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Mittal P, Sinha AK, Pandiyan A, Kumari L, Ray MK, Pavankumar TL. A type II toxin-antitoxin system is responsible for the cell death at low temperature in Pseudomonas syringae Lz4W lacking RNase R. J Biol Chem 2024; 300:107600. [PMID: 39059490 PMCID: PMC11375266 DOI: 10.1016/j.jbc.2024.107600] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2024] [Revised: 06/17/2024] [Accepted: 07/12/2024] [Indexed: 07/28/2024] Open
Abstract
RNase R (encoded by the rnr gene) is a highly processive 3' → 5' exoribonuclease essential for the growth of the psychrotrophic bacterium Pseudomonas syringae Lz4W at low temperature. The cell death of a rnr deletion mutant at low temperature has been previously attributed to processing defects in 16S rRNA, defective ribosomal assembly, and inefficient protein synthesis. We recently showed that RNase R is required to protect P. syringae Lz4W from DNA damage and oxidative stress, independent of its exoribonuclease activity. Here, we show that the processing defect in 16S rRNA does not cause cell death of the rnr mutant of P. syringae at low temperature. Our results demonstrate that the rnr mutant of P. syringae Lz4W, complemented with a RNase R deficient in exoribonuclease function (RNase RD284A), is defective in 16S rRNA processing but can grow at 4 °C. This suggested that the processing defect in ribosomal RNAs is not a cause of the cold sensitivity of the rnr mutant. We further show that the rnr mutant accumulates copies of the indigenous plasmid pLz4W that bears a type II toxin-antitoxin (TA) system (P. syringae antitoxin-P. syringae toxin). This phenotype was rescued by overexpressing antitoxin psA in the rnr mutant, suggesting that activation of the type II TA system leads to cold sensitivity of the rnr mutant of P. syringae Lz4W. Here, we report a previously unknown functional relationship between the cold sensitivity of the rnr mutant and a type II TA system in P. syringae Lz4W.
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Affiliation(s)
- Pragya Mittal
- Centre for Cellular and Molecular Biology (CCMB), Council of Scientific and Industrial Research (CSIR), Hyderabad, India; Celtic Renewables Ltd, Edinburgh Napier University, Edinburgh, UK.
| | - Anurag K Sinha
- Centre for Cellular and Molecular Biology (CCMB), Council of Scientific and Industrial Research (CSIR), Hyderabad, India; National Food Institute, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Apuratha Pandiyan
- Centre for Cellular and Molecular Biology (CCMB), Council of Scientific and Industrial Research (CSIR), Hyderabad, India; Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Punjab, India
| | - Leela Kumari
- Centre for Cellular and Molecular Biology (CCMB), Council of Scientific and Industrial Research (CSIR), Hyderabad, India
| | - Malay K Ray
- Centre for Cellular and Molecular Biology (CCMB), Council of Scientific and Industrial Research (CSIR), Hyderabad, India
| | - Theetha L Pavankumar
- Centre for Cellular and Molecular Biology (CCMB), Council of Scientific and Industrial Research (CSIR), Hyderabad, India; Department of Microbiology and Molecular Genetics, University of California, Davis, California, USA; Department of Molecular and Cellular Biology, University of California, Davis, California, USA.
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Pavankumar TL. RNase R vs. PNPase: selecting the best-suited exoribonuclease for environmental adaptation. Extremophiles 2024; 28:35. [PMID: 39052080 DOI: 10.1007/s00792-024-01350-6] [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: 02/28/2024] [Accepted: 07/08/2024] [Indexed: 07/27/2024]
Abstract
3' → 5' exoribonucleases play a critical role in many aspects of RNA metabolism. RNase R, PNPase, and RNase II are the major contributors to RNA processing, maturation, and quality control in bacteria. Bacteria don't seem to have dedicated RNA degradation machineries to process different classes of RNAs. Under different environmental and physiological conditions, their roles can be redundant and sometimes overlapping. Here, I discuss why PNPase and RNase R may have switched their physiological roles in some bacterial species to adapt to environmental conditions, despite being biochemically distinct exoribonucleases.
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Affiliation(s)
- Theetha L Pavankumar
- Department of Microbiology and Molecular Genetics, and Department of Molecular and Cellular Biology, University of California, Davis, CA, 95616, USA.
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3
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Hussain A, Ray MK. Role of DEAD-box RNA helicases in low-temperature adapted growth of Antarctic Pseudomonas syringae Lz4W. Microbiol Spectr 2024; 12:e0433522. [PMID: 38014988 PMCID: PMC10783127 DOI: 10.1128/spectrum.04335-22] [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: 11/06/2022] [Accepted: 10/16/2023] [Indexed: 11/29/2023] Open
Abstract
IMPORTANCE RNA metabolism is important as RNA acts as a link between genomic information and functional biomolecules, thereby playing a critical role in cellular response to environment. We investigated the role of DEAD-box RNA helicases in low-temperature adapted growth of P. syringae, as this group of enzymes play an essential role in modulation of RNA secondary structures. This is the first report on the assessment of all major DEAD-box RNA helicases in any Antarctic bacterium. Of the five RNA helicases, three (srmB, csdA, and dbpA) are important for the growth of the Antarctic P. syringae at low temperature. However, the requisite role of dbpA and the indispensable requirement of csdA for low-temperature adapted growth are a novel finding of this study. Growth analysis of combinatorial deletion strains was performed to understand the functional interaction among helicase genes. Similarly, genetic complementation of RNA helicase mutants was conducted for identification of gene redundancy in P. syringae.
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Affiliation(s)
- Ashaq Hussain
- Centre for Cellular and Molecular Biology, Hyderabad, Telangana, India
| | - Malay Kumar Ray
- Centre for Cellular and Molecular Biology, Hyderabad, Telangana, India
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Mittal P, Sipani R, Pandiyan A, Sulthana S, Sinha AK, Hussain A, Ray MK, Pavankumar TL. Exoribonuclease RNase R protects Antarctic Pseudomonas syringae Lz4W from DNA damage and oxidative stress. Appl Environ Microbiol 2023; 89:e0116823. [PMID: 37905926 PMCID: PMC10686088 DOI: 10.1128/aem.01168-23] [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: 07/10/2023] [Accepted: 08/30/2023] [Indexed: 11/02/2023] Open
Abstract
IMPORTANCE Bacterial exoribonucleases play a crucial role in RNA maturation, degradation, quality control, and turnover. In this study, we have uncovered a previously unknown role of 3'-5' exoribonuclease RNase R of Pseudomonas syringae Lz4W in DNA damage and oxidative stress response. Here, we show that neither the exoribonuclease function of RNase R nor its association with the RNA degradosome complex is essential for this function. Interestingly, in P. syringae Lz4W, hydrolytic RNase R exhibits physiological roles similar to phosphorolytic 3'-5' exoribonuclease PNPase of E. coli. Our data suggest that during the course of evolution, mesophilic E. coli and psychrotrophic P. syringae have apparently swapped these exoribonucleases to adapt to their respective environmental growth conditions.
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Affiliation(s)
- Pragya Mittal
- Centre for Cellular and Molecular Biology (CCMB), Council of Scientific and Industrial Research (CSIR), Hyderabad, India
| | - Rashmi Sipani
- Centre for Cellular and Molecular Biology (CCMB), Council of Scientific and Industrial Research (CSIR), Hyderabad, India
| | - Apuratha Pandiyan
- Centre for Cellular and Molecular Biology (CCMB), Council of Scientific and Industrial Research (CSIR), Hyderabad, India
| | - Shaheen Sulthana
- Centre for Cellular and Molecular Biology (CCMB), Council of Scientific and Industrial Research (CSIR), Hyderabad, India
| | - Anurag K. Sinha
- Centre for Cellular and Molecular Biology (CCMB), Council of Scientific and Industrial Research (CSIR), Hyderabad, India
| | - Ashaq Hussain
- Centre for Cellular and Molecular Biology (CCMB), Council of Scientific and Industrial Research (CSIR), Hyderabad, India
| | - Malay K. Ray
- Centre for Cellular and Molecular Biology (CCMB), Council of Scientific and Industrial Research (CSIR), Hyderabad, India
| | - Theetha L. Pavankumar
- Centre for Cellular and Molecular Biology (CCMB), Council of Scientific and Industrial Research (CSIR), Hyderabad, India
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5
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Hussain A, Ray MK. Functional activity of E. coli RNase R in the Antarctic Pseudomonas syringae Lz4W. J Genet Eng Biotechnol 2023; 21:101. [PMID: 37843651 PMCID: PMC10579198 DOI: 10.1186/s43141-023-00553-2] [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: 09/09/2022] [Accepted: 09/20/2023] [Indexed: 10/17/2023]
Abstract
BACKGROUND In Antarctic P. syringae RNase R play an essential role in the processing of 16S and 5S rRNA, thereby playing an important role in cold-adapted growth of the bacterium. This study is focused on deciphering the in vivo functional activity of mesophilic exoribonuclease R and its catalytic domain (RNB) in an evolutionary distant psychrophilic bacterium Pseudomonas syringae Lz4W. RESULTS Our results confirm that E. coli RNase R complemented the physiological functions of the psychrophilic bacterium P. syringae RNase R and rescued the cold-sensitive phenotype of Pseudomonas syringae ∆rnr mutant. More importantly, the catalytic domain (RNB) of the E. coli RNase R is also capable of alleviating the cold-sensitive growth defects of ∆rnr mutant as seen with the catalytic domain (RNB) of the P. syringae enzyme. The Catalytic domain of E. coli RNase R was less efficient than the Catalytic domain of P. syringae RNase R in rescuing the cold-sensitive growth of ∆rnr mutant at 4°C, as the ∆rnr expressing the RNBEc (catalytic domain of E. coli RNase R) displayed longer lag phase than the RNBPs (Catalytic domain of P. syringae RNase R) complemented ∆rnr mutant at 4°C. Altogether it appears that the E. coli RNase R and P. syringae RNase R are functionally exchangeable for the growth requirements of P. syringae at low temperature (4°C). Our results also confirm that in P. syringae the requirement of RNase R for supporting the growth at 4°C is independent of the degradosomal complex. CONCLUSION E. coli RNase R (RNase REc) rescues the cold-sensitive phenotype of the P. syringae Δrnr mutant. Similarly, the catalytic domain of E. coli RNase R (RNBEc) is also capable of supporting the growth of Δrnr mutant at low temperatures. These findings have a vast scope in the design and development of low-temperature-based expression systems.
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Affiliation(s)
- Ashaq Hussain
- Centre for Cellular and Molecular Biology, Hyderabad, India.
