1
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He TT, Xu YF, Li X, Wang X, Li JY, Ou-Yang D, Cheng HS, Li HY, Qin J, Huang Y, Wang HY. A linear and circular dual-conformation noncoding RNA involved in oxidative stress tolerance in Bacillus altitudinis. Nat Commun 2023; 14:5722. [PMID: 37714854 PMCID: PMC10504365 DOI: 10.1038/s41467-023-41491-4] [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: 03/07/2023] [Accepted: 09/06/2023] [Indexed: 09/17/2023] Open
Abstract
Circular RNAs have been extensively studied in eukaryotes, but their presence and/or biological functionality in bacteria are unclear. Here, we show that a regulatory noncoding RNA (DucS) exists in both linear and circular conformation in Bacillus altitudinis. The linear forms promote B. altitudinis tolerance to H2O2 stress, partly through increased translation of a stress-responsive gene, htrA. The 3' end sequences of the linear forms are crucial for RNA circularization, and formation of circular forms can decrease the levels of the regulatory linear cognates. Bioinformatic analysis of available RNA-seq datasets from 30 bacterial species revealed multiple circular RNA candidates, distinct from DucS, for all the examined species. Experiments testing for the presence of selected circular RNA candidates in four species successfully validated 7 out of 9 candidates from B. altitudinis and 4 out of 5 candidates from Bacillus paralicheniformis; However, none of the candidates tested for Bacillus subtilis and Escherichia coli were detected. Our work identifies a dual-conformation regulatory RNA in B. altitutidinis, and indicates that circular RNAs exist in diverse bacteria. However, circularization of specific RNAs does not seem to be conserved across species, and the circularization mechanisms and biological functionality of the circular forms remain unclear.
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Affiliation(s)
- Ting-Ting He
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan, China
- Department of Thoracic Surgery, West China Hospital, Sichuan University, Chengdu, China
| | - Yun-Fan Xu
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan, China
| | - Xiang Li
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan, China
| | - Xia Wang
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan, China
| | - Jie-Yu Li
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan, China
| | - Dan Ou-Yang
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan, China
| | - Han-Sen Cheng
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan, China
| | - Hao-Yang Li
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan, China
| | - Jia Qin
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan, China
| | - Yu Huang
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan, China
| | - Hai-Yan Wang
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan, China.
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2
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Liu J, Zhang C, Jiang M, Ni Y, Xu Y, Wu W, Huang L, Newmaster SG, Kole C, Wu B, Liu C. Identification of circular RNAs of Cannabis sativa L. potentially involved in the biosynthesis of cannabinoids. PLANTA 2023; 257:72. [PMID: 36862222 DOI: 10.1007/s00425-023-04104-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Accepted: 02/21/2023] [Indexed: 06/18/2023]
Abstract
We identified circRNAs in the Cannabis sativa L. genome and examined their association with 28 cannabinoids in three tissues of C. sativa. Nine circRNAs are potentially involved in the biosynthesis of six cannabinoids. Cannabis sativa L. has been widely used in the production of medicine, textiles, and food for over 2500 years. The main bioactive compounds in C. sativa are cannabinoids, which have multiple important pharmacological actions. Circular RNAs (circRNAs) play essential roles in growth and development, stress resistance, and the biosynthesis of secondary metabolites. However, the circRNAs in C. sativa remain unknown. In this study, to explore the role of circRNAs in cannabinoid biosynthesis, we performed RNA-Seq and metabolomics analysis on the leaves, roots, and stems of C. sativa. We identified 741 overlapping circRNAs by three tools, of which 717, 16, and 8 circRNAs were derived from exonic, intronic, and intergenic, respectively. Functional enrichment analysis indicated that the parental genes (PGs) of circRNAs were enriched in many processes related to biological stress responses. We found that most of the circRNAs showed tissue-specific expression and 65 circRNAs were significantly correlated with their PGs (P < 0.05, |r|≥ 0.5). We also determined 28 cannabinoids by High-performance liquid chromatography-ESI-triple quadrupole-linear ion trap mass spectrometry. Ten circRNAs, including ciR0159, ciR0212, ciR0153, ciR0149, ciR0016, ciR0044, ciR0022, ciR0381, ciR0006, and ciR0025 were found to be associated with six cannabinoids by weighted gene co-expression network analysis. Twenty-nine of 53 candidate circRNAs, including 9 cannabinoids related were validated successfully using PCR amplification and Sanger sequencing. Taken together, all these results would help to enhance our acknowledge of the regulation of circRNAs, and lay the foundation for breeding new C. sativa cultivars with high cannabinoids through manipulating circRNAs.
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Affiliation(s)
- Jingting Liu
- Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100193, People's Republic of China
| | - Chang Zhang
- Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100193, People's Republic of China
| | - Mei Jiang
- Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100193, People's Republic of China
| | - Yang Ni
- Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100193, People's Republic of China
| | - Yicen Xu
- Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100193, People's Republic of China
| | - Wuwei Wu
- Guangxi Botanical Garden of Medicinal Plants, Nanning, 530023, People's Republic of China
| | - Linfang Huang
- Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100193, People's Republic of China
| | - Steven G Newmaster
- Natural Health Product Research Alliance, College of Biological Sciences, University of Guelph, Guelph, ON, N1G2W1, Canada
| | - Chittaranjan Kole
- International Climate Resilient Crop Genomics Consortium and International Phytomedomics and Nutriomics Consortium, Kolkata, 700094, India
| | - Bin Wu
- Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100193, People's Republic of China.
| | - Chang Liu
- Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100193, People's Republic of China.
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3
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Abstract
Covalently closed, single-stranded circular RNAs can be produced from viral RNA genomes as well as from the processing of cellular housekeeping noncoding RNAs and precursor messenger RNAs. Recent transcriptomic studies have surprisingly uncovered that many protein-coding genes can be subjected to backsplicing, leading to widespread expression of a specific type of circular RNAs (circRNAs) in eukaryotic cells. Here, we discuss experimental strategies used to discover and characterize diverse circRNAs at both the genome and individual gene scales. We further highlight the current understanding of how circRNAs are generated and how the mature transcripts function. Some circRNAs act as noncoding RNAs to impact gene regulation by serving as decoys or competitors for microRNAs and proteins. Others form extensive networks of ribonucleoprotein complexes or encode functional peptides that are translated in response to certain cellular stresses. Overall, circRNAs have emerged as an important class of RNAmolecules in gene expression regulation that impact many physiological processes, including early development, immune responses, neurogenesis, and tumorigenesis.
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Affiliation(s)
- Li Yang
- Center for Molecular Medicine, Children's Hospital, Fudan University and Shanghai Key Laboratory of Medical Epigenetics, International Laboratory of Medical Epigenetics and Metabolism, Ministry of Science and Technology, Institutes of Biomedical Sciences, Fudan University, Shanghai, China;
| | - Jeremy E Wilusz
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Therapeutic Innovation Center, Baylor College of Medicine, Houston, Texas, USA;
| | - Ling-Ling Chen
- State Key Laboratory of Molecular Biology, Shanghai Key Laboratory of Molecular Andrology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, China;
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
- School of Life Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou, China
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4
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Liu Y, Takagi Y, Sugijanto M, Nguyen KDM, Hirata A, Hori H, Ho CK. Genetic and Functional Analyses of Archaeal ATP-Dependent RNA Ligase in C/D Box sRNA Circularization and Ribosomal RNA Processing. Front Mol Biosci 2022; 9:811548. [PMID: 35445080 PMCID: PMC9014305 DOI: 10.3389/fmolb.2022.811548] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Accepted: 02/08/2022] [Indexed: 11/24/2022] Open
Abstract
RNA ligases play important roles in repairing and circularizing RNAs post-transcriptionally. In this study, we generated an allelic knockout of ATP-dependent RNA ligase (Rnl) in the hyperthermophilic archaeon Thermococcus kodakarensis to identify its biological targets. A comparative analysis of circular RNA reveals that the Rnl-knockout strain represses circularization of C/D box sRNAs without affecting the circularization of tRNA and rRNA processing intermediates. Recombinant archaeal Rnl could circularize C/D box sRNAs with a mutation in the conserved C/D box sequence element but not when the terminal stem structures were disrupted, suggesting that proximity of the two ends could be critical for intramolecular ligation. Furthermore, T. kodakarensis accumulates aberrant RNA fragments derived from ribosomal RNA in the absence of Rnl. These results suggest that Rnl is responsible for C/D box sRNA circularization and may also play a role in ribosomal RNA processing.
