1
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Busetto V, Pshanichnaya L, Lichtenberger R, Hann S, Ketting RF, Falk S. MUT-7 exoribonuclease activity and localization are mediated by an ancient domain. Nucleic Acids Res 2024; 52:9076-9091. [PMID: 39188014 DOI: 10.1093/nar/gkae610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Revised: 06/18/2024] [Accepted: 06/28/2024] [Indexed: 08/28/2024] Open
Abstract
The MUT-7 family of 3'-5' exoribonucleases is evolutionarily conserved across the animal kingdom and plays essential roles in small RNA production in the germline. Most MUT-7 homologues carry a C-terminal domain of unknown function named MUT7-C appended to the exoribonuclease domain. Our analysis shows that the MUT7-C is evolutionary ancient, as a minimal version of the domain exists as an individual protein in prokaryotes. In animals, MUT7-C has acquired an insertion that diverged during evolution, expanding its functions. Caenorhabditis elegans MUT-7 contains a specific insertion within MUT7-C, which allows binding to MUT-8 and, consequently, MUT-7 recruitment to germ granules. In addition, in C. elegans and human MUT-7, the MUT7-C domain contributes to RNA binding and is thereby crucial for ribonuclease activity. This RNA-binding function most likely represents the ancestral function of the MUT7-C domain. Overall, this study sheds light on MUT7-C and assigns two functions to this previously uncharacterized domain.
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Affiliation(s)
- Virginia Busetto
- Max Perutz Labs, Vienna Biocenter Campus (VBC), Dr.-Bohr-Gasse 9, 1030 Vienna, Austria
- Department of Structural and Computational Biology, Max Perutz Labs, University of Vienna, Campus Vienna Biocenter 5, 1030 Vienna, Austria
| | - Lizaveta Pshanichnaya
- Biology of Non-coding RNA Group, Institute of Molecular Biology, Ackermannweg 4, 55128 Mainz, Germany
- International PhD Programme on Gene Regulation, Epigenetics & Genome Stability, Mainz, Germany
| | - Raffael Lichtenberger
- Max Perutz Labs, Vienna Biocenter Campus (VBC), Dr.-Bohr-Gasse 9, 1030 Vienna, Austria
- Department of Structural and Computational Biology, Max Perutz Labs, University of Vienna, Campus Vienna Biocenter 5, 1030 Vienna, Austria
| | - Stephan Hann
- Institute of Analytical Chemistry, Department of Chemistry, University of Natural Resources and Life Sciences, Vienna, Muthgasse 18, 1190 Vienna, Austria
| | - René F Ketting
- Biology of Non-coding RNA Group, Institute of Molecular Biology, Ackermannweg 4, 55128 Mainz, Germany
- Institute of Developmental Biology and Neurobiology, Johannes Gutenberg University, 55099Mainz, Germany
| | - Sebastian Falk
- Max Perutz Labs, Vienna Biocenter Campus (VBC), Dr.-Bohr-Gasse 9, 1030 Vienna, Austria
- Department of Structural and Computational Biology, Max Perutz Labs, University of Vienna, Campus Vienna Biocenter 5, 1030 Vienna, Austria
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2
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Jose AM. Heritable epigenetic changes are constrained by the dynamics of regulatory architectures. eLife 2024; 12:RP92093. [PMID: 38717010 PMCID: PMC11078544 DOI: 10.7554/elife.92093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/12/2024] Open
Abstract
Interacting molecules create regulatory architectures that can persist despite turnover of molecules. Although epigenetic changes occur within the context of such architectures, there is limited understanding of how they can influence the heritability of changes. Here, I develop criteria for the heritability of regulatory architectures and use quantitative simulations of interacting regulators parsed as entities, their sensors, and the sensed properties to analyze how architectures influence heritable epigenetic changes. Information contained in regulatory architectures grows rapidly with the number of interacting molecules and its transmission requires positive feedback loops. While these architectures can recover after many epigenetic perturbations, some resulting changes can become permanently heritable. Architectures that are otherwise unstable can become heritable through periodic interactions with external regulators, which suggests that mortal somatic lineages with cells that reproducibly interact with the immortal germ lineage could make a wider variety of architectures heritable. Differential inhibition of the positive feedback loops that transmit regulatory architectures across generations can explain the gene-specific differences in heritable RNA silencing observed in the nematode Caenorhabditis elegans. More broadly, these results provide a foundation for analyzing the inheritance of epigenetic changes within the context of the regulatory architectures implemented using diverse molecules in different living systems.
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3
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Deans NC, Talbot JERB, Li M, Sáez-González C, Hövel I, Heavens D, Stam M, Hollick JB. Paramutation at the maize pl1 locus is associated with RdDM activity at distal tandem repeats. PLoS Genet 2024; 20:e1011296. [PMID: 38814980 PMCID: PMC11166354 DOI: 10.1371/journal.pgen.1011296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Revised: 06/11/2024] [Accepted: 05/08/2024] [Indexed: 06/01/2024] Open
Abstract
Exceptions to Mendelian inheritance often highlight novel chromosomal behaviors. The maize Pl1-Rhoades allele conferring plant pigmentation can display inheritance patterns deviating from Mendelian expectations in a behavior known as paramutation. However, the chromosome features mediating such exceptions remain unknown. Here we show that small RNA production reflecting RNA polymerase IV function within a distal downstream set of five tandem repeats is coincident with meiotically-heritable repression of the Pl1-Rhoades transcription unit. A related pl1 haplotype with three, but not one with two, repeat units also displays the trans-homolog silencing typifying paramutations. 4C interactions, CHD3a-dependent small RNA profiles, nuclease sensitivity, and polyadenylated RNA levels highlight a repeat subregion having regulatory potential. Our comparative and mutant analyses show that transcriptional repression of Pl1-Rhoades correlates with 24-nucleotide RNA production and cytosine methylation at this subregion indicating the action of a specific DNA-dependent RNA polymerase complex. These findings support a working model in which pl1 paramutation depends on trans-chromosomal RNA-directed DNA methylation operating at a discrete cis-linked and copy-number-dependent transcriptional regulatory element.
