1
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Moescheid MF, Puckelwaldt O, Beutler M, Haeberlein S, Grevelding CG. Defining an optimal control for RNAi experiments with adult Schistosoma mansoni. Sci Rep 2023; 13:9766. [PMID: 37328492 PMCID: PMC10276032 DOI: 10.1038/s41598-023-36826-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Accepted: 06/10/2023] [Indexed: 06/18/2023] Open
Abstract
In parasites such as Schistosoma mansoni, gene knockdown by RNA interference (RNAi) has become an indispensable tool for functional gene characterization. To distinguish target-specific RNAi effects versus off-target effects, controls are essential. To date, however, there is still no general agreement about suitable RNAi controls, which limits the comparability between studies. To address this point, we investigated three selected dsRNAs for their suitability as RNAi controls in experiments with adult S. mansoni in vitro. Two dsRNAs were of bacterial origin, the neomycin resistance gene (neoR) and the ampicillin resistance gene (ampR). The third one, the green fluorescent protein gene (gfp), originated from jellyfish. Following dsRNA application, we analyzed physiological parameters like pairing stability, motility, and egg production as well as morphological integrity. Furthermore, using RT-qPCR we evaluated the potential of the used dsRNAs to influence transcript patterns of off-target genes, which had been predicted by si-Fi (siRNA-Finder). At the physiological and morphological levels, we observed no obvious changes in the dsRNA treatment groups compared to an untreated control. However, we detected remarkable differences at the transcript level of gene expression. Amongst the three tested candidates, we suggest dsRNA of the E. coli ampR gene as the most suitable RNAi control.
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Affiliation(s)
- Max F Moescheid
- Institute of Parasitology, Biomedical Research Center Seltersberg (BFS), Justus Liebig University Giessen, Giessen, Germany
| | - Oliver Puckelwaldt
- Institute of Parasitology, Biomedical Research Center Seltersberg (BFS), Justus Liebig University Giessen, Giessen, Germany
| | - Mandy Beutler
- Institute of Parasitology, Biomedical Research Center Seltersberg (BFS), Justus Liebig University Giessen, Giessen, Germany
| | - Simone Haeberlein
- Institute of Parasitology, Biomedical Research Center Seltersberg (BFS), Justus Liebig University Giessen, Giessen, Germany
| | - Christoph G Grevelding
- Institute of Parasitology, Biomedical Research Center Seltersberg (BFS), Justus Liebig University Giessen, Giessen, Germany.
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2
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Fairlamb AH, Wyllie S. The critical role of mode of action studies in kinetoplastid drug discovery. FRONTIERS IN DRUG DISCOVERY 2023; 3:fddsv.2023.1185679. [PMID: 37600222 PMCID: PMC7614965 DOI: 10.3389/fddsv.2023.1185679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/22/2023]
Abstract
Understanding the target and mode of action of compounds identified by phenotypic screening can greatly facilitate the process of drug discovery and development. Here, we outline the tools currently available for target identification against the neglected tropical diseases, human African trypanosomiasis, visceral leishmaniasis and Chagas' disease. We provide examples how these tools can be used to identify and triage undesirable mechanisms, to identify potential toxic liabilities in patients and to manage a balanced portfolio of target-based campaigns. We review the primary targets of drugs that are currently in clinical development that were initially identified via phenotypic screening, and whose modes of action affect protein turnover, RNA trans-splicing or signalling in these protozoan parasites.
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Affiliation(s)
- Alan H. Fairlamb
- Wellcome Centre for Anti-Infectives Research, Division of Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Susan Wyllie
- Wellcome Centre for Anti-Infectives Research, Division of Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, Dundee, United Kingdom
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3
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Horjales S, Li Calzi M, Francia ME, Cayota A, Garcia-Silva MR. piRNA pathway evolution beyond gonad context: Perspectives from apicomplexa and trypanosomatids. Front Genet 2023; 14:1129194. [PMID: 36816026 PMCID: PMC9935688 DOI: 10.3389/fgene.2023.1129194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Accepted: 01/23/2023] [Indexed: 02/05/2023] Open
Abstract
piRNAs function as genome defense mechanisms against transposable elements insertions within germ line cells. Recent studies have unraveled that piRNA pathways are not limited to germ cells as initially reckoned, but are instead also found in non-gonadal somatic contexts. Moreover, these pathways have also been reported in bacteria, mollusks and arthropods, associated with safeguard of genomes against transposable elements, regulation of gene expression and with direct consequences in axon regeneration and memory formation. In this Perspective we draw attention to early branching parasitic protozoa, whose genome preservation is an essential function as in late eukaryotes. However, little is known about the defense mechanisms of these genomes. We and others have described the presence of putative PIWI-related machinery members in protozoan parasites. We have described the presence of a PIWI-like protein in Trypanosoma cruzi, bound to small non-coding RNAs (sRNAs) as cargo of secreted extracellular vesicles relevant in intercellular communication and host infection. Herein, we put forward the presence of members related to Argonaute pathways in both Trypanosoma cruzi and Toxoplasma gondii. The presence of PIWI-like machinery in Trypansomatids and Apicomplexa, respectively, could be evidence of an ancestral piRNA machinery that evolved to become more sophisticated and complex in multicellular eukaryotes. We propose a model in which ancient PIWI proteins were expressed broadly and had functions independent of germline maintenance. A better understanding of current and ancestral PIWI/piRNAs will be relevant to better understand key mechanisms of genome integrity conservation during cell cycle progression and modulation of host defense mechanisms by protozoan parasites.
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Affiliation(s)
- S. Horjales
- Apicomplexa Biology Laboratory, Institute Pasteur Montevideo, Montevideo, Uruguay
| | - M Li Calzi
- Functional Genomics Laboratory, Institute Pasteur Montevideo, Montevideo, Uruguay
| | - M. E. Francia
- Apicomplexa Biology Laboratory, Institute Pasteur Montevideo, Montevideo, Uruguay,Departamento de Parasitología y Micología, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - A. Cayota
- Functional Genomics Laboratory, Institute Pasteur Montevideo, Montevideo, Uruguay,Departmento Basico de Medicina, Facultad de Medicina, Hospital de Clinicas, Universidad de la República, Montevideo, Uruguay
| | - M. R. Garcia-Silva
- Functional Genomics Laboratory, Institute Pasteur Montevideo, Montevideo, Uruguay,*Correspondence: M. R. Garcia-Silva,
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4
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López-Escobar L, Hänisch B, Halliday C, Ishii M, Akiyoshi B, Dean S, Sunter JD, Wheeler RJ, Gull K. Stage-specific transcription activator ESB1 regulates monoallelic antigen expression in Trypanosoma brucei. Nat Microbiol 2022; 7:1280-1290. [PMID: 35879525 PMCID: PMC9352583 DOI: 10.1038/s41564-022-01175-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Accepted: 06/14/2022] [Indexed: 11/09/2022]
Abstract
Variant surface glycoprotein (VSG) coats bloodstream form Trypanosoma brucei parasites, and monoallelic VSG expression underpins the antigenic variation necessary for pathogenicity. One of thousands of VSG genes is transcribed by RNA polymerase I in a singular nuclear structure called the expression site body (ESB), but how monoallelic VSG transcription is achieved remains unclear. Using a localization screen of 153 proteins we found one, ESB-specific protein 1 (ESB1), that localized only to the ESB and is expressed only in VSG-expressing life cycle stages. ESB1 associates with DNA near the active VSG promoter and is necessary for VSG expression, with overexpression activating inactive VSG promoters. Mechanistically, ESB1 is necessary for recruitment of a subset of ESB components, including RNA polymerase I, revealing that the ESB has separately assembled subdomains. Because many trypanosomatid parasites have divergent ESB1 orthologues yet do not undergo antigenic variation, ESB1 probably represents an important class of transcription regulators.
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Affiliation(s)
| | - Benjamin Hänisch
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - Clare Halliday
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - Midori Ishii
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Bungo Akiyoshi
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Samuel Dean
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK.,Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry, UK
| | - Jack Daniel Sunter
- Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, UK.
| | | | - Keith Gull
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
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5
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Zhang L, Chen L, Zhang H, Si H, Liu X, Suo X, Hu D. A comparative study of microRNAs in different stages of Eimeria tenella. Front Vet Sci 2022; 9:954725. [PMID: 35937295 PMCID: PMC9353057 DOI: 10.3389/fvets.2022.954725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Accepted: 06/30/2022] [Indexed: 11/17/2022] Open
Abstract
Apicomplexan parasites have divergent biogenesis machinery for small RNA generation. Analysis has shown that parasites in Plasmodium and Cryptosporidium as well as many species in Leishmania or Trypanosoma do not have a complete machinery in small RNA biogenesis. Recently, the miRNA-generating system of Toxoplasma has been identified as plant/fungal-like and its miRNAome has been elucidated. However, the microRNA (miRNA) expression profiles and their potential regulatory functions in different stages of Eimeria tenella remain largely unknown. In this study, we characterized the RNA silencing machinery of E. tenella and investigated the miRNA population distribution at different life stages by high-throughput sequencing. We characterized the expression of miRNAs in the unsporulated oocyst, sporulated oocyst and schizogony stages, obtaining a total of 392 miRNAs. We identified 58 differentially expressed miRNAs between USO (unsporulated oocysts) and SO (sporulated oocysts) that were significantly enriched for their potential target genes in the regulation of gene expression and chromatin binding, suggesting an epigenetic modulation of sporulating by these miRNAs. In comparing miRNA expression at endogenous and exogenous developmental stages, twenty-four miRNAs were identified differently expressed. Those were mainly associated with the regulation of genes with protein kinase activity, suggesting control of protein phosphorylation. This is the first study about the evolution of miRNA biogenesis system and miRNA control of gene expression in Eimeria species. Our data may lead to functional insights into of the regulation of gene expression during parasite life cycle in apicomplexan parasites.
