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Diffendall G, Scherf A. Deciphering the Plasmodium falciparum perinuclear var gene expression site. Trends Parasitol 2024; 40:707-716. [PMID: 38910098 DOI: 10.1016/j.pt.2024.06.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2024] [Revised: 06/03/2024] [Accepted: 06/03/2024] [Indexed: 06/25/2024]
Abstract
The protozoan parasite Plasmodium falciparum, responsible for the deadliest form of human malaria, employs antigenic variation via monoallelic expression as a key survival strategy. The selective activation of one out of the 60-member var gene family is key to understanding the parasite's ability to cause severe disease and evade the host immune response. var gene activation is initiated by its relocation to a specialized expression site. While the perinuclear expression site (PES) plays a crucial role in enabling the expression of a single allele, the characteristics of this PES remain largely obscure. Recent breakthroughs in genome editing tools and the discovery of regulatory noncoding RNAs have shed light on this intriguing biological feature, offering significant insights into the mechanisms of pathogen virulence.
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Affiliation(s)
- Gretchen Diffendall
- Institut Pasteur, Universite Paris Cité, INSERM U1201, CNRS EMR9195, Paris, France
| | - Artur Scherf
- Institut Pasteur, Universite Paris Cité, INSERM U1201, CNRS EMR9195, Paris, France.
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2
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Diffendall G, Claes A, Barcons-Simon A, Nyarko P, Dingli F, Santos MM, Loew D, Claessens A, Scherf A. RNA polymerase III is involved in regulating Plasmodium falciparum virulence. eLife 2024; 13:RP95879. [PMID: 38921824 PMCID: PMC11208047 DOI: 10.7554/elife.95879] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/27/2024] Open
Abstract
While often undetected and untreated, persistent seasonal asymptomatic malaria infections remain a global public health problem. Despite the presence of parasites in the peripheral blood, no symptoms develop. Disease severity is correlated with the levels of infected red blood cells (iRBCs) adhering within blood vessels. Changes in iRBC adhesion capacity have been linked to seasonal asymptomatic malaria infections, however how this is occurring is still unknown. Here, we present evidence that RNA polymerase III (RNA Pol III) transcription in Plasmodium falciparum is downregulated in field isolates obtained from asymptomatic individuals during the dry season. Through experiments with in vitro cultured parasites, we have uncovered an RNA Pol III-dependent mechanism that controls pathogen proliferation and expression of a major virulence factor in response to external stimuli. Our findings establish a connection between P. falciparum cytoadhesion and a non-coding RNA family transcribed by Pol III. Additionally, we have identified P. falciparum Maf1 as a pivotal regulator of Pol III transcription, both for maintaining cellular homeostasis and for responding adaptively to external signals. These results introduce a novel perspective that contributes to our understanding of P. falciparum virulence. Furthermore, they establish a connection between this regulatory process and the occurrence of seasonal asymptomatic malaria infections.
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Affiliation(s)
- Gretchen Diffendall
- Institut Pasteur, Universite Paris CitéParisFrance
- Institut Pasteur, Sorbonne Université Ecole doctorale Complexité du VivantParisFrance
| | | | - Anna Barcons-Simon
- Institut Pasteur, Universite Paris CitéParisFrance
- Institut Pasteur, Sorbonne Université Ecole doctorale Complexité du VivantParisFrance
- Institut Pasteur, Biomedical Center, Division of Physiological Chemistry, Faculty of Medicine, Ludwig-Maximilians-Universität MünchenMunichGermany
| | - Prince Nyarko
- Institut Pasteur, Laboratory of Pathogen-Host Interaction (LPHI), CNRS, University of MontpellierMontpellierFrance
| | - Florent Dingli
- Institut Pasteur, Institut Curie, PSL Research University, Centre de Recherche, CurieCoreTech Mass Spectrometry ProteomicsParisFrance
| | - Miguel M Santos
- Institut Pasteur, Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina da Universidade de LisboaLisboaPortugal
| | - Damarys Loew
- Institut Pasteur, Institut Curie, PSL Research University, Centre de Recherche, CurieCoreTech Mass Spectrometry ProteomicsParisFrance
| | - Antoine Claessens
- Institut Pasteur, Laboratory of Pathogen-Host Interaction (LPHI), CNRS, University of MontpellierMontpellierFrance
- Institut Pasteur, LPHI, MIVEGEC, CNRS, INSERM, University of MontpellierMontpellierFrance
| | - Artur Scherf
- Institut Pasteur, Universite Paris CitéParisFrance
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3
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Lin L, Liu Y, Liang R, Guo Y, Xu R, Fan R, Jiao Z, Zhao W, Yue L, Lu M, Liu S, Su XZ, Li J. Size-dependent enhancement of gene expression by Plasmodium 5'UTR introns. Parasit Vectors 2024; 17:238. [PMID: 38802937 PMCID: PMC11131223 DOI: 10.1186/s13071-024-06319-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Accepted: 05/03/2024] [Indexed: 05/29/2024] Open
Abstract
BACKGROUND Eukaryotic genes contain introns that are removed by the spliceosomal machinery during mRNA maturation. Introns impose a huge energetic burden on a cell; therefore, they must play an essential role in maintaining genome stability and/or regulating gene expression. Many genes (> 50%) in Plasmodium parasites contain predicted introns, including introns in 5' and 3' untranslated regions (UTR). However, the roles of UTR introns in the gene expression of malaria parasites remain unknown. METHODS In this study, an episomal dual-luciferase assay was developed to evaluate gene expression driven by promoters with or without a 5'UTR intron from four Plasmodium yoelii genes. To investigate the effect of the 5'UTR intron on endogenous gene expression, the pytctp gene was tagged with 3xHA at the N-terminal of the coding region, and parasites with or without the 5'UTR intron were generated using the CRISPR/Cas9 system. RESULTS We showed that promoters with 5'UTR introns had higher activities in driving gene expression than those without 5'UTR introns. The results were confirmed in recombinant parasites expressing an HA-tagged gene (pytctp) driven by promoter with or without 5'UTR intron. The enhancement of gene expression was intron size dependent, but not the DNA sequence, e.g. the longer the intron, the higher levels of expression. Similar results were observed when a promoter from one strain of P. yoelii was introduced into different parasite strains. Finally, the 5'UTR introns were alternatively spliced in different parasite development stages, suggesting an active mechanism employed by the parasites to regulate gene expression in various developmental stages. CONCLUSIONS Plasmodium 5'UTR introns enhance gene expression in a size-dependent manner; the presence of alternatively spliced mRNAs in different parasite developmental stages suggests that alternative slicing of 5'UTR introns is one of the key mechanisms in regulating parasite gene expression and differentiation.
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Affiliation(s)
- Lirong Lin
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiamen, 361102, Fujian, China
| | - Yanjing Liu
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiamen, 361102, Fujian, China
| | - Rui Liang
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiamen, 361102, Fujian, China
| | - Yue Guo
- School of Medicine, Huzhou University, Huzhou, 313000, Zhejiang, China
| | - Ruixue Xu
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiamen, 361102, Fujian, China
| | - Ruoxi Fan
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiamen, 361102, Fujian, China
| | - Zhiwei Jiao
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiamen, 361102, Fujian, China
| | - Wenting Zhao
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiamen, 361102, Fujian, China
| | - Lixia Yue
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiamen, 361102, Fujian, China
| | - Mingke Lu
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiamen, 361102, Fujian, China
| | - Shengfa Liu
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiamen, 361102, Fujian, China
| | - Xin-Zhuan Su
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, 20850, USA.
| | - Jian Li
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiamen, 361102, Fujian, China.
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4
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Kioko M, Pance A, Mwangi S, Goulding D, Kemp A, Rono M, Ochola-Oyier LI, Bull PC, Bejon P, Rayner JC, Abdi AI. Extracellular vesicles could be a putative posttranscriptional regulatory mechanism that shapes intracellular RNA levels in Plasmodium falciparum. Nat Commun 2023; 14:6447. [PMID: 37833314 PMCID: PMC10575976 DOI: 10.1038/s41467-023-42103-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Accepted: 09/26/2023] [Indexed: 10/15/2023] Open
Abstract
Plasmodium falciparum secretes extracellular vesicles (PfEVs) that contain parasite-derived RNA. However, the significance of the secreted RNA remains unexplored. Here, we compare secreted and intracellular RNA from asexual cultures of six P. falciparum lines. We find that secretion of RNA via extracellular vesicles is not only periodic throughout the asexual intraerythrocytic developmental cycle but is also highly conserved across P. falciparum isolates. We further demonstrate that the phases of RNA secreted via extracellular vesicles are discernibly shifted compared to those of the intracellular RNA within the secreting whole parasite. Finally, transcripts of genes with no known function during the asexual intraerythrocytic developmental cycle are enriched in PfEVs compared to the whole parasite. We conclude that the secretion of extracellular vesicles could be a putative posttranscriptional RNA regulation mechanism that is part of or synergise the classic RNA decay processes to maintain intracellular RNA levels in P. falciparum.
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Affiliation(s)
- Mwikali Kioko
- Bioscience Department, KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
- Open University, Milton Keynes, UK
| | - Alena Pance
- Pathogens and Microbes Programme, Wellcome Sanger Institute, Cambridge, UK
- School of Life and Medical Science, University of Hertfordshire, Hatfield, UK
| | - Shaban Mwangi
- Bioscience Department, KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
| | - David Goulding
- Pathogens and Microbes Programme, Wellcome Sanger Institute, Cambridge, UK
| | - Alison Kemp
- Cambridge Institute of Medical Research, University of Cambridge, Cambridge, UK
| | - Martin Rono
- Bioscience Department, KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
- Pwani University Biosciences Research Centre, Pwani University, Kilifi, Kenya
| | | | - Pete C Bull
- Bioscience Department, KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Philip Bejon
- Bioscience Department, KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Julian C Rayner
- Cambridge Institute of Medical Research, University of Cambridge, Cambridge, UK
| | - Abdirahman I Abdi
- Bioscience Department, KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya.
- Pwani University Biosciences Research Centre, Pwani University, Kilifi, Kenya.
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
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5
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Thompson TA, Chahine Z, Le Roch KG. The role of long noncoding RNAs in malaria parasites. Trends Parasitol 2023; 39:517-531. [PMID: 37121862 DOI: 10.1016/j.pt.2023.03.016] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 03/16/2023] [Accepted: 03/18/2023] [Indexed: 05/02/2023]
Abstract
The human malaria parasites, including Plasmodium falciparum, persist as a major cause of global morbidity and mortality. The recent stalling of progress toward malaria elimination substantiates a need for novel interventions. Controlled gene expression is central to the parasite's numerous life cycle transformations and adaptation. With few specific transcription factors (TFs) identified, crucial roles for chromatin states and epigenetics in parasite transcription have become evident. Although many chromatin-modifying enzymes are known, less is known about which factors mediate their impacts on transcriptional variation. Like those of higher eukaryotes, long noncoding RNAs (lncRNAs) have recently been shown to have integral roles in parasite gene regulation. This review aims to summarize recent developments and key findings on the role of lncRNAs in P. falciparum.
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Affiliation(s)
- Trevor A Thompson
- Department of Molecular, Cell and Systems Biology, University of California Riverside, CA, USA
| | - Zeinab Chahine
- Department of Molecular, Cell and Systems Biology, University of California Riverside, CA, USA
| | - Karine G Le Roch
- Department of Molecular, Cell and Systems Biology, University of California Riverside, CA, USA.
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6
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Prabhu SR, Ware AP, Umakanth S, Hande M, Mahabala C, Saadi AV, Satyamoorthy K. Erythrocyte miRNA-92a-3p interactions with PfEMP1 as determinants of clinical malaria. Funct Integr Genomics 2023; 23:93. [PMID: 36941394 PMCID: PMC10027640 DOI: 10.1007/s10142-023-01028-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Revised: 03/06/2023] [Accepted: 03/13/2023] [Indexed: 03/22/2023]
Abstract
Based on the recently added high throughput analysis data on small noncoding RNAs in modulating disease pathophysiology of malaria, we performed an integrative computational analysis for exploring the role of human-host erythrocytic microRNAs (miRNAs) and their influence on parasite survival and host homeostasis. An in silico analysis was performed on transcriptomic datasets accessed from PlasmoDB and Gene Expression Omnibus (GEO) repositories analyzed using miRanda, miRTarBase, mirDIP, and miRDB to identify the candidate miRNAs that were further subjected to network analysis using MCODE and DAVID. This was followed by immune infiltration analysis and screening for RNA degradation mechanisms. Seven erythrocytic miRNAs, miR-451a, miR-92a-3p, miR-16-5p, miR-142-3p, miR-15b-5p, miR-19b-3p, and miR-223-3p showed favourable interactions with parasite genes expressed during blood stage infection. The miR-92a-3p that targeted the virulence gene PfEMP1 showed drastic reduction during infection. Performing pathway analysis for the human-host gene targets for the miRNA identified TOB1, TOB2, CNOT4, and XRN1 genes that are associated to RNA degradation processes, with the exoribonuclease XRN1, highly enriched in the malarial samples. On evaluating the role of exoribonucleases in miRNA degradation further, the pattern of Plasmodium falciparum_XRN1 showed increased levels during infection thus suggesting a defensive role for parasite survival. This study identifies miR-92a-3p, a member of C13orf25/ miR-17-92 cluster, as a novel miRNA inhibitor of the crucial parasite genes responsible for symptomatic malaria. Evidence for a plausible link to chromosome 13q31.3 loci controlling the epigenetic disease regulation is also suggested.
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Affiliation(s)
- Sowmya R Prabhu
- Department of Biotechnology, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal, Karnataka, 576104, India
| | - Akshay Pramod Ware
- Department of Bioinformatics, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal, Karnataka, 576104, India
| | - Shashikiran Umakanth
- Department of Medicine, Dr. TMA Pai Hospital, Manipal Academy of Higher Education, Manipal, Karnataka, 576104, India
| | - Manjunath Hande
- Department of Medicine, Kasturba Medical College, Manipal Academy of Higher Education, Manipal, Karnataka, 576104, India
| | - Chakrapani Mahabala
- Department of Medicine, Kasturba Medical College, Mangalore, Manipal Academy of Higher Education, Manipal, Karnataka, 576104, India
| | - Abdul Vahab Saadi
- Department of Biotechnology, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal, Karnataka, 576104, India
| | - Kapaettu Satyamoorthy
- Department of Cell and Molecular Biology, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal, Karnataka, 576104, India.