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Affiliation(s)
- Natalie C. Deans
- Department of Molecular Genetics, The Ohio State University, Columbus, Ohio, United States of America
- Centers for Applied Plant Sciences and RNA Biology, The Ohio State University, Columbus, Ohio, United States of America
| | - Joy-El R. B. Talbot
- Department of Molecular Genetics, The Ohio State University, Columbus, Ohio, United States of America
- Department of Molecular and Cell Biology, University of California Berkeley, Berkeley, California, United States of America
| | - Mowei Li
- Department of Molecular Genetics, The Ohio State University, Columbus, Ohio, United States of America
- Centers for Applied Plant Sciences and RNA Biology, The Ohio State University, Columbus, Ohio, United States of America
| | - Cristian Sáez-González
- Department of Molecular Genetics, The Ohio State University, Columbus, Ohio, United States of America
| | - Iris Hövel
- Swammerdam Institute for Life Sciences, Universiteit van Amsterdam, Amsterdam, The Netherlands
| | | | - Maike Stam
- Swammerdam Institute for Life Sciences, Universiteit van Amsterdam, Amsterdam, The Netherlands
| | - Jay B. Hollick
- Department of Molecular Genetics, The Ohio State University, Columbus, Ohio, United States of America
- Centers for Applied Plant Sciences and RNA Biology, The Ohio State University, Columbus, Ohio, United States of America
- Department of Plant and Microbial Biology, University of California, Berkeley, California, United States of America
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4
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Pastore B, Hertz HL, Tang W. Pre-piRNA trimming safeguards piRNAs against erroneous targeting by RNA-dependent RNA polymerase. Cell Rep 2024; 43:113692. [PMID: 38244197 PMCID: PMC10949418 DOI: 10.1016/j.celrep.2024.113692] [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: 11/03/2023] [Revised: 12/13/2023] [Accepted: 01/04/2024] [Indexed: 01/22/2024] Open
Abstract
The Piwi/Piwi-interacting RNA (piRNA) pathway protects genome integrity in animal germ lines. Maturation of piRNAs involves nucleolytic processing at both 5' and 3' ends. The ribonuclease PARN-1 and its orthologs mediate piRNA 3' trimming in worms, insects, and mammals. However, the significance of this evolutionarily conserved processing step is not fully understood. Employing C. elegans as a model, we recently discovered that 3' trimming protects piRNAs against non-templated nucleotide additions and degradation. Here, we find that worms lacking PARN-1 accumulate an uncharacterized RNA species termed anti-piRNAs, which are antisense to piRNAs. Anti-piRNAs associate with Piwi proteins, are 17-19 nucleotides long, and begin with 5' guanine or adenine. Untrimmed pre-piRNAs are misdirected by the terminal nucleotidyltransferase RDE-3 and RNA-dependent RNA polymerase EGO-1, leading to the formation of anti-piRNAs. This work identifies a class of small RNAs in parn-1 mutants and provides insight into the activities of RDE-3, EGO-1, and Piwi proteins.
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Affiliation(s)
- Benjamin Pastore
- Department of Biological Chemistry and Pharmacology, The Ohio State University, Columbus, OH 43210, USA; Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA; Ohio State Biochemistry Program, The Ohio State University, Columbus, OH 43210, USA
| | - Hannah L Hertz
- Department of Biological Chemistry and Pharmacology, The Ohio State University, Columbus, OH 43210, USA; Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA
| | - Wen Tang
- Department of Biological Chemistry and Pharmacology, The Ohio State University, Columbus, OH 43210, USA; Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA; Ohio State Biochemistry Program, The Ohio State University, Columbus, OH 43210, USA.
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5
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Ow MC, Hall SE. Inheritance of Stress Responses via Small Non-Coding RNAs in Invertebrates and Mammals. EPIGENOMES 2023; 8:1. [PMID: 38534792 DOI: 10.3390/epigenomes8010001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Revised: 12/06/2023] [Accepted: 12/12/2023] [Indexed: 03/28/2024] Open
Abstract
While reports on the generational inheritance of a parental response to stress have been widely reported in animals, the molecular mechanisms behind this phenomenon have only recently emerged. The booming interest in epigenetic inheritance has been facilitated in part by the discovery that small non-coding RNAs are one of its principal conduits. Discovered 30 years ago in the Caenorhabditis elegans nematode, these small molecules have since cemented their critical roles in regulating virtually all aspects of eukaryotic development. Here, we provide an overview on the current understanding of epigenetic inheritance in animals, including mice and C. elegans, as it pertains to stresses such as temperature, nutritional, and pathogenic encounters. We focus on C. elegans to address the mechanistic complexity of how small RNAs target their cohort mRNAs to effect gene expression and how they govern the propagation or termination of generational perdurance in epigenetic inheritance. Presently, while a great amount has been learned regarding the heritability of gene expression states, many more questions remain unanswered and warrant further investigation.