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Affiliation(s)
- Lei Zhang
- College of Animal Science and Technology, Guangxi University, Nanning, China
| | - Linlin Chen
- Key Laboratory of Animal Epidemiology and Zoonosis of Ministry of Agriculture, National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Hongtao Zhang
- College of Animal Science and Technology, Guangxi University, Nanning, China
| | - Hongbin Si
- College of Animal Science and Technology, Guangxi University, Nanning, China
| | - Xianyong Liu
- Key Laboratory of Animal Epidemiology and Zoonosis of Ministry of Agriculture, National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Xun Suo
- Key Laboratory of Animal Epidemiology and Zoonosis of Ministry of Agriculture, National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Dandan Hu
- College of Animal Science and Technology, Guangxi University, Nanning, China
- *Correspondence: Dandan Hu
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6
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Abstract
In eukaryotic organisms, noncoding RNAs (ncRNAs) have been implicated as important regulators of multifaceted biological processes, including transcriptional, posttranscriptional, and epigenetic regulation of gene expression. In recent years, it is becoming clear that protozoan parasites encode diverse ncRNA transcripts; however, little is known about their cellular functions. Recent advances in high-throughput “omic” studies identified many novel long ncRNAs (lncRNAs) in apicomplexan parasites, some of which undergo splicing, polyadenylation, and encode small proteins. To date, only a few of them are characterized, leaving a big gap in our understanding regarding their origin, mode of action, and functions in parasite biology. In this review, we focus on lncRNAs of the human malaria parasite Plasmodium falciparum and highlight their cellular functions and possible mechanisms of action.
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Affiliation(s)
- Karina Simantov
- Department of Microbiology & Molecular Genetics, The Kuvin Center for the Study of Infectious and Tropical Diseases, IMRIC, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Manish Goyal
- Department of Microbiology & Molecular Genetics, The Kuvin Center for the Study of Infectious and Tropical Diseases, IMRIC, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Ron Dzikowski
- Department of Microbiology & Molecular Genetics, The Kuvin Center for the Study of Infectious and Tropical Diseases, IMRIC, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
- * E-mail:
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7
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Oldrieve GR, Malacart B, López-Vidal J, Matthews KR. The genomic basis of host and vector specificity in non-pathogenic trypanosomatids. Biol Open 2022; 11:bio059237. [PMID: 35373253 PMCID: PMC9099014 DOI: 10.1242/bio.059237] [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: 01/19/2022] [Accepted: 03/25/2022] [Indexed: 11/20/2022] Open
Abstract
Trypanosoma theileri, a non-pathogenic parasite of bovines, has a predicted surface protein architecture that likely aids survival in its mammalian host. Their surface proteins are encoded by genes which account for ∼10% of their genome. A non-pathogenic parasite of sheep, Trypanosoma melophagium, is transmitted by the sheep ked and is closely related to T. theileri. To explore host and vector specificity between these species, we sequenced the T. melophagium genome and transcriptome and an annotated draft genome was assembled. T. melophagium was compared to 43 kinetoplastid genomes, including T. theileri. T. melophagium and T. theileri have an AT biased genome, the greatest bias of publicly available trypanosomatids. This trend may result from selection acting to decrease the genomic nucleotide cost. The T. melophagium genome is 6.3Mb smaller than T. theileri and large families of proteins, characteristic of the predicted surface of T. theileri, were found to be absent or greatly reduced in T. melophagium. Instead, T. melophagium has modestly expanded protein families associated with the avoidance of complement-mediated lysis. We propose that the contrasting genomic features of these species is linked to their mode of transmission from their insect vector to their mammalian host. This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Guy R. Oldrieve
- Institute of Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, UK
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8
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Cohen A, Azas N. Challenges and Tools for In Vitro Leishmania Exploratory Screening in the Drug Development Process: An Updated Review. Pathogens 2021; 10:1608. [PMID: 34959563 PMCID: PMC8703296 DOI: 10.3390/pathogens10121608] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Revised: 12/03/2021] [Accepted: 12/07/2021] [Indexed: 12/13/2022] Open
Abstract
Leishmaniases are a group of vector-borne diseases caused by infection with the protozoan parasites Leishmania spp. Some of them, such as Mediterranean visceral leishmaniasis, are zoonotic diseases transmitted from vertebrate to vertebrate by a hematophagous insect, the sand fly. As there is an endemic in more than 90 countries worldwide, this complex and major health problem has different clinical forms depending on the parasite species involved, with the visceral form being the most worrying since it is fatal when left untreated. Nevertheless, currently available antileishmanial therapies are significantly limited (low efficacy, toxicity, adverse side effects, drug-resistance, length of treatment, and cost), so there is an urgent need to discover new compounds with antileishmanial activity, which are ideally inexpensive and orally administrable with few side effects and a novel mechanism of action. Therefore, various powerful approaches were recently applied in many interesting antileishmanial drug development programs. The objective of this review is to focus on the very first step in developing a potential drug and to identify the exploratory methods currently used to screen in vitro hit compounds and the challenges involved, particularly in terms of harmonizing the results of work carried out by different research teams. This review also aims to identify innovative screening tools and methods for more extensive use in the drug development process.
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Affiliation(s)
- Anita Cohen
- IHU Méditerranée Infection, Aix Marseille University, IRD (Institut de Recherche pour le Développement), AP-HM (Assistance Publique—Hôpitaux de Marseille), SSA (Service de Santé des Armées), VITROME (Vecteurs—Infections Tropicales et Méditerranéennes), 13005 Marseille, France;
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9
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Mehlhorn S, Hunnekuhl VS, Geibel S, Nauen R, Bucher G. Establishing RNAi for basic research and pest control and identification of the most efficient target genes for pest control: a brief guide. Front Zool 2021; 18:60. [PMID: 34863212 PMCID: PMC8643023 DOI: 10.1186/s12983-021-00444-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 11/04/2021] [Indexed: 11/14/2022] Open
Abstract
RNA interference (RNAi) has emerged as a powerful tool for knocking-down gene function in diverse taxa including arthropods for both basic biological research and application in pest control. The conservation of the RNAi mechanism in eukaryotes suggested that it should-in principle-be applicable to most arthropods. However, practical hurdles have been limiting the application in many taxa. For instance, species differ considerably with respect to efficiency of dsRNA uptake from the hemolymph or the gut. Here, we review some of the most frequently encountered technical obstacles when establishing RNAi and suggest a robust procedure for establishing this technique in insect species with special reference to pests. Finally, we present an approach to identify the most effective target genes for the potential control of agricultural and public health pests by RNAi.
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Affiliation(s)
- Sonja Mehlhorn
- Crop Science Division, Bayer AG, R&D, Pest Control, Alfred-Nobel-Straße 50, 40789, Monheim, Germany
- Department of Evolutionary Developmental Genetics, Johann-Friedrich-Blumenbach Institute, GZMB, University of Göttingen, Göttingen, Germany
| | - Vera S Hunnekuhl
- Department of Evolutionary Developmental Genetics, Johann-Friedrich-Blumenbach Institute, GZMB, University of Göttingen, Göttingen, Germany
| | - Sven Geibel
- Crop Science Division, Bayer AG, R&D, Pest Control, Alfred-Nobel-Straße 50, 40789, Monheim, Germany
| | - Ralf Nauen
- Crop Science Division, Bayer AG, R&D, Pest Control, Alfred-Nobel-Straße 50, 40789, Monheim, Germany
| | - Gregor Bucher
- Department of Evolutionary Developmental Genetics, Johann-Friedrich-Blumenbach Institute, GZMB, University of Göttingen, Göttingen, Germany.
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10
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RISC in Entamoeba histolytica: Identification of a Protein-Protein Interaction Network for the RNA Interference Pathway in a Deep-Branching Eukaryote. mBio 2021; 12:e0154021. [PMID: 34488447 PMCID: PMC8546589 DOI: 10.1128/mbio.01540-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Entamoeba histolytica is a protozoan parasite that causes amebiasis in humans and is a major health concern in developing countries. Our previous work revealed a functional RNA interference (RNAi) pathway in Entamoeba. Several unusual features encompass the RNAi pathway in the parasite, including small RNAs (sRNAs) with a 5'-polyphosphate structure (identified to date only in Entamoeba and nematodes) and the conspicuous absence of a canonical Dicer enzyme. Currently, little is known about the Entamoeba RNA-induced silencing complex (RISC), which is critical in understanding how RNAi is achieved in the parasite. In this study, we examined the RISC of EhAgo2-2, the most highly expressed Argonaute protein in Entamoeba. We identified 43 protein components of EhAgo2-2 RISC with a broad range of functional activities. Two proteins with nucleosome assembly protein (NAP) domains, not previously observed in other RNAi systems, were identified as novel core members of amebic RISC. We further demonstrated the interaction of these NAPs with Ago using an in vitro recombinant system. Finally, we characterized the interaction network of five RISC components identified in this study to further elucidate the interactions of these RNAi pathway proteins. Our data suggest the presence of closely interacting protein groups within RISC and allowed us to build a map of protein-protein interactions in relation to Ago. Our work is the first to elucidate RISC components in Entamoeba and expands the current knowledge of RISC to a deep-branching single-celled eukaryote. IMPORTANCE Entamoeba histolytica is a leading parasitic cause of death in developing countries, and our efforts are focused on defining the molecular basis of RNA interference (RNAi) gene regulation in this parasite. The Entamoeba RNAi pathway effectively silences a subset of endogenous genes and has also been harnessed as a gene silencing tool to study gene function in this organism. However, little is known about the components of the Entamoeba RNA-induced silencing complex (RISC), which is critical in understanding how gene silencing is achieved in the parasite. This study characterizes, for the first time, the RISC components in Entamoeba and provides new insights in understanding the molecular regulatory mechanisms of RNAi in this parasite, including the demonstration of novel Ago protein-interacting partners. From an evolutionary point of view, our findings expand the current knowledge of RISC to a deep-branching single-celled eukaryote.
