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Vignolini T, Couble JEC, Doré GRG, Baumgarten S. Transcript tinkering: RNA modifications in protozoan parasites. Curr Opin Microbiol 2024; 79:102477. [PMID: 38663181 DOI: 10.1016/j.mib.2024.102477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 03/19/2024] [Accepted: 04/03/2024] [Indexed: 06/11/2024]
Abstract
Apicomplexan and trypanosomatid parasites have evolved a wide range of post-transcriptional processes that allow them to replicate, differentiate, and transmit within and among multiple different tissue, host, and vector environments. In this review, we highlight the recent advances that point toward the regulatory potential of RNA modifications in mediating these processes on the coding and noncoding transcriptome throughout the life cycle of protozoan parasites. We discuss the recent technical advancements enabling the study of the 'epitranscriptome' and how parasites evolved RNA modification-mediated mechanisms adapted to their unique lifestyles.
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Affiliation(s)
- Tiziano Vignolini
- Institut Pasteur, Université Paris Cité, G5 Parasite RNA Biology, Department of Parasites and Insect Vectors, F-75015 Paris, France
| | - Justine E C Couble
- Institut Pasteur, Université Paris Cité, G5 Parasite RNA Biology, Department of Parasites and Insect Vectors, F-75015 Paris, France
| | - Grégory R G Doré
- Institut Pasteur, Université Paris Cité, G5 Parasite RNA Biology, Department of Parasites and Insect Vectors, F-75015 Paris, France
| | - Sebastian Baumgarten
- Institut Pasteur, Université Paris Cité, G5 Parasite RNA Biology, Department of Parasites and Insect Vectors, F-75015 Paris, France.
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2
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Guo G, Lin Y, Zhu X, Ding F, Xue X, Zhang Q. Emerging roles of the epitranscriptome in parasitic protozoan biology and pathogenesis. Trends Parasitol 2024; 40:214-229. [PMID: 38355313 DOI: 10.1016/j.pt.2024.01.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2023] [Revised: 01/16/2024] [Accepted: 01/17/2024] [Indexed: 02/16/2024]
Abstract
RNA modifications (epitranscriptome) - such as N6-methyladenosine (m6A), 5-methylcytosine (m5C), and pseudouridine (Ψ) - modulate RNA processing, stability, interaction, and translation, thereby playing critical roles in the development, replication, virulence, metabolism, and life cycle adaptations of parasitic protozoa. Here, we summarize potential homologs of the major human RNA modification regulatory factors in parasites, outline current knowledge on how RNA modifications affect parasitic protozoa, highlight the regulation of RNA modifications and their crosstalk, and discuss current progress in exploring RNA modifications as potential drug targets. This review contributes to our understanding of epitranscriptomic regulation of parasitic protozoa biology and pathogenesis and provides new perspectives for the treatment of parasitic diseases.
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Affiliation(s)
- Gangqiang Guo
- Wenzhou Collaborative Innovation Center of Gastrointestinal Cancer in Basic Research and Precision Medicine, Wenzhou Key Laboratory of Cancer-related Pathogens and Immunity, Department of Microbiology and Immunology, Institute of Molecular Virology and Immunology, Institute of Tropical Medicine, School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou, China
| | - Yutong Lin
- First Clinical College, Wenzhou Medical University, Wenzhou, China
| | - Xinqi Zhu
- First Clinical College, Wenzhou Medical University, Wenzhou, China
| | - Feng Ding
- Department of Microbiology and Immunology, School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou, China
| | - Xiangyang Xue
- Wenzhou Collaborative Innovation Center of Gastrointestinal Cancer in Basic Research and Precision Medicine, Wenzhou Key Laboratory of Cancer-related Pathogens and Immunity, Department of Microbiology and Immunology, Institute of Molecular Virology and Immunology, Institute of Tropical Medicine, School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou, China.
| | - Qingfeng Zhang
- Laboratory of Molecular Parasitology, State Key Laboratory of Cardiology and Research Center for Translational Medicine, Shanghai East Hospital; Clinical Center for Brain and Spinal Cord Research, School of Medicine, Tongji University, Shanghai 200120, China.