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7
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Diffendall GM, Barcons-Simon A, Baumgarten S, Dingli F, Loew D, Scherf A. Discovery of RUF6 ncRNA-interacting proteins involved in P. falciparum immune evasion. Life Sci Alliance 2022; 6:6/1/e202201577. [PMID: 36379669 PMCID: PMC9670795 DOI: 10.26508/lsa.202201577] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 10/25/2022] [Accepted: 10/26/2022] [Indexed: 11/16/2022] Open
Abstract
Non-coding RNAs (ncRNAs) are emerging regulators of immune evasion and transmission of Plasmodium falciparum RUF6 is an ncRNA gene family that is transcribed by RNA polymerase III but actively regulates the Pol II-transcribed var virulence gene family. Understanding how RUF6 ncRNA connects to downstream effectors is lacking. We developed an RNA-directed proteomic discovery (ChIRP-MS) protocol to identify in vivo RUF6 ncRNA-protein interactions. The RUF6 ncRNA interactome was purified with biotinylated antisense oligonucleotides. Quantitative label-free mass spectrometry identified several unique proteins linked to gene transcription including RNA Pol II subunits, nucleosome assembly proteins, and a homologue of DEAD box helicase 5 (DDX5). Affinity purification of Pf-DDX5 identified proteins originally found by our RUF6-ChIRP protocol, validating the technique's robustness for identifying ncRNA interactomes in P. falciparum Inducible displacement of nuclear Pf-DDX5 resulted in significant down-regulation of the active var gene. Our work identifies a RUF6 ncRNA-protein complex that interacts with RNA Pol II to sustain the var gene expression, including a helicase that may resolve G-quadruplex secondary structures in var genes to facilitate transcriptional activation and progression.
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Affiliation(s)
- Gretchen M Diffendall
- Universite Paris Cité, Institut Pasteur, Biology of Host-Parasite Interactions Unit, INSERM U1201, CNRS EMR9195, Paris, France,Sorbonne Université Ecole doctorale Complexité du Vivant ED515, Paris, France
| | - Anna Barcons-Simon
- Universite Paris Cité, Institut Pasteur, Biology of Host-Parasite Interactions Unit, INSERM U1201, CNRS EMR9195, Paris, France,Sorbonne Université Ecole doctorale Complexité du Vivant ED515, Paris, France,Biomedical Center, Division of Physiological Chemistry, Faculty of Medicine, Ludwig-Maximilians-Universität München, Munich, Germany
| | | | - Florent Dingli
- Institut Curie, PSL Research University, Centre de Recherche, CurieCoreTech Mass Spectrometry Proteomics, Paris, France
| | - Damarys Loew
- Institut Curie, PSL Research University, Centre de Recherche, CurieCoreTech Mass Spectrometry Proteomics, Paris, France
| | - Artur Scherf
- Universite Paris Cité, Institut Pasteur, Biology of Host-Parasite Interactions Unit, INSERM U1201, CNRS EMR9195, Paris, France
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8
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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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9
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Boonyalai N, Kirativanich K, Thamnurak C, Praditpol C, Vesely BA, Wojnarski M, Griesenbeck JS, Waters NC. A single point mutation in the Plasmodium falciparum 3'-5' exonuclease does not alter piperaquine susceptibility. Malar J 2022; 21:130. [PMID: 35459163 PMCID: PMC9034581 DOI: 10.1186/s12936-022-04148-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Accepted: 03/31/2022] [Indexed: 12/03/2022] Open
Abstract
Background The rise in Plasmodium falciparum resistance to dihydroartemisinin–piperaquine (DHA–PPQ) treatment has been documented in the Greater Mekong Subregion with associations with mutations in the P. falciparum chloroquine resistance transporter (pfcrt) and plasmepsin 2 (pfpm2) genes. However, it is unclear whether other genes also play a role with PPQ resistance, such as the E415G mutation in the exonuclease (pfexo) gene. The aim of this study was to investigate the role of this mutation in PPQ resistance by generating transgenic parasites expressing the pfexo-E415G mutant allele. Methods Transgenic parasite clones carrying the E415G mutation in PfEXO of the B5 isolate were derived by CRISPR-Cas9 gene editing and verified using PCR and gene sequencing. Polymorphisms of pfkelch-13, pfcrt, and pfexo were examined by PCR while the copy number variations of pfpm2 were examined by both relative quantitative real-time PCR and the duplication breakpoint assay. Drug sensitivity against a panel of antimalarials, the ring-stage survival assay (RSA), the PPQ survival assay (PSA), and bimodal dose-response curves were used to evaluate antimalarial susceptibility. Results The transgenic line, B5-rexo-E415G-B8, was successfully generated. The PPQ-IC90, %PPQ survival, and the bimodal dose-response clearly showed that E415G mutation in PfEXO of B5 isolate remained fully susceptible to PPQ. Furthermore, growth assays demonstrated that the engineered parasites grew slightly faster than the unmodified parental isolates whereas P. falciparum isolates harbouring pfkelch-13, pfcrt, and pfexo mutations with multiple copies of pfpm2 grew much more slowly. Conclusions Insertion of the E415G mutation in PfEXO did not lead to increased PPQ-IC90 and %PPQ survival, suggesting that this mutation alone may not be associated with PPQ resistance, but could still be an important marker if used in conjunction with other markers for monitoring PPQ-resistant parasites. The results also highlight the importance of monitoring and evaluating suspected genetic mutations with regard to parasite fitness and resistance. Supplementary information The online version contains supplementary material available at 10.1186/s12936-022-04148-z.
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Affiliation(s)
- Nonlawat Boonyalai
- Department of Bacterial and Parasitic Diseases, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand.
| | - Kirakarn Kirativanich
- Department of Bacterial and Parasitic Diseases, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Chatchadaporn Thamnurak
- Department of Bacterial and Parasitic Diseases, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Chantida Praditpol
- Department of Bacterial and Parasitic Diseases, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Brian A Vesely
- Department of Bacterial and Parasitic Diseases, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Mariusz Wojnarski
- Department of Bacterial and Parasitic Diseases, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - John S Griesenbeck
- Department of Bacterial and Parasitic Diseases, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Norman C Waters
- Department of Bacterial and Parasitic Diseases, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
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10
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Shang X, Wang C, Shen L, Sheng F, He X, Wang F, Fan Y, He X, Jiang M. PfAP2-EXP2, an Essential Transcription Factor for the Intraerythrocytic Development of Plasmodium falciparum. Front Cell Dev Biol 2022; 9:782293. [PMID: 35083215 PMCID: PMC8785209 DOI: 10.3389/fcell.2021.782293] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Accepted: 12/09/2021] [Indexed: 12/13/2022] Open
Abstract
Plasmodium falciparum undergoes a series of asexual replications in human erythrocytes after infection, which are effective targets for combatting malaria. Here, we report roles of an ApiAP2 transcription factor PfAP2-EXP2 (PF3D7_0611200) in the intraerythrocytic developmental cycle of P. falciparum. PfAP2-EXP2 conditional knockdown resulted in an asexual growth defect but without an appreciable effect on parasite morphology. Further ChIP-seq analysis revealed that PfAP2-EXP2 targeted genes related to virulence and interaction between erythrocytes and parasites. Especially, PfAP2-EXP2 regulation of euchromatic genes does not depend on recognizing specific DNA sequences, while a CCCTAAACCC motif is found in its heterochromatic binding sites. Combined with transcriptome profiling, we suggest that PfAP2-EXP2 is participated in the intraerythrocytic development by affecting the expression of genes related to cell remodeling at the schizont stage. In summary, this study explores an ApiAP2 member plays an important role for the P. falciparum blood-stage replication, which suggests a new perspective for malaria elimination.
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Affiliation(s)
- Xiaomin Shang
- Department of Medical Genetics, Shanghai Tenth People's Hospital, School of Medicine, Tongji University, Shanghai, China.,Department of Parasitology, Xiangya School of Medicine, Central South University, Changsha, China
| | - Changhong Wang
- Department of Medical Genetics, Shanghai Tenth People's Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Li Shen
- Department of Medical Genetics, Shanghai Tenth People's Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Fei Sheng
- Department of Medical Genetics, Shanghai Tenth People's Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Xiaohui He
- Department of Medical Genetics, Shanghai Tenth People's Hospital, School of Medicine, Tongji University, Shanghai, China.,National Health Commission Key Laboratory of Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, China
| | - Fei Wang
- Department of Medical Genetics, Shanghai Tenth People's Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Yanting Fan
- Department of Medical Genetics, Shanghai Tenth People's Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Xiaoqin He
- National Health Commission Key Laboratory of Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, China
| | - Mei Jiang
- Department of Medical Genetics, Shanghai Tenth People's Hospital, School of Medicine, Tongji University, Shanghai, China
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11
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Shang X, Wang C, Fan Y, Guo G, Wang F, Zhao Y, Sheng F, Tang J, He X, Yu X, Zhang M, Zhu G, Yin S, Mu J, Culleton R, Cao J, Jiang M, Zhang Q. OUP accepted manuscript. Nucleic Acids Res 2022; 50:3413-3431. [PMID: 35288749 PMCID: PMC8989538 DOI: 10.1093/nar/gkac176] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 03/03/2022] [Accepted: 03/05/2022] [Indexed: 11/13/2022] Open
Abstract
Heterochromatin-associated gene silencing controls multiple physiological processes in malaria parasites, however, little is known concerning the regulatory network and cis-acting sequences involved in the organization of heterochromatin and how they modulate heterochromatic gene expression. Based on systematic profiling of genome-wide occupancy of eighteen Apicomplexan AP2 transcription factors by ChIP-seq analysis, we identify and characterize eight heterochromatin-associated factors (PfAP2-HFs), which exhibit preferential enrichment within heterochromatic regions but with differential coverage profiles. Although these ApiAP2s target euchromatic gene loci via specific DNA motifs, they are likely integral components of heterochromatin independent of DNA motif recognition. Systematic knockout screenings of ApiAP2 factors coupled with RNA-seq transcriptomic profiling revealed three activators and three repressors of heterochromatic gene expression including four PfAP2-HFs. Notably, expression of virulence genes is either completely silenced or significantly reduced upon the depletion of PfAP2-HC. Integrated multi-omics analyses reveal autoregulation and feed-forward loops to be common features of the ApiAP2 regulatory network, in addition to the occurrence of dynamic interplay between local chromatin structure and ApiAP2s in transcriptional control. Collectively, this study provides a valuable resource describing the genome-wide landscape of the ApiAP2 family and insights into functional divergence and cooperation within this family during the blood-stage development of malaria parasites.
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Affiliation(s)
| | | | | | | | - Fei Wang
- Laboratory of Molecular Parasitology, Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration of Ministry of Education, Tongji Hospital; Clinical Center for Brain and Spinal Cord Research, School of Medicine, Tongji University, Shanghai 200092, China
| | - Yuemeng Zhao
- Laboratory of Molecular Parasitology, Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration of Ministry of Education, Tongji Hospital; Clinical Center for Brain and Spinal Cord Research, School of Medicine, Tongji University, Shanghai 200092, China
| | - Fei Sheng
- Laboratory of Molecular Parasitology, Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration of Ministry of Education, Tongji Hospital; Clinical Center for Brain and Spinal Cord Research, School of Medicine, Tongji University, Shanghai 200092, China
| | - Jianxia Tang
- National Health Commission Key Laboratory of Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, 214064, China
| | - Xiaoqin He
- National Health Commission Key Laboratory of Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, 214064, China
| | - Xinyu Yu
- National Health Commission Key Laboratory of Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, 214064, China
| | - Meihua Zhang
- National Health Commission Key Laboratory of Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, 214064, China
| | - Guoding Zhu
- National Health Commission Key Laboratory of Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, 214064, China
| | - Shigang Yin
- Laboratory of Neurological Diseases and Brain Function, The Affiliated Hospital of Southwest Medical University, Luzhou, China
| | - Jianbing Mu
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20892-8132, USA
| | - Richard Culleton
- Division of Molecular Parasitology, Proteo-Science Centre, Ehime University, Matsuyama, Ehime 790-8577, Japan
| | - Jun Cao
- Correspondence may also be addressed to Jun Cao. Tel: +05 10 6878 1007;
| | - Mei Jiang
- Correspondence may also be addressed to Mei Jiang. Tel: +86 21 6598 5138;
| | - Qingfeng Zhang
- To whom correspondence should be addressed. Tel: +86 21 6598 5138;
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12
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Mitesser V, Dzikowski R. Resetting var Gene Transcription in Plasmodium falciparum. Methods Mol Biol 2022; 2470:211-220. [PMID: 35881348 DOI: 10.1007/978-1-0716-2189-9_16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
One of the key mechanisms contributing to the virulence of Plasmodium falciparum is its ability to undergo antigenic switching among antigenically distinct variants of the PfEMP1 adhesive proteins, encoded by the var gene family. To avoid premature exposure of its antigenic repertoire, the parasite transcribes its var genes in a mutually exclusive manner, and switch expression at a very slow rate. This process is epigenetically regulated and it relies on "epigenetic memory," which imprints the single active var gene to remain active for multiple replication cycles. Erasing this epigenetic memory in parasites grown in culture resembles parasites, which egress from the liver. It could therefore be of interest for investigating var switching patterns at the onset of malaria infections. In addition, this procedure could be used for creating heterogeneity of var expression among parasite populations. The methodology described here for resetting of var gene expression is based on promoter titration, also known as molecular sponging.
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Affiliation(s)
- Vera Mitesser
- Department of Microbiology and Molecular Genetics, The Institute for Medical Research Israel-Canada, The Kuvin Center for the Study of Infectious and Tropical Diseases, Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Ron Dzikowski
- Department of Microbiology and Molecular Genetics, The Institute for Medical Research Israel-Canada, The Kuvin Center for the Study of Infectious and Tropical Diseases, Hebrew University-Hadassah Medical School, Jerusalem, Israel.
