1
|
Li Y, Wang K, Liu W, Zhang Y. The potential emerging role of piRNA/PIWI complex in virus infection. Virus Genes 2024; 60:333-346. [PMID: 38833149 DOI: 10.1007/s11262-024-02078-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2024] [Accepted: 05/18/2024] [Indexed: 06/06/2024]
Abstract
P-element-induced wimpy testis-interacting RNAs (piRNAs), a class of small noncoding RNAs with about 24-32 nucleotides, often interact with PIWI proteins to form a piRNA/PIWI complex that could influence spermiogenesis, transposon silencing, epigenetic regulation, etc. PIWI proteins have a highly conserved function in a variety of species and are usually expressed in germ cells. However, increasing evidence has revealed the important role of the piRNA/PIWI complex in the occurrence and prognosis of various human diseases and suggests its potential application in the diagnosis and treatment of related diseases, becoming a prominent marker for these human diseases. Recent studies have confirmed that piRNA/PIWI complexes or piRNAs are abnormally expressed in some viral infections, effecting disease progression and viral replication. In this study, we reviewed the association between the piRNA/PIWI complex and several human disease-associated viruses, including human papillomavirus, human immunodeficiency virus, human rhinovirus, severe acute respiratory syndrome coronavirus 2, respiratory syncytial virus, and herpes simplex virus type 1.
Collapse
Affiliation(s)
- Yanyan Li
- Department of Clinical Laboratory, Zibo Central Hospital, 54 Gongqingtuan Road, Zibo, 255036, China
| | - Kai Wang
- Department of Clinical Laboratory, Zibo Central Hospital, 54 Gongqingtuan Road, Zibo, 255036, China
| | - Wen Liu
- Department of Pathogenic Biology, School of Basic Medicine, Qingdao University, Qingdao, 266071, China.
| | - Yan Zhang
- Department of Clinical Laboratory, Zibo Central Hospital, 54 Gongqingtuan Road, Zibo, 255036, China.
- Department of Pathogenic Biology, School of Basic Medicine, Qingdao University, Qingdao, 266071, China.
| |
Collapse
|
2
|
Lau NC, Macias VM. Transposon and Transgene Tribulations in Mosquitoes: A Perspective of piRNA Proportions. DNA 2024; 4:104-128. [PMID: 39076684 PMCID: PMC11286205 DOI: 10.3390/dna4020006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 07/31/2024]
Abstract
Mosquitoes, like Drosophila, are dipterans, the order of "true flies" characterized by a single set of two wings. Drosophila are prime model organisms for biomedical research, while mosquito researchers struggle to establish robust molecular biology in these that are arguably the most dangerous vectors of human pathogens. Both insects utilize the RNA interference (RNAi) pathway to generate small RNAs to silence transposons and viruses, yet details are emerging that several RNAi features are unique to each insect family, such as how culicine mosquitoes have evolved extreme genomic feature differences connected to their unique RNAi features. A major technical difference in the molecular genetic studies of these insects is that generating stable transgenic animals are routine in Drosophila but still variable in stability in mosquitoes, despite genomic DNA-editing advances. By comparing and contrasting the differences in the RNAi pathways of Drosophila and mosquitoes, in this review we propose a hypothesis that transgene DNAs are possibly more intensely targeted by mosquito RNAi pathways and chromatin regulatory pathways than in Drosophila. We review the latest findings on mosquito RNAi pathways, which are still much less well understood than in Drosophila, and we speculate that deeper study into how mosquitoes modulate transposons and viruses with Piwi-interacting RNAs (piRNAs) will yield clues to improving transgene DNA expression stability in transgenic mosquitoes.
Collapse
Affiliation(s)
- Nelson C. Lau
- Department of Biochemistry and Cell Biology, Boston University Chobanian and Avedisian School of Medicine, Boston, MA 02118, USA
- Genome Science Institute and National Emerging Infectious Disease Laboratory, Boston University Chobanian and Avedisian School of Medicine, Boston, MA 02118, USA
| | - Vanessa M. Macias
- Department of Biology, University of North Texas, Denton, TX 76205, USA
- Advanced Environmental Research Institute, University of North Texas, Denton, TX 76205, USA
| |
Collapse
|
3
|
Ho S, Theurkauf W, Rice N. piRNA-Guided Transposon Silencing and Response to Stress in Drosophila Germline. Viruses 2024; 16:714. [PMID: 38793595 PMCID: PMC11125864 DOI: 10.3390/v16050714] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Revised: 04/23/2024] [Accepted: 04/27/2024] [Indexed: 05/26/2024] Open
Abstract
Transposons are integral genome constituents that can be domesticated for host functions, but they also represent a significant threat to genome stability. Transposon silencing is especially critical in the germline, which is dedicated to transmitting inherited genetic material. The small Piwi-interacting RNAs (piRNAs) have a deeply conserved function in transposon silencing in the germline. piRNA biogenesis and function are particularly well understood in Drosophila melanogaster, but some fundamental mechanisms remain elusive and there is growing evidence that the pathway is regulated in response to genotoxic and environmental stress. Here, we review transposon regulation by piRNAs and the piRNA pathway regulation in response to stress, focusing on the Drosophila female germline.
Collapse
Affiliation(s)
- Samantha Ho
- Program in Molecular Medicine, University Campus, University of Massachusetts Chan Medical School, Worcester, MA 01655, USA;
| | | | - Nicholas Rice
- Program in Molecular Medicine, University Campus, University of Massachusetts Chan Medical School, Worcester, MA 01655, USA;
| |
Collapse
|
4
|
Balan T, Lerner LK, Holoch D, Duharcourt S. Small-RNA-guided histone modifications and somatic genome elimination in ciliates. WILEY INTERDISCIPLINARY REVIEWS. RNA 2024; 15:e1848. [PMID: 38605483 DOI: 10.1002/wrna.1848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Revised: 03/22/2024] [Accepted: 03/22/2024] [Indexed: 04/13/2024]
Abstract
Transposable elements and other repeats are repressed by small-RNA-guided histone modifications in fungi, plants and animals. The specificity of silencing is achieved through base-pairing of small RNAs corresponding to the these genomic loci to nascent noncoding RNAs, which allows the recruitment of histone methyltransferases that methylate histone H3 on lysine 9. Self-reinforcing feedback loops enhance small RNA production and ensure robust and heritable repression. In the unicellular ciliate Paramecium tetraurelia, small-RNA-guided histone modifications lead to the elimination of transposable elements and their remnants, a definitive form of repression. In this organism, germline and somatic functions are separated within two types of nuclei with different genomes. At each sexual cycle, development of the somatic genome is accompanied by the reproducible removal of approximately a third of the germline genome. Instead of recruiting a H3K9 methyltransferase, small RNAs corresponding to eliminated sequences tether Polycomb Repressive Complex 2, which in ciliates has the unique property of catalyzing both lysine 9 and lysine 27 trimethylation of histone H3. These histone modifications that are crucial for the elimination of transposable elements are thought to guide the endonuclease complex, which triggers double-strand breaks at these specific genomic loci. The comparison between ciliates and other eukaryotes underscores the importance of investigating small-RNAs-directed chromatin silencing in a diverse range of organisms. This article is categorized under: Regulatory RNAs/RNAi/Riboswitches > RNAi: Mechanisms of Action.
Collapse
Affiliation(s)
- Thomas Balan
- Université Paris Cité, CNRS, Institut Jacques Monod, Paris, France
| | | | - Daniel Holoch
- Université Paris Cité, CNRS, Institut Jacques Monod, Paris, France
- Institut Curie, INSERM U934/CNRS UMR 3215, Paris Sciences et Lettres Research University, Sorbonne University, Paris, France
| | | |
Collapse
|
5
|
Koryakov DE. Diversity and functional specialization of H3K9-specific histone methyltransferases. Bioessays 2024; 46:e2300163. [PMID: 38058121 DOI: 10.1002/bies.202300163] [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: 08/29/2023] [Revised: 11/16/2023] [Accepted: 11/20/2023] [Indexed: 12/08/2023]
Abstract
Histone modifications play a critical role in the control over activities of the eukaryotic genome; among these chemical alterations, the methylation of lysine K9 in histone H3 (H3K9) is one of the most extensively studied. The number of enzymes capable of methylating H3K9 varies greatly across different organisms: in fission yeast, only one such methyltransferase is present, whereas in mammals, 10 are known. If there are several such enzymes, each of them must have some specific function, and they can interact with one another. Thus arises a complex system of interchangeability, "division of labor," and contacts with each other and with diverse proteins. Histone methyltransferases specialize in the number of methyl groups that they attach and have different intracellular localizations as well as different distributions on chromosomes. Each also shows distinct binding to different types of sequences and has a specific set of nonhistone substrates.
Collapse
Affiliation(s)
- Dmitry E Koryakov
- Lab of Molecular Cytogenetics, Institute of Molecular and Cellular Biology, Novosibirsk, Russia
| |
Collapse
|
6
|
Romanov SE, Shloma VV, Maksimov DA, Koryakov DE. SetDB1 and Su(var)3-9 are essential for late stages of larval development of Drosophila melanogaster. Chromosome Res 2023; 31:35. [PMID: 38099968 DOI: 10.1007/s10577-023-09743-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 10/25/2023] [Accepted: 11/02/2023] [Indexed: 12/18/2023]
Abstract
Methylation of H3K9 histone residue is a marker of gene silencing in eukaryotes. Three enzymes responsible for adding this modification - G9a, SetDB1/Egg, and Su(var)3-9 - are known in Drosophila. To understand how simultaneous mutations of SetDB1 and Su(var)3-9 may affect the fly development, appropriate combinations were obtained. Double mutants egg; Su(var)3-9 displayed pronounced embryonic lethality, slower larval growth and died before or during metamorphosis. Analysis of transcription in larval salivary glands and wing imaginal disks indicated that the effect of double mutation is tissue-specific. In salivary gland chromosomes, affected genes display low H3K9me2 enrichment and are rarely bound by SetDB1 or Su(var)3-9. We suppose that each of these enzymes directly or indirectly controls its own set of gene targets in different organs, and double mutation results in an imbalanced developmental program. This also indicates that SetDB1 and Su(var)3-9 may affect transcription via H3K9-independent mechanisms. Unexpectedly, in double and triple mutants, amount of di- and tri-methylated H3K9 is drastically reduced, but not completely absent. We hypothesize that this residual methylation implies the existence of additional H3K9-specific methyltransferase in Drosophila.
Collapse
Affiliation(s)
- Stanislav E Romanov
- Institute of Molecular and Cellular Biology SB RAS, Novosibirsk, 630090, Russia
| | - Viktor V Shloma
- Institute of Molecular and Cellular Biology SB RAS, Novosibirsk, 630090, Russia
| | - Daniil A Maksimov
- Institute of Molecular and Cellular Biology SB RAS, Novosibirsk, 630090, Russia
| | - Dmitry E Koryakov
- Institute of Molecular and Cellular Biology SB RAS, Novosibirsk, 630090, Russia.
| |
Collapse
|
7
|
Melnikova L, Golovnin A. Multiple Roles of dXNP and dADD1- Drosophila Orthologs of ATRX Chromatin Remodeler. Int J Mol Sci 2023; 24:16486. [PMID: 38003676 PMCID: PMC10671109 DOI: 10.3390/ijms242216486] [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: 10/09/2023] [Revised: 11/11/2023] [Accepted: 11/16/2023] [Indexed: 11/26/2023] Open
Abstract
The Drosophila melanogaster dADD1 and dXNP proteins are orthologues of the ADD and SNF2 domains of the vertebrate ATRX (Alpha-Thalassemia with mental Retardation X-related) protein. ATRX plays a role in general molecular processes, such as regulating chromatin status and gene expression, while dADD1 and dXNP have similar functions in the Drosophila genome. Both ATRX and dADD1/dXNP interact with various protein partners and participate in various regulatory complexes. Disruption of ATRX expression in humans leads to the development of α-thalassemia and cancer, especially glioma. However, the mechanisms that allow ATRX to regulate various cellular processes are poorly understood. Studying the functioning of dADD1/dXNP in the Drosophila model may contribute to understanding the mechanisms underlying the multifunctional action of ATRX and its connection with various cellular processes. This review provides a brief overview of the currently available information in mammals and Drosophila regarding the roles of ATRX, dXNP, and dADD1. It discusses possible mechanisms of action of complexes involving these proteins.
