1
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Liu Y, Shu J, Zhang Z, Ding N, Liu J, Liu J, Cui Y, Wang C, Chen C. A conserved Pol II elongator SPT6L mediates Pol V transcription to regulate RNA-directed DNA methylation in Arabidopsis. Nat Commun 2024; 15:4460. [PMID: 38796517 PMCID: PMC11127964 DOI: 10.1038/s41467-024-48940-8] [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: 07/04/2023] [Accepted: 05/14/2024] [Indexed: 05/28/2024] Open
Abstract
In plants, the plant-specific RNA polymerase V (Pol V) transcripts non-coding RNAs and provides a docking platform for the association of accessory proteins in the RNA-directed DNA methylation (RdDM) pathway. Various components have been uncovered that are involved in the process of DNA methylation, but it is still not clear how the transcription of Pol V is regulated. Here, we report that the conserved RNA polymerase II (Pol II) elongator, SPT6L, binds to thousands of intergenic regions in a Pol II-independent manner. The intergenic enrichment of SPT6L, interestingly, co-occupies with the largest subunit of Pol V (NRPE1) and mutation of SPT6L leads to the reduction of DNA methylation but not Pol V enrichment. Furthermore, the association of SPT6L at Pol V loci is dependent on the Pol V associated factor, SPT5L, rather than the presence of Pol V, and the interaction between SPT6L and NRPE1 is compromised in spt5l. Finally, Pol V RIP-seq reveals that SPT6L is required to maintain the amount and length of Pol V transcripts. Our findings thus uncover the critical role of a Pol II conserved elongator in Pol V mediated DNA methylation and transcription, and shed light on the mutual regulation between Pol V and II in plants.
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Affiliation(s)
- Yujuan Liu
- State Key Laboratory of Plant Diversity and Specialty Crops, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, Guangdong, 510650, China
- Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement & Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, Guangdong, 510650, China
- University of the Chinese Academy of Sciences, Beijing, 100049, China
| | - Jie Shu
- Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement & Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, Guangdong, 510650, China
- Guangdong Academy of Agricultural Sciences, Guangzhou, Guangdong, 510640, China
| | - Zhi Zhang
- State Key Laboratory of Plant Diversity and Specialty Crops, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, Guangdong, 510650, China
- Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement & Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, Guangdong, 510650, China
- University of the Chinese Academy of Sciences, Beijing, 100049, China
| | - Ning Ding
- Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement & Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, Guangdong, 510650, China
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Jinyuan Liu
- State Key Laboratory of Plant Diversity and Specialty Crops, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, Guangdong, 510650, China
- Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement & Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, Guangdong, 510650, China
- University of the Chinese Academy of Sciences, Beijing, 100049, China
| | - Jun Liu
- Guangdong Academy of Agricultural Sciences, Guangzhou, Guangdong, 510640, China
| | - Yuhai Cui
- Agriculture and Agri-Food Canada, London Research and Development Centre, London, ON, N5V 4T3, Canada
- Department of Biology, Western University, London, ON, N6A 5B7, Canada
| | - Changhu Wang
- State Key Laboratory of Plant Diversity and Specialty Crops, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, Guangdong, 510650, China.
- Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement & Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, Guangdong, 510650, China.
- University of the Chinese Academy of Sciences, Beijing, 100049, China.
| | - Chen Chen
- State Key Laboratory of Plant Diversity and Specialty Crops, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, Guangdong, 510650, China.
- Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement & Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, Guangdong, 510650, China.
- University of the Chinese Academy of Sciences, Beijing, 100049, China.
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2
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Dew-Budd KJ, Chow HT, Kendall T, David BC, Rozelle JA, Mosher RA, Beilstein MA. Mating system is associated with seed phenotypes upon loss of RNA-directed DNA methylation in Brassicaceae. PLANT PHYSIOLOGY 2024; 194:2136-2148. [PMID: 37987565 DOI: 10.1093/plphys/kiad622] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 10/03/2023] [Accepted: 10/23/2023] [Indexed: 11/22/2023]
Abstract
In plants, de novo DNA methylation is guided by 24-nt short interfering (si)RNAs in a process called RNA-directed DNA methylation (RdDM). Primarily targeted at transposons, RdDM causes transcriptional silencing and can indirectly influence expression of neighboring genes. During reproduction, a small number of siRNA loci are dramatically upregulated in the maternally derived seed coat, suggesting that RdDM might have a special function during reproduction. However, the developmental consequence of RdDM has been difficult to dissect because disruption of RdDM does not result in overt phenotypes in Arabidopsis (Arabidopsis thaliana), where the pathway has been most thoroughly studied. In contrast, Brassica rapa mutants lacking RdDM have a severe seed production defect, which is determined by the maternal sporophytic genotype. To explore the factors that underlie the different phenotypes of these species, we produced RdDM mutations in 3 additional members of the Brassicaceae family: Camelina sativa, Capsella rubella, and Capsella grandiflora. Among these 3 species, only mutations in the obligate outcrosser, C. grandiflora, displayed a seed production defect similar to Brassica rapa mutants, suggesting that mating system is a key determinant for reproductive phenotypes in RdDM mutants.
