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Hadjimichael E, Deitsch KW. Variable surface antigen expression, virulence, and persistent infection by Plasmodium falciparum malaria parasites. Microbiol Mol Biol Rev 2025; 89:e0011423. [PMID: 39807932 PMCID: PMC11948492 DOI: 10.1128/mmbr.00114-23] [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: 01/16/2025] Open
Abstract
SUMMARYThe human malaria parasite Plasmodium falciparum is known for its ability to maintain lengthy infections that can extend for over a year. This property is derived from the parasite's capacity to continuously alter the antigens expressed on the surface of the infected red blood cell, thereby avoiding antibody recognition and immune destruction. The primary target of the immune system is an antigen called PfEMP1 that serves as a cell surface receptor and enables infected cells to adhere to the vascular endothelium and thus avoid filtration by the spleen. The parasite's genome encodes approximately 60 antigenically distinct forms of PfEMP1, each encoded by individual members of the multicopy var gene family. This provides the parasite with a repertoire of antigenic types that it systematically cycles through over the course of an infection, thereby maintaining an infection until the repertoire is exhausted. While this model of antigenic variation based on var gene switching explains the dynamics of acute infections in individuals with limited anti-malarial immunity, it fails to explain reports of chronic, asymptomatic infections that can last over a decade. Recent field studies have led to a re-evaluation of previous conclusions regarding the prevalence of chronic infections, and the application of new technologies has provided insights into the molecular mechanisms that enable chronic infections and how these processes evolved.
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Affiliation(s)
- Evi Hadjimichael
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, New York, USA
| | - Kirk W. Deitsch
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, New York, USA
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2
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Liang Q, Zhang S, Liu Z, Wang J, Yin H, Guan G, You C. Comparative genome-wide identification and characterization of SET domain-containing and JmjC domain-containing proteins in piroplasms. BMC Genomics 2024; 25:804. [PMID: 39187768 PMCID: PMC11346185 DOI: 10.1186/s12864-024-10731-2] [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: 05/07/2024] [Accepted: 08/21/2024] [Indexed: 08/28/2024] Open
Abstract
BACKGROUND SET domain-containing histone lysine methyltransferases (HKMTs) and JmjC domain-containing histone demethylases (JHDMs) are essential for maintaining dynamic changes in histone methylation across parasite development and infection. However, information on the HKMTs and JHDMs in human pathogenic piroplasms, such as Babesia duncani and Babesia microti, and in veterinary important pathogens, including Babesia bigemina, Babesia bovis, Theileria annulata and Theileria parva, is limited. RESULTS A total of 38 putative KMTs and eight JHDMs were identified using a comparative genomics approach. Phylogenetic analysis revealed that the putative KMTs can be divided into eight subgroups, while the JHDMs belong to the JARID subfamily, except for BdJmjC1 (BdWA1_000016) and TpJmjC1 (Tp Muguga_02g00471) which cluster with JmjC domain only subfamily members. The motifs of SET and JmjC domains are highly conserved among piroplasm species. Interspecies collinearity analysis provided insight into the evolutionary duplication events of some SET domain and JmjC domain gene families. Moreover, relative gene expression analysis by RT‒qPCR demonstrated that the putative KMT and JHDM gene families were differentially expressed in different intraerythrocytic developmental stages of B. duncani, suggesting their role in Apicomplexa parasite development. CONCLUSIONS Our study provides a theoretical foundation and guidance for understanding the basic characteristics of several important piroplasm KMT and JHDM families and their biological roles in parasite differentiation.
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Affiliation(s)
- Qindong Liang
- Laboratory Medicine Center, The Second Hospital & Clinical Medical School, Lanzhou University, Lanzhou, Gansu, 730030, P. R. China
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Science, Lanzhou, Gansu, 730046, P. R. China
| | - Shangdi Zhang
- Laboratory Medicine Center, The Second Hospital & Clinical Medical School, Lanzhou University, Lanzhou, Gansu, 730030, P. R. China
| | - Zeen Liu
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Science, Lanzhou, Gansu, 730046, P. R. China
| | - Jinming Wang
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Science, Lanzhou, Gansu, 730046, P. R. China
- State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu, 730000, P. R. China
| | - Hong Yin
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Science, Lanzhou, Gansu, 730046, P. R. China.
- Jiangsu Co-Innovation Center for the Prevention and Control of Important Animal Infectious Disease and Zoonose, Yangzhou University, Yangzhou, 225009, P. R. China.
| | - Guiquan Guan
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Science, Lanzhou, Gansu, 730046, P. R. China.
- State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu, 730000, P. R. China.
| | - Chongge You
- Laboratory Medicine Center, The Second Hospital & Clinical Medical School, Lanzhou University, Lanzhou, Gansu, 730030, P. R. China.
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3
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Andradi-Brown C, Wichers-Misterek JS, von Thien H, Höppner YD, Scholz JAM, Hansson H, Filtenborg Hocke E, Gilberger TW, Duffy MF, Lavstsen T, Baum J, Otto TD, Cunnington AJ, Bachmann A. A novel computational pipeline for var gene expression augments the discovery of changes in the Plasmodium falciparum transcriptome during transition from in vivo to short-term in vitro culture. eLife 2024; 12:RP87726. [PMID: 38270586 PMCID: PMC10945709 DOI: 10.7554/elife.87726] [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: 01/26/2024] Open
Abstract
The pathogenesis of severe Plasmodium falciparum malaria involves cytoadhesive microvascular sequestration of infected erythrocytes, mediated by P. falciparum erythrocyte membrane protein 1 (PfEMP1). PfEMP1 variants are encoded by the highly polymorphic family of var genes, the sequences of which are largely unknown in clinical samples. Previously, we published new approaches for var gene profiling and classification of predicted binding phenotypes in clinical P. falciparum isolates (Wichers et al., 2021), which represented a major technical advance. Building on this, we report here a novel method for var gene assembly and multidimensional quantification from RNA-sequencing that outperforms the earlier approach of Wichers et al., 2021, on both laboratory and clinical isolates across a combination of metrics. Importantly, the tool can interrogate the var transcriptome in context with the rest of the transcriptome and can be applied to enhance our understanding of the role of var genes in malaria pathogenesis. We applied this new method to investigate changes in var gene expression through early transition of parasite isolates to in vitro culture, using paired sets of ex vivo samples from our previous study, cultured for up to three generations. In parallel, changes in non-polymorphic core gene expression were investigated. Modest but unpredictable var gene switching and convergence towards var2csa were observed in culture, along with differential expression of 19% of the core transcriptome between paired ex vivo and generation 1 samples. Our results cast doubt on the validity of the common practice of using short-term cultured parasites to make inferences about in vivo phenotype and behaviour.
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Affiliation(s)
- Clare Andradi-Brown
- Section of Paediatric Infectious Disease, Department of Infectious Disease, Imperial College LondonLondonUnited Kingdom
- Department of Life Sciences, Imperial College London, South KensingtonLondonUnited Kingdom
- Centre for Paediatrics and Child Health, Imperial College LondonLondonUnited Kingdom
| | - Jan Stephan Wichers-Misterek
- Bernhard Nocht Institute for Tropical Medicine, Bernhard-Nocht-StrasseHamburgGermany
- Centre for Structural Systems BiologyHamburgGermany
- Biology Department, University of HamburgHamburgGermany
| | - Heidrun von Thien
- Bernhard Nocht Institute for Tropical Medicine, Bernhard-Nocht-StrasseHamburgGermany
- Centre for Structural Systems BiologyHamburgGermany
- Biology Department, University of HamburgHamburgGermany
| | - Yannick D Höppner
- Bernhard Nocht Institute for Tropical Medicine, Bernhard-Nocht-StrasseHamburgGermany
- Centre for Structural Systems BiologyHamburgGermany
- Biology Department, University of HamburgHamburgGermany
| | - Judith AM Scholz
- Bernhard Nocht Institute for Tropical Medicine, Bernhard-Nocht-StrasseHamburgGermany
| | - Helle Hansson
- Center for Medical Parasitology, Department of Immunology and Microbiology, University of CopenhagenCopenhagenDenmark
- Department of Infectious Diseases, Copenhagen University HospitalCopenhagenDenmark
| | - Emma Filtenborg Hocke
- Center for Medical Parasitology, Department of Immunology and Microbiology, University of CopenhagenCopenhagenDenmark
- Department of Infectious Diseases, Copenhagen University HospitalCopenhagenDenmark
| | - Tim Wolf Gilberger
- Bernhard Nocht Institute for Tropical Medicine, Bernhard-Nocht-StrasseHamburgGermany
- Centre for Structural Systems BiologyHamburgGermany
- Biology Department, University of HamburgHamburgGermany
| | - Michael F Duffy
- Department of Microbiology and Immunology, University of MelbourneMelbourneAustralia
| | - Thomas Lavstsen
- Center for Medical Parasitology, Department of Immunology and Microbiology, University of CopenhagenCopenhagenDenmark
- Department of Infectious Diseases, Copenhagen University HospitalCopenhagenDenmark
| | - Jake Baum
- Department of Life Sciences, Imperial College London, South KensingtonLondonUnited Kingdom
- School of Biomedical Sciences, Faculty of Medicine & Health, UNSW, KensingtonSydneyUnited Kingdom
| | - Thomas D Otto
- School of Infection & Immunity, MVLS, University of GlasgowGlasgowUnited Kingdom
| | - Aubrey J Cunnington
- Section of Paediatric Infectious Disease, Department of Infectious Disease, Imperial College LondonLondonUnited Kingdom
- Centre for Paediatrics and Child Health, Imperial College LondonLondonUnited Kingdom
| | - Anna Bachmann
- Bernhard Nocht Institute for Tropical Medicine, Bernhard-Nocht-StrasseHamburgGermany
- Centre for Structural Systems BiologyHamburgGermany
- Biology Department, University of HamburgHamburgGermany
- German Center for Infection Research (DZIF), partner site Hamburg-Borstel-Lübeck-RiemsHamburgGermany
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4
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Abstract
Plasmodium falciparum, the human malaria parasite, infects two hosts and various cell types, inducing distinct morphological and physiological changes in the parasite in response to different environmental conditions. These variations required the parasite to adapt and develop elaborate molecular mechanisms to ensure its spread and transmission. Recent findings have significantly improved our understanding of the regulation of gene expression in P. falciparum. Here, we provide an up-to-date overview of technologies used to highlight the transcriptomic adjustments occurring in the parasite throughout its life cycle. We also emphasize the complementary and complex epigenetic mechanisms regulating gene expression in malaria parasites. This review concludes with an outlook on the chromatin architecture, the remodeling systems, and how this 3D genome organization is critical in various biological processes.