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Affiliation(s)
- Maria C Ow
- Department of Biology, Syracuse University, Syracuse, NY 13210, USA
| | - Sarah E Hall
- Department of Biology and Program in Neuroscience, Syracuse University, Syracuse, NY 13210, USA
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6
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Escobar CA, Petersen RJ, Tonelli M, Fan L, Henzler-Wildman KA, Butcher SE. Solution Structure of Poly(UG) RNA. J Mol Biol 2023; 435:168340. [PMID: 37924862 PMCID: PMC10841838 DOI: 10.1016/j.jmb.2023.168340] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Revised: 10/27/2023] [Accepted: 10/29/2023] [Indexed: 11/06/2023]
Abstract
Poly(UG) or "pUG" RNAs are UG or GU dinucleotide repeat sequences which are highly abundant in eukaryotes. Post-transcriptional addition of pUGs to RNA 3' ends marks mRNAs as vectors for gene silencing in C. elegans. We previously determined the crystal structure of pUG RNA bound to the ligand N-methyl mesoporphyrin IX (NMM), but the structure of free pUG RNA is unknown. Here we report the solution structure of the free pUG RNA (GU)12, as determined by nuclear magnetic resonance spectroscopy and small and wide-angle x-ray scattering (NMR-SAXS-WAXS). The low complexity sequence and 4-fold symmetry of the structure result in overlapped NMR signals that complicate chemical shift assignment. We therefore utilized single site-specific deoxyribose modifications which did not perturb the structure and introduced well-resolved methylene signals that are easily identified in NMR spectra. The solution structure ensemble has a root mean squared deviation (RMSD) of 0.62 Å and is a compact, left-handed quadruplex with a Z-form backbone, or "pUG fold." Overall, the structure agrees with the crystal structure of (GU)12 bound to NMM, indicating the pUG fold is unaltered by docking of the NMM ligand. The solution structure reveals conformational details that could not be resolved by x-ray crystallography, which explain how the pUG fold can form within longer RNAs.
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Affiliation(s)
- Cristian A Escobar
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, USA
| | - Riley J Petersen
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, USA
| | - Marco Tonelli
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, USA; National Magnetic Resonance Facility at Madison, University of Wisconsin-Madison, Madison, WI, USA
| | - Lixin Fan
- Basic Science Program, Frederick National Laboratory for Cancer Research, SAXS Core Facility of National Cancer Institute, Frederick, MD, USA
| | - Katherine A Henzler-Wildman
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, USA; National Magnetic Resonance Facility at Madison, University of Wisconsin-Madison, Madison, WI, USA
| | - Samuel E Butcher
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, USA; National Magnetic Resonance Facility at Madison, University of Wisconsin-Madison, Madison, WI, USA.
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7
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Pastore B, Hertz HL, Tang W. Pre-piRNA trimming safeguards piRNAs against erroneous targeting by RNA-dependent RNA Polymerase. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.26.559619. [PMID: 37808652 PMCID: PMC10557677 DOI: 10.1101/2023.09.26.559619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/10/2023]
Abstract
In animal germ lines, The Piwi/piRNA pathway plays a crucial role in safeguarding genome integrity and promoting fertility. Following transcription from discrete genomic loci, piRNA precursors undergo nucleolytic processing at both 5' and 3' ends. The ribonuclease PARN-1 and its orthologs mediate piRNA 3' trimming in worms, insects and mammals. Yet, the significance of this evolutionarily conserved processing step is not well understood. Employing C. elegans as a model organism, our recent work has demonstrated that 3' trimming protects piRNAs against non-templated nucleotide additions and degradation. In this study, we present an unexpected finding that C. elegans deficient for PARN-1 accumulate a heretofore uncharacterized RNA species termed anti-piRNAs, which are antisense to piRNAs. These anti-piRNAs associate with Piwi proteins and display the propensity for a length of 17-19 nucleotides and 5' guanine and adenine residues. We show that untrimmed pre-piRNAs in parn-1 mutants are modified by the terminal nucleotidyltransferase RDE-3 and erroneously targeted by the RNA-dependent RNA polymerase EGO-1, thereby giving rise to anti-piRNAs. Taken together, our work identifies a previously unknown class of small RNAs upon loss of parn-1 and provides mechanistic insight to activities of RDE-3, EGO-1 and Piwi proteins.
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8
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Price IF, Wagner JA, Pastore B, Hertz HL, Tang W. C. elegans germ granules sculpt both germline and somatic RNAome. Nat Commun 2023; 14:5965. [PMID: 37749091 PMCID: PMC10520050 DOI: 10.1038/s41467-023-41556-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2023] [Accepted: 09/08/2023] [Indexed: 09/27/2023] Open
Abstract
Germ granules are membrane-less organelles essential for small RNA biogenesis and germline development. Among the conserved properties of germ granules is their association with the nuclear membrane. Recent studies demonstrated that LOTUS domain proteins, EGGD-1 and EGGD-2 (also known as MIP-1 and MIP-2 respectively), promote the formation of perinuclear germ granules in C. elegans. This finding presents a unique opportunity to evaluate the significance of perinuclear localization of germ granules. Here we show that loss of eggd-1 causes the coalescence of germ granules and formation of abnormal cytoplasmic aggregates. Impairment of perinuclear granules affects certain germline classes of small RNAs including Piwi-interacting RNAs. Transcriptome profiling reveals overexpression of spermatogenic and cuticle-related genes in eggd-1 hermaphrodites. We further demonstrate that disruption of germ granules activates HLH-30-mediated transcriptional program in somatic tissues. Collectively, our findings underscore the essential role of EGGD-1 in germ granule organization and reveal an unexpected germ granule-to-soma communication.