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11
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Cao Y, Xu X, Jiang L. Integrative analysis of the RNA interference toolbox in two Salicaceae willow species, and their roles in stress response in poplar (Populus trichocarpa Torr. & Gray). Int J Biol Macromol 2020; 162:1127-1139. [DOI: 10.1016/j.ijbiomac.2020.06.235] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 05/31/2020] [Accepted: 06/24/2020] [Indexed: 10/24/2022]
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Beneke T, Gluenz E. Bar-seq strategies for the LeishGEdit toolbox. Mol Biochem Parasitol 2020; 239:111295. [PMID: 32659298 DOI: 10.1016/j.molbiopara.2020.111295] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Revised: 06/16/2020] [Accepted: 06/22/2020] [Indexed: 11/24/2022]
Abstract
The number of fully sequenced genomes increases steadily but the function of many genes remains unstudied. To accelerate dissection of gene function in Leishmania spp. and other kinetoplastids we previously developed a streamlined pipeline for CRISPR-Cas9 gene editing, which we termed LeishGEdit. To facilitate high-throughput mutant screens we have adapted this pipeline by barcoding mutants with unique 17-nucleotide barcodes, allowing loss-of-function screens in mixed populations. Here we present primer design and analysis tools that facilitate these bar-seq strategies. We have developed a standalone easy-to-use pipeline to design CRISPR primers suitable for the LeishGEdit toolbox for any given genome and have generated a list of 14,995 barcodes. Barcodes and oligo sequences are now accessible through our website www.leishgedit.net allowing researchers to pursue bar-seq experiments in all currently available TriTrypDB genomes (release 41). This will streamline CRISPR bar-seq assays in kinetoplastids, enabling pooled mutant screens across the community.
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Affiliation(s)
- Tom Beneke
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford, OX1 3RE, UK.
| | - Eva Gluenz
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford, OX1 3RE, UK; The Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity and Inflammation, University of Glasgow, 120 University Place, Glasgow G12 8TA, UK
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13
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Functional Characterization of Entamoeba histolytica Argonaute Proteins Reveals a Repetitive DR-Rich Motif Region That Controls Nuclear Localization. mSphere 2019; 4:4/5/e00580-19. [PMID: 31619501 PMCID: PMC6796981 DOI: 10.1128/msphere.00580-19] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
The RNA interference (RNAi) pathway regulates gene expression in many eukaryotic organisms. Argonaute (Ago) proteins, together with bound small RNAs (sRNAs), are key effectors that mediate gene silencing function. However, there is limited knowledge of Ago proteins and their functions in nonmodel systems. In the protozoan parasite Entamoeba histolytica, RNAi is a robust means for stable gene silencing mediated via large populations of antisense sRNAs. Here, we report functional characterization of three Ago proteins in E. histolytica (EhAgo2-1, EhAgo2-2, and EhAgo2-3). Our data show that each EhAgo protein has a distinct subcellular localization and binds 27-nucleotide (nt) sRNAs and that the localization of EhAgo proteins is altered in response to stress conditions. Via mutagenesis analyses, we demonstrated that the Ago PAZ (Piwi/Argonaute/Zwille) domain in all three EhAgos is essential for sRNA binding. With mutation of the PAZ domain in EhAgo2-2, there was no effect on the nuclear localization of the protein but a strong phenotype and a growth defect. We further show that EhAgo2-2 contains an unusual repetitive DR-rich (aspartic acid, arginine-rich) motif region which functions as a nuclear localization signal (NLS) and is both necessary and sufficient to mediate nuclear localization. Overall, our data delineate the localization and sRNA binding features of the three E. histolytica Ago proteins and demonstrate that the PAZ domain is necessary for sRNA binding. The repetitive DR-rich motif region in EhAgo2-2 has not previously been defined in other systems, which adds to the novel observations that can be made when studies of the RNAi pathway are extended to nonmodel systems.IMPORTANCE The protozoan parasite Entamoeba histolytica, which causes amebiasis and affects over 50 million people worldwide, contains an important RNAi pathway for gene silencing. Gene silencing via the RNAi pathway is mediated by the Argonaute (Ago) proteins. However, we lack knowledge on Ago function(s) in this nonmodel system. In this paper, we discovered that three E. histolytica Ago proteins (EhAgo2-1, EhAgo2-2, and EhAgo2-3) all bind 27-nt small RNAs and have distinct subcellular localizations, which change in response to stress conditions. The EhAgos bind small RNA populations via their PAZ domains. An unusual repetitive DR-rich motif region is identified in EhAgo2-2 that functions as a nuclear localization signal. Our results show for the first time an active nuclear transport process of the EhAgo2-2 RNA-induced silencing complex (RISC) in this parasite. These data add to the novel observations that can be made when studies of the RNAi pathway are extended to nonmodel systems.
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14
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Gupta AK, Tatineni S. RNA silencing suppression mechanisms of Triticum mosaic virus P1: dsRNA binding property and mapping functional motifs. Virus Res 2019; 269:197640. [DOI: 10.1016/j.virusres.2019.197640] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Revised: 06/08/2019] [Accepted: 06/14/2019] [Indexed: 11/24/2022]
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Abstract
Cosmid libraries can represent an entire genome in a library of circular DNA molecules, allowing for the faithful amplification, cloning and isolation of large genomic DNA fragments. Moreover, using the so-called shuttle cosmid vectors, genomic DNA may be propagated in bacteria and in eukaryotic cells, which is a prerequisite for classic functional cloning and for the newly described Cos-Seq strategies.
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Affiliation(s)
- Joachim Clos
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany.
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16
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A new level of complexity in parasite-host interaction: The role of extracellular vesicles. ADVANCES IN PARASITOLOGY 2019; 104:39-112. [PMID: 31030771 DOI: 10.1016/bs.apar.2019.02.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Humans and animals have co-existed with parasites in a battle of constant adaptation to one another. It is becoming increasingly clear that extracellular vesicles (EVs) play important roles in this co-existence and pathology. This chapter reviews the current research on EVs released by protozoa, nematodes, trematodes, and cestodes with a special focus on EVs in parasite life cycles. The environmental changes experienced by the parasite during its life cycle is associated with distinct changes in EV release and content. The function of these EV seems to have a significant influence on parasite pathology and survival in the host by concomitantly modulating host immune responses and triggering parasite differentiation. The role of EVs in communication between the parasites and the host adds a new level of complexity in our understanding of parasite biology, which may be a key to further understand the complexity behind host-parasite interactions and communication. This increased understanding can, in turn, open up new avenues for vaccine, diagnostic, and therapeutic development for a wide variety of diseases such as parasite infection, cancers, and immunological disorders.
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Chatelain E, Ioset JR. Phenotypic screening approaches for Chagas disease drug discovery. Expert Opin Drug Discov 2017; 13:141-153. [PMID: 29235363 DOI: 10.1080/17460441.2018.1417380] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
INTRODUCTION Chagas disease, caused by the parasite Trypanosoma cruzi, is a global public health issue. Current treatments targeting the parasite are limited to two old nitroheterocyclic drugs with serious side effects. The need for new and safer drugs has prompted numerous drug discovery efforts to identify compounds suitable for parasitological cure in the last decade. Areas covered: Target-based drug discovery has been limited by the small number of well-validated targets - the latest example being the failure of azoles, T. cruzi CYP51 inhibitors, in proof-of-concept clinical trials; instead phenotypic-based drug discovery has become the main pillar of Chagas R&D. Rather than focusing on the technical features of these screening assays, the authors describe the different assays developed and available in the field, and provide a critical view on their values and limitations in the screening cascade for Chagas drug development. Expert opinion: The application of technological advances to the field of Chagas disease has led to a variety of phenotypic assays that have not only changed the disease discovery landscape but have also helped us to gain a better understanding of parasite/host interactions. Recent examples of target resolution from phenotypic hits will uncover new opportunities for drug discovery for Chagas disease.
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Affiliation(s)
- Eric Chatelain
- a Drugs for Neglected Diseases initiative (DNDi), R&D Department , Geneva , Switzerland
| | - Jean-Robert Ioset
- a Drugs for Neglected Diseases initiative (DNDi), R&D Department , Geneva , Switzerland
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18
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Molecular mechanisms of Dicer: endonuclease and enzymatic activity. Biochem J 2017; 474:1603-1618. [PMID: 28473628 PMCID: PMC5415849 DOI: 10.1042/bcj20160759] [Citation(s) in RCA: 142] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Revised: 02/27/2017] [Accepted: 03/01/2017] [Indexed: 12/12/2022]
Abstract
The enzyme Dicer is best known for its role as a riboendonuclease in the small RNA pathway. In this canonical role, Dicer is a critical regulator of the biogenesis of microRNA and small interfering RNA, as well as a growing number of additional small RNAs derived from various sources. Emerging evidence demonstrates that Dicer's endonuclease role extends beyond the generation of small RNAs; it is also involved in processing additional endogenous and exogenous substrates, and is becoming increasingly implicated in regulating a variety of other cellular processes, outside of its endonuclease function. This review will describe the canonical and newly identified functions of Dicer.
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Liu XJ, Xie L, Liu N, Zhan S, Zhou XG, Wang Q. RNA interference unveils the importance of Pseudotrichonympha grassii cellobiohydrolase, a protozoan exoglucanase, in termite cellulose degradation. INSECT MOLECULAR BIOLOGY 2017; 26:233-242. [PMID: 27991709 DOI: 10.1111/imb.12287] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Based on prior work, a cellulase from glycosyl hydrolase family 7 (GHF7) was identified and found to be expressed at a high level in Coptotermes formosanus. To determine the function of GHF7 family members in vivo, we used RNA interference (RNAi) to functionally analyse the exoglucanase gene Pseudotrichonympha grassii cellobiohydrolase gene (PgCBH), which was highly expressed in Pseudotrichonympha grassii, a flagellate found in the hindgut of C. formosanus. In this study, the expression level of PgCBH was down-regulated by RNAi, causing the death of P. grassii, but no effect was observed for other flagellates found in C. formosanus. RNAi also resulted in significantly reduced exoglucanase activity, and no effect was observed for endoglucanase and β-glucosidase activities. This result demonstrated that the PgCBH gene plays a role in the protist lignocellulolytic process and is also important for host survival. PgCBH can be used as a target gene and has potential as a bioinsecticide for use against termites.