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Affiliation(s)
- Kelly J Dew-Budd
- School of Plant Sciences, University of Arizona, Tucson, AZ 85721, USA
| | - Hiu Tung Chow
- School of Plant Sciences, University of Arizona, Tucson, AZ 85721, USA
| | - Timmy Kendall
- School of Plant Sciences, University of Arizona, Tucson, AZ 85721, USA
| | - Brandon C David
- School of Plant Sciences, University of Arizona, Tucson, AZ 85721, USA
| | - James A Rozelle
- School of Plant Sciences, University of Arizona, Tucson, AZ 85721, USA
| | - Rebecca A Mosher
- School of Plant Sciences, University of Arizona, Tucson, AZ 85721, USA
| | - Mark A Beilstein
- School of Plant Sciences, University of Arizona, Tucson, AZ 85721, USA
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3
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Miloro F, Kis A, Havelda Z, Dalmadi Á. Barley AGO4 proteins show overlapping functionality with distinct small RNA-binding properties in heterologous complementation. PLANT CELL REPORTS 2024; 43:96. [PMID: 38480545 PMCID: PMC10937801 DOI: 10.1007/s00299-024-03177-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Accepted: 02/15/2024] [Indexed: 03/17/2024]
Abstract
KEY MESSAGE Barley AGO4 proteins complement expressional changes of epigenetically regulated genes in Arabidopsis ago4-3 mutant and show a distinct affinity for the 5' terminal nucleotide of small RNAs, demonstrating functional conservation and divergence. The function of Argonaute 4 (AGO4) in Arabidopsis thaliana has been extensively characterized; however, its role in monocots, which have large genomes abundantly supplemented with transposable elements (TEs), remains elusive. The study of barley AGO4 proteins can provide insights into the conserved aspects of RNA-directed DNA methylation (RdDM) and could also have further applications in the field of epigenetics or crop improvement. Bioinformatic analysis of RNA sequencing data identified two active AGO4 genes in barley, HvAGO4a and HvAGO4b. These genes function similar to AtAGO4 in an Arabidopsis heterologous complementation system, primarily binding to 24-nucleotide long small RNAs (sRNAs) and triggering methylation at specific target loci. Like AtAGO4, HvAGO4B exhibits a preference for binding sRNAs with 5' adenine residue, while also accepting 5' guanine, uracil, and cytosine residues. In contrast, HvAGO4A selectively binds only sRNAs with a 5' adenine residue. The diverse binding capacity of barley AGO4 proteins is reflected in TE-derived sRNAs and in their varying abundance. Both barley AGO4 proteins effectively restore the levels of extrachromosomal DNA and transcript abundancy of the heat-activated ONSEN retrotransposon to those observed in wild-type Arabidopsis plants. Our study provides insight into the distinct binding specificities and involvement in TE regulation of barley AGO4 proteins in Arabidopsis by heterologous complementation.
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Affiliation(s)
- Fabio Miloro
- Hungarian University of Agriculture and Life Sciences (MATE), Institute of Genetics and Biotechnology, Gödöllő, Hungary
- Agribiotechnology and Precision Breeding for Food Security National Laboratory, Plant Biotechnology Section, Gödöllő, Hungary
| | - András Kis
- Hungarian University of Agriculture and Life Sciences (MATE), Institute of Genetics and Biotechnology, Gödöllő, Hungary
| | - Zoltán Havelda
- Hungarian University of Agriculture and Life Sciences (MATE), Institute of Genetics and Biotechnology, Gödöllő, Hungary
- Agribiotechnology and Precision Breeding for Food Security National Laboratory, Plant Biotechnology Section, Gödöllő, Hungary
| | - Ágnes Dalmadi
- Hungarian University of Agriculture and Life Sciences (MATE), Institute of Genetics and Biotechnology, Gödöllő, Hungary.
- Agribiotechnology and Precision Breeding for Food Security National Laboratory, Plant Biotechnology Section, Gödöllő, Hungary.
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4
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Xie G, Du X, Hu H, Du J. Molecular mechanisms of the RNA polymerases in plant RNA-directed DNA methylation. Trends Biochem Sci 2024; 49:247-256. [PMID: 38072749 DOI: 10.1016/j.tibs.2023.11.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2023] [Revised: 11/16/2023] [Accepted: 11/21/2023] [Indexed: 03/10/2024]
Abstract
In plants, two atypical DNA-dependent RNA polymerases, RNA polymerase IV (Pol IV) and Pol V, and an RNA-DEPENDENT RNA POLYMERASE 2 (RDR2) together produce noncoding RNAs (ncRNAs) to guide the plant-specific RNA-directed DNA methylation (RdDM). Although both Pol IV and Pol V have evolved from the canonical Pol II, they have adapted to different roles in RdDM. The mechanisms of their adaptation are key to understanding plant DNA methylation and the divergent evolution of polymerases. In this review, we summarize insights that have emerged from recent structural studies of Pol IV, Pol V, and RDR2 and discuss their structural features critical for efficient ncRNA production in RdDM.
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Affiliation(s)
- Guohui Xie
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, Institute of Plant and Food Science, Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China
| | - Xuan Du
- Department of Biochemistry and Molecular Biology, International Cancer Center, Shenzhen University Medical School, Shenzhen 518060, China
| | - Hongmiao Hu
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK
| | - Jiamu Du
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, Institute of Plant and Food Science, Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China; Institute for Biological Electron Microscopy, Southern University of Science and Technology, Shenzhen 518055, China.
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5
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Shang B, Li C, Zhang X. How intrinsically disordered proteins order plant gene silencing. Trends Genet 2024; 40:260-275. [PMID: 38296708 PMCID: PMC10932933 DOI: 10.1016/j.tig.2023.12.009] [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: 10/02/2023] [Revised: 12/25/2023] [Accepted: 12/29/2023] [Indexed: 02/02/2024]
Abstract
Intrinsically disordered proteins (IDPs) and proteins with intrinsically disordered regions (IDRs) possess low sequence complexity of amino acids and display non-globular tertiary structures. They can act as scaffolds, form regulatory hubs, or trigger biomolecular condensation to control diverse aspects of biology. Emerging evidence has recently implicated critical roles of IDPs and IDR-contained proteins in nuclear transcription and cytoplasmic post-transcriptional processes, among other molecular functions. We here summarize the concepts and organizing principles of IDPs. We then illustrate recent progress in understanding the roles of key IDPs in machineries that regulate transcriptional and post-transcriptional gene silencing (PTGS) in plants, aiming at highlighting new modes of action of IDPs in controlling biological processes.
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Affiliation(s)
- Baoshuan Shang
- National Key Laboratory of Cotton Bio-breeding and Integrated Utilization (Henan University), State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng 475004, China; Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843, USA
| | - Changhao Li
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843, USA
| | - Xiuren Zhang
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843, USA; Department of Biology, Texas A&M University, College Station, TX 77843, USA.