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13
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Shang X, Shen S, Tang J, He X, Zhao Y, Wang C, He X, Guo G, Liu M, Wang L, Zhu Q, Yang G, Jiang C, Zhang M, Yu X, Han J, Culleton R, Jiang L, Cao J, Gu L, Zhang Q. A cascade of transcriptional repression determines sexual commitment and development in Plasmodium falciparum. Nucleic Acids Res 2021; 49:9264-9279. [PMID: 34365503 PMCID: PMC8450074 DOI: 10.1093/nar/gkab683] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 07/25/2021] [Accepted: 07/28/2021] [Indexed: 11/12/2022] Open
Abstract
Gametocytogenesis, the process by which malaria parasites produce sexual forms that can infect mosquitoes, is essential for the transmission of malaria. A transcriptional switch of the pfap2-g gene triggers sexual commitment, but how the complex multi-step process is precisely programed remains largely unknown. Here, by systematic functional screening of a panel of ApiAP2 transcription factors, we identify six new ApiAP2 members associated with gametocytogenesis in Plasmodium falciparum. Among these, PfAP2-G5 (PF3D7_1139300) was found to be indispensable for gametocytogenesis. This factor suppresses the transcriptional activity of the pfap2-g gene via binding to both the upstream region and exonic gene body, the latter is linked to the maintenance of local heterochromatin structure, thereby preventing initiation of sexual commitment. Removal of this repressive effect through pfap2-g5 knockout disrupts the asexual replication cycle and promotes sexual commitment accompanied by upregulation of pfap2-g expression. However, the gametocytes produced fail to mature fully. Further analyses show that PfAP2-G5 is essential for gametocyte maturation, and causes the down-regulation of pfap2-g and a set of early gametocyte genes activated by PfAP2-G prior to gametocyte development. Collectively, our findings reveal a regulation cascade of gametocyte production in malaria parasites, and provide a new target for transmission blocking interventions.
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Affiliation(s)
- Xiaomin Shang
- Laboratory of Molecular Parasitology, Research Center for Translational Medicine, Key Laboratory of Arrhythmias of the Ministry of Education of China, East Hospital, School of Medicine, Tongji University, Shanghai 200120, China
| | - Shijun Shen
- Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration of Ministry of Education, Orthopaedic Department of Tongji Hospital, Shanghai Key Laboratory of Signaling and Disease Research, the School of Life Sciences and Technology, Tongji University, Shanghai 200092, China
| | - Jianxia Tang
- National Health Commission Key Laboratory of Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi 214064, China
| | - Xiaoqin He
- National Health Commission Key Laboratory of Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi 214064, China
| | - Yuemeng Zhao
- Laboratory of Molecular Parasitology, Research Center for Translational Medicine, Key Laboratory of Arrhythmias of the Ministry of Education of China, East Hospital, School of Medicine, Tongji University, Shanghai 200120, China.,Unit of Human Parasite Molecular and Cell Biology, Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Changhong Wang
- Laboratory of Molecular Parasitology, Research Center for Translational Medicine, Key Laboratory of Arrhythmias of the Ministry of Education of China, East Hospital, School of Medicine, Tongji University, Shanghai 200120, China
| | - Xiaohui He
- Laboratory of Molecular Parasitology, Research Center for Translational Medicine, Key Laboratory of Arrhythmias of the Ministry of Education of China, East Hospital, School of Medicine, Tongji University, Shanghai 200120, China
| | - Gangqiang Guo
- Laboratory of Molecular Parasitology, Research Center for Translational Medicine, Key Laboratory of Arrhythmias of the Ministry of Education of China, East Hospital, School of Medicine, Tongji University, Shanghai 200120, China.,Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration of Ministry of Education, Orthopaedic Department of Tongji Hospital, Shanghai Key Laboratory of Signaling and Disease Research, the School of Life Sciences and Technology, Tongji University, Shanghai 200092, China
| | - Meng Liu
- Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration of Ministry of Education, Orthopaedic Department of Tongji Hospital, Shanghai Key Laboratory of Signaling and Disease Research, the School of Life Sciences and Technology, Tongji University, Shanghai 200092, China
| | - Liping Wang
- Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration of Ministry of Education, Orthopaedic Department of Tongji Hospital, Shanghai Key Laboratory of Signaling and Disease Research, the School of Life Sciences and Technology, Tongji University, Shanghai 200092, China
| | - Qianshu Zhu
- Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration of Ministry of Education, Orthopaedic Department of Tongji Hospital, Shanghai Key Laboratory of Signaling and Disease Research, the School of Life Sciences and Technology, Tongji University, Shanghai 200092, China
| | - Guang Yang
- Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration of Ministry of Education, Orthopaedic Department of Tongji Hospital, Shanghai Key Laboratory of Signaling and Disease Research, the School of Life Sciences and Technology, Tongji University, Shanghai 200092, China
| | - Cizhong Jiang
- Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration of Ministry of Education, Orthopaedic Department of Tongji Hospital, Shanghai Key Laboratory of Signaling and Disease Research, the School of Life Sciences and Technology, Tongji University, Shanghai 200092, China
| | - Meihua Zhang
- National Health Commission Key Laboratory of Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi 214064, China
| | - Xinyu Yu
- National Health Commission Key Laboratory of Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi 214064, China
| | - Jiping Han
- Unit of Human Parasite Molecular and Cell Biology, Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Richard Culleton
- Division of Molecular Parasitology, Proteo-Science Centre, Ehime University, Matsuyama, Ehime 790-8577, Japan.,Department of Protozoology, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan
| | - Lubin Jiang
- Unit of Human Parasite Molecular and Cell Biology, Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Jun Cao
- National Health Commission Key Laboratory of Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi 214064, China.,Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing 211166, China.,Public Health Research Center, Jiangnan University, Wuxi 214122, China
| | - Liang Gu
- Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration of Ministry of Education, Orthopaedic Department of Tongji Hospital, Shanghai Key Laboratory of Signaling and Disease Research, the School of Life Sciences and Technology, Tongji University, Shanghai 200092, China
| | - Qingfeng Zhang
- Laboratory of Molecular Parasitology, Research Center for Translational Medicine, Key Laboratory of Arrhythmias of the Ministry of Education of China, East Hospital, School of Medicine, Tongji University, Shanghai 200120, China
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14
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Alvarez DR, Ospina A, Barwell T, Zheng B, Dey A, Li C, Basu S, Shi X, Kadri S, Chakrabarti K. The RNA structurome in the asexual blood stages of malaria pathogen plasmodium falciparum. RNA Biol 2021; 18:2480-2497. [PMID: 33960872 DOI: 10.1080/15476286.2021.1926747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
Plasmodium falciparum is a deadly human pathogen responsible for the devastating disease called malaria. In this study, we measured the differential accumulation of RNA secondary structures in coding and non-coding transcripts from the asexual developmental cycle in P. falciparum in human red blood cells. Our comprehensive analysis that combined high-throughput nuclease mapping of RNA structures by duplex RNA-seq, SHAPE-directed RNA structure validation, immunoaffinity purification and characterization of antisense RNAs collectively measured differentially base-paired RNA regions throughout the parasite's asexual RBC cycle. Our mapping data not only aligned to a diverse pool of RNAs with known structures but also enabled us to identify new structural RNA regions in the malaria genome. On average, approximately 71% of the genes with secondary structures are found to be protein coding mRNAs. The mapping pattern of these base-paired RNAs corresponded to all regions of mRNAs, including the 5' UTR, CDS and 3' UTR as well as the start and stop codons. Histone family genes which are known to form secondary structures in their mRNAs and transcripts from genes which are important for transcriptional and post-transcriptional control, such as the unique plant-like transcription factor family, ApiAP2, DNA-/RNA-binding protein, Alba3 and proteins important for RBC invasion and malaria cytoadherence also showed strong accumulation of duplex RNA reads in various asexual stages in P. falciparum. Intriguingly, our study determined stage-specific, dynamic relationships between mRNA structural contents and translation efficiency in P. falciparum asexual blood stages, suggesting an essential role of RNA structural changes in malaria gene expression programs.
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Affiliation(s)
- Diana Renteria Alvarez
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, North Carolina, USA
| | - Alejandra Ospina
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, North Carolina, USA
| | - Tiffany Barwell
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, North Carolina, USA
| | - Bo Zheng
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, North Carolina, USA
| | - Abhishek Dey
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, North Carolina, USA
| | - Chong Li
- Temple University, Philadelphia, PA, USA
| | - Shrabani Basu
- Division of Medical Genetics, Children's Hospital of Pittsburgh of UPMC, Pittsburgh, PA, USA
| | | | - Sabah Kadri
- Division of Health and Biomedical Informatics, Northwestern University Feinberg School of Medicine and Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, IL, USA
| | - Kausik Chakrabarti
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, North Carolina, USA
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15
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Ikeda M, Hirai M, Tachibana SI, Mori T, Mita T. Isolation of Mutants With Reduced Susceptibility to Piperaquine From a Mutator of the Rodent Malaria Parasite Plasmodium berghei. Front Cell Infect Microbiol 2021; 11:672691. [PMID: 34222045 PMCID: PMC8242943 DOI: 10.3389/fcimb.2021.672691] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Accepted: 04/19/2021] [Indexed: 12/13/2022] Open
Abstract
Elucidation of the mechanisms of drug resistance in malaria parasites is crucial for combatting the emergence and spread of resistant parasites, which can be achieved by tracing resistance-associated mutations and providing useful information for drug development. Previously, we produced a novel genetic tool, a Plasmodium berghei mutator (PbMut), whose base substitution rate is 36.5 times higher than that of wild-type parasites. Here, we report the isolation of a mutant with reduced susceptibility to piperaquine (PPQ) from PbMut under PPQ pressure by sequential nine-cycle screening and named it PbMut-PPQ-R-P9. The ED50 of PbMut-PPQ-R-P9 was 1.79 times higher than that of wild-type parasites, suggesting that its PPQ resistance is weak. In the 1st screen, recrudescence occurred in the mice infected with PbMut but not in those infected with wild-type parasites, suggesting earlier emergence of PPQ-resistant parasites from PbMut. Whole-genome sequence analysis of PbMut-PPQ-R-P9 clones revealed that eight nonsynonymous mutations were conserved in all clones, including N331I in PbCRT, the gene encoding chloroquine resistance transporter (CRT). The PbCRT(N331I) mutation already existed in the parasite population after the 2nd screen and was predominant in the population after the 8th screen. An artificially inserted PbCRT(N331I) mutation gave rise to reduced PPQ susceptibility in genome-edited parasites (PbCRT-N331I). The PPQ susceptibility and growth rates of PbCRT-N331I parasites were significantly lower than those of PbMut-PPQ-R-P9, implying that additional mutations in the PbMut-PPQ-R9 parasites could compensate for the fitness cost of the PbCRT(N331I) mutation and contribute to reduced PPQ susceptibility. In summary, PbMut could serve as a novel genetic tool for predicting gene mutations responsible for drug resistance. Further study on PbMut-PPQ-R-P9 could identify genetic changes that compensate for fitness costs owing to drug resistance acquisition.
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Affiliation(s)
| | - Makoto Hirai
- *Correspondence: Makoto Hirai, ; Toshihiro Mita,
| | | | | | - Toshihiro Mita
- Department of Tropical Medicine and Parasitology, Faculty of Medicine, Juntendo University, Tokyo, Japan
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16
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Role of chromatin modulation in the establishment of protozoan parasite infection for developing targeted chemotherapeutics. THE NUCLEUS 2021. [DOI: 10.1007/s13237-021-00356-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
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17
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The Architectural Factor HMGB1 Is Involved in Genome Organization in the Human Malaria Parasite Plasmodium falciparum. mBio 2021; 12:mBio.00148-21. [PMID: 33906919 PMCID: PMC8092211 DOI: 10.1128/mbio.00148-21] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The three-dimensional (3D) genome organization plays a critical role in the regulation of gene expression in eukaryotic organisms. In the unicellular malaria parasite Plasmodium falciparum, the high-order chromosome organization has emerged as an important epigenetic pathway mediating gene expression, particularly for virulence genes, but the related architectural factors and underlying mechanism remain elusive. Herein, we have identified the high-mobility-group protein HMGB1 as a critical architectural factor for maintenance of genome organization in P. falciparum Genome-wide occupancy analysis (chromatin immunoprecipitation sequencing [ChIP-seq]) shows that the HMGB1 protein is recruited mainly to centromeric regions likely via a DNA-binding-independent pathway. Chromosome conformation capture coupled with next-generation sequencing (Hi-C-seq) and 3D modeling analysis show that the loss of HMGB1 disrupts the integrity of centromere/telomere-based chromosome organization accompanied with diminished interaction frequency among centromere clusters. This triggers local chromatin alteration and dysregulated gene expression. Notably, the entire repertoire of the primary virulence genes (var) was completely silenced in the absence of P. falciparum HMGB1 (PfHMGB1). Furthermore, the disrupted nuclear organization was reconstituted by complementation of HMGB1, thereby rescuing the mutually exclusive expression of the var gene family. Collectively, these data demonstrate that the architectural factor HMGB1 is associated with gene expression via mediating the high-order structure of genome organization. This finding not only contributes better understanding of the epigenetic regulation of gene expression but may also provide novel targets for antimalarial strategies.IMPORTANCE Malaria remains a major public health and economic burden currently. The mutually exclusive expression of the virulence genes is associated with the pathogenesis and immune evasion of human malaria parasites in the host. The nuclear architecture provides a well-organized environment for differential gene expression in the nucleus, but the underlying mechanism remains largely unknown. In this study, we have identified the highly conserved high-mobility-group protein HMGB1 as a key architecture regulator involved in virulence gene expression by establishing high-order genome organization in the nucleus of P. falciparum Mechanistic investigation revealed that the specific interaction of HMGB1 and centromeres constructed the precisely organized nuclear architecture, which coordinated with local chromatin structure to control the singular expression of virulence genes. Hence, this protein appears to be a critical architectural regulator for the pathogenesis of malaria infection and may be a new target for the development of an intervention strategy against malaria.