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Affiliation(s)
- X-J Liu
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Shanghai, China
| | - L Xie
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Shanghai, China
| | - N Liu
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Shanghai, China
| | - S Zhan
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - X-G Zhou
- Department of Entomology, University of Kentucky, KY, USA
| | - Q Wang
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
- Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, China
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20
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The Evolutionary Loss of RNAi Key Determinants in Kinetoplastids as a Multiple Sporadic Phenomenon. J Mol Evol 2017; 84:104-115. [PMID: 28210761 DOI: 10.1007/s00239-017-9780-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Accepted: 01/28/2017] [Indexed: 12/11/2022]
Abstract
We screened the genomes of a broad panel of kinetoplastid protists for genes encoding proteins associated with the RNA interference (RNAi) system using probes from the Argonaute (AGO1), Dicer1 (DCL1), and Dicer2 (DCL2) genes of Leishmania brasiliensis and Crithidia fasciculata. We identified homologs for all the three of these genes in the genomes of a subset of these organisms. However, several of these organisms lacked evidence for any of these genes, while others lacked only DCL2. The open reading frames encoding these putative proteins were structurally analyzed in silico. The alignments indicated that the genes are homologous with a high degree of confidence, and three-dimensional structural models strongly supported a functional relationship to previously characterized AGO1, DCL1, and DCL2 proteins. Phylogenetic analysis of these putative proteins showed that these genes, when present, evolved in parallel with other nuclear genes, arguing that the RNAi system genes share a common progenitor, likely across all Kinetoplastea. In addition, the genome segments bearing these genes are highly conserved and syntenic, even among those taxa in which they are absent. However, taxa in which these genes are apparently absent represent several widely divergent branches of kinetoplastids, arguing that these genes were independently lost at least six times in the evolutionary history of these organisms. The mechanisms responsible for the apparent coordinate loss of these RNAi system genes independently in several lineages of kinetoplastids, while being maintained in other related lineages, are currently unknown.
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Morgado P, Manna D, Singh U. Recent advances in Entamoeba biology: RNA interference, drug discovery, and gut microbiome. F1000Res 2016; 5:2578. [PMID: 27853522 PMCID: PMC5089142 DOI: 10.12688/f1000research.9241.1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 10/17/2016] [Indexed: 01/04/2023] Open
Abstract
In recent years, substantial progress has been made in understanding the molecular and cell biology of the human parasite
Entamoeba histolytica, an important pathogen with significant global impact. This review outlines some recent advances in the
Entamoeba field in the last five years, focusing on areas that have not recently been discussed in detail: (i) molecular mechanisms regulating parasite gene expression, (ii) new efforts at drug discovery using high-throughput drug screens, and (iii) the effect of gut microbiota on amoebiasis.
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Affiliation(s)
- Pedro Morgado
- Division of Infectious Diseases, Department of Internal Medicine, Stanford University School of Medicine, Stanford, California, USA
| | - Dipak Manna
- Division of Infectious Diseases, Department of Internal Medicine, Stanford University School of Medicine, Stanford, California, USA
| | - Upinder Singh
- Division of Infectious Diseases, Department of Internal Medicine, Stanford University School of Medicine, Stanford, California, USA.,Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California, USA
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22
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Inhibition of Plasmodium falciparum proliferation in vitro by double-stranded RNA nanoparticle against malaria topoisomerase II. Exp Parasitol 2016; 164:84-90. [DOI: 10.1016/j.exppara.2016.03.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2015] [Revised: 03/02/2016] [Accepted: 03/04/2016] [Indexed: 11/21/2022]
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Linhares-Lacerda L, Morrot A. Role of Small RNAs in Trypanosomatid Infections. Front Microbiol 2016; 7:367. [PMID: 27065454 PMCID: PMC4811879 DOI: 10.3389/fmicb.2016.00367] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Accepted: 03/07/2016] [Indexed: 12/28/2022] Open
Abstract
Trypanosomatid parasites survive and replicate in the host by using mechanisms that aim to establish a successful infection and ensure parasite survival. Evidence points to microRNAs as new players in the host-parasite interplay. MicroRNAs are small non-coding RNAs that control proteins levels via post-transcriptional gene down-regulation, either within the cells where they were produced or in other cells via intercellular transfer. These microRNAs can be modulated in host cells during infection and are among the growing group of small regulatory RNAs, for which many classes have been described, including the transfer RNA-derived small RNAs. Parasites can either manipulate microRNAs to evade host-driven damage and/or transfer small RNAs to host cells. In this mini-review, we present evidence for the involvement of small RNAs, such as microRNAs, in trypanosomatid infections which lack RNA interference. We highlight both microRNA profile alterations in host cells during those infections and the horizontal transfer of small RNAs and proteins from parasites to the host by membrane-derived extracellular vesicles in a cell communication mechanism.
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Affiliation(s)
- Leandra Linhares-Lacerda
- Oswaldo Cruz Foundation, Laboratory on Thymus Research, Institute Oswaldo Cruz Rio de Janeiro, Brazil
| | - Alexandre Morrot
- Department of Immunology, Microbiology Institute, Federal University of Rio de Janeiro Rio de Janeiro, Brazil
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Romaniuk MA, Cervini G, Cassola A. Regulation of RNA binding proteins in trypanosomatid protozoan parasites. World J Biol Chem 2016; 7:146-157. [PMID: 26981203 PMCID: PMC4768119 DOI: 10.4331/wjbc.v7.i1.146] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Revised: 08/04/2015] [Accepted: 01/29/2016] [Indexed: 02/05/2023] Open
Abstract
Posttranscriptional mechanisms have a critical role in the overall outcome of gene expression. These mechanisms are especially relevant in protozoa from the genus Trypanosoma, which is composed by death threatening parasites affecting people in Sub-saharan Africa or in the Americas. In these parasites the classic view of regulation of transcription initiation to modulate the products of a given gene cannot be applied. This is due to the presence of transcription start sites that give rise to long polycistronic units that need to be processed costranscriptionally by trans-splicing and polyadenylation to give mature monocistronic mRNAs. Posttranscriptional mechanisms such as mRNA degradation and translational repression are responsible for the final synthesis of the required protein products. In this context, RNA-binding proteins (RBPs) in trypanosomes have a relevant role as modulators of mRNA abundance and translational repression by associating to the 3’ untranslated regions in mRNA. Many different RBPs have been proposed to modulate cohorts of mRNAs in trypanosomes. However, the current understanding of their functions lacks a dynamic view on the different steps at which these RBPs are regulated. Here, we discuss different evidences to propose regulatory events for different RBPs in these parasites. These events vary from regulated developmental expression, to biogenesis of cytoplasmic ribonucleoprotein complexes in the nucleus, and condensation of RBPs and mRNA into large cytoplasmic granules. Finally, we discuss how newly identified posttranslational modifications of RBPs and mRNA metabolism-related proteins could have an enormous impact on the modulation of mRNA abundance. To understand these modifications is especially relevant in these parasites due to the fact that the enzymes involved could be interesting targets for drug therapy.
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25
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A tRNA methyltransferase paralog is important for ribosome stability and cell division in Trypanosoma brucei. Sci Rep 2016; 6:21438. [PMID: 26888608 PMCID: PMC4757839 DOI: 10.1038/srep21438] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Accepted: 01/18/2016] [Indexed: 02/06/2023] Open
Abstract
Most eukaryotic ribosomes contain 26/28S, 5S, and 5.8S large subunit ribosomal RNAs (LSU rRNAs) in addition to the 18S rRNA of the small subunit (SSU rRNA). However, in kinetoplastids, a group of organisms that include medically important members of the genus Trypanosoma and Leishmania, the 26/28S large subunit ribosomal RNA is uniquely composed of 6 rRNA fragments. In addition, recent studies have shown the presence of expansion segments in the large ribosomal subunit (60S) of Trypanosoma brucei. Given these differences in structure, processing and assembly, T. brucei ribosomes may require biogenesis factors not found in other organisms. Here, we show that one of two putative 3-methylcytidine methyltransferases, TbMTase37 (a homolog of human methyltransferase-like 6, METTL6), is important for ribosome stability in T. brucei. TbMTase37 localizes to the nucleolus and depletion of the protein results in accumulation of ribosomal particles lacking srRNA 4 and reduced levels of polysome associated ribosomes. We also find that TbMTase37 plays a role in cytokinesis, as loss of the protein leads to multi-flagellated and multi-nucleated cells.
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26
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Cao JY, Xu YP, Li W, Li SS, Rahman H, Cai XZ. Genome-Wide Identification of Dicer-Like, Argonaute, and RNA-Dependent RNA Polymerase Gene Families in Brassica Species and Functional Analyses of Their Arabidopsis Homologs in Resistance to Sclerotinia sclerotiorum. FRONTIERS IN PLANT SCIENCE 2016; 7:1614. [PMID: 27833632 PMCID: PMC5081487 DOI: 10.3389/fpls.2016.01614] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Accepted: 10/12/2016] [Indexed: 05/20/2023]
Abstract
RNA silencing is an important mechanism to regulate gene expression and antiviral defense in plants. Nevertheless, RNA silencing machinery in the important oil crop Brassica napus and function in resistance to the devastating fungal pathogen Sclerotinia sclerotiorum are not well-understood. In this study, gene families of RNA silencing machinery in B. napus were identified and their role in resistance to S. sclerotiorum was revealed. Genome of the allopolyploid species B. napus possessed 8 Dicer-like (DCL), 27 Argonaute (AGO), and 16 RNA-dependent RNA polymerase (RDR) genes, which included almost all copies from its progenitor species B. rapa and B. oleracea and three extra copies of RDR5 genes, indicating that the RDR5 group in B. napus appears to have undergone further expansion through duplication during evolution. Moreover, compared with Arabidopsis, some AGO and RDR genes such as AGO1, AGO4, AGO9, and RDR5 had significantly expanded in these Brassica species. Twenty-one out of 51 DCL, AGO, and RDR genes were predicted to contain calmodulin-binding transcription activators (CAMTA)-binding site (CGCG box). S. sclerotiorum inoculation strongly induced the expression of BnCAMTA3 genes while significantly suppressed that of some CGCG-containing RNA silencing component genes, suggesting that RNA silencing machinery might be targeted by CAMTA3. Furthermore, Arabidopsis mutant analyses demonstrated that dcl4-2, ago9-1, rdr1-1, rdr6-11, and rdr6-15 mutants were more susceptible to S. sclerotiorum, while dcl1-9 was more resistant. Our results reveal the importance of RNA silencing in plant resistance to S. sclerotiorum and imply a new mechanism of CAMTA function as well as RNA silencing regulation.