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Affiliation(s)
- Thomas Hollin
- Department of Molecular, Cell and Systems Biology, University of California, Riverside, California, USA;
| | - Zeinab Chahine
- Department of Molecular, Cell and Systems Biology, University of California, Riverside, California, USA;
| | - Karine G Le Roch
- Department of Molecular, Cell and Systems Biology, University of California, Riverside, California, USA;
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5
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Batugedara G, Lu XM, Hristov B, Abel S, Chahine Z, Hollin T, Williams D, Wang T, Cort A, Lenz T, Thompson TA, Prudhomme J, Tripathi AK, Xu G, Cudini J, Dogga S, Lawniczak M, Noble WS, Sinnis P, Le Roch KG. Novel insights into the role of long non-coding RNA in the human malaria parasite, Plasmodium falciparum. Nat Commun 2023; 14:5086. [PMID: 37607941 PMCID: PMC10444892 DOI: 10.1038/s41467-023-40883-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Accepted: 08/10/2023] [Indexed: 08/24/2023] Open
Abstract
The complex life cycle of Plasmodium falciparum requires coordinated gene expression regulation to allow host cell invasion, transmission, and immune evasion. Increasing evidence now suggests a major role for epigenetic mechanisms in gene expression in the parasite. In eukaryotes, many lncRNAs have been identified to be pivotal regulators of genome structure and gene expression. To investigate the regulatory roles of lncRNAs in P. falciparum we explore the intergenic lncRNA distribution in nuclear and cytoplasmic subcellular locations. Using nascent RNA expression profiles, we identify a total of 1768 lncRNAs, of which 718 (~41%) are novels in P. falciparum. The subcellular localization and stage-specific expression of several putative lncRNAs are validated using RNA-FISH. Additionally, the genome-wide occupancy of several candidate nuclear lncRNAs is explored using ChIRP. The results reveal that lncRNA occupancy sites are focal and sequence-specific with a particular enrichment for several parasite-specific gene families, including those involved in pathogenesis and sexual differentiation. Genomic and phenotypic analysis of one specific lncRNA demonstrate its importance in sexual differentiation and reproduction. Our findings bring a new level of insight into the role of lncRNAs in pathogenicity, gene regulation and sexual differentiation, opening new avenues for targeted therapeutic strategies against the deadly malaria parasite.
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Affiliation(s)
- Gayani Batugedara
- Department of Molecular Cell and Systems Biology, University of California Riverside, Riverside, CA, 92521, USA
| | - Xueqing M Lu
- Department of Molecular Cell and Systems Biology, University of California Riverside, Riverside, CA, 92521, USA
| | - Borislav Hristov
- Department of Genome Sciences, University of Washington, Seattle, WA, 98195-5065, USA
| | - Steven Abel
- Department of Molecular Cell and Systems Biology, University of California Riverside, Riverside, CA, 92521, USA
| | - Zeinab Chahine
- Department of Molecular Cell and Systems Biology, University of California Riverside, Riverside, CA, 92521, USA
| | - Thomas Hollin
- Department of Molecular Cell and Systems Biology, University of California Riverside, Riverside, CA, 92521, USA
| | - Desiree Williams
- Department of Molecular Cell and Systems Biology, University of California Riverside, Riverside, CA, 92521, USA
| | - Tina Wang
- Department of Molecular Cell and Systems Biology, University of California Riverside, Riverside, CA, 92521, USA
| | - Anthony Cort
- Department of Molecular Cell and Systems Biology, University of California Riverside, Riverside, CA, 92521, USA
| | - Todd Lenz
- Department of Molecular Cell and Systems Biology, University of California Riverside, Riverside, CA, 92521, USA
| | - Trevor A Thompson
- Department of Molecular Cell and Systems Biology, University of California Riverside, Riverside, CA, 92521, USA
| | - Jacques Prudhomme
- Department of Molecular Cell and Systems Biology, University of California Riverside, Riverside, CA, 92521, USA
| | - Abhai K Tripathi
- Department of Molecular Microbiology and Immunology and the Johns Hopkins Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, 21205, USA
| | - Guoyue Xu
- Department of Molecular Microbiology and Immunology and the Johns Hopkins Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, 21205, USA
| | | | - Sunil Dogga
- Wellcome Sanger Institute, Hinxton, CB10 1SA, UK
| | | | | | - Photini Sinnis
- Department of Molecular Microbiology and Immunology and the Johns Hopkins Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, 21205, USA
| | - Karine G Le Roch
- Department of Molecular Cell and Systems Biology, University of California Riverside, Riverside, CA, 92521, USA.
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6
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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 PMCID: PMC11695068 DOI: 10.1016/j.pt.2023.03.016] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [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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7
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Schneider V, Visone J, Harris C, Florini F, Hadjimichael E, Zhang X, Gross M, Rhee K, Ben Mamoun C, Kafsack B, Deitsch K. The human malaria parasite Plasmodium falciparum can sense environmental changes and respond by antigenic switching. Proc Natl Acad Sci U S A 2023; 120:e2302152120. [PMID: 37068249 PMCID: PMC10151525 DOI: 10.1073/pnas.2302152120] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Accepted: 03/20/2023] [Indexed: 04/19/2023] Open
Abstract
The primary antigenic and virulence determinant of the human malaria parasite Plasmodium falciparum is a variant surface protein called PfEMP1. Different forms of PfEMP1 are encoded by a multicopy gene family called var, and switching between active genes enables the parasites to evade the antibody response of their human hosts. var gene switching is key for the maintenance of chronic infections; however, what controls switching is unknown, although it has been suggested to occur at a constant frequency with little or no environmental influence. var gene transcription is controlled epigenetically through the activity of histone methyltransferases (HMTs). Studies in model systems have shown that metabolism and epigenetic control of gene expression are linked through the availability of intracellular S-adenosylmethionine (SAM), the principal methyl donor in biological methylation modifications, which can fluctuate based on nutrient availability. To determine whether environmental conditions and changes in metabolism can influence var gene expression, P. falciparum was cultured in media with altered concentrations of nutrients involved in SAM metabolism. We found that conditions that influence lipid metabolism induce var gene switching, indicating that parasites can respond to changes in their environment by altering var gene expression patterns. Genetic modifications that directly modified expression of the enzymes that control SAM levels similarly led to profound changes in var gene expression, confirming that changes in SAM availability modulate var gene switching. These observations directly challenge the paradigm that antigenic variation in P. falciparum follows an intrinsic, programed switching rate, which operates independently of any external stimuli.
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Affiliation(s)
- Victoria M. Schneider
- Department of Microbiology and Immunology, Weill Cornell Medicine, Cornell University, Ithaca, NY14853
- Laboratory of Chemical Biology and Microbial Pathogenesis, Rockefeller University, New York, NY 10065
| | - Joseph E. Visone
- Department of Microbiology and Immunology, Weill Cornell Medicine, Cornell University, Ithaca, NY14853
| | - Chantal T. Harris
- Department of Microbiology and Immunology, Weill Cornell Medicine, Cornell University, Ithaca, NY14853
| | - Francesca Florini
- Department of Microbiology and Immunology, Weill Cornell Medicine, Cornell University, Ithaca, NY14853
| | - Evi Hadjimichael
- Department of Microbiology and Immunology, Weill Cornell Medicine, Cornell University, Ithaca, NY14853
| | - Xu Zhang
- Department of Microbiology and Immunology, Weill Cornell Medicine, Cornell University, Ithaca, NY14853
| | - Mackensie R. Gross
- Department of Microbiology and Immunology, Weill Cornell Medicine, Cornell University, Ithaca, NY14853
| | - Kyu Y. Rhee
- Department of Microbiology and Immunology, Weill Cornell Medicine, Cornell University, Ithaca, NY14853
- Division of Infectious Diseases, Department of Medicine, Weill Cornell Medicine, Cornell University, Ithaca, NY14853
| | - Choukri Ben Mamoun
- Section of Infectious Disease, Department of Microbial Pathogenesis, Yale School of Medicine, Yale University New Haven, CT 06510
| | - Björn F. C. Kafsack
- Department of Microbiology and Immunology, Weill Cornell Medicine, Cornell University, Ithaca, NY14853
| | - Kirk W. Deitsch
- Department of Microbiology and Immunology, Weill Cornell Medicine, Cornell University, Ithaca, NY14853
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8
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Zhang X, Florini F, Visone JE, Lionardi I, Gross MR, Patel V, Deitsch KW. A coordinated transcriptional switching network mediates antigenic variation of human malaria parasites. eLife 2022; 11:e83840. [PMID: 36515978 PMCID: PMC9833823 DOI: 10.7554/elife.83840] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 12/13/2022] [Indexed: 12/15/2022] Open
Abstract
Malaria parasites avoid immune clearance through their ability to systematically alter antigens exposed on the surface of infected red blood cells. This is accomplished by tightly regulated transcriptional control of individual members of a large, multicopy gene family called var and is the key to both the virulence and chronic nature of malaria infections. Expression of var genes is mutually exclusive and controlled epigenetically, however how large populations of parasites coordinate var gene switching to avoid premature exposure of the antigenic repertoire is unknown. Here, we provide evidence for a transcriptional network anchored by a universally conserved gene called var2csa that coordinates the switching process. We describe a structured switching bias that shifts overtime and could shape the pattern of var expression over the course of a lengthy infection. Our results provide an explanation for a previously mysterious aspect of malaria infections and shed light on how parasites possessing a relatively small repertoire of variant antigen-encoding genes can coordinate switching events to limit antigen exposure, thereby maintaining chronic infections.