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Costa SM, Saramago M, Matos RG, Arraiano CM, Viegas SC. How hydrolytic exoribonucleases impact human disease: Two sides of the same story. FEBS Open Bio 2022. [PMID: 35247037 DOI: 10.1002/2211-5463.13392] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 02/16/2022] [Accepted: 03/03/2022] [Indexed: 11/05/2022] Open
Abstract
RNAs are extremely important molecules inside the cell which perform many different functions. For example, messenger RNAs, transfer RNAs, and ribosomal RNAs are involved in protein synthesis, whereas non-coding RNAs have numerous regulatory roles. Ribonucleases are the enzymes responsible for the processing and degradation of all types of RNAs, having multiple roles in every aspect of RNA metabolism. However, the involvement of RNases in disease is still not well understood. This review focuses on the involvement of the RNase II/RNB family of 3'-5' exoribonucleases in human disease. This can be attributed to direct effects, whereby mutations in the eukaryotic enzymes of this family (Dis3 (or Rrp44), Dis3L1 (or Dis3L), and Dis3L2) are associated with a disease, or indirect effects, whereby mutations in the prokaryotic counterparts of RNase II/RNB family (RNase II and/or RNase R) affect the physiology and virulence of several human pathogens. In this review, we will compare the structural and biochemical characteristics of the members of the RNase II/RNB family of enzymes. The outcomes of mutations impacting enzymatic function will be revisited, in terms of both the direct and indirect effects on disease. Furthermore, we also describe the SARS-CoV-2 viral exoribonuclease and its importance to combat COVID-19 pandemic. As a result, RNases may be a good therapeutic target to reduce bacterial and viral pathogenicity. These are the two perspectives on RNase II/RNB family enzymes that will be presented in this review.
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Affiliation(s)
- Susana M Costa
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, EAN, 2780-157, Oeiras, Portugal
| | - Margarida Saramago
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, EAN, 2780-157, Oeiras, Portugal
| | - Rute G Matos
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, EAN, 2780-157, Oeiras, Portugal
| | - Cecília M Arraiano
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, EAN, 2780-157, Oeiras, Portugal
| | - Sandra C Viegas
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, EAN, 2780-157, Oeiras, Portugal
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Roy S, Mittal P, Tayi L, Bondada S, Ray MK, Patel HK, Sonti RV. Xanthomonas oryzae pv. oryzae Exoribonuclease R Is Required for Complete Virulence in Rice, Optimal Motility, and Growth Under Stress. PHYTOPATHOLOGY 2022; 112:501-510. [PMID: 34384245 DOI: 10.1094/phyto-07-21-0310-r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Exoribonuclease R (RNase R) is a 3' hydrolytic exoribonuclease that can degrade structured RNA. Mutation in RNase R affects virulence of certain human pathogenic bacteria. The aim of this study was to determine whether RNase R is necessary for virulence of the phytopathogen that causes bacterial blight in rice, Xanthomonas oryzae pv. oryzae (Xoo). In silico analysis has indicated that RNase R is highly conserved among various xanthomonads. Amino acid sequence alignment of Xoo RNase R with RNase R from various taxa indicated that Xoo RNase R clustered with RNase R of order Xanthomonadales. To study its role in virulence, we generated a gene disruption mutant of Xoo RNase R. The Xoo rnr- mutant is moderately virulence deficient, and the complementing strain (rnr-/pHM1::rnr) rescued the virulence deficiency of the mutant. We investigated swimming and swarming motilities in both nutrient-deficient minimal media and nutrient-optimal media. We observed that RNase R mutation has adversely affected the swimming and swarming motilities of Xoo in optimal media. However, in nutrient-deficient media only swimming motility was noticeably affected. Growth curves in optimal media at suboptimal temperature (15°C cold stress) indicate that the Xoo rnr- mutant grows more slowly than the Xoo wild type and complementing strain (rnr-/pHM1::rnr). Given these findings, we report for the first time that RNase R function is necessary for complete virulence of Xoo in rice. It is also important for motility of Xoo in media and for growth of Xoo at suboptimal temperature.
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Affiliation(s)
- Sharmila Roy
- CSIR-Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad, Telangana State, India 500007
| | - Pragya Mittal
- MRC Human Genetics Unit, University of Edinburgh, Crewe Road South, Edinburgh, UK, EH4 2XU
| | - Lavanya Tayi
- Center for Plant Molecular Biology, Osmania University, Tarnaka, Hyderabad, Telangana State, India 500007
| | - Sahitya Bondada
- CSIR-Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad, Telangana State, India 500007
| | - Malay K Ray
- CSIR-Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad, Telangana State, India 500007
| | - Hitendra K Patel
- CSIR-Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad, Telangana State, India 500007
| | - Ramesh V Sonti
- Indian Institute of Science Education and Research, Tirupati, Andhra Pradesh, India 517507
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Hsu TY, Hsu LN, Chen SY, Juang BT. MUT-7 Provides Molecular Insight into the Werner Syndrome Exonuclease. Cells 2021; 10:cells10123457. [PMID: 34943966 PMCID: PMC8700014 DOI: 10.3390/cells10123457] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 12/01/2021] [Accepted: 12/05/2021] [Indexed: 11/24/2022] Open
Abstract
Werner syndrome (WS) is a rare recessive genetic disease characterized by premature aging. Individuals with this disorder develop normally during childhood, but their physiological conditions exacerbate the aging process in late adolescence. WS is caused by mutation of the human WS gene (WRN), which encodes two main domains, a 3′-5′ exonuclease and a 3′-5′ helicase. Caenorhabditis elegans expresses human WRN orthologs as two different proteins: MUT-7, which has a 3′-5′ exonuclease domain, and C. elegans WRN-1 (CeWRN-1), which has only helicase domains. These unique proteins dynamically regulate olfactory memory in C. elegans, providing insight into the molecular roles of WRN domains in humans. In this review, we specifically focus on characterizing the function of MUT-7 in small interfering RNA (siRNA) synthesis in the cytoplasm and the roles of siRNA in directing nuclear CeWRN-1 loading onto a heterochromatin complex to induce negative feedback regulation. Further studies on the different contributions of the 3′-5′ exonuclease and helicase domains in the molecular mechanism will provide clues to the accelerated aging processes in WS.
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Affiliation(s)
- Tsung-Yuan Hsu
- Department of Biological Science and Technology, National Yang Ming Chiao Tung University, Hsinchu 300, Taiwan;
- Department of Cell and Tissue Biology, University of California, 513 Parnassus, San Francisco, CA 94143, USA
| | - Ling-Nung Hsu
- Occupational Safety and Health Office, Fu Jen Catholic University Hospital, New Taipei City 243, Taiwan;
| | - Shih-Yu Chen
- Institute of Biomedical Sciences, Academia Sinica, Taipei 115, Taiwan;
| | - Bi-Tzen Juang
- Department of Biological Science and Technology, National Yang Ming Chiao Tung University, Hsinchu 300, Taiwan;
- Center for Intelligent Drug Systems and Smart Bio-Devices (IDS2B), National Chiao Tung University, Hsinchu 300, Taiwan
- Correspondence:
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Apura P, Gonçalves LG, Viegas SC, Arraiano CM. The world of ribonucleases from pseudomonads: a short trip through the main features and singularities. Microb Biotechnol 2021; 14:2316-2333. [PMID: 34427985 PMCID: PMC8601179 DOI: 10.1111/1751-7915.13890] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Accepted: 06/30/2021] [Indexed: 11/27/2022] Open
Abstract
The development of synthetic biology has brought an unprecedented increase in the number molecular tools applicable into a microbial chassis. The exploration of such tools into different bacteria revealed not only the challenges of context dependency of biological functions but also the complexity and diversity of regulatory layers in bacterial cells. Most of the standardized genetic tools and principles/functions have been mostly based on model microorganisms, namely Escherichia coli. In contrast, the non-model pseudomonads lack a deeper understanding of their regulatory layers and have limited molecular tools. They are resistant pathogens and promising alternative bacterial chassis, making them attractive targets for further studies. Ribonucleases (RNases) are key players in the post-transcriptional control of gene expression by degrading or processing the RNA molecules in the cell. These enzymes act according to the cellular requirements and can also be seen as the recyclers of ribonucleotides, allowing a continuous input of these cellular resources. This makes these post-transcriptional regulators perfect candidates to regulate microbial physiology. This review summarizes the current knowledge and unique properties of ribonucleases in the world of pseudomonads, taking into account genomic context analysis, biological function and strategies to use ribonucleases to improve biotechnological processes.
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Affiliation(s)
- Patrícia Apura
- Instituto de Tecnologia Química e Biológica António XavierUniversidade Nova de LisboaAv. da República, EANOeiras2780‐157Portugal
| | - Luis G. Gonçalves
- Instituto de Tecnologia Química e Biológica António XavierUniversidade Nova de LisboaAv. da República, EANOeiras2780‐157Portugal
| | - Sandra C. Viegas
- Instituto de Tecnologia Química e Biológica António XavierUniversidade Nova de LisboaAv. da República, EANOeiras2780‐157Portugal
| | - Cecília M. Arraiano
- Instituto de Tecnologia Química e Biológica António XavierUniversidade Nova de LisboaAv. da República, EANOeiras2780‐157Portugal
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Pavankumar TL, Mittal P, Hallsworth JE. Molecular insights into the ecology of a psychrotolerant
Pseudomonas syringae. Environ Microbiol 2020; 23:3665-3681. [DOI: 10.1111/1462-2920.15304] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 11/01/2020] [Accepted: 11/03/2020] [Indexed: 02/06/2023]
Affiliation(s)
- Theetha L. Pavankumar
- Department of Microbiology and Molecular Genetics, Briggs Hall, One Shields Avenue University of California Davis CA USA
| | - Pragya Mittal
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine University of Edinburgh Crewe Road South, Edinburgh, EH42XU, Scotland UK
| | - John E. Hallsworth
- Institute for Global Food Security, School of Biological Sciences Queen's University Belfast 19 Chlorine Gardens, Belfast, BT9 5DL Northern Ireland UK
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Apura P, de Lorenzo V, Arraiano CM, Martínez-García E, Viegas SC. Ribonucleases control distinct traits of Pseudomonas putida lifestyle. Environ Microbiol 2020; 23:174-189. [PMID: 33089610 DOI: 10.1111/1462-2920.15291] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 09/21/2020] [Accepted: 10/19/2020] [Indexed: 11/28/2022]
Abstract
The role of archetypal ribonucleases (RNases) in the physiology and stress endurance of the soil bacterium and metabolic engineering platform Pseudomonas putida KT2440 has been inspected. To this end, variants of this strain lacking each of the most important RNases were constructed. Each mutant lacked either one exoribonuclease (PNPase, RNase R) or one endoribonuclease (RNase E, RNase III, RNase G). The global physiological and metabolic costs of the absence of each of these enzymes were then analysed in terms of growth, motility and morphology. The effects of different oxidative chemicals that mimic the stresses endured by this microorganism in its natural habitats were studied as well. The results highlighted that each ribonuclease is specifically related with different traits of the environmental lifestyle that distinctively characterizes this microorganism. Interestingly, the physiological responses of P. putida to the absence of each enzyme diverged significantly from those known previously in Escherichia coli. This exposed not only species-specific regulatory functions for otherwise known RNase activities but also expanded the panoply of post-transcriptional adaptation devices that P. putida can make use of for facing hostile environments.