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Affiliation(s)
- Jia-Yi Cao
- Institute of Biotechnology, College of Agriculture and Biotechnology, Zhejiang UniversityHangzhou, China
| | - You-Ping Xu
- Center of Analysis and Measurement, Zhejiang UniversityHangzhou, China
| | - Wen Li
- Institute of Biotechnology, College of Agriculture and Biotechnology, Zhejiang UniversityHangzhou, China
| | - Shuang-Sheng Li
- Institute of Biotechnology, College of Agriculture and Biotechnology, Zhejiang UniversityHangzhou, China
| | - Hafizur Rahman
- Institute of Biotechnology, College of Agriculture and Biotechnology, Zhejiang UniversityHangzhou, China
| | - Xin-Zhong Cai
- Institute of Biotechnology, College of Agriculture and Biotechnology, Zhejiang UniversityHangzhou, China
- *Correspondence: Xin-Zhong Cai
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Padmashree D, Swamy NR. Computational identification of putative miRNAs and their target genes in pathogenic amoeba Naegleria fowleri. Bioinformation 2015; 11:550-7. [PMID: 26770029 PMCID: PMC4702033 DOI: 10.6026/97320630011550] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2015] [Accepted: 12/12/2015] [Indexed: 02/08/2023] Open
Abstract
Naegleria fowleri is a parasitic unicellular free living eukaryotic amoeba. The parasite spreads through contaminated water and causes primary amoebic meningoencephalitis (PAM). Therefore, it is of interest to understand its molecular pathogenesis. Hence, we analyzed the parasite genome for miRNAs (microRNAs) that are non-coding, single stranded RNA molecules. We identified 245 miRNAs using computational methods in N. fowleri, of which five miRNAs are conserved. The predicted miRNA targets were analyzed by using miRanda (software) and further studied the functions by subsequently annotating using AmiGo (a gene ontology web tool).
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Affiliation(s)
- Dyavegowda Padmashree
- Department of Biochemistry, Central College Campus, Bangalore University, Bangalore, Karnataka, India
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28
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Huang Q, Chen Y, Wang RW, Schwarz RS, Evans JD. Honey bee microRNAs respond to infection by the microsporidian parasite Nosema ceranae. Sci Rep 2015; 5:17494. [PMID: 26620304 PMCID: PMC4664923 DOI: 10.1038/srep17494] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Accepted: 10/30/2015] [Indexed: 01/17/2023] Open
Abstract
In order to study the effects of Nosema ceranae infection on honey bee microRNA (miRNA) expression, we deep-sequenced honey bee miRNAs daily across a full 6-day parasite reproduction cycle. Seventeen miRNAs were differentially expressed in honey bees infected by N. ceranae that potentially target over 400 genes predicted to primarily involve ion binding, signaling, the nucleus, transmembrane transport, and DNA binding. Based on Enzyme Code analysis, nine biological pathways were identified by screening target genes against the Kyoto Encyclopedia of Genes and Genomes (KEGG) database, seven of which involved metabolism. Our results suggest that differentially expressed miRNAs regulate metabolism related genes of host honey bees in response to N. ceranae infection.
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Affiliation(s)
- Qiang Huang
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Science, Kunming, 650223, China.,USDA-ARS Bee Research Laboratory, BARC-East Building 306, Beltsville, Maryland, 20705, USA
| | - Yanping Chen
- USDA-ARS Bee Research Laboratory, BARC-East Building 306, Beltsville, Maryland, 20705, USA
| | - Rui Wu Wang
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Science, Kunming, 650223, China
| | - Ryan S Schwarz
- USDA-ARS Bee Research Laboratory, BARC-East Building 306, Beltsville, Maryland, 20705, USA
| | - Jay D Evans
- USDA-ARS Bee Research Laboratory, BARC-East Building 306, Beltsville, Maryland, 20705, USA
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Teixeira AAR, de Vasconcelos VDCS, Colli W, Alves MJM, Giordano RJ. Trypanosoma cruzi Binds to Cytokeratin through Conserved Peptide Motifs Found in the Laminin-G-Like Domain of the gp85/Trans-sialidase Proteins. PLoS Negl Trop Dis 2015; 9:e0004099. [PMID: 26398185 PMCID: PMC4580646 DOI: 10.1371/journal.pntd.0004099] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Accepted: 08/31/2015] [Indexed: 11/19/2022] Open
Abstract
Background Chagas' disease, caused by the protozoan parasite Trypanosoma cruzi, is a disease that affects millions of people most of them living in South and Central Americas. There are few treatment options for individuals with Chagas' disease making it important to understand the molecular details of parasite infection, so novel therapeutic alternatives may be developed for these patients. Here, we investigate the interaction between host cell intermediate filament proteins and the T. cruzi gp85 glycoprotein superfamily with hundreds of members that have long been implicated in parasite cell invasion. Methodology/Principal Findings An in silico analysis was utilized to identify peptide motifs shared by the gp85 T. cruzi proteins and, using phage display, these selected peptide motifs were screened for their ability to bind to cells. One peptide, named TS9, showed significant cell binding capacity and was selected for further studies. Affinity chromatography, phage display and invasion assays revealed that peptide TS9 binds to cytokeratins and vimentin, and prevents T. cruzi cell infection. Interestingly, peptide TS9 and a previously identified binding site for intermediate filament proteins are disposed in an antiparallel β-sheet fold, present in a conserved laminin-G-like domain shared by all members of the family. Moreover, peptide TS9 overlaps with an immunodominant T cell epitope. Conclusions/Significance Taken together, the present study reinforces previous results from our group implicating the gp85 superfamily of glycoproteins and the intermediate filament proteins cytokeratin and vimentin in the parasite infection process. It also suggests an important role in parasite biology for the conserved laminin-G-like domain, present in all members of this large family of cell surface proteins. Chagas' disease affects millions of people worldwide and is caused by a microorganism called Trypanosoma cruzi. Treatment options for patients with Chagas' disease is still limited to a small number of drugs, all of them very toxic with important side effects that can be debilitating for the health of patients. Understanding the molecular details of how T. cruzi infects humans is an important step toward the development of new drugs for this disease. As part of its life cycle, T. cruzi has to invade cells in order to replicate and produce new parasites. This is a complex event, which involves different proteins produced by both the parasite and the human host cells. Among them, there is a large family of highly polymorphic T. cruzi proteins important to guide the parasite to the target cells. Here we show that notwithstanding their differences, all members of this family share a small region comprised of nine amino acids that is important for cell recognition and infection by the parasite. Exploring these findings may provide researchers with new insights on how to prevent T. cruzi cell invasion and lead to novel therapeutic alternative for this debilitating disease.
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Affiliation(s)
| | | | - Walter Colli
- Department of Biochemistry, Chemistry Institute, Universidade de São Paulo, São Paulo, Brazil
| | - Maria Júlia Manso Alves
- Department of Biochemistry, Chemistry Institute, Universidade de São Paulo, São Paulo, Brazil
| | - Ricardo José Giordano
- Department of Biochemistry, Chemistry Institute, Universidade de São Paulo, São Paulo, Brazil
- * E-mail:
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Zhang H, Ehrenkaufer GM, Manna D, Hall N, Singh U. High Throughput Sequencing of Entamoeba 27nt Small RNA Population Reveals Role in Permanent Gene Silencing But No Effect on Regulating Gene Expression Changes during Stage Conversion, Oxidative, or Heat Shock Stress. PLoS One 2015; 10:e0134481. [PMID: 26248204 PMCID: PMC4527709 DOI: 10.1371/journal.pone.0134481] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Accepted: 07/10/2015] [Indexed: 01/09/2023] Open
Abstract
The human parasite Entamoeba histolytica has an active RNA interference (RNAi) pathway with an extensive repertoire of 27nt small RNAs that silence genes. However the role of this pathway in regulating amebic biology remains unknown. In this study, we address whether silencing via 27nt small RNAs may be a mechanism for controlling gene expression changes during conversion between the trophozoite and cyst stages of the parasite. We sequenced small RNA libraries generated from trophozoites, early cysts, mature cysts, and excysting cells and mapped them to the E. invadens genome. Our results show that, as in E. histolytica, small RNAs in E. invadens are largely ~27nt in length, have an unusual 5'-polyphosphate structure and mediate gene silencing. However, when comparing the libraries from each developmental time-point we found few changes in the composition of the small RNA populations. Furthermore, genes targeted by small RNAs were permanently silenced with no changes in transcript abundance during development. Thus, the E. invadens 27nt small RNA population does not mediate gene expression changes during development. In order to assess the generalizability of our observations, we examined whether small RNAs may be regulating gene expression changes during stress response in E. histolytica. Comparison of the 27nt small RNA populations from E. histolytica trophozoites from basal conditions, or after heat shock or exposure to oxidative stress showed few differences. Similar to data in E. invadens development, genes targeted by small RNAs were consistently silenced and did not change expression under tested stress conditions. Thus, the biological roles of the 27nt small RNA population in Entamoeba remain elusive. However, as the first characterization of the RNAi pathway in E. invadens these data serve as a useful resource for the study of Entamoeba development and open the door to the development of RNAi-based gene silencing tools in E. invadens.