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6
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Felgines L, Rymen B, Martins LM, Xu G, Matteoli C, Himber C, Zhou M, Eis J, Coruh C, Böhrer M, Kuhn L, Chicher J, Pandey V, Hammann P, Wohlschlegel J, Waltz F, Law JA, Blevins T. CLSY docking to Pol IV requires a conserved domain critical for small RNA biogenesis and transposon silencing. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.26.573199. [PMID: 38234754 PMCID: PMC10793415 DOI: 10.1101/2023.12.26.573199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2024]
Abstract
Eukaryotes must balance the need for gene transcription by RNA polymerase II (Pol II) against the danger of mutations caused by transposable element (TE) proliferation. In plants, these gene expression and TE silencing activities are divided between different RNA polymerases. Specifically, RNA polymerase IV (Pol IV), which evolved from Pol II, transcribes TEs to generate small interfering RNAs (siRNAs) that guide DNA methylation and block TE transcription by Pol II. While the Pol IV complex is recruited to TEs via SNF2-like CLASSY (CLSY) proteins, how Pol IV partners with the CLSYs remains unknown. Here we identified a conserved CYC-YPMF motif that is specific to Pol IV and is positioned on the complex exterior. Furthermore, we found that this motif is essential for the co-purification of all four CLSYs with Pol IV, but that only one CLSY is present in any given Pol IV complex. These findings support a "one CLSY per Pol IV" model where the CYC-YPMF motif acts as a CLSY-docking site. Indeed, mutations in and around this motif phenocopy pol iv null mutants. Together, these findings provide structural and functional insights into a critical protein feature that distinguishes Pol IV from other RNA polymerases, allowing it to promote genome stability by targeting TEs for silencing.
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7
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Martins LM, Law JA. Moving targets: Mechanisms regulating siRNA production and DNA methylation during plant development. CURRENT OPINION IN PLANT BIOLOGY 2023; 75:102435. [PMID: 37598540 PMCID: PMC10581331 DOI: 10.1016/j.pbi.2023.102435] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Revised: 06/29/2023] [Accepted: 07/10/2023] [Indexed: 08/22/2023]
Abstract
DNA methylation is a conserved modification that must be precisely regulated during development to facilitate its roles in silencing transposable elements and regulating gene expression. In plants, DNA methylation changes during reproduction are widely documented and, in many cases, the underlying mechanisms are well understood. In somatic tissues, the diversity of methylation patterns are only recently emerging but they are often associated with the RNA-directed DNA methylation (RdDM) pathway. Here, we discuss advances in our understanding of how the locus-specific targeting and tissue-specific expression of RdDM proteins regulate methylation patterns, how the targeting of methylation at loci with imperfect homology expands the purview of RdDM, and how natural variation within RdDM factors impacts DNA methylation patterns.
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Affiliation(s)
- Laura M Martins
- Plant Molecular and Cellular Biology Laboratory, Salk Institute for Biological Studies, La Jolla, CA, 92037, USA
| | - Julie A Law
- Plant Molecular and Cellular Biology Laboratory, Salk Institute for Biological Studies, La Jolla, CA, 92037, USA; Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA.
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8
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Yang DL, Huang K, Deng D, Zeng Y, Wang Z, Zhang Y. DNA-dependent RNA polymerases in plants. THE PLANT CELL 2023; 35:3641-3661. [PMID: 37453082 PMCID: PMC10533338 DOI: 10.1093/plcell/koad195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 06/09/2023] [Accepted: 05/29/2023] [Indexed: 07/18/2023]
Abstract
DNA-dependent RNA polymerases (Pols) transfer the genetic information stored in genomic DNA to RNA in all organisms. In eukaryotes, the typical products of nuclear Pol I, Pol II, and Pol III are ribosomal RNAs, mRNAs, and transfer RNAs, respectively. Intriguingly, plants possess two additional Pols, Pol IV and Pol V, which produce small RNAs and long noncoding RNAs, respectively, mainly for silencing transposable elements. The five plant Pols share some subunits, but their distinct functions stem from unique subunits that interact with specific regulatory factors in their transcription cycles. Here, we summarize recent advances in our understanding of plant nucleus-localized Pols, including their evolution, function, structures, and transcription cycles.
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Affiliation(s)
- Dong-Lei Yang
- National Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Kun Huang
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
| | - Deyin Deng
- State Key Laboratory of Subtropical Silviculture, School of Forestry and Biotechnology, Zhejiang Agriculture and Forestry University, Lin’an, Hangzhou 311300, China
| | - Yuan Zeng
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
| | - Zhenxing Wang
- College of Horticulture, National Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Yu Zhang
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
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9
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Zhang HW, Huang K, Gu ZX, Wu XX, Wang JW, Zhang Y. A cryo-EM structure of KTF1-bound polymerase V transcription elongation complex. Nat Commun 2023; 14:3118. [PMID: 37253723 DOI: 10.1038/s41467-023-38619-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Accepted: 05/10/2023] [Indexed: 06/01/2023] Open
Abstract
De novo DNA methylation in plants relies on transcription of RNA polymerase V (Pol V) along with KTF1, which produce long non-coding RNAs for recruitment and assembly of the DNA methylation machinery. Here, we report a cryo-EM structure of the Pol V transcription elongation complex bound to KTF1. The structure reveals the conformation of the structural motifs in the active site of Pol V that accounts for its inferior RNA-extension ability. The structure also reveals structural features of Pol V that prevent it from interacting with the transcription factors of Pol II and Pol IV. The KOW5 domain of KTF1 binds near the RNA exit channel of Pol V providing a scaffold for the proposed recruitment of Argonaute proteins to initiate the assembly of the DNA methylation machinery. The structure provides insight into the Pol V transcription elongation process and the role of KTF1 during Pol V transcription-coupled DNA methylation.
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Affiliation(s)
- Hong-Wei Zhang
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Kun Huang
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Zhan-Xi Gu
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xiao-Xian Wu
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Jia-Wei Wang
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Yu Zhang
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China.