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3
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Govindaraju G, Rajavelu A. Reading the epitranscriptome of the human malaria parasite. Biomed J 2024:100703. [PMID: 38316392 DOI: 10.1016/j.bj.2024.100703] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 01/30/2024] [Accepted: 02/01/2024] [Indexed: 02/07/2024] Open
Abstract
Epigenetic machinery has emerged as a central player in gene regulation and chromatin organization in Plasmodium spp. Epigenetic modifications on histones and their role in antigenic variation in P. falciparum are widely studied. Recent discoveries on nucleic acid methylome are exciting and provide a new dimension to the apicomplexan protozoan parasite's gene regulatory process. Reports have confirmed that N6-methyl adenosine (m6A) methylation plays a crucial role in the translational plasticity of the human malaria parasite during its development in RBC. The YTH domain (YT521-B Homology) protein in P. falciparum binds to m6A epitranscriptome modifications on the mRNA and regulates protein translation. The binding of the PfYTH domain protein to the m6A-modified mRNA is mediated through a binding pocket formed by aromatic amino acids. The P. falciparum genome encodes two members of YTH domain proteins, i.e., YTH1 and YTH2, and both have distinct roles in dictating the epitranscriptome in human malaria parasites. This review highlights recent advancements in the functions and mechanisms of YTH domain protein's role in translational plasticity in the various developmental stages of the parasite.
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Affiliation(s)
- Gayathri Govindaraju
- Department of Biotechnology, Bhupat & Jyoti Mehta School of Biosciences, Indian Institute of Technology, Chennai, India
| | - Arumugam Rajavelu
- Department of Biotechnology, Bhupat & Jyoti Mehta School of Biosciences, Indian Institute of Technology, Chennai, India.
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Kioko M, Pance A, Mwangi S, Goulding D, Kemp A, Rono M, Ochola-Oyier LI, Bull PC, Bejon P, Rayner JC, Abdi AI. Extracellular vesicles could be a putative posttranscriptional regulatory mechanism that shapes intracellular RNA levels in Plasmodium falciparum. Nat Commun 2023; 14:6447. [PMID: 37833314 PMCID: PMC10575976 DOI: 10.1038/s41467-023-42103-x] [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: 10/28/2022] [Accepted: 09/26/2023] [Indexed: 10/15/2023] Open
Abstract
Plasmodium falciparum secretes extracellular vesicles (PfEVs) that contain parasite-derived RNA. However, the significance of the secreted RNA remains unexplored. Here, we compare secreted and intracellular RNA from asexual cultures of six P. falciparum lines. We find that secretion of RNA via extracellular vesicles is not only periodic throughout the asexual intraerythrocytic developmental cycle but is also highly conserved across P. falciparum isolates. We further demonstrate that the phases of RNA secreted via extracellular vesicles are discernibly shifted compared to those of the intracellular RNA within the secreting whole parasite. Finally, transcripts of genes with no known function during the asexual intraerythrocytic developmental cycle are enriched in PfEVs compared to the whole parasite. We conclude that the secretion of extracellular vesicles could be a putative posttranscriptional RNA regulation mechanism that is part of or synergise the classic RNA decay processes to maintain intracellular RNA levels in P. falciparum.
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Affiliation(s)
- Mwikali Kioko
- Bioscience Department, KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
- Open University, Milton Keynes, UK
| | - Alena Pance
- Pathogens and Microbes Programme, Wellcome Sanger Institute, Cambridge, UK
- School of Life and Medical Science, University of Hertfordshire, Hatfield, UK
| | - Shaban Mwangi
- Bioscience Department, KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
| | - David Goulding
- Pathogens and Microbes Programme, Wellcome Sanger Institute, Cambridge, UK
| | - Alison Kemp
- Cambridge Institute of Medical Research, University of Cambridge, Cambridge, UK
| | - Martin Rono
- Bioscience Department, KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
- Pwani University Biosciences Research Centre, Pwani University, Kilifi, Kenya
| | | | - Pete C Bull
- Bioscience Department, KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Philip Bejon
- Bioscience Department, KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Julian C Rayner
- Cambridge Institute of Medical Research, University of Cambridge, Cambridge, UK
| | - Abdirahman I Abdi
- Bioscience Department, KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya.
- Pwani University Biosciences Research Centre, Pwani University, Kilifi, Kenya.