Collapse
Affiliation(s)
- Larisa Melnikova
- Department of Drosophila Molecular Genetics, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov St., 119334 Moscow, Russia
| | - Anton Golovnin
- Department of Drosophila Molecular Genetics, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov St., 119334 Moscow, Russia
| |
Collapse
|
8
|
Luo Y, He P, Kanrar N, Fejes Toth K, Aravin AA. Maternally inherited siRNAs initiate piRNA cluster formation. Mol Cell 2023; 83:3835-3851.e7. [PMID: 37875112 PMCID: PMC10846595 DOI: 10.1016/j.molcel.2023.09.033] [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: 02/14/2022] [Revised: 05/08/2023] [Accepted: 09/26/2023] [Indexed: 10/26/2023]
Abstract
PIWI-interacting RNAs (piRNAs) guide transposable element repression in animal germ lines. In Drosophila, piRNAs are produced from heterochromatic loci, called piRNA clusters, which act as information repositories about genome invaders. piRNA generation by dual-strand clusters depends on the chromatin-bound Rhino-Deadlock-Cutoff (RDC) complex, which is deposited on clusters guided by piRNAs, forming a positive feedback loop in which piRNAs promote their own biogenesis. However, how piRNA clusters are formed before cognate piRNAs are present remains unknown. Here, we report spontaneous de novo piRNA cluster formation from repetitive transgenic sequences. Cluster formation occurs over several generations and requires continuous trans-generational maternal transmission of small RNAs. We discovered that maternally supplied small interfering RNAs (siRNAs) trigger de novo cluster activation in progeny. In contrast, siRNAs are dispensable for cluster function after its establishment. These results reveal an unexpected interplay between the siRNA and piRNA pathways and suggest a mechanism for de novo piRNA cluster formation triggered by siRNAs.
Collapse
Affiliation(s)
- Yicheng Luo
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Peng He
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Nivedita Kanrar
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Katalin Fejes Toth
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Alexei A Aravin
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA.
| |
Collapse
|
9
|
Kalmykova AI, Sokolova OA. Retrotransposons and Telomeres. BIOCHEMISTRY. BIOKHIMIIA 2023; 88:1739-1753. [PMID: 38105195 DOI: 10.1134/s0006297923110068] [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: 06/19/2023] [Revised: 07/24/2023] [Accepted: 08/12/2023] [Indexed: 12/19/2023]
Abstract
Transposable elements (TEs) comprise a significant part of eukaryotic genomes being a major source of genome instability and mutagenesis. Cellular defense systems suppress the TE expansion at all stages of their life cycle. Piwi proteins and Piwi-interacting RNAs (piRNAs) are key elements of the anti-transposon defense system, which control TE activity in metazoan gonads preventing inheritable transpositions and developmental defects. In this review, we discuss various regulatory mechanisms by which small RNAs combat TE activity. However, active transposons persist, suggesting these powerful anti-transposon defense mechanisms have a limited capacity. A growing body of evidence suggests that increased TE activity coincides with genome reprogramming and telomere lengthening in different species. In the Drosophila fruit fly, whose telomeres consist only of retrotransposons, a piRNA-mediated mechanism is required for telomere maintenance and their length control. Therefore, the efficacy of protective mechanisms must be finely balanced in order not only to suppress the activity of transposons, but also to maintain the proper length and stability of telomeres. Structural and functional relationship between the telomere homeostasis and LINE1 retrotransposon in human cells indicates a close link between selfish TEs and the vital structure of the genome, telomere. This relationship, which permits the retention of active TEs in the genome, is reportedly a legacy of the retrotransposon origin of telomeres. The maintenance of telomeres and the execution of other crucial roles that TEs acquired during the process of their domestication in the genome serve as a type of payment for such a "service."
Collapse
Affiliation(s)
- Alla I Kalmykova
- Koltzov Institute of Developmental Biology, Russian Academy of Sciences, Moscow, 119334, Russia.
| | - Olesya A Sokolova
- Koltzov Institute of Developmental Biology, Russian Academy of Sciences, Moscow, 119334, Russia
| |
Collapse
|
10
|
Kotb NM, Rangan P. From stem cell to egg cell. eLife 2023; 12:e91998. [PMID: 37772961 PMCID: PMC10541171 DOI: 10.7554/elife.91998] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/30/2023] Open
Abstract
Experiments on female fruit flies reveal more about the molecular mechanisms involved as germline stem cells transition to become egg cells.
Collapse
Affiliation(s)
- Noor M Kotb
- University at Albany, State University of New YorkAlbanyUnited States
- Department of Cell, Developmental, and Regenerative Biology, Black Family Stem Cell Institute, Icahn School of Medicine at Mount SinaiNew YorkUnited States
| | - Prashanth Rangan
- Department of Cell, Developmental, and Regenerative Biology, Black Family Stem Cell Institute, Icahn School of Medicine at Mount SinaiNew YorkUnited States
| |
Collapse
|
11
|
Casier K, Autaa J, Gueguen N, Delmarre V, Marie PP, Ronsseray S, Carré C, Brasset E, Teysset L, Boivin A. The histone demethylase Kdm3 prevents auto-immune piRNAs production in Drosophila. SCIENCE ADVANCES 2023; 9:eade3872. [PMID: 37027460 PMCID: PMC10081847 DOI: 10.1126/sciadv.ade3872] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Accepted: 03/08/2023] [Indexed: 06/19/2023]
Abstract
Genome integrity of the animal germline is protected from transposable element activity by PIWI-interacting RNAs (piRNAs). While piRNA biogenesis is intensively explored, little is known about the genetical determination of piRNA clusters, the genomic sources of piRNAs. Using a bimodal epigenetic state piRNA cluster (BX2), we identified the histone demethylase Kdm3 as being able to prevent a cryptic piRNA production. In the absence of Kdm3, dozens of coding gene-containing regions become genuine germline dual-strand piRNA clusters. Eggs laid by Kdm3 mutant females show developmental defects phenocopying loss of function of genes embedded into the additional piRNA clusters, suggesting an inheritance of functional ovarian "auto-immune" piRNAs. Antagonizing piRNA cluster determination through chromatin modifications appears crucial to prevent auto-immune genic piRNAs production.
Collapse
Affiliation(s)
- Karine Casier
- Transgenerational Epigenetics and Small RNA Biology, Sorbonne Université, CNRS, Institut de Biologie Paris-Seine, Laboratoire Biologie du Développement, UMR7622, F-75005 Paris, France
| | - Julie Autaa
- Transgenerational Epigenetics and Small RNA Biology, Sorbonne Université, CNRS, Institut de Biologie Paris-Seine, Laboratoire Biologie du Développement, UMR7622, F-75005 Paris, France
| | - Nathalie Gueguen
- iGReD, CNRS, INSERM, Faculté de Médecine, Université Clermont Auvergne, 63000 Clermont-Ferrand, France
| | - Valérie Delmarre
- Transgenerational Epigenetics and Small RNA Biology, Sorbonne Université, CNRS, Institut de Biologie Paris-Seine, Laboratoire Biologie du Développement, UMR7622, F-75005 Paris, France
| | - Pauline P. Marie
- Transgenerational Epigenetics and Small RNA Biology, Sorbonne Université, CNRS, Institut de Biologie Paris-Seine, Laboratoire Biologie du Développement, UMR7622, F-75005 Paris, France
| | - Stéphane Ronsseray
- Transgenerational Epigenetics and Small RNA Biology, Sorbonne Université, CNRS, Institut de Biologie Paris-Seine, Laboratoire Biologie du Développement, UMR7622, F-75005 Paris, France
| | - Clément Carré
- Transgenerational Epigenetics and Small RNA Biology, Sorbonne Université, CNRS, Institut de Biologie Paris-Seine, Laboratoire Biologie du Développement, UMR7622, F-75005 Paris, France
| | - Emilie Brasset
- iGReD, CNRS, INSERM, Faculté de Médecine, Université Clermont Auvergne, 63000 Clermont-Ferrand, France
| | - Laure Teysset
- Transgenerational Epigenetics and Small RNA Biology, Sorbonne Université, CNRS, Institut de Biologie Paris-Seine, Laboratoire Biologie du Développement, UMR7622, F-75005 Paris, France
| | - Antoine Boivin
- Transgenerational Epigenetics and Small RNA Biology, Sorbonne Université, CNRS, Institut de Biologie Paris-Seine, Laboratoire Biologie du Développement, UMR7622, F-75005 Paris, France
| |
Collapse
|
12
|
Tang X, Liu N, Qi H, Lin H. Piwi maintains homeostasis in the Drosophila adult intestine. Stem Cell Reports 2023; 18:503-518. [PMID: 36736325 PMCID: PMC9969073 DOI: 10.1016/j.stemcr.2023.01.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 12/28/2022] [Accepted: 01/03/2023] [Indexed: 02/05/2023] Open
Abstract
PIWI genes are well known for their germline but not somatic functions. Here, we report the function of the Drosophila piwi gene in the adult gut, where intestinal stem cells (ISCs) produce enteroendocrine cells and enteroblasts that generate enterocytes. We show that piwi is expressed in ISCs and enteroblasts. Piwi deficiency reduced ISC number, compromised enteroblasts maintenance, and induced apoptosis in enterocytes, but did not affect ISC proliferation and its differentiation to enteroendocrine cells. In addition, deficiency of zygotic but not maternal piwi mildly de-silenced several retrotransposons in the adult gut. Importantly, either piwi mutations or piwi knockdown specifically in ISCs and enteroblasts shortened the Drosophila lifespan, indicating that intestinal piwi contributes to longevity. Finally, our mRNA sequencing data implied that Piwi may achieve its intestinal function by regulating diverse molecular processes involved in metabolism and oxidation-reduction reaction.
Collapse
Affiliation(s)
- Xiongzhuo Tang
- Yale Stem Cell Center, Yale School of Medicine, New Haven, CT 06519, USA; Department of Cell Biology, Yale School of Medicine, New Haven, CT 06519, USA.
| | - Na Liu
- Yale Stem Cell Center, Yale School of Medicine, New Haven, CT 06519, USA; Department of Cell Biology, Yale School of Medicine, New Haven, CT 06519, USA
| | - Hongying Qi
- Yale Stem Cell Center, Yale School of Medicine, New Haven, CT 06519, USA; Department of Cell Biology, Yale School of Medicine, New Haven, CT 06519, USA
| | - Haifan Lin
- Yale Stem Cell Center, Yale School of Medicine, New Haven, CT 06519, USA; Department of Cell Biology, Yale School of Medicine, New Haven, CT 06519, USA.
| |
Collapse
|
13
|
Measuring Transposable Element Activity in Adult Drosophila Ovaries. Methods Mol Biol 2023; 2626:309-321. [PMID: 36715912 DOI: 10.1007/978-1-0716-2970-3_16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Transposons are genetic elements that use various mechanisms of transposition to move around the genome, thus posing a risk to genomic integrity. Repression of transposable elements (TEs) involves the complex PIWI pathway and several proteins associated with heterochromatinization. All players of TE repression are indispensable for proper reproductive fitness, as loss-of-function mutations in these genes result primarily in sterility and impaired reproductive development. When investigating the function of novel genes with similar phenotypes, elevated transposon expression in reproductive tissues can be a marker for involvement in the aforementioned processes. Here, we present a protocol for investigating TE levels in adult Drosophila ovaries, from dissection to data analysis.
Collapse
|
14
|
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.
Collapse
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.
| |
Collapse
|
15
|
Miller DE, Dorador AP, Van Vaerenberghe K, Li A, Grantham EK, Cerbin S, Cummings C, Barragan M, Egidy RR, Scott AR, Hall KE, Perera A, Gilliland WD, Hawley RS, Blumenstiel JP. Off-target piRNA gene silencing in Drosophila melanogaster rescued by a transposable element insertion. PLoS Genet 2023; 19:e1010598. [PMID: 36809339 PMCID: PMC9983838 DOI: 10.1371/journal.pgen.1010598] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 03/03/2023] [Accepted: 01/04/2023] [Indexed: 02/23/2023] Open
Abstract
Transposable elements (TE) are selfish genetic elements that can cause harmful mutations. In Drosophila, it has been estimated that half of all spontaneous visible marker phenotypes are mutations caused by TE insertions. Several factors likely limit the accumulation of exponentially amplifying TEs within genomes. First, synergistic interactions between TEs that amplify their harm with increasing copy number are proposed to limit TE copy number. However, the nature of this synergy is poorly understood. Second, because of the harm posed by TEs, eukaryotes have evolved systems of small RNA-based genome defense to limit transposition. However, as in all immune systems, there is a cost of autoimmunity and small RNA-based systems that silence TEs can inadvertently silence genes flanking TE insertions. In a screen for essential meiotic genes in Drosophila melanogaster, a truncated Doc retrotransposon within a neighboring gene was found to trigger the germline silencing of ald, the Drosophila Mps1 homolog, a gene essential for proper chromosome segregation in meiosis. A subsequent screen for suppressors of this silencing identified a new insertion of a Hobo DNA transposon in the same neighboring gene. Here we describe how the original Doc insertion triggers flanking piRNA biogenesis and local gene silencing. We show that this local gene silencing occurs in cis and is dependent on deadlock, a component of the Rhino-Deadlock-Cutoff (RDC) complex, to trigger dual-strand piRNA biogenesis at TE insertions. We further show how the additional Hobo insertion leads to de-silencing by reducing flanking piRNA biogenesis triggered by the original Doc insertion. These results support a model of TE-mediated gene silencing by piRNA biogenesis in cis that depends on local determinants of transcription. This may explain complex patterns of off-target gene silencing triggered by TEs within populations and in the laboratory. It also provides a mechanism of sign epistasis among TE insertions, illuminates the complex nature of their interactions and supports a model in which off-target gene silencing shapes the evolution of the RDC complex.