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Affiliation(s)
- Patrícia Apura
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Av. da República, EAN, 2780-157, Portugal
| | - Víctor de Lorenzo
- Systems Biology Program, Centro Nacional de Biotecnologia, CSIC, C/Darwin, 3 (Campus de Cantoblanco), Madrid, 28049, Spain
| | - Cecília M Arraiano
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Av. da República, EAN, 2780-157, Portugal
| | - Esteban Martínez-García
- Systems Biology Program, Centro Nacional de Biotecnologia, CSIC, C/Darwin, 3 (Campus de Cantoblanco), Madrid, 28049, Spain
| | - Sandra C Viegas
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Av. da República, EAN, 2780-157, Portugal
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Núñez-Montero K, Quezada-Solís D, Khalil ZG, Capon RJ, Andreote FD, Barrientos L. Genomic and Metabolomic Analysis of Antarctic Bacteria Revealed Culture and Elicitation Conditions for the Production of Antimicrobial Compounds. Biomolecules 2020; 10:E673. [PMID: 32349314 PMCID: PMC7277857 DOI: 10.3390/biom10050673] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 04/15/2020] [Accepted: 04/21/2020] [Indexed: 01/08/2023] Open
Abstract
Concern about finding new antibiotics against drug-resistant pathogens is increasing every year. Antarctic bacteria have been proposed as an unexplored source of bioactive metabolites; however, most biosynthetic gene clusters (BGCs) producing secondary metabolites remain silent under common culture conditions. Our work aimed to characterize elicitation conditions for the production of antibacterial secondary metabolites from 34 Antarctic bacterial strains based on MS/MS metabolomics and genome mining approaches. Bacterial strains were cultivated under different nutrient and elicitation conditions, including the addition of lipopolysaccharide (LPS), sodium nitroprusside (SNP), and coculture. Metabolomes were obtained by HPLC-QTOF-MS/MS and analyzed through molecular networking. Antibacterial activity was determined, and seven strains were selected for genome sequencing and analysis. Biosynthesis pathways were activated by all the elicitation treatments, which varies among strains and dependents of culture media. Increased antibacterial activity was observed for a few strains and addition of LPS was related with inhibition of Gram-negative pathogens. Antibiotic BGCs were found for all selected strains and the expressions of putative actinomycin, carotenoids, and bacillibactin were characterized by comparison of genomic and metabolomic data. This work established the use of promising new elicitors for bioprospection of Antarctic bacteria and highlights the importance of new "-omics" comparative approaches for drug discovery.
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Affiliation(s)
- Kattia Núñez-Montero
- Laboratory of Molecular Applied Biology, Center of Excellence in Translational Medicine, Universidad de La Frontera, Avenida Alemania 0458, Temuco 4810296, Chile; (K.N.-M.); (D.Q.-S.)
- Scientific and Technological Bioresource Nucleus (BIOREN), Universidad de La Frontera, Temuco 4811230, Chile
- Biotechnology Investigation Center, Department of Biology, Instituto Tecnológico de Costa Rica, Cartago 159-7050, Costa Rica
| | - Damián Quezada-Solís
- Laboratory of Molecular Applied Biology, Center of Excellence in Translational Medicine, Universidad de La Frontera, Avenida Alemania 0458, Temuco 4810296, Chile; (K.N.-M.); (D.Q.-S.)
| | - Zeinab G. Khalil
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD 4072, Australia; (Z.G.K.); (R.J.C.)
| | - Robert J. Capon
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD 4072, Australia; (Z.G.K.); (R.J.C.)
| | - Fernando D. Andreote
- Department of Soil Science, “Luiz de Queiroz” College of Agriculture, University of São Paulo, Piracicaba, SP 13418-900, Brazil;
| | - Leticia Barrientos
- Laboratory of Molecular Applied Biology, Center of Excellence in Translational Medicine, Universidad de La Frontera, Avenida Alemania 0458, Temuco 4810296, Chile; (K.N.-M.); (D.Q.-S.)
- Scientific and Technological Bioresource Nucleus (BIOREN), Universidad de La Frontera, Temuco 4811230, Chile
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13
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A Novel Cold-Adapted and Salt-Tolerant RNase R from Antarctic Sea-Ice Bacterium Psychrobacter sp. ANT206. Molecules 2019; 24:molecules24122229. [PMID: 31207974 PMCID: PMC6630635 DOI: 10.3390/molecules24122229] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Revised: 06/10/2019] [Accepted: 06/11/2019] [Indexed: 11/17/2022] Open
Abstract
A novel RNase R, psrnr, was cloned from the Antarctic bacterium Psychrobacter sp. ANT206 and expressed in Escherichia coli (E. coli). A bioinformatics analysis of the psrnr gene revealed that it contained an open reading frame of 2313 bp and encoded a protein (PsRNR) of 770 amino acids. Homology modeling indicated that PsRNR had reduced hydrogen bonds and salt bridges, which might be the main reason for the catalytic efficiency at low temperatures. A site directed mutation exhibited that His 667 in the active site was absolutely crucial for the enzyme catalysis. The recombinant PsRNR (rPsRNR) showed maximum activity at 30 °C and had thermal instability, suggesting that rPsRNR was a cold-adapted enzyme. Interestingly, rPsRNR displayed remarkable salt tolerance, remaining stable at 0.5-3.0 M NaCl. Furthermore, rPsRNR had a higher kcat value, contributing to its efficient catalytic activity at a low temperature. Overall, cold-adapted RNase R in this study was an excellent candidate for antimicrobial treatment.
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14
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Reis FP, Bárria C, Gomez‐Puertas P, Gomes CM, Arraiano CM. Identification of temperature‐sensitive mutations and characterization of thermolabile
RN
ase
II
variants. FEBS Lett 2018; 593:352-360. [DOI: 10.1002/1873-3468.13313] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Accepted: 11/12/2018] [Indexed: 01/06/2023]
Affiliation(s)
- Filipa P. Reis
- Instituto de Tecnologia Química e Biológica António Xavier Universidade Nova de Lisboa Oeiras Portugal
| | - Cátia Bárria
- Instituto de Tecnologia Química e Biológica António Xavier Universidade Nova de Lisboa Oeiras Portugal
| | - Paulino Gomez‐Puertas
- Centro de Biologia Molecular ‘Severo Ochoa’ (CSIC‐UAM) Campus Universidad Autonoma de Madrid Spain
| | - Cláudio M. Gomes
- Biosystems and Integrative Sciences Institute Faculdade de Ciências Universidade de Lisboa Portugal
- Departamento de Química e Bioquímica Universidade de Lisboa Portugal
| | - Cecília M. Arraiano
- Instituto de Tecnologia Química e Biológica António Xavier Universidade Nova de Lisboa Oeiras Portugal
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15
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Dos Santos RF, Quendera AP, Boavida S, Seixas AF, Arraiano CM, Andrade JM. Major 3'-5' Exoribonucleases in the Metabolism of Coding and Non-coding RNA. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2018; 159:101-155. [PMID: 30340785 DOI: 10.1016/bs.pmbts.2018.07.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
3'-5' exoribonucleases are key enzymes in the degradation of superfluous or aberrant RNAs and in the maturation of precursor RNAs into their functional forms. The major bacterial 3'-5' exoribonucleases responsible for both these activities are PNPase, RNase II and RNase R. These enzymes are of ancient nature with widespread distribution. In eukaryotes, PNPase and RNase II/RNase R enzymes can be found in the cytosol and in mitochondria and chloroplasts; RNase II/RNase R-like enzymes are also found in the nucleus. Humans express one PNPase (PNPT1) and three RNase II/RNase R family members (Dis3, Dis3L and Dis3L2). These enzymes take part in a multitude of RNA surveillance mechanisms that are critical for translation accuracy. Although active against a wide range of both coding and non-coding RNAs, the different 3'-5' exoribonucleases exhibit distinct substrate affinities. The latest studies on these RNA degradative enzymes have contributed to the identification of additional homologue proteins, the uncovering of novel RNA degradation pathways, and to a better comprehension of several disease-related processes and response to stress, amongst many other exciting findings. Here, we provide a comprehensive and up-to-date overview on the function, structure, regulation and substrate preference of the key 3'-5' exoribonucleases involved in RNA metabolism.
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Affiliation(s)
- Ricardo F Dos Santos
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Ana P Quendera
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Sofia Boavida
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - André F Seixas
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Cecília M Arraiano
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - José M Andrade
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal.
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16
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Zhen H, Krumins V, Fennell DE, Mainelis G. Analysis of airborne microbial communities using 16S ribosomal RNA: Potential bias due to air sampling stress. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 621:939-947. [PMID: 29079080 PMCID: PMC5805565 DOI: 10.1016/j.scitotenv.2017.10.154] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Revised: 10/11/2017] [Accepted: 10/15/2017] [Indexed: 05/16/2023]
Abstract
A limited number of studies have been conducted to analyze ribosomal RNA (rRNA, present in the ribosome) in bioaerosol samples to identify currently or potentially active airborne microbes, although its genomic counterpart, the rRNA gene (on the chromosome) has been frequently targeted for airborne microbial community analysis. A knowledge gap still exists regarding whether the bioaerosol rRNA abundances are affected by the bioaerosol collection process. We investigated the effect of air sampling stress on the measurement and characterization of 16S rRNA for bioaerosols in the laboratory and field experiments using quantitative polymerase chain reaction (qPCR) and high-throughput sequencing techniques. In a laboratory study, known quantities of freshly grown Escherichia coli cells were spiked onto the filter of a Button Aerosol Sampler and into liquids of BioSampler and SpinCon air samplers and then exposed to sampling stress when the samplers were operated for 2h. We found that the recovered cellular 16S rRNA abundance as determined by qPCR was dependent on sampler type. Further, two devices (Button Aerosol Sampler and BioSampler) that exhibited markedly different efficiency in preserving 16S rRNA were employed in an outdoor environment to collect bioaerosols simultaneously on eight days in two different seasons. The abundance of 16S rRNA in the outdoor air sample (1.3×106-4.9×107copies/m3) was about two orders of magnitude higher than that of 16S rRNA gene (6.9×103-1.5×105copies/m3). The 16S rRNA sequences revealed a different bacterial community compared with 16S rRNA gene-based results across all samples, and this difference depended on the sampling device. In addition, a number of bacterial taxa exhibited higher abundance in the 16S rRNA gene sequences than in 16S rRNA sequences, which suggests the potential activities of certain microbes in airborne phase. Overall, this study highlights the importance of sampling device selection when analyzing RNA in bioaerosols.