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
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Swale C, Hakimi MA. 3'-end mRNA processing within apicomplexan parasites, a patchwork of classic, and unexpected players. WILEY INTERDISCIPLINARY REVIEWS. RNA 2023; 14:e1783. [PMID: 36994829 DOI: 10.1002/wrna.1783] [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: 08/25/2022] [Revised: 01/17/2023] [Accepted: 01/25/2023] [Indexed: 03/31/2023]
Abstract
The 3'-end processing of mRNA is a co-transcriptional process that leads to the formation of a poly-adenosine tail on the mRNA and directly controls termination of the RNA polymerase II juggernaut. This process involves a megadalton complex composed of cleavage and polyadenylation specificity factors (CPSFs) that are able to recognize cis-sequence elements on nascent mRNA to then carry out cleavage and polyadenylation reactions. Recent structural and biochemical studies have defined the roles played by different subunits of the complex and provided a comprehensive mechanistic understanding of this machinery in yeast or metazoans. More recently, the discovery of small molecule inhibitors of CPSF function in Apicomplexa has stimulated interest in studying the specificities of this ancient eukaryotic machinery in these organisms. Although its function is conserved in Apicomplexa, the CPSF complex integrates a novel reader of the N6-methyladenosine (m6A). This feature, inherited from the plant kingdom, bridges m6A metabolism directly to 3'-end processing and by extension, to transcription termination. In this review, we will examine convergence and divergence of CPSF within the apicomplexan parasites and explore the potential of small molecule inhibition of this machinery within these organisms. This article is categorized under: RNA Processing > 3' End Processing RNA Processing > RNA Editing and Modification.
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Affiliation(s)
- Christopher Swale
- Team Host-Pathogen Interactions and Immunity to Infection, Institute for Advanced Biosciences, INSERM U1209, CNRS UMR5309, Grenoble Alpes University, Grenoble, France
| | - Mohamed-Ali Hakimi
- Team Host-Pathogen Interactions and Immunity to Infection, Institute for Advanced Biosciences, INSERM U1209, CNRS UMR5309, Grenoble Alpes University, Grenoble, France
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Martinez De La Cruz B, Darsinou M, Riccio A. From form to function: m 6A methylation links mRNA structure to metabolism. Adv Biol Regul 2023; 87:100926. [PMID: 36513580 PMCID: PMC10585597 DOI: 10.1016/j.jbior.2022.100926] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Revised: 10/17/2022] [Accepted: 11/03/2022] [Indexed: 11/19/2022]
Abstract
Reversible N6-methyladenosine (m6A) RNA modification is a posttranscriptional epigenetic modification of the RNA that regulates many key aspects of RNA metabolism and function. In this review, we highlight major recent advances in the field, with special emphasis on the potential link between m6A modifications and RNA structure. We will also discuss the role of RNA methylation of neuronal transcripts, and the emerging evidence of a potential role in RNA transport and local translation in dendrites and axons of transcripts involved in synaptic functions and axon growth.
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Affiliation(s)
| | - Marousa Darsinou
- UCL Laboratory for Molecular Cell Biology - University College London, Gower Street, WC1E 6BT, London, UK
| | - Antonella Riccio
- UCL Laboratory for Molecular Cell Biology - University College London, Gower Street, WC1E 6BT, London, UK.
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Catacalos C, Krohannon A, Somalraju S, Meyer KD, Janga SC, Chakrabarti K. Epitranscriptomics in parasitic protists: Role of RNA chemical modifications in posttranscriptional gene regulation. PLoS Pathog 2022; 18:e1010972. [PMID: 36548245 PMCID: PMC9778586 DOI: 10.1371/journal.ppat.1010972] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
"Epitranscriptomics" is the new RNA code that represents an ensemble of posttranscriptional RNA chemical modifications, which can precisely coordinate gene expression and biological processes. There are several RNA base modifications, such as N6-methyladenosine (m6A), 5-methylcytosine (m5C), and pseudouridine (Ψ), etc. that play pivotal roles in fine-tuning gene expression in almost all eukaryotes and emerging evidences suggest that parasitic protists are no exception. In this review, we primarily focus on m6A, which is the most abundant epitranscriptomic mark and regulates numerous cellular processes, ranging from nuclear export, mRNA splicing, polyadenylation, stability, and translation. We highlight the universal features of spatiotemporal m6A RNA modifications in eukaryotic phylogeny, their homologs, and unique processes in 3 unicellular parasites-Plasmodium sp., Toxoplasma sp., and Trypanosoma sp. and some technological advances in this rapidly developing research area that can significantly improve our understandings of gene expression regulation in parasites.