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Affiliation(s)
- Yancheng Liu
- Human Biology Program, University of Tsukuba, Tsukuba, Japan
| | - Yuko Takagi
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology, Tsukuba, Japan
| | - Milyadi Sugijanto
- Doctoral Program in Medical Sciences, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
| | | | - Akira Hirata
- Department of Natural Science, Graduate School of Technology, Industrial and Social Science, Tokushima University, Tokushima, Japan
| | - Hiroyuki Hori
- Department of Materials Science and Biotechnology, Graduate School of Science and Engineering, Ehime University, Matsuyama, Japan
| | - C. Kiong Ho
- Human Biology Program, University of Tsukuba, Tsukuba, Japan
- Doctoral Program in Medical Sciences, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
- *Correspondence: C. Kiong Ho,
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5
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Deogharia M, Gurha P. The "guiding" principles of noncoding RNA function. WILEY INTERDISCIPLINARY REVIEWS. RNA 2021; 13:e1704. [PMID: 34856642 DOI: 10.1002/wrna.1704] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 09/09/2021] [Accepted: 11/11/2021] [Indexed: 12/25/2022]
Abstract
The human genome is pervasively transcribed and yet only a small fraction of these RNAs (less than 2%) are known to code for proteins. The vast majority of the RNAs are classified as noncoding RNAs (ncRNAs) and are further subgrouped as small (shorter than 200 bases) and long noncoding RNAs. The ncRNAs have been identified in all three domains of life and regulate diverse cellular processes through transcriptional and posttranscriptional gene regulation. Most of these RNAs work in conjunction with proteins forming a wide array of base pairing interactions. The determinants of these base pairing interactions are now becoming more evident and show striking similarities among the diverse group of ncRNAs. Here we present a mechanistic overview of pairing between RNA-RNA or RNA-DNA that dictates the function of ncRNAs; we provide examples to illustrate that ncRNAs work through shared evolutionary mechanisms that encompasses a guide-target interaction, involving not only classical Watson-Crick but also noncanonical Wobble and Hoogsteen base pairing. We also highlight the similarities in target selection, proofreading, and the ruler mechanism of ncRNA-protein complexes that confers target specificity and target site selection. This article is categorized under: Regulatory RNAs/RNAi/Riboswitches > Regulatory RNAs RNA-Based Catalysis > RNA-Mediated Cleavage RNA Evolution and Genomics > RNA and Ribonucleoprotein Evolution.
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Affiliation(s)
- Manisha Deogharia
- Center for Cardiovascular Genetics, Institute of Molecular Medicine, Houston, Texas, USA.,University of Texas Health Sciences Center at Houston, Houston, Texas, USA
| | - Priyatansh Gurha
- Center for Cardiovascular Genetics, Institute of Molecular Medicine, Houston, Texas, USA.,University of Texas Health Sciences Center at Houston, Houston, Texas, USA
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6
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Talross GJS, Deryusheva S, Gall JG. Stable lariats bearing a snoRNA (slb-snoRNA) in eukaryotic cells: A level of regulation for guide RNAs. Proc Natl Acad Sci U S A 2021; 118:e2114156118. [PMID: 34725166 PMCID: PMC8609340 DOI: 10.1073/pnas.2114156118] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/26/2021] [Indexed: 12/31/2022] Open
Abstract
Small nucleolar (sno)RNAs guide posttranscriptional modifications essential for the biogenesis and function of their target. The majority of snoRNAs in higher eukaryotes are encoded within introns. They are first released from nascent transcripts in the form of a lariat and rapidly targeted by the debranching enzyme and nuclear exonucleases for linearization and further trimming. In this study, we report that some snoRNAs are encoded within unusually stable intronic RNAs. These intronic sequences can escape the debranching enzyme and accumulate as lariats. Stable lariats bearing a snoRNA, or slb-snoRNA, are associated with snoRNA binding proteins but do not guide posttranscriptional modification. While most slb-snoRNAs accumulate in the nucleus, some can be exported to the cytoplasm. We find that this export competes with snoRNA maturation. Slb-snoRNAs provide a previously unknown layer of regulation to snoRNA and snoRNA binding proteins.
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Affiliation(s)
- Gaëlle J S Talross
- Department of Embryology, Carnegie Institution for Science, Baltimore, MD 21218
| | - Svetlana Deryusheva
- Department of Embryology, Carnegie Institution for Science, Baltimore, MD 21218
| | - Joseph G Gall
- Department of Embryology, Carnegie Institution for Science, Baltimore, MD 21218
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7
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Breuer R, Gomes-Filho JV, Randau L. Conservation of Archaeal C/D Box sRNA-Guided RNA Modifications. Front Microbiol 2021; 12:654029. [PMID: 33776983 PMCID: PMC7994747 DOI: 10.3389/fmicb.2021.654029] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 02/19/2021] [Indexed: 12/18/2022] Open
Abstract
Post-transcriptional modifications fulfill many important roles during ribosomal RNA maturation in all three domains of life. Ribose 2'-O-methylations constitute the most abundant chemical rRNA modification and are, for example, involved in RNA folding and stabilization. In archaea, these modification sites are determined by variable sets of C/D box sRNAs that guide the activity of the rRNA 2'-O-methyltransferase fibrillarin. Each C/D box sRNA contains two guide sequences that can act in coordination to bridge rRNA sequences. Here, we will review the landscape of archaeal C/D box sRNA genes and their target sites. One focus is placed on the apparent accelerated evolution of guide sequences and the varied pairing of the two individual guides, which results in different rRNA modification patterns and RNA chaperone activities.
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Affiliation(s)
| | | | - Lennart Randau
- Prokaryotic RNA Biology, Philipps-Universität Marburg, Marburg, Germany
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8
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Birkedal U, Beckert B, Wilson DN, Nielsen H. The 23S Ribosomal RNA From Pyrococcus furiosus Is Circularly Permuted. Front Microbiol 2020; 11:582022. [PMID: 33362734 PMCID: PMC7758197 DOI: 10.3389/fmicb.2020.582022] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Accepted: 11/16/2020] [Indexed: 12/29/2022] Open
Abstract
Synthesis and assembly of ribosomal components are fundamental cellular processes and generally well-conserved within the main groups of organisms. Yet, provocative variations to the general schemes exist. We have discovered an unusual processing pathway of pre-rRNA in extreme thermophilic archaea exemplified by Pyrococcus furiosus. The large subunit (LSU) rRNA is produced as a circularly permuted form through circularization followed by excision of Helix 98. As a consequence, the terminal domain VII that comprise the binding site for the signal recognition particle is appended to the 5´ end of the LSU rRNA that instead terminates in Domain VI carrying the Sarcin-Ricin Loop, the primary interaction site with the translational GTPases. To our knowledge, this is the first example of a true post-transcriptional circular permutation of a main functional molecule and the first example of rRNA fragmentation in archaea.