Collapse
Affiliation(s)
- Danny E. Miller
- Stowers Institute for Medical Research, Kansas City, Missouri, United States of America
- Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, Kansas, United States of America
- Division of Genetic Medicine, Department of Pediatrics, University of Washington and Seattle Children’s Hospital, Seattle, Washington, United States of America
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, United States of America
| | - Ana P. Dorador
- Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, Kansas, United States of America
| | - Kelley Van Vaerenberghe
- Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, Kansas, United States of America
- Division of Biological Sciences, University of Montana, Missoula, Montana, United States of America
| | - Angela Li
- Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, Kansas, United States of America
| | - Emily K. Grantham
- Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, Kansas, United States of America
| | - Stefan Cerbin
- Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, Kansas, United States of America
| | - Celeste Cummings
- Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, Kansas, United States of America
| | - Marilyn Barragan
- Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, Kansas, United States of America
| | - Rhonda R. Egidy
- Stowers Institute for Medical Research, Kansas City, Missouri, United States of America
| | - Allison R. Scott
- Stowers Institute for Medical Research, Kansas City, Missouri, United States of America
| | - Kate E. Hall
- Stowers Institute for Medical Research, Kansas City, Missouri, United States of America
| | - Anoja Perera
- Stowers Institute for Medical Research, Kansas City, Missouri, United States of America
| | - William D. Gilliland
- Department of Biological Sciences, DePaul University, Chicago, Illinois, United States of America
| | - R. Scott Hawley
- Stowers Institute for Medical Research, Kansas City, Missouri, United States of America
- Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, Kansas, United States of America
| | - Justin P. Blumenstiel
- Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, Kansas, United States of America
| |
Collapse
|
16
|
Parikh RY, Gangaraju VK. Hexavalent chromium-induced epigenetic instability and transposon activation lead to phenotypic variations and tumors in Drosophila. ENVIRONMENTAL EPIGENETICS 2022; 9:dvac030. [PMID: 36743586 PMCID: PMC9892686 DOI: 10.1093/eep/dvac030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 11/22/2022] [Accepted: 12/27/2022] [Indexed: 06/18/2023]
Abstract
Developmental robustness represents the ability of an organism to resist phenotypic variations despite environmental insults and inherent genetic variations. Derailment of developmental robustness leads to phenotypic variations that can get fixed in a population for many generations. Environmental pollution is a significant worldwide problem with detrimental consequences of human development. Understanding the genetic basis for how pollutants affect human development is critical for developing interventional therapies. Here, we report that environmental stress induced by hexavalent chromium, Cr(VI), a potent industrial pollutant, compromises developmental robustness, leading to phenotypic variations in the progeny. These phenotypic variations arise due to epigenetic instability and transposon activation in the somatic tissues of the progeny rather than novel genetic mutations and can be reduced by increasing the dosage of Piwi - a Piwi-interacting RNA-binding protein, in the ovary of the exposed mother. Significantly, the derailment of developmental robustness by Cr(VI) exposure leads to tumors in the progeny, and the predisposition to develop tumors is fixed in the population for at least three generations. Thus, we show for the first time that environmental pollution can derail developmental robustness and predispose the progeny of the exposed population to develop phenotypic variations and tumors.
Collapse
Affiliation(s)
- Rasesh Y Parikh
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, 173 Ashley Avenue, Charleston, SC 29425, USA
- Hollings Cancer Center, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Vamsi K Gangaraju
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, 173 Ashley Avenue, Charleston, SC 29425, USA
- Hollings Cancer Center, Medical University of South Carolina, Charleston, SC 29425, USA
| |
Collapse
|
17
|
Shapiro-Kulnane L, Selengut M, Salz HK. Safeguarding Drosophila female germ cell identity depends on an H3K9me3 mini domain guided by a ZAD zinc finger protein. PLoS Genet 2022; 18:e1010568. [PMID: 36548300 PMCID: PMC9822104 DOI: 10.1371/journal.pgen.1010568] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 01/06/2023] [Accepted: 12/12/2022] [Indexed: 12/24/2022] Open
Abstract
H3K9me3-based gene silencing is a conserved strategy for securing cell fate, but the mechanisms controlling lineage-specific installation of this epigenetic mark remain unclear. In Drosophila, H3K9 methylation plays an essential role in securing female germ cell fate by silencing lineage inappropriate phf7 transcription. Thus, phf7 regulation in the female germline provides a powerful system to dissect the molecular mechanism underlying H3K9me3 deposition onto protein coding genes. Here we used genetic studies to identify the essential cis-regulatory elements, finding that the sequences required for H3K9me3 deposition are conserved across Drosophila species. Transposable elements are also silenced by an H3K9me3-mediated mechanism. But our finding that phf7 regulation does not require the dedicated piRNA pathway components, piwi, aub, rhino, panx, and nxf2, indicates that the mechanisms of H3K9me3 recruitment are distinct. Lastly, we discovered that an uncharacterized member of the zinc finger associated domain (ZAD) containing C2H2 zinc finger protein family, IDENTITY CRISIS (IDC; CG4936), is necessary for H3K9me3 deposition onto phf7. Loss of idc in germ cells interferes with phf7 transcriptional regulation and H3K9me3 deposition, resulting in ectopic PHF7 protein expression. IDC's role is likely to be direct, as it localizes to a conserved domain within the phf7 gene. Collectively, our findings support a model in which IDC guides sequence-specific establishment of an H3K9me3 mini domain, thereby preventing accidental female-to-male programming.
Collapse
Affiliation(s)
- Laura Shapiro-Kulnane
- Department of Genetics and Genome Sciences, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States of America
| | - Micah Selengut
- Department of Genetics and Genome Sciences, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States of America
| | - Helen K. Salz
- Department of Genetics and Genome Sciences, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States of America
| |
Collapse
|
18
|
Ipsaro JJ, Joshua‐Tor L. Developmental roles and molecular mechanisms of Asterix/GTSF1. WIRES RNA 2022; 13:e1716. [PMID: 35108755 PMCID: PMC9539491 DOI: 10.1002/wrna.1716] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 11/29/2021] [Accepted: 11/30/2021] [Indexed: 01/07/2023]
Abstract
Maintenance of germline genomic integrity is critical for the survival of animal species. Consequently, many cellular and molecular processes have evolved to ensure genetic stability during the production of gametes. Here, we describe the discovery, characterization, and emerging molecular mechanisms of the protein Asterix/Gametocyte‐specific factor 1 (GTSF1), an essential gametogenesis factor that is conserved from insects to humans. Beyond its broad importance for healthy germline development, Asterix/GTSF1 has more specific functions in the Piwi‐interacting RNA (piRNA)–RNA interference pathway. There, it contributes to the repression of otherwise deleterious transposons, helping to ensure faithful transmission of genetic information to the next generation. This article is categorized under:Regulatory RNAs/RNAi/Riboswitches > RNAi: Mechanisms of Action Regulatory RNAs/RNAi/Riboswitches > Regulatory RNAs RNA Interactions with Proteins and Other Molecules > RNA‐Protein Complexes RNA Interactions with Proteins and Other Molecules > Protein‐RNA Interactions: Functional Implications
Collapse
Affiliation(s)
- Jonathan J. Ipsaro
- Howard Hughes Medical Institute W.M. Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory Cold Spring Harbor New York USA
| | - Leemor Joshua‐Tor
- Howard Hughes Medical Institute W.M. Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory Cold Spring Harbor New York USA
| |
Collapse
|
19
|
Di Stefano L. All Quiet on the TE Front? The Role of Chromatin in Transposable Element Silencing. Cells 2022; 11:cells11162501. [PMID: 36010577 PMCID: PMC9406493 DOI: 10.3390/cells11162501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 07/27/2022] [Accepted: 08/03/2022] [Indexed: 01/09/2023] Open
Abstract
Transposable elements (TEs) are mobile genetic elements that constitute a sizeable portion of many eukaryotic genomes. Through their mobility, they represent a major source of genetic variation, and their activation can cause genetic instability and has been linked to aging, cancer and neurodegenerative diseases. Accordingly, tight regulation of TE transcription is necessary for normal development. Chromatin is at the heart of TE regulation; however, we still lack a comprehensive understanding of the precise role of chromatin marks in TE silencing and how chromatin marks are established and maintained at TE loci. In this review, I discuss evidence documenting the contribution of chromatin-associated proteins and histone marks in TE regulation across different species with an emphasis on Drosophila and mammalian systems.
Collapse
Affiliation(s)
- Luisa Di Stefano
- Molecular, Cellular and Developmental Biology Department (MCD), Centre de Biologie Intégrative (CBI), University of Toulouse, CNRS, UPS, 31062 Toulouse, France
| |
Collapse
|
20
|
Firsov SY, Kosherova KA, Mukha DV. Identification and functional characterization of the German cockroach, Blattella germanica, short interspersed nuclear elements. PLoS One 2022; 17:e0266699. [PMID: 35696390 PMCID: PMC9191728 DOI: 10.1371/journal.pone.0266699] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Accepted: 03/24/2022] [Indexed: 11/18/2022] Open
Abstract
In recent decades, experimental data has accumulated indicating that short interspersed nuclear elements (SINEs) can play a significant functional role in the regulation of gene expression in the host genome. In addition, molecular markers based on SINE insertion polymorphisms have been developed and are widely used for genetic differentiation of populations of eukaryotic organisms. Using routine bioinformatics analysis and publicly available genomic DNA and small RNA-seq data, we first described nine SINEs in the genome of the German cockroach, Blattella germanica. All described SINEs have tRNA promoters, and the start of their transcription begins 11 bp upstream of an "A" box of these promoters. The number of copies of the described SINEs in the B. germanica genome ranges from several copies to more than a thousand copies in a SINE-specific manner. Some of the described SINEs and their degenerate copies can be localized both in the introns of genes and loci known as piRNA clusters. piRNAs originating from piRNA clusters are shown to be mapped to seven of the nine types of SINEs described, including copies of SINEs localized in gene introns. We speculate that SINEs, localized in the introns of certain genes, may regulate the level of expression of these genes by a PIWI-related molecular mechanism.
Collapse
Affiliation(s)
- Sergei Yu. Firsov
- Vavilov Institute of General Genetics Russian Academy of Sciences, Moscow, Russia
| | - Karina A. Kosherova
- Vavilov Institute of General Genetics Russian Academy of Sciences, Moscow, Russia
| | - Dmitry V. Mukha
- Vavilov Institute of General Genetics Russian Academy of Sciences, Moscow, Russia
| |
Collapse
|
21
|
Schoelz JM, Riddle NC. Functions of HP1 proteins in transcriptional regulation. Epigenetics Chromatin 2022; 15:14. [PMID: 35526078 PMCID: PMC9078007 DOI: 10.1186/s13072-022-00453-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Accepted: 04/18/2022] [Indexed: 01/24/2023] Open
Abstract
In eukaryotes, DNA is packaged into chromatin, which presents significant barriers to transcription. Non-histone chromatin proteins such as the Heterochromatin Protein 1 (HP1) proteins are critical regulators of transcription, contributing to gene regulation through a variety of molecular mechanisms. HP1 proteins are highly conserved, and many eukaryotic genomes contain multiple HP1 genes. Given the presence of multiple HP1 family members within a genome, HP1 proteins can have unique as well as shared functions. Here, we review the mechanisms by which HP1 proteins contribute to the regulation of transcription. Focusing on the Drosophila melanogaster HP1 proteins, we examine the role of these proteins in regulating the transcription of genes, transposable elements, and piRNA clusters. In D. melanogaster, as in other species, HP1 proteins can act as transcriptional repressors and activators. The available data reveal that the precise impact of HP1 proteins on gene expression is highly context dependent, on the specific HP1 protein involved, on its protein partners present, and on the specific chromatin context the interaction occurs in. As a group, HP1 proteins utilize a variety of mechanisms to contribute to transcriptional regulation, including both transcriptional (i.e. chromatin-based) and post-transcriptional (i.e. RNA-based) processes. Despite extensive studies of this important protein family, open questions regarding their functions in gene regulation remain, specifically regarding the role of hetero- versus homodimerization and post-translational modifications of HP1 proteins.
