hyeon H, Kim HL, Yeom JH, Lee K, Shin E. Transcript-specific selective translation by specialized ribosomes bearing genome-encoded heterogeneous rRNAs in V. vulnificus CMCP6. J Microbiol 2022; 60:1162-1167. [PMID: 36422844 DOI: 10.1007/s12275-022-2437-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 10/26/2022] [Accepted: 10/27/2022] [Indexed: 06/16/2023]
Abstract
Ribosomes composed of genome-encoded heterogeneous rRNAs are implicated in the rapid adaptation of bacterial cells to environmental changes. A previous study showed that ribosomes bearing the most heterogeneous rRNAs expressed from the rrnI operon (I-ribosomes) are implicated in the preferential translation of a subset of mRNAs, including hspA and tpiA, in Vibrio vulnificus CMCP6. In this study, we show that HspA nascent peptides were predominantly bound to I-ribosomes. Specifically, I-ribosomes were enriched more than two-fold in ribosomes that were pulled down by immunoprecipitation of HspA peptides compared with the proportion of I-ribosomes in crude ribosomes and ribosomes pulled down by immunoprecipitation of RNA polymerase subunit β peptides in the wild-type (WT) and rrnI-completed strains. Other methods that utilized the incorporation of an affinity tag in 23S rRNA or chimeric rRNA tethering 16S and 23S rRNAs, which generated specialized functional ribosomes in Escherichia coli, did not result in functional I-ribosomes in V. vulnificus CMCP6. This study provides direct evidence of the preferential translation of hspA mRNA by I-ribosomes.
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Affiliation(s)
- Younkyung Choi
- Department of Life Science, Chung-Ang University, Seoul, 06974, Republic of Korea
| | - Minju Joo
- Department of Life Science, Chung-Ang University, Seoul, 06974, Republic of Korea
| | - Wooseok Song
- Department of Life Science, Chung-Ang University, Seoul, 06974, Republic of Korea
| | - Minho Lee
- Department of Microbiology, College of Medicine, Hallym University, Chuncheon, 24252, Republic of Korea
| | - Hana Hyeon
- Department of Life Science, Chung-Ang University, Seoul, 06974, Republic of Korea
| | - Hyun-Lee Kim
- Department of Life Science, Chung-Ang University, Seoul, 06974, Republic of Korea
| | - Ji-Hyun Yeom
- 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.
| | - Eunkyoung Shin
- Department of Life Science, Chung-Ang University, Seoul, 06974, Republic of Korea.
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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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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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Lodato PB. The effect of two ribonucleases on the production of Shiga toxin and stx-bearing bacteriophages in Enterohaemorrhagic Escherichia coli. Sci Rep 2021; 11:18372. [PMID: 34526533 PMCID: PMC8443680 DOI: 10.1038/s41598-021-97736-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 08/27/2021] [Indexed: 11/20/2022] Open
Abstract
Enterohaemorrhagic Escherichia coli (EHEC) comprise a group of intestinal pathogens responsible for a range of illnesses, including kidney failure and neurological compromise. EHEC produce critical virulence factors, Shiga toxin (Stx) 1 or 2, and the synthesis of Stx2 is associated with worse disease manifestations. Infected patients only receive supportive treatment because some conventional antibiotics enable toxin production. Shiga toxin 2 genes (stx2) are carried in λ-like bacteriophages (stx2-phages) inserted into the EHEC genome as prophages. Factors that cause DNA damage induce the lytic cycle of stx2-phages, leading to Stx2 production. The phage Q protein is critical for transcription antitermination of stx2 and phage lytic genes. This study reports that deficiency of two endoribonucleases (RNases), E and G, significantly delayed cell lysis and impaired production of both Stx2 and stx2-phages, unlike deficiency of either enzyme alone. Moreover, scarcity of both enzymes reduced the concentrations of Q and stx2 transcripts and slowed cell growth.
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Affiliation(s)
- Patricia B Lodato
- Department of Microbiology and Immunology, Kirksville College of Osteopathic Medicine, A.T. Still University, Kirksville, MO, 63501, USA.