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Affiliation(s)
- Xu Zhang
- Department of Microbiology and Immunology, Weill Cornell Medical CollegeNew YorkUnited States
| | - Francesca Florini
- Department of Microbiology and Immunology, Weill Cornell Medical CollegeNew YorkUnited States
| | - Joseph E Visone
- Department of Microbiology and Immunology, Weill Cornell Medical CollegeNew YorkUnited States
| | - Irina Lionardi
- Jill Roberts Center for Inflammatory Bowel Disease, Weill Cornell Medical CollegeNew YorkUnited States
| | - Mackensie R Gross
- Department of Microbiology and Immunology, Weill Cornell Medical CollegeNew YorkUnited States
| | - Valay Patel
- Department of Microbiology and Immunology, Weill Cornell Medical CollegeNew YorkUnited States
| | - Kirk W Deitsch
- Department of Microbiology and Immunology, Weill Cornell Medical CollegeNew YorkUnited States
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A nuclear redox sensor modulates gene activation and var switching in Plasmodium falciparum. Proc Natl Acad Sci U S A 2022; 119:e2201247119. [PMID: 35939693 PMCID: PMC9388093 DOI: 10.1073/pnas.2201247119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The virulence of Plasmodium falciparum, which causes the deadliest form of human malaria, is attributed to its ability to evade the human immune response. These parasites "choose" to express a single variant from a repertoire of surface antigens called PfEMP1, which are placed on the surface of the infected red cell. Immune evasion is achieved by switches in expression between var genes, each encoding a different PfEMP1 variant. While the mechanisms that regulate mutually exclusive expression of var genes are still elusive, antisense long-noncoding RNAs (lncRNAs) transcribed from the intron of the active var gene were implicated in the "choice" of the single active var gene. Here, we show that this lncRNA colocalizes with the site of var mRNA transcription and is anchored to the var locus via DNA:RNA interactions. We define the var lncRNA interactome and identify a redox sensor, P. falciparum thioredoxin peroxidase I (PfTPx-1), as one of the proteins associated with the var antisense lncRNA. We show that PfTPx-1 localizes to a nuclear subcompartment associated with active transcription on the nuclear periphery, in ring-stage parasite, when var transcription occurs. In addition, PfTPx-1 colocalizes with S-adenosylmethionine synthetase (PfSAMS) in the nucleus, and its overexpression leads to activation of var2csa, similar to overexpression of PfSAMS. Furthermore, we show that PfTPx-1 knockdown alters the var switch rate as well as activation of additional gene subsets. Taken together, our data indicate that nuclear PfTPx-1 plays a role in gene activation possibly by providing a redox-controlled nuclear microenvironment ideal for active transcription.
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The Plasmodium falciparum Nuclear Protein Phosphatase NIF4 Is Required for Efficient Merozoite Invasion and Regulates Artemisinin Sensitivity. mBio 2022; 13:e0189722. [PMID: 35938722 PMCID: PMC9426563 DOI: 10.1128/mbio.01897-22] [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] [Indexed: 11/20/2022] Open
Abstract
Artemisinin resistance in Plasmodium falciparum has been associated with a mutation in the NLI-interacting factor-like phosphatase PfNIF4, in addition to the mutations in the Kelch13 protein as the major determinant. We found that PfNIF4 was predominantly expressed at the schizont stage and localized in the nuclei of the parasite. To elucidate the functions of PfNIF4 in P. falciparum, we performed PfNIF4 knockdown (KD) using the inducible ribozyme system. PfNIF4 KD attenuated merozoite invasion and affected gametocytogenesis. PfNIF4 KD parasites also showed significantly increased in vitro susceptibility to artemisinins. Transcriptomic and proteomic analysis revealed that PfNIF4 KD led to the downregulation of gene categories involved in invasion and artemisinin resistance (e.g., mitochondrial function, membrane, and Kelch13 interactome) at the trophozoite and/or schizont stage. Consistent with PfNIF4 being a protein phosphatase, PfNIF4 KD resulted in an overall upregulation of the phosphoproteome of infected erythrocytes. Quantitative phosphoproteomic profiling identified a set of PfNIF4-regulated phosphoproteins with functional similarity to FCP1 substrates, particularly proteins involved in chromatin organization and transcriptional regulation. Specifically, we observed increased phosphorylation of Ser2/5 of the tandem repeats in the C-terminal domain (CTD) of RNA polymerase II (RNAPII) upon PfNIF4 KD. Furthermore, using the TurboID-based proteomic approach, we identified that PfNIF4 interacted with the RNAPII components, AP2-domain transcription factors, and chromatin-modifiers and binders. These findings suggest that PfNIF4 may act as the RNAPII CTD phosphatase, regulating the expression of general and parasite-specific cellular pathways during the blood-stage development.
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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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12
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Quinn JE, Jeninga MD, Limm K, Pareek K, Meißgeier T, Bachmann A, Duffy MF, Petter M. The Putative Bromodomain Protein PfBDP7 of the Human Malaria Parasite Plasmodium Falciparum Cooperates With PfBDP1 in the Silencing of Variant Surface Antigen Expression. Front Cell Dev Biol 2022; 10:816558. [PMID: 35493110 PMCID: PMC9039026 DOI: 10.3389/fcell.2022.816558] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 03/18/2022] [Indexed: 01/08/2023] Open
Abstract
Epigenetic regulation is a critical mechanism in controlling virulence, differentiation, and survival of the human malaria parasite Plasmodium (P.) falciparum. Bromodomain proteins contribute to this process by binding to acetylated lysine residues of histones and thereby targeting the gene regulatory machinery to gene promoters. A protein complex containing the P. falciparum bromodomain proteins (PfBDP) 1 and PfBDP2 (BDP1/BDP2 core complex) was previously shown to play an essential role for the correct transcription of invasion related genes. Here, we performed a functional characterization of a third component of this complex, which we dubbed PfBDP7, because structural modelling predicted a typical bromodomain fold. We confirmed that PfBDP7 is a nuclear protein that interacts with PfBDP1 at invasion gene promoters in mature schizont stage parasites and contributes to their transcription. Although partial depletion of PfBDP7 showed no significant effect on parasite viability, conditional knock down of either PfBDP7 or PfBDP1 resulted in the de-repression of variant surface antigens (VSA), which are important pathogenicity factors. This de-repression was evident both on mRNA and protein level. To understand the underlying mechanism, we mapped the genome wide binding sites of PfBDP7 by ChIPseq and showed that in early schizonts, PfBDP7 and PfBDP1 are commonly enriched in heterochromatic regions across the gene body of all VSA families, including genes coding for PfEMP1, RIFIN, STEVOR, and PfMC-2TM. This suggests that PfBDP7 and PfBDP1 contribute to the silencing of VSAs by associating with heterochromatin. In conclusion, we identified PfBDP7 as a chromatin binding protein that is a constitutive part of the P. falciparum BDP1/BDP2 core complex and established PfBDP1 and PfBDP7 as novel players in the silencing of heterochromatin regulated virulence gene families of the malaria parasite P. falciparum.
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Affiliation(s)
- Jennifer E. Quinn
- Mikrobiologisches Institut—Klinische Mikrobiologie, Immunologie und Hygiene, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität (FAU) Erlangen-Nürnberg, Erlangen, Germany
| | - Myriam D. Jeninga
- Mikrobiologisches Institut—Klinische Mikrobiologie, Immunologie und Hygiene, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität (FAU) Erlangen-Nürnberg, Erlangen, Germany
| | - Katharina Limm
- Institute of Functional Genomics, University of Regensburg, Regensburg, Germany
| | - Kapil Pareek
- Mikrobiologisches Institut—Klinische Mikrobiologie, Immunologie und Hygiene, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität (FAU) Erlangen-Nürnberg, Erlangen, Germany
| | - Tina Meißgeier
- Mikrobiologisches Institut—Klinische Mikrobiologie, Immunologie und Hygiene, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität (FAU) Erlangen-Nürnberg, Erlangen, Germany
| | - Anna Bachmann
- Department of Cellular Parasitology, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
- Centre for Structural Systems Biology (CSSB), Hamburg, Germany
- Biology Department, University of Hamburg, Hamburg, Germany
| | - Michael F. Duffy
- Department of Microbiology and Immunology, The University of Melbourne, Bio21 Institute, Parkville, VIC, Australia
| | - Michaela Petter
- Mikrobiologisches Institut—Klinische Mikrobiologie, Immunologie und Hygiene, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität (FAU) Erlangen-Nürnberg, Erlangen, Germany
- Department of Medicine, The University of Melbourne, Royal Melbourne Hospital, Parkville, VIC, Australia
- *Correspondence: Michaela Petter,
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13
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Connacher J, von Grüning H, Birkholtz L. Histone Modification Landscapes as a Roadmap for Malaria Parasite Development. Front Cell Dev Biol 2022; 10:848797. [PMID: 35433676 PMCID: PMC9010790 DOI: 10.3389/fcell.2022.848797] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Accepted: 03/04/2022] [Indexed: 12/26/2022] Open
Abstract
Plasmodium falciparum remains the deadliest parasite species in the world, responsible for 229 million cases of human malaria in 2019. The ability of the P. falciparum parasite to progress through multiple life cycle stages and thrive in diverse host and vector species hinges on sophisticated mechanisms of epigenetic regulation of gene expression. Emerging evidence indicates such epigenetic control exists in concentric layers, revolving around core histone post-translational modification (PTM) landscapes. Here, we provide a necessary update of recent epigenome research in malaria parasites, focusing specifically on the ability of dynamic histone PTM landscapes to orchestrate the divergent development and differentiation pathways in P. falciparum parasites. In addition to individual histone PTMs, we discuss recent findings that imply functional importance for combinatorial PTMs in P. falciparum parasites, representing an operational histone code. Finally, this review highlights the remaining gaps and provides strategies to address these to obtain a more thorough understanding of the histone modification landscapes that are at the center of epigenetic regulation in human malaria parasites.