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Affiliation(s)
- Ian F Price
- Department of Biological Chemistry and Pharmacology, The Ohio State University, Columbus, OH, 43210, USA
- Center for RNA Biology, The Ohio State University, Columbus, OH, 43210, USA
- Ohio State Biochemistry Program, The Ohio State University, Columbus, OH, 43210, USA
| | - Jillian A Wagner
- Department of Biological Chemistry and Pharmacology, The Ohio State University, Columbus, OH, 43210, USA
- Center for RNA Biology, The Ohio State University, Columbus, OH, 43210, USA
| | - Benjamin Pastore
- Department of Biological Chemistry and Pharmacology, The Ohio State University, Columbus, OH, 43210, USA
- Center for RNA Biology, The Ohio State University, Columbus, OH, 43210, USA
- Ohio State Biochemistry Program, The Ohio State University, Columbus, OH, 43210, USA
| | - Hannah L Hertz
- Department of Biological Chemistry and Pharmacology, The Ohio State University, Columbus, OH, 43210, USA
- Center for RNA Biology, The Ohio State University, Columbus, OH, 43210, USA
| | - Wen Tang
- Department of Biological Chemistry and Pharmacology, The Ohio State University, Columbus, OH, 43210, USA.
- Center for RNA Biology, The Ohio State University, Columbus, OH, 43210, USA.
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9
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Wang X, Ramat A, Simonelig M, Liu MF. Emerging roles and functional mechanisms of PIWI-interacting RNAs. Nat Rev Mol Cell Biol 2023; 24:123-141. [PMID: 36104626 DOI: 10.1038/s41580-022-00528-0] [Citation(s) in RCA: 61] [Impact Index Per Article: 61.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/01/2022] [Indexed: 02/02/2023]
Abstract
PIWI-interacting RNAs (piRNAs) are a class of small non-coding RNAs that associate with proteins of the PIWI clade of the Argonaute family. First identified in animal germ line cells, piRNAs have essential roles in germ line development. The first function of PIWI-piRNA complexes to be described was the silencing of transposable elements, which is crucial for maintaining the integrity of the germ line genome. Later studies provided new insights into the functions of PIWI-piRNA complexes by demonstrating that they regulate protein-coding genes. Recent studies of piRNA biology, including in new model organisms such as golden hamsters, have deepened our understanding of both piRNA biogenesis and piRNA function. In this Review, we discuss the most recent advances in our understanding of piRNA biogenesis, the molecular mechanisms of piRNA function and the emerging roles of piRNAs in germ line development mainly in flies and mice, and in infertility, cancer and neurological diseases in humans.
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Affiliation(s)
- Xin Wang
- State Key Laboratory of Molecular Biology, Shanghai Key Laboratory of Molecular Andrology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, China.,Key Laboratory of Systems Health Science of Zhejiang Province, School of Life Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou, China
| | - Anne Ramat
- Institute of Human Genetics, University of Montpellier, CNRS, Montpellier, France
| | - Martine Simonelig
- Institute of Human Genetics, University of Montpellier, CNRS, Montpellier, France.
| | - Mo-Fang Liu
- State Key Laboratory of Molecular Biology, Shanghai Key Laboratory of Molecular Andrology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, China. .,Key Laboratory of Systems Health Science of Zhejiang Province, School of Life Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou, China. .,School of Life Science and Technology, Shanghai Tech University, Shanghai, China.
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10
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Karin O, Miska EA, Simons BD. Epigenetic inheritance of gene silencing is maintained by a self-tuning mechanism based on resource competition. Cell Syst 2023; 14:24-40.e11. [PMID: 36657390 PMCID: PMC7614883 DOI: 10.1016/j.cels.2022.12.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 09/05/2022] [Accepted: 12/12/2022] [Indexed: 01/19/2023]
Abstract
Biological systems can maintain memories over long timescales, with examples including memories in the brain and immune system. It is unknown how functional properties of memory systems, such as memory persistence, can be established by biological circuits. To address this question, we focus on transgenerational epigenetic inheritance in Caenorhabditis elegans. In response to a trigger, worms silence a target gene for multiple generations, resisting strong dilution due to growth and reproduction. Silencing may also be maintained indefinitely upon selection according to silencing levels. We show that these properties imply the fine-tuning of biochemical rates in which the silencing system is positioned near the transition to bistability. We demonstrate that this behavior is consistent with a generic mechanism based on competition for synthesis resources, which leads to self-organization around a critical state with broad silencing timescales. The theory makes distinct predictions and offers insights into the design principles of long-term memory systems.
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Affiliation(s)
- Omer Karin
- Department of Applied Mathematics and Theoretical Physics, Centre for Mathematical Sciences, University of Cambridge, Cambridge, CB3 0WA, UK; Wellcome Trust, Cancer Research UK Gurdon Institute, University of Cambridge, Cambridge, CB2 1QN, UK; Department of Mathematics, Imperial College London, London, SW7 2AZ, UK.
| | - Eric A Miska
- Wellcome Trust, Cancer Research UK Gurdon Institute, University of Cambridge, Cambridge, CB2 1QN, UK; Department of Genetics, University of Cambridge, Cambridge CB2 3EH, UK; Wellcome Sanger Institute, Wellcome Genome Campus, Cambridge CB10 1SA, UK
| | - Benjamin D Simons
- Department of Applied Mathematics and Theoretical Physics, Centre for Mathematical Sciences, University of Cambridge, Cambridge, CB3 0WA, UK; Wellcome Trust, Cancer Research UK Gurdon Institute, University of Cambridge, Cambridge, CB2 1QN, UK; Wellcome Trust-Medical Research Council Cambridge Stem Cell Institute, Jeffrey Cheah Biomedical Centre, University of Cambridge, Cambridge, CB2 0AW, UK.