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10
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Manavella PA, Godoy Herz MA, Kornblihtt AR, Sorenson R, Sieburth LE, Nakaminami K, Seki M, Ding Y, Sun Q, Kang H, Ariel FD, Crespi M, Giudicatti AJ, Cai Q, Jin H, Feng X, Qi Y, Pikaard CS. Beyond transcription: compelling open questions in plant RNA biology. THE PLANT CELL 2023; 35:1626-1653. [PMID: 36477566 PMCID: PMC10226580 DOI: 10.1093/plcell/koac346] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 11/14/2022] [Accepted: 12/06/2022] [Indexed: 05/30/2023]
Abstract
The study of RNAs has become one of the most influential research fields in contemporary biology and biomedicine. In the last few years, new sequencing technologies have produced an explosion of new and exciting discoveries in the field but have also given rise to many open questions. Defining these questions, together with old, long-standing gaps in our knowledge, is the spirit of this article. The breadth of topics within RNA biology research is vast, and every aspect of the biology of these molecules contains countless exciting open questions. Here, we asked 12 groups to discuss their most compelling question among some plant RNA biology topics. The following vignettes cover RNA alternative splicing; RNA dynamics; RNA translation; RNA structures; R-loops; epitranscriptomics; long non-coding RNAs; small RNA production and their functions in crops; small RNAs during gametogenesis and in cross-kingdom RNA interference; and RNA-directed DNA methylation. In each section, we will present the current state-of-the-art in plant RNA biology research before asking the questions that will surely motivate future discoveries in the field. We hope this article will spark a debate about the future perspective on RNA biology and provoke novel reflections in the reader.
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Affiliation(s)
- Pablo A Manavella
- Instituto de Agrobiotecnología del Litoral (CONICET-UNL), Cátedra de Biología Celular y Molecular, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Santa Fe 3000, Argentina
| | - Micaela A Godoy Herz
- Facultad de Ciencias Exactas y Naturales, Departamento de Fisiología, Biología Molecular y Celular and CONICET-UBA, Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), Universidad de Buenos Aires (UBA), Buenos Aires C1428EHA, Argentina
| | - Alberto R Kornblihtt
- Facultad de Ciencias Exactas y Naturales, Departamento de Fisiología, Biología Molecular y Celular and CONICET-UBA, Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), Universidad de Buenos Aires (UBA), Buenos Aires C1428EHA, Argentina
| | - Reed Sorenson
- School of Biological Sciences, University of UtahSalt Lake City 84112, USA
| | - Leslie E Sieburth
- School of Biological Sciences, University of UtahSalt Lake City 84112, USA
| | - Kentaro Nakaminami
- Center for Sustainable Resource Science, RIKEN, Kanagawa 230-0045, Japan
| | - Motoaki Seki
- Center for Sustainable Resource Science, RIKEN, Kanagawa 230-0045, Japan
- Cluster for Pioneering Research, RIKEN, Saitama 351-0198, Japan
- Kihara Institute for Biological Research, Yokohama City University, Kanagawa 244-0813, Japan
| | - Yiliang Ding
- Department of Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Qianwen Sun
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
- Tsinghua-Peking Center for Life Sciences, Beijing 100084, China
| | - Hunseung Kang
- Department of Applied Biology, College of Agriculture and Life Sciences, Chonnam National University, Gwangju 61186, Korea
| | - Federico D Ariel
- Instituto de Agrobiotecnología del Litoral (CONICET-UNL), Cátedra de Biología Celular y Molecular, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Santa Fe 3000, Argentina
| | - Martin Crespi
- Institute of Plant Sciences Paris Saclay IPS2, CNRS, INRA, Université Evry, Université Paris-Saclay, Bâtiment 630, Orsay 91405, France
- Institute of Plant Sciences Paris-Saclay IPS2, Université de Paris, Bâtiment 630, Orsay 91405, France
| | - Axel J Giudicatti
- Instituto de Agrobiotecnología del Litoral (CONICET-UNL), Cátedra de Biología Celular y Molecular, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Santa Fe 3000, Argentina
| | - Qiang Cai
- State Key Laboratory of Hybrid Rice, College of Life Science, Wuhan University, Wuhan 430072, China
| | - Hailing Jin
- Department of Microbiology and Plant Pathology and Center for Plant Cell Biology, Institute for Integrative Genome Biology, University of California, Riverside, California 92507, USA
| | - Xiaoqi Feng
- Department of Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Yijun Qi
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
- Tsinghua-Peking Center for Life Sciences, Beijing 100084, China
| | - Craig S Pikaard
- Howard Hughes Medical Institute, Department of Biology, Indiana University, Bloomington, Indiana 47405, USA
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, Indiana 47405, USA
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11
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Chow HT, Mosher RA. Small RNA-mediated DNA methylation during plant reproduction. THE PLANT CELL 2023; 35:1787-1800. [PMID: 36651080 DOI: 10.1093/plcell/koad010] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Revised: 01/11/2023] [Accepted: 01/11/2023] [Indexed: 05/30/2023]
Abstract
Reproductive tissues are a rich source of small RNAs, including several classes of short interfering (si)RNAs that are restricted to this stage of development. In addition to RNA polymerase IV-dependent 24-nt siRNAs that trigger canonical RNA-directed DNA methylation, abundant reproductive-specific siRNAs are produced from companion cells adjacent to the developing germ line or zygote and may move intercellularly before inducing methylation. In some cases, these siRNAs are produced via non-canonical biosynthesis mechanisms or from sequences with little similarity to transposons. While the precise role of these siRNAs and the methylation they trigger is unclear, they have been implicated in specifying a single megaspore mother cell, silencing transposons in the male germ line, mediating parental dosage conflict to ensure proper endosperm development, hypermethylation of mature embryos, and trans-chromosomal methylation in hybrids. In this review, we summarize the current knowledge of reproductive siRNAs, including their biosynthesis, transport, and function.