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14
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Florini F, Visone JE, Deitsch KW. Shared Mechanisms for Mutually Exclusive Expression and Antigenic Variation by Protozoan Parasites. Front Cell Dev Biol 2022; 10:852239. [PMID: 35350381 PMCID: PMC8957917 DOI: 10.3389/fcell.2022.852239] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 02/17/2022] [Indexed: 01/05/2023] Open
Abstract
Cellular decision-making at the level of gene expression is a key process in the development and evolution of every organism. Variations in gene expression can lead to phenotypic diversity and the development of subpopulations with adaptive advantages. A prime example is the mutually exclusive activation of a single gene from within a multicopy gene family. In mammals, this ranges from the activation of one of the two immunoglobulin (Ig) alleles to the choice in olfactory sensory neurons of a single odorant receptor (OR) gene from a family of more than 1,000. Similarly, in parasites like Trypanosoma brucei, Giardia lamblia or Plasmodium falciparum, the process of antigenic variation required to escape recognition by the host immune system involves the monoallelic expression of vsg, vsp or var genes, respectively. Despite the importance of this process, understanding how this choice is made remains an enigma. The development of powerful techniques such as single cell RNA-seq and Hi-C has provided new insights into the mechanisms these different systems employ to achieve monoallelic gene expression. Studies utilizing these techniques have shown how the complex interplay between nuclear architecture, physical interactions between chromosomes and different chromatin states lead to single allele expression. Additionally, in several instances it has been observed that high-level expression of a single gene is preceded by a transient state where multiple genes are expressed at a low level. In this review, we will describe and compare the different strategies that organisms have evolved to choose one gene from within a large family and how parasites employ this strategy to ensure survival within their hosts.
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Affiliation(s)
| | | | - Kirk W. Deitsch
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, NY, United States
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15
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Ngwa CJ, Farrukh A, Pradel G. Zinc finger proteins of Plasmodium falciparum. Cell Microbiol 2021; 23:e13387. [PMID: 34418264 DOI: 10.1111/cmi.13387] [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: 04/29/2021] [Revised: 07/19/2021] [Accepted: 07/24/2021] [Indexed: 01/14/2023]
Abstract
Zinc finger proteins (ZFPs) are a large diverse family of proteins with one or more zinc finger domains in which zinc is important in stabilising the domain. ZFPs can interact with DNA, RNA, lipids or even other proteins and therefore contribute to diverse cellular processes including transcriptional regulation, ubiquitin-mediated protein degradation, mRNA decay and stability. In this review, we provide the first comprehensive classification of ZFPs of the malaria parasite Plasmodium falciparum and provide a state of knowledge on the main ZFPs in the parasite, which include the C2H2, CCCH, RING finger and the PHD finger proteins. TAKE AWAYS: The Plasmodium falciparum genome encodes 170 putative Zinc finger proteins (ZFPs). The C2H2, CCCH, RING finger and PHD finger subfamilies of ZFPs are most represented. Known ZFP functions include the regulation of mRNA metabolism and proteostasis.
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Affiliation(s)
- Che Julius Ngwa
- Division of Cellular and Applied Infection Biology, Institute of Zoology, RWTH Aachen University, Aachen, Germany
| | - Afia Farrukh
- Division of Cellular and Applied Infection Biology, Institute of Zoology, RWTH Aachen University, Aachen, Germany
| | - Gabriele Pradel
- Division of Cellular and Applied Infection Biology, Institute of Zoology, RWTH Aachen University, Aachen, Germany
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16
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Sethumadhavan DV, Govindaraju G, Jabeena CA, Rajavelu A. Plasmodium falciparum SET2 domain is allosterically regulated by its PHD-like domain to methylate at H3K36. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2021; 1864:194744. [PMID: 34389510 DOI: 10.1016/j.bbagrm.2021.194744] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 06/13/2021] [Revised: 08/02/2021] [Accepted: 08/03/2021] [Indexed: 11/24/2022]
Abstract
The antigenic variation is an essential mechanism employed by the malaria parasite to establish a chronic infection in humans. Three major virulent proteins EMP1, RIFINs, and STEVOR have been implicated in contributing to the antigenic variation process and are encoded by multigene families in Plasmodium spp. The key virulence factor PfEMP1 is encoded by var genes, and it exhibits a mutually exclusive transcriptional switching between var genes, ensuring an individual parasite only transcribes a single var gene at a time. Expression of var genes is tightly regulated by two histone epigenetic methylation marks H3K36me3 and H3K9me3, of which the H3K36me3 mark is highly enriched on transcription start sites (TSSs) of suppressed var genes in P. falciparum. However, the mechanisms of H3K36me3 mark propagation on all the 59 var genes of P. falciparum are not known. Here, we have identified a PHD (Plant Homeodomain-like Domain) like domain present within the PfSET2 protein that specifically binds to the H3K36me2 mark, an intermediate product of the H3K36me3 mark formation on the nucleosome. Surprisingly, we have found that PHD - H3K36me2 interaction leads to stimulation of SET2 domain activity on the nucleosome substrates. The allosteric stimulation of the PfSET2 domain by PHD-like domain present within the same protein suggests a novel mechanism of H3K36me3 mark propagation on var genes of P. falciparum. This study proposes allosteric regulation of PfSET2 protein by H3K36me2 mark as an essential mechanism of var genes suppression to ensure successful antigenic variation by the malaria parasite.
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Affiliation(s)
- Devadathan Valiyamangalath Sethumadhavan
- Pathogen Biology, Rajiv Gandhi Centre for Biotechnology (RGCB), Thycaud PO, Thiruvananthapuram-, 695014, Kerala, India; Ph.D registered with Manipal Academy of Higher Education (MAHE), Tiger Circle Road, Madhav Nagar, Manipal, Karnataka, 576104, India
| | - Gayathri Govindaraju
- Pathogen Biology, Rajiv Gandhi Centre for Biotechnology (RGCB), Thycaud PO, Thiruvananthapuram-, 695014, Kerala, India; Ph.D registered with Manipal Academy of Higher Education (MAHE), Tiger Circle Road, Madhav Nagar, Manipal, Karnataka, 576104, India
| | - C A Jabeena
- Pathogen Biology, Rajiv Gandhi Centre for Biotechnology (RGCB), Thycaud PO, Thiruvananthapuram-, 695014, Kerala, India; Ph.D registered with Manipal Academy of Higher Education (MAHE), Tiger Circle Road, Madhav Nagar, Manipal, Karnataka, 576104, India
| | - Arumugam Rajavelu
- Pathogen Biology, Rajiv Gandhi Centre for Biotechnology (RGCB), Thycaud PO, Thiruvananthapuram-, 695014, Kerala, India; Department of Biotechnology, Bhupat & Jyoti Mehta School of Biosciences, Indian Institute of Technology, Madras, Chennai, 600 036, India.
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17
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Gross MR, Hsu R, Deitsch KW. Evolution of transcriptional control of antigenic variation and virulence in human and ape malaria parasites. BMC Ecol Evol 2021; 21:139. [PMID: 34238209 PMCID: PMC8265125 DOI: 10.1186/s12862-021-01872-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Accepted: 07/02/2021] [Indexed: 11/13/2022] Open
Abstract
Background The most severe form of human malaria is caused by the protozoan parasite Plasmodium falciparum. This unicellular organism is a member of a subgenus of Plasmodium called the Laverania that infects apes, with P. falciparum being the only member that infects humans. The exceptional virulence of this species to humans can be largely attributed to a family of variant surface antigens placed by the parasites onto the surface of infected red blood cells that mediate adherence to the vascular endothelium. These proteins are encoded by a large, multicopy gene family called var, with each var gene encoding a different form of the protein. By changing which var gene is expressed, parasites avoid immune recognition, a process called antigenic variation that underlies the chronic nature of malaria infections. Results Here we show that the common ancestor of the branch of the Laverania lineage that includes the human parasite underwent a remarkable change in the organization and structure of elements linked to the complex transcriptional regulation displayed by the var gene family. Unlike the other members of the Laverania, the clade that gave rise to P. falciparum evolved distinct subsets of var genes distinguishable by different upstream transcriptional regulatory regions that have been associated with different expression profiles and virulence properties. In addition, two uniquely conserved var genes that have been proposed to play a role in coordinating transcriptional switching similarly arose uniquely within this clade. We hypothesize that these changes originated at a time of dramatic climatic change on the African continent that is predicted to have led to significant changes in transmission dynamics, thus selecting for patterns of antigenic variation that enabled lengthier, more chronic infections. Conclusions These observations suggest that changes in transmission dynamics selected for significant alterations in the transcriptional regulatory mechanisms that mediate antigenic variation in the parasite lineage that includes P. falciparum. These changes likely underlie the chronic nature of these infections as well as their exceptional virulence. Supplementary Information The online version contains supplementary material available at 10.1186/s12862-021-01872-z.
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Affiliation(s)
- Mackensie R Gross
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, NY, USA
| | - Rosie Hsu
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, NY, USA
| | - Kirk W Deitsch
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, NY, USA.