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Affiliation(s)
- Hanbang Zhang
- Division of Infectious Diseases, Department of Internal Medicine, Stanford University School of Medicine, Stanford, California, United States of America
| | - Gretchen M. Ehrenkaufer
- Division of Infectious Diseases, Department of Internal Medicine, Stanford University School of Medicine, Stanford, California, United States of America
| | - Dipak Manna
- Division of Infectious Diseases, Department of Internal Medicine, Stanford University School of Medicine, Stanford, California, United States of America
| | - Neil Hall
- Center for Genomic Research, Institute of Integrative Biology, Biosciences Building, University of Liverpool, Liverpool, United Kingdom
| | - Upinder Singh
- Division of Infectious Diseases, Department of Internal Medicine, Stanford University School of Medicine, Stanford, California, United States of America
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California, United States of America
- * E-mail:
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31
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Lambertz U, Oviedo Ovando ME, Vasconcelos EJR, Unrau PJ, Myler PJ, Reiner NE. Small RNAs derived from tRNAs and rRNAs are highly enriched in exosomes from both old and new world Leishmania providing evidence for conserved exosomal RNA Packaging. BMC Genomics 2015; 16:151. [PMID: 25764986 PMCID: PMC4352550 DOI: 10.1186/s12864-015-1260-7] [Citation(s) in RCA: 105] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Accepted: 01/21/2015] [Indexed: 01/09/2023] Open
Abstract
Background Leishmania use exosomes to communicate with their mammalian hosts and these secreted vesicles appear to contribute to pathogenesis by delivering protein virulence factors to macrophages. In other eukaryotes, exosomes were found to carry RNA cargo, such as mRNAs and small non-coding RNAs, capable of altering recipient cell phenotype. Whether leishmania exosomes also contain RNAs which they are able to deliver to bystander cells is not known. Here, we show that leishmania exosomes indeed contain RNAs and compare and contrast the RNA content of exosomes released by Leishmania donovani and Leishmania braziliensis. Results We purified RNA from exosomes collected from axenic amastigote culture supernatant and found that when compared with total leishmania RNA, exosomes mainly contained short RNA sequences. Exosomes with intact membranes were capable of protecting their RNA cargo from degradation by RNase. Moreover, exosome RNA cargo was delivered to host cell cytoplasm in vitro. Sequencing of exosomal RNA indicated that the majority of cargo sequences were derived from non-coding RNA species such as rRNA and tRNA. In depth analysis revealed the presence of tRNA-derived small RNAs, a novel RNA type with suspected regulatory functions. Northern blotting confirmed the specific and selective enrichment of tRNA-derived small RNAs in exosomes. We also identified a number of novel transcripts, which appeared to be specifically enriched in exosomes compared to total cell RNA. In addition, we observed the presence of sequences mapping to siRNA-coding regions in L. braziliensis , but not in L. donovani exosomes. Conclusions These results show that leishmania exosomes are selectively and specifically enriched in small RNAs derived almost exclusively from non-coding RNAs. These exosomes are competent to deliver their cargo of novel, potential small regulatory RNAs to macrophages where they may influence parasite-host cell interactions. The remarkably high degree of congruence in exosomal RNA content between L. donovani and L. braziliensis, argues for the presence of a conserved mechanism for exosomal RNA packaging in leishmania. These findings open up a new avenue of research on non-canonical, small RNA pathways in this trypanosomatid, which may elucidate pathogenesis and identify novel therapeutic approaches. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-1260-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Ulrike Lambertz
- Departments of Medicine, Microbiology and Immunology, University of British Columbia, Vancouver, BC, Canada.
| | - Mariana E Oviedo Ovando
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada.
| | | | - Peter J Unrau
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada.
| | - Peter J Myler
- Seattle Biomedical Research Institute, Seattle, WA, USA. .,Departments of Global Health and Biomedical Informatics & Medical Education, University of Washington, Washington, WA, USA.
| | - Neil E Reiner
- Departments of Medicine, Microbiology and Immunology, University of British Columbia, Vancouver, BC, Canada.
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Crater AK, Manni E, Ananvoranich S. Utilization of inherent miRNAs in functional analyses of Toxoplasma gondii genes. J Microbiol Methods 2015; 108:92-102. [DOI: 10.1016/j.mimet.2014.11.014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Revised: 11/26/2014] [Accepted: 11/26/2014] [Indexed: 10/24/2022]
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Fernandez-Calero T, Garcia-Silva R, Pena A, Robello C, Persson H, Rovira C, Naya H, Cayota A. Profiling of small RNA cargo of extracellular vesicles shed by Trypanosoma cruzi reveals a specific extracellular signature. Mol Biochem Parasitol 2015; 199:19-28. [DOI: 10.1016/j.molbiopara.2015.03.003] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Revised: 03/03/2015] [Accepted: 03/09/2015] [Indexed: 12/31/2022]
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Merritt C, Silva L, Tanner AL, Stuart K, Pollastri MP. Kinases as druggable targets in trypanosomatid protozoan parasites. Chem Rev 2014; 114:11280-304. [PMID: 26443079 PMCID: PMC4254031 DOI: 10.1021/cr500197d] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Indexed: 12/21/2022]
Affiliation(s)
- Christopher Merritt
- Seattle
Biomedical Research Institute, 307 Westlake Avenue North, Suite 500, Seattle, Washington 98109-5219, United States
| | - Lisseth
E. Silva
- Department
of Chemistry & Chemical Biology, Northeastern
University, 417 Egan
Research Center, 360 Huntington Avenue, Boston, Massachusetts 02115, United States
| | - Angela L. Tanner
- Department
of Chemistry & Chemical Biology, Northeastern
University, 417 Egan
Research Center, 360 Huntington Avenue, Boston, Massachusetts 02115, United States
| | - Kenneth Stuart
- Seattle
Biomedical Research Institute, 307 Westlake Avenue North, Suite 500, Seattle, Washington 98109-5219, United States
| | - Michael P. Pollastri
- Department
of Chemistry & Chemical Biology, Northeastern
University, 417 Egan
Research Center, 360 Huntington Avenue, Boston, Massachusetts 02115, United States
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Sinha S, Medhi B, Sehgal R. Challenges of drug-resistant malaria. ACTA ACUST UNITED AC 2014; 21:61. [PMID: 25402734 PMCID: PMC4234044 DOI: 10.1051/parasite/2014059] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2014] [Accepted: 10/23/2014] [Indexed: 01/09/2023]
Abstract
Over the past six decades, the drug resistance of Plasmodium falciparum has become an issue of utmost concern. Despite the remarkable progress that has been made in recent years in reducing the mortality rate to about 30% with the scaling-up of vector control, introduction of artemisinin-based combination therapies and other malaria control strategies, the confirmation of artemisinin resistance on the Cambodia–Thailand border threatened all the previous success. This review addresses the global scenario of antimalarial resistance and factors associated with it, with the main emphasis on futuristic approaches like nanotechnology and stem cell therapy that may impede resistant malaria, along with novel medications which are preparing to enter the global antimalarial market. These novel studies are likely to escalate over the coming years and will hopefully help to reduce the burden of malaria.
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Affiliation(s)
- Shweta Sinha
- Department of Medical Parasitology, Postgraduate Institute of Medical Education and Research, Chandigarh 160012, India
| | - Bikash Medhi
- Department of Pharmacology, Postgraduate Institute of Medical Education and Research, Chandigarh 160012, India
| | - Rakesh Sehgal
- Department of Medical Parasitology, Postgraduate Institute of Medical Education and Research, Chandigarh 160012, India
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Deep profiling of the novel intermediate-size noncoding RNAs in intraerythrocytic Plasmodium falciparum. PLoS One 2014; 9:e92946. [PMID: 24713982 PMCID: PMC3979661 DOI: 10.1371/journal.pone.0092946] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Accepted: 02/27/2014] [Indexed: 11/23/2022] Open
Abstract
Intermediate-size noncoding RNAs (is-ncRNAs) have been shown to play important regulatory roles in the development of several eukaryotic organisms. However, they have not been thoroughly explored in Plasmodium falciparum, which is the most virulent malaria parasite infecting human being. By using Illumina/Solexa paired-end sequencing of an is-ncRNA-specific library, we performed a systematic identification of novel is-ncRNAs in intraerythrocytic P. falciparum, strain 3D7. A total of 1,198 novel is-ncRNA candidates, including antisense, intergenic, and intronic is-ncRNAs, were identified. Bioinformatics analyses showed that the intergenic is-ncRNAs were the least conserved among different Plasmodium species, and antisense is-ncRNAs were more conserved than their sense counterparts. Twenty-two novel snoRNAs were identified, and eight potential novel classes of P. falciparum is-ncRNAs were revealed by clustering analysis. The expression of randomly selected novel is-ncRNAs was confirmed by RT-PCR and northern blotting assays. An obvious different expressional profile of the novel is-ncRNA between the early and late intraerythrocytic developmental stages of the parasite was observed. The expression levels of the antisense RNAs correlated with those of their cis-encoded sense RNA counterparts, suggesting that these is-ncRNAs are involved in the regulation of gene expression of the parasite. In conclusion, we accomplished a deep profiling analysis of novel is-ncRNAs in P. falciparum, analysed the conservation and structural features of these novel is-ncRNAs, and revealed their differential expression patterns during the development of the parasite. These findings provide important information for further functional characterisation of novel is-ncRNAs during the development of P. falciparum.
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Nühs A, Schäfer C, Zander D, Trübe L, Tejera Nevado P, Schmidt S, Arevalo J, Adaui V, Maes L, Dujardin JC, Clos J. A novel marker, ARM58, confers antimony resistance to Leishmania spp. Int J Parasitol Drugs Drug Resist 2014; 4:37-47. [PMID: 24596667 PMCID: PMC3940081 DOI: 10.1016/j.ijpddr.2013.11.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2013] [Revised: 11/22/2013] [Accepted: 11/25/2013] [Indexed: 12/22/2022]
Abstract
Protozoa of the Leishmania genus cause a variety of disease forms that rank at the top of the list of neglected tropical diseases. Anti-leishmanial drugs based on pentavalent antimony have been the mainstay of therapy for over 60 years and resistance against them is increasingly encountered in the field. The biochemical basis for this is poorly understood and likely diverse. No stringent correlation between genetic markers and antimony resistance has so far been shown, prompting us to use a functional cloning approach to identify markers of resistance. Using gene libraries derived from drug-resistant and drug-sensitive Leishmania braziliensis clinical isolates in a functional cloning strategy, we repeatedly selected one gene locus located on chromosome 20 whose amplification confers increased antimony (III) resistance in vitro to an otherwise sensitive L. braziliensis clone. The gene responsible for the effect encodes a previously hypothetical protein that we dubbed LbrARM58. It comprises four repeats of a domain of unknown function, DUF1935, one of them harbouring a potential trans-membrane domain. The gene is so far unique to the Leishmania genus, while a structurally related gene without antimony resistance functionality is also found in Trypanosoma spp. Overexpression of LbrARM58 also confers antimony resistance to promastigotes and intracellular amastigotes of the related species Leishmania infantum, indicating a conserved function in Old World and New World Leishmania species. Our results also show that in spite of their RNAi system, L. braziliensis promastigotes can serve as acceptor cells for episomally propagated cosmid libraries, at least for the initial stages of functional cloning efforts.