Collapse
Affiliation(s)
- John M Schoelz
- Department of Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Nicole C Riddle
- Department of Biology, University of Alabama at Birmingham, Birmingham, AL, USA.
| |
Collapse
|
22
|
La Rocca G, Cavalieri V. Roles of the Core Components of the Mammalian miRISC in Chromatin Biology. Genes (Basel) 2022; 13:414. [PMID: 35327968 PMCID: PMC8954937 DOI: 10.3390/genes13030414] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 02/20/2022] [Accepted: 02/23/2022] [Indexed: 12/16/2022] Open
Abstract
The Argonaute (AGO) and the Trinucleotide Repeat Containing 6 (TNRC6) family proteins are the core components of the mammalian microRNA-induced silencing complex (miRISC), the machinery that mediates microRNA function in the cytoplasm. The cytoplasmic miRISC-mediated post-transcriptional gene repression has been established as the canonical mechanism through which AGO and TNRC6 proteins operate. However, growing evidence points towards an additional mechanism through which AGO and TNRC6 regulate gene expression in the nucleus. While several mechanisms through which miRISC components function in the nucleus have been described, in this review we aim to summarize the major findings that have shed light on the role of AGO and TNRC6 in mammalian chromatin biology and on the implications these novel mechanisms may have in our understanding of regulating gene expression.
Collapse
Affiliation(s)
- Gaspare La Rocca
- Cancer Biology and Genetics Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Vincenzo Cavalieri
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies, University of Palermo, 90128 Palermo, Italy
| |
Collapse
|
23
|
Andreev VI, Yu C, Wang J, Schnabl J, Tirian L, Gehre M, Handler D, Duchek P, Novatchkova M, Baumgartner L, Meixner K, Sienski G, Patel DJ, Brennecke J. Panoramix SUMOylation on chromatin connects the piRNA pathway to the cellular heterochromatin machinery. Nat Struct Mol Biol 2022; 29:130-142. [PMID: 35173350 DOI: 10.1038/s41594-022-00721-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Accepted: 12/30/2021] [Indexed: 11/09/2022]
Abstract
Nuclear Argonaute proteins, guided by small RNAs, mediate sequence-specific heterochromatin formation. The molecular principles that link Argonaute-small RNA complexes to cellular heterochromatin effectors on binding to nascent target RNAs are poorly understood. Here, we explain the mechanism by which the PIWI-interacting RNA (piRNA) pathway connects to the heterochromatin machinery in Drosophila. We find that Panoramix, a corepressor required for piRNA-guided heterochromatin formation, is SUMOylated on chromatin in a Piwi-dependent manner. SUMOylation, together with an amphipathic LxxLL motif in Panoramix's intrinsically disordered repressor domain, are necessary and sufficient to recruit Small ovary (Sov), a multi-zinc-finger protein essential for general heterochromatin formation and viability. Structure-guided mutations that eliminate the Panoramix-Sov interaction or that prevent SUMOylation of Panoramix uncouple Sov from the piRNA pathway, resulting in viable but sterile flies in which Piwi-targeted transposons are derepressed. Thus, Piwi engages the heterochromatin machinery specifically at transposon loci by coupling recruitment of a corepressor to nascent transcripts with its SUMOylation.
Collapse
Affiliation(s)
- Veselin I Andreev
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), Vienna, Austria.,Vienna BioCenter PhD Program, Doctoral School of the University of Vienna and Medical University of Vienna, Vienna, Austria
| | - Changwei Yu
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), Vienna, Austria
| | - Juncheng Wang
- Structural Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Jakob Schnabl
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), Vienna, Austria.,Vienna BioCenter PhD Program, Doctoral School of the University of Vienna and Medical University of Vienna, Vienna, Austria
| | - Laszlo Tirian
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), Vienna, Austria
| | - Maja Gehre
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), Vienna, Austria
| | - Dominik Handler
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), Vienna, Austria
| | - Peter Duchek
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), Vienna, Austria
| | - Maria Novatchkova
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), Vienna, Austria
| | - Lisa Baumgartner
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), Vienna, Austria.,Vienna BioCenter PhD Program, Doctoral School of the University of Vienna and Medical University of Vienna, Vienna, Austria
| | - Katharina Meixner
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), Vienna, Austria
| | - Grzegorz Sienski
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), Vienna, Austria.,Vienna BioCenter PhD Program, Doctoral School of the University of Vienna and Medical University of Vienna, Vienna, Austria
| | - Dinshaw J Patel
- Structural Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Julius Brennecke
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), Vienna, Austria.
| |
Collapse
|
24
|
Fefelova EA, Pleshakova IM, Mikhaleva EA, Pirogov SA, Poltorachenko V, Abramov Y, Romashin D, Shatskikh A, Blokh R, Gvozdev V, Klenov M. Impaired function of rDNA transcription initiation machinery leads to derepression of ribosomal genes with insertions of R2 retrotransposon. Nucleic Acids Res 2022; 50:867-884. [PMID: 35037046 PMCID: PMC8789037 DOI: 10.1093/nar/gkab1276] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Revised: 11/21/2021] [Accepted: 12/14/2021] [Indexed: 12/14/2022] Open
Abstract
Eukaryotic genomes harbor hundreds of rRNA genes, many of which are transcriptionally silent. However, little is known about selective regulation of individual rDNA units. In Drosophila melanogaster, some rDNA repeats contain insertions of the R2 retrotransposon, which is capable to be transcribed only as part of pre-rRNA molecules. rDNA units with R2 insertions are usually inactivated, although R2 expression may be beneficial in cells with decreased rDNA copy number. Here we found that R2-inserted rDNA units are enriched with HP1a and H3K9me3 repressive mark, whereas disruption of the heterochromatin components slightly affects their silencing in ovarian germ cells. Surprisingly, we observed a dramatic upregulation of R2-inserted rRNA genes in ovaries lacking Udd (Under-developed) or other subunits (TAF1b and TAF1c-like) of the SL1-like complex, which is homologues to mammalian Selective factor 1 (SL1) involved in rDNA transcription initiation. Derepression of rRNA genes with R2 insertions was accompanied by a reduction of H3K9me3 and HP1a enrichment. We suggest that the impairment of the SL1-like complex affects a mechanism of selective activation of intact rDNA units which competes with heterochromatin formation. We also propose that R2 derepression may serve as an adaptive response to compromised rRNA synthesis.
Collapse
Affiliation(s)
- Elena A Fefelova
- Department of Molecular Genetics of the Cell, Institute of Molecular Genetics of National Research Centre «Kurchatov Institute», Moscow 123182, Russia
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena 91125, USA
| | - Irina M Pleshakova
- Department of Molecular Genetics of the Cell, Institute of Molecular Genetics of National Research Centre «Kurchatov Institute», Moscow 123182, Russia
- Laboratory for Neurobiology of Memory, P.K. Anokhin Institute of Normal Physiology, Moscow 125315, Russia
| | - Elena A Mikhaleva
- Department of Molecular Genetics of the Cell, Institute of Molecular Genetics of National Research Centre «Kurchatov Institute», Moscow 123182, Russia
| | - Sergei A Pirogov
- Department of Molecular Genetics of the Cell, Institute of Molecular Genetics of National Research Centre «Kurchatov Institute», Moscow 123182, Russia
| | - Valentin A Poltorachenko
- Department of Molecular Genetics of the Cell, Institute of Molecular Genetics of National Research Centre «Kurchatov Institute», Moscow 123182, Russia
| | - Yuri A Abramov
- Department of Molecular Genetics of the Cell, Institute of Molecular Genetics of National Research Centre «Kurchatov Institute», Moscow 123182, Russia
| | - Daniil D Romashin
- Laboratory of Precision Biosystems, V. N. Orekhovich Institute of Biomedical Chemistry, 10 Pogodinskaya St., Moscow 119121, Russia
| | - Aleksei S Shatskikh
- Department of Molecular Genetics of the Cell, Institute of Molecular Genetics of National Research Centre «Kurchatov Institute», Moscow 123182, Russia
| | - Roman S Blokh
- Department of Molecular Genetics of the Cell, Institute of Molecular Genetics of National Research Centre «Kurchatov Institute», Moscow 123182, Russia
- Department of Functional Genomics, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilova Street, Moscow 119334, Russia
| | - Vladimir A Gvozdev
- Department of Molecular Genetics of the Cell, Institute of Molecular Genetics of National Research Centre «Kurchatov Institute», Moscow 123182, Russia
| | - Mikhail S Klenov
- Department of Molecular Genetics of the Cell, Institute of Molecular Genetics of National Research Centre «Kurchatov Institute», Moscow 123182, Russia
| |
Collapse
|
25
|
ElMaghraby MF, Tirian L, Senti KA, Meixner K, Brennecke J. A genetic toolkit for studying transposon control in the Drosophila melanogaster ovary. Genetics 2022; 220:iyab179. [PMID: 34718559 PMCID: PMC8733420 DOI: 10.1093/genetics/iyab179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Accepted: 09/19/2021] [Indexed: 11/12/2022] Open
Abstract
Argonaute proteins of the PIWI clade complexed with PIWI-interacting RNAs (piRNAs) protect the animal germline genome by silencing transposable elements. One of the leading experimental systems for studying piRNA biology is the Drosophila melanogaster ovary. In addition to classical mutagenesis, transgenic RNA interference (RNAi), which enables tissue-specific silencing of gene expression, plays a central role in piRNA research. Here, we establish a versatile toolkit focused on piRNA biology that combines germline transgenic RNAi, GFP marker lines for key proteins of the piRNA pathway, and reporter transgenes to establish genetic hierarchies. We compare constitutive, pan-germline RNAi with an equally potent transgenic RNAi system that is activated only after germ cell cyst formation. Stage-specific RNAi allows us to investigate the role of genes essential for germline cell survival, for example, nuclear RNA export or the SUMOylation pathway, in piRNA-dependent and independent transposon silencing. Our work forms the basis for an expandable genetic toolkit provided by the Vienna Drosophila Resource Center.
Collapse
Affiliation(s)
- Mostafa F ElMaghraby
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), Vienna 1030, Austria
- Vienna BioCenter PhD Program, Doctoral School at the University of Vienna and Medical University of Vienna, Vienna 1030, Austria
| | - Laszlo Tirian
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), Vienna 1030, Austria
| | - Kirsten-André Senti
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), Vienna 1030, Austria
| | - Katharina Meixner
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), Vienna 1030, Austria
| | - Julius Brennecke
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), Vienna 1030, Austria
| |
Collapse
|
26
|
Saito K. Drosophila Genetic Resources for Elucidating piRNA Pathway. Methods Mol Biol 2022; 2509:135-141. [PMID: 35796961 DOI: 10.1007/978-1-0716-2380-0_8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Emerging evidence indicates that PIWI proteins, in collaboration with PIWI-interacting RNAs (piRNAs), play a critical role in gonadal development and retrotransposon silencing in metazoans. Numerous studies have characterized the mechanism of retrotransposon silencing and identified dozens of factors involved in the piRNA pathways. Drosophila is an attractive model organism for piRNA studies due to its great availability of genetic tools and the low cost of maintenance. Here, I introduce Drosophila genetic resources and techniques valuable for studying piRNA pathway genes via their impact on retrotransposon silencing.
Collapse
Affiliation(s)
- Kuniaki Saito
- Invertebrate Genetics Laboratory, Department of Chromosome Science, National Institute of Genetics, Research Organization of Information and Systems (ROIS), Mishima, Shizuoka, Japan.