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Affiliation(s)
- Cassandra Catacalos
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, North Carolina, United States of America
| | - Alexander Krohannon
- Department of BioHealth Informatics, School of Informatics and Computing, Indiana University Purdue University Indianapolis (IUPUI), Indianapolis, Indiana, United States of America
| | - Sahiti Somalraju
- Department of BioHealth Informatics, School of Informatics and Computing, Indiana University Purdue University Indianapolis (IUPUI), Indianapolis, Indiana, United States of America
| | - Kate D. Meyer
- Department of Biochemistry, Duke University School of Medicine, Durham, North Carolina, United States of America
| | - Sarath Chandra Janga
- Department of BioHealth Informatics, School of Informatics and Computing, Indiana University Purdue University Indianapolis (IUPUI), Indianapolis, Indiana, United States of America
| | - Kausik Chakrabarti
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, North Carolina, United States of America
- * E-mail:
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Wang L, Wu J, Liu R, Chen W, Pang Z, Zhou F, Xia L, Huang J, Pan T, Su XZ, Wang X. Epitranscriptome profiling of spleen mRNA m 6A methylation reveals pathways of host responses to malaria parasite infection. Front Immunol 2022; 13:998756. [PMID: 36203583 PMCID: PMC9531237 DOI: 10.3389/fimmu.2022.998756] [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: 07/20/2022] [Accepted: 09/05/2022] [Indexed: 11/29/2022] Open
Abstract
N6 -Methyladenosine (m6A), the most abundant mammalian mRNA modification, has been reported to modulate various viral infections. Although it has been confirmed that RNA modifications can also modulate the replication and development of different parasites, the role of the RNA epitranscriptome in the regulation of host response post parasite infection remains to be elucidated. Here we report host spleen m6A epitranscriptome landscapes induced by different strains of the malaria parasite Plasmodium yoelii. We found that malaria parasite infection dramatically changes host spleen m6A mRNA modification and gene expression. Additionally, malaria parasite infection reprograms host immune response pathways by regulating the m6A modification enzymes. Collectively, our study is the first characterization of host spleen m6A methylome triggered by malaria parasite infections, and our data identify m6A modifications as significant transcriptome-wide marks during host-parasite interactions. We demonstrate that host mRNA methylation machinery can sense and respond to malaria parasite infections, and provide new insights into epitranscriptomic mechanisms underlying parasite-induced pathogenesis.
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Affiliation(s)
- Luoluo Wang
- School of Life Sciences, South China Normal University, Guangzhou, China
| | - Jian Wu
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, United States
| | - Runzhou Liu
- School of Life Sciences, South China Normal University, Guangzhou, China
| | - Wenjun Chen
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, IL, United States
| | - Zhichang Pang
- School of Life Sciences, South China Normal University, Guangzhou, China
| | - Fan Zhou
- School of Life Sciences, South China Normal University, Guangzhou, China
| | - Lu Xia
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, United States
- Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, China
| | - Jia Huang
- School of Life Sciences, South China Normal University, Guangzhou, China
| | - Tao Pan
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL, United States
| | - Xin-zhuan Su
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, United States
| | - Xiaoyun Wang
- School of Life Sciences, South China Normal University, Guangzhou, China
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Wunderlich J. Updated List of Transport Proteins in Plasmodium falciparum. Front Cell Infect Microbiol 2022; 12:926541. [PMID: 35811673 PMCID: PMC9263188 DOI: 10.3389/fcimb.2022.926541] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 05/23/2022] [Indexed: 11/13/2022] Open
Abstract
Malaria remains a leading cause of death and disease in many tropical and subtropical regions of the world. Due to the alarming spread of resistance to almost all available antimalarial drugs, novel therapeutic strategies are urgently needed. As the intracellular human malaria parasite Plasmodium falciparum depends entirely on the host to meet its nutrient requirements and the majority of its transmembrane transporters are essential and lack human orthologs, these have often been suggested as potential targets of novel antimalarial drugs. However, membrane proteins are less amenable to proteomic tools compared to soluble parasite proteins, and have thus not been characterised as well. While it had been proposed that P. falciparum had a lower number of transporters (2.5% of its predicted proteome) in comparison to most reference genomes, manual curation of information from various sources led to the identification of 197 known and putative transporter genes, representing almost 4% of all parasite genes, a proportion that is comparable to well-studied metazoan species. This transporter list presented here was compiled by collating data from several databases along with extensive literature searches, and includes parasite-encoded membrane-resident/associated channels, carriers, and pumps that are located within the parasite or exported to the host cell. It provides updated information on the substrates, subcellular localisation, class, predicted essentiality, and the presence or absence of human orthologs of P. falciparum transporters to quickly identify essential proteins without human orthologs for further functional characterisation and potential exploitation as novel drug targets.