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Affiliation(s)
- Andrea Nühs
- Bernhard Nocht Institute for Tropical Medicine, D20359 Hamburg, Germany
| | - Carola Schäfer
- Bernhard Nocht Institute for Tropical Medicine, D20359 Hamburg, Germany
| | - Dorothea Zander
- Bernhard Nocht Institute for Tropical Medicine, D20359 Hamburg, Germany
| | - Leona Trübe
- Bernhard Nocht Institute for Tropical Medicine, D20359 Hamburg, Germany
| | | | - Sonja Schmidt
- Bernhard Nocht Institute for Tropical Medicine, D20359 Hamburg, Germany
| | - Jorge Arevalo
- Instituto de Medicina Tropical Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Vanessa Adaui
- Instituto de Medicina Tropical Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Louis Maes
- Department of Biomedical Sciences, Faculty of Pharmaceutical, Biomedical and Veterinary Sciences, University of Antwerp, Antwerp, Belgium
| | - Jean-Claude Dujardin
- Instituut voor Tropische Geneeskunde, Antwerp, Belgium
- Department of Biomedical Sciences, Faculty of Pharmaceutical, Biomedical and Veterinary Sciences, University of Antwerp, Antwerp, Belgium
| | - Joachim Clos
- Bernhard Nocht Institute for Tropical Medicine, D20359 Hamburg, Germany
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Yang M, Xiang Q, Zhang X, Li X, Sylla S, Ding Z. RNA interference targeting nucleocapsid protein inhibits porcine reproductive and respiratory syndrome virus replication in Marc-145 cells. J Microbiol 2014; 52:333-9. [PMID: 24682995 PMCID: PMC7090845 DOI: 10.1007/s12275-014-3419-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2013] [Revised: 01/28/2014] [Accepted: 03/12/2014] [Indexed: 01/16/2023]
Abstract
Porcine reproductive and respiratory syndrome (PRRS) is an important disease, which leads to severe economic losses in swine-producing areas of the world. However, current antiviral strategies cannot provide highly effective protection. In this study, three theoretically effective interference target sites (71–91, 144–164, 218–238) targeting the nucleocapsid (N) gene of PRRSV were designed and selected, and then three siRNA-expressing plasmids were constructed, respectively named p2.1-N71, p2.1-N144, and p2.1-N218. The recombinant siRNA-expressing plasmids were transfected into Marc-145 cells; then the cells were infected with PRRSV (JL07SW strain); finally, after incubation for 48 h, the antiviral activity of those siRNA-expressing plasmids in Marc-145 cells was assessed by cytopathic effects, virus titers, indirect immunofluorescence, and quantitative real-time PCR. Experimental results demonstrated that these three siRNA-expressing plasmids could effectively and significantly inhibit the replication of PRRSV by 93.2%, 83.6%, and 89.2% in Marc-145 cells, respectively. Among these three siRNA-expressing plasmids, p2.1-N71 was found to be most effective, while p2.1-N144 and p2.1-N218 displayed relatively weak inhibition of virus replication. The results indicated that siRNA-expressing plasmids targeting the N gene of PRRSV could significantly inhibit PRRSV replication in Marc-145 cells. Based on our experimental results and previous reports, the 71–91, 179–197, and 234–252 sites of the N gene are good choices to effectively inhibit the replication of PRRSV, and this RNA interference technique can be a potential anti-PRRSV strategy.
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Affiliation(s)
- Minnan Yang
- College of Veterinary Medicine, and Key Laboratory of Zoonosis Research, Ministry of Education, Institute of Zoonosis, Jilin University, Changchun, 130062, P. R. China
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Hashimoto M, Nara T, Hirawake H, Morales J, Enomoto M, Mikoshiba K. Antisense oligonucleotides targeting parasite inositol 1,4,5-trisphosphate receptor inhibits mammalian host cell invasion by Trypanosoma cruzi. Sci Rep 2014; 4:4231. [PMID: 24577136 PMCID: PMC3937783 DOI: 10.1038/srep04231] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2013] [Accepted: 02/06/2014] [Indexed: 11/17/2022] Open
Abstract
Chagas disease is caused by an intracellular parasitic protist, Trypanosoma cruzi. As there are no highly effective drugs against this agent that also demonstrate low toxicity, there is an urgent need for development of new drugs to treat Chagas disease. We have previously demonstrated that the parasite inositol 1,4,5-trisphosphate receptor (TcIP3R) is crucial for invasion of the mammalian host cell by T. cruzi. Here, we report that TcIP3R is a short-lived protein and that its expression is significantly suppressed in trypomastigotes. Treatment of trypomastigotes, an infective stage of T. cruzi, with antisense oligonucleotides specific to TcIP3R deceased TcIP3R protein levels and impaired trypomastigote invasion of host cells. Due to the resulting instability and very low expression level of TcIP3R in trypomastigotes indicates that TcIP3R is a promising target for antisense therapy in Chagas disease.
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Affiliation(s)
- Muneaki Hashimoto
- Department of Molecular and Cellular Parasitology, Juntendo University School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan
| | - Takeshi Nara
- Department of Molecular and Cellular Parasitology, Juntendo University School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan
| | - Hiroko Hirawake
- Department of Molecular and Cellular Parasitology, Juntendo University School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan
| | - Jorge Morales
- Department of Molecular and Cellular Parasitology, Juntendo University School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan
| | - Masahiro Enomoto
- Division of Signaling Biology, Ontario Cancer Institute, Toronto, ON, Canada M5G 1L7
| | - Katsuhiko Mikoshiba
- 1] Laboratory for Developmental Neurobiology, RIKEN Brain Science Institute, Saitama 351-0198, Japan [2] Calcium Oscillation Project, International Cooperative Research Project and Solution-Oriented Research for Science and Technology, Japan Science and Technology Agency, Kawaguchi, Saitama 332-0012, Japan
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40
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Bayer-Santos E, Lima FM, Ruiz JC, Almeida IC, da Silveira JF. Characterization of the small RNA content of Trypanosoma cruzi extracellular vesicles. Mol Biochem Parasitol 2014; 193:71-4. [PMID: 24583081 DOI: 10.1016/j.molbiopara.2014.02.004] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2013] [Revised: 02/11/2014] [Accepted: 02/15/2014] [Indexed: 12/19/2022]
Abstract
A growing body of evidence in mammalian cells indicates that secreted vesicles can be used to mediate intercellular communication processes by transferring various bioactive molecules, including mRNAs and microRNAs. Based on these findings, we decided to analyze whether Trypanosoma cruzi-derived extracellular vesicles contain RNA molecules and performed a deep sequencing and genome-wide analysis of a size-fractioned cDNA library (16-40nt) from extracellular vesicles secreted by noninfective epimastigote and infective metacyclic trypomastigote forms. Our data show that the small RNAs contained in these extracellular vesicles originate from multiple sources, including tRNAs. In addition, our results reveal that the variety and expression of small RNAs are different between parasite stages, suggesting diverse functions. Taken together, these observations call attention to the potential regulatory functions that these RNAs might play once transferred between parasites and/or to mammalian host cells.
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Affiliation(s)
- Ethel Bayer-Santos
- Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo, São Paulo SP 04023-062, Brazil; Border Biomedical Research Center, Department of Biological Sciences, University of Texas at El Paso, El Paso, TX 79968, USA
| | - Fábio Mitsuo Lima
- Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo, São Paulo SP 04023-062, Brazil
| | | | - Igor C Almeida
- Border Biomedical Research Center, Department of Biological Sciences, University of Texas at El Paso, El Paso, TX 79968, USA.
| | - José Franco da Silveira
- Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo, São Paulo SP 04023-062, Brazil.
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A pre- and co-knockdown of RNAseT enzyme, Eri-1, enhances the efficiency of RNAi induced gene silencing in Caenorhabditis elegans. PLoS One 2014; 9:e87635. [PMID: 24475317 PMCID: PMC3901743 DOI: 10.1371/journal.pone.0087635] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2013] [Accepted: 12/28/2013] [Indexed: 01/08/2023] Open
Abstract
Background The approach of RNAi mediated gene knockdown, employing exogenous dsRNA, is being beneficially exploited in various fields of functional genomics. The immense utility of the approach came to fore from studies with model system C. elegans, but quickly became applicable with varied research models ranging from in vitro to various in vivo systems. Previously, there have been reports on the refractoriness of the neuronal cells to RNAi mediated gene silencing following which several modulators like eri-1 and lin-15 were described in C. elegans which, when present, would negatively impact the gene knockdown. Methodology/Principal Findings Taking a clue from these findings, we went on to screen hypothesis-driven- methodologies towards exploring the efficiency in the process of RNAi under various experimental conditions, wherein these genes would be knocked down preceding to, or concurrently with, the knocking down of a gene of interest. For determining the efficiency of gene knockdown, we chose to study visually stark phenotypes of uncoordinated movement, dumpy body morphology and blistered cuticle obtained by knocking down of genes unc-73, dpy-9 and bli-3 respectively, employing the RNAi-by-feeding protocol in model system C. elegans. Conclusions/Significance Our studies led to a very interesting outcome as the results reveal that amongst various methods tested, pre-incubation with eri-1 dsRNA synthesizing bacteria followed by co-incubation with eri-1 and gene-of-interest dsRNA synthesizing bacteria leads to the most efficient gene silencing as observed by the analysis of marker phenotypes. This provides an approach for effectively employing RNAi induced gene silencing while working with different genetic backgrounds including transgenic and mutant strains.
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43
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Li J, Yuan J, Cheng KCC, Inglese J, Su XZ. Chemical genomics for studying parasite gene function and interaction. Trends Parasitol 2013; 29:603-11. [PMID: 24215777 DOI: 10.1016/j.pt.2013.10.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Revised: 10/08/2013] [Accepted: 10/08/2013] [Indexed: 12/20/2022]
Abstract
With the development of new technologies in genome sequencing, gene expression profiling, genotyping, and high-throughput screening of chemical compound libraries, small molecules are playing increasingly important roles in studying gene expression regulation, gene-gene interaction, and gene function. Here we briefly review and discuss some recent advancements in drug target identification and phenotype characterization using combinations of high-throughput screening of small-molecule libraries and various genome-wide methods such as whole-genome sequencing, genome-wide association studies (GWAS), and genome-wide expression analysis. These approaches can be used to search for new drugs against parasite infections, to identify drug targets or drug resistance genes, and to infer gene function.