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Affiliation(s)
- Huajun Zhen
- Rutgers University, Department of Environmental Sciences, 14 College Farm Rd., New Brunswick, NJ 08901, United States
| | - Valdis Krumins
- Rutgers University, Department of Environmental Sciences, 14 College Farm Rd., New Brunswick, NJ 08901, United States
| | - Donna E Fennell
- Rutgers University, Department of Environmental Sciences, 14 College Farm Rd., New Brunswick, NJ 08901, United States
| | - Gediminas Mainelis
- Rutgers University, Department of Environmental Sciences, 14 College Farm Rd., New Brunswick, NJ 08901, United States.
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17
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Dubnau EJ, Carabetta VJ, Tanner AW, Miras M, Diethmaier C, Dubnau D. A protein complex supports the production of Spo0A-P and plays additional roles for biofilms and the K-state in Bacillus subtilis. Mol Microbiol 2016; 101:606-24. [PMID: 27501195 DOI: 10.1111/mmi.13411] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/01/2016] [Indexed: 01/19/2023]
Abstract
Bacillus subtilis can enter three developmental pathways to form spores, biofilms or K-state cells. The K-state confers competence for transformation and antibiotic tolerance. Transition into each of these states requires a stable protein complex formed by YlbF, YmcA and YaaT. We have reported that this complex acts in sporulation by accelerating the phosphorylation of the response regulator Spo0A. Phosphorelay acceleration was also predicted to explain their involvement in biofilm formation and the K-state. This view has been challenged in the case of biofilms, by the suggestion that the three proteins act in association with the mRNA degradation protein RNaseY (Rny) to destabilize the sinR transcript. Here, we reaffirm the roles of the three proteins in supporting the phosphorylation of Spo0A for all three developmental pathways and show that in their absence sinR mRNA is not stabilized. We demonstrate that the three proteins also play unknown Spo0A-P-independent roles in the expression of biofilm matrix and in the production of ComK, the master transcription factor for competence. Finally, we show that domesticated strains of B. subtilis carry a mutation in sigH, which influences the expression kinetics of the early spore gene spoIIG, thereby increasing the penetrance of the ylbF, ymcA and yaaT sporulation phenotypes.
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Affiliation(s)
- Eugenie J Dubnau
- Public Health Research Institute Center.,Department of Microbiology, Biochemistry and Molecular Genetics, New Jersey Medical School, Rutgers University, 225 Warren Street, Newark, NJ, 07103, USA
| | - Valerie J Carabetta
- Public Health Research Institute Center.,Department of Microbiology, Biochemistry and Molecular Genetics, New Jersey Medical School, Rutgers University, 225 Warren Street, Newark, NJ, 07103, USA
| | - Andrew W Tanner
- Department of Microbiology, Biochemistry and Molecular Genetics, New Jersey Medical School, Rutgers University, 225 Warren Street, Newark, NJ, 07103, USA
| | | | | | - David Dubnau
- Public Health Research Institute Center.,Department of Microbiology, Biochemistry and Molecular Genetics, New Jersey Medical School, Rutgers University, 225 Warren Street, Newark, NJ, 07103, USA
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18
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Hossain ST, Deutscher MP. Helicase Activity Plays a Crucial Role for RNase R Function in Vivo and for RNA Metabolism. J Biol Chem 2016; 291:9438-43. [PMID: 27022019 DOI: 10.1074/jbc.c116.726091] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Indexed: 11/06/2022] Open
Abstract
RNase R is a 3' to 5' hydrolytic exoribonuclease that has the unusual ability to digest highly structured RNA. The enzyme possesses an intrinsic, ATP-dependent RNA helicase activity that is essential in vitro for efficient nuclease activity against double-stranded RNA substrates, particularly at lower temperatures, with more stable RNA duplexes, and for duplexes with short 3' overhangs. Here, we inquired whether the helicase activity was also important for RNase R function in vivo and for RNA metabolism. We find that strains containing a helicase-deficient RNase R due to mutations in its ATP-binding Walker motifs exhibit growth defects at low temperatures. Most importantly, cells also lacking polynucleotide phosphorylase (PNPase), and dependent for growth on RNase R, grow extremely poorly at 34, 37, and 42 °C and do not grow at all at 31 °C. Northern analysis revealed that in these cells, fragments of 16S and 23S rRNA accumulate to high levels, leading to interference with ribosome maturation and ultimately to cell death. These findings indicate that the intrinsic helicase activity of RNase R is required for its proper functioning in vivo and for effective RNA metabolism.
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Affiliation(s)
- Sk Tofajjen Hossain
- From the Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Miami, Florida 33101
| | - Murray P Deutscher
- From the Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Miami, Florida 33101
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19
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DiChiara JM, Liu B, Figaro S, Condon C, Bechhofer DH. Mapping of internal monophosphate 5' ends of Bacillus subtilis messenger RNAs and ribosomal RNAs in wild-type and ribonuclease-mutant strains. Nucleic Acids Res 2016; 44:3373-89. [PMID: 26883633 PMCID: PMC4838370 DOI: 10.1093/nar/gkw073] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2015] [Accepted: 01/29/2016] [Indexed: 11/14/2022] Open
Abstract
The recent findings that the narrow-specificity endoribonuclease RNase III and the 5′ exonuclease RNase J1 are not essential in the Gram-positive model organism, Bacillus subtilis, facilitated a global analysis of internal 5′ ends that are generated or acted upon by these enzymes. An RNA-Seq protocol known as PARE (Parallel Analysis of RNA Ends) was used to capture 5′ monophosphorylated RNA ends in ribonuclease wild-type and mutant strains. Comparison of PARE peaks in strains with RNase III present or absent showed that, in addition to its well-known role in ribosomal (rRNA) processing, many coding sequences and intergenic regions appeared to be direct targets of RNase III. These target sites were, in most cases, not associated with a known antisense RNA. The PARE analysis also revealed an accumulation of 3′-proximal peaks that correlated with the absence of RNase J1, confirming the importance of RNase J1 in degrading RNA fragments that contain the transcription terminator structure. A significant result from the PARE analysis was the discovery of an endonuclease cleavage just 2 nts downstream of the 16S rRNA 3′ end. This latter observation begins to answer, at least for B. subtilis, a long-standing question on the exonucleolytic versus endonucleolytic nature of 16S rRNA maturation.
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Affiliation(s)
- Jeanne M DiChiara
- Department of Pharmacology and Systems Therapeutics, Icahn School of Medicine at Mount Sinai, Box 1603, 1 Gustave L. Levy Place, New York, NY 10029, USA
| | - Bo Liu
- Department of Pharmacology and Systems Therapeutics, Icahn School of Medicine at Mount Sinai, Box 1603, 1 Gustave L. Levy Place, New York, NY 10029, USA
| | - Sabine Figaro
- CNRS UMR8261 (affiliated with Université Paris Diderot, Sorbonne Paris Cité), Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005 Paris, France
| | - Ciarán Condon
- CNRS UMR8261 (affiliated with Université Paris Diderot, Sorbonne Paris Cité), Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005 Paris, France
| | - David H Bechhofer
- Department of Pharmacology and Systems Therapeutics, Icahn School of Medicine at Mount Sinai, Box 1603, 1 Gustave L. Levy Place, New York, NY 10029, USA
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20
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Briani F, Carzaniga T, Dehò G. Regulation and functions of bacterial PNPase. WILEY INTERDISCIPLINARY REVIEWS-RNA 2016; 7:241-58. [PMID: 26750178 DOI: 10.1002/wrna.1328] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Revised: 11/23/2015] [Accepted: 11/23/2015] [Indexed: 01/29/2023]
Abstract
Polynucleotide phosphorylase (PNPase) is an exoribonuclease that catalyzes the processive phosphorolytic degradation of RNA from the 3'-end. The enzyme catalyzes also the reverse reaction of polymerization of nucleoside diphosphates that has been implicated in the generation of heteropolymeric tails at the RNA 3'-end. The enzyme is widely conserved and plays a major role in RNA decay in both Gram-negative and Gram-positive bacteria. Moreover, it participates in maturation and quality control of stable RNA. PNPase autoregulates its own expression at post-transcriptional level through a complex mechanism that involves the endoribonuclease RNase III and translation control. The activity of PNPase is modulated in an intricate and still unclear manner by interactions with small molecules and recruitment in different multiprotein complexes. Not surprisingly, given the wide spectrum of PNPase substrates, PNPase-defective mutations in different bacterial species have pleiotropic effects and perturb the execution of genetic programs involving drastic changes in global gene expression such as biofilm formation, growth at suboptimal temperatures, and virulence.
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Affiliation(s)
- Federica Briani
- Dipartimento di Bioscienze, Università degli Studi di Milano, Milan, Italy
| | - Thomas Carzaniga
- Dipartimento di Bioscienze, Università degli Studi di Milano, Milan, Italy
| | - Gianni Dehò
- Dipartimento di Bioscienze, Università degli Studi di Milano, Milan, Italy
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21
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Hammarlöf DL, Bergman JM, Garmendia E, Hughes D. Turnover of mRNAs is one of the essential functions of RNase E. Mol Microbiol 2015; 98:34-45. [PMID: 26094815 DOI: 10.1111/mmi.13100] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/18/2015] [Indexed: 11/28/2022]
Abstract
RNase E is an essential bacterial endoribonuclease with a central role in processing tRNAs and rRNA, and turning over mRNAs. Previous studies in strains carrying mutations in the rne structural gene have shown that tRNA processing is likely to be an essential function of RNase E but have not determined whether mRNA turnover is also an essential function. To address this we selected extragenic suppressors of temperature-sensitive mutations in rne that cause a large increase in mRNA half-life at the non-permissive temperature. Fifteen suppressors were mapped to three different loci: relBE (toxin-antitoxin system); vacB (RNase R); and rpsA (ribosomal protein S1). Each suppressor class has the potential to interact with mRNA and each restores wild-type levels of mRNA turnover but does not reverse the minor defects in tRNA and rRNA processing. RelE toxin is especially interesting because its only known activity is to cleave mRNAs in the ribosomal A-site. The relBE suppressor mutations increase transcription of relE, and controlled overexpression of RelE alone was sufficient to suppress the rne ts phenotype. Suppression increased turnover of some major mRNAs (tufA, ompA) but not all mRNAs. We propose that turnover of some mRNAs is one of the essential functions of RNase E.