- Division of Invertebrate Genetics, Department of Genetics, The Graduate University for Advanced Studies (SOKENDAI), Mishima, Shizuoka, Japan.
| |
Collapse
|
27
|
To export, or not to export: how nuclear export factor variants resolve Piwi's dilemma. Biochem Soc Trans 2021; 49:2073-2079. [PMID: 34643228 DOI: 10.1042/bst20201171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 09/06/2021] [Accepted: 09/15/2021] [Indexed: 11/17/2022]
Abstract
Piwi-interacting RNAs (piRNAs) defend animal gonads by guiding PIWI-clade Argonaute proteins to silence transposons. The nuclear Piwi/piRNA complexes confer transcriptional repression of transposons, which is accompanied with heterochromatin formation at target loci. On the other hand, piRNA clusters, genomic loci that transcribe piRNA precursors composed of transposon fragments, are often recognized by piRNAs to define their heterochromatic identity. Therefore, Piwi/piRNA complexes must resolve this conundrum of silencing transposons while allowing the expression of piRNA precursors, at least in Drosophila germlines. This review is focused on recent advances how the piRNA pathway deals with this genetic conflict.
Collapse
|
28
|
Li D, Taylor DH, van Wolfswinkel JC. PIWI-mediated control of tissue-specific transposons is essential for somatic cell differentiation. Cell Rep 2021; 37:109776. [PMID: 34610311 PMCID: PMC8532177 DOI: 10.1016/j.celrep.2021.109776] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 07/27/2021] [Accepted: 09/07/2021] [Indexed: 12/24/2022] Open
Abstract
PIWI proteins are known as mediators of transposon silencing in animal germlines but are also found in adult pluripotent stem cells of highly regenerative animals, where they are essential for regeneration. Study of the nuclear PIWI protein SMEDWI-2 in the planarian somatic stem cell system reveals an intricate interplay between transposons and cell differentiation in which a subset of transposons is inevitably activated during cell differentiation, and the PIWI protein is required to regain control. Absence of SMEDWI-2 leads to tissue-specific transposon derepression related to cell-type-specific chromatin remodeling events and in addition causes reduced accessibility of lineage-specific genes and defective cell differentiation, resulting in fatal tissue dysfunction. Finally, we show that additional PIWI proteins provide a stem-cell-specific second layer of protection in planarian neoblasts. These findings reveal a far-reaching role of PIWI proteins and PIWI-interacting RNAs (piRNAs) in stem cell biology and cell differentiation.
Collapse
Affiliation(s)
- Danyan Li
- Department of Molecular Cellular and Developmental Biology, Yale University, New Haven, CT 06511, USA
| | - David H Taylor
- Department of Molecular Cellular and Developmental Biology, Yale University, New Haven, CT 06511, USA
| | - Josien C van Wolfswinkel
- Department of Molecular Cellular and Developmental Biology, Yale University, New Haven, CT 06511, USA.
| |
Collapse
|
29
|
Gibert JM, Peronnet F. The Paramount Role of Drosophila melanogaster in the Study of Epigenetics: From Simple Phenotypes to Molecular Dissection and Higher-Order Genome Organization. INSECTS 2021; 12:884. [PMID: 34680653 PMCID: PMC8537509 DOI: 10.3390/insects12100884] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 09/24/2021] [Accepted: 09/26/2021] [Indexed: 01/06/2023]
Abstract
Drosophila melanogaster has played a paramount role in epigenetics, the study of changes in gene function inherited through mitosis or meiosis that are not due to changes in the DNA sequence. By analyzing simple phenotypes, such as the bristle position or cuticle pigmentation, as read-outs of regulatory processes, the identification of mutated genes led to the discovery of major chromatin regulators. These are often conserved in distantly related organisms such as vertebrates or even plants. Many of them deposit, recognize, or erase post-translational modifications on histones (histone marks). Others are members of chromatin remodeling complexes that move, eject, or exchange nucleosomes. We review the role of D. melanogaster research in three epigenetic fields: Heterochromatin formation and maintenance, the repression of transposable elements by piRNAs, and the regulation of gene expression by the antagonistic Polycomb and Trithorax complexes. We then describe how genetic tools available in D. melanogaster allowed to examine the role of histone marks and show that some histone marks are dispensable for gene regulation, whereas others play essential roles. Next, we describe how D. melanogaster has been particularly important in defining chromatin types, higher-order chromatin structures, and their dynamic changes during development. Lastly, we discuss the role of epigenetics in a changing environment.
Collapse
Affiliation(s)
- Jean-Michel Gibert
- Centre National de la Recherche Scientifique (CNRS), Laboratoire de Biologie du Développement (LBD), Institut de Biologie Paris Seine (IBPS), Sorbonne Université, 75005 Paris, France
| | - Frédérique Peronnet
- Centre National de la Recherche Scientifique (CNRS), Laboratoire de Biologie du Développement (LBD), Institut de Biologie Paris Seine (IBPS), Sorbonne Université, 75005 Paris, France
| |
Collapse
|
30
|
Zhang G, Yu T, Parhad SS, Ho S, Weng Z, Theurkauf WE. piRNA-independent transposon silencing by the Drosophila THO complex. Dev Cell 2021; 56:2623-2635.e5. [PMID: 34547226 DOI: 10.1016/j.devcel.2021.08.021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 06/18/2021] [Accepted: 08/27/2021] [Indexed: 12/19/2022]
Abstract
piRNAs guide Piwi/Panoramix-dependent H3K9me3 chromatin modification and transposon silencing during Drosophila germline development. The THO RNA export complex is composed of Hpr1, Tho2, and Thoc5-7. Null thoc7 mutations, which displace Thoc5 and Thoc6 from a Tho2-Hpr1 subcomplex, reduce expression of a subset of germline piRNAs and increase transposon expression, suggesting that THO silences transposons by promoting piRNA biogenesis. Here, we show that the thoc7-null mutant combination increases transposon transcription but does not reduce anti-sense piRNAs targeting half of the transcriptionally activated transposon families. These mutations also fail to reduce piRNA-guided H3K9me3 chromatin modification or block Panoramix-dependent silencing of a reporter transgene, and unspliced transposon transcripts co-precipitate with THO through a Piwi- and Panoramix-independent mechanism. Mutations in piwi also dominantly enhance germline defects associated with thoc7-null alleles. THO thus functions in a piRNA-independent transposon-silencing pathway, which acts cooperatively with Piwi to support germline development.
Collapse
Affiliation(s)
- Gen Zhang
- Program in Molecular Medicine, University of Massachusetts Medical School, 373 Plantation Street, Worcester, MA 01605, USA
| | - Tianxiong Yu
- Program in Bioinformatics and Integrative Biology, University of Massachusetts Medical School, 373 Plantation Street, Worcester, MA 01605, USA; Department of Bioinformatics, School of Life Sciences and Technology, Tongji University, Shanghai, People's Republic of China
| | - Swapnil S Parhad
- Program in Molecular Medicine, University of Massachusetts Medical School, 373 Plantation Street, Worcester, MA 01605, USA
| | - Samantha Ho
- Program in Molecular Medicine, University of Massachusetts Medical School, 373 Plantation Street, Worcester, MA 01605, USA
| | - Zhiping Weng
- Program in Bioinformatics and Integrative Biology, University of Massachusetts Medical School, 373 Plantation Street, Worcester, MA 01605, USA.
| | - William E Theurkauf
- Program in Molecular Medicine, University of Massachusetts Medical School, 373 Plantation Street, Worcester, MA 01605, USA.
| |
Collapse
|
31
|
Chen P, Luo Y, Aravin AA. RDC complex executes a dynamic piRNA program during Drosophila spermatogenesis to safeguard male fertility. PLoS Genet 2021; 17:e1009591. [PMID: 34473737 PMCID: PMC8412364 DOI: 10.1371/journal.pgen.1009591] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2020] [Accepted: 05/10/2021] [Indexed: 11/19/2022] Open
Abstract
piRNAs are small non-coding RNAs that guide the silencing of transposons and other targets in animal gonads. In Drosophila female germline, many piRNA source loci dubbed “piRNA clusters” lack hallmarks of active genes and exploit an alternative path for transcription, which relies on the Rhino-Deadlock-Cutoff (RDC) complex. RDC was thought to be absent in testis, so it remains to date unknown how piRNA cluster transcription is regulated in the male germline. We found that components of RDC complex are expressed in male germ cells during early spermatogenesis, from germline stem cells (GSCs) to early spermatocytes. RDC is essential for expression of dual-strand piRNA clusters and transposon silencing in testis; however, it is dispensable for expression of Y-linked Suppressor of Stellate piRNAs and therefore Stellate silencing. Despite intact Stellate repression, males lacking RDC exhibited compromised fertility accompanied by germline DNA damage and GSC loss. Thus, piRNA-guided repression is essential for normal spermatogenesis beyond Stellate silencing. While RDC associates with multiple piRNA clusters in GSCs and early spermatogonia, its localization changes in later stages as RDC concentrates on a single X-linked locus, AT-chX. Dynamic RDC localization is paralleled by changes in piRNA cluster expression, indicating that RDC executes a fluid piRNA program during different stages of spermatogenesis. These results disprove the common belief that RDC is dispensable for piRNA biogenesis in testis and uncover the unexpected, sexually dimorphic and dynamic behavior of a core piRNA pathway machinery. Large fractions of eukaryotic genomes are occupied by mobile genetic elements called transposons. Active transposons can move in the genome causing DNA damage and mutations, while inactive copies can contribute to chromosome organization and regulation of gene expression. Host cells employ several mechanisms to discriminate transposons from other genes and repress transposon activities. In germ cells, a conserved class of short RNAs called Piwi-interacting (pi)RNAs recognize target RNAs in both the nucleus and cytoplasm and then guide transposon repression by preventing their transcription and destroying their RNAs. piRNAs are encoded in extended genomic regions dubbed piRNA clusters. Previously, composition and regulation of piRNA clusters were studied in the female germline of fruit flies, where a nuclear protein complex, the RDC complex, was shown to promote non-canonical transcription of these regions. However, RDC was believed to be dispensable in males. Here, we showed that RDC is essential for transposon repression in males, and males lacking RDC exhibit compromised fertility and loss of germ cells. We found that RDC binds multiple piRNA clusters in early germ cells but concentrates on a single locus at later stages. Our results indicate dynamic regulation of loci that produce piRNAs and, therefore, piRNA targets throughout spermatogenesis.
Collapse
Affiliation(s)
- Peiwei Chen
- California Institute of Technology, Division of Biology and Biological Engineering, Pasadena, California, United States of America
- * E-mail: (PC); (AAA)
| | - Yicheng Luo
- California Institute of Technology, Division of Biology and Biological Engineering, Pasadena, California, United States of America
| | - Alexei A. Aravin
- California Institute of Technology, Division of Biology and Biological Engineering, Pasadena, California, United States of America
- * E-mail: (PC); (AAA)
| |
Collapse
|
32
|
Onishi R, Yamanaka S, Siomi MC. piRNA- and siRNA-mediated transcriptional repression in Drosophila, mice, and yeast: new insights and biodiversity. EMBO Rep 2021; 22:e53062. [PMID: 34347367 PMCID: PMC8490990 DOI: 10.15252/embr.202153062] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 06/10/2021] [Accepted: 07/19/2021] [Indexed: 12/26/2022] Open
Abstract
The PIWI‐interacting RNA (piRNA) pathway acts as a self‐defense mechanism against transposons to maintain germline genome integrity. Failures in the piRNA pathway cause DNA damage in the germline genome, disturbing inheritance of “correct” genetic information by the next generations and leading to infertility. piRNAs execute transposon repression in two ways: degrading their RNA transcripts and compacting the genomic loci via heterochromatinization. The former event is mechanistically similar to siRNA‐mediated RNA cleavage that occurs in the cytoplasm and has been investigated in many species including nematodes, fruit flies, and mammals. The latter event seems to be mechanistically parallel to siRNA‐centered kinetochore assembly and subsequent chromosome segregation, which has so far been studied particularly in fission yeast. Despite the interspecies conservations, the overall schemes of the nuclear events show clear biodiversity across species. In this review, we summarize the recent progress regarding piRNA‐mediated transcriptional silencing in Drosophila and discuss the biodiversity by comparing it with the equivalent piRNA‐mediated system in mice and the siRNA‐mediated system in fission yeast.