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11
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An atypical RNA quadruplex marks RNAs as vectors for gene silencing. Nat Struct Mol Biol 2022; 29:1113-1121. [PMID: 36352138 PMCID: PMC10092862 DOI: 10.1038/s41594-022-00854-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Accepted: 09/28/2022] [Indexed: 11/11/2022]
Abstract
The addition of poly(UG) ('pUG') repeats to 3' termini of mRNAs drives gene silencing and transgenerational epigenetic inheritance in the metazoan Caenorhabditis elegans. pUG tails promote silencing by recruiting an RNA-dependent RNA polymerase (RdRP) that synthesizes small interfering RNAs. Here we show that active pUG tails require a minimum of 11.5 repeats and adopt a quadruplex (G4) structure we term the pUG fold. The pUG fold differs from known G4s in that it has a left-handed backbone similar to Z-RNA, no consecutive guanosines in its sequence, and three G quartets and one U quartet stacked non-sequentially. The compact pUG fold binds six potassium ions and brings the RNA ends into close proximity. The biological importance of the pUG fold is emphasized by our observations that porphyrin molecules bind to the pUG fold and inhibit both gene silencing and binding of RdRP. Moreover, specific 7-deaza substitutions that disrupt the pUG fold neither bind RdRP nor induce RNA silencing. These data define the pUG fold as a previously unrecognized RNA structural motif that drives gene silencing. The pUG fold can also form internally within larger RNA molecules. Approximately 20,000 pUG-fold sequences are found in noncoding regions of human RNAs, suggesting that the fold probably has biological roles beyond gene silencing.
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12
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Dai S, Tang X, Li L, Ishidate T, Ozturk AR, Chen H, Dude AL, Yan YH, Dong MQ, Shen EZ, Mello CC. A family of C. elegans VASA homologs control Argonaute pathway specificity and promote transgenerational silencing. Cell Rep 2022; 40:111265. [PMID: 36070689 PMCID: PMC9887883 DOI: 10.1016/j.celrep.2022.111265] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Revised: 06/01/2022] [Accepted: 08/04/2022] [Indexed: 02/02/2023] Open
Abstract
Germline Argonautes direct transcriptome surveillance within perinuclear membraneless organelles called nuage. In C. elegans, a family of Vasa-related Germ Line Helicase (GLH) proteins localize in and promote the formation of nuage. Previous studies have implicated GLH proteins in inherited silencing, but direct roles in small-RNA production, Argonaute binding, or mRNA targeting have not been identified. Here we show that GLH proteins compete with each other to control Argonaute pathway specificity, bind directly to Argonaute target mRNAs, and promote the amplification of small RNAs required for transgenerational inheritance. We show that the ATPase cycle of GLH-1 regulates direct binding to the Argonaute WAGO-1, which engages amplified small RNAs. Our findings support a dynamic and direct role for GLH proteins in inherited silencing beyond their role as structural components of nuage.
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Affiliation(s)
- Siyuan Dai
- RNA Therapeutic Institute, UMass Chan Medical School, Worcester, MA 01605, USA; Morningside Graduate School of Biomedical Sciences, UMass Chan Medical School, Worcester, MA 01605, USA
| | - Xiaoyin Tang
- Key Laboratory of Growth Regulation and Translational Research of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, China
| | - Lili Li
- Key Laboratory of Growth Regulation and Translational Research of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, China
| | - Takao Ishidate
- RNA Therapeutic Institute, UMass Chan Medical School, Worcester, MA 01605, USA
| | - Ahmet R Ozturk
- RNA Therapeutic Institute, UMass Chan Medical School, Worcester, MA 01605, USA
| | - Hao Chen
- Program in Bioinformatics and Integrative Biology, UMass Chan Medical School, Worcester, MA 01605, USA; Bioinformatics Program, Boston University, Boston, MA 02215, USA
| | - Altair L Dude
- RNA Therapeutic Institute, UMass Chan Medical School, Worcester, MA 01605, USA
| | - Yong-Hong Yan
- National Institute of Biological Sciences, Beijing 102206, China
| | - Meng-Qiu Dong
- National Institute of Biological Sciences, Beijing 102206, China
| | - En-Zhi Shen
- Key Laboratory of Growth Regulation and Translational Research of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, China; Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, China.
| | - Craig C Mello
- RNA Therapeutic Institute, UMass Chan Medical School, Worcester, MA 01605, USA; Howard Hughes Medical Institute, Worcester, MA 01605, USA.
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13
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Ouyang JPT, Zhang WL, Seydoux G. The conserved helicase ZNFX-1 memorializes silenced RNAs in perinuclear condensates. Nat Cell Biol 2022; 24:1129-1140. [PMID: 35739318 PMCID: PMC9276528 DOI: 10.1038/s41556-022-00940-w] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Accepted: 05/11/2022] [Indexed: 01/23/2023]
Abstract
RNA-mediated interference (RNAi) is a conserved mechanism that uses small RNAs (sRNAs) to silence gene expression. In the Caenorhabditis elegans germline, transcripts targeted by sRNAs are used as templates for sRNA amplification to propagate silencing into the next generation. Here we show that RNAi leads to heritable changes in the distribution of nascent and mature transcripts that correlate with two parallel sRNA amplification loops. The first loop, dependent on the nuclear Argonaute HRDE-1, targets nascent transcripts and reduces but does not eliminate productive transcription at the locus. The second loop, dependent on the conserved helicase ZNFX-1, targets mature transcripts and concentrates them in perinuclear condensates. ZNFX-1 interacts with sRNA-targeted transcripts that have acquired poly(UG) tails and is required to sustain pUGylation and robust sRNA amplification in the inheriting generation. By maintaining a pool of transcripts for amplification, ZNFX-1 prevents premature extinction of the RNAi response and extends silencing into the next generation.