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Affiliation(s)
- Hiu Tung Chow
- The School of Plant Sciences, The University of Arizona, Tucson, Arizona 85721-0036, USA
| | - Rebecca A Mosher
- The School of Plant Sciences, The University of Arizona, Tucson, Arizona 85721-0036, USA
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12
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Xie G, Du X, Hu H, Li S, Cao X, Jacobsen SE, Du J. Structure and mechanism of the plant RNA polymerase V. Science 2023; 379:1209-1213. [PMID: 36893216 PMCID: PMC10041816 DOI: 10.1126/science.adf8231] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/11/2023]
Abstract
In addition to the conserved RNA polymerases I to III (Pols I to III) in eukaryotes, two atypical polymerases, Pols IV and V, specifically produce noncoding RNA in the RNA-directed DNA methylation pathway in plants. Here, we report on the structures of cauliflower Pol V in the free and elongation conformations. A conserved tyrosine residue of NRPE2 stacks with a double-stranded DNA branch of the transcription bubble to potentially attenuate elongation by inducing transcription stalling. The nontemplate DNA strand is captured by NRPE2 to enhance backtracking, thereby increasing 3'-5' cleavage, which likely underpins Pol V's high fidelity. The structures also illuminate the mechanism of Pol V transcription stalling and enhanced backtracking, which may be important for Pol V's retention on chromatin to serve its function in tethering downstream factors for RNA-directed DNA methylation.
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Affiliation(s)
- Guohui Xie
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, Institute of Plant and Food Science, Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China
| | - Xuan Du
- Department of Biochemistry and Molecular Biology, International Cancer Center, Shenzhen University Medical School, Shenzhen 518060, China
| | - Hongmiao Hu
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, Institute of Plant and Food Science, Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China
| | - Sisi Li
- Department of Biochemistry and Molecular Biology, International Cancer Center, Shenzhen University Medical School, Shenzhen 518060, China
| | - Xiaofeng Cao
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Steven E Jacobsen
- Department of Molecular, Cell and Developmental Biology, University of California at Los Angeles, Los Angeles, CA 90095, USA
- Howard Hughes Medical Institute, University of California at Los Angeles, Los Angeles, CA 90095, USA
| | - Jiamu Du
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, Institute of Plant and Food Science, Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China
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13
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Wang F, Huang HY, Huang J, Singh J, Pikaard CS. Enzymatic reactions of AGO4 in RNA-directed DNA methylation: siRNA duplex loading, passenger strand elimination, target RNA slicing, and sliced target retention. Genes Dev 2023; 37:103-118. [PMID: 36746605 PMCID: PMC10069450 DOI: 10.1101/gad.350240.122] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Accepted: 01/13/2023] [Indexed: 02/08/2023]
Abstract
RNA-directed DNA methylation in plants is guided by 24-nt siRNAs generated in parallel with 23-nt RNAs of unknown function. We show that 23-nt RNAs function as passenger strands during 24-nt siRNA incorporation into AGO4. The 23-nt RNAs are then sliced into 11- and 12-nt fragments, with 12-nt fragments remaining associated with AGO4. Slicing recapitulated with recombinant AGO4 and synthetic RNAs reveals that siRNAs of 21-24 nt, with any 5'-terminal nucleotide, can guide slicing, with sliced RNAs then retained by AGO4. In vivo, RdDM target locus RNAs that copurify with AGO4 also display a sequence signature of slicing. Comparing plants expressing slicing-competent versus slicing-defective AGO4 shows that slicing elevates cytosine methylation levels at virtually all RdDM loci. We propose that siRNA passenger strand elimination and AGO4 tethering to sliced target RNAs are distinct modes by which AGO4 slicing enhances RNA-directed DNA methylation.
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Affiliation(s)
- Feng Wang
- Department of Biology, Indiana University, Bloomington, Indiana 47405, USA
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, Indiana 47405, USA
- Howard Hughes Medical Institute, Indiana University, Bloomington, Indiana 47405, USA
| | - Hsiao-Yun Huang
- Department of Biology, Indiana University, Bloomington, Indiana 47405, USA
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, Indiana 47405, USA
| | - Jie Huang
- Department of Biology, Indiana University, Bloomington, Indiana 47405, USA
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, Indiana 47405, USA
| | - Jasleen Singh
- Department of Biology, Indiana University, Bloomington, Indiana 47405, USA
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, Indiana 47405, USA
| | - Craig S Pikaard
- Department of Biology, Indiana University, Bloomington, Indiana 47405, USA;
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, Indiana 47405, USA
- Howard Hughes Medical Institute, Indiana University, Bloomington, Indiana 47405, USA
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14
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Liu Y, Wang J, Liu B, Xu ZY. Dynamic regulation of DNA methylation and histone modifications in response to abiotic stresses in plants. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2022; 64:2252-2274. [PMID: 36149776 DOI: 10.1111/jipb.13368] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 09/22/2022] [Indexed: 06/16/2023]
Abstract
DNA methylation and histone modification are evolutionarily conserved epigenetic modifications that are crucial for the expression regulation of abiotic stress-responsive genes in plants. Dynamic changes in gene expression levels can result from changes in DNA methylation and histone modifications. In the last two decades, how epigenetic machinery regulates abiotic stress responses in plants has been extensively studied. Here, based on recent publications, we review how DNA methylation and histone modifications impact gene expression regulation in response to abiotic stresses such as drought, abscisic acid, high salt, extreme temperature, nutrient deficiency or toxicity, and ultraviolet B exposure. We also review the roles of epigenetic mechanisms in the formation of transgenerational stress memory. We posit that a better understanding of the epigenetic underpinnings of abiotic stress responses in plants may facilitate the design of more stress-resistant or -resilient crops, which is essential for coping with global warming and extreme environments.