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18
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Xu Y, Qiao D, Wen Y, Bi Y, Chen Y, Huang Z, Cui L, Guo J, Cao Y. PfAP2-G2 Is Associated to Production and Maturation of Gametocytes in Plasmodium falciparum via Regulating the Expression of PfMDV-1. Front Microbiol 2021; 11:631444. [PMID: 33537025 PMCID: PMC7848025 DOI: 10.3389/fmicb.2020.631444] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Accepted: 12/21/2020] [Indexed: 11/13/2022] Open
Abstract
Gametocyte is the sole form of the Plasmodium falciparum which is transmissible to the mosquito vector. Here, we report that an Apicomplexan Apetala2 (ApiAP2) family transcription factor, PfAP2-G2 (Pf3D7_1408200), plays a role in the development of gametocytes in P. falciparum by regulating the expression of PfMDV-1 (Pf3D7_1216500). Reverse transcriptase-quantitative PCR (RT-qPCR) analysis showed that PfAP2-G2 was highly expressed in the ring stage. Indirect immunofluorescence assay showed nuclear localization of PfAP2-G2 in asexual stages. The knockout of PfAP2-G2 led to a ~95% decrease in the number of mature gametocytes with a more substantial influence on the production and maturation of the male gametocytes, resulting in a higher female/male gametocyte ratio. To test the mechanism of this phenotype, RNA-seq and RT-qPCR showed that disruption of PfAP2-G2 led to the down-regulation of male development gene-1 (PfMDV-1) in asexual stages. We further found that PfAP2-G2 was enriched at the transcriptional start site (TSS) of PfMDV-1 by chromatin immunoprecipitation and qPCR assay in both ring stage and schizont stage, which demonstrated that PfMDV-1 is one of the targets of PfAP2-G2. In addition, RT-qPCR also showed that PfAP2-G (Pf3D7_1222600), the master regulator for sexual commitment, was also down-regulated in the PfAP2-G2 knockout parasites in the schizont stage, but no change in the ring stage. This phenomenon suggested that PfAP2-G2 played a role at the asexual stage for the development of parasite gametocytes and warrants further investigations in regulatory pathways of PfAP2-G2.
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Affiliation(s)
- Yaozheng Xu
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, China
| | - Dan Qiao
- Department of Laboratory Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yuhao Wen
- Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, China
| | - Yifei Bi
- Philosophy, Politics and Economics Department, University College London, London, United Kingdom
| | - Yuxi Chen
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, China
| | - Zhenghui Huang
- Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, China
| | - Liwang Cui
- Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL, United States
| | - Jian Guo
- Department of Laboratory Medicine, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, China
| | - Yaming Cao
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, China
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19
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Briquet S, Marinach C, Silvie O, Vaquero C. Preparing for Transmission: Gene Regulation in Plasmodium Sporozoites. Front Cell Infect Microbiol 2021; 10:618430. [PMID: 33585284 PMCID: PMC7878544 DOI: 10.3389/fcimb.2020.618430] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Accepted: 12/16/2020] [Indexed: 11/13/2022] Open
Abstract
Plasmodium sporozoites are transmitted to mammals by anopheline mosquitoes and first infect the liver, where they transform into replicative exoerythrocytic forms, which subsequently release thousands of merozoites that invade erythrocytes and initiate the malaria disease. In some species, sporozoites can transform into dormant hypnozoites in the liver, which cause malaria relapses upon reactivation. Transmission from the insect vector to a mammalian host is a critical step of the parasite life cycle, and requires tightly regulated gene expression. Sporozoites are formed inside oocysts in the mosquito midgut and become fully infectious after colonization of the insect salivary glands, where they remain quiescent until transmission. Parasite maturation into infectious sporozoites is associated with reprogramming of the sporozoite transcriptome and proteome, which depends on multiple layers of transcriptional and post-transcriptional regulatory mechanisms. An emerging scheme is that gene expression in Plasmodium sporozoites is controlled by alternating waves of transcription activity and translational repression, which shape the parasite RNA and protein repertoires for successful transition from the mosquito vector to the mammalian host.
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Affiliation(s)
- Sylvie Briquet
- Centre d'Immunologie et des Maladies Infectieuses, INSERM, CNRS, Sorbonne Université, Paris, France
| | - Carine Marinach
- Centre d'Immunologie et des Maladies Infectieuses, INSERM, CNRS, Sorbonne Université, Paris, France
| | - Olivier Silvie
- Centre d'Immunologie et des Maladies Infectieuses, INSERM, CNRS, Sorbonne Université, Paris, France
| | - Catherine Vaquero
- Centre d'Immunologie et des Maladies Infectieuses, INSERM, CNRS, Sorbonne Université, Paris, France
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20
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Liu H, Cui XY, Xu DD, Wang F, Meng LW, Zhao YM, Liu M, Shen SJ, He XH, Fang Q, Tao ZY, Jiang CZ, Zhang QF, Gu L, Xia H. Actin-related protein Arp4 regulates euchromatic gene expression and development through H2A.Z deposition in blood-stage Plasmodium falciparum. Parasit Vectors 2020; 13:314. [PMID: 32552779 PMCID: PMC7301494 DOI: 10.1186/s13071-020-04139-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Accepted: 05/21/2020] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Malaria caused by Plasmodium spp. is still a major threat to public health globally. The various approaches to developing new antimalarial agents rely on the understanding of the complex regulatory mechanisms of dynamic gene expression in the life-cycle of these malaria parasites. The nuclear members of the evolutionarily conserved actin-related protein nuclear (ARP) superfamily are the major components of nucleosome remodelling complexes. In the human malaria parasite Plasmodium falciparum, bioinformatics analysis has predicted three ARP orthologues: PfArp1, PfArp4 and PfArp6. However, little is known about the biological functions of putative PfArp4. In this study, we aimed to investigate the function and the underlying mechanisms of PfArp4 gene regulation. METHODS A conditional gene knockdown approach was adopted by incorporating the glucosamine-inducible glmS ribozyme sequence into the 3' UTR of the PfArp4 and PfArp6 genes. The transgenic parasites PfArp4-Ty1-Ribo, PfArp6-Ty1-Ribo and pL6-PfArp4-Ty1::PfArp6-HA were generated by the CRISPR-Cas9 technique. The knockdown effect in the transgenic parasite was measured by growth curve assay and western blot (WB) analysis. The direct interaction between PfArp4 and PfArp6 was validated by co-IFA and co-IP assays. The euchromatic gene expression mediated through H2A.Z (histone H2A variant) deposition and H3K9ac modification at promoters and regulated by PfArp4, was determined by RNA-seq and ChIP-seq. RESULTS The inducible knockdown of PfArp4 inhibited blood-stage development of P. falciparum. PfArp4 and PfArp6 were colocalized in the nucleus of P. falciparum parasites. PfArp4 gene knockdown altered the global transcriptome. PfArp4 protein colocalized with the histone variant H2A.Z and euchromatic marker H3K9ac in intergenic regions. The inducible downregulation of PfArp4 resulted in the depletion of H2A.Z and lower H3K9ac levels at the upstream regions of eukaryotic genes, thereby repressing the transcriptional abundance of H2A.Z-dependent genes. CONCLUSIONS Our findings suggest that PfArp4 regulates the cell cycle by controlling H2A.Z deposition and affecting centromere function, contributing to the understanding the complex epigenetic regulation of gene expression and the development of P. falciparum.
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Affiliation(s)
- Hui Liu
- Department of Microbiology and Parasitology, Bengbu Medical College, Bengbu, 233030, China
| | - Xin-Yu Cui
- The School of Life Sciences and Technology, Tongji University, Shanghai, 200092, China
| | - Dan-Dan Xu
- Department of Microbiology and Parasitology, Bengbu Medical College, Bengbu, 233030, China
| | - Fei Wang
- Research Center for Translational Medicine, Key Laboratory of Arrhythmias of the Ministry of Education of China, East Hospital, Tongji University School of Medicine, Shanghai, 200120, China
| | - Lin-Wen Meng
- Department of Microbiology and Parasitology, Bengbu Medical College, Bengbu, 233030, China
| | - Yue-Meng Zhao
- Research Center for Translational Medicine, Key Laboratory of Arrhythmias of the Ministry of Education of China, East Hospital, Tongji University School of Medicine, Shanghai, 200120, China
| | - Meng Liu
- The School of Life Sciences and Technology, Tongji University, Shanghai, 200092, China
| | - Shi-Jun Shen
- The School of Life Sciences and Technology, Tongji University, Shanghai, 200092, China
| | - Xiao-Hui He
- Research Center for Translational Medicine, Key Laboratory of Arrhythmias of the Ministry of Education of China, East Hospital, Tongji University School of Medicine, Shanghai, 200120, China
| | - Qiang Fang
- Department of Microbiology and Parasitology, Bengbu Medical College, Bengbu, 233030, China.,Anhui Provincial Key Laboratory of Infection and Immunology, Bengbu Medical College, Bengbu, 233000, China
| | - Zhi-Yong Tao
- Department of Microbiology and Parasitology, Bengbu Medical College, Bengbu, 233030, China
| | - Ci-Zong Jiang
- The School of Life Sciences and Technology, Tongji University, Shanghai, 200092, China.,Tsingtao Advanced Research Institute, Tongji University, Qingdao, 266071, China
| | - Qing-Feng Zhang
- Research Center for Translational Medicine, Key Laboratory of Arrhythmias of the Ministry of Education of China, East Hospital, Tongji University School of Medicine, Shanghai, 200120, China
| | - Liang Gu
- The School of Life Sciences and Technology, Tongji University, Shanghai, 200092, China.
| | - Hui Xia
- Department of Microbiology and Parasitology, Bengbu Medical College, Bengbu, 233030, China. .,Anhui Provincial Key Laboratory of Infection and Immunology, Bengbu Medical College, Bengbu, 233000, China.
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21
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Abstract
Malaria remains a major public health and economic burden. The heterochromatin environment controls the silencing of genes associated with the fate of malaria parasites. Previous studies have demonstrated that a group of GC-rich ncRNAs (RUF6) is associated with the mutually exclusive expression of var genes, but the underlying mechanisms remain elusive. Here, through a series of genetic manipulation and genome-wide multiomics analysis, we have identified the plasmodial orthologue of RNA exosome-associated Rrp6 as an upstream regulator of RUF6 expression and revealed that the dysregulation of RUF6 upon Rrp6 knockdown triggered local chromatin alteration, thereby activating most heterochromatic genes via direct interaction of RUF6 and distal gene loci. This finding not only uncovered the in-depth mechanism of RUF6-mediated regulation of heterochromatic genes but also identified Rrp6 as a novel regulator of gene expression in human malaria parasites, which provides a new target for developing intervention strategies against malaria. The heterochromatin environment plays a central role in silencing genes associated with the malaria parasite’s development, survival in the host, and transmission to the mosquito vector. However, the underlying mechanism regulating the dynamic chromatin structure is not understood yet. Here, we have uncovered that Plasmodium falciparum Rrp6, an orthologue of eukaryotic RNA exosome-associated RNase, controls the silencing of heterochromatic genes. PfRrp6 knockdown disrupted the singular expression of the GC-rich ncRNA RUF6 family, a known critical regulator of virulence gene expression, through the stabilization of the nascent transcripts. Mechanistic investigation showed that the accumulation of the multiple RUF6 ncRNAs triggered local chromatin remodeling in situ, which activated their adjacent var genes. Strikingly, chromatin isolation by RNA purification analysis (ChIRP-seq) revealed that a remarkable RUF6 ncRNA had interacted with distal heterochromatin regions directly and stimulated a global derepression effect on heterochromatic genes, including all variant gene families and the sexual commitment-associated regulator ap2-g gene. Collectively, Rrp6 appears to conduct the epigenetic surveillance of heterochromatic gene expression through controlling RUF6 levels, thereby securing antigenic variation and sexual commitment of malaria parasites during the infection of the host.
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22
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Llorà-Batlle O, Michel-Todó L, Witmer K, Toda H, Fernández-Becerra C, Baum J, Cortés A. Conditional expression of PfAP2-G for controlled massive sexual conversion in Plasmodium falciparum. SCIENCE ADVANCES 2020; 6:eaaz5057. [PMID: 32577509 PMCID: PMC7286680 DOI: 10.1126/sciadv.aaz5057] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2019] [Accepted: 04/15/2020] [Indexed: 05/19/2023]
Abstract
Malaria transmission requires that some asexual parasites convert into sexual forms termed gametocytes. The initial stages of sexual development, including sexually committed schizonts and sexual rings, remain poorly characterized, mainly because they are morphologically identical to their asexual counterparts and only a small subset of parasites undergo sexual development. Here, we describe a system for controlled sexual conversion in the human malaria parasite Plasmodium falciparum, based on conditional expression of the PfAP2-G transcription factor. Using this system, ~90 percent of the parasites converted into sexual forms upon induction, enabling the characterization of committed and early sexual stages without further purification. We characterized sexually committed schizonts and sexual rings at the transcriptomic and phenotypic levels, which revealed down-regulation of genes involved in solute transport upon sexual commitment, among other findings. The new inducible lines will facilitate the study of early sexual stages at additional levels, including multiomic characterization and drug susceptibility assays.
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Affiliation(s)
- Oriol Llorà-Batlle
- ISGlobal, Hospital Clinic–Universitat de Barcelona, Barcelona 08036, Catalonia, Spain
| | - Lucas Michel-Todó
- ISGlobal, Hospital Clinic–Universitat de Barcelona, Barcelona 08036, Catalonia, Spain
| | - Kathrin Witmer
- Department of Life Sciences, Imperial College London, London, SW7 2AZ, UK
| | - Haruka Toda
- ISGlobal, Hospital Clinic–Universitat de Barcelona, Barcelona 08036, Catalonia, Spain
| | - Carmen Fernández-Becerra
- ISGlobal, Hospital Clinic–Universitat de Barcelona, Barcelona 08036, Catalonia, Spain
- IGTP Institut d’Investigació Germans Trias i Pujol, Badalona 08916, Catalonia, Spain
| | - Jake Baum
- Department of Life Sciences, Imperial College London, London, SW7 2AZ, UK
| | - Alfred Cortés
- ISGlobal, Hospital Clinic–Universitat de Barcelona, Barcelona 08036, Catalonia, Spain
- ICREA, Barcelona 08010, Catalonia, Spain
- Corresponding author.