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Affiliation(s)
- John Paul Tsu Ouyang
- HHMI and Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Wenyan Lucy Zhang
- HHMI and Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Geraldine Seydoux
- HHMI and Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
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14
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Bush NM, Hunter CP. Don't put all your epigenetic eggs in one basket. Nat Cell Biol 2022; 24:1016-1018. [PMID: 35773433 DOI: 10.1038/s41556-022-00948-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Nicole M Bush
- The Biological Laboratories, Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, USA
| | - Craig P Hunter
- The Biological Laboratories, Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, USA.
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15
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Quarato P, Singh M, Bourdon L, Cecere G. Inheritance and maintenance of small RNA-mediated epigenetic effects. Bioessays 2022; 44:e2100284. [PMID: 35338497 DOI: 10.1002/bies.202100284] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 02/04/2022] [Accepted: 03/15/2022] [Indexed: 11/08/2022]
Abstract
Heritable traits are predominantly encoded within genomic DNA, but it is now appreciated that epigenetic information is also inherited through DNA methylation, histone modifications, and small RNAs. Several examples of transgenerational epigenetic inheritance of traits have been documented in plants and animals. These include even the inheritance of traits acquired through the soma during the life of an organism, implicating the transfer of epigenetic information via the germline to the next generation. Small RNAs appear to play a significant role in carrying epigenetic information across generations. This review focuses on how epigenetic information in the form of small RNAs is transmitted from the germline to the embryos through the gametes. We also consider how inherited epigenetic information is maintained across generations in a small RNA-dependent and independent manner. Finally, we discuss how epigenetic traits acquired from the soma can be inherited through small RNAs.
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Affiliation(s)
- Piergiuseppe Quarato
- Department of Developmental and Stem Cell Biology, Institut Pasteur, Université de Paris, CNRS UMR3738, Mechanisms of Epigenetic Inheritance, Paris, France
| | - Meetali Singh
- Department of Developmental and Stem Cell Biology, Institut Pasteur, Université de Paris, CNRS UMR3738, Mechanisms of Epigenetic Inheritance, Paris, France
| | - Loan Bourdon
- Department of Developmental and Stem Cell Biology, Institut Pasteur, Université de Paris, CNRS UMR3738, Mechanisms of Epigenetic Inheritance, Paris, France
| | - Germano Cecere
- Department of Developmental and Stem Cell Biology, Institut Pasteur, Université de Paris, CNRS UMR3738, Mechanisms of Epigenetic Inheritance, Paris, France
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16
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Phillips CM, Updike DL. Germ granules and gene regulation in the Caenorhabditis elegans germline. Genetics 2022; 220:6541922. [PMID: 35239965 PMCID: PMC8893257 DOI: 10.1093/genetics/iyab195] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Accepted: 10/10/2021] [Indexed: 01/27/2023] Open
Abstract
The transparency of Caenorhabditis elegans provides a unique window to observe and study the function of germ granules. Germ granules are specialized ribonucleoprotein (RNP) assemblies specific to the germline cytoplasm, and they are largely conserved across Metazoa. Within the germline cytoplasm, they are positioned to regulate mRNA abundance, translation, small RNA production, and cytoplasmic inheritance to help specify and maintain germline identity across generations. Here we provide an overview of germ granules and focus on the significance of more recent observations that describe how they further demix into sub-granules, each with unique compositions and functions.
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Affiliation(s)
- Carolyn M Phillips
- Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA,Corresponding author: (C.M.P.); (D.L.U.)
| | - Dustin L Updike
- The Mount Desert Island Biological Laboratory, Bar Harbor, ME 04672, USA,Corresponding author: (C.M.P.); (D.L.U.)
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17
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Reprogramming the piRNA pathway for multiplexed and transgenerational gene silencing in C. elegans. Nat Methods 2022; 19:187-194. [PMID: 35115715 PMCID: PMC9798472 DOI: 10.1038/s41592-021-01369-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 12/07/2021] [Indexed: 01/01/2023]
Abstract
Single-guide RNAs can target exogenous CRISPR-Cas proteins to unique DNA locations, enabling genetic tools that are efficient, specific and scalable. Here we show that short synthetic guide Piwi-interacting RNAs (piRNAs) (21-nucleotide sg-piRNAs) expressed from extrachromosomal transgenes can, analogously, reprogram the endogenous piRNA pathway for gene-specific silencing in the hermaphrodite germline, sperm and embryos of Caenorhabditis elegans. piRNA-mediated interference ('piRNAi') is more efficient than RNAi and can be multiplexed, and auxin-mediated degradation of the piRNA-specific Argonaute PRG-1 allows conditional gene silencing. Target-specific silencing results in decreased messenger RNA levels, amplification of secondary small interfering RNAs and repressive chromatin modifications. Short (300 base pairs) piRNAi transgenes amplified from arrayed oligonucleotide pools also induce silencing, potentially making piRNAi highly scalable. We show that piRNAi can induce transgenerational epigenetic silencing of two endogenous genes (him-5 and him-8). Silencing is inherited for four to six generations after target-specific sg-piRNAs are lost, whereas depleting PRG-1 leads to essentially permanent epigenetic silencing.