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Affiliation(s)
- Yutong Liu
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun, 130024, China
| | - Jie Wang
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun, 130024, China
| | - Bao Liu
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun, 130024, China
| | - Zheng-Yi Xu
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun, 130024, China
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15
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He S, Feng X. DNA methylation dynamics during germline development. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2022; 64:2240-2251. [PMID: 36478632 PMCID: PMC10108260 DOI: 10.1111/jipb.13422] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2022] [Accepted: 12/06/2022] [Indexed: 06/17/2023]
Abstract
DNA methylation plays essential homeostatic functions in eukaryotic genomes. In animals, DNA methylation is also developmentally regulated and, in turn, regulates development. In the past two decades, huge research effort has endorsed the understanding that DNA methylation plays a similar role in plant development, especially during sexual reproduction. The power of whole-genome sequencing and cell isolation techniques, as well as bioinformatics tools, have enabled recent studies to reveal dynamic changes in DNA methylation during germline development. Furthermore, the combination of these technological advances with genetics, developmental biology and cell biology tools has revealed functional methylation reprogramming events that control gene and transposon activities in flowering plant germlines. In this review, we discuss the major advances in our knowledge of DNA methylation dynamics during male and female germline development in flowering plants.
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Affiliation(s)
- Shengbo He
- Guangdong Laboratory for Lingnan Modern Agriculture, College of AgricultureSouth China Agricultural UniversityGuangzhou510642China
| | - Xiaoqi Feng
- John Innes Centre, Colney LaneNorwichNR4 7UHUK
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16
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Zhang H, Gao J, Chen J, Peng Y, Han Z. RNA-dependent RNA polymerase could extend the lasting validity period of exogenous dsRNA. PEST MANAGEMENT SCIENCE 2022; 78:4569-4578. [PMID: 35831266 DOI: 10.1002/ps.7076] [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: 11/24/2021] [Revised: 07/04/2022] [Accepted: 07/13/2022] [Indexed: 06/15/2023]
Abstract
BACKGROUND Previous studies have found that pesticide double-stranded (ds)RNA usually has a long-lasting validity period in plants. However, it is uncertain if any factors in plants could extend dsRNA duration. It has been reported that RNA-dependent RNA polymerases (RdRP) in plants and some other eukaryotes could catalyze RNA amplification and be involved in RNAi (interference). Thus, this study evaluated the effect of RdRP on the tissue content, activity, and duration of exogenous dsRNA. RESULTS We found that RdRP knockdown in Arabidopsis thaliana had no significant effect on tissue contents of reporter dsRNA parent molecules (8.91% reduction), but it caused significant decrease in the tissue contents of derived short fragments of 200, 120 and 59 bp tested (51.22%, 52.83% and 59.35%, respectively). Aphid inoculation tests showed that the same dose of insecticidal dsAgZFP exhibited a significantly lower lethal effect (mortality 58.8%) in the plants with RdRP knockdown than in the control plants with normal RdRP (86.0%). For Caenorhabditis elegans, the worms treated simultaneously with dsRdRP and reporter dsRNA had similar body contents to reporter dsRNA parent molecules and its long-fragment derivative (200 bp) as the control (1.28- and 1.07-fold greater, respectively). However, 120- and 59-bp short-fragment derivatives were significantly reduced by 28.78% and 59.84%, respectively, which also diminished faster in the descendants. CONCLUSIONS We conclude that RdRP could significantly enhance the tissue content of dsRNA derivatives by catalyzing amplification, thus improving dsRNA activity and extending its lasting validity period. Otherwise, RNAi by exogenous dsRNA was proven to be noninheritable in A. thaliana. This work confirmed the merit of dsRNA as a plant protectant. © 2022 Society of Chemical Industry.
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Affiliation(s)
- Hainan Zhang
- The Key Laboratory of Monitoring and Management of Plant Diseases and Insects/Department of Entomology, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Jing Gao
- The Key Laboratory of Monitoring and Management of Plant Diseases and Insects/Department of Entomology, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Jiasheng Chen
- The Key Laboratory of Monitoring and Management of Plant Diseases and Insects/Department of Entomology, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
- School of Plant Protection, Anhui Agricultural University, Hefei, China
| | - Yue Peng
- The Key Laboratory of Monitoring and Management of Plant Diseases and Insects/Department of Entomology, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Zhaojun Han
- The Key Laboratory of Monitoring and Management of Plant Diseases and Insects/Department of Entomology, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
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17
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Zhang H, Chen J, Gao J, Zhang Q, Liu X, Han Z. New insights into transmission pathways and possible off-target effects of insecticidal dsRNA released by treated plants. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2022; 188:105281. [PMID: 36464336 DOI: 10.1016/j.pestbp.2022.105281] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 09/29/2022] [Accepted: 11/02/2022] [Indexed: 06/17/2023]
Abstract
RNAi has shown great potential in controlling pests and pathogens, and dsRNA-based pesticides have been used in different ways. Due to off-target effects, the transmission pathways and possible impacts of dsRNA on non-target organisms after release should be researched. Here, we tested pathways of dsRNA transmission through the rice-hopper-spider food chain and their efficiency for triggering RNAi. The results revealed five new pathways by which plants transfer dsRNA into the environment through the food chain. We found that ingestion of the tissues or guttation droplets of treated plant could trigger both targeted and off-target RNAi both in consumers and predators. Ingestion of consumer hoppers could also result in localized RNAi in the midguts of the predator spiders. Trace amounts of dsRNA were detected in plant root excretions and in hopper honeydew. Cutting the root tips dramatically increased the levels of dsRNA in root excretions. Host shifting experiments proved that hoppers could transfer a trace amount of dsRNA via vomit. With specially designed dsRNAs, we showed that dsRNA sharing matching sequences of 29 bp or 32 bp in length with non-target genes could trigger off-target RNAi, but that dsRNA sharing 13 bp matching sequences could not. We conclude that field-released pesticidal dsRNA could be transmitted via the hydrophilic transport system in plants, and that this may pose a safety risk to non-target animal consumers that are closely related to target pests. Rational use of pesticidal dsRNAs should involve careful consideration of dsRNA design to manage the biosafety risk.