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Affiliation(s)
- Juliane Wunderlich
- Max Planck Institute for Infection Biology, Berlin, Germany
- European Molecular Biology Laboratory, Hamburg Unit, Hamburg, Germany
- Centre for Structural Systems Biology, Hamburg, Germany
- *Correspondence: Juliane Wunderlich,
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Abstract
Protozoan parasites continue to cause a significant health and economic burden worldwide. As infectious organisms, they pose unique and difficult challenges due to a level of conservation of critical eukaryotic cellular pathways with their hosts. Gene regulation has been pinpointed as an essential pathway with enough divergence to warrant investigation into therapeutically targeting. Examination of human parasites such as Plasmodium falciparum, Toxoplasma gondii, and kinetoplastids have revealed that epigenetic mechanisms play a key role in their gene regulation. The enzymes involved in adding and removing epigenetic posttranslational modifications (PTMs) have historically been the focus of study. However, the reader proteins that recognize and bind PTMs, initiating recruitment of chromatin-modifying and transcription complexes, are now being realized for their critical role in regulation and their potential as drug targets. In this review, we highlight the current knowledge on epigenetic reader proteins in model parasitic protozoa, focusing on the histone acyl- and methyl-reading domains. With this knowledge base, we compare differences between medically relevant parasites, discuss conceivable functions of these understudied proteins, indicate gaps in knowledge, and provide current progress in drug development.
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Affiliation(s)
- Krista Fleck
- Molecular, Cellular and Biomedical Sciences, University of New Hampshire, Durham, New Hampshire, United States of America
| | - Malorie Nitz
- Molecular, Cellular and Biomedical Sciences, University of New Hampshire, Durham, New Hampshire, United States of America
| | - Victoria Jeffers
- Molecular, Cellular and Biomedical Sciences, University of New Hampshire, Durham, New Hampshire, United States of America
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m6A RNA methylation facilitates pre-mRNA 3'-end formation and is essential for viability of Toxoplasma gondii. PLoS Pathog 2021; 17:e1009335. [PMID: 34324585 PMCID: PMC8354455 DOI: 10.1371/journal.ppat.1009335] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 08/10/2021] [Accepted: 07/16/2021] [Indexed: 12/19/2022] Open
Abstract
Toxoplasma gondii is an obligate intracellular parasite that can cause serious opportunistic disease in the immunocompromised or through congenital infection. To progress through its life cycle, Toxoplasma relies on multiple layers of gene regulation that includes an array of transcription and epigenetic factors. Over the last decade, the modification of mRNA has emerged as another important layer of gene regulation called epitranscriptomics. Here, we report that epitranscriptomics machinery exists in Toxoplasma, namely the methylation of adenosines (m6A) in mRNA transcripts. We identified novel components of the m6A methyltransferase complex and determined the distribution of m6A marks within the parasite transcriptome. m6A mapping revealed the modification to be preferentially located near the 3’-boundary of mRNAs. Knockdown of the m6A writer components METTL3 and WTAP resulted in diminished m6A marks and a complete arrest of parasite replication. Furthermore, we examined the two proteins in Toxoplasma that possess YTH domains, which bind m6A marks, and showed them to be integral members of the cleavage and polyadenylation machinery that catalyzes the 3’-end processing of pre-mRNAs. Loss of METTL3, WTAP, or YTH1 led to a defect in transcript 3’-end formation. Together, these findings establish that the m6A epitranscriptome is essential for parasite viability by contributing to the processing of mRNA 3’-ends. Toxoplasma gondii is a parasite of medical importance that causes disease upon immuno-suppression. Uncovering essential pathways that the parasite uses for its basic biological processes may reveal opportunities for new anti-parasitic drug therapies. Here, we describe the machinery that Toxoplasma uses to modify specific adenosine residues within its messenger RNAs (mRNA) by N6-adenosine methylation (m6A). We discovered that m6A mRNA methylation is prevalent in multiple stages of the parasite life cycle and is required for parasite replication. We also establish that m6A plays a major role in the proper maturation of mRNA. Two proteins that bind m6A modifications on mRNA associate with factors responsible for the cleavage and final processing steps of mRNA maturation. Since all of the machinery is conserved from plants to Toxoplasma and other related parasites, we propose that this system operates similarly in these organisms.
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