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18
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Cornes E, Bourdon L, Singh M, Mueller F, Quarato P, Wernersson E, Bienko M, Li B, Cecere G. piRNAs initiate transcriptional silencing of spermatogenic genes during C. elegans germline development. Dev Cell 2022; 57:180-196.e7. [PMID: 34921763 PMCID: PMC8796119 DOI: 10.1016/j.devcel.2021.11.025] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 11/02/2021] [Accepted: 11/26/2021] [Indexed: 12/22/2022]
Abstract
Eukaryotic genomes harbor invading transposable elements that are silenced by PIWI-interacting RNAs (piRNAs) to maintain genome integrity in animal germ cells. However, whether piRNAs also regulate endogenous gene expression programs remains unclear. Here, we show that C. elegans piRNAs trigger the transcriptional silencing of hundreds of spermatogenic genes during spermatogenesis, promoting sperm differentiation and function. This silencing signal requires piRNA-dependent small RNA biogenesis and loading into downstream nuclear effectors, which correlates with the dynamic reorganization of two distinct perinuclear biomolecular condensates present in germ cells. In addition, the silencing capacity of piRNAs is temporally counteracted by the Argonaute CSR-1, which targets and licenses spermatogenic gene transcription. The spatial and temporal overlap between these opposing small RNA pathways contributes to setting up the timing of the spermatogenic differentiation program. Thus, our work identifies a prominent role for piRNAs as direct regulators of endogenous transcriptional programs during germline development and gamete differentiation.
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Affiliation(s)
- Eric Cornes
- Mechanisms of Epigenetic Inheritance, Department of Developmental and Stem Cell Biology, Institut Pasteur, UMR 3738, CNRS, Paris 75015, France
| | - Loan Bourdon
- Mechanisms of Epigenetic Inheritance, Department of Developmental and Stem Cell Biology, Institut Pasteur, UMR 3738, CNRS, Paris 75015, France
| | - Meetali Singh
- Mechanisms of Epigenetic Inheritance, Department of Developmental and Stem Cell Biology, Institut Pasteur, UMR 3738, CNRS, Paris 75015, France
| | - Florian Mueller
- Imaging and Modeling Unit, Institut Pasteur, UMR 3691 CNRS, C3BI USR 3756 IP CNRS, Paris, France
| | - Piergiuseppe Quarato
- Mechanisms of Epigenetic Inheritance, Department of Developmental and Stem Cell Biology, Institut Pasteur, UMR 3738, CNRS, Paris 75015, France
| | - Erik Wernersson
- Division of Genome Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm 17165, Sweden; Science for Life Laboratory, Tomtebodavägen 23A, Stockholm 17165, Sweden
| | - Magda Bienko
- Division of Genome Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm 17165, Sweden; Science for Life Laboratory, Tomtebodavägen 23A, Stockholm 17165, Sweden
| | - Blaise Li
- Mechanisms of Epigenetic Inheritance, Department of Developmental and Stem Cell Biology, Institut Pasteur, UMR 3738, CNRS, Paris 75015, France; Bioinformatics and Biostatistics Hub, Department of Computational Biology, Institut Pasteur, USR 3756, CNRS, Paris 75015, France
| | - Germano Cecere
- Mechanisms of Epigenetic Inheritance, Department of Developmental and Stem Cell Biology, Institut Pasteur, UMR 3738, CNRS, Paris 75015, France.
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19
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Pastore B, Hertz HL, Tang W. Comparative analysis of piRNA sequences, targets and functions in nematodes. RNA Biol 2022; 19:1276-1292. [PMID: 36412988 PMCID: PMC9683057 DOI: 10.1080/15476286.2022.2149170] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Piwi proteins and Piwi-interacting RNAs (piRNAs) are best known for their roles in suppressing transposons and promoting fertility. Yet piRNA biogenesis and its mechanisms of action differ widely between distantly related species. To better understand the evolution of piRNAs, we characterized the piRNA pathway in C. briggsae, a sibling species of the model organism C. elegans. Our analyses define 25,883 piRNA producing-loci in C. briggsae. piRNA sequences in C. briggsae are extremely divergent from their counterparts in C. elegans, yet both species adopt similar genomic organization that drive piRNA expression. By examining production of Piwi-mediated secondary small RNAs, we identified a set of protein-coding genes that are evolutionarily conserved piRNA targets. In contrast to C. elegans, small RNAs targeting ribosomal RNAs or histone transcripts are not hyper-accumulated in C. briggsae Piwi mutants. Instead, we found that transcripts with few introns are prone to small RNA overamplification. Together our work highlights evolutionary conservation and divergence of the nematode piRNA pathway and provides insights into its role in endogenous gene regulation.
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Affiliation(s)
- Benjamin Pastore
- Department of Biological Chemistry and Pharmacology, The Ohio State University,Department of Biological Chemistry and Pharmacology, Ohio State University, Columbus, OH, USA,Center for RNA Biology, Ohio State University, Columbus, OH, USA
| | - Hannah L. Hertz
- Department of Biological Chemistry and Pharmacology, The Ohio State University,Department of Biological Chemistry and Pharmacology, Ohio State University, Columbus, OH, USA
| | - Wen Tang
- Department of Biological Chemistry and Pharmacology, The Ohio State University,Department of Biological Chemistry and Pharmacology, Ohio State University, Columbus, OH, USA,CONTACT Wen Tang Department of Biological Chemistry and Pharmacology, The Ohio State University, Columbus, OH, USA
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20
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Ouyang JPT, Seydoux G. Nuage condensates: accelerators or circuit breakers for sRNA silencing pathways? RNA (NEW YORK, N.Y.) 2022; 28:58-66. [PMID: 34772788 PMCID: PMC8675287 DOI: 10.1261/rna.079003.121] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Nuage are RNA-rich condensates that assemble around the nuclei of developing germ cells. Many proteins required for the biogenesis and function of silencing small RNAs (sRNAs) enrich in nuage, and it is often assumed that nuage is the cellular site where sRNAs are synthesized and encounter target transcripts for silencing. Using C. elegans as a model, we examine the complex multicondensate architecture of nuage and review evidence for compartmentalization of silencing pathways. We consider the possibility that nuage condensates balance the activity of competing sRNA pathways and serve to limit, rather than enhance, sRNA amplification to protect transcripts from dangerous runaway silencing.