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23
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Llorà-Batlle O, Tintó-Font E, Cortés A. Transcriptional variation in malaria parasites: why and how. Brief Funct Genomics 2020; 18:329-341. [PMID: 31114839 DOI: 10.1093/bfgp/elz009] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Revised: 02/04/2019] [Accepted: 04/10/2019] [Indexed: 12/24/2022] Open
Abstract
Transcriptional differences enable the generation of alternative phenotypes from the same genome. In malaria parasites, transcriptional plasticity plays a major role in the process of adaptation to fluctuations in the environment. Multiple studies with culture-adapted parasites and field isolates are starting to unravel the different transcriptional alternatives available to Plasmodium falciparum and the underlying molecular mechanisms. Here we discuss how epigenetic variation, directed transcriptional responses and also genetic changes that affect transcript levels can all contribute to transcriptional variation and, ultimately, parasite survival. Some transcriptional changes are driven by stochastic events. These changes can occur spontaneously, resulting in heterogeneity within parasite populations that provides the grounds for adaptation by dynamic natural selection. However, transcriptional changes can also occur in response to external cues. A better understanding of the mechanisms that the parasite has evolved to alter its transcriptome may ultimately contribute to the design of strategies to combat malaria to which the parasite cannot adapt.
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Affiliation(s)
- Oriol Llorà-Batlle
- ISGlobal, Hospital Clínic - Universitat de Barcelona, 08036 Barcelona, Catalonia, Spain
| | - Elisabet Tintó-Font
- ISGlobal, Hospital Clínic - Universitat de Barcelona, 08036 Barcelona, Catalonia, Spain
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24
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Yin S, Fan Y, He X, Wei G, Wen Y, Zhao Y, Shi M, Wei J, Chen H, Han J, Jiang L, Zhang Q. The cryptic unstable transcripts are associated with developmentally regulated gene expression in blood-stage Plasmodium falciparum. RNA Biol 2020; 17:828-842. [PMID: 32079470 DOI: 10.1080/15476286.2020.1732032] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Abstract
The tight gene expression regulation controls the development and pathogenesis of human malaria parasite Plasmodium falciparum throughout the complex life cycle. Recent studies have revealed the pervasive nascent transcripts in the genome of P. falciparum, suggesting the existence of a hidden transcriptome involved in the dynamic gene expression. However, the landscape and related biological functions of nascent non-coding RNAs (ns-ncRNAs) are still poorly explored. Here we profiled the transcription dynamics of nascent RNAs by rRNA-depleted and stranded RNA sequencing over the course of 48-h intraerythrocytic developmental cycle (IDC). We identified the genome-wide sources of a total of 2252 ns-ncRNAs, mostly originating from intergenic and untranslated regions of annotated genes. By integrating the nascent RNA abundances with ATAC-seq and ChIP-seq analysis, we uncovered the euchromatic microenvironment surrounding the ns-ncRNA loci, and revealed a positive correlation between ns-ncRNAs and corresponding mRNA abundances. Finally, by gene knock-down strategy, we showed that the cooperation of RNA exosome catalytic subunit PfDis3 and PfMtr4 cofactor played a major role in ns-ncRNAs degradation. Collectively, this study contributes to understanding of the potential roles of short-lived nascent ncRNAs in regulating gene expression in malaria parasites.
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Affiliation(s)
- Shigang Yin
- Research Center for Translational Medicine, Key Laboratory of Arrhythmias of the Ministry of Education of China, East Hospital, Tongji University School of Medicine , Shanghai, China.,Unit of Human Parasite Molecular and Cell Biology, Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, University of Chinese Academy of Sciences, Chinese Academy of Sciences , Shanghai, China.,Laboratory of Nervous System Disease and Brain Functions, The Affiliated Hospital of Southwest Medical University , Luzhou, China.,Academician (Expert) Workstation of Sichuan Province, The Affiliated Hospital of Southwest Medical University , Luzhou, China
| | - Yanting Fan
- Research Center for Translational Medicine, Key Laboratory of Arrhythmias of the Ministry of Education of China, East Hospital, Tongji University School of Medicine , Shanghai, China
| | - Xiaohui He
- Research Center for Translational Medicine, Key Laboratory of Arrhythmias of the Ministry of Education of China, East Hospital, Tongji University School of Medicine , Shanghai, China
| | - Guiying Wei
- Research Center for Translational Medicine, Key Laboratory of Arrhythmias of the Ministry of Education of China, East Hospital, Tongji University School of Medicine , Shanghai, China
| | - Yuhao Wen
- Unit of Human Parasite Molecular and Cell Biology, Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, University of Chinese Academy of Sciences, Chinese Academy of Sciences , Shanghai, China
| | - Yuemeng Zhao
- Research Center for Translational Medicine, Key Laboratory of Arrhythmias of the Ministry of Education of China, East Hospital, Tongji University School of Medicine , Shanghai, China
| | - Mingli Shi
- Unit of Human Parasite Molecular and Cell Biology, Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, University of Chinese Academy of Sciences, Chinese Academy of Sciences , Shanghai, China
| | - Jieqiong Wei
- Unit of Human Parasite Molecular and Cell Biology, Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, University of Chinese Academy of Sciences, Chinese Academy of Sciences , Shanghai, China
| | - Huiling Chen
- Unit of Human Parasite Molecular and Cell Biology, Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, University of Chinese Academy of Sciences, Chinese Academy of Sciences , Shanghai, China
| | - Jiping Han
- Unit of Human Parasite Molecular and Cell Biology, Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, University of Chinese Academy of Sciences, Chinese Academy of Sciences , Shanghai, China
| | - Lubin Jiang
- Unit of Human Parasite Molecular and Cell Biology, Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, University of Chinese Academy of Sciences, Chinese Academy of Sciences , Shanghai, China.,China School of Life Science and Technology, ShanghaiTech University , Shanghai, China
| | - Qingfeng Zhang
- Research Center for Translational Medicine, Key Laboratory of Arrhythmias of the Ministry of Education of China, East Hospital, Tongji University School of Medicine , Shanghai, China
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25
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Wang WF, Zhang YL. PfSWIB, a potential chromatin regulator for var gene regulation and parasite development in Plasmodium falciparum. Parasit Vectors 2020; 13:48. [PMID: 32019597 PMCID: PMC7001229 DOI: 10.1186/s13071-020-3918-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Accepted: 01/29/2020] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Various transcription factors are involved in the process of mutually exclusive expression and clonal variation of the Plasmodium multigene (var) family. Recent studies revealed that a P. falciparum SWI/SNF-related matrix-associated actin-dependent regulator of chromatin (PfSWIB) might trigger stage-specific programmed cell death (PCD), and was not only crucial for the survival and development of parasite, but also had profound effects on the parasite by interacting with other unknown proteins. However, it remains unclear whether PfSIWB is involved in transcriptional regulation of this virulence gene and its functional properties. METHODS A conditional knockdown system "PfSWIB-FKBP-LID" was introduced to the parasite clone 3D7, and an integrated parasite line "PfSWIB-HA-FKBP-LID" was obtained by drug cycling and clone screening. Growth curve analysis (GCA) was performed to investigate the growth and development of different parasite lines during 96 h in vitro culturing, by assessing parasitemia. Finally, we performed qPCR assays to detect var gene expression profiling in various comparison groups, as well as the mutually exclusive expression pattern of the var genes within a single 48 h life-cycle of P. falciparum in different parasite lines. In addition, RNA-seq was applied to analyze the var gene expression in different lines. RESULTS GCA revealed that conditional knockdown of PfSWIB could interfere with the growth and development of P. falciparum. The parasitemia of PfSWIB∆ showed a significant decline at 96 h during in vitro culture compared with the PfSWIB and 3D7 lines (P < 0.0001). qPCR and RNA-seq analysis confirmed that depletion of PfSWIB not only silences upsA, upsC and partial upsB var genes, as well as removes the silencing of partial upsB var genes at the ring stage in PfSWIB∆ line, but also leads to aberrant expression of upsA and partial upsB/upsC var genes at the mature stage of P. falciparum, during a single 48-h life-cycle. CONCLUSIONS We demonstrated that PfSWIB was involved in the process of clonal variation in var gene expression, and crucial for the survival and development of Plasmodium parasite. These findings could provide better understanding of the mechanism and function of PfSWIB contributing to the pathogenesis in malaria parasites.
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Affiliation(s)
- Wei-Feng Wang
- Central Laboratory, Shanghai Tenth People's Hospital, Tongji University, Shanghai, 200072, China.,Institute for Infectious Diseases and Vaccine Development, Tongji University School of Medicine, 1239 Siping Road, Shanghai, 200092, China
| | - Yi-Long Zhang
- Department of Tropical Diseases, Faculty of Naval Medicine, Second Military Medical University, Shanghai, 200433, China. .,Institute for Infectious Diseases and Vaccine Development, Tongji University School of Medicine, 1239 Siping Road, Shanghai, 200092, China.
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26
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Liu M, Lu B, Fan Y, He X, Shen S, Jiang C, Zhang Q. TRIBE Uncovers the Role of Dis3 in Shaping the Dynamic Transcriptome in Malaria Parasites. Front Cell Dev Biol 2019; 7:264. [PMID: 31737630 PMCID: PMC6838019 DOI: 10.3389/fcell.2019.00264] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Accepted: 10/18/2019] [Indexed: 02/06/2023] Open
Abstract
Identification of RNA targets of RNA-binding proteins (RBPs) is essential for complete understanding of their biological functions. However, it is still a challenge to identify the biologically relevant targets of RBPs through in vitro strategies of RIP-seq, HITS-CLIP, or GoldCLIP due to the potentially high background and complicated manipulation. In malaria parasites, RIP-seq and gene disruption are the few tools available currently for identification of RBP targets. Here, we have adopted the TRIBE (Targets of RNA binding proteins identified by editing) system to in vivo identify the RNA targets of PfDis3, a key exoribonuclease subunit of RNA exosome in Plasmodium falciparum. We generated a transgenic parasite line of PfDis3-ADARcd, which catalyzes an adenosine (A)-to-inosine (I) conversion at the potential interacting sites of PfDis3-targeting RNAs. Most of PfDis3 target genes contain one edit site. The majority of the edit sites detected by PfDis3-TRIBE locate in exons and spread across the entire coding regions. The nucleotides adjacent to the edit sites contain ∼75% of A + T. PfDis3-TRIBE target genes are biases toward higher RIP enrichment, suggesting that PfDis3-TRIBE preferentially detects stronger PfDis3 RIP targets. Collectively, PfDis3-TRIBE is a favorable tool to identify in vivo target genes of RBP with high efficiency and reproducibility. Additionally, the PfDis3-targeting genes are involved in stage-related biological processes during the blood-stage development. Thus PfDis3 appears to shape the dynamic transcriptional transcriptome of malaria parasites through post-transcriptional degradation of a variety of unwanted transcripts from both strands in the asexual blood stage.
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Affiliation(s)
- Meng Liu
- Institute of Translational Research, Tongji Hospital, Shanghai Key Laboratory of Signaling and Disease Research, The School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Binbin Lu
- Research Center for Translational Medicine, Key Laboratory of Arrhythmias of the Ministry of Education of China, East Hospital, Tongji University School of Medicine, Shanghai, China
| | - Yanting Fan
- Research Center for Translational Medicine, Key Laboratory of Arrhythmias of the Ministry of Education of China, East Hospital, Tongji University School of Medicine, Shanghai, China
| | - Xiaohui He
- Research Center for Translational Medicine, Key Laboratory of Arrhythmias of the Ministry of Education of China, East Hospital, Tongji University School of Medicine, Shanghai, China
| | - Shijun Shen
- Institute of Translational Research, Tongji Hospital, Shanghai Key Laboratory of Signaling and Disease Research, The School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Cizhong Jiang
- Institute of Translational Research, Tongji Hospital, Shanghai Key Laboratory of Signaling and Disease Research, The School of Life Sciences and Technology, Tongji University, Shanghai, China.,The Research Center of Stem Cells and Ageing, Tsingtao Advanced Research Institute, Tongji University, Shanghai, China
| | - Qingfeng Zhang
- Research Center for Translational Medicine, Key Laboratory of Arrhythmias of the Ministry of Education of China, East Hospital, Tongji University School of Medicine, Shanghai, China
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27
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Bennink S, Pradel G. The molecular machinery of translational control in malaria parasites. Mol Microbiol 2019; 112:1658-1673. [PMID: 31531994 DOI: 10.1111/mmi.14388] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/14/2019] [Indexed: 12/30/2022]
Abstract
Translational control regulates the levels of protein synthesized from its transcript and is key for the rapid adjustment of gene expression in response to environmental stimuli. The regulation of translation is of special importance for malaria parasites, which pass through a complex life cycle that includes various replication phases in the different organs of the human and mosquito hosts and a sexual reproduction phase in the mosquito midgut. In particular, the quiescent transmission stages rely on translational control to rapidly adapt to the new environment, once they switch over from the human to the mosquito and vice versa. Three control mechanisms are currently proposed in Plasmodium, (1) global regulation that acts on the translation initiation complex; (2) mRNA-specific regulation, involving cis control elements, mRNA-binding proteins and translational repressors; and (3) induced mRNA decay by the Ccr4-Not and the RNA exosome complex. The main molecules controlling translation are highly conserved in malaria parasites and an increasing number of studies shed light on the interwoven pathways leading to the up or downregulation of protein synthesis in the diverse plasmodial stages. We here highlight recent findings on translational control during life cycle progression of Plasmodium and discuss the molecules involved in regulating protein synthesis.
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Affiliation(s)
- Sandra Bennink
- Division of Cellular and Applied Infection Biology, Institute of Zoology, RWTH Aachen University, Worringerweg 1, 52074, Aachen, Germany
| | - Gabriele Pradel
- Division of Cellular and Applied Infection Biology, Institute of Zoology, RWTH Aachen University, Worringerweg 1, 52074, Aachen, Germany
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28
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Briggs E, Crouch K, Lemgruber L, Lapsley C, McCulloch R. Ribonuclease H1-targeted R-loops in surface antigen gene expression sites can direct trypanosome immune evasion. PLoS Genet 2018; 14:e1007729. [PMID: 30543624 PMCID: PMC6292569 DOI: 10.1371/journal.pgen.1007729] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Accepted: 10/01/2018] [Indexed: 11/19/2022] Open
Abstract
Switching of the Variant Surface Glycoprotein (VSG) in Trypanosoma brucei provides a crucial host immune evasion strategy that is catalysed both by transcription and recombination reactions, each operating within specialised telomeric VSG expression sites (ES). VSG switching is likely triggered by events focused on the single actively transcribed ES, from a repertoire of around 15, but the nature of such events is unclear. Here we show that RNA-DNA hybrids, called R-loops, form preferentially within sequences termed the 70 bp repeats in the actively transcribed ES, but spread throughout the active and inactive ES, in the absence of RNase H1, which degrades R-loops. Loss of RNase H1 also leads to increased levels of VSG coat switching and replication-associated genome damage, some of which accumulates within the active ES. This work indicates VSG ES architecture elicits R-loop formation, and that these RNA-DNA hybrids connect T. brucei immune evasion by transcription and recombination.