Collapse
Affiliation(s)
- Ryo Onishi
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Soichiro Yamanaka
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Mikiko C Siomi
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| |
Collapse
|
33
|
Iwasaki YW, Sriswasdi S, Kinugasa Y, Adachi J, Horikoshi Y, Shibuya A, Iwasaki W, Tashiro S, Tomonaga T, Siomi H. Piwi-piRNA complexes induce stepwise changes in nuclear architecture at target loci. EMBO J 2021; 40:e108345. [PMID: 34337769 PMCID: PMC8441340 DOI: 10.15252/embj.2021108345] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Revised: 07/04/2021] [Accepted: 07/09/2021] [Indexed: 12/25/2022] Open
Abstract
PIWI‐interacting RNAs (piRNAs) are germline‐specific small RNAs that form effector complexes with PIWI proteins (Piwi–piRNA complexes) and play critical roles for preserving genomic integrity by repressing transposable elements (TEs). Drosophila Piwi transcriptionally silences specific targets through heterochromatin formation and increases histone H3K9 methylation (H3K9me3) and histone H1 deposition at these loci, with nuclear RNA export factor variant Nxf2 serving as a co‐factor. Using ChEP and DamID‐seq, we now uncover a Piwi/Nxf2‐dependent target association with nuclear lamins. Hi‐C analysis of Piwi or Nxf2‐depleted cells reveals decreased intra‐TAD and increased inter‐TAD interactions in regions harboring Piwi–piRNA target TEs. Using a forced tethering system, we analyze the functional effects of Piwi–piRNA/Nxf2‐mediated recruitment of piRNA target regions to the nuclear periphery. Removal of active histone marks is followed by transcriptional silencing, chromatin conformational changes, and H3K9me3 and H1 association. Our data show that the Piwi–piRNA pathway can induce stepwise changes in nuclear architecture and chromatin state at target loci for transcriptional silencing.
Collapse
Affiliation(s)
- Yuka W Iwasaki
- Department of Molecular Biology, Keio University School of Medicine, Tokyo, Japan.,Japan Science and Technology Agency (JST), Precursory Research for Embryonic Science and Technology (PRESTO), Saitama, Japan
| | - Sira Sriswasdi
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan.,Computational Molecular Biology Group, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand.,Research Affairs, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Yasuha Kinugasa
- Department of Cellular Biology, Research Institute for Radiation Biology Medicine, Hiroshima University, Hiroshima, Japan
| | - Jun Adachi
- Laboratory of Proteome Research, National Institutes of Biomedical Innovation, Health and Nutrition, Osaka, Japan
| | - Yasunori Horikoshi
- Department of Cellular Biology, Research Institute for Radiation Biology Medicine, Hiroshima University, Hiroshima, Japan
| | - Aoi Shibuya
- Department of Molecular Biology, Keio University School of Medicine, Tokyo, Japan
| | - Wataru Iwasaki
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Satoshi Tashiro
- Department of Cellular Biology, Research Institute for Radiation Biology Medicine, Hiroshima University, Hiroshima, Japan
| | - Takeshi Tomonaga
- Laboratory of Proteome Research, National Institutes of Biomedical Innovation, Health and Nutrition, Osaka, Japan
| | - Haruhiko Siomi
- Department of Molecular Biology, Keio University School of Medicine, Tokyo, Japan
| |
Collapse
|
34
|
Fabry MH, Falconio FA, Joud F, Lythgoe EK, Czech B, Hannon GJ. Maternally inherited piRNAs direct transient heterochromatin formation at active transposons during early Drosophila embryogenesis. eLife 2021; 10:e68573. [PMID: 34236313 PMCID: PMC8352587 DOI: 10.7554/elife.68573] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 07/07/2021] [Indexed: 12/12/2022] Open
Abstract
The PIWI-interacting RNA (piRNA) pathway controls transposon expression in animal germ cells, thereby ensuring genome stability over generations. In Drosophila, piRNAs are intergenerationally inherited through the maternal lineage, and this has demonstrated importance in the specification of piRNA source loci and in silencing of I- and P-elements in the germ cells of daughters. Maternally inherited Piwi protein enters somatic nuclei in early embryos prior to zygotic genome activation and persists therein for roughly half of the time required to complete embryonic development. To investigate the role of the piRNA pathway in the embryonic soma, we created a conditionally unstable Piwi protein. This enabled maternally deposited Piwi to be cleared from newly laid embryos within 30 min and well ahead of the activation of zygotic transcription. Examination of RNA and protein profiles over time, and correlation with patterns of H3K9me3 deposition, suggests a role for maternally deposited Piwi in attenuating zygotic transposon expression in somatic cells of the developing embryo. In particular, robust deposition of piRNAs targeting roo, an element whose expression is mainly restricted to embryonic development, results in the deposition of transient heterochromatic marks at active roo insertions. We hypothesize that roo, an extremely successful mobile element, may have adopted a lifestyle of expression in the embryonic soma to evade silencing in germ cells.
Collapse
Affiliation(s)
- Martin H Fabry
- CRUK Cambridge Institute, University of Cambridge, Li Ka Shing CentreCambridgeUnited Kingdom
| | - Federica A Falconio
- CRUK Cambridge Institute, University of Cambridge, Li Ka Shing CentreCambridgeUnited Kingdom
| | - Fadwa Joud
- CRUK Cambridge Institute, University of Cambridge, Li Ka Shing CentreCambridgeUnited Kingdom
| | - Emily K Lythgoe
- CRUK Cambridge Institute, University of Cambridge, Li Ka Shing CentreCambridgeUnited Kingdom
| | - Benjamin Czech
- CRUK Cambridge Institute, University of Cambridge, Li Ka Shing CentreCambridgeUnited Kingdom
| | - Gregory J Hannon
- CRUK Cambridge Institute, University of Cambridge, Li Ka Shing CentreCambridgeUnited Kingdom
| |
Collapse
|
35
|
Herbette M, Wei X, Chang CH, Larracuente AM, Loppin B, Dubruille R. Distinct spermiogenic phenotypes underlie sperm elimination in the Segregation Distorter meiotic drive system. PLoS Genet 2021; 17:e1009662. [PMID: 34228705 PMCID: PMC8284685 DOI: 10.1371/journal.pgen.1009662] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 07/16/2021] [Accepted: 06/10/2021] [Indexed: 12/28/2022] Open
Abstract
Segregation Distorter (SD) is a male meiotic drive system in Drosophila melanogaster. Males heterozygous for a selfish SD chromosome rarely transmit the homologous SD+ chromosome. It is well established that distortion results from an interaction between Sd, the primary distorting locus on the SD chromosome and its target, a satellite DNA called Rsp, on the SD+ chromosome. However, the molecular and cellular mechanisms leading to post-meiotic SD+ sperm elimination remain unclear. Here we show that SD/SD+ males of different genotypes but with similarly strong degrees of distortion have distinct spermiogenic phenotypes. In some genotypes, SD+ spermatids fail to fully incorporate protamines after the removal of histones, and degenerate during the individualization stage of spermiogenesis. In contrast, in other SD/SD+ genotypes, protamine incorporation appears less disturbed, yet spermatid nuclei are abnormally compacted, and mature sperm nuclei are eventually released in the seminal vesicle. Our analyses of different SD+ chromosomes suggest that the severity of the spermiogenic defects associates with the copy number of the Rsp satellite. We propose that when Rsp copy number is very high (> 2000), spermatid nuclear compaction defects reach a threshold that triggers a checkpoint controlling sperm chromatin quality to eliminate abnormal spermatids during individualization.
Collapse
Affiliation(s)
- Marion Herbette
- Laboratoire de Biologie et Modélisation de la Cellule, CNRS UMR 5239, École Normale Supérieure de Lyon, University of Lyon, Lyon, France
| | - Xiaolu Wei
- University of Rochester Medical Center, Department of Biomedical Genetics, Rochester, New York, United States of America
| | - Ching-Ho Chang
- University of Rochester Department of Biology, Rochester, New York, United States of America
| | - Amanda M. Larracuente
- University of Rochester Department of Biology, Rochester, New York, United States of America
| | - Benjamin Loppin
- Laboratoire de Biologie et Modélisation de la Cellule, CNRS UMR 5239, École Normale Supérieure de Lyon, University of Lyon, Lyon, France
| | - Raphaëlle Dubruille
- Laboratoire de Biologie et Modélisation de la Cellule, CNRS UMR 5239, École Normale Supérieure de Lyon, University of Lyon, Lyon, France
| |
Collapse
|
36
|
Ohtani H, Iwasaki YW. Rewiring of chromatin state and gene expression by transposable elements. Dev Growth Differ 2021; 63:262-273. [DOI: 10.1111/dgd.12735] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 05/06/2021] [Accepted: 05/06/2021] [Indexed: 01/18/2023]
Affiliation(s)
- Hitoshi Ohtani
- Laboratory of Genome and Epigenome Dynamics Department of Animal Sciences Graduate School of Bioagricultural Sciences Nagoya University Nagoya Japan
| | - Yuka W. Iwasaki
- Department of Molecular Biology Keio University School of Medicine Tokyo Japan
- Japan Science and Technology Agency (JST) Precursory Research for Embryonic Science and Technology (PRESTO) Saitama Japan
| |
Collapse
|
37
|
Joosten J, Taşköprü E, Jansen PWTC, Pennings B, Vermeulen M, Van Rij RP. PIWI proteomics identifies Atari and Pasilla as piRNA biogenesis factors in Aedes mosquitoes. Cell Rep 2021; 35:109073. [PMID: 33951430 DOI: 10.1016/j.celrep.2021.109073] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 03/03/2021] [Accepted: 04/12/2021] [Indexed: 01/29/2023] Open
Abstract
As in most arthropods, the PIWI-interacting RNA (piRNA) pathway in the vector mosquito Aedes aegypti is active in diverse biological processes in both soma and germline. To gain insights into piRNA biogenesis and effector complexes, we mapped the interactomes of the somatic PIWI proteins Ago3, Piwi4, Piwi5, and Piwi6 and identify numerous specific interactors as well as cofactors associated with multiple PIWI proteins. We describe the Piwi5 interactor AAEL014965, the direct ortholog of the Drosophila splicing factor pasilla. We find that Ae. aegypti Pasilla encodes a nuclear isoform and a cytoplasmic isoform, the latter of which is required for efficient piRNA production. In addition, we characterize a splice variant of the Tudor protein AAEL008101/Atari that associates with Ago3 and forms a scaffold for PIWI proteins and target RNAs to promote ping-pong amplification of piRNAs. Our study provides a useful resource for follow-up studies of somatic piRNA biogenesis, mechanism, and function in Aedes mosquitoes.
Collapse
Affiliation(s)
- Joep Joosten
- Department of Medical Microbiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, P.O. Box 9101, 6500 HB Nijmegen, the Netherlands
| | - Ezgi Taşköprü
- Department of Medical Microbiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, P.O. Box 9101, 6500 HB Nijmegen, the Netherlands
| | - Pascal W T C Jansen
- Department of Molecular Biology, Faculty of Science, Radboud Institute for Molecular Life Sciences, Oncode Institute, Radboud University Nijmegen, 6525 GA Nijmegen, the Netherlands
| | - Bas Pennings
- Department of Medical Microbiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, P.O. Box 9101, 6500 HB Nijmegen, the Netherlands
| | - Michiel Vermeulen
- Department of Molecular Biology, Faculty of Science, Radboud Institute for Molecular Life Sciences, Oncode Institute, Radboud University Nijmegen, 6525 GA Nijmegen, the Netherlands
| | - Ronald P Van Rij
- Department of Medical Microbiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, P.O. Box 9101, 6500 HB Nijmegen, the Netherlands.
| |
Collapse
|
38
|
Schnabl J, Wang J, Hohmann U, Gehre M, Batki J, Andreev VI, Purkhauser K, Fasching N, Duchek P, Novatchkova M, Mechtler K, Plaschka C, Patel DJ, Brennecke J. Molecular principles of Piwi-mediated cotranscriptional silencing through the dimeric SFiNX complex. Genes Dev 2021; 35:392-409. [PMID: 33574069 PMCID: PMC7919418 DOI: 10.1101/gad.347989.120] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Accepted: 01/22/2021] [Indexed: 12/14/2022]
Abstract
Nuclear Argonaute proteins, guided by their bound small RNAs to nascent target transcripts, mediate cotranscriptional silencing of transposons and repetitive genomic loci through heterochromatin formation. The molecular mechanisms involved in this process are incompletely understood. Here, we show that the SFiNX complex, a silencing mediator downstream from nuclear Piwi-piRNA complexes in Drosophila, facilitates cotranscriptional silencing as a homodimer. The dynein light chain protein Cut up/LC8 mediates SFiNX dimerization, and its function can be bypassed by a heterologous dimerization domain, arguing for a constitutive SFiNX dimer. Dimeric, but not monomeric SFiNX, is capable of forming molecular condensates in a nucleic acid-stimulated manner. Mutations that prevent SFiNX dimerization result in loss of condensate formation in vitro and the inability of Piwi to initiate heterochromatin formation and silence transposons in vivo. We propose that multivalent SFiNX-nucleic acid interactions are critical for heterochromatin establishment at piRNA target loci in a cotranscriptional manner.