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18
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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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19
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Peculiarities of Plasmodium falciparum Gene Regulation and Chromatin Structure. Int J Mol Sci 2021; 22:ijms22105168. [PMID: 34068393 PMCID: PMC8153576 DOI: 10.3390/ijms22105168] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 05/10/2021] [Accepted: 05/10/2021] [Indexed: 12/14/2022] Open
Abstract
The highly complex life cycle of the human malaria parasite, Plasmodium falciparum, is based on an orchestrated and tightly regulated gene expression program. In general, eukaryotic transcription regulation is determined by a combination of sequence-specific transcription factors binding to regulatory DNA elements and the packaging of DNA into chromatin as an additional layer. The accessibility of regulatory DNA elements is controlled by the nucleosome occupancy and changes of their positions by an active process called nucleosome remodeling. These epigenetic mechanisms are poorly explored in P. falciparum. The parasite genome is characterized by an extraordinarily high AT-content and the distinct architecture of functional elements, and chromatin-related proteins also exhibit high sequence divergence compared to other eukaryotes. Together with the distinct biochemical properties of nucleosomes, these features suggest substantial differences in chromatin-dependent regulation. Here, we highlight the peculiarities of epigenetic mechanisms in P. falciparum, addressing chromatin structure and dynamics with respect to their impact on transcriptional control. We focus on the specialized chromatin remodeling enzymes and discuss their essential function in P. falciparum gene regulation.
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20
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Connacher J, Josling GA, Orchard LM, Reader J, Llinás M, Birkholtz LM. H3K36 methylation reprograms gene expression to drive early gametocyte development in Plasmodium falciparum. Epigenetics Chromatin 2021; 14:19. [PMID: 33794978 PMCID: PMC8017609 DOI: 10.1186/s13072-021-00393-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 03/26/2021] [Indexed: 12/12/2022] Open
Abstract
Background The Plasmodium sexual gametocyte stages are the only transmissible form of the malaria parasite and are thus responsible for the continued transmission of the disease. Gametocytes undergo extensive functional and morphological changes from commitment to maturity, directed by an equally extensive control program. However, the processes that drive the differentiation and development of the gametocyte post-commitment, remain largely unexplored. A previous study reported enrichment of H3K36 di- and tri-methylated (H3K36me2&3) histones in early-stage gametocytes. Using chromatin immunoprecipitation followed by high-throughput sequencing, we identify a stage-specific association between these repressive histone modifications and transcriptional reprogramming that define a stage II gametocyte transition point. Results Here, we show that H3K36me2 and H3K36me3 from stage II gametocytes are associated with repression of genes involved in asexual proliferation and sexual commitment, indicating that H3K36me2&3-mediated repression of such genes is essential to the transition from early gametocyte differentiation to intermediate development. Importantly, we show that the gene encoding the transcription factor AP2-G as commitment master regulator is enriched with H3K36me2&3 and actively repressed in stage II gametocytes, providing the first evidence of ap2-g gene repression in post-commitment gametocytes. Lastly, we associate the enhanced potency of the pan-selective Jumonji inhibitor JIB-04 in gametocytes with the inhibition of histone demethylation including H3K36me2&3 and a disruption of normal transcriptional programs. Conclusions Taken together, our results provide the first description of an association between global gene expression reprogramming and histone post-translational modifications during P. falciparum early sexual development. The stage II gametocyte-specific abundance of H3K36me2&3 manifests predominantly as an independent regulatory mechanism targeted towards genes that are repressed post-commitment. H3K36me2&3-associated repression of genes is therefore involved in key transcriptional shifts that accompany the transition from early gametocyte differentiation to intermediate development. Supplementary Information The online version contains supplementary material available at 10.1186/s13072-021-00393-9.
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Affiliation(s)
- Jessica Connacher
- Department of Biochemistry, Genetics and Microbiology, Institute for Sustainable Malaria Control, University of Pretoria, Private Bag x20, Hatfield, 0028, South Africa
| | - Gabrielle A Josling
- Department of Biochemistry & Molecular Biology and the Huck Center for Malaria Research, Pennsylvania State University, University Park, PA, 16802, USA
| | - Lindsey M Orchard
- Department of Biochemistry & Molecular Biology and the Huck Center for Malaria Research, Pennsylvania State University, University Park, PA, 16802, USA
| | - Janette Reader
- Department of Biochemistry, Genetics and Microbiology, Institute for Sustainable Malaria Control, University of Pretoria, Private Bag x20, Hatfield, 0028, South Africa
| | - Manuel Llinás
- Department of Biochemistry & Molecular Biology and the Huck Center for Malaria Research, Pennsylvania State University, University Park, PA, 16802, USA.,Department of Chemistry, Pennsylvania State University, University Park, PA, 16802, USA
| | - Lyn-Marié Birkholtz
- Department of Biochemistry, Genetics and Microbiology, Institute for Sustainable Malaria Control, University of Pretoria, Private Bag x20, Hatfield, 0028, South Africa.
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21
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Hollin T, Le Roch KG. From Genes to Transcripts, a Tightly Regulated Journey in Plasmodium. Front Cell Infect Microbiol 2020; 10:618454. [PMID: 33425787 PMCID: PMC7793691 DOI: 10.3389/fcimb.2020.618454] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2020] [Accepted: 11/19/2020] [Indexed: 12/17/2022] Open
Abstract
Over the past decade, we have witnessed significant progresses in understanding gene regulation in Apicomplexa including the human malaria parasite, Plasmodium falciparum. This parasite possesses the ability to convert in multiple stages in various hosts, cell types, and environments. Recent findings indicate that P. falciparum is talented at using efficient and complementary molecular mechanisms to ensure a tight control of gene expression at each stage of its life cycle. Here, we review the current understanding on the contribution of the epigenome, atypical transcription factors, and chromatin organization to regulate stage conversion in P. falciparum. The adjustment of these regulatory mechanisms occurring during the progression of the life cycle will be extensively discussed.
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Affiliation(s)
- Thomas Hollin
- Department of Molecular, Cell and Systems Biology, University of California Riverside, CA, United States
| | - Karine G Le Roch
- Department of Molecular, Cell and Systems Biology, University of California Riverside, CA, United States
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22
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Li Y, Baptista RP, Kissinger JC. Noncoding RNAs in Apicomplexan Parasites: An Update. Trends Parasitol 2020; 36:835-849. [DOI: 10.1016/j.pt.2020.07.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Revised: 06/26/2020] [Accepted: 07/18/2020] [Indexed: 12/16/2022]
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23
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Dynamic Chromatin Structure and Epigenetics Control the Fate of Malaria Parasites. Trends Genet 2020; 37:73-85. [PMID: 32988634 DOI: 10.1016/j.tig.2020.09.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 08/27/2020] [Accepted: 09/02/2020] [Indexed: 12/11/2022]
Abstract
Multiple hosts and various life cycle stages prompt the human malaria parasite, Plasmodium falciparum, to acquire sophisticated molecular mechanisms to ensure its survival, spread, and transmission to its next host. To face these environmental challenges, increasing evidence suggests that the parasite has developed complex and complementary layers of regulatory mechanisms controlling gene expression. Here, we discuss the recent developments in the discovery of molecular components that contribute to cell replication and differentiation and highlight the major contributions of epigenetics, transcription factors, and nuclear architecture in controlling gene regulation and life cycle progression in Plasmodium spp.
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24
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Bryant JM, Baumgarten S, Dingli F, Loew D, Sinha A, Claës A, Preiser PR, Dedon PC, Scherf A. Exploring the virulence gene interactome with CRISPR/dCas9 in the human malaria parasite. Mol Syst Biol 2020; 16:e9569. [PMID: 32816370 PMCID: PMC7440042 DOI: 10.15252/msb.20209569] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 07/17/2020] [Accepted: 07/22/2020] [Indexed: 12/13/2022] Open
Abstract
Mutually exclusive expression of the var multigene family is key to immune evasion and pathogenesis in Plasmodium falciparum, but few factors have been shown to play a direct role. We adapted a CRISPR-based proteomics approach to identify novel factors associated with var genes in their natural chromatin context. Catalytically inactive Cas9 ("dCas9") was targeted to var gene regulatory elements, immunoprecipitated, and analyzed with mass spectrometry. Known and novel factors were enriched including structural proteins, DNA helicases, and chromatin remodelers. Functional characterization of PfISWI, an evolutionarily divergent putative chromatin remodeler enriched at the var gene promoter, revealed a role in transcriptional activation. Proteomics of PfISWI identified several proteins enriched at the var gene promoter such as acetyl-CoA synthetase, a putative MORC protein, and an ApiAP2 transcription factor. These findings validate the CRISPR/dCas9 proteomics method and define a new var gene-associated chromatin complex. This study establishes a tool for targeted chromatin purification of unaltered genomic loci and identifies novel chromatin-associated factors potentially involved in transcriptional control and/or chromatin organization of virulence genes in the human malaria parasite.