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Affiliation(s)
- Ulf Birkedal
- Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Bertrand Beckert
- Institut für Biochemie und Molekularbiologie, Universität Hamburg, Hamburg, Germany
| | - Daniel N Wilson
- Institut für Biochemie und Molekularbiologie, Universität Hamburg, Hamburg, Germany
| | - Henrik Nielsen
- Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark.,Genomics Group, Nord University, Bodø, Norway
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9
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Li X, Zhang B, Li F, Yu K, Bai Y. The mechanism and detection of alternative splicing events in circular RNAs. PeerJ 2020; 8:e10032. [PMID: 33033662 PMCID: PMC7521338 DOI: 10.7717/peerj.10032] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 09/03/2020] [Indexed: 01/15/2023] Open
Abstract
Circular RNAs (circRNAs) are considered as functional biomolecules with tissue/development-specific expression patterns. Generally, a single gene may generate multiple circRNA variants by alternative splicing, which contain different combinations of exons and/or introns. Due to the low abundance of circRNAs as well as overlapped with their linear counterparts, circRNA enrichment protocol is needed prior to sequencing. Compared with numerous algorithms, which use back-splicing reads for detection and functional characterization of circRNAs, original bioinformatic analyzing tools have been developed to large-scale determination of full-length circRNAs and accurate quantification. This review provides insights into the complexity of circRNA biogenesis and surveys the recent progresses in the experimental and bioinformatic methodologies that focus on accurately full-length circRNAs identification.
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Affiliation(s)
- Xiaohan Li
- State Key Laboratory of Bioelectronics, School of Biological Sciences and Medical Engineering, Southeast University, Nanjing, Jiangsu, China
| | - Bing Zhang
- State Key Laboratory of Bioelectronics, School of Biological Sciences and Medical Engineering, Southeast University, Nanjing, Jiangsu, China
| | - Fuyu Li
- State Key Laboratory of Bioelectronics, School of Biological Sciences and Medical Engineering, Southeast University, Nanjing, Jiangsu, China
| | - Kequan Yu
- State Key Laboratory of Bioelectronics, School of Biological Sciences and Medical Engineering, Southeast University, Nanjing, Jiangsu, China
| | - Yunfei Bai
- State Key Laboratory of Bioelectronics, School of Biological Sciences and Medical Engineering, Southeast University, Nanjing, Jiangsu, China
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10
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Schmidt CA, Matera AG. tRNA introns: Presence, processing, and purpose. WILEY INTERDISCIPLINARY REVIEWS-RNA 2019; 11:e1583. [DOI: 10.1002/wrna.1583] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 12/05/2019] [Accepted: 12/07/2019] [Indexed: 12/18/2022]
Affiliation(s)
- Casey A. Schmidt
- Curriculum in Genetics and Molecular Biology Integrative Program for Biological and Genome Sciences, University of North Carolina Chapel Hill North Carolina
| | - A. Gregory Matera
- Curriculum in Genetics and Molecular Biology Integrative Program for Biological and Genome Sciences, University of North Carolina Chapel Hill North Carolina
- Department of Biology, Lineberger Comprehensive Cancer Center University of North Carolina Chapel Hill North Carolina
- Department of Genetics, Lineberger Comprehensive Cancer Center University of North Carolina Chapel Hill North Carolina
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11
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Zhang X, Ma X, Ning L, Li Z, Zhao K, Li K, He J, Yin D. Genome-wide identification of circular RNAs in peanut (Arachis hypogaea L.). BMC Genomics 2019; 20:653. [PMID: 31416415 PMCID: PMC6694679 DOI: 10.1186/s12864-019-6020-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Accepted: 08/09/2019] [Indexed: 01/16/2023] Open
Abstract
Background Circular RNAs (circRNAs), a class of widely expressed endogenous regulatory RNAs, are involved in diverse physiological and developmental processes in eukaryotic cells. However, there have been no related studies on the number of circRNAs and their overall characteristics including circRNA abundance and expression profiles in peanut, which is one of the most important edible oil seed crops in the world. Results We performed a genome-wide identification of circular RNAs using ribosomal-depleted RNA-sequencing from the seeds of two peanut eighth-generation recombinant inbred lines (RIL8): ‘RIL 8106’ (a medium-pod variety) and ‘RIL 8107’ (a super-pod variety), at 15 and 35 days after flowering (DAF), respectively. A total of 347 circRNA candidates were detected by two computational pipelines: CIRCexplorer and CIRI, with at least two supporting junction reads. All these circRNAs were generated from exons of annotated genes, and widespread on the 20 peanut chromosomes. The expression profiles revealed that circRNAs were differentially expressed between two stages and between two lines. GO enrichment analysis of the host genes produced differentially-expressed circRNAs suggested that circRNAs are involved in seed development and regulation of seed size. Fifteen circRNAs were experimentally analyzed by qRT-PCR with divergent primers, and six circRNAs were resistant to digestion with RNase R exonuclease, and the back-splicing sites were further validated by Sanger DNA sequencing. Conclusions We present the first systematical investigation of the genomic characteristics and expression profiles of circRNAs in peanut. The results revealed that circRNAs are abundant and widespread in peanut, and the differentially-expressed circRNAs between two lines suggested that they might play regulatory roles in peanut seeds development. Electronic supplementary material The online version of this article (10.1186/s12864-019-6020-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Xingguo Zhang
- College of Agronomy, Henan Agricultural University, 95 Wenhua Road, Zhengzhou, Henan, 450002, People's Republic of China
| | - Xingli Ma
- College of Agronomy, Henan Agricultural University, 95 Wenhua Road, Zhengzhou, Henan, 450002, People's Republic of China
| | - Longlong Ning
- College of Agronomy, Henan Agricultural University, 95 Wenhua Road, Zhengzhou, Henan, 450002, People's Republic of China
| | - Zhongfeng Li
- College of Agronomy, Henan Agricultural University, 95 Wenhua Road, Zhengzhou, Henan, 450002, People's Republic of China
| | - Kunkun Zhao
- College of Agronomy, Henan Agricultural University, 95 Wenhua Road, Zhengzhou, Henan, 450002, People's Republic of China
| | - Ke Li
- College of Agronomy, Henan Agricultural University, 95 Wenhua Road, Zhengzhou, Henan, 450002, People's Republic of China
| | - Jialin He
- College of Agronomy, Henan Agricultural University, 95 Wenhua Road, Zhengzhou, Henan, 450002, People's Republic of China
| | - Dongmei Yin
- College of Agronomy, Henan Agricultural University, 95 Wenhua Road, Zhengzhou, Henan, 450002, People's Republic of China.