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Affiliation(s)
- Emma Briggs
- The Wellcome Centre for Molecular Parasitology, University of Glasgow, College of Medical, Veterinary and Life Sciences, Institute of Infection, Immunity and Inflammation, Glasgow, United Kingdom
| | - Kathryn Crouch
- The Wellcome Centre for Molecular Parasitology, University of Glasgow, College of Medical, Veterinary and Life Sciences, Institute of Infection, Immunity and Inflammation, Glasgow, United Kingdom
| | - Leandro Lemgruber
- The Wellcome Centre for Molecular Parasitology, University of Glasgow, College of Medical, Veterinary and Life Sciences, Institute of Infection, Immunity and Inflammation, Glasgow, United Kingdom
| | - Craig Lapsley
- The Wellcome Centre for Molecular Parasitology, University of Glasgow, College of Medical, Veterinary and Life Sciences, Institute of Infection, Immunity and Inflammation, Glasgow, United Kingdom
| | - Richard McCulloch
- The Wellcome Centre for Molecular Parasitology, University of Glasgow, College of Medical, Veterinary and Life Sciences, Institute of Infection, Immunity and Inflammation, Glasgow, United Kingdom
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29
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Droll D, Wei G, Guo G, Fan Y, Baumgarten S, Zhou Y, Xiao Y, Scherf A, Zhang Q. Disruption of the RNA exosome reveals the hidden face of the malaria parasite transcriptome. RNA Biol 2018; 15:1206-1214. [PMID: 30235972 PMCID: PMC7000224 DOI: 10.1080/15476286.2018.1517014] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
Abstract
Antisense transcription emerges as a key regulator of important biological processes in the human malaria parasite Plasmodium falciparum. RNA-processing factors, however, remain poorly characterized in this pathogen. Here, we purified the multiprotein RNA exosome complex of malaria parasites by affinity chromatography, using HA-tagged PfRrp4 and PfDis3 as the ligands. Seven distinct core exosome subunits (PfRrp41, PfMtr3, PfRrp42, PfRrp45, PfRrp4, PfRrp40, PfCsl4) and two exoribonuclease proteins PfRrp6 and PfDis3 are identified by mass spectrometry. Western blot analysis detects Dis3 and Rrp4 predominantly in the cytoplasmic fraction during asexual blood stage development. An inducible gene knock out of the PfDis3 subunit reveals the upregulation of structural and coding RNA, but the vast majority belongs to antisense RNA. Furthermore, we detect numerous types of cryptic unstable transcripts (CUTs) linked to virulence gene families including antisense RNA in the rif gene family. Our work highlights the limitations of steady-state RNA analysis to predict transcriptional activity and link the RNA surveillance machinery directly with post-transcriptional control and gene expression in malaria parasites.
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Affiliation(s)
- Dorothea Droll
- a Unité Biologie des Interactions Hôte-Parasite, Département de Parasites et Insectes Vecteurs , Institut Pasteur , Paris , France.,b CNRS, ERL 9195 , Paris , France.,c INSERM, Unit U1201 , Paris , France
| | - Guiying Wei
- d Research Center for Translational Medicine, Key Laboratory of Arrhythmias of the Ministry of Education of China, East Hospital , Tongji University School of Medicine , Shanghai , China
| | - Gangqiang Guo
- d Research Center for Translational Medicine, Key Laboratory of Arrhythmias of the Ministry of Education of China, East Hospital , Tongji University School of Medicine , Shanghai , China
| | - Yanting Fan
- d Research Center for Translational Medicine, Key Laboratory of Arrhythmias of the Ministry of Education of China, East Hospital , Tongji University School of Medicine , Shanghai , China
| | - Sebastian Baumgarten
- a Unité Biologie des Interactions Hôte-Parasite, Département de Parasites et Insectes Vecteurs , Institut Pasteur , Paris , France.,b CNRS, ERL 9195 , Paris , France.,c INSERM, Unit U1201 , Paris , France
| | - Yiqing Zhou
- e CAS Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology , Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences , Shanghai , China
| | - Youli Xiao
- e CAS Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology , Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences , Shanghai , China
| | - Artur Scherf
- a Unité Biologie des Interactions Hôte-Parasite, Département de Parasites et Insectes Vecteurs , Institut Pasteur , Paris , France.,b CNRS, ERL 9195 , Paris , France.,c INSERM, Unit U1201 , Paris , France
| | - Qingfeng Zhang
- d Research Center for Translational Medicine, Key Laboratory of Arrhythmias of the Ministry of Education of China, East Hospital , Tongji University School of Medicine , Shanghai , China
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Dos Santos RF, Quendera AP, Boavida S, Seixas AF, Arraiano CM, Andrade JM. Major 3'-5' Exoribonucleases in the Metabolism of Coding and Non-coding RNA. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2018; 159:101-155. [PMID: 30340785 DOI: 10.1016/bs.pmbts.2018.07.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
3'-5' exoribonucleases are key enzymes in the degradation of superfluous or aberrant RNAs and in the maturation of precursor RNAs into their functional forms. The major bacterial 3'-5' exoribonucleases responsible for both these activities are PNPase, RNase II and RNase R. These enzymes are of ancient nature with widespread distribution. In eukaryotes, PNPase and RNase II/RNase R enzymes can be found in the cytosol and in mitochondria and chloroplasts; RNase II/RNase R-like enzymes are also found in the nucleus. Humans express one PNPase (PNPT1) and three RNase II/RNase R family members (Dis3, Dis3L and Dis3L2). These enzymes take part in a multitude of RNA surveillance mechanisms that are critical for translation accuracy. Although active against a wide range of both coding and non-coding RNAs, the different 3'-5' exoribonucleases exhibit distinct substrate affinities. The latest studies on these RNA degradative enzymes have contributed to the identification of additional homologue proteins, the uncovering of novel RNA degradation pathways, and to a better comprehension of several disease-related processes and response to stress, amongst many other exciting findings. Here, we provide a comprehensive and up-to-date overview on the function, structure, regulation and substrate preference of the key 3'-5' exoribonucleases involved in RNA metabolism.
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Affiliation(s)
- Ricardo F Dos Santos
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Ana P Quendera
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Sofia Boavida
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - André F Seixas
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Cecília M Arraiano
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - José M Andrade
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal.
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Zhang M, Wang C, Otto TD, Oberstaller J, Liao X, Adapa SR, Udenze K, Bronner IF, Casandra D, Mayho M, Brown J, Li S, Swanson J, Rayner JC, Jiang RHY, Adams JH. Uncovering the essential genes of the human malaria parasite Plasmodium falciparum by saturation mutagenesis. Science 2018; 360:360/6388/eaap7847. [PMID: 29724925 DOI: 10.1126/science.aap7847] [Citation(s) in RCA: 537] [Impact Index Per Article: 89.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Accepted: 03/02/2018] [Indexed: 12/22/2022]
Abstract
Severe malaria is caused by the apicomplexan parasite Plasmodium falciparum. Despite decades of research, the distinct biology of these parasites has made it challenging to establish high-throughput genetic approaches to identify and prioritize therapeutic targets. Using transposon mutagenesis of P. falciparum in an approach that exploited its AT-rich genome, we generated more than 38,000 mutants, saturating the genome and defining mutability and fitness costs for over 87% of genes. Of 5399 genes, our study defined 2680 genes as essential for optimal growth of asexual blood stages in vitro. These essential genes are associated with drug resistance, represent leading vaccine candidates, and include approximately 1000 Plasmodium-conserved genes of unknown function. We validated this approach by testing proteasome pathways for individual mutants associated with artemisinin sensitivity.
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Affiliation(s)
- Min Zhang
- Center for Global Health and Infectious Diseases, Department of Global Health, University of South Florida, 3720 Spectrum Boulevard, Suite 404, Tampa, FL 33612, USA
| | - Chengqi Wang
- Center for Global Health and Infectious Diseases, Department of Global Health, University of South Florida, 3720 Spectrum Boulevard, Suite 404, Tampa, FL 33612, USA
| | - Thomas D Otto
- Malaria Programme, Wellcome Trust Sanger Institute, Genome Campus, Hinxton Cambridgeshire CB10 1SA, UK
| | - Jenna Oberstaller
- Center for Global Health and Infectious Diseases, Department of Global Health, University of South Florida, 3720 Spectrum Boulevard, Suite 404, Tampa, FL 33612, USA
| | - Xiangyun Liao
- Center for Global Health and Infectious Diseases, Department of Global Health, University of South Florida, 3720 Spectrum Boulevard, Suite 404, Tampa, FL 33612, USA
| | - Swamy R Adapa
- Center for Global Health and Infectious Diseases, Department of Global Health, University of South Florida, 3720 Spectrum Boulevard, Suite 404, Tampa, FL 33612, USA
| | - Kenneth Udenze
- Center for Global Health and Infectious Diseases, Department of Global Health, University of South Florida, 3720 Spectrum Boulevard, Suite 404, Tampa, FL 33612, USA
| | - Iraad F Bronner
- Malaria Programme, Wellcome Trust Sanger Institute, Genome Campus, Hinxton Cambridgeshire CB10 1SA, UK
| | - Deborah Casandra
- Center for Global Health and Infectious Diseases, Department of Global Health, University of South Florida, 3720 Spectrum Boulevard, Suite 404, Tampa, FL 33612, USA
| | - Matthew Mayho
- Malaria Programme, Wellcome Trust Sanger Institute, Genome Campus, Hinxton Cambridgeshire CB10 1SA, UK
| | - Jacqueline Brown
- Malaria Programme, Wellcome Trust Sanger Institute, Genome Campus, Hinxton Cambridgeshire CB10 1SA, UK
| | - Suzanne Li
- Center for Global Health and Infectious Diseases, Department of Global Health, University of South Florida, 3720 Spectrum Boulevard, Suite 404, Tampa, FL 33612, USA
| | - Justin Swanson
- Center for Global Health and Infectious Diseases, Department of Global Health, University of South Florida, 3720 Spectrum Boulevard, Suite 404, Tampa, FL 33612, USA
| | - Julian C Rayner
- Malaria Programme, Wellcome Trust Sanger Institute, Genome Campus, Hinxton Cambridgeshire CB10 1SA, UK.
| | - Rays H Y Jiang
- Center for Global Health and Infectious Diseases, Department of Global Health, University of South Florida, 3720 Spectrum Boulevard, Suite 404, Tampa, FL 33612, USA.
| | - John H Adams
- Center for Global Health and Infectious Diseases, Department of Global Health, University of South Florida, 3720 Spectrum Boulevard, Suite 404, Tampa, FL 33612, USA.
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32
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Abstract
Eukaryotic pathogens must survive in different hosts, respond to changing environments, and exploit specialized niches to propagate. Plasmodium parasites cause human malaria during bloodstream infections, where they must persist long enough to be transmitted. Parasites have evolved diverse strategies of variant gene expression that control critical biological processes of blood-stage infections, including antigenic variation, erythrocyte invasion, innate immune evasion, and nutrient acquisition, as well as life-cycle transitions. Epigenetic mechanisms within the parasite are being elucidated, with discovery of epigenomic marks associated with gene silencing and activation, and the identification of epigenetic regulators and chromatin proteins that are required for the switching and maintenance of gene expression. Here, we review the key epigenetic processes that facilitate transition through the parasite life cycle and epigenetic regulatory mechanisms utilized by Plasmodium parasites to survive changing environments and consider epigenetic switching in the context of the outcome of human infections.
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Affiliation(s)
- Manoj T Duraisingh
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts 02115, USA; ,
| | - Kristen M Skillman
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts 02115, USA; ,
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33
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Jiang N, Yu S, Yang N, Feng Y, Sang X, Wang Y, Wahlgren M, Chen Q. Characterization of the Catalytic Subunits of the RNA Exosome-like Complex in Plasmodium falciparum. J Eukaryot Microbiol 2018; 65:843-853. [PMID: 29664138 PMCID: PMC6282785 DOI: 10.1111/jeu.12625] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Revised: 04/02/2018] [Accepted: 04/03/2018] [Indexed: 12/21/2022]
Abstract
The eukaryotic ribonucleic acid (RNA) exosome is a versatile multiribonuclease complex that mediates the processing, surveillance, and degradation of virtually all classes of RNA in both the nucleus and cytoplasm. The complex, composed of 10 to 11 subunits, has been widely described in many organisms. Bioinformatic analyses revealed that there may be also an exosome‐like complex in Plasmodium falciparum, a parasite of great importance in public health, with eight predicted subunits having high sequence similarity to their counterparts in yeast and human. In this work, the putative RNA catalytic components, designated as PfRrp4, PfRrp41, PfDis3, and PfRrp6, were identified and systematically analyzed. Quantitative polymerase chain reaction (QPCR) analyses suggested that all of them were transcribed steadily throughout the asexual stage. The expression of these proteins was determined by Western blot, and their localization narrowed to the cytoplasm of the parasite by indirect immunofluorescence. The recombinant proteins of PfRrp41, PfDis3, and PfRrp6 exhibited catalytic activity for single‐stranded RNA (ssRNA), whereas PfRrp4 showed no processing activity of both ssRNA and dsRNA. The identification of these putative components of the RNA exosome complex opens up new perspectives for a deep understanding of RNA metabolism in the malarial parasite P. falciparum.