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Affiliation(s)
- Jessica M Bryant
- Biology of Host‐Parasite Interactions UnitInstitut PasteurParisFrance
- INSERM U1201ParisFrance
- CNRS ERL9195ParisFrance
| | - Sebastian Baumgarten
- Biology of Host‐Parasite Interactions UnitInstitut PasteurParisFrance
- INSERM U1201ParisFrance
- CNRS ERL9195ParisFrance
| | - Florent Dingli
- Institut CuriePSL Research UniversityCentre de RechercheMass Spectrometry and Proteomics FacilityParisFrance
| | - Damarys Loew
- Institut CuriePSL Research UniversityCentre de RechercheMass Spectrometry and Proteomics FacilityParisFrance
| | - Ameya Sinha
- School of Biological SciencesNanyang Technological UniversitySingaporeSingapore
- Antimicrobial Resistance Interdisciplinary Research GroupSingapore‐MIT Alliance for Research and TechnologySingaporeSingapore
| | - Aurélie Claës
- Biology of Host‐Parasite Interactions UnitInstitut PasteurParisFrance
- INSERM U1201ParisFrance
- CNRS ERL9195ParisFrance
| | - Peter R Preiser
- School of Biological SciencesNanyang Technological UniversitySingaporeSingapore
- Antimicrobial Resistance Interdisciplinary Research GroupSingapore‐MIT Alliance for Research and TechnologySingaporeSingapore
| | - Peter C Dedon
- Antimicrobial Resistance Interdisciplinary Research GroupSingapore‐MIT Alliance for Research and TechnologySingaporeSingapore
- Department of Biological EngineeringMassachusetts Institute of TechnologyCambridgeMAUSA
| | - Artur Scherf
- Biology of Host‐Parasite Interactions UnitInstitut PasteurParisFrance
- INSERM U1201ParisFrance
- CNRS ERL9195ParisFrance
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25
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Matthews KA, Senagbe KM, Nötzel C, Gonzales CA, Tong X, Rijo-Ferreira F, Bhanu NV, Miguel-Blanco C, Lafuente-Monasterio MJ, Garcia BA, Kafsack BFC, Martinez ED. Disruption of the Plasmodium falciparum Life Cycle through Transcriptional Reprogramming by Inhibitors of Jumonji Demethylases. ACS Infect Dis 2020; 6:1058-1075. [PMID: 32272012 PMCID: PMC7748244 DOI: 10.1021/acsinfecdis.9b00455] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
![]()
Little
is known about the role of the three Jumonji C (JmjC) enzymes
in Plasmodium falciparum (Pf). Here,
we show that JIB-04 and other established inhibitors of mammalian
JmjC histone demethylases kill asexual blood stage parasites and are
even more potent at blocking gametocyte development and gamete formation.
In late stage parasites, JIB-04 increased levels of trimethylated
lysine residues on histones, suggesting the inhibition of P. falciparum Jumonji demethylase activity. These epigenetic
defects coincide with deregulation of invasion, cell motor, and sexual
development gene programs, including gene targets coregulated by the
PfAP2-I transcription factor and chromatin-binding factor, PfBDP1.
Mechanistically, we demonstrate that PfJmj3 converts 2-oxoglutarate
to succinate in an iron-dependent manner consistent with mammalian
Jumonji enzymes, and this catalytic activity is inhibited by JIB-04
and other Jumonji inhibitors. Our pharmacological studies of Jumonji
activity in the malaria parasite provide evidence that inhibition
of these enzymatic activities is detrimental to the parasite.
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Affiliation(s)
- Krista A. Matthews
- Department of Pharmacology, The University of Texas Southwestern Medical Center, 6000 Harry Hines Blvd., Dallas, Texas 75390, United States
| | - Kossi M. Senagbe
- Hamon Center for Therapeutic Oncology Research, The University of Texas Southwestern Medical Center, 6000 Harry Hines Blvd., Dallas, Texas 75390, United States
| | - Christopher Nötzel
- Department of Microbiology & Immunology, Weill Cornell Medicine, 1300 York Avenue, W-705, New York, New York 10065, United States
- Biochemistry, Cell & Molecular Biology Graduate Program, Weill Cornell Medicine, 1300 York Avenue, W-705, New York, New York 10065, United States
| | - Christopher A. Gonzales
- Hamon Center for Therapeutic Oncology Research, The University of Texas Southwestern Medical Center, 6000 Harry Hines Blvd., Dallas, Texas 75390, United States
| | - Xinran Tong
- Department of Microbiology & Immunology, Weill Cornell Medicine, 1300 York Avenue, W-705, New York, New York 10065, United States
| | - Filipa Rijo-Ferreira
- Department of Neuroscience, The University of Texas Southwestern Medical Center, 6000 Harry Hines Blvd., Dallas, Texas 75390, United States
| | - Natarajan V. Bhanu
- Epigenetics Program, Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, 3400 Civic Center Blvd., Bldg. 421, Philadelphia, Pennsylvania 19104, United States
| | - Celia Miguel-Blanco
- Tres Cantos Medicines Development Campus, GlaxoSmithKline, P.T.M. Severo Ochoa, Tres Cantos, Madrid 28760, Spain
| | | | - Benjamin A. Garcia
- Epigenetics Program, Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, 3400 Civic Center Blvd., Bldg. 421, Philadelphia, Pennsylvania 19104, United States
| | - Björn F. C. Kafsack
- Department of Microbiology & Immunology, Weill Cornell Medicine, 1300 York Avenue, W-705, New York, New York 10065, United States
- Biochemistry, Cell & Molecular Biology Graduate Program, Weill Cornell Medicine, 1300 York Avenue, W-705, New York, New York 10065, United States
| | - Elisabeth D. Martinez
- Department of Pharmacology, The University of Texas Southwestern Medical Center, 6000 Harry Hines Blvd., Dallas, Texas 75390, United States
- Hamon Center for Therapeutic Oncology Research, The University of Texas Southwestern Medical Center, 6000 Harry Hines Blvd., Dallas, Texas 75390, United States
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Kirkman LA, Deitsch KW. Vive la Différence: Exploiting the Differences between Rodent and Human Malarias. Trends Parasitol 2020; 36:504-511. [PMID: 32407681 DOI: 10.1016/j.pt.2020.03.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Revised: 03/23/2020] [Accepted: 03/23/2020] [Indexed: 12/14/2022]
Abstract
Experimental research into malaria biology and pathogenesis has historically focused on two model systems, in vitro culture of the human parasite Plasmodium falciparum and in vivo infections of laboratory animals using rodent parasites. While there is clear value in having a manipulatable animal model for studying malaria, there have occasionally been controversies around how representative the rodent model is of the human disease, and therefore significant emphasis has been placed on the similarities between the two biological systems. By focusing on basic nuclear functions, we wish to highlight that identifying key differences in the parasites and their interactions with their mammalian hosts can be equally informative and provide remarkable insights into the biology and evolution of these important infectious organisms.
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Affiliation(s)
- Laura A Kirkman
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, NY, USA; Department of Internal Medicine, Division of Infectious Diseases, Weill Cornell Medical College, New York, NY, USA
| | - Kirk W Deitsch
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, NY, USA.
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27
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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: 17] [Impact Index Per Article: 3.4] [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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28
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Lenz T, Le Roch KG. Three-Dimensional Genome Organization and Virulence in Apicomplexan Parasites. Epigenet Insights 2019; 12:2516865719879436. [PMID: 31633082 PMCID: PMC6769224 DOI: 10.1177/2516865719879436] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Accepted: 09/06/2019] [Indexed: 12/19/2022] Open
Abstract
Mounting evidence supports the idea that epigenetic, and the overall 3-dimensional (3D) architecture of the genome, plays an important role in gene expression for eukaryotic organisms. We recently used Hi-C methodologies to generate and compare the 3D genome of 7 different apicomplexan parasites, including several pathogenic and less pathogenic malaria parasites as well as related human parasites Babesia microti and Toxoplasma gondii. Our goal was to understand the possible relationship between genome organization, gene expression, and pathogenicity of these infectious agents. Collectively, our results demonstrate that spatial genome organization in most Plasmodium species is constrained by the colocalization of virulence genes that are unique in their effect on chromosome folding, indicating a link between genome organization and gene expression in more virulent pathogens.
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Affiliation(s)
- Todd Lenz
- Department of Molecular, Cell and Systems Biology (MCSB), University of California, Riverside, Riverside, CA, USA
| | - Karine G Le Roch
- Department of Molecular, Cell and Systems Biology (MCSB), University of California, Riverside, Riverside, CA, USA
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29
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Abel S, Le Roch KG. The role of epigenetics and chromatin structure in transcriptional regulation in malaria parasites. Brief Funct Genomics 2019; 18:302-313. [PMID: 31220857 PMCID: PMC6859822 DOI: 10.1093/bfgp/elz005] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Revised: 02/25/2019] [Accepted: 03/14/2019] [Indexed: 12/28/2022] Open
Abstract
Due to the unique selective pressures and extreme changes faced by the human malaria parasite Plasmodium falciparum throughout its life cycle, the parasite has evolved distinct features to alter its gene expression patterns. Along with classical gene regulation by transcription factors (TFs), of which only one family, the AP2 TFs, has been described in the parasite genome, a large body of evidence points toward chromatin structure and epigenetic factors mediating the changes in gene expression associated with parasite life cycle stages. These attributes may be critically important for immune evasion, host cell invasion and development of the parasite in its two hosts, the human and the Anopheles vector. Thus, the factors involved in the maintenance and regulation of chromatin and epigenetic features represent potential targets for antimalarial drugs. In this review, we discuss the mechanisms in P. falciparum that regulate chromatin structure, nucleosome landscape, the 3-dimensional structure of the genome and additional distinctive features created by parasite-specific genes and gene families. We review conserved traits of chromatin in eukaryotes in order to highlight what is unique in the parasite.
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Affiliation(s)
- Steven Abel
- Department of Molecular, Cell and Systems Biology, University of California Riverside, Riverside, CA, USA
| | - Karine G Le Roch
- Department of Molecular, Cell and Systems Biology, University of California Riverside, Riverside, CA, USA
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30
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Abstract
The positioning of chromosomes in the nucleus of a eukaryotic cell is highly organized and has a complex and dynamic relationship with gene expression. In the human malaria parasite Plasmodium falciparum, the clustering of a family of virulence genes correlates with their coordinated silencing and has a strong influence on the overall organization of the genome. To identify conserved and species-specific principles of genome organization, we performed Hi-C experiments and generated 3D genome models for five Plasmodium species and two related apicomplexan parasites. Plasmodium species mainly showed clustering of centromeres, telomeres, and virulence genes. In P. falciparum, the heterochromatic virulence gene cluster had a strong repressive effect on the surrounding nuclear space, while this was less pronounced in Plasmodium vivax and Plasmodium berghei, and absent in Plasmodium yoelii In Plasmodium knowlesi, telomeres and virulence genes were more dispersed throughout the nucleus, but its 3D genome showed a strong correlation with gene expression. The Babesia microti genome showed a classical Rabl organization with colocalization of subtelomeric virulence genes, while the Toxoplasma gondii genome was dominated by clustering of the centromeres and lacked virulence gene clustering. Collectively, our results demonstrate that spatial genome organization in most Plasmodium species is constrained by the colocalization of virulence genes. P. falciparum and P. knowlesi, the only two Plasmodium species with gene families involved in antigenic variation, are unique in the effect of these genes on chromosome folding, indicating a potential link between genome organization and gene expression in more virulent pathogens.