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Affiliation(s)
- Hainan Zhang
- The Key Laboratory of Monitoring and Management of Plant Diseases and Insects/Department of Entomology, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China
| | - Jiasheng Chen
- The Key Laboratory of Monitoring and Management of Plant Diseases and Insects/Department of Entomology, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China; School of Plant Protection, Anhui Agricultural University, Hefei 230036, China
| | - Jing Gao
- The Key Laboratory of Monitoring and Management of Plant Diseases and Insects/Department of Entomology, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China
| | - Qi Zhang
- The Key Laboratory of Monitoring and Management of Plant Diseases and Insects/Department of Entomology, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China
| | - Xiaolong Liu
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan 430062, China
| | - Zhaojun Han
- The Key Laboratory of Monitoring and Management of Plant Diseases and Insects/Department of Entomology, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China.
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18
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Chakraborty T, Payne H, Mosher RA. Expansion and contraction of small RNA and methylation machinery throughout plant evolution. CURRENT OPINION IN PLANT BIOLOGY 2022; 69:102260. [PMID: 35849937 DOI: 10.1016/j.pbi.2022.102260] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 06/09/2022] [Accepted: 06/14/2022] [Indexed: 06/15/2023]
Abstract
The revolution in sequencing has created a wealth of plant genomes that can be mined to understand the evolution of biological complexity. Complexity is often driven by gene duplication, which allows paralogs to specialize in an activity of the ancestral gene or acquire novel functions. Angiosperms encode a variety of gene silencing pathways that share related machinery for small RNA biosynthesis and function. Recent phylogenetic analysis of these gene families plots the expansion, specialization, and occasional contraction of this core machinery. This analysis reveals the ancient origin of RNA-directed DNA Methylation in early land plants, or possibly their algal ancestors, as well as ongoing duplications that evolve novel small RNA pathways.
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Affiliation(s)
- Tania Chakraborty
- School of Plant Sciences, University of Arizona, Tucson, AZ 85721-0036, USA
| | - Hayden Payne
- School of Plant Sciences, University of Arizona, Tucson, AZ 85721-0036, USA
| | - Rebecca A Mosher
- School of Plant Sciences, University of Arizona, Tucson, AZ 85721-0036, USA.
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19
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Cui R, Li H, Zhao J, Li X, Gan J, Ma J. Structural insights into the dual activities of the two-barrel RNA polymerase QDE-1. Nucleic Acids Res 2022; 50:10169-10186. [PMID: 36039765 PMCID: PMC9508822 DOI: 10.1093/nar/gkac727] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 08/01/2022] [Accepted: 08/27/2022] [Indexed: 11/19/2022] Open
Abstract
Neurospora crassa protein QDE-1, a member of the two-barrel polymerase superfamily, possesses both DNA- and RNA-dependent RNA polymerase (DdRP and RdRP) activities. The dual activities are essential for the production of double-stranded RNAs (dsRNAs), the precursors of small interfering RNAs (siRNAs) in N. crassa. Here, we report five complex structures of N-terminal truncated QDE-1 (QDE-1ΔN), representing four different reaction states: DNA/RNA-templated elongation, the de novo initiation of RNA synthesis, the first step of nucleotide condensation during de novo initiation and initial NTP loading. The template strand is aligned by a bridge-helix and double-psi beta-barrels 2 (DPBB2), the RNA product is held by DPBB1 and the slab domain. The DNA template unpairs with the RNA product at position –7, but the RNA template remains paired. The NTP analog coordinates with cations and is precisely positioned at the addition site by a rigid trigger loop and a proline-containing loop in the active center. The unique C-terminal tail from the QDE-1 dimer partner inserts into the substrate-binding cleft and plays regulatory roles in RNA synthesis. Collectively, this work elucidates the conserved mechanisms for DNA/RNA-dependent dual activities by QDE-1 and other two-barrel polymerase superfamily members.
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Affiliation(s)
- Ruixue Cui
- Huashan Hospital affiliated to Fudan University, State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Multiscale Research Institute of Complex Systems, Department of Biochemistry and Biophysics, School of Life Sciences, Fudan University, Shanghai 200438, China
| | - Hao Li
- Huashan Hospital affiliated to Fudan University, State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Multiscale Research Institute of Complex Systems, Department of Biochemistry and Biophysics, School of Life Sciences, Fudan University, Shanghai 200438, China
| | - Jin Zhao
- Huashan Hospital affiliated to Fudan University, State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Multiscale Research Institute of Complex Systems, Department of Biochemistry and Biophysics, School of Life Sciences, Fudan University, Shanghai 200438, China
| | - Xuhang Li
- Huashan Hospital affiliated to Fudan University, State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Multiscale Research Institute of Complex Systems, Department of Biochemistry and Biophysics, School of Life Sciences, Fudan University, Shanghai 200438, China
| | - Jianhua Gan
- Shanghai Public Health Clinical Center, State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Department of Biochemistry and Biophysics, School of Life Sciences, Fudan University, Shanghai 200438, China
| | - Jinbiao Ma
- Huashan Hospital affiliated to Fudan University, State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Multiscale Research Institute of Complex Systems, Department of Biochemistry and Biophysics, School of Life Sciences, Fudan University, Shanghai 200438, China
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20
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Zicola J. RDR2 in maize: one-way road to double-stranded RNA. THE PLANT CELL 2022; 34:2104-2105. [PMID: 35362529 PMCID: PMC9134046 DOI: 10.1093/plcell/koac100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Accepted: 03/21/2022] [Indexed: 06/14/2023]
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21
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Du X, Yang Z, Ariza AJF, Wang Q, Xie G, Li S, Du J. Structure of plant RNA-DEPENDENT RNA POLYMERASE 2, an enzyme involved in small interfering RNA production. THE PLANT CELL 2022; 34:2140-2149. [PMID: 35188193 PMCID: PMC9134047 DOI: 10.1093/plcell/koac067] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 02/10/2022] [Indexed: 06/14/2023]
Abstract
In plants, the biogenesis of small interfering RNA (siRNA) requires a family of RNA-dependent RNA polymerases that convert single-stranded RNA (ssRNA) into double-stranded RNA (dsRNA), which is subsequently cleaved into defined lengths by Dicer endonucleases. Here, we determined the structure of maize (Zea mays) RNA-DEPENDENT RNA POLYMERASE 2 (ZmRDR2) in the closed and open conformations. The core catalytic region of ZmRDR2 possesses the canonical DNA-dependent RNA polymerase (DdRP) catalytic sites, pointing to a shared RNA production mechanism between DdRPs and plant RDR-family proteins. Apo-ZmRDR2 adopts a highly compact structure, representing an inactive closed conformation. By contrast, adding RNA induced a significant conformational change in the ZmRDR2 Head domain that opened the RNA binding tunnel, suggesting this is an active elongation conformation of ZmRDR2. Overall, our structural studies trapped both the active and inactive conformations of ZmRDR2, providing insights into the molecular mechanism of dsRNA synthesis during plant siRNA production.