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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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Lee M, Ryu M, Joo M, Seo YJ, Lee J, Kim HM, Shin E, Yeom JH, Kim YH, Bae J, Lee K. Endoribonuclease-mediated control of hns mRNA stability constitutes a key regulatory pathway for Salmonella Typhimurium pathogenicity island 1 expression. PLoS Pathog 2021; 17:e1009263. [PMID: 33524062 PMCID: PMC7877770 DOI: 10.1371/journal.ppat.1009263] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 02/11/2021] [Accepted: 01/01/2021] [Indexed: 01/04/2023] Open
Abstract
Bacteria utilize endoribonuclease-mediated RNA processing and decay to rapidly adapt to environmental changes. Here, we report that the modulation of hns mRNA stability by the endoribonuclease RNase G plays a key role in Salmonella Typhimurium pathogenicity. We found that RNase G determines the half-life of hns mRNA by cleaving its 5′ untranslated region and that altering its cleavage sites by genome editing stabilizes hns mRNA, thus decreasing S. Typhimurium virulence in mice. Under anaerobic conditions, the FNR-mediated transcriptional repression of rnc encoding RNase III, which degrades rng mRNA, and simultaneous induction of rng transcription resulted in rapid hns mRNA degradation, leading to the derepression of genes involved in the Salmonella pathogenicity island 1 (SPI-1) type III secretion system (T3SS). Together, our findings show that RNase III and RNase G levels-mediated control of hns mRNA abundance acts as a regulatory pathway upstream of a complex feed-forward loop for SPI-1 expression. Recent studies have shown that pathogenic bacteria with ribonuclease mutations display attenuated virulence, impaired mobility, and reduced proliferation in host cells. However, the molecular mechanisms underlying ribonuclease-associated pathogenesis have not yet been characterised. Here, we provide strong experimental evidence that the coordinated modulation of endoribonuclease activity constitutes an additional regulatory layer upstream of a complex feed-forward loop controlling global regulatory systems in the Salmonella pathogenicity island 1 (SPI-1) type III secretion system (T3SS). In addition, we showed that this regulatory pathway plays a key role in the virulence of S. Typhimurium in the host. Thus, our study improves the understanding of the mechanisms through which bacterial pathogens sense the host environment and respond precisely by expressing gene products required for adaptation to that particular niche.
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Affiliation(s)
- Minho Lee
- Department of Life Science, Chung-Ang University, Dongjak-Gu, Seoul, Republic of Korea
| | - Minkyung Ryu
- Department of Life Science, Chung-Ang University, Dongjak-Gu, Seoul, Republic of Korea
| | - Minju Joo
- Department of Life Science, Chung-Ang University, Dongjak-Gu, Seoul, Republic of Korea
| | - Young-Jin Seo
- Department of Life Science, Chung-Ang University, Dongjak-Gu, Seoul, Republic of Korea
| | - Jaejin Lee
- Department of Life Science, Chung-Ang University, Dongjak-Gu, Seoul, Republic of Korea
| | - Hong-Man Kim
- Department of Life Science, Chung-Ang University, Dongjak-Gu, Seoul, Republic of Korea
| | - Eunkyoung Shin
- Department of Pharmacy, Chung-Ang University, Dongjak-Gu, Seoul, Republic of Korea
| | - Ji-Hyun Yeom
- Department of Life Science, Chung-Ang University, Dongjak-Gu, Seoul, Republic of Korea
| | - Yong-Hak Kim
- Department of Microbiology, Daegu Catholic University School of Medicine, Daegu, Republic of Korea
- * E-mail: (Y-HK); (JB); (KL)
| | - Jeehyeon Bae
- Department of Pharmacy, Chung-Ang University, Dongjak-Gu, Seoul, Republic of Korea
- * E-mail: (Y-HK); (JB); (KL)
| | - Kangseok Lee
- Department of Life Science, Chung-Ang University, Dongjak-Gu, Seoul, Republic of Korea
- * E-mail: (Y-HK); (JB); (KL)