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Affiliation(s)
- Jian Li
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, Fujian 361005, P.R. China
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Rubio MAT, Paris Z, Gaston KW, Fleming IMC, Sample P, Trotta CR, Alfonzo JD. Unusual noncanonical intron editing is important for tRNA splicing in Trypanosoma brucei. Mol Cell 2013; 52:184-92. [PMID: 24095278 DOI: 10.1016/j.molcel.2013.08.042] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2013] [Revised: 07/16/2013] [Accepted: 08/20/2013] [Indexed: 02/01/2023]
Abstract
In cells, tRNAs are synthesized as precursor molecules bearing extra sequences at their 5' and 3' ends. Some tRNAs also contain introns, which, in archaea and eukaryotes, are cleaved by an evolutionarily conserved endonuclease complex that generates fully functional mature tRNAs. In addition, tRNAs undergo numerous posttranscriptional nucleotide chemical modifications. In Trypanosoma brucei, the single intron-containing tRNA (tRNA(Tyr)GUA) is responsible for decoding all tyrosine codons; therefore, intron removal is essential for viability. Using molecular and biochemical approaches, we show the presence of several noncanonical editing events, within the intron of pre-tRNA(Tyr)GUA, involving guanosine-to-adenosine transitions (G to A) and an adenosine-to-uridine transversion (A to U). The RNA editing described here is required for proper processing of the intron, establishing the functional significance of noncanonical editing with implications for tRNA processing in the deeply divergent kinetoplastid lineage and eukaryotes in general.
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Affiliation(s)
- Mary Anne T Rubio
- Department of Microbiology and The Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA
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Target-based drug discovery for human African trypanosomiasis: selection of molecular target and chemical matter. Parasitology 2013; 141:28-36. [PMID: 23931634 PMCID: PMC3884840 DOI: 10.1017/s0031182013001017] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Target-based approaches for human African trypanosomiasis (HAT) and related parasites can be a valuable route for drug discovery for these diseases. However, care needs to be taken in selection of both the actual drug target and the chemical matter that is developed. In this article, potential criteria to aid target selection are described. Then the physiochemical properties of typical oral drugs are discussed and compared to those of known anti-parasitics.
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46
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Choudhury R, Tsai YS, Dominguez D, Wang Y, Wang Z. Engineering RNA endonucleases with customized sequence specificities. Nat Commun 2013; 3:1147. [PMID: 23093184 PMCID: PMC3612931 DOI: 10.1038/ncomms2154] [Citation(s) in RCA: 81] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2012] [Accepted: 09/21/2012] [Indexed: 01/16/2023] Open
Abstract
Specific cleavage of RNAs is critical for in vitro manipulation of RNA and for in vivo gene silencing. Here we engineer artificial site-specific RNA endonucleases (ASREs) to function analogously to DNA restriction enzymes. We combine a general RNA cleavage domain with a series of Pumilio/FBF (PUF) domains that specifically recognize different 8-nt RNA sequences. The resulting ASREs specifically recognize RNA substrates and efficiently cleave near their binding sites. ASREs can be devised to recognize and cleave various RNA target sequences, providing a useful tool to manipulate RNAs in vitro. In addition, we generate designer ASREs to specifically silence an endogenous gene in E. coli, as well as a mitochondrial-encoded gene in human cells, suggesting that ASREs can serve as a gene silencing tool with designed specificity.
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Affiliation(s)
- Rajarshi Choudhury
- Department of Pharmacology and Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
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Zhang H, Ehrenkaufer GM, Hall N, Singh U. Small RNA pyrosequencing in the protozoan parasite Entamoeba histolytica reveals strain-specific small RNAs that target virulence genes. BMC Genomics 2013; 14:53. [PMID: 23347563 PMCID: PMC3610107 DOI: 10.1186/1471-2164-14-53] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2012] [Accepted: 01/02/2013] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Small RNA mediated gene silencing is a well-conserved regulatory pathway. In the parasite Entamoeba histolytica an endogenous RNAi pathway exists, however, the depth and diversity of the small RNA population remains unknown. RESULTS To characterize the small RNA population that associates with E. histolytica Argonaute-2 (EhAGO2-2), we immunoprecipitated small RNAs that associate with it and performed one full pyrosequencing run. Data analysis revealed new features of the 27nt small RNAs including the 5'-G predominance, distinct small RNA distribution patterns on protein coding genes, small RNAs mapping to both introns and exon-exon junctions, and small RNA targeted genes that are clustered particularly in sections of genome duplication. Characterization of genomic loci to which both sense and antisense small RNAs mapped showed that both sets of small RNAs have 5'-polyphosphate termini; strand-specific RT-PCR detected transcripts in both directions at these loci suggesting that both transcripts may serve as template for small RNA generation. In order to determine whether small RNA abundance patterns account for strain-specific gene expression profiles of E. histolytica virulent and non-virulent strains, we sequenced small RNAs from a non-virulent strain and found that small RNAs mapped to genes in a manner consistent with their regulation of strain-specific virulence genes. CONCLUSIONS We provided a full spectrum analysis for E. histolytica AGO2-2 associated 27nt small RNAs. Additionally, comparative analysis of small RNA populations from virulent and non-virulent amebic strains indicates that small RNA populations may regulate virulence genes.
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Affiliation(s)
- Hanbang Zhang
- Division of Infectious Diseases, Department of Internal Medicine, Stanford University School of Medicine, Stanford, California 94305-5107, USA
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Katoch R, Thakur N. Advances in RNA interference technology and its impact on nutritional improvement, disease and insect control in plants. Appl Biochem Biotechnol 2013; 169:1579-605. [PMID: 23322250 DOI: 10.1007/s12010-012-0046-5] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2012] [Accepted: 12/17/2012] [Indexed: 12/11/2022]
Abstract
This review highlights the advances in the knowledge of RNA interference (RNAi) and discusses recent progress on the functionality of different components RNAi machinery operating in the organisms. The silencing of genes by RNA interference has become the technology of choice for investigation of gene functions in different organisms. The refinement in the knowledge of the endogenous RNAi pathways in plants along with the development of new strategies and applications for the improvement of nutritional value of important agricultural crops through suppression of genes in different plants have opened new vistas for nutritional security. The improvement in the nutritional status of the plants and reduction in the level of toxins or antinutrients was desired for long, but the available technology was not completely successful in achieving the tissue specific regulation of some genes. In the recent years, a number of economically important crop plants have been tested successfully for improving plant nutritional value through metabolic engineering using RNAi. The implications of this technology for crop improvement programs, including nutritional enrichment, reduction of antinutrients, disease, and insect control have been successfully tested in variety of crops with commercial considerations. The enhancement of the nutraceutical traits for the desired health benefits in common crop plants through manipulation of gene expression has been elaborated in this article. The tremendous potential with RNAi technology is expected to revolutionize the modern agriculture for meeting the growing challenges is discussed.
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Affiliation(s)
- Rajan Katoch
- Biochemistry Laboratory, Department of Crop Improvement, College of Agriculture, CSK Himachal Pradesh Krishi Vishvavidyalaya, Palampur, India 176062.
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Disruption of the expression of a non-coding RNA significantly impairs cellular differentiation in Toxoplasma gondii. Int J Mol Sci 2012; 14:611-24. [PMID: 23275028 PMCID: PMC3565285 DOI: 10.3390/ijms14010611] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2012] [Revised: 12/14/2012] [Accepted: 12/18/2012] [Indexed: 11/17/2022] Open
Abstract
The protozoan parasite Toxoplasma gondii is an important human and veterinary pathogen. Asexual replication of T. gondii in humans and intermediate hosts is characterized by two forms: rapidly growing “tachyzoites” and latent “bradyzoite” tissue cysts. Tachyzoites are responsible for acute illness and congenital neurological birth defects, while the more slowly dividing bradyzoite form can remain latent within the tissues for many years, representing a threat to immunocompromised patients. We have developed a genetic screen to identify regulatory genes that control parasite differentiation and have isolated mutants that fail to convert to bradyzoites. One of these mutants has an insertion disrupting a locus that encodes a developmentally regulated non-coding RNA transcript, named Tg-ncRNA-1. Microarray hybridizations suggest that Tg-ncRNA-1 is involved in the early steps of bradyzoite differentiation. Since Tg-ncRNA-1 does not contain an open reading frame, we used the algorithm Coding Potential Calculator (CPC) that evaluates the protein-coding potential of a transcript, to classify Tg-ncRNA-1. The CPC results strongly indicate that Tg-ncRNA-1 is a non-coding RNA (ncRNA). Interestingly, a previously generated mutant also contains an insertion in Tg-ncRNA-1. We show that both mutants have a decreased ability to form bradyzoites, and complementation of both mutants with wild-type Tg-ncRNA-1 restores the ability of the parasites to differentiate. It has been shown that an important part of bradyzoite differentiation is transcriptionally controlled, but this is the first time that a non-coding RNA is implicated in this process.
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Mukherjee K, Campos H, Kolaczkowski B. Evolution of animal and plant dicers: early parallel duplications and recurrent adaptation of antiviral RNA binding in plants. Mol Biol Evol 2012. [PMID: 23180579 PMCID: PMC3563972 DOI: 10.1093/molbev/mss263] [Citation(s) in RCA: 113] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
RNA interference (RNAi) is a eukaryotic molecular system that serves two primary functions: 1) gene regulation and 2) protection against selfish elements such as viruses and transposable DNA. Although the biochemistry of RNAi has been detailed in model organisms, very little is known about the broad-scale patterns and forces that have shaped RNAi evolution. Here, we provide a comprehensive evolutionary analysis of the Dicer protein family, which carries out the initial RNA recognition and processing steps in the RNAi pathway. We show that Dicer genes duplicated and diversified independently in early animal and plant evolution, coincident with the origins of multicellularity. We identify a strong signature of long-term protein-coding adaptation that has continually reshaped the RNA-binding pocket of the plant Dicer responsible for antiviral immunity, suggesting an evolutionary arms race with viral factors. We also identify key changes in Dicer domain architecture and sequence leading to specialization in either gene-regulatory or protective functions in animal and plant paralogs. As a whole, these results reveal a dynamic picture in which the evolution of Dicer function has driven elaboration of parallel RNAi functional pathways in animals and plants.
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Affiliation(s)
- Krishanu Mukherjee
- Department of Microbiology & Cell Science, University of Florida, FL, USA.
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