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Affiliation(s)
- Disa L Hammarlöf
- Department of Medical Biochemistry and Microbiology, The Biomedical Center (Box 582), Uppsala University, Uppsala, SE-751 23, Sweden
| | - Jessica M Bergman
- Department of Medical Biochemistry and Microbiology, The Biomedical Center (Box 582), Uppsala University, Uppsala, SE-751 23, Sweden
| | - Eva Garmendia
- Department of Medical Biochemistry and Microbiology, The Biomedical Center (Box 582), Uppsala University, Uppsala, SE-751 23, Sweden
| | - Diarmaid Hughes
- Department of Medical Biochemistry and Microbiology, The Biomedical Center (Box 582), Uppsala University, Uppsala, SE-751 23, Sweden
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22
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Deutscher MP. How bacterial cells keep ribonucleases under control. FEMS Microbiol Rev 2015; 39:350-61. [PMID: 25878039 DOI: 10.1093/femsre/fuv012] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/02/2015] [Indexed: 11/13/2022] Open
Abstract
Ribonucleases (RNases) play an essential role in essentially every aspect of RNA metabolism, but they also can be destructive enzymes that need to be regulated to avoid unwanted degradation of RNA molecules. As a consequence, cells have evolved multiple strategies to protect RNAs against RNase action. They also utilize a variety of mechanisms to regulate the RNases themselves. These include post-transcriptional regulation, post-translational modification, trans-acting inhibitors, cellular localization, as well as others that are less well studied. In this review, I will briefly discuss how RNA molecules are protected and then examine in detail our current understanding of the mechanisms known to regulate individual RNases.
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Affiliation(s)
- Murray P Deutscher
- Biochemistry & Molecular Biology, University of Miami, Miami, FL 33136-6129, USA
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23
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Moreno R, Rojo F. Features of pseudomonads growing at low temperatures: another facet of their versatility. ENVIRONMENTAL MICROBIOLOGY REPORTS 2014; 6:417-426. [PMID: 25646532 DOI: 10.1111/1758-2229.12150] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Pseudomonads are a diverse and ecologically successful group of γ-proteobacteria present in many environments (terrestrial, freshwater and marine), either free living or associated with plants or animals. Their success is at least partly based on their ability to grow over a wide range of temperatures, their capacity to withstand different kinds of stress and their great metabolic versatility. Although the optimal growth temperature of pseudomonads is usually close to 25–30°C, many strains can also grow between 5°C and 10°C, and some of them even close to 0°C. Such low temperatures strongly affect the physicochemical properties of macromolecules, forcing cells to evolve traits that optimize growth and help them withstand cold-induced stresses such as increased levels of reactive oxygen species, reduced membrane fluidity and enzyme activity, cold-induced protein denaturation and the greater stability of DNA and RNA secondary structures. This review gathers the information available on the strategies used by pseudomonads to adapt to low temperature growth, and briefly describes some of the biotechnological applications that might benefit from cold-adapted bacterial strains and enzymes, e.g., biotransformation or bioremediation processes to be performed at low temperatures.
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24
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Vercruysse M, Köhrer C, Davies BW, Arnold MFF, Mekalanos JJ, RajBhandary UL, Walker GC. The highly conserved bacterial RNase YbeY is essential in Vibrio cholerae, playing a critical role in virulence, stress regulation, and RNA processing. PLoS Pathog 2014; 10:e1004175. [PMID: 24901994 PMCID: PMC4047096 DOI: 10.1371/journal.ppat.1004175] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Accepted: 04/24/2014] [Indexed: 11/18/2022] Open
Abstract
YbeY, a highly conserved protein, is an RNase in E. coli and plays key roles in both processing of the critical 3′ end of 16 S rRNA and in 70 S ribosome quality control under stress. These central roles account for YbeY's inclusion in the postulated minimal bacterial genome. However, YbeY is not essential in E. coli although loss of ybeY severely sensitizes it to multiple physiological stresses. Here, we show that YbeY is an essential endoribonuclease in Vibrio cholerae and is crucial for virulence, stress regulation, RNA processing and ribosome quality control, and is part of a core set of RNases essential in most representative pathogens. To understand its function, we analyzed the rRNA and ribosome profiles of a V. cholerae strain partially depleted for YbeY and other RNase mutants associated with 16 S rRNA processing; our results demonstrate that YbeY is also crucial for 16 S rRNA 3′ end maturation in V. cholerae and that its depletion impedes subunit assembly into 70 S ribosomes. YbeY's importance to V. cholerae pathogenesis was demonstrated by the complete loss of mice colonization and biofilm formation, reduced cholera toxin production, and altered expression levels of virulence-associated small RNAs of a V. cholerae strain partially depleted for YbeY. Notably, the ybeY genes of several distantly related pathogens can fully complement an E. coli ΔybeY strain under various stress conditions, demonstrating the high conservation of YbeY's activity in stress regulation. Taken together, this work provides the first comprehensive exploration of YbeY's physiological role in a human pathogen, showing its conserved function across species in essential cellular processes. Bacteria adapt and survive unfavorable environments by quickly changing their gene expression and physiology, for example as pathogens do during infection of host cells. Gene expression is often determined by RNA turnover, a balance between transcription and RNA decay carried out by multiple RNases. The recently identified RNase YbeY was shown in E. coli to participate in rRNA maturation and 70 S ribosome quality control, however YbeY's roles in other organisms and the extent of functional conservation is unknown. Here, we show that YbeY is an essential RNase in the pathogen Vibrio cholerae, critical for cell fitness and general stress tolerance. We demonstrate that YbeY is crucial for 16 S rRNA 3′ end maturation, assembly of functional 70 S ribosomes and ribosome quality control. Moreover, YbeY regulates virulence-associated small RNAs and its depletion leads to an overall reduction in pathogenesis, exemplified by significantly decreased biofilm formation, mouse colonization and cholera toxin production. We also show that YbeY belongs to a minimal core set of RNases essential in most representative pathogens. The multifaceted roles of YbeY in several essential cellular processes and its highly conserved function across bacterial species, suggest that YbeY could be an attractive new antimicrobial target.
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Affiliation(s)
- Maarten Vercruysse
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Caroline Köhrer
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Bryan W. Davies
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas, United States of America
| | - Markus F. F. Arnold
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - John J. Mekalanos
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, Massachussets, United States of America
| | - Uttam L. RajBhandary
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Graham C. Walker
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- * E-mail:
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25
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Matos RG, Bárria C, Moreira RN, Barahona S, Domingues S, Arraiano CM. The importance of proteins of the RNase II/RNB-family in pathogenic bacteria. Front Cell Infect Microbiol 2014; 4:68. [PMID: 24918089 PMCID: PMC4042491 DOI: 10.3389/fcimb.2014.00068] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Accepted: 05/09/2014] [Indexed: 11/13/2022] Open
Affiliation(s)
- Rute G Matos
- Control of Gene Expression Laboratory, Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa Oeiras, Portugal
| | - Cátia Bárria
- Control of Gene Expression Laboratory, Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa Oeiras, Portugal
| | - Ricardo N Moreira
- Control of Gene Expression Laboratory, Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa Oeiras, Portugal
| | - Susana Barahona
- Control of Gene Expression Laboratory, Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa Oeiras, Portugal
| | - Susana Domingues
- Control of Gene Expression Laboratory, Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa Oeiras, Portugal
| | - Cecília M Arraiano
- Control of Gene Expression Laboratory, Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa Oeiras, Portugal
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26
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Sinha AK, Pavankumar TL, Kamisetty S, Mittal P, Ray MK. Replication arrest is a major threat to growth at low temperature in Antarctic Pseudomonas syringae Lz4W. Mol Microbiol 2013; 89:792-810. [PMID: 23815755 DOI: 10.1111/mmi.12315] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/27/2013] [Indexed: 11/29/2022]
Abstract
Chromosomal damage was detected previously in the recBCD mutants of the Antarctic bacterium Pseudomonas syringae Lz4W, which accumulated linear chromosomal DNA leading to cell death and growth inhibition at 4°C. RecBCD protein generally repairs DNA double-strand breaks by RecA-dependent homologous recombination pathway. Here we show that ΔrecA mutant of P. syringae is not cold-sensitive. Significantly, inactivation of additional DNA repair genes ruvAB rescued the cold-sensitive phenotype of ΔrecBCD mutant. The ΔrecA and ΔruvAB mutants were UV-sensitive as expected. We propose that, at low temperature DNA replication encounters barriers leading to frequent replication fork (RF) arrest and fork reversal. RuvAB binds to the reversed RFs (RRFs) having Holliday junction-like structures and resolves them upon association with RuvC nuclease to cause linearization of the chromosome, a threat to cell survival. RecBCD prevents this by degrading the RRFs, and facilitates replication re-initiation. This model is consistent with our observation that low temperature-induced DNA lesions do not evoke SOS response in P. syringae. Additional studies show that two other repair genes, radA (encoding a RecA paralogue) and recF are not involved in providing cold resistance to the Antarctic bacterium.
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Affiliation(s)
- Anurag K Sinha
- Centre for Cellular and Molecular Biology Council of Scientific and Industrial Research, Uppal Road, Hyderabad, 500007, India
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Draft Genome Sequence of the Antarctic Psychrophilic Bacterium Pseudomonas syringae Strain Lz4W. GENOME ANNOUNCEMENTS 2013; 1:1/3/e00377-13. [PMID: 23788547 PMCID: PMC3707596 DOI: 10.1128/genomea.00377-13] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Abstract
The psychrophilic bacterium Pseudomonas syringae strain Lz4W was isolated from soil samples from Antarctica to decipher the mechanisms of low-temperature adaptation. We report here the 4.982-Mb draft genome sequence of P. syringae Lz4W. This sequence will provide insights into the genomic basis of the psychrophilicity of this bacterium.
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Reis FP, Pobre V, Silva IJ, Malecki M, Arraiano CM. The RNase II/RNB family of exoribonucleases: putting the 'Dis' in disease. WILEY INTERDISCIPLINARY REVIEWS-RNA 2013; 4:607-15. [PMID: 23776156 DOI: 10.1002/wrna.1180] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Revised: 05/03/2013] [Accepted: 05/14/2013] [Indexed: 12/21/2022]
Abstract
Important findings over the last years have shed new light onto the mechanistic details of RNA degradation by members of the RNase II/RNB family of exoribonucleases. Members of this family have been shown to be involved in growth, normal chloroplast biogenesis, mitotic control and cancer. Recently, different publications have linked human orthologs (Dis3 and Dis3L2) to important human diseases. This article describes the structural and biochemical characteristics of members of this family of enzymes, and the physiological implications that relate them with disease.