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31
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Batugedara G, Le Roch KG. Unraveling the 3D genome of human malaria parasites. Semin Cell Dev Biol 2018; 90:144-153. [PMID: 30009946 DOI: 10.1016/j.semcdb.2018.07.015] [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: 06/19/2018] [Accepted: 07/03/2018] [Indexed: 01/31/2023]
Abstract
The chromosomes within the eukaryotic cell nucleus are highly dynamic and adopt complex hierarchical structures. Understanding how this three-dimensional (3D) nuclear architectureaffects gene regulation, cell cycle progression and disease pathogenesis are important biological questions in development and disease. Recently, many genome-wide technologies including chromosome conformation capture (3C) and 3C-based methodologies (4C, 5C, and Hi-C) have been developed to investigate 3D chromatin structure. In this review, we introduce 3D genome methodologies, with a focus on their application for understanding the nuclear architecture of the human malaria parasite, Plasmodium falciparum. An increasing amount of evidence now suggests that gene regulation in the parasite is largely regulated by epigenetic mechanisms and nuclear reorganization. Here, we explore the 3D genome architecture of P. falciparum, including local and global chromatin structure. In addition, molecular components important for maintaining 3D chromatin organization including architectural proteins and long non-coding RNAs are discussed. Collectively, these studies contribute to our understanding of how the plasticity of 3D genome architecture regulates gene expression and cell cycle progression in this deadly parasite.
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Affiliation(s)
- Gayani Batugedara
- Department of Molecular, Cell and Systems Biology, University of California Riverside, Riverside, CA 92521, USA
| | - Karine G Le Roch
- Department of Molecular, Cell and Systems Biology, University of California Riverside, Riverside, CA 92521, 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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Fastman Y, Assaraf S, Rose M, Milrot E, Basore K, Arasu BS, Desai SA, Elbaum M, Dzikowski R. An upstream open reading frame (uORF) signals for cellular localization of the virulence factor implicated in pregnancy associated malaria. Nucleic Acids Res 2018; 46:4919-4932. [PMID: 29554358 PMCID: PMC6007598 DOI: 10.1093/nar/gky178] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Revised: 02/27/2018] [Accepted: 03/01/2018] [Indexed: 12/17/2022] Open
Abstract
Plasmodium falciparum, the causative agent of the deadliest form of human malaria, alternates expression of variable antigens, encoded by members of a multi-copy gene family named var. In var2csa, the var gene implicated in pregnancy-associated malaria, translational repression is regulated by a unique upstream open reading frame (uORF) found only in its 5' UTR. Here, we report that this translated uORF significantly alters both transcription and posttranslational protein trafficking. The parasite can alter a protein's destination without any modifications to the protein itself, but instead by an element within the 5' UTR of the transcript. This uORF-dependent localization was confirmed by single molecule STORM imaging, followed by fusion of the uORF to a reporter gene which changes its cellular localization from cytoplasmic to ER-associated. These data point towards a novel regulatory role of uORF in protein trafficking, with important implications for the pathology of pregnancy-associated malaria.
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Affiliation(s)
- Yair Fastman
- Department of Microbiology and Molecular Genetics, The Institute for Medical Research Israel - Canada, The Kuvin Center for the Study of Infectious and Tropical Diseases, The Hebrew University-Hadassah Medical School, Jerusalem 91120, Israel
| | - Shany Assaraf
- Department of Microbiology and Molecular Genetics, The Institute for Medical Research Israel - Canada, The Kuvin Center for the Study of Infectious and Tropical Diseases, The Hebrew University-Hadassah Medical School, Jerusalem 91120, Israel
| | - Miriam Rose
- Department of Microbiology and Molecular Genetics, The Institute for Medical Research Israel - Canada, The Kuvin Center for the Study of Infectious and Tropical Diseases, The Hebrew University-Hadassah Medical School, Jerusalem 91120, Israel
| | - Elad Milrot
- Electron Microscopy Unit, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Katherine Basore
- The Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA
| | - B Sivanandam Arasu
- The Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA
| | - Sanjay A Desai
- The Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA
| | - Michael Elbaum
- Department of Materials and Interfaces, Weizmann Institute of Science, Rehovot 76100, 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, The Hebrew University-Hadassah Medical School, Jerusalem 91120, Israel
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34
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Bunnik EM, Cook KB, Varoquaux N, Batugedara G, Prudhomme J, Cort A, Shi L, Andolina C, Ross LS, Brady D, Fidock DA, Nosten F, Tewari R, Sinnis P, Ay F, Vert JP, Noble WS, Le Roch KG. Changes in genome organization of parasite-specific gene families during the Plasmodium transmission stages. Nat Commun 2018; 9:1910. [PMID: 29765020 PMCID: PMC5954139 DOI: 10.1038/s41467-018-04295-5] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Accepted: 04/18/2018] [Indexed: 12/20/2022] Open
Abstract
The development of malaria parasites throughout their various life cycle stages is coordinated by changes in gene expression. We previously showed that the three-dimensional organization of the Plasmodium falciparum genome is strongly associated with gene expression during its replication cycle inside red blood cells. Here, we analyze genome organization in the P. falciparum and P. vivax transmission stages. Major changes occur in the localization and interactions of genes involved in pathogenesis and immune evasion, host cell invasion, sexual differentiation, and master regulation of gene expression. Furthermore, we observe reorganization of subtelomeric heterochromatin around genes involved in host cell remodeling. Depletion of heterochromatin protein 1 (PfHP1) resulted in loss of interactions between virulence genes, confirming that PfHP1 is essential for maintenance of the repressive center. Our results suggest that the three-dimensional genome structure of human malaria parasites is strongly connected with transcriptional activity of specific gene families throughout the life cycle.
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Affiliation(s)
- Evelien M Bunnik
- Department of Microbiology, Immunology & Molecular Genetics, The University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX, 78229, USA
- Department of Molecular, Cell and Systems Biology, University of California Riverside, 900 University Ave, Riverside, CA, 92521, USA
| | - Kate B Cook
- Department of Genome Sciences, University of Washington, 3720 15th Ave NE, Seattle, WA, 98195, USA
| | - Nelle Varoquaux
- Department of Statistics, University of California, 367 Evans Hall, Berkeley, CA, 94720, USA
- Berkeley Institute for Data Science, 190 Doe Library, Berkeley, CA, 94720, USA
- MINES ParisTech, PSL Research University, CBIO-Centre for Computational Biology, 60 boulevard Saint-Michel, 75006, Paris, France
- Institut Curie, 75248, Paris, France
- U900, INSERM, Paris, 75248, France
| | - Gayani Batugedara
- Department of Molecular, Cell and Systems Biology, University of California Riverside, 900 University Ave, Riverside, CA, 92521, USA
| | - Jacques Prudhomme
- Department of Molecular, Cell and Systems Biology, University of California Riverside, 900 University Ave, Riverside, CA, 92521, USA
| | - Anthony Cort
- Department of Molecular, Cell and Systems Biology, University of California Riverside, 900 University Ave, Riverside, CA, 92521, USA
| | - Lirong Shi
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, 615N. Wolfe Street, E5132, Baltimore, MD, 21205, USA
| | - Chiara Andolina
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine Research building, University of Oxford, Old Road campus, Roosevelt Drive, Headington, Oxford, OX3 7FZ, UK
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Tak, 63110, Thailand
| | - Leila S Ross
- Department of Microbiology and Immunology, Columbia University Medical Center, 701W. 168 St., HHSC 1208, New York, NY, 10032, USA
| | - Declan Brady
- School of Life Sciences, Queens Medical Centre, University of Nottingham, Nottingham, NG7 2UH, UK
| | - David A Fidock
- Department of Microbiology and Immunology, Columbia University Medical Center, 701W. 168 St., HHSC 1208, New York, NY, 10032, USA
- Division of Infectious Diseases, Department of Medicine, Columbia University, New York, NY, 10032, USA
| | - Francois Nosten
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine Research building, University of Oxford, Old Road campus, Roosevelt Drive, Headington, Oxford, OX3 7FZ, UK
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Tak, 63110, Thailand
| | - Rita Tewari
- School of Life Sciences, Queens Medical Centre, University of Nottingham, Nottingham, NG7 2UH, UK
| | - Photini Sinnis
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, 615N. Wolfe Street, E5132, Baltimore, MD, 21205, USA
| | - Ferhat Ay
- La Jolla Institute for Allergy & Immunology, 9420 Athena Cir, La Jolla, CA, 92037, USA
| | - Jean-Philippe Vert
- MINES ParisTech, PSL Research University, CBIO-Centre for Computational Biology, 60 boulevard Saint-Michel, 75006, Paris, France
- Institut Curie, 75248, Paris, France
- U900, INSERM, Paris, 75248, France
- Département de mathématiques et applications, École normale supérieure, CNRS, PSL Research University, Paris, 75005, France
| | - William Stafford Noble
- Department of Genome Sciences, University of Washington, 3720 15th Ave NE, Seattle, WA, 98195, USA.
- Department of Computer Science and Engineering, University of Washington, Seattle, WA, 98195, USA.
| | - Karine G Le Roch
- Department of Molecular, Cell and Systems Biology, University of California Riverside, 900 University Ave, Riverside, CA, 92521, USA.