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Affiliation(s)
- Ning Jiang
- Key Laboratory of Zoonosis, Shenyang Agricultural University, 120 Dongling Road, Shenyang, China
| | - Shengchao Yu
- Key Laboratory of Zoonosis, Jilin University, 53333 Xi An Da Lu, Changchun, 130062, China
| | - Na Yang
- Key Laboratory of Zoonosis, Shenyang Agricultural University, 120 Dongling Road, Shenyang, China
| | - Ying Feng
- Key Laboratory of Zoonosis, Shenyang Agricultural University, 120 Dongling Road, Shenyang, China
| | - Xiaoyu Sang
- Key Laboratory of Zoonosis, Shenyang Agricultural University, 120 Dongling Road, Shenyang, China
| | - Yao Wang
- Key Laboratory of Zoonosis, Shenyang Agricultural University, 120 Dongling Road, Shenyang, China
| | - Mats Wahlgren
- Department of Microbiology, Tumour and Cellular Biology, Karolinska Institutet, Nobels väg 16, Stockholm, Sweden
| | - Qijun Chen
- Key Laboratory of Zoonosis, Shenyang Agricultural University, 120 Dongling Road, Shenyang, China.,Department of Microbiology, Tumour and Cellular Biology, Karolinska Institutet, Nobels väg 16, Stockholm, Sweden
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Abstract
Protozoan parasites colonize numerous metazoan hosts and insect vectors through their life cycles, with the need to respond quickly and reversibly while encountering diverse and often hostile ecological niches. To succeed, parasites must also persist within individuals until transmission between hosts is achieved. Several parasitic protozoa cause a huge burden of disease in humans and livestock, and here we focus on the parasites that cause malaria and African trypanosomiasis. Efforts to understand how these pathogens adapt to survive in varied host environments, cause disease, and transmit between hosts have revealed a wealth of epigenetic phenomena. Epigenetic switching mechanisms appear to be ideally suited for the regulation of clonal antigenic variation underlying successful parasitism. We review the molecular players and complex mechanistic layers that mediate the epigenetic regulation of virulence gene expression. Understanding epigenetic processes will aid the development of antiparasitic therapeutics.
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Affiliation(s)
- Manoj T Duraisingh
- Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, 651 Huntington Avenue, Boston, MA 02115, USA.
| | - David Horn
- Division of Biological Chemistry & Drug Discovery, School of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, UK.
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35
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Red blood cells release microparticles containing human argonaute 2 and miRNAs to target genes of Plasmodium falciparum. Emerg Microbes Infect 2017; 6:e75. [PMID: 28831191 PMCID: PMC5583671 DOI: 10.1038/emi.2017.63] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Revised: 05/19/2017] [Accepted: 06/11/2017] [Indexed: 12/11/2022]
Abstract
Red blood cells (RBCs) are known to function as a refuge for providing food resources and as a shelter against the host’s immune system after malaria parasite (Plasmodium) infection. Recent studies have reported significant production of extracellular vesicles (microparticles, MPs) in the circulation of malaria patients. However, it is unclear how these extracellular vesicles are generated and what their biological functions are. In this study, we isolated the MPs from a culture medium of normal RBCs and malaria parasite-infected RBCs (iRBCs), compared their quantity and origins, and profiled their miRNAs by deep sequencing. We found a much larger number of MPs released in the culture of iRBCs than in the culture of normal RBCs. Further investigation indicated that, in these MPs, human argonaute 2 (hAgo2) was found to bind to hundreds of miRNAs. These hAgo2-miRNA complexes were transferred into the parasites, and the expression of an essential malaria antigen, PfEMP1, was downregulated by miR-451/140 through its binding to the A and B subgroups of var genes, a family of genes encoding PfEMP1. Our data suggest for the first time that, through the release of MPs, mature RBCs present an innate resistance to malaria infection. These studies also shed new light on the reason why RBCs’ genetic mutation occurs mainly in populations living in intensive malaria endemic areas and on the possibility of using miRNAs as novel medicines for malaria patients.
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36
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Knockdown of the Plasmodium falciparum SURFIN4.1 antigen leads to an increase of its cognate transcript. PLoS One 2017; 12:e0183129. [PMID: 28800640 PMCID: PMC5553854 DOI: 10.1371/journal.pone.0183129] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Accepted: 07/31/2017] [Indexed: 11/24/2022] Open
Abstract
The genome of the malaria parasite Plasmodium falciparum contains the surf gene family which encodes large transmembrane proteins of unknown function. While some surf alleles appear to be expressed in sexual stages, others occur in asexual blood stage forms and may be associated to virulence-associated processes and undergo transcriptional switching. We accessed the transcription of surf genes along multiple invasions by real time PCR. Based on the observation of persistent expression of gene surf4.1, we created a parasite line which expresses a conditionally destabilized SURFIN4.1 protein. Upon destabilization of the protein, no interference of parasite growth or morphological changes were detected. However, we observed a strong increase in the transcript quantities of surf4.1 and sometimes of other surf genes in knocked-down parasites. While this effect was reversible when SURFIN4.1 was stabilized again after a few days of destabilization, longer destabilization periods resulted in a transcriptional switch away from surf4.1. When we tested if a longer transcript half-life was responsible for increased transcript detection in SURFIN4.1 knocked-down parasites, no alteration was found compared to control parasite lines. This suggests a specific feedback of the expressed SURFIN protein to its transcript pointing to a novel type of regulation, inedited in Plasmodium.
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37
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Abstract
Malaria is a significant threat throughout the developing world. Among the most fascinating aspects of the protozoan parasites responsible for this disease are the methods they employ to avoid the immune system and perpetuate chronic infections. Key among these is antigenic variation: By systematically altering antigens that are displayed to the host's immune system, the parasite renders the adaptive immune response ineffective. For Plasmodium falciparum, the species responsible for the most severe form of human malaria, this process involves a complicated molecular mechanism that results in continuously changing patterns of variant-antigen-encoding gene expression. Although many features of this process remain obscure, significant progress has been made in recent years to decipher various molecular aspects of the regulatory cascade that causes chronic infection.
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Affiliation(s)
- Kirk W Deitsch
- Department of Microbiology and Immunology, Weill Medical College of Cornell University, New York, NY 10065;
| | - Ron Dzikowski
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada and Kuvin Center for the Study of Infectious and Tropical Diseases, Hebrew University Hadassah Medical School, Jerusalem 91120, Israel;
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38
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CRISPR/Cas9 Genome Editing Reveals That the Intron Is Not Essential for var2csa Gene Activation or Silencing in Plasmodium falciparum. mBio 2017; 8:mBio.00729-17. [PMID: 28698275 PMCID: PMC5513710 DOI: 10.1128/mbio.00729-17] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Plasmodium falciparum relies on monoallelic expression of 1 of 60 var virulence genes for antigenic variation and host immune evasion. Each var gene contains a conserved intron which has been implicated in previous studies in both activation and repression of transcription via several epigenetic mechanisms, including interaction with the var promoter, production of long noncoding RNAs (lncRNAs), and localization to repressive perinuclear sites. However, functional studies have relied primarily on artificial expression constructs. Using the recently developed P. falciparum clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 system, we directly deleted the var2csa P. falciparum 3D7_1200600 (Pf3D7_1200600) endogenous intron, resulting in an intronless var gene in a natural, marker-free chromosomal context. Deletion of the var2csa intron resulted in an upregulation of transcription of the var2csa gene in ring-stage parasites and subsequent expression of the PfEMP1 protein in late-stage parasites. Intron deletion did not affect the normal temporal regulation and subsequent transcriptional silencing of the var gene in trophozoites but did result in increased rates of var gene switching in some mutant clones. Transcriptional repression of the intronless var2csa gene could be achieved via long-term culture or panning with the CD36 receptor, after which reactivation was possible with chondroitin sulfate A (CSA) panning. These data suggest that the var2csa intron is not required for silencing or activation in ring-stage parasites but point to a subtle role in regulation of switching within the var gene family.IMPORTANCEPlasmodium falciparum is the most virulent species of malaria parasite, causing high rates of morbidity and mortality in those infected. Chronic infection depends on an immune evasion mechanism termed antigenic variation, which in turn relies on monoallelic expression of 1 of ~60 var genes. Understanding antigenic variation and the transcriptional regulation of monoallelic expression is important for developing drugs and/or vaccines. The var gene family encodes the antigenic surface proteins that decorate infected erythrocytes. Until recently, studying the underlying genetic elements that regulate monoallelic expression in P. falciparum was difficult, and most studies relied on artificial systems such as episomal reporter genes. Our study was the first to use CRISPR/Cas9 genome editing for the functional study of an important, conserved genetic element of var genes-the intron-in an endogenous, episome-free manner. Our findings shed light on the role of the var gene intron in transcriptional regulation of monoallelic expression.
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39
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Abstract
Organisms with identical genome sequences can show substantial differences in their phenotypes owing to epigenetic changes that result in different use of their genes. Epigenetic regulation of gene expression plays a key role in the control of several fundamental processes in the biology of malaria parasites, including antigenic variation and sexual differentiation. Some of the histone modifications and chromatin-modifying enzymes that control the epigenetic states of malaria genes have been characterized, and their functions are beginning to be unraveled. The fundamental principles of epigenetic regulation of gene expression appear to be conserved between malaria parasites and model eukaryotes, but important peculiarities exist. Here, we review the current knowledge of malaria epigenetics and discuss how it can be exploited for the development of new molecular markers and new types of drugs that may contribute to malaria eradication efforts.
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Affiliation(s)
- Alfred Cortés
- ISGlobal, Barcelona Centre for International Health Research (CRESIB), Hospital Clínic - Universitat de Barcelona, Barcelona, Catalonia 08036, Spain.,ICREA, Barcelona, Catalonia 08010, Spain
| | - Kirk W Deitsch
- Department of Microbiology and Immunology, Weill Medical College of Cornell University, New York, New York 10065
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40
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Tools for attenuation of gene expression in malaria parasites. Int J Parasitol 2017; 47:385-398. [PMID: 28153780 DOI: 10.1016/j.ijpara.2016.11.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Revised: 09/15/2016] [Accepted: 11/28/2016] [Indexed: 12/30/2022]
Abstract
An understanding of the biology of Plasmodium parasites, which are the causative agents of the disease malaria, requires study of gene function. Various reverse genetic tools have been described for determining gene function. These tools can be broadly grouped as trans- and cis-acting. Trans-acting tools control gene functions through synthetic nucleic acid probe molecules matching the sequence of the gene of interest. Once delivered to the parasite, the probe engages with the mRNA of the target gene and attenuates its function. Cis-acting tools control gene function through elements introduced into the gene of interest by DNA transfection. The expression of the modified gene can be controlled using external agents, typically small molecule ligands. In this review, we discuss the strengths and weaknesses of these tools to guide researchers in selecting the appropriate tool for studies of gene function, and for guiding future refinements of these tools.
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41
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Gómez-Díaz E, Yerbanga RS, Lefèvre T, Cohuet A, Rowley MJ, Ouedraogo JB, Corces VG. Epigenetic regulation of Plasmodium falciparum clonally variant gene expression during development in Anopheles gambiae. Sci Rep 2017; 7:40655. [PMID: 28091569 PMCID: PMC5238449 DOI: 10.1038/srep40655] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Accepted: 12/09/2016] [Indexed: 12/17/2022] Open
Abstract
P. falciparum phenotypic plasticity is linked to the variant expression of clonal multigene families such as the var genes. We have examined changes in transcription and histone modifications that occur during sporogonic development of P. falciparum in the mosquito host. All var genes are silenced or transcribed at low levels in blood stages (gametocyte/ring) of the parasite in the human host. After infection of mosquitoes, a single var gene is selected for expression in the oocyst, and transcription of this gene increases dramatically in the sporozoite. The same PF3D7_1255200 var gene was activated in 4 different experimental infections. Transcription of this var gene during parasite development in the mosquito correlates with the presence of low levels of H3K9me3 at the binding site for the PF3D7_1466400 AP2 transcription factor. This chromatin state in the sporozoite also correlates with the expression of an antisense long non-coding RNA (lncRNA) that has previously been shown to promote var gene transcription during the intraerythrocytic cycle in vitro. Expression of both the sense protein-coding transcript and the antisense lncRNA increase dramatically in sporozoites. The findings suggest a complex process for the activation of a single particular var gene that involves AP2 transcription factors and lncRNAs.
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42
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Abstract
Malaria continues to impose a significant disease burden on low- and middle-income countries in the tropics. However, revolutionary progress over the last 3 years in nucleic acid sequencing, reverse genetics, and post-genome analyses has generated step changes in our understanding of malaria parasite (Plasmodium spp.) biology and its interactions with its host and vector. Driven by the availability of vast amounts of genome sequence data from Plasmodium species strains, relevant human populations of different ethnicities, and mosquito vectors, researchers can consider any biological component of the malarial process in isolation or in the interactive setting that is infection. In particular, considerable progress has been made in the area of population genomics, with Plasmodium falciparum serving as a highly relevant model. Such studies have demonstrated that genome evolution under strong selective pressure can be detected. These data, combined with reverse genetics, have enabled the identification of the region of the P. falciparum genome that is under selective pressure and the confirmation of the functionality of the mutations in the kelch13 gene that accompany resistance to the major frontline antimalarial, artemisinin. Furthermore, the central role of epigenetic regulation of gene expression and antigenic variation and developmental fate in P. falciparum is becoming ever clearer. This review summarizes recent exciting discoveries that genome technologies have enabled in malaria research and highlights some of their applications to healthcare. The knowledge gained will help to develop surveillance approaches for the emergence or spread of drug resistance and to identify new targets for the development of antimalarial drugs and perhaps vaccines.
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Affiliation(s)
- Sebastian Kirchner
- Wellcome Trust Centre for Molecular Parasitology, Institute of Infection, Immunity and Inflammation, College of Medical Veterinary & Life Sciences, University of Glasgow, Glasgow, G12 8TA, UK
| | - B Joanne Power
- Wellcome Trust Centre for Molecular Parasitology, Institute of Infection, Immunity and Inflammation, College of Medical Veterinary & Life Sciences, University of Glasgow, Glasgow, G12 8TA, UK
| | - Andrew P Waters
- Wellcome Trust Centre for Molecular Parasitology, Institute of Infection, Immunity and Inflammation, College of Medical Veterinary & Life Sciences, University of Glasgow, Glasgow, G12 8TA, UK.