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Affiliation(s)
- Filipa P Reis
- Instituto de Tecnologia Química e Biológica-ITQB, Universidade Nova de Lisboa, Oeiras, Portugal
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Sulthana S, Deutscher MP. Multiple exoribonucleases catalyze maturation of the 3' terminus of 16S ribosomal RNA (rRNA). J Biol Chem 2013; 288:12574-9. [PMID: 23532845 DOI: 10.1074/jbc.c113.459172] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Processing of ribosomal RNA (rRNA) precursors is an important component of RNA metabolism in all cells. However, in no system have we yet identified all the RNases involved in this process. Here, we show that four 3'→5'-exoribonucleases, RNases II, R, and PH, and polynucleotide phosphorylase (PNPase), participate in maturation of the 3' end of 16S rRNA. In their absence, 16S precursor molecules with 33 extra 3'-nt accumulate; however, the presence of any one of the four RNases is sufficient to allow processing to occur, although with different efficiencies. Additionally, we find that in the absence of 3' maturation, 5' processing proceeds much less efficiently. Moreover, mutant 30S particles, containing immature 16S rRNA, form 70S ribosomes very poorly. These findings, together with the earlier discovery that RNases E and G are the 5'-processing enzymes, completes the catalogue of RNases involved in maturation of Escherichia coli 16S rRNA.
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Affiliation(s)
- Shaheen Sulthana
- Department of Biochemistry and Molecular Biology, Miller School of Medicine, University of Miami, Miami, Florida 33101, USA
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Conserved bacterial RNase YbeY plays key roles in 70S ribosome quality control and 16S rRNA maturation. Mol Cell 2012; 49:427-38. [PMID: 23273979 DOI: 10.1016/j.molcel.2012.11.025] [Citation(s) in RCA: 104] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2012] [Revised: 10/18/2012] [Accepted: 11/21/2012] [Indexed: 12/29/2022]
Abstract
Quality control of ribosomes is critical for cellular function since protein mistranslation leads to severe physiological consequences. We report evidence of a previously unrecognized ribosome quality control system in bacteria that operates at the level of 70S to remove defective ribosomes. YbeY, a previously unidentified endoribonuclease, and the exonuclease RNase R act together by a process mediated specifically by the 30S ribosomal subunit, to degrade defective 70S ribosomes but not properly matured 70S ribosomes or individual subunits. Furthermore, there is essentially no fully matured 16S rRNA in a ΔybeY mutant at 45°C, making YbeY the only endoribonuclease to be implicated in the critically important processing of the 16S rRNA 3' terminus. These key roles in ribosome quality control and maturation indicate why YbeY is a member of the minimal bacterial gene set and suggest that it could be a potential target for antibacterial drugs.
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Moreira RN, Domingues S, Viegas SC, Amblar M, Arraiano CM. Synergies between RNA degradation and trans-translation in Streptococcus pneumoniae: cross regulation and co-transcription of RNase R and SmpB. BMC Microbiol 2012; 12:268. [PMID: 23167513 PMCID: PMC3534368 DOI: 10.1186/1471-2180-12-268] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2012] [Accepted: 10/31/2012] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Ribonuclease R (RNase R) is an exoribonuclease that recognizes and degrades a wide range of RNA molecules. It is a stress-induced protein shown to be important for the establishment of virulence in several pathogenic bacteria. RNase R has also been implicated in the trans-translation process. Transfer-messenger RNA (tmRNA/SsrA RNA) and SmpB are the main effectors of trans-translation, an RNA and protein quality control system that resolves challenges associated with stalled ribosomes on non-stop mRNAs. Trans-translation has also been associated with deficiencies in stress-response mechanisms and pathogenicity. RESULTS In this work we study the expression of RNase R in the human pathogen Streptococcus pneumoniae and analyse the interplay of this enzyme with the main components of the trans-translation machinery (SmpB and tmRNA/SsrA). We show that RNase R is induced after a 37°C to 15°C temperature downshift and that its levels are dependent on SmpB. On the other hand, our results revealed a strong accumulation of the smpB transcript in the absence of RNase R at 15°C. Transcriptional analysis of the S. pneumoniae rnr gene demonstrated that it is co-transcribed with the flanking genes, secG and smpB. Transcription of these genes is driven from a promoter upstream of secG and the transcript is processed to yield mature independent mRNAs. This genetic organization seems to be a common feature of Gram positive bacteria, and the biological significance of this gene cluster is further discussed. CONCLUSIONS This study unravels an additional contribution of RNase R to the trans-translation system by demonstrating that smpB is regulated by this exoribonuclease. RNase R in turn, is shown to be under the control of SmpB. These proteins are therefore mutually dependent and cross-regulated. The data presented here shed light on the interactions between RNase R, trans-translation and cold-shock response in an important human pathogen.
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Affiliation(s)
- Ricardo N Moreira
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Av. da República, Oeiras 2780-157, Portugal
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rnr gene from the antarctic bacterium Pseudomonas syringae Lz4W, encoding a psychrophilic RNase R. Appl Environ Microbiol 2011; 77:7896-904. [PMID: 21926201 DOI: 10.1128/aem.05683-11] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
RNase R is a highly processive, hydrolytic 3'-5' exoribonuclease belonging to the RNB/RNR superfamily which plays significant roles in RNA metabolism in bacteria. The enzyme was observed to be essential for growth of the psychrophilic Antarctic bacterium Pseudomonas syringae Lz4W at a low temperature. We present results here pertaining to the biochemical properties of RNase R and the RNase R-encoding gene (rnr) locus from this bacterium. By cloning and expressing a His₆-tagged form of the P. syringae RNase R (RNase R(Ps)), we show that the enzyme is active at 0 to 4°C but exhibits optimum activity at ∼25°C. The enzyme is heat labile in nature, losing activity upon incubation at 37°C and above, a hallmark of many psychrophilic enzymes. The enzyme requires divalent cations (Mg²⁺ and Mn²⁺) for activity, and the activity is higher in 50 to 150 mM KCl when it largely remains as a monomer. On synthetic substrates, RNase R(Ps) exhibited maximum activity on poly(A) and poly(U) in preference over poly(G) and poly(C). The enzyme also degraded structured malE-malF RNA substrates. Analysis of the cleavage products shows that the enzyme, apart from releasing 5'-nucleotide monophosphates by the processive exoribonuclease activity, produces four-nucleotide end products, as opposed to two-nucleotide products, of RNA chain by Escherichia coli RNase R. Interestingly, three ribonucleotides (ATP, GTP, and CTP) inhibited the activity of RNase R(Ps) in vitro. The ability of the nonhydrolyzable ATP-γS to inhibit RNase R(Ps) activity suggests that nucleotide hydrolysis is not required for inhibition. This is the first report on the biochemical property of a psychrophilic RNase R from any bacterium.
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Fonseca P, Moreno R, Rojo F. Growth of Pseudomonas putida at low temperature: global transcriptomic and proteomic analyses. ENVIRONMENTAL MICROBIOLOGY REPORTS 2011; 3:329-339. [PMID: 23761279 DOI: 10.1111/j.1758-2229.2010.00229.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
In its natural habitats (soil, water and rhizosphere), Pseudomonas putida can suffer frequent and long-term changes in temperature that affect its growth and survival. Pseudomonas putida KT2440, a well-characterized model strain, grows optimally at 30°C but can proliferate at temperatures as low as 4°C. However, little information is available on the physiological changes that occur when P. putida grows at low temperatures. To investigate this area, the transcriptome and proteome profiles of cells exponentially growing in a complex medium at 10°C were compared with those of cells exponentially growing at 30°C. Low temperature modified the expression of at least 266 genes (some 5% of the genome). Many of the genes showing differential expression were involved in energy metabolism or in the transport and binding of substrates, although genes implicated in other cellular functions were also affected. Several changes seemed directed towards neutralizing problems created by low temperature, such as increased protein misfolding, the increased stability of DNA/RNA secondary structures, reduced membrane fluidity and a reduced growth rate. The present results improve our understanding of the P. putida lifestyle at low temperature, which may be relevant for its applications in bioremediation and in promotion of plant growth.
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Affiliation(s)
- Pilar Fonseca
- Departamento de Biotecnología Microbiana, Centro Nacional de Biotecnología, CSIC, Campus UAM, Cantoblanco, 28049 Madrid, Spain
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Abstract
Temperature downshift from 37 °C to 15 °C results in the exertion of cold shock response in Escherichia coli, which induces cold shock proteins, such as CsdA. Previously, we showed that the helicase activity of CsdA is critical for its function in the cold acclimation of cells and its primary role is mRNA degradation. Only RhlE (helicase), CspA (RNA chaperone) and RNase R (exoribonuclease) were found to complement the cold shock function of CsdA. RNase R has two independent activities, helicase and ribonuclease, only helicase being essential for the functional complementation of CsdA. Here, we discuss the significance of above findings as these emphasize the importance of the unwinding activity of cold-shock-inducible proteins in the RNA metabolism at low temperature, which may be different than that at 37 °C. It requires assistance of proteins to destabilize the secondary structures in mRNAs that are stabilized upon temperature downshift, hindering the activity of ribonucleases.
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Affiliation(s)
- Sangita Phadtare
- Department of Biochemistry, Robert Wood Johnson Medical School, Center for Advanced Biotechnology and Medicine, University of Medicine and Dentistry of New Jersey, Piscataway, NJ, USA.
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Ting L, Williams TJ, Cowley MJ, Lauro FM, Guilhaus M, Raftery MJ, Cavicchioli R. Cold adaptation in the marine bacterium, Sphingopyxis alaskensis, assessed using quantitative proteomics. Environ Microbiol 2011; 12:2658-76. [PMID: 20482592 DOI: 10.1111/j.1462-2920.2010.02235.x] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
The cold marine environment constitutes a large proportion of the Earth's biosphere. Sphingopyxis alaskensis was isolated as a numerically abundant bacterium from several cold marine locations, and has been extensively studied as a model marine bacterium. Recently, a metabolic labelling platform was developed to comprehensively identify and quantify proteins from S. alaskensis. The approach incorporated data normalization and statistical validation for the purpose of generating highly confident quantitative proteomics data. Using this approach, we determined quantitative differences between cells grown at 10°C (low temperature) and 30°C (high temperature). Cold adaptation was linked to specific aspects of gene expression: a dedicated protein-folding system using GroESL, DnaK, DnaJ, GrpE, SecB, ClpB and PPIase; polyhydroxyalkanoate-associated storage materials; a link between enzymes in fatty acid metabolism and energy generation; de novo synthesis of polyunsaturated fatty acids in the membrane and cell wall; inorganic phosphate ion transport by a phosphate import PstB homologue; TonB-dependent receptor and bacterioferritin in iron homeostasis; histidine, tryptophan and proline amino acid metabolism; and a large number of proteins without annotated functions. This study provides a new level of understanding on how important marine bacteria can adapt to compete effectively in cold marine environments. This study is also a benchmark for comparative proteomic analyses with other important marine bacteria and other cold-adapted organisms.