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12
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Lui LM, Uzilov AV, Bernick DL, Corredor A, Lowe TM, Dennis PP. Methylation guide RNA evolution in archaea: structure, function and genomic organization of 110 C/D box sRNA families across six Pyrobaculum species. Nucleic Acids Res 2019; 46:5678-5691. [PMID: 29771354 PMCID: PMC6009581 DOI: 10.1093/nar/gky284] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Accepted: 04/23/2018] [Indexed: 12/21/2022] Open
Abstract
Archaeal homologs of eukaryotic C/D box small nucleolar RNAs (C/D box sRNAs) guide precise 2′-O-methyl modification of ribosomal and transfer RNAs. Although C/D box sRNA genes constitute one of the largest RNA gene families in archaeal thermophiles, most genomes have incomplete sRNA gene annotation because reliable, fully automated detection methods are not available. We expanded and curated a comprehensive gene set across six species of the crenarchaeal genus Pyrobaculum, particularly rich in C/D box sRNA genes. Using high-throughput small RNA sequencing, specialized computational searches and comparative genomics, we analyzed 526 Pyrobaculum C/D box sRNAs, organizing them into 110 families based on synteny and conservation of guide sequences which determine methylation targets. We examined gene duplications and rearrangements, including one family that has expanded in a pattern similar to retrotransposed repetitive elements in eukaryotes. New training data and inclusion of kink-turn secondary structural features enabled creation of an improved search model. Our analyses provide the most comprehensive, dynamic view of C/D box sRNA evolutionary history within a genus, in terms of modification function, feature plasticity, and gene mobility.
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Affiliation(s)
- Lauren M Lui
- Department of Biomolecular Engineering, University of California Santa Cruz, Santa Cruz, CA 95064, USA
| | - Andrew V Uzilov
- Department of Biomolecular Engineering, University of California Santa Cruz, Santa Cruz, CA 95064, USA
| | - David L Bernick
- Department of Biomolecular Engineering, University of California Santa Cruz, Santa Cruz, CA 95064, USA
| | - Andrea Corredor
- Department of Biomolecular Engineering, University of California Santa Cruz, Santa Cruz, CA 95064, USA
| | - Todd M Lowe
- Department of Biomolecular Engineering, University of California Santa Cruz, Santa Cruz, CA 95064, USA
| | - Patrick P Dennis
- Department of Biology, Whitman College, Walla Walla, WA 99362, USA
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13
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Becker HF, L'Hermitte-Stead C, Myllykallio H. Diversity of circular RNAs and RNA ligases in archaeal cells. Biochimie 2019; 164:37-44. [PMID: 31212038 DOI: 10.1016/j.biochi.2019.06.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Accepted: 06/13/2019] [Indexed: 01/16/2023]
Abstract
Circular RNAs (circRNAs) differ structurally from other types of RNAs and are resistant against exoribonucleases. Although they have been detected in all domains of life, it remains unclear how circularization affects or changes functions of these ubiquitous nucleic acid circles. The biogenesis of circRNAs has been mostly described as a backsplicing event, but in archaea, where RNA splicing is a rare phenomenon, a second pathway for circRNA formation was described in the cases of rRNAs processing, tRNA intron excision, and Box C/D RNAs formation. At least in some archaeal species, circRNAs are formed by a ligation step catalyzed by an atypic homodimeric RNA ligase belonging to Rnl3 family. In this review, we describe archaeal circRNA transcriptomes obtained using high throughput sequencing technologies on Sulfolobus solfataricus, Pyrococcus abyssi and Nanoarchaeum equitans cells. We will discuss the distribution of circular RNAs among the different RNA categories and present the Rnl3 ligase family implicated in the circularization activity. Special focus is given for the description of phylogenetic distributions, protein structures, and substrate specificities of archaeal RNA ligases.
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Affiliation(s)
- Hubert F Becker
- LOB, Ecole Polytechnique, CNRS, INSERM, Institut Polytechnique de Paris, 91128, Palaiseau, France; Sorbonne Université, Faculté des Sciences et Ingénierie, 75005, Paris, France.
| | | | - Hannu Myllykallio
- LOB, Ecole Polytechnique, CNRS, INSERM, Institut Polytechnique de Paris, 91128, Palaiseau, France
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14
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Clouet-d'Orval B, Batista M, Bouvier M, Quentin Y, Fichant G, Marchfelder A, Maier LK. Insights into RNA-processing pathways and associated RNA-degrading enzymes in Archaea. FEMS Microbiol Rev 2018; 42:579-613. [PMID: 29684129 DOI: 10.1093/femsre/fuy016] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Accepted: 04/17/2018] [Indexed: 12/20/2022] Open
Abstract
RNA-processing pathways are at the centre of regulation of gene expression. All RNA transcripts undergo multiple maturation steps in addition to covalent chemical modifications to become functional in the cell. This includes destroying unnecessary or defective cellular RNAs. In Archaea, information on mechanisms by which RNA species reach their mature forms and associated RNA-modifying enzymes are still fragmentary. To date, most archaeal actors and pathways have been proposed in light of information gathered from Bacteria and Eukarya. In this context, this review provides a state of the art overview of archaeal endoribonucleases and exoribonucleases that cleave and trim RNA species and also of the key small archaeal proteins that bind RNAs. Furthermore, synthetic up-to-date views of processing and biogenesis pathways of archaeal transfer and ribosomal RNAs as well as of maturation of stable small non-coding RNAs such as CRISPR RNAs, small C/D and H/ACA box guide RNAs, and other emerging classes of small RNAs are described. Finally, prospective post-transcriptional mechanisms to control archaeal messenger RNA quality and quantity are discussed.
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Affiliation(s)
- Béatrice Clouet-d'Orval
- Laboratoire de Microbiologie et de Génétique Moléculaires (LMGM), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, 31062 Toulouse, France
| | - Manon Batista
- Laboratoire de Microbiologie et de Génétique Moléculaires (LMGM), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, 31062 Toulouse, France
| | - Marie Bouvier
- Laboratoire de Microbiologie et de Génétique Moléculaires (LMGM), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, 31062 Toulouse, France
| | - Yves Quentin
- Laboratoire de Microbiologie et de Génétique Moléculaires (LMGM), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, 31062 Toulouse, France
| | - Gwennaele Fichant
- Laboratoire de Microbiologie et de Génétique Moléculaires (LMGM), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, 31062 Toulouse, France
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15
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Noncoding RNAs in Archaea: Genome-Wide Identification and Functional Classification. Methods Enzymol 2018; 612:413-442. [DOI: 10.1016/bs.mie.2018.08.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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16
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Dou Y, Li S, Yang W, Liu K, Du Q, Ren G, Yu B, Zhang C. Genome-wide Discovery of Circular RNAs in the Leaf and Seedling Tissues of Arabidopsis Thaliana. Curr Genomics 2017; 18:360-365. [PMID: 29081691 PMCID: PMC5635619 DOI: 10.2174/1389202918666170307161124] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Revised: 10/12/2016] [Accepted: 10/27/2016] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Recently, identification and functional studies of circular RNAs, a type of non-coding RNAs arising from a ligation of 3' and 5' ends of a linear RNA molecule, were conducted in mammalian cells with the development of RNA-seq technology. METHOD Since compared with animals, studies on circular RNAs in plants are less thorough, a genome-wide identification of circular RNA candidates in Arabidopsis was conducted with our own developed bioinformatics tool to several existing RNA-seq datasets specifically for non-coding RNAs. RESULTS A total of 164 circular RNA candidates were identified from RNA-seq data, and 4 circular RNA transcripts, including both exonic and intronic circular RNAs, were experimentally validated. Interestingly, our results show that circular RNA transcripts are enriched in the photosynthesis system for the leaf tissue and correlated to the higher expression levels of their parent genes. Sixteen out of all 40 genes that have circular RNA candidates are related to the photosynthesis system, and out of the total 146 exonic circular RNA candidates, 63 are found in chloroplast.