Collapse
Affiliation(s)
- Jakob Schnabl
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), 1030 Vienna, Austria
- Vienna BioCenter PhD Program, Doctoral School at the University of Vienna and Medical University of Vienna, 1030 Vienna, Austria
| | - Juncheng Wang
- Structural Biology Program, Memorial Sloan Kettering Cancer Center, New York, New York 10065, USA
| | - Ulrich Hohmann
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), 1030 Vienna, Austria
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), 1030 Vienna, Austria
| | - Maja Gehre
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), 1030 Vienna, Austria
| | - Julia Batki
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), 1030 Vienna, Austria
| | - Veselin I Andreev
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), 1030 Vienna, Austria
- Vienna BioCenter PhD Program, Doctoral School at the University of Vienna and Medical University of Vienna, 1030 Vienna, Austria
| | - Kim Purkhauser
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), 1030 Vienna, Austria
| | - Nina Fasching
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), 1030 Vienna, Austria
| | - Peter Duchek
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), 1030 Vienna, Austria
| | - Maria Novatchkova
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), 1030 Vienna, Austria
| | - Karl Mechtler
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), 1030 Vienna, Austria
| | - Clemens Plaschka
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), 1030 Vienna, Austria
| | - Dinshaw J Patel
- Structural Biology Program, Memorial Sloan Kettering Cancer Center, New York, New York 10065, USA
| | - Julius Brennecke
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), 1030 Vienna, Austria
| |
Collapse
|
39
|
Eastwood EL, Jara KA, Bornelöv S, Munafò M, Frantzis V, Kneuss E, Barbar EJ, Czech B, Hannon GJ. Dimerisation of the PICTS complex via LC8/Cut-up drives co-transcriptional transposon silencing in Drosophila. eLife 2021; 10:e65557. [PMID: 33538693 PMCID: PMC7861614 DOI: 10.7554/elife.65557] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Accepted: 01/04/2021] [Indexed: 12/16/2022] Open
Abstract
In animal gonads, the PIWI-interacting RNA (piRNA) pathway guards genome integrity in part through the co-transcriptional gene silencing of transposon insertions. In Drosophila ovaries, piRNA-loaded Piwi detects nascent transposon transcripts and instructs heterochromatin formation through the Panoramix-induced co-transcriptional silencing (PICTS) complex, containing Panoramix, Nxf2 and Nxt1. Here, we report that the highly conserved dynein light chain LC8/Cut-up (Ctp) is an essential component of the PICTS complex. Loss of Ctp results in transposon de-repression and a reduction in repressive chromatin marks specifically at transposon loci. In turn, Ctp can enforce transcriptional silencing when artificially recruited to RNA and DNA reporters. We show that Ctp drives dimerisation of the PICTS complex through its interaction with conserved motifs within Panoramix. Artificial dimerisation of Panoramix bypasses the necessity for its interaction with Ctp, demonstrating that conscription of a protein from a ubiquitous cellular machinery has fulfilled a fundamental requirement for a transposon silencing complex.
Collapse
Affiliation(s)
- Evelyn L Eastwood
- Cancer Research UK Cambridge Institute, University of Cambridge, Li Ka Shing CentreCambridgeUnited Kingdom
| | - Kayla A Jara
- Department of Biochemistry and Biophysics, Oregon State UniversityCorvallisUnited States
| | - Susanne Bornelöv
- Cancer Research UK Cambridge Institute, University of Cambridge, Li Ka Shing CentreCambridgeUnited Kingdom
| | - Marzia Munafò
- Cancer Research UK Cambridge Institute, University of Cambridge, Li Ka Shing CentreCambridgeUnited Kingdom
| | - Vasileios Frantzis
- Cancer Research UK Cambridge Institute, University of Cambridge, Li Ka Shing CentreCambridgeUnited Kingdom
| | - Emma Kneuss
- Cancer Research UK Cambridge Institute, University of Cambridge, Li Ka Shing CentreCambridgeUnited Kingdom
| | - Elisar J Barbar
- Department of Biochemistry and Biophysics, Oregon State UniversityCorvallisUnited States
| | - Benjamin Czech
- Cancer Research UK Cambridge Institute, University of Cambridge, Li Ka Shing CentreCambridgeUnited Kingdom
| | - Gregory J Hannon
- Cancer Research UK Cambridge Institute, University of Cambridge, Li Ka Shing CentreCambridgeUnited Kingdom
| |
Collapse
|
40
|
Kalashnikova DA, Maksimov DA, Romanov SE, Laktionov PP, Koryakov DE. SetDB1 and Su(var)3-9 play non-overlapping roles in somatic cell chromosomes of Drosophila melanogaster. J Cell Sci 2021; 134:jcs.253096. [PMID: 33288549 DOI: 10.1242/jcs.253096] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 11/30/2020] [Indexed: 11/20/2022] Open
Abstract
We explored functional roles of two H3K9-specific histone methyltransferases of Drosophila melanogaster, SetDB1 (also known as Eggless) and Su(var)3-9. Using the DamID approach, we generated the binding profile for SetDB1 in Drosophila salivary gland chromosomes, and matched it to the profile of Su(var)3-9. Unlike Su(var)3-9, SetDB1 turned out to be an euchromatic protein that is absent from repeated DNA compartments, and is largely restricted to transcription start sites (TSSs) and 5' untranslated regions (5'UTRs) of ubiquitously expressed genes. Significant SetDB1 association is also observed at binding sites for the insulator protein CP190. SetDB1 and H3K9 di- and tri-methylated (me2 and me3)-enriched sites tend to display poor overlap. At the same time, SetDB1 has a clear connection with the distribution of H3K27me3 mark. SetDB1 binds outside the domains possessing this modification, and about half of the borders of H3K27me3 domains are decorated by SetDB1 together with actively transcribed genes. On the basis of poor correlation between the distribution of SetDB1 and H3K9 methylation marks, we speculate that, in somatic cells, SetDB1 may contribute to the methylation of a broader set of chromosomal proteins than just H3K9. In addition, SetDB1 can be expected to play a role in the establishment of chromatin functional domains.
Collapse
Affiliation(s)
| | - Daniil A Maksimov
- Institute of Molecular and Cellular Biology, Novosibirsk 630090, Russia
| | - Stanislav E Romanov
- Institute of Molecular and Cellular Biology, Novosibirsk 630090, Russia.,Laboratory of Epigenetics, Department of Natural Sciences, Novosibirsk State University, Novosibirsk 630090, Russia
| | - Petr P Laktionov
- Institute of Molecular and Cellular Biology, Novosibirsk 630090, Russia.,Laboratory of Epigenetics, Department of Natural Sciences, Novosibirsk State University, Novosibirsk 630090, Russia
| | - Dmitry E Koryakov
- Institute of Molecular and Cellular Biology, Novosibirsk 630090, Russia
| |
Collapse
|
41
|
Wang C, Lin H. Roles of piRNAs in transposon and pseudogene regulation of germline mRNAs and lncRNAs. Genome Biol 2021; 22:27. [PMID: 33419460 PMCID: PMC7792047 DOI: 10.1186/s13059-020-02221-x] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 12/07/2020] [Indexed: 12/28/2022] Open
Abstract
PIWI proteins, a subfamily of PAZ/PIWI Domain family RNA-binding proteins, are best known for their function in silencing transposons and germline development by partnering with small noncoding RNAs called PIWI-interacting RNAs (piRNAs). However, recent studies have revealed multifaceted roles of the PIWI-piRNA pathway in regulating the expression of other major classes of RNAs in germ cells. In this review, we summarize how PIWI proteins and piRNAs regulate the expression of many disparate RNAs, describing a highly complex global genomic regulatory relationship at the RNA level through which piRNAs functionally connect all major constituents of the genome in the germline.
Collapse
Affiliation(s)
- Chen Wang
- Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech University, Shanghai, 201210, China
| | - Haifan Lin
- Yale Stem Cell Center and Department of Cell Biology, Yale University School of Medicine, New Haven, CT, 06519, USA.
| |
Collapse
|
42
|
Lauria Sneideman MP, Meller VH. Drosophila Satellite Repeats at the Intersection of Chromatin, Gene Regulation and Evolution. PROGRESS IN MOLECULAR AND SUBCELLULAR BIOLOGY 2021; 60:1-26. [PMID: 34386870 DOI: 10.1007/978-3-030-74889-0_1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Satellite repeats make up a large fraction of the genomes of many higher eukaryotes. Until recently these sequences were viewed as molecular parasites with few functions. Drosophila melanogaster and related species have a wealth of diverse satellite repeats. Comparative studies of Drosophilids have been instrumental in understanding how these rapidly evolving sequences change and move. Remarkably, satellite repeats have been found to modulate gene expression and mediate genetic conflicts between chromosomes and between closely related fly species. This suggests that satellites play a key role in speciation. We have taken advantage of the depth of research on satellite repeats in flies to review the known functions of these sequences and consider their central role in evolution and gene expression.
Collapse
Affiliation(s)
| | - Victoria H Meller
- Department of Biological Sciences, Wayne State University, Detroit, MI, USA.
| |
Collapse
|
43
|
Wu SK, Roberts JT, Balas MM, Johnson AM. RNA matchmaking in chromatin regulation. Biochem Soc Trans 2020; 48:2467-2481. [PMID: 33245317 PMCID: PMC7888525 DOI: 10.1042/bst20191225] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Revised: 10/05/2020] [Accepted: 10/07/2020] [Indexed: 01/12/2023]
Abstract
Beyond being the product of gene expression, RNA can also influence the regulation of chromatin. The majority of the human genome has the capacity to be transcribed and the majority of the non-protein-coding transcripts made by RNA Polymerase II are enriched in the nucleus. Many chromatin regulators can bind to these ncRNAs in the nucleus; in some cases, there are clear examples of direct RNA-mediated chromatin regulation mechanisms stemming from these interactions, while others have yet to be determined. Recent studies have highlighted examples of chromatin regulation via RNA matchmaking, a term we use broadly here to describe intermolecular base-pairing interactions between one RNA molecule and an RNA or DNA match. This review provides examples of RNA matchmaking that regulates chromatin processes and summarizes the technical approaches used to capture these events.
Collapse
Affiliation(s)
- Stephen K. Wu
- Molecular Biology Program, University of Colorado Denver Anschutz Medical Campus 12801 East 17 Ave., Aurora, CO, United States
- Department of Biochemistry and Molecular Genetics, University of Colorado Denver Anschutz Medical Campus 12801 East 17 Ave., Aurora, CO, United States
| | - Justin T. Roberts
- Molecular Biology Program, University of Colorado Denver Anschutz Medical Campus 12801 East 17 Ave., Aurora, CO, United States
- Department of Biochemistry and Molecular Genetics, University of Colorado Denver Anschutz Medical Campus 12801 East 17 Ave., Aurora, CO, United States
| | - Maggie M. Balas
- Molecular Biology Program, University of Colorado Denver Anschutz Medical Campus 12801 East 17 Ave., Aurora, CO, United States
- Department of Biochemistry and Molecular Genetics, University of Colorado Denver Anschutz Medical Campus 12801 East 17 Ave., Aurora, CO, United States
| | - Aaron M. Johnson
- Molecular Biology Program, University of Colorado Denver Anschutz Medical Campus 12801 East 17 Ave., Aurora, CO, United States
- Department of Biochemistry and Molecular Genetics, University of Colorado Denver Anschutz Medical Campus 12801 East 17 Ave., Aurora, CO, United States
| |
Collapse
|
44
|
Onishi R, Sato K, Murano K, Negishi L, Siomi H, Siomi MC. Piwi suppresses transcription of Brahma-dependent transposons via Maelstrom in ovarian somatic cells. SCIENCE ADVANCES 2020; 6:6/50/eaaz7420. [PMID: 33310860 PMCID: PMC7732180 DOI: 10.1126/sciadv.aaz7420] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2019] [Accepted: 10/19/2020] [Indexed: 05/05/2023]
Abstract
Drosophila Piwi associates with PIWI-interacting RNAs (piRNAs) and represses transposons transcriptionally through heterochromatinization; however, this process is poorly understood. Here, we identify Brahma (Brm), the core adenosine triphosphatase of the SWI/SNF chromatin remodeling complex, as a new Piwi interactor, and show Brm involvement in activating transcription of Piwi-targeted transposons before silencing. Bioinformatic analyses indicated that Piwi, once bound to target RNAs, reduced the occupancies of SWI/SNF and RNA polymerase II (Pol II) on target loci, abrogating transcription. Artificial piRNA-driven targeting of Piwi to RNA transcripts enhanced repression of Brm-dependent reporters compared with Brm-independent reporters. This was dependent on Piwi cofactors, Gtsf1/Asterix (Gtsf1), Panoramix/Silencio (Panx), and Maelstrom (Mael), but not Eggless/dSetdb (Egg)-mediated H3K9me3 deposition. The λN-box B-mediated tethering of Mael to reporters repressed Brm-dependent genes in the absence of Piwi, Panx, and Gtsf1. We propose that Piwi, via Mael, can rapidly suppress transcription of Brm-dependent genes to facilitate heterochromatin formation.