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Shin E, Jin H, Suh DS, Luo Y, Ha HJ, Kim TH, Hahn Y, Hyun S, Lee K, Bae J. An alternative miRISC targets a cancer-associated coding sequence mutation in FOXL2. EMBO J 2020; 39:e104719. [PMID: 33215742 PMCID: PMC7737606 DOI: 10.15252/embj.2020104719] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2020] [Revised: 08/28/2020] [Accepted: 09/06/2020] [Indexed: 12/16/2022] Open
Abstract
Recent evidence suggests that animal microRNAs (miRNAs) can target coding sequences (CDSs); however, the pathophysiological importance of such targeting remains unknown. Here, we show that a somatic heterozygous missense mutation (c.402C>G; p.C134W) in FOXL2, a feature shared by virtually all adult-type granulosa cell tumors (AGCTs), introduces a target site for miR-1236, which causes haploinsufficiency of the tumor-suppressor FOXL2. This miR-1236-mediated selective degradation of the variant FOXL2 mRNA is preferentially conducted by a distinct miRNA-loaded RNA-induced silencing complex (miRISC) directed by the Argonaute3 (AGO3) and DHX9 proteins. In both patients and a mouse model of AGCT, abundance of the inversely regulated variant FOXL2 with miR-1236 levels is highly correlated with malignant features of AGCT. Our study provides a molecular basis for understanding the conserved FOXL2 CDS mutation-mediated etiology of AGCT, revealing the existence of a previously unidentified mechanism of miRNA-targeting disease-associated mutations in the CDS by forming a non-canonical miRISC.
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Affiliation(s)
| | - Hanyong Jin
- Department of Life Science, Chung-Ang University, Seoul, Korea
| | - Dae-Shik Suh
- Department of Obstetrics and Gynecology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
| | - Yongyang Luo
- School of Pharmacy, Chung-Ang University, Seoul, Korea
| | - Hye-Jeong Ha
- School of Pharmacy, Chung-Ang University, Seoul, Korea
| | - Tae Heon Kim
- Department of Pathology, Bundang CHA Hospital, CHA University, Seongnam, Korea
| | - Yoonsoo Hahn
- Department of Life Science, Chung-Ang University, Seoul, Korea
| | - Seogang Hyun
- Department of Life Science, Chung-Ang University, Seoul, Korea
| | - Kangseok Lee
- Department of Life Science, Chung-Ang University, Seoul, Korea
| | - Jeehyeon Bae
- School of Pharmacy, Chung-Ang University, Seoul, Korea
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The coordinated action of RNase III and RNase G controls enolase expression in response to oxygen availability in Escherichia coli. Sci Rep 2019; 9:17257. [PMID: 31754158 PMCID: PMC6872547 DOI: 10.1038/s41598-019-53883-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Accepted: 10/09/2019] [Indexed: 01/25/2023] Open
Abstract
Rapid modulation of RNA function by endoribonucleases during physiological responses to environmental changes is known to be an effective bacterial biochemical adaptation. We report a molecular mechanism underlying the regulation of enolase (eno) expression by two endoribonucleases, RNase G and RNase III, the expression levels of which are modulated by oxygen availability in Escherichia coli. Analyses of transcriptional eno-cat fusion constructs strongly suggested the existence of cis-acting elements in the eno 5' untranslated region that respond to RNase III and RNase G cellular concentrations. Primer extension and S1 nuclease mapping analyses of eno mRNA in vivo identified three eno mRNA transcripts that are generated in a manner dependent on RNase III expression, one of which was found to accumulate in rng-deleted cells. Moreover, our data suggested that RNase III-mediated cleavage of primary eno mRNA transcripts enhanced Eno protein production, a process that involved putative cis-antisense RNA. We found that decreased RNase G protein abundance coincided with enhanced RNase III expression in E. coli grown anaerobically, leading to enhanced eno expression. Thereby, this posttranscriptional up-regulation of eno expression helps E. coli cells adjust their physiological reactions to oxygen-deficient metabolic modes. Our results revealed a molecular network of coordinated endoribonuclease activity that post-transcriptionally modulates the expression of Eno, a key enzyme in glycolysis.
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