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Affiliation(s)
- Lily Ting
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, NSW 2052, Australia
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36
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Structure and Degradation Mechanisms of 3′ to 5′ Exoribonucleases. NUCLEIC ACIDS AND MOLECULAR BIOLOGY 2011. [DOI: 10.1007/978-3-642-21078-5_8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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Abstract
Bacterial stress responses provide them the opportunity to survive hostile environments, proliferate and potentially cause diseases in humans and animals. The way in which pathogenic bacteria interact with host immune cells triggers a complicated series of events that include rapid genetic re‐programming in response to the various host conditions encountered. Viewed in this light, the bacterial host‐cell induced stress response (HCISR) is similar to any other well‐characterized environmental stress to which bacteria must respond by upregulating a group of specific stress‐responsive genes. Post stress, bacteria must resume their pre‐stress genetic program, and, as a consequence, must degrade unnecessary stress responsive transcripts through RNA decay mechanisms. Further, there is a well‐established role for several ribonucleases in the cold shock response whereby they modulate the changing transcript landscape in response to the stress, and during acclimation and subsequent genetic re‐programming post stress. Recently, ribonucleases have been implicated as virulence‐associated factors in several notable Gram‐negative pathogens including, the yersiniae, the salmonellae, Helicobacter pylori, Shigella flexneri and Aeromonas hydrophila. This review will focus on the roles played by ribonucleases in bacterial virulence, other bacterial stress responses, and on their novel therapeutic applications.
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Affiliation(s)
- Abidat Lawal
- Department of Biology, Center for Bionanotechnology and Environmental Research, Texas Southern University, Houston, TX, USA
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38
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Hotto AM, Huston ZE, Stern DB. Overexpression of a natural chloroplast-encoded antisense RNA in tobacco destabilizes 5S rRNA and retards plant growth. BMC PLANT BIOLOGY 2010; 10:213. [PMID: 20920268 PMCID: PMC3017836 DOI: 10.1186/1471-2229-10-213] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2010] [Accepted: 09/29/2010] [Indexed: 05/19/2023]
Abstract
BACKGROUND The roles of non-coding RNAs in regulating gene expression have been extensively studied in both prokaryotes and eukaryotes, however few reports exist as to their roles in organellar gene regulation. Evidence for accumulation of natural antisense RNAs (asRNAs) in chloroplasts comes from the expressed sequence tag database and cDNA libraries, while functional data have been largely obtained from artificial asRNAs. In this study, we used Nicotiana tabacum to investigate the effect on sense strand transcripts of overexpressing a natural chloroplast asRNA, AS5, which is complementary to the region which encodes the 5S rRNA and tRNAArg. RESULTS AS5-overexpressing (AS5ox) plants obtained by chloroplast transformation exhibited slower growth and slightly pale green leaves. Analysis of AS5 transcripts revealed four distinct species in wild-type (WT) and AS5ox plants, and additional AS5ox-specific products. Of the corresponding sense strand transcripts, tRNAArg overaccumulated several-fold in transgenic plants whereas 5S rRNA was unaffected. However, run-on transcription showed that the 5S-trnR region was transcribed four-fold more in the AS5ox plants compared to WT, indicating that overexpression of AS5 was associated with decreased stability of 5S rRNA. In addition, polysome analysis of the transformants showed less 5S rRNA and rbcL mRNA associated with ribosomes. CONCLUSIONS Our results suggest that AS5 can modulate 5S rRNA levels, giving it the potential to affect Chloroplast translation and plant growth. More globally, overexpression of asRNAs via chloroplast transformation may be a useful strategy for defining their functions.
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MESH Headings
- Gene Expression Regulation, Plant
- Phenotype
- Plants, Genetically Modified/genetics
- Plants, Genetically Modified/metabolism
- RNA, Antisense/genetics
- RNA, Antisense/metabolism
- RNA, Chloroplast/genetics
- RNA, Chloroplast/metabolism
- RNA, Plant/genetics
- RNA, Plant/metabolism
- RNA, Ribosomal, 5S/genetics
- RNA, Ribosomal, 5S/metabolism
- RNA, Transfer, Arg/genetics
- RNA, Transfer, Arg/metabolism
- Nicotiana/genetics
- Nicotiana/growth & development
- Nicotiana/metabolism
- Transformation, Genetic
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Affiliation(s)
- Amber M Hotto
- Boyce Thompson Institute for Plant Research, Cornell University, Tower Rd., Ithaca, NY 14853, USA
| | - Zoe E Huston
- Riverdale High School, 9727 SW Terwilliger Blvd., Portland, OR 97219, USA
| | - David B Stern
- Boyce Thompson Institute for Plant Research, Cornell University, Tower Rd., Ithaca, NY 14853, USA
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Arraiano CM, Andrade JM, Domingues S, Guinote IB, Malecki M, Matos RG, Moreira RN, Pobre V, Reis FP, Saramago M, Silva IJ, Viegas SC. The critical role of RNA processing and degradation in the control of gene expression. FEMS Microbiol Rev 2010; 34:883-923. [PMID: 20659169 DOI: 10.1111/j.1574-6976.2010.00242.x] [Citation(s) in RCA: 254] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
The continuous degradation and synthesis of prokaryotic mRNAs not only give rise to the metabolic changes that are required as cells grow and divide but also rapid adaptation to new environmental conditions. In bacteria, RNAs can be degraded by mechanisms that act independently, but in parallel, and that target different sites with different efficiencies. The accessibility of sites for degradation depends on several factors, including RNA higher-order structure, protection by translating ribosomes and polyadenylation status. Furthermore, RNA degradation mechanisms have shown to be determinant for the post-transcriptional control of gene expression. RNases mediate the processing, decay and quality control of RNA. RNases can be divided into endonucleases that cleave the RNA internally or exonucleases that cleave the RNA from one of the extremities. Just in Escherichia coli there are >20 different RNases. RNase E is a single-strand-specific endonuclease critical for mRNA decay in E. coli. The enzyme interacts with the exonuclease polynucleotide phosphorylase (PNPase), enolase and RNA helicase B (RhlB) to form the degradosome. However, in Bacillus subtilis, this enzyme is absent, but it has other main endonucleases such as RNase J1 and RNase III. RNase III cleaves double-stranded RNA and family members are involved in RNA interference in eukaryotes. RNase II family members are ubiquitous exonucleases, and in eukaryotes, they can act as the catalytic subunit of the exosome. RNases act in different pathways to execute the maturation of rRNAs and tRNAs, and intervene in the decay of many different mRNAs and small noncoding RNAs. In general, RNases act as a global regulatory network extremely important for the regulation of RNA levels.
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Affiliation(s)
- Cecília M Arraiano
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Apartado 127, 2781-901 Oeiras, Portugal.
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40
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Sundareswaran VR, Singh AK, Dube S, Shivaji S. Aspartate aminotransferase is involved in cold adaptation in psychrophilic Pseudomonas syringae. Arch Microbiol 2010; 192:663-72. [DOI: 10.1007/s00203-010-0591-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2010] [Revised: 05/19/2010] [Accepted: 05/21/2010] [Indexed: 11/28/2022]
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Chen C, Deutscher MP. RNase R is a highly unstable protein regulated by growth phase and stress. RNA (NEW YORK, N.Y.) 2010; 16:667-672. [PMID: 20185542 PMCID: PMC2844616 DOI: 10.1261/rna.1981010] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2009] [Accepted: 01/12/2010] [Indexed: 05/28/2023]
Abstract
RNase R is an important exoribonuclease that participates in the degradation of structured RNAs in Escherichia coli. In earlier work, it was shown that RNase R levels increase dramatically under certain stress conditions, particularly during cold shock and stationary phase. However, the regulatory processes that lead to this elevation are not well understood. We show here that the increase in RNase R in stationary phase is unaffected by the global regulators, RpoS and (p)ppGpp, and that it occurs despite a major reduction in rnr message. Rather, we find that RNase R is a highly unstable protein in exponential phase, with a half-life of approximately 10 min, and that the protein is stabilized in stationary phase, leading to its relative increase. RNase R is also stabilized during cold shock and by growth in minimal medium, two other conditions that lead to its elevation. These data demonstrate that RNase R is subject to regulation by a novel, posttranslational mechanism that may have important implications for our complete understanding of RNA metabolism.
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Affiliation(s)
- Chenglu Chen
- Department of Biochemistry and Molecular Biology, Miller School of Medicine, University of Miami, Miami, Florida 33101, USA
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Pavankumar TL, Sinha AK, Ray MK. All three subunits of RecBCD enzyme are essential for DNA repair and low-temperature growth in the Antarctic Pseudomonas syringae Lz4W. PLoS One 2010; 5:e9412. [PMID: 20195537 PMCID: PMC2828478 DOI: 10.1371/journal.pone.0009412] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2009] [Accepted: 01/29/2010] [Indexed: 01/13/2023] Open
Abstract
Background The recD mutants of the Antarctic Pseudomonas syringae Lz4W are sensitive to DNA-damaging agents and fail to grow at 4°C. Generally, RecD associates with two other proteins (RecB and RecC) to produce RecBCD enzyme, which is involved in homologous recombination and DNA repair in many bacteria, including Escherichia coli. However, RecD is not essential for DNA repair, nor does its deletion cause any growth defects in E. coli. Hence, the assessment of the P. syringae RecBCD pathway was imperative. Methodology/Principal Findings Mutational analysis and genetic complementation studies were used to establish that the individual null-mutations of all three genes, recC, recB, and recD, or the deletion of whole recCBD operon of P. syringae, lead to growth inhibition at low temperature, and sensitivity to UV and mitomycin C. Viability of the mutant cells dropped drastically at 4°C, and the mutants accumulated linear chromosomal DNA and shorter DNA fragments in higher amounts compared to 22°C. Additional genetic data using the mutant RecBCD enzymes that were inactivated either in the ATPase active site of RecB (RecBK29Q) or RecD (RecDK229Q), or in the nuclease center of RecB (RecBD1118A and RecBΔnuc) suggested that, while the nuclease activity of RecB is not so critical in vivo, the ATP-dependent functions of both RecB and RecD are essential. Surprisingly, E. coli recBCD or recBC alone on plasmid could complement the defects of the ΔrecCBD strain of P. syringae. Conclusions/Significance All three subunits of the RecBCDPs enzyme are essential for DNA repair and growth of P. syringae at low temperatures (4°C). The RecD requirement is only a function of the RecBCD complex in the bacterium. The RecBCD pathway protects the Antarctic bacterium from cold-induced DNA damages, and is critically dependent on the helicase activities of both RecB and RecD subunits, but not on the nuclease of RecBCDPs enzyme.