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Affiliation(s)
- Yongchao Dou
- School of Biological Sciences, University of Nebraska, Lincoln, Nebraska, USA
| | - Shengjun Li
- School of Biological Sciences, University of Nebraska, Lincoln, Nebraska, USA
| | - Weilong Yang
- School of Biological Sciences, University of Nebraska, Lincoln, Nebraska, USA
| | - Kan Liu
- School of Biological Sciences, University of Nebraska, Lincoln, Nebraska, USA
| | - Qian Du
- School of Biological Sciences, University of Nebraska, Lincoln, Nebraska, USA
| | - Guodong Ren
- State Key Laboratory of Genetic Engineering, Institute of Plant Biology and Department of Biochemistry, School of Life Sciences, Fudan University, Shanghai, China
| | - Bin Yu
- School of Biological Sciences, University of Nebraska, Lincoln, Nebraska, USA
| | - Chi Zhang
- School of Biological Sciences, University of Nebraska, Lincoln, Nebraska, USA
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17
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Becker HF, Héliou A, Djaout K, Lestini R, Regnier M, Myllykallio H. High-throughput sequencing reveals circular substrates for an archaeal RNA ligase. RNA Biol 2017; 14:1075-1085. [PMID: 28277897 DOI: 10.1080/15476286.2017.1302640] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
It is only recently that the abundant presence of circular RNAs (circRNAs) in all kingdoms of Life, including the hyperthermophilic archaeon Pyrococcus abyssi, has emerged. This led us to investigate the physiologic significance of a previously observed weak intramolecular ligation activity of Pab1020 RNA ligase. Here we demonstrate that this enzyme, despite sharing significant sequence similarity with DNA ligases, is indeed an RNA-specific polynucleotide ligase efficiently acting on physiologically significant substrates. Using a combination of RNA immunoprecipitation assays and RNA-seq, our genome-wide studies revealed 133 individual circRNA loci in P. abyssi. The large majority of these loci interacted with Pab1020 in cells and circularization of selected C/D Box and 5S rRNA transcripts was confirmed biochemically. Altogether these studies revealed that Pab1020 is required for RNA circularization. Our results further suggest the functional speciation of an ancestral NTase domain and/or DNA ligase toward RNA ligase activity and prompt for further characterization of the widespread functions of circular RNAs in prokaryotes. Detailed insight into the cellular substrates of Pab1020 may facilitate the development of new biotechnological applications e.g. in ligation of preadenylated adaptors to RNA molecules.
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Affiliation(s)
- Hubert F Becker
- a LOB, Ecole Polytechnique, CNRS, INSERM, Université Paris-Saclay , Palaiseau , France.,b Sorbonne Universités, UPMC Univ Paris 06 , 4 Place Jussieu, Paris , France
| | - Alice Héliou
- a LOB, Ecole Polytechnique, CNRS, INSERM, Université Paris-Saclay , Palaiseau , France.,c LIX, Ecole Polytechnique, CNRS, Université Paris-Saclay, INRIA , Palaiseau , France
| | - Kamel Djaout
- a LOB, Ecole Polytechnique, CNRS, INSERM, Université Paris-Saclay , Palaiseau , France
| | - Roxane Lestini
- a LOB, Ecole Polytechnique, CNRS, INSERM, Université Paris-Saclay , Palaiseau , France
| | - Mireille Regnier
- c LIX, Ecole Polytechnique, CNRS, Université Paris-Saclay, INRIA , Palaiseau , France
| | - Hannu Myllykallio
- a LOB, Ecole Polytechnique, CNRS, INSERM, Université Paris-Saclay , Palaiseau , France
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18
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Tripp V, Martin R, Orell A, Alkhnbashi OS, Backofen R, Randau L. Plasticity of archaeal C/D box sRNA biogenesis. Mol Microbiol 2016; 103:151-164. [PMID: 27743417 DOI: 10.1111/mmi.13549] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/04/2016] [Indexed: 01/11/2023]
Abstract
Archaeal and eukaryotic organisms contain sets of C/D box s(no)RNAs with guide sequences that determine ribose 2'-O-methylation sites of target RNAs. The composition of these C/D box sRNA sets is highly variable between organisms and results in varying RNA modification patterns which are important for ribosomal RNA folding and stability. Little is known about the genomic organization of C/D box sRNA genes in archaea. Here, we aimed to obtain first insights into the biogenesis of these archaeal C/D box sRNAs and analyzed the genetic context of more than 300 archaeal sRNA genes. We found that the majority of these genes do not possess independent promoters but are rather located at positions that allow for co-transcription with neighboring genes and their start or stop codons were frequently incorporated into the conserved boxC and D motifs. The biogenesis of plasmid-encoded C/D box sRNA variants was analyzed in vivo in Sulfolobus acidocaldarius. It was found that C/D box sRNA maturation occurs independent of their genetic context and relies solely on the presence of intact RNA kink-turn structures. The observed plasticity of C/D box sRNA biogenesis is suggested to enable their accelerated evolution and, consequently, allow for adjustments of the RNA modification landscape.
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Affiliation(s)
- Vanessa Tripp
- Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch Strasse 10, Marburg, 35043, Germany.,LOEWE Center for Synthetic Microbiology, SYNMIKRO, Karl-von-Frisch-Strasse 16, Marburg, 35043, Germany
| | - Roman Martin
- Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch Strasse 10, Marburg, 35043, Germany
| | - Alvaro Orell
- Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch Strasse 10, Marburg, 35043, Germany
| | - Omer S Alkhnbashi
- Bioinformatics group, Department of Computer Science, University of Freiburg, Georges-Köhler-Allee 106, Freiburg, 79110, Germany
| | - Rolf Backofen
- Bioinformatics group, Department of Computer Science, University of Freiburg, Georges-Köhler-Allee 106, Freiburg, 79110, Germany.,BIOSS Centre for Biological Signalling Studies, Cluster of Excellence, University of Freiburg, Germany
| | - Lennart Randau
- Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch Strasse 10, Marburg, 35043, Germany.,LOEWE Center for Synthetic Microbiology, SYNMIKRO, Karl-von-Frisch-Strasse 16, Marburg, 35043, Germany
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Abstract
Profiling the RNA production in hyperthermophilic archaea revealed an abundance of small RNA-guided processes near the upper temperature limit of life. Archaea utilize the base-pairing ability of RNA guide sequences to target ribosomal RNAs, transfer RNAs, messenger RNAs, and viral genomes. Cellular processes that are guided by small RNAs include the modification of RNA molecules, trans-splicing, gene regulation, and RNA and DNA degradation. Here, a brief overview of our knowledge on small guide RNA genes in archaeal genomes is provided and examples of their putative roles in genome evolution are described.
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MESH Headings
- Archaea/genetics
- Base Sequence
- Evolution, Molecular
- Gene Expression Regulation, Archaeal
- Genome, Archaeal/genetics
- Hot Temperature
- Models, Genetic
- RNA, Archaeal/genetics
- RNA, Archaeal/metabolism
- RNA, Guide, CRISPR-Cas Systems/genetics
- RNA, Guide, CRISPR-Cas Systems/metabolism
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Affiliation(s)
- Lennart Randau
- Prokaryotic Small RNA Biology, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
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20
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Abstract
It is now clear that there is a diversity of circular RNAs in biological systems. Circular RNAs can be produced by the direct ligation of 5' and 3' ends of linear RNAs, as intermediates in RNA processing reactions, or by "backsplicing," wherein a downstream 5' splice site (splice donor) is joined to an upstream 3' splice site (splice acceptor). Circular RNAs have unique properties including the potential for rolling circle amplification of RNA, the ability to rearrange the order of genomic information, protection from exonucleases, and constraints on RNA folding. Circular RNAs can function as templates for viroid and viral replication, as intermediates in RNA processing reactions, as regulators of transcription in cis, as snoRNAs, and as miRNA sponges. Herein, we review the breadth of circular RNAs, their biogenesis and metabolism, and their known and anticipated functions.