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35
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Liu X, Wang Y, Liang J, Wang L, Qin N, Zhao Y, Zhao G. In-depth comparative analysis of malaria parasite genomes reveals protein-coding genes linked to human disease in Plasmodium falciparum genome. BMC Genomics 2018; 19:312. [PMID: 29716542 PMCID: PMC5930813 DOI: 10.1186/s12864-018-4654-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Accepted: 04/10/2018] [Indexed: 11/10/2022] Open
Abstract
Background Plasmodium falciparum is the most virulent malaria parasite capable of parasitizing human erythrocytes. The identification of genes related to this capability can enhance our understanding of the molecular mechanisms underlying human malaria and lead to the development of new therapeutic strategies for malaria control. With the availability of several malaria parasite genome sequences, performing computational analysis is now a practical strategy to identify genes contributing to this disease. Results Here, we developed and used a virtual genome method to assign 33,314 genes from three human malaria parasites, namely, P. falciparum, P. knowlesi and P. vivax, and three rodent malaria parasites, namely, P. berghei, P. chabaudi and P. yoelii, to 4605 clusters. Each cluster consisted of genes whose protein sequences were significantly similar and was considered as a virtual gene. Comparing the enriched values of all clusters in human malaria parasites with those in rodent malaria parasites revealed 115 P. falciparum genes putatively responsible for parasitizing human erythrocytes. These genes are mainly located in the chromosome internal regions and participate in many biological processes, including membrane protein trafficking and thiamine biosynthesis. Meanwhile, 289 P. berghei genes were included in the rodent parasite-enriched clusters. Most are located in subtelomeric regions and encode erythrocyte surface proteins. Comparing cluster values in P. falciparum with those in P. vivax and P. knowlesi revealed 493 candidate genes linked to virulence. Some of them encode proteins present on the erythrocyte surface and participate in cytoadhesion, virulence factor trafficking, or erythrocyte invasion, but many genes with unknown function were also identified. Cerebral malaria is characterized by accumulation of infected erythrocytes at trophozoite stage in brain microvascular. To discover cerebral malaria-related genes, fast Fourier transformation (FFT) was introduced to extract genes highly transcribed at the trophozoite stage. Finally, 55 candidate genes were identified. Considering that parasite-infected erythrocyte surface protein 2 (PIESP2) contains gap-junction-related Neuromodulin_N domain and that anti-PIESP2 might provide protection against malaria, we chose PIESP2 for further experimental study. Conclusions Our analysis revealed a limited number of genes linked to human disease in P. falciparum genome. These genes could be interesting targets for further functional characterization. Electronic supplementary material The online version of this article (10.1186/s12864-018-4654-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Xuewu Liu
- Department of Pathogenic Biology, Fourth Military Medical University, Xi'an, 710032, China
| | - Yuanyuan Wang
- Department of Neurology, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, China
| | - Jiao Liang
- Department of Pathogenic Biology, Fourth Military Medical University, Xi'an, 710032, China
| | - Luojun Wang
- Department of Neurology, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, China
| | - Na Qin
- Department of Neurology, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, China
| | - Ya Zhao
- Department of Pathogenic Biology, Fourth Military Medical University, Xi'an, 710032, China.
| | - Gang Zhao
- Department of Neurology, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, China.
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36
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Davies HM, Nofal SD, McLaughlin EJ, Osborne AR. Repetitive sequences in malaria parasite proteins. FEMS Microbiol Rev 2018; 41:923-940. [PMID: 29077880 DOI: 10.1093/femsre/fux046] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Accepted: 09/13/2017] [Indexed: 12/13/2022] Open
Abstract
Five species of parasite cause malaria in humans with the most severe disease caused by Plasmodium falciparum. Many of the proteins encoded in the P. falciparum genome are unusually enriched in repetitive low-complexity sequences containing a limited repertoire of amino acids. These repetitive sequences expand and contract dynamically and are among the most rapidly changing sequences in the genome. The simplest repetitive sequences consist of single amino acid repeats such as poly-asparagine tracts that are found in approximately 25% of P. falciparum proteins. More complex repeats of two or more amino acids are also common in diverse parasite protein families. There is no universal explanation for the occurrence of repetitive sequences and it is possible that many confer no function to the encoded protein and no selective advantage or disadvantage to the parasite. However, there are increasing numbers of examples where repetitive sequences are important for parasite protein function. We discuss the diverse roles of low-complexity repetitive sequences throughout the parasite life cycle, from mediating protein-protein interactions to enabling the parasite to evade the host immune system.
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Affiliation(s)
- Heledd M Davies
- The Francis Crick Institute, London, NW1 1AT, United Kingdom
| | - Stephanie D Nofal
- London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, United Kingdom
| | - Emilia J McLaughlin
- Institute of Structural and Molecular Biology, University College London, Gower Street, London WC1E 6BT, United Kingdom
| | - Andrew R Osborne
- Institute of Structural and Molecular Biology, University College London, Gower Street, London WC1E 6BT, United Kingdom.,Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck, Malet Street, London, WC1E 7HX, United Kingdom
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37
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The Plasmodium falciparum transcriptome in severe malaria reveals altered expression of genes involved in important processes including surface antigen-encoding var genes. PLoS Biol 2018; 16:e2004328. [PMID: 29529020 PMCID: PMC5864071 DOI: 10.1371/journal.pbio.2004328] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Revised: 03/22/2018] [Accepted: 02/16/2018] [Indexed: 01/13/2023] Open
Abstract
Within the human host, the malaria parasite Plasmodium falciparum is exposed to multiple selection pressures. The host environment changes dramatically in severe malaria, but the extent to which the parasite responds to-or is selected by-this environment remains unclear. From previous studies, the parasites that cause severe malaria appear to increase expression of a restricted but poorly defined subset of the PfEMP1 variant, surface antigens. PfEMP1s are major targets of protective immunity. Here, we used RNA sequencing (RNAseq) to analyse gene expression in 44 parasite isolates that caused severe and uncomplicated malaria in Papuan patients. The transcriptomes of 19 parasite isolates associated with severe malaria indicated that these parasites had decreased glycolysis without activation of compensatory pathways; altered chromatin structure and probably transcriptional regulation through decreased histone methylation; reduced surface expression of PfEMP1; and down-regulated expression of multiple chaperone proteins. Our RNAseq also identified novel associations between disease severity and PfEMP1 transcripts, domains, and smaller sequence segments and also confirmed all previously reported associations between expressed PfEMP1 sequences and severe disease. These findings will inform efforts to identify vaccine targets for severe malaria and also indicate how parasites adapt to-or are selected by-the host environment in severe malaria.
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38
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Chaudhry SR, Lwin N, Phelan D, Escalante AA, Battistuzzi FU. Comparative analysis of low complexity regions in Plasmodia. Sci Rep 2018; 8:335. [PMID: 29321589 PMCID: PMC5762703 DOI: 10.1038/s41598-017-18695-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Accepted: 12/14/2017] [Indexed: 12/20/2022] Open
Abstract
Low complexity regions (LCRs) are a common feature shared by many genomes, but their evolutionary and functional significance remains mostly unknown. At the core of the uncertainty is a poor understanding of the mechanisms that regulate their retention in genomes, whether driven by natural selection or neutral evolution. Applying a comparative approach of LCRs to multiple strains and species is a powerful approach to identify patterns of conservation in these regions. Using this method, we investigate the evolutionary history of LCRs in the genus Plasmodium based on orthologous protein coding genes shared by 11 species and strains from primate and rodent-infecting pathogens. We find multiple lines of evidence in support of natural selection as a major evolutionary force shaping the composition and conservation of LCRs through time and signatures that their evolutionary paths are species specific. Our findings add a comparative analysis perspective to the debate on the evolution of LCRs and harness the power of sequence comparisons to identify potential functionally important LCR candidates.
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Affiliation(s)
- S R Chaudhry
- Department of Biological Sciences, Oakland University, Rochester, MI, USA.,Center for Molecular Medicine and Genetics, Wayne State University, Detroit, MI, USA
| | - N Lwin
- Department of Biological Sciences, Oakland University, Rochester, MI, USA
| | - D Phelan
- Department of Biological Sciences, Oakland University, Rochester, MI, USA
| | - A A Escalante
- Institute for Genomics and Evolutionary Medicine, Temple University, Philadelphia, PA, USA
| | - F U Battistuzzi
- Department of Biological Sciences, Oakland University, Rochester, MI, USA. .,Center for Data Science and Big Data Analytics, Oakland University, Rochester, MI, USA.
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39
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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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40
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Multifunctional Involvement of a C2H2 Zinc Finger Protein (PbZfp) in Malaria Transmission, Histone Modification, and Susceptibility to DNA Damage Response. mBio 2017; 8:mBio.01298-17. [PMID: 28851851 PMCID: PMC5574716 DOI: 10.1128/mbio.01298-17] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
In sexually reproducing organisms, meiosis is an essential step responsible for generation of haploid gametes from diploid somatic cells. The quest for understanding regulatory mechanisms of meiotic recombination in Plasmodium led to identification of a gene encoding a protein that contains 11 copies of C2H2 zinc fingers (ZnF). Reverse genetic approaches were used to create Plasmodium berghei parasites either lacking expression of full-length Plasmodium berghei zinc finger protein (PbZfp) (knockout [KO]) or expressing PbZfp lacking C-terminal zinc finger region (truncated [Trunc]). Mice infected with KO parasites survived two times longer (P < 0.0001) than mice infected with wild-type (WT) parasites. In mosquito transmission experiments, the infectivity of KO and Trunc parasites was severely compromised (>95% oocyst reduction). KO parasites revealed a total lack of trimethylation of histone 3 at several lysine residues (K4, K27, and K36) without any effect on acetylation patterns (H3K9, H3K14, and H4K16). Reduced DNA damage and reduced expression of topoisomerase-like Spo11 in the KO parasites with normal Rad51 expression further suggest a functional role for PbZfp during genetic recombination that involves DNA double-strand break (DSB) formation followed by DNA repair. These finding raise the possibility of some convergent similarities of PbZfp functions to functions