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43
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Wang C, Adapa SR, Gibbons J, Sutton S, Jiang RHY. Punctuated chromatin states regulate Plasmodium falciparum antigenic variation at the intron and 2 kb upstream regions. BMC Genomics 2016; 17:652. [PMID: 27538502 PMCID: PMC4990864 DOI: 10.1186/s12864-016-3005-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Accepted: 08/10/2016] [Indexed: 11/27/2022] Open
Abstract
Background Understanding the regulation mechanism of var gene expression is crucial for explaining antigenic variation in Plasmodium falciparum. Recent work observed that while all var genes produce transcripts, only a few var genes exhibit high expression levels. However, the global regulation of var expression and the relationship between epigenetic and genetic control remains to be established. Result We have systematically reanalyzed the existing genomic data including chromatin configurations and gene expressions; and for the first time used robust statistical methods to show that the intron and 2 kb upstream regions of each endogenous var gene always maintain high chromatin accessibility, with high potential to bind transcription factors (TFs). The levels of transcripts for different var gene family members are associated with this chromatin accessibility. Any given var gene thus shows punctuated chromatin states throughout the asexual life cycle. This is demonstrated by three independent transcript datasets. Chromatin accessibility in the var intron and 2 kb upstream regions are also positively correlated with their GC content, suggesting the level of var genes silencing might be encoded in their intron sequences. Interestingly, both var intron and 2 kb upstream regions exhibit higher chromatin accessibility when the genes have relatively lower transcription levels, suggesting a punctuated repressive function for these regulatory elements. Conclusion By integrating and analyzing epigenomic, genomic and transcriptomic data, our work reveals a novel distal element in var control. We found dynamic modulations of specific epigenetic marks around the var intron and distal upstream regions are involved in the general var gene expression patterns in malarial antigenic variation. Electronic supplementary material The online version of this article (doi:10.1186/s12864-016-3005-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Chengqi Wang
- Department of Global Health (GH) & Center for Drug Discovery and Innovation (CDDI), College of Public Health, University of South Florida, Tampa, FL, 33612, USA
| | - Swamy R Adapa
- Department of Global Health (GH) & Center for Drug Discovery and Innovation (CDDI), College of Public Health, University of South Florida, Tampa, FL, 33612, USA
| | - Justin Gibbons
- Department of Global Health (GH) & Center for Drug Discovery and Innovation (CDDI), College of Public Health, University of South Florida, Tampa, FL, 33612, USA.,Department of Molecular Medicine, University of South Florida, Tampa, FL, 33612, USA
| | - Stephen Sutton
- Department of Global Health (GH) & Center for Drug Discovery and Innovation (CDDI), College of Public Health, University of South Florida, Tampa, FL, 33612, USA
| | - Rays H Y Jiang
- Department of Global Health (GH) & Center for Drug Discovery and Innovation (CDDI), College of Public Health, University of South Florida, Tampa, FL, 33612, USA.
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44
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Guizetti J, Barcons-Simon A, Scherf A. Trans-acting GC-rich non-coding RNA at var expression site modulates gene counting in malaria parasite. Nucleic Acids Res 2016; 44:9710-9718. [PMID: 27466391 PMCID: PMC5175341 DOI: 10.1093/nar/gkw664] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Revised: 06/20/2016] [Accepted: 07/13/2016] [Indexed: 11/14/2022] Open
Abstract
Monoallelic expression of the var multigene family enables immune evasion of the malaria parasite Plasmodium falciparum in its human host. At a given time only a single member of the 60-member var gene family is expressed at a discrete perinuclear region called the 'var expression site'. However, the mechanism of var gene counting remains ill-defined. We hypothesize that activation factors associating specifically with the expression site play a key role in this process. Here, we investigate the role of a GC-rich non-coding RNA (ncRNA) gene family composed of 15 highly homologous members. GC-rich genes are positioned adjacent to var genes in chromosome-central gene clusters but are absent near subtelomeric var genes. Fluorescence in situ hybridization demonstrates that GC-rich ncRNA localizes to the perinuclear expression site of central and subtelomeric var genes in trans. Importantly, overexpression of distinct GC-rich ncRNA members disrupts the gene counting process at the single cell level and results in activation of a specific subset of var genes in distinct clones. We identify the first trans-acting factor targeted to the elusive perinuclear var expression site and open up new avenues to investigate ncRNA function in antigenic variation of malaria and other protozoan pathogens.
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Affiliation(s)
- Julien Guizetti
- Unité de Biologie des Interactions Hôte-Parasite, Institut Pasteur, Paris, 75724, France .,INSERM U1201, F-75724 Paris, France.,CNRS ERL9195, F-75724 Paris, France
| | - Anna Barcons-Simon
- Unité de Biologie des Interactions Hôte-Parasite, Institut Pasteur, Paris, 75724, France.,INSERM U1201, F-75724 Paris, France.,CNRS ERL9195, F-75724 Paris, France
| | - Artur Scherf
- Unité de Biologie des Interactions Hôte-Parasite, Institut Pasteur, Paris, 75724, France .,INSERM U1201, F-75724 Paris, France.,CNRS ERL9195, F-75724 Paris, France
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The nuclear envelope and gene organization in parasitic protozoa: Specializations associated with disease. Mol Biochem Parasitol 2016; 209:104-113. [PMID: 27475118 DOI: 10.1016/j.molbiopara.2016.07.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Revised: 07/12/2016] [Accepted: 07/26/2016] [Indexed: 12/11/2022]
Abstract
The parasitic protozoa Trypanosoma brucei and Plasmodium falciparum are lethal human parasites that have developed elegant strategies of immune evasion by antigenic variation. Despite the vast evolutionary distance between the two taxa, both parasites employ strict monoallelic expression of their membrane proteins, variant surface glycoproteins in Trypanosomes and the var, rif and stevor genes in Plasmodium, in order to evade their host's immune system. Additionally, both telomeric location and epigenetic controls are prominent features of these membrane proteins. As such, telomeres, chromatin structure and nuclear organization all contribute to control of gene expression and immune evasion. Here, we discuss the importance of epigenetics and sub-nuclear context for the survival of these disease-causing parasites.
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Dimonte S, Bruske EI, Hass J, Supan C, Salazar CL, Held J, Tschan S, Esen M, Flötenmeyer M, Koch I, Berger J, Bachmann A, Sim BKL, Hoffman SL, Kremsner PG, Mordmüller B, Frank M. Sporozoite Route of Infection Influences In Vitro var Gene Transcription of Plasmodium falciparum Parasites From Controlled Human Infections. J Infect Dis 2016; 214:884-94. [PMID: 27279526 DOI: 10.1093/infdis/jiw225] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Accepted: 05/19/2016] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Antigenic variation in Plasmodium falciparum is mediated by the multicopy var gene family. Each parasite possesses about 60 var genes, and switching between active var loci results in antigenic variation. In the current study, the effect of mosquito and host passage on in vitro var gene transcription was investigated. METHODS Thirty malaria-naive individuals were inoculated by intradermal or intravenous injection with cryopreserved, isogenic NF54 P. falciparum sporozoites (PfSPZ) generated from 1 premosquito culture. Microscopic parasitemia developed in 22 individuals, and 21 in vitro cultures were established. The var gene transcript levels were determined in early and late postpatient cultures and in the premosquito culture. RESULTS At the early time point, all cultures preferentially transcribed 8 subtelomeric var genes. Intradermal infections had higher var gene transcript levels than intravenous infections and a significantly longer intrahost replication time (P = .03). At the late time point, 9 subtelomeric and 8 central var genes were transcribed at the same levels in almost all cultures. Premosquito and late postpatient cultures transcribed the same subtelomeric and central var genes, except for var2csa CONCLUSIONS The duration of intrahost replication influences in vitro var gene transcript patterns. Differences between premosquito and postpatient cultures decrease with prolonged in vitro growth.
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Affiliation(s)
- Sandra Dimonte
- Institute of Tropical Medicine University of Tübingen and German Center for Infection Research, Partner Site Tübingen
| | - Ellen I Bruske
- Institute of Tropical Medicine University of Tübingen and German Center for Infection Research, Partner Site Tübingen
| | - Johanna Hass
- Institute of Tropical Medicine University of Tübingen and German Center for Infection Research, Partner Site Tübingen
| | - Christian Supan
- Institute of Tropical Medicine University of Tübingen and German Center for Infection Research, Partner Site Tübingen
| | - Carmen L Salazar
- Institute of Tropical Medicine University of Tübingen and German Center for Infection Research, Partner Site Tübingen
| | - Jana Held
- Institute of Tropical Medicine University of Tübingen and German Center for Infection Research, Partner Site Tübingen
| | - Serena Tschan
- Institute of Tropical Medicine University of Tübingen and German Center for Infection Research, Partner Site Tübingen
| | - Meral Esen
- Institute of Tropical Medicine University of Tübingen and German Center for Infection Research, Partner Site Tübingen
| | | | - Iris Koch
- Max Planck Institute for Developmental Biology, Tübingen
| | - Jürgen Berger
- Max Planck Institute for Developmental Biology, Tübingen
| | - Anna Bachmann
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | | | | | - Peter G Kremsner
- Institute of Tropical Medicine University of Tübingen and German Center for Infection Research, Partner Site Tübingen Centre de Recherches Médicales de Lambaréné (CERMEL), Fondation Internationale de l'Hôpital Albert Schweitzer, Lambaréné, Gabon
| | - Benjamin Mordmüller
- Institute of Tropical Medicine University of Tübingen and German Center for Infection Research, Partner Site Tübingen
| | - Matthias Frank
- Institute of Tropical Medicine University of Tübingen and German Center for Infection Research, Partner Site Tübingen
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47
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Vembar SS, Droll D, Scherf A. Translational regulation in blood stages of the malaria parasite Plasmodium spp.: systems-wide studies pave the way. WILEY INTERDISCIPLINARY REVIEWS-RNA 2016; 7:772-792. [PMID: 27230797 PMCID: PMC5111744 DOI: 10.1002/wrna.1365] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Revised: 04/21/2016] [Accepted: 04/26/2016] [Indexed: 11/10/2022]
Abstract
The malaria parasite Plasmodium spp. varies the expression profile of its genes depending on the host it resides in and its developmental stage. Virtually all messenger RNA (mRNA) is expressed in a monocistronic manner, with transcriptional activation regulated at the epigenetic level and by specialized transcription factors. Furthermore, recent systems-wide studies have identified distinct mechanisms of post-transcriptional and translational control at various points of the parasite lifecycle. Taken together, it is evident that 'just-in-time' transcription and translation strategies coexist and coordinate protein expression during Plasmodium development, some of which we review here. In particular, we discuss global and specific mechanisms that control protein translation in blood stages of the human malaria parasite Plasmodium falciparum, once a cytoplasmic mRNA has been generated, and its crosstalk with mRNA decay and storage. We also focus on the widespread translational delay observed during the 48-hour blood stage lifecycle of P. falciparum-for over 30% of transcribed genes, including virulence factors required to invade erythrocytes-and its regulation by cis-elements in the mRNA, RNA-processing enzymes and RNA-binding proteins; the first-characterized amongst these are the DNA- and RNA-binding Alba proteins. More generally, we conclude that translational regulation is an emerging research field in malaria parasites and propose that its elucidation will not only shed light on the complex developmental program of this parasite, but may also reveal mechanisms contributing to drug resistance and define new targets for malaria intervention strategies. WIREs RNA 2016, 7:772-792. doi: 10.1002/wrna.1365 For further resources related to this article, please visit the WIREs website.
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Affiliation(s)
- Shruthi Sridhar Vembar
- Unité Biologie des Interactions Hôte-Parasite, Département de Parasites et Insectes Vecteurs, Institut Pasteur, Paris, France.
| | - Dorothea Droll
- Unité Biologie des Interactions Hôte-Parasite, Département de Parasites et Insectes Vecteurs, Institut Pasteur, Paris, France
| | - Artur Scherf
- Unité Biologie des Interactions Hôte-Parasite, Département de Parasites et Insectes Vecteurs, Institut Pasteur, Paris, France
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48
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Affiliation(s)
- Andrew P Waters
- Institute of Infection, Immunity and Inflammation, College of Medical Veterinary & Life Sciences and Wellcome Trust Centre for Molecular Parasitology, University of Glasgow, Scotland, United Kingdom
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49
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Judice CC, Bourgard C, Kayano ACAV, Albrecht L, Costa FTM. MicroRNAs in the Host-Apicomplexan Parasites Interactions: A Review of Immunopathological Aspects. Front Cell Infect Microbiol 2016; 6:5. [PMID: 26870701 PMCID: PMC4735398 DOI: 10.3389/fcimb.2016.00005] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Accepted: 01/13/2016] [Indexed: 01/08/2023] Open
Abstract
MicroRNAs (miRNAs), a class of small non-coding regulatory RNAs, have been detected in a variety of organisms ranging from ancient unicellular eukaryotes to mammals. They have been associated with numerous molecular mechanisms involving developmental, physiological and pathological changes of cells and tissues. Despite the fact that miRNA-silencing mechanisms appear to be absent in some Apicomplexan species, an increasing number of studies have reported a role for miRNAs in host-parasite interactions. Host miRNA expression can change following parasite infection and the consequences can lead, for instance, to parasite clearance. In this context, the immune system signaling appears to have a crucial role.
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Affiliation(s)
- Carla C Judice
- Laboratory of Tropical Diseases, Department of Genetics, Evolution and Bioagents, University of Campinas UNICAMP, Campinas, Brazil
| | - Catarina Bourgard
- Laboratory of Tropical Diseases, Department of Genetics, Evolution and Bioagents, University of Campinas UNICAMP, Campinas, Brazil
| | - Ana C A V Kayano
- Laboratory of Tropical Diseases, Department of Genetics, Evolution and Bioagents, University of Campinas UNICAMP, Campinas, Brazil
| | | | - Fabio T M Costa
- Laboratory of Tropical Diseases, Department of Genetics, Evolution and Bioagents, University of Campinas UNICAMP, Campinas, Brazil
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50
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Nuclease assisted target recycling and spherical nucleic acids gold nanoparticles recruitment for ultrasensitive detection of microRNA. Electrochim Acta 2016. [DOI: 10.1016/j.electacta.2016.01.034] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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