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Affiliation(s)
- Erika Lasda
- Department of Chemistry and Biochemistry, Howard Hughes Medical Institute, University of Colorado, Boulder, Colorado 80309, USA
| | - Roy Parker
- Department of Chemistry and Biochemistry, Howard Hughes Medical Institute, University of Colorado, Boulder, Colorado 80309, USA
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21
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Abstract
snoRNAs (small nucleolar RNAs) constitute one of the largest and best-studied classes of non-coding RNAs that confer enzymatic specificity. With associated proteins, these snoRNAs form ribonucleoprotein complexes that can direct 2'-O-methylation or pseudouridylation of target non-coding RNAs. Aided by computational methods and high-throughput sequencing, new studies have expanded the diversity of known snoRNA functions. Complexes incorporating snoRNAs have dynamic specificity, and include diverse roles in RNA silencing, telomerase maintenance and regulation of alternative splicing. Evidence that dysregulation of snoRNAs can cause human disease, including cancer, indicates that the full scope of snoRNA roles remains an unfinished story. The diversity in structure, genomic origin and function between snoRNAs found in different complexes and among different phyla illustrates the surprising plasticity of snoRNAs in evolution. The ability of snoRNAs to direct highly specific interactions with other RNAs is a consistent thread in their newly discovered functions. Because they are ubiquitous throughout Eukarya and Archaea, it is likely they were a feature of the last common ancestor of these two domains, placing their origin over two billion years ago. In the present chapter, we focus on recent advances in our understanding of these ancient, but functionally dynamic RNA-processing machines.
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22
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C/D box sRNA, CRISPR RNA and tRNA processing in an archaeon with a minimal fragmented genome. Biochem Soc Trans 2013; 41:411-5. [PMID: 23356320 DOI: 10.1042/bst20120276] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The analysis of deep sequencing data allows for a genome-wide overview of all the small RNA molecules (the 'sRNome') that are present in a single organism. In the present paper, we review the processing of CRISPR (clustered regularly interspaced short palindromic repeats) RNA, C/D box sRNA (small non-coding RNA) and tRNA in Nanoarchaeum equitans. The minimal and fragmented genome of this tiny archaeon permits a sequencing depth that enables the identification of processing intermediates in the study of RNA processing pathways. These intermediates include circular C/D box sRNA molecules and tRNA half precursors.
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23
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Su AAH, Tripp V, Randau L. RNA-Seq analyses reveal the order of tRNA processing events and the maturation of C/D box and CRISPR RNAs in the hyperthermophile Methanopyrus kandleri. Nucleic Acids Res 2013; 41:6250-8. [PMID: 23620296 PMCID: PMC3695527 DOI: 10.1093/nar/gkt317] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Revised: 04/03/2013] [Accepted: 04/05/2013] [Indexed: 11/29/2022] Open
Abstract
The methanogenic archaeon Methanopyrus kandleri grows near the upper temperature limit for life. Genome analyses revealed strategies to adapt to these harsh conditions and elucidated a unique transfer RNA (tRNA) C-to-U editing mechanism at base 8 for 30 different tRNA species. Here, RNA-Seq deep sequencing methodology was combined with computational analyses to characterize the small RNome of this hyperthermophilic organism and to obtain insights into the RNA metabolism at extreme temperatures. A large number of 132 small RNAs were identified that guide RNA modifications, which are expected to stabilize structured RNA molecules. The C/D box guide RNAs were shown to exist as circular RNA molecules. In addition, clustered regularly interspaced short palindromic repeats RNA processing and potential regulatory RNAs were identified. Finally, the identification of tRNA precursors before and after the unique C8-to-U8 editing activity enabled the determination of the order of tRNA processing events with termini truncation preceding intron removal. This order of tRNA maturation follows the compartmentalized tRNA processing order found in Eukaryotes and suggests its conservation during evolution.
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MESH Headings
- Euryarchaeota/genetics
- Euryarchaeota/metabolism
- High-Throughput Nucleotide Sequencing
- Hot Temperature
- Inverted Repeat Sequences
- RNA Editing
- RNA Processing, Post-Transcriptional
- RNA, Archaeal/chemistry
- RNA, Archaeal/classification
- RNA, Archaeal/metabolism
- RNA, Small Untranslated/chemistry
- RNA, Small Untranslated/classification
- RNA, Small Untranslated/metabolism
- RNA, Transfer/chemistry
- RNA, Transfer/metabolism
- Sequence Analysis, RNA
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Affiliation(s)
- Andreas A. H. Su
- Max-Planck-Institute for Terrestrial Microbiology, Max Planck Research Group: Prokaryotic Small RNA Biology, Karl-von-Frisch Strasse 10, 35037 Marburg, Germany and LOEWE Center for Synthetic Microbiology (Synmikro), 35037 Marburg, Germany
| | - Vanessa Tripp
- Max-Planck-Institute for Terrestrial Microbiology, Max Planck Research Group: Prokaryotic Small RNA Biology, Karl-von-Frisch Strasse 10, 35037 Marburg, Germany and LOEWE Center for Synthetic Microbiology (Synmikro), 35037 Marburg, Germany
| | - Lennart Randau
- Max-Planck-Institute for Terrestrial Microbiology, Max Planck Research Group: Prokaryotic Small RNA Biology, Karl-von-Frisch Strasse 10, 35037 Marburg, Germany and LOEWE Center for Synthetic Microbiology (Synmikro), 35037 Marburg, Germany
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24
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Doose G, Alexis M, Kirsch R, Findeiß S, Langenberger D, Machné R, Mörl M, Hoffmann S, Stadler PF. Mapping the RNA-Seq trash bin: unusual transcripts in prokaryotic transcriptome sequencing data. RNA Biol 2013; 10:1204-10. [PMID: 23702463 DOI: 10.4161/rna.24972] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Prokaryotic transcripts constitute almost always uninterrupted intervals when mapped back to the genome. Split reads, i.e., RNA-seq reads consisting of parts that only map to discontiguous loci, are thus disregarded in most analysis pipelines. There are, however, some well-known exceptions, in particular, tRNA splicing and circularized small RNAs in Archaea as well as self-splicing introns. Here, we reanalyze a series of published RNA-seq data sets, screening them specifically for non-contiguously mapping reads. We recover most of the known cases together with several novel archaeal ncRNAs associated with circularized products. In Eubacteria, only a handful of interesting candidates were obtained beyond a few previously described group I and group II introns. Most of the atypically mapping reads do not appear to correspond to well-defined, specifically processed products. Whether this diffuse background is, at least in part, an incidental by-product of prokaryotic RNA processing or whether it consists entirely of technical artifacts of reverse transcription or amplification remains unknown.