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Affiliation(s)
| | | | - Alfredo Jose Florez Ariza
- California Institute for Quantitative Biosciences (QB3), University of California, Berkeley, California 94720, USA
- Biophysics Graduate Group, University of California, Berkeley, California 94720, USA
| | - Qian Wang
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, Institute of Plant and Food Science, Department of Biology, School of Life Science, Southern University of Science and Technology, Shenzhen 518055, China
| | - Guohui Xie
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, Institute of Plant and Food Science, Department of Biology, School of Life Science, Southern University of Science and Technology, Shenzhen 518055, China
| | - Sisi Li
- Department of Biochemistry and Molecular Biology, International Cancer Center, Shenzhen University Health Science Center, Shenzhen 518060, China
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22
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Gardiner J, Ghoshal B, Wang M, Jacobsen SE. CRISPR-Cas-mediated transcriptional control and epi-mutagenesis. PLANT PHYSIOLOGY 2022; 188:1811-1824. [PMID: 35134247 PMCID: PMC8968285 DOI: 10.1093/plphys/kiac033] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Accepted: 01/13/2022] [Indexed: 05/24/2023]
Abstract
Tools for sequence-specific DNA binding have opened the door to new approaches in investigating fundamental questions in biology and crop development. While there are several platforms to choose from, many of the recent advances in sequence-specific targeting tools are focused on developing Clustered Regularly Interspaced Short Palindromic Repeats- CRISPR Associated (CRISPR-Cas)-based systems. Using a catalytically inactive Cas protein (dCas), this system can act as a vector for different modular catalytic domains (effector domains) to control a gene's expression or alter epigenetic marks such as DNA methylation. Recent trends in developing CRISPR-dCas systems include creating versions that can target multiple copies of effector domains to a single site, targeting epigenetic changes that, in some cases, can be inherited to the next generation in the absence of the targeting construct, and combining effector domains and targeting strategies to create synergies that increase the functionality or efficiency of the system. This review summarizes and compares DNA targeting technologies, the effector domains used to target transcriptional control and epi-mutagenesis, and the different CRISPR-dCas systems used in plants.
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Affiliation(s)
| | | | - Ming Wang
- Department of Molecular, Cell and Developmental Biology, University of California at Los Angeles, Los Angeles, California, USA
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23
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Jin L, Chen M, Xiang M, Guo Z. RNAi-Based Antiviral Innate Immunity in Plants. Viruses 2022; 14:v14020432. [PMID: 35216025 PMCID: PMC8875485 DOI: 10.3390/v14020432] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 02/17/2022] [Accepted: 02/18/2022] [Indexed: 12/13/2022] Open
Abstract
Multiple antiviral immunities were developed to defend against viral infection in hosts. RNA interference (RNAi)-based antiviral innate immunity is evolutionarily conserved in eukaryotes and plays a vital role against all types of viruses. During the arms race between the host and virus, many viruses evolve viral suppressors of RNA silencing (VSRs) to inhibit antiviral innate immunity. Here, we reviewed the mechanism at different stages in RNAi-based antiviral innate immunity in plants and the counteractions of various VSRs, mainly upon infection of RNA viruses in model plant Arabidopsis. Some critical challenges in the field were also proposed, and we think that further elucidating conserved antiviral innate immunity may convey a broad spectrum of antiviral strategies to prevent viral diseases in the future.
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24
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Agapov A, Olina A, Kulbachinskiy A. OUP accepted manuscript. Nucleic Acids Res 2022; 50:3018-3041. [PMID: 35323981 PMCID: PMC8989532 DOI: 10.1093/nar/gkac174] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2021] [Revised: 02/26/2022] [Accepted: 03/03/2022] [Indexed: 11/14/2022] Open
Abstract
Cellular DNA is continuously transcribed into RNA by multisubunit RNA polymerases (RNAPs). The continuity of transcription can be disrupted by DNA lesions that arise from the activities of cellular enzymes, reactions with endogenous and exogenous chemicals or irradiation. Here, we review available data on translesion RNA synthesis by multisubunit RNAPs from various domains of life, define common principles and variations in DNA damage sensing by RNAP, and consider existing controversies in the field of translesion transcription. Depending on the type of DNA lesion, it may be correctly bypassed by RNAP, or lead to transcriptional mutagenesis, or result in transcription stalling. Various lesions can affect the loading of the templating base into the active site of RNAP, or interfere with nucleotide binding and incorporation into RNA, or impair RNAP translocation. Stalled RNAP acts as a sensor of DNA damage during transcription-coupled repair. The outcome of DNA lesion recognition by RNAP depends on the interplay between multiple transcription and repair factors, which can stimulate RNAP bypass or increase RNAP stalling, and plays the central role in maintaining the DNA integrity. Unveiling the mechanisms of translesion transcription in various systems is thus instrumental for understanding molecular pathways underlying gene regulation and genome stability.
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Affiliation(s)
- Aleksei Agapov
- Correspondence may also be addressed to Aleksei Agapov. Tel: +7 499 196 0015; Fax: +7 499 196 0015;
| | - Anna Olina
- Institute of Molecular Genetics, National Research Center “Kurchatov Institute” Moscow 123182, Russia
| | - Andrey Kulbachinskiy
- To whom correspondence should be addressed. Tel: +7 499 196 0015; Fax: +7 499 196 0015;
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