Collapse
Affiliation(s)
- Ryo Onishi
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo 113-0032, Japan
| | - Kaoru Sato
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo 113-0032, Japan
| | - Kensaku Murano
- Department of Molecular Biology, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Lumi Negishi
- Central Laboratory, Institute for Quantitative Biosciences, The University of Tokyo, Tokyo 113-0032, Japan
| | - Haruhiko Siomi
- Department of Molecular Biology, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Mikiko C Siomi
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo 113-0032, Japan.
| |
Collapse
|
45
|
Luo Y, Fefelova E, Ninova M, Chen YCA, Aravin AA. Repression of interrupted and intact rDNA by the SUMO pathway in Drosophila melanogaster. eLife 2020; 9:e52416. [PMID: 33164748 PMCID: PMC7676866 DOI: 10.7554/elife.52416] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Accepted: 11/06/2020] [Indexed: 11/17/2022] Open
Abstract
Ribosomal RNAs (rRNAs) are essential components of the ribosome and are among the most abundant macromolecules in the cell. To ensure high rRNA level, eukaryotic genomes contain dozens to hundreds of rDNA genes, however, only a fraction of the rRNA genes seems to be active, while others are transcriptionally silent. We found that individual rDNA genes have high level of cell-to-cell heterogeneity in their expression in Drosophila melanogaster. Insertion of heterologous sequences into rDNA leads to repression associated with reduced expression in individual cells and decreased number of cells expressing rDNA with insertions. We found that SUMO (Small Ubiquitin-like Modifier) and SUMO ligase Ubc9 are required for efficient repression of interrupted rDNA units and variable expression of intact rDNA. Disruption of the SUMO pathway abolishes discrimination of interrupted and intact rDNAs and removes cell-to-cell heterogeneity leading to uniformly high expression of individual rDNA in single cells. Our results suggest that the SUMO pathway is responsible for both repression of interrupted units and control of intact rDNA expression.
Collapse
Affiliation(s)
- Yicheng Luo
- Division of Biology and Biological Engineering, California Institute of TechnologyPasadenaUnited States
| | - Elena Fefelova
- Division of Biology and Biological Engineering, California Institute of TechnologyPasadenaUnited States
- Institute of Molecular Genetics, Russian Academy of SciencesMoscowRussian Federation
| | - Maria Ninova
- Division of Biology and Biological Engineering, California Institute of TechnologyPasadenaUnited States
| | - Yung-Chia Ariel Chen
- Division of Biology and Biological Engineering, California Institute of TechnologyPasadenaUnited States
| | - Alexei A Aravin
- Division of Biology and Biological Engineering, California Institute of TechnologyPasadenaUnited States
| |
Collapse
|
46
|
Piwi-interacting RNAs (piRNAs) as potential biomarkers and therapeutic targets for cardiovascular diseases. Angiogenesis 2020; 24:19-34. [PMID: 33011960 DOI: 10.1007/s10456-020-09750-w] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2020] [Revised: 07/09/2020] [Accepted: 09/24/2020] [Indexed: 12/24/2022]
Abstract
Cardiovascular diseases (CVDs) are the leading causes of death worldwide. Increasing reports demonstrated that non-coding RNAs (ncRNAs) have been crucially involved in the development of CVDs. Piwi-interacting RNAs (piRNAs) are a novel cluster of small non-coding RNAs with strong uracil bias at the 5' end and 2'-O-methylation at the 3' end that are mainly present in the mammalian reproductive system and stem cells and serve as potential modulators of developmental and pathophysiological processes. Recently, piRNAs have been reported to be widely expressed in human tissues and can potentially regulate various diseases. Specifically, concomitant with the development of next-generation sequencing techniques, piRNAs have been found to be differentially expressed in CVDs, indicating their potential involvement in the occurrence and progression of heart diseases. However, the molecular mechanisms and signaling pathways involved with piRNA function have not been fully elucidated. In this review, we present the current understanding of the piRNAs from the perspectives of biogenesis, characteristics, biological function, and regulatory mechanisms, and highlight their potential roles and underlying mechanisms in CVDs, which will provide new insights into the potential applications of piRNAs in the clinical diagnosis, prognosis, and therapeutic strategies for heart diseases.
Collapse
|
47
|
Jing Z, Xi Y, Yin J, Shuwen H. Biological roles of piRNAs in colorectal cancer. Gene 2020; 769:145063. [PMID: 32827685 DOI: 10.1016/j.gene.2020.145063] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Accepted: 08/17/2020] [Indexed: 12/25/2022]
Abstract
Colorectal cancer (CRC) is one of the most common malignancies worldwide and a major cause of cancer-related deaths. Numerous studies have suggested that piwi-interacting RNAs (piRNAs), a new type of non-coding RNA (ncRNA), are closely related to the occurrence and development of cancer. piRNAs have been shown to regulate the occurrence of CRC by modulating multiple molecular signaling pathways. Here, the roles of piRNAs in CRC were reviewed to provide evidence for their potential as molecular targets for CRC.
Collapse
Affiliation(s)
- Zhuang Jing
- Graduate School of Nursing, Huzhou University, Zhejiang, No. 1 Bachelor Road, Huzhou, Zhejiang Province 313000, PR China
| | - Yang Xi
- Department of Oncology, Huzhou Cent Hospital, Affiliated Cent Hospital HuZhou University, 198 Hongqi Rd, Huzhou, Zhejiang 313000, PR China
| | - Jin Yin
- Department of Laboratory Medicine, Huzhou Cent Hospital, Affiliated Cent Hospital HuZhou University, 198 Hongqi Rd, Huzhou, Zhejiang 313000, PR China
| | - Han Shuwen
- Department of Oncology, Huzhou Cent Hospital, Affiliated Cent Hospital HuZhou University, 198 Hongqi Rd, Huzhou, Zhejiang 313000, PR China.
| |
Collapse
|
48
|
Choi JY, Lee YCG. Double-edged sword: The evolutionary consequences of the epigenetic silencing of transposable elements. PLoS Genet 2020; 16:e1008872. [PMID: 32673310 PMCID: PMC7365398 DOI: 10.1371/journal.pgen.1008872] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Transposable elements (TEs) are genomic parasites that selfishly replicate at the expense of host fitness. Fifty years of evolutionary studies of TEs have concentrated on the deleterious genetic effects of TEs, such as their effects on disrupting genes and regulatory sequences. However, a flurry of recent work suggests that there is another important source of TEs' harmful effects-epigenetic silencing. Host genomes typically silence TEs by the deposition of repressive epigenetic marks. While this silencing reduces the selfish replication of TEs and should benefit hosts, a picture is emerging that the epigenetic silencing of TEs triggers inadvertent spreading of repressive marks to otherwise expressed neighboring genes, ultimately jeopardizing host fitness. In this Review, we provide a long-overdue overview of the recent genome-wide evidence for the presence and prevalence of TEs' epigenetic effects, highlighting both the similarities and differences across mammals, insects, and plants. We lay out the current understanding of the functional and fitness consequences of TEs' epigenetic effects, and propose possible influences of such effects on the evolution of both hosts and TEs themselves. These unique evolutionary consequences indicate that TEs' epigenetic effect is not only a crucial component of TE biology but could also be a significant contributor to genome function and evolution.
Collapse
Affiliation(s)
- Jae Young Choi
- Center for Genomics and Systems Biology, Department of Biology, New York University, New York, New York State, United States of America
| | - Yuh Chwen G. Lee
- Department of Ecology and Evolutionary Biology, University of California, Irvine, California, United States of America
| |
Collapse
|
49
|
Cacchione S, Cenci G, Raffa GD. Silence at the End: How Drosophila Regulates Expression and Transposition of Telomeric Retroelements. J Mol Biol 2020; 432:4305-4321. [PMID: 32512004 DOI: 10.1016/j.jmb.2020.06.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 05/25/2020] [Accepted: 06/02/2020] [Indexed: 01/26/2023]
Abstract
The maintenance of chromosome ends in Drosophila is an exceptional phenomenon because it relies on the transposition of specialized retrotransposons rather than on the activity of the enzyme telomerase that maintains telomeres in almost every other eukaryotic species. Sequential transpositions of Het-A, TART, and TAHRE (HTT) onto chromosome ends produce long head-to-tail arrays that are reminiscent to the long arrays of short repeats produced by telomerase in other organisms. Coordinating the activation and silencing of the HTT array with the recruitment of telomere capping proteins favors proper telomere function. However, how this coordination is achieved is not well understood. Like other Drosophila retrotransposons, telomeric elements are regulated by the piRNA pathway. Remarkably, HTT arrays are both source of piRNA and targets of gene silencing thus making the regulation of Drosophila telomeric transposons a unique event among eukaryotes. Herein we will review the genetic and molecular mechanisms underlying the regulation of HTT transcription and transposition and will discuss the possibility of a crosstalk between piRNA-mediated regulation, telomeric chromatin establishment, and telomere protection.
Collapse
Affiliation(s)
- Stefano Cacchione
- Department of Biology and Biotechnology, Sapienza University of Rome, P.le Aldo Moro 5, 00185 Roma, Italy.
| | - Giovanni Cenci
- Department of Biology and Biotechnology, Sapienza University of Rome, P.le Aldo Moro 5, 00185 Roma, Italy; Fondazione Cenci Bolognetti, Istituto Pasteur, Rome, Italy.
| | - Grazia Daniela Raffa
- Department of Biology and Biotechnology, Sapienza University of Rome, P.le Aldo Moro 5, 00185 Roma, Italy.
| |
Collapse
|
50
|
Ilyin AA, Stolyarenko AD, Klenov MS, Shevelyov YY. Various modes of HP1a interactions with the euchromatic chromosome arms in Drosophila ovarian somatic cells. Chromosoma 2020; 129:201-214. [PMID: 32500264 DOI: 10.1007/s00412-020-00738-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Revised: 05/05/2020] [Accepted: 05/26/2020] [Indexed: 12/20/2022]
Abstract
Heterochromatin protein 1a (HP1a) is a well-known component of pericentromeric and telomeric heterochromatin in Drosophila. However, its role and the mechanisms of its binding in the chromosome arms (ChAs) remain largely unclear. Here, we identified HP1a-interacting domains in the somatic cells of Drosophila ovaries using a DamID-seq approach and compared them with insertion sites of transposable elements (TEs) revealed by genome sequencing. Although HP1a domains cover only 13% of ChAs, they non-randomly associate with 42% of TE insertions. Furthermore, HP1a on average propagates at 2-kb distances from the TE insertions. These data confirm the role of TEs in formation of HP1a islands in ChAs. However, only 18% of HP1a domains have adjacent TEs, indicating the existence of other mechanisms of HP1a domain formation besides spreading from TEs. In particular, many TE-independent HP1a domains correspond to the regions attached to the nuclear pore complexes (NPCs) or contain active gene promoters. However, HP1a occupancy on the promoters does not significantly influence expression of corresponding genes. At the same time, the steady-state transcript level of many genes located outside of HP1a domains was altered upon HP1a knockdown in the somatic cells of ovaries, thus pointing to the strong indirect effect of HP1a depletion. Collectively, our results support an existence of at least three different mechanisms of HP1a domain emergence in ChAs: spreading from TE insertions, transient interactions with the chromatin located near NPCs, and targeting to the promoters of moderately expressed genes.
Collapse
Affiliation(s)
- Artem A Ilyin
- Department of Molecular Genetics of Cell, Institute of Molecular Genetics, Russian Academy of Sciences, Kurchatov Sq. 2, Moscow, Russia, 123182
| | - Anastasia D Stolyarenko
- Department of Molecular Genetics of Cell, Institute of Molecular Genetics, Russian Academy of Sciences, Kurchatov Sq. 2, Moscow, Russia, 123182
| | - Mikhail S Klenov
- Department of Molecular Genetics of Cell, Institute of Molecular Genetics, Russian Academy of Sciences, Kurchatov Sq. 2, Moscow, Russia, 123182.
| | - Yuri Y Shevelyov
- Department of Molecular Genetics of Cell, Institute of Molecular Genetics, Russian Academy of Sciences, Kurchatov Sq. 2, Moscow, Russia, 123182.
| |
Collapse
|