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Affiliation(s)
- Gero Doose
- Bioinformatics Group; Department of Computer Science, and Interdisciplinary Center for Bioinformatics; University of Leipzig; Leipzig, Germany; Transcriptome Bioinformatics; LIFE - Leipzig Research Center for Civilization Diseases; University of Leipzig; Leipzig, Germany
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25
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Jäger D, Pernitzsch SR, Richter AS, Backofen R, Sharma CM, Schmitz RA. An archaeal sRNA targeting cis- and trans-encoded mRNAs via two distinct domains. Nucleic Acids Res 2012; 40:10964-79. [PMID: 22965121 PMCID: PMC3510493 DOI: 10.1093/nar/gks847] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
We report on the characterization and target analysis of the small (s)RNA162 in the methanoarchaeon Methanosarcina mazei. Using a combination of genetic approaches, transcriptome analysis and computational predictions, the bicistronic MM2441-MM2440 mRNA encoding the transcription factor MM2441 and a protein of unknown function was identified as a potential target of this sRNA, which due to processing accumulates as three stabile 5′ fragments in late exponential growth. Mobility shift assays using various mutants verified that the non-structured single-stranded linker region of sRNA162 (SLR) base-pairs with the MM2440-MM2441 mRNA internally, thereby masking the predicted ribosome binding site of MM2441. This most likely leads to translational repression of the second cistron resulting in dis-coordinated operon expression. Analysis of mutant RNAs in vivo confirmed that the SLR of sRNA162 is crucial for target interactions. Furthermore, our results indicate that sRNA162-controlled MM2441 is involved in regulating the metabolic switch between the carbon sources methanol and methylamine. Moreover, biochemical studies demonstrated that the 5′ end of sRNA162 targets the 5′-untranslated region of the cis-encoded MM2442 mRNA. Overall, this first study of archaeal sRNA/mRNA-target interactions unraveled that sRNA162 acts as an antisense (as)RNA on cis- and trans-encoded mRNAs via two distinct domains, indicating that cis-encoded asRNAs can have larger target regulons than previously anticipated.
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Affiliation(s)
- Dominik Jäger
- Institut für Allgemeine Mikrobiologie, Christian-Albrechts-Universität zu Kiel, Am Botanischen Garten 1-9, 24118 Kiel, Germany
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26
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Randau L. RNA processing in the minimal organism Nanoarchaeum equitans. Genome Biol 2012; 13:R63. [PMID: 22809431 PMCID: PMC3491384 DOI: 10.1186/gb-2012-13-7-r63] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2012] [Accepted: 07/18/2012] [Indexed: 01/02/2023] Open
Abstract
BACKGROUND The minimal genome of the tiny, hyperthermophilic archaeon Nanoarchaeum equitans contains several fragmented genes and revealed unusual RNA processing pathways. These include the maturation of tRNA molecules via the trans-splicing of tRNA halves and genomic rearrangements to compensate for the absence of RNase P. RESULTS Here, the RNA processing events in the N. equitans cell are analyzed using RNA-Seq deep sequencing methodology. All tRNA half precursor and tRNA termini were determined and support the tRNA trans-splicing model. The processing of CRISPR RNAs from two CRISPR clusters was verified. Twenty-seven C/D box small RNAs (sRNAs) and a H/ACA box sRNA were identified. The C/D box sRNAs were found to flank split genes, to form dicistronic tRNA-sRNA precursors and to be encoded within the tRNAMet intron. CONCLUSIONS The presented data provide an overview of the production and usage of small RNAs in a cell that has to survive with a highly reduced genome. N. equitans lost many essential metabolic pathways but maintains highly active CRISPR/Cas and rRNA modification systems that appear to play an important role in genome fragmentation.
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27
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Danan M, Schwartz S, Edelheit S, Sorek R. Transcriptome-wide discovery of circular RNAs in Archaea. Nucleic Acids Res 2011; 40:3131-42. [PMID: 22140119 PMCID: PMC3326292 DOI: 10.1093/nar/gkr1009] [Citation(s) in RCA: 426] [Impact Index Per Article: 32.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Circular RNA forms had been described in all domains of life. Such RNAs were shown to have diverse biological functions, including roles in the life cycle of viral and viroid genomes, and in maturation of permuted tRNA genes. Despite their potentially important biological roles, discovery of circular RNAs has so far been mostly serendipitous. We have developed circRNA-seq, a combined experimental/computational approach that enriches for circular RNAs and allows profiling their prevalence in a whole-genome, unbiased manner. Application of this approach to the archaeon Sulfolobus solfataricus P2 revealed multiple circular transcripts, a subset of which was further validated independently. The identified circular RNAs included expected forms, such as excised tRNA introns and rRNA processing intermediates, but were also enriched with non-coding RNAs, including C/D box RNAs and RNase P, as well as circular RNAs of unknown function. Many of the identified circles were conserved in Sulfolobus acidocaldarius, further supporting their functional significance. Our results suggest that circular RNAs, and particularly circular non-coding RNAs, are more prevalent in archaea than previously recognized, and might have yet unidentified biological roles. Our study establishes a specific and sensitive approach for identification of circular RNAs using RNA-seq, and can readily be applied to other organisms.
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Affiliation(s)
- Miri Danan
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel
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28
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Jain R, Shuman S. Characterization of a thermostable archaeal polynucleotide kinase homologous to human Clp1. RNA (NEW YORK, N.Y.) 2009; 15:923-31. [PMID: 19299550 PMCID: PMC2673061 DOI: 10.1261/rna.1492809] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2008] [Accepted: 01/21/2009] [Indexed: 05/24/2023]
Abstract
Clp1 proteins are essential components of the eukaryal mRNA 3' cleavage-polyadenylation machinery. Human Clp1 has an additional function as an RNA-specific 5'-OH polynucleotide kinase, which is implicated in RNA end healing. Yeast Clp1 has no kinase activity, although it binds ATP. Here we report that Clp1-like proteins are extant in archaea. Purification and characterization of Pyrococcus horikoshii Clp1 (PhoClp1) reveals it to be a thermostable 5'-OH polynucleotide kinase optimally active at 55 degrees C to 85 degrees C. PhoClp1 catalyzes transfer of the gamma phosphate from ATP (K (m) 16 microM) to either 5'-OH RNA or DNA ends, although it prefers RNA in a competitive situation. Increasing the monovalent salt concentration to 250 mM suppresses the DNA kinase without affecting RNA phosphorylation, suggesting that RNA is a likely substrate for this enzyme in vivo. Indeed, we show that expression of PhoClp1 in budding yeast can complement a lethal mutation in the 5'-OH RNA kinase module of tRNA ligase. PhoClp1 is a member of the P-loop phosphotransferase superfamily. Alanine mutations at the P-loop lysine (Lys49) and a conserved aspartate (Asp73) inactivate the kinase. Our studies fortify emerging evidence for an enzymatic RNA repair capacity in archaea and provide a new reagent for polynucleotide phosphorylation at high temperatures.
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Affiliation(s)
- Ruchi Jain
- Graduate Program in Chemical Biology, Sloan-Kettering Institute, New York, New York 10065, USA
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29
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Brooks MA, Meslet-Cladiére L, Graille M, Kuhn J, Blondeau K, Myllykallio H, van Tilbeurgh H. The structure of an archaeal homodimeric ligase which has RNA circularization activity. Protein Sci 2008; 17:1336-45. [PMID: 18511537 DOI: 10.1110/ps.035493.108] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The genome of Pyrococcus abyssi contains two open reading frames encoding proteins which had been previously predicted to be DNA ligases, Pab2002 and Pab1020. We show that while the former is indeed a DNA ligase, Pab1020 had no effect on the substrate deoxyoligo-ribonucleotides tested. Instead, Pab1020 catalyzes the nucleotidylation of oligo-ribonucleotides in an ATP-dependent reaction, suggesting that it is an RNA ligase. We have solved the structure of Pab1020 in complex with the ATP analog AMPPNP by single-wavelength anomalous dispersion (SAD), elucidating a structure with high structural similarity to the catalytic domains of two RNA ligases from the bacteriophage T4. Additional carboxy-terminal domains are also present, and one of these mediates contacts with a second protomer, which is related by noncrystallographic symmetry, generating a homodimeric structure. These C-terminal domains are terminated by short domain swaps which themselves end within 5 A of the active sites of the partner molecules. Additionally, we show that the protein is indeed capable of circularizing RNA molecules in an ATP-dependent reaction. These structural and biochemical results provide an insight into the potential physiological roles of Pab1020.