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Affiliation(s)
- Theetha L. Pavankumar
- Centre for Cellular and Molecular Biology, Council of Scientific and Industrial Research, Hyderabad, India
| | - Anurag K. Sinha
- Centre for Cellular and Molecular Biology, Council of Scientific and Industrial Research, Hyderabad, India
| | - Malay K. Ray
- Centre for Cellular and Molecular Biology, Council of Scientific and Industrial Research, Hyderabad, India
- * E-mail:
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Söderberg MA, Cianciotto NP. Mediators of lipid A modification, RNA degradation, and central intermediary metabolism facilitate the growth of Legionella pneumophila at low temperatures. Curr Microbiol 2009; 60:59-65. [PMID: 19768502 DOI: 10.1007/s00284-009-9502-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2009] [Revised: 08/27/2009] [Accepted: 09/02/2009] [Indexed: 11/26/2022]
Abstract
Legionella pneumophila is an aquatic bacterium that is also the agent of Legionnaires' disease pneumonia. Since L. pneumophila is transmitted directly from the environment to the lung, it is important to understand how legionellae survive at low temperatures. To identify genes that are needed for L. pneumophila growth at low temperature, we screened a population of mutagenized legionellae for strains that are specifically impaired for growth at 17 degrees C. From the 7,400 mutants tested, 11 displayed defects ranging from ca. 10-fold to a complete inability to grow at the low temperature. PCR and sequence analysis were then utilized to identify the genes whose loss had compromised growth. The proteins thereby implicated in low-temperature growth included components of the type II secretion system (LspE, LspG, LspH), a lipid A biosynthetic enzyme (LpxP), a ribonuclease (RNAse R), an RNA helicase (CsdA/DeaD), TCA cycle enzymes (citrate synthase), enzymes linked to fatty acid (FadB) or amino acid (aspartate aminotransferase) catabolism, and two putative membrane proteins that were, based upon their sequences, unlike previously characterized proteins. Given the magnitude of their mutant's defect, the aspartate aminotransferase, RNA helicase, and one of the putative membrane proteins were the factors most critical for L. pneumophila low-temperature growth. Thus, L. pneumophila not only employs some of the same processes and factors as other bacteria do in order to survive at low temperatures (e.g., LpxP, CsdA), but it also appears to possess novel modes of cold adaptation.
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Affiliation(s)
- Maria A Söderberg
- Department of Microbiology and Immunology, Northwestern University Medical School, Chicago, IL 60611, USA
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Andrade JM, Hajnsdorf E, Régnier P, Arraiano CM. The poly(A)-dependent degradation pathway of rpsO mRNA is primarily mediated by RNase R. RNA (NEW YORK, N.Y.) 2009; 15:316-326. [PMID: 19103951 PMCID: PMC2648712 DOI: 10.1261/rna.1197309] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2008] [Accepted: 10/27/2008] [Indexed: 05/27/2023]
Abstract
Polyadenylation is an important factor controlling RNA degradation and RNA quality control mechanisms. In this report we demonstrate for the first time that RNase R has in vivo affinity for polyadenylated RNA and can be a key enzyme involved in poly(A) metabolism. RNase II and PNPase, two major RNA exonucleases present in Escherichia coli, could not account for all the poly(A)-dependent degradation of the rpsO mRNA. RNase II can remove the poly(A) tails but fails to degrade the mRNA as it cannot overcome the RNA termination hairpin, while PNPase plays only a modest role in this degradation. We now demonstrate that in the absence of RNase E, RNase R is the relevant factor in the poly(A)-dependent degradation of the rpsO mRNA. Moreover, we have found that the RNase R inactivation counteracts the extended degradation of this transcript observed in RNase II-deficient cells. Elongated rpsO transcripts harboring increasing poly(A) tails are specifically recognized by RNase R and strongly accumulate in the absence of this exonuclease. The 3' oligo(A) extension may stimulate the binding of RNase R, allowing the complete degradation of the mRNA, as RNase R is not susceptible to RNA secondary structures. Moreover, this regulation is shown to occur despite the presence of PNPase. Similar results were observed with the rpsT mRNA. This report shows that polyadenylation favors in vivo the RNase R-mediated pathways of RNA degradation.
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Affiliation(s)
- José M Andrade
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Oeiras, Portugal
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Deutscher MP. Maturation and degradation of ribosomal RNA in bacteria. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2009; 85:369-91. [PMID: 19215777 DOI: 10.1016/s0079-6603(08)00809-x] [Citation(s) in RCA: 136] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Ribosomal RNAs are the major components of ribosomes and are responsible for their catalytic activity. The three bacterial rRNAs (16S, 23S, and 5S) are cotranscribed as a single molecule that must be converted to the mature, functioning species through a series of nucleolytic processing events and base and sugar modifications that occur in the context of the assembling ribosome. One focus of this review is to examine the reactions that lead from the rRNA precursor to the mature species and to describe the ribonucleases (RNases) that carry out these processing reactions. rRNA, although usually stable in growing cells, also can be degraded if its assembly into ribosomes is aberrant or in response to certain stress conditions, such as starvation. The second focus of this review is to describe these degradative reactions, the RNases that carry them out, and the conditions that initiate the turnover process.
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Affiliation(s)
- Murray P Deutscher
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Miami, Florida, USA
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Andrade JM, Pobre V, Silva IJ, Domingues S, Arraiano CM. The role of 3'-5' exoribonucleases in RNA degradation. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2009; 85:187-229. [PMID: 19215773 DOI: 10.1016/s0079-6603(08)00805-2] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
RNA degradation is a major process controlling RNA levels and plays a central role in cell metabolism. From the labile messenger RNA to the more stable noncoding RNAs (mostly rRNA and tRNA, but also the expanding class of small regulatory RNAs) all molecules are eventually degraded. Elimination of superfluous transcripts includes RNAs whose expression is no longer required, but also the removal of defective RNAs. Consequently, RNA degradation is an inherent step in RNA quality control mechanisms. Furthermore, it contributes to the recycling of the nucleotide pool in the cell. Escherichia coli has eight 3'-5' exoribonucleases, which are involved in multiple RNA metabolic pathways. However, only four exoribonucleases appear to accomplish all RNA degradative activities: polynucleotide phosphorylase (PNPase), ribonuclease II (RNase II), RNase R, and oligoribonuclease. Here, we summarize the available information on the role of bacterial 3'-5' exoribonucleases in the degradation of different substrates, highlighting the most recent data that have contributed to the understanding of the diverse modes of operation of these degradative enzymes.
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Affiliation(s)
- José M Andrade
- Instituto de Tecnologia Quimica e Biologica, Universidade Nova de Lisboa, Qeiras, Portugal
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Evguenieva‐Hackenberg E, Klug G. Chapter 7 RNA Degradation in Archaea and Gram‐Negative Bacteria Different from Escherichia coli. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2009; 85:275-317. [DOI: 10.1016/s0079-6603(08)00807-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
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Abstract
RNase R is a processive 3'-5' exoribonuclease with a high degree of conservation in prokaryotes. Although some bacteria possess additional hydrolytic 3'-5' exoribonucleases such as RNase II, RNase R was found to be the only predicted one in the facultative intracellular pathogen Legionella pneumophila. This provided a unique opportunity to study the role of RNase R in the absence of an additional RNase with similar enzymatic activity. We investigated the role of RNase R in the biology of Legionella pneumophila under various conditions and performed gene expression profiling using microarrays. At optimal growth temperature, the loss of RNase R had no major consequence on bacterial growth and had a moderate impact on normal gene regulation. However, at a lower temperature, the loss of RNase R had a significant impact on bacterial growth and resulted in the accumulation of structured RNA degradation products. Concurrently, gene regulation was affected and specifically resulted in an increased expression of the competence regulon. Loss of the exoribonuclease activity of RNase R was sufficient to induce competence development, a genetically programmed process normally triggered as a response to environmental stimuli. The temperature-dependent expression of competence genes in the rnr mutant was found to be independent of previously identified competence regulators in Legionella pneumophila. We suggest that a physiological role of RNase R is to eliminate structured RNA molecules that are stabilized by low temperature, which in turn may affect regulatory networks, compromising adaptation to cold and thus resulting in decreased viability.
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Genomic analysis of the role of RNase R in the turnover of Pseudomonas putida mRNAs. J Bacteriol 2008; 190:6258-63. [PMID: 18641145 DOI: 10.1128/jb.00630-08] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
RNase R is a 3'-5' highly processive exoribonuclease that can digest RNAs with extensive secondary structure. We analyzed the global effect of eliminating RNase R on the Pseudomonas putida transcriptome and the expression of the rnr gene under diverse conditions. The absence of RNase R led to increased levels of many mRNAs, indicating that it plays an important role in mRNA turnover.
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Cold shock exoribonuclease R (VacB) is involved in Aeromonas hydrophila pathogenesis. J Bacteriol 2008; 190:3467-74. [PMID: 18344363 DOI: 10.1128/jb.00075-08] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In this study, we cloned and sequenced a virulence-associated gene (vacB) from a clinical isolate SSU of Aeromonas hydrophila. We identified this gene based on our recently annotated genome sequence of the environmental isolate ATCC 7966(T) of A. hydrophila and the vacB gene of Shigella flexneri. The A. hydrophila VacB protein contained 798 amino acid residues, had a molecular mass of 90.5 kDa, and exhibited an exoribonuclease (RNase R) activity. The RNase R of A. hydrophila was a cold-shock protein and was required for bacterial growth at low temperature. The vacB isogenic mutant, which we developed by homologous recombination using marker exchange mutagenesis, was unable to grow at 4 degrees C. In contrast, the wild-type (WT) A. hydrophila exhibited significant growth at this low temperature. Importantly, the vacB mutant was not defective in growth at 37 degrees C. The vacB mutant also exhibited reduced motility, and these growth and motility phenotype defects were restored after complementation of the vacB mutant. The A. hydrophila RNase R-lacking strain was found to be less virulent in a mouse lethality model (70% survival) when given by the intraperitoneal route at as two 50% lethal doses (LD(50)). On the other hand, the WT and complemented strains of A. hydrophila caused 80 to 90% of the mice to succumb to infection at the same LD(50) dose. Overall, this is the first report demonstrating the role of RNase R in modulating the expression of A. hydrophila virulence.
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