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Affiliation(s)
- John Paul Tsu Ouyang
- HHMI and Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
| | - Geraldine Seydoux
- HHMI and Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
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21
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Montgomery BE, Vijayasarathy T, Marks TN, Cialek CA, Reed KJ, Montgomery TA. Dual roles for piRNAs in promoting and preventing gene silencing in C. elegans. Cell Rep 2021; 37:110101. [PMID: 34879267 PMCID: PMC8730336 DOI: 10.1016/j.celrep.2021.110101] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 10/25/2021] [Accepted: 11/15/2021] [Indexed: 12/30/2022] Open
Abstract
Piwi-interacting RNAs (piRNAs) regulate many biological processes through mechanisms that are not fully understood. In Caenorhabditis elegans, piRNAs intersect the endogenous RNA interference (RNAi) pathway, involving a distinct class of small RNAs called 22G-RNAs, to regulate gene expression in the germline. In the absence of piRNAs, 22G-RNA production from many genes is reduced, pointing to a role for piRNAs in facilitating endogenous RNAi. Here, however, we show that many genes gain, rather than lose, 22G-RNAs in the absence of piRNAs, which is in some instances coincident with RNA silencing. Aberrant 22G-RNA production is somewhat stochastic but once established can occur within a population for at least 50 generations. Thus, piRNAs both promote and suppress 22G-RNA production and gene silencing. rRNAs and histones are hypersusceptible to aberrant silencing, but we do not find evidence that their misexpression is the primary cause of the transgenerational sterility observed in piRNA-defective mutants. Montgomery et al. show that piRNAs both promote and suppress siRNA production and RNA silencing in C. elegans. Gain or loss of siRNAs occurs somewhat stochastically in piRNA-defective mutants but once established, it occurs across numerous generations.
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Affiliation(s)
- Brooke E Montgomery
- Department of Biology, Colorado State University, Fort Collins, CO 80523, USA
| | - Tarah Vijayasarathy
- Department of Biology, Colorado State University, Fort Collins, CO 80523, USA
| | - Taylor N Marks
- Department of Biology, Colorado State University, Fort Collins, CO 80523, USA
| | - Charlotte A Cialek
- Department of Biology, Colorado State University, Fort Collins, CO 80523, USA; Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, Colorado 80523, USA
| | - Kailee J Reed
- Department of Biology, Colorado State University, Fort Collins, CO 80523, USA; Cell and Molecular Biology Program, Colorado State University, Fort Collins, CO 80523, USA
| | - Taiowa A Montgomery
- Department of Biology, Colorado State University, Fort Collins, CO 80523, USA; Cell and Molecular Biology Program, Colorado State University, Fort Collins, CO 80523, USA.
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22
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Abstract
DNA is central to the propagation and evolution of most living organisms due to the essential process of its self-replication. Yet it also encodes factors that permit epigenetic (not included in DNA sequence) flow of information from parents to their offspring and beyond. The known mechanisms of epigenetic inheritance include chemical modifications of DNA and chromatin, as well as regulatory RNAs. All these factors can modulate gene expression programs in the ensuing generations. The nematode Caenorhabditis elegans is recognized as a pioneer organism in transgenerational epigenetic inheritance research. Recent advances in C. elegans epigenetics include the discoveries of control mechanisms that limit the duration of RNA-based epigenetic inheritance, periodic DNA motifs that counteract epigenetic silencing establishment, new mechanistic insights into epigenetic inheritance carried by sperm, and the tantalizing examples of inheritance of sensory experiences. This review aims to highlight new findings in epigenetics research in C. elegans with the main focus on transgenerational epigenetic phenomena dependent on small RNAs.
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Affiliation(s)
- Alla Grishok
- Department of Biochemistry, BU Genome Science Institute, Boston University School of Medicine, 72 E. Concord St. K422, Boston, MA 02118, USA
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23
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Cecere G. Small RNAs in epigenetic inheritance: from mechanisms to trait transmission. FEBS Lett 2021; 595:2953-2977. [PMID: 34671979 PMCID: PMC9298081 DOI: 10.1002/1873-3468.14210] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 10/08/2021] [Accepted: 10/18/2021] [Indexed: 01/02/2023]
Abstract
Inherited information is transmitted to progeny primarily by the genome through the gametes. However, in recent years, epigenetic inheritance has been demonstrated in several organisms, including animals. Although it is clear that certain post‐translational histone modifications, DNA methylation, and noncoding RNAs regulate epigenetic inheritance, the molecular mechanisms responsible for epigenetic inheritance are incompletely understood. This review focuses on the role of small RNAs in transmitting epigenetic information across generations in animals. Examples of documented cases of transgenerational epigenetic inheritance are discussed, from the silencing of transgenes to the inheritance of complex traits, such as fertility, stress responses, infections, and behavior. Experimental evidence supporting the idea that small RNAs are epigenetic molecules capable of transmitting traits across generations is highlighted, focusing on the mechanisms by which small RNAs achieve such a function. Just as the role of small RNAs in epigenetic processes is redefining the concept of inheritance, so too our understanding of the molecular pathways and mechanisms that govern epigenetic inheritance in animals is radically changing.
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Affiliation(s)
- Germano Cecere
- Mechanisms of Epigenetic Inheritance, Department of Developmental and Stem Cell Biology, Institut Pasteur, UMR3738, CNRS, Paris, France
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