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Affiliation(s)
- Mark Adrian Brooks
- IBBMC-CNRS, Université de Paris-Sud, CNRS-UMR8619, IFR115, 91405 Orsay, France
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Russell AG, Schnare MN, Gray MW. A Large Collection of Compact Box C/D snoRNAs and their Isoforms in Euglena gracilis: Structural, Functional and Evolutionary Insights. J Mol Biol 2006; 357:1548-65. [PMID: 16497322 DOI: 10.1016/j.jmb.2006.01.063] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2005] [Revised: 01/10/2006] [Accepted: 01/17/2006] [Indexed: 11/27/2022]
Abstract
In the domains Eucarya and Archaea, box C/D RNAs guide methylation at the 2'-position of selected ribose residues in ribosomal RNA (rRNA). Those eukaryotic box C/D RNAs that have been identified to date are larger and more variable in size than their archaeal counterparts. Here, we report the first extensive identification and characterization of box C/D small nucleolar (sno) RNAs from the protist Euglena gracilis. Among several unexpected findings, this organism contains a large assortment of methylation-guide RNAs that are smaller and more uniformly sized than those of other eukaryotes, and that consist of surprisingly few double-guide RNAs targeting sites of rRNA modification. Our comprehensive examination of the modification status of E.gracilis rRNA indicates that many of these box C/D snoRNAs target clustered methylation sites requiring extensive, overlapping guide RNA/rRNA pairings. An examination of the structure of the RNAs, in particular the location of the functional guide elements, suggests that the distances between adjacent box elements are an important factor in determining which of the potential guide elements is used to target a site of O(2')-methylation.
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Affiliation(s)
- Anthony G Russell
- Department of Biochemistry and Molecular Biology Dalhousie University, Halifax, Nova Scotia, Canada B3H 1X5.
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Hofacker IL, Stadler PF. Memory efficient folding algorithms for circular RNA secondary structures. Bioinformatics 2006; 22:1172-6. [PMID: 16452114 DOI: 10.1093/bioinformatics/btl023] [Citation(s) in RCA: 142] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND A small class of RNA molecules, in particular the tiny genomes of viroids, are circular. Yet most structure prediction algorithms handle only linear RNAs. The most straightforward approach is to compute circular structures from 'internal' and 'external' substructures separated by a base pair. This is incompatible, however, with the memory-saving approach of the Vienna RNA Package which builds a linear RNA structure from shorter (internal) structures only. RESULT Here we describe how circular secondary structures can be obtained without additional memory requirements as a kind of 'post-processing' of the linear structures. AVAILABILITY The circular folding algorithm is implemented in the current version of the of RNAfold program of the Vienna RNA Package, which can be downloaded from http://www.tbi.univie.ac.at/RNA/
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Affiliation(s)
- Ivo L Hofacker
- Institute for Theoretical Chemistry, University of Vienna Währingerstr. 17, A-1090 Vienna, Austria
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Nolivos S, Carpousis AJ, Clouet-d'Orval B. The K-loop, a general feature of the Pyrococcus C/D guide RNAs, is an RNA structural motif related to the K-turn. Nucleic Acids Res 2005; 33:6507-14. [PMID: 16293637 PMCID: PMC1289080 DOI: 10.1093/nar/gki962] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2005] [Revised: 10/29/2005] [Accepted: 10/29/2005] [Indexed: 12/03/2022] Open
Abstract
The C/D guide RNAs predicted from the genomic sequences of three species of Pyrococcus delineate a family of small non-coding archaeal RNAs involved in the methylation of rRNA and tRNA. The C/D guides assemble into ribonucleoprotein (RNP) that contains the methyltransferase. The protein L7Ae, a key structural component of the RNP, binds to a Kink-turn (K-turn) formed by the C/D motif. The K-turn is a structure that consists of two RNA stems separated by a short asymmetric loop with a characteristic sharp bend (kink) between the two stems. The majority of the pyrococcal C/D guides contain a short 3 nt-spacer between the C'/D' motifs. We show here that conserved terminal stem-loops formed by the C'/D' motif of the Pyrococcus C/D RNAs are also L7Ae-binding sites. These stem-loops are related to the K-turn by sequence and structure, but they consist of a single stem closed by a terminal loop. We have named this structure the K-loop. We show that conserved non-canonical base pairs in the stem of the K-loop are necessary for L7Ae binding. For the C/D guides with a 3 nt-spacer we show that the sequence and length is also important. The K-loop could improve the stability of the C/D guide RNAs in Pyrococcal species, which are extreme hyperthermophiles.
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Affiliation(s)
- Sophie Nolivos
- Laboratoire de Microbiologie et Génétique Moléculaires, Centre National de la Recherche Scientifique, UMR 5100 Université Paul Sabatier118 route de Narbonne, 31062 Toulouse cedex 9, France
| | - Agamemnon J. Carpousis
- Laboratoire de Microbiologie et Génétique Moléculaires, Centre National de la Recherche Scientifique, UMR 5100 Université Paul Sabatier118 route de Narbonne, 31062 Toulouse cedex 9, France
| | - Béatrice Clouet-d'Orval
- Laboratoire de Microbiologie et Génétique Moléculaires, Centre National de la Recherche Scientifique, UMR 5100 Université Paul Sabatier118 route de Narbonne, 31062 Toulouse cedex 9, France
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Clouet-d'Orval B, Gaspin C, Mougin A. Two different mechanisms for tRNA ribose methylation in Archaea: a short survey. Biochimie 2005; 87:889-95. [PMID: 16164996 DOI: 10.1016/j.biochi.2005.02.004] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2004] [Accepted: 02/10/2005] [Indexed: 10/25/2022]
Abstract
The biogenesis of tRNA involves multiple reactions including post-transcriptional modifications and pre-tRNA splicing. Among the three domains of life, only Archaea have two different mechanisms for tRNA ribose methylation: site-specific 2'-O-methyltransferases and C/D guided-RNA machinery. Recently, the first archaeal tRNA 2'-O-methyltransferase, aTrm56, has been characterized. This enzyme is found in all archaeal genomes sequenced so far except one and belongs to the SPOUT family (class IV) of RNA methyltransferases. Its substrate is the conserved C56 in the T-loop of archaeal tRNAs. In the crenarchaeon Pyrobaculum aerophylum, in which no homologue of this methyltransferase is found, a box C/D guide sRNP insures the ribose methylation of C56. Moreover, a new twist on tRNA processing is the finding, in most euryarchaeal tRNAtrp genes, of a box C/D guide RNA within their intron specifying methylation at two sites. Modification of tRNA is an integral part of the complex maturation process of primary tRNA transcripts. In addition to their role in modification, both modification enzymes and C/D guide RNPs may have a chaperone function insuring the precise folding of the mature, functional tRNA.
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Affiliation(s)
- Béatrice Clouet-d'Orval
- Laboratoire de Microbiologie Génétique et Moléculaire, UMR5100 Université Paul-Sabatier, 118, route de Narbonne, 31062 Toulouse, France.
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Mechanisms and functions of RNA-guided RNA modification. FINE-TUNING OF RNA FUNCTIONS BY MODIFICATION AND EDITING 2004. [DOI: 10.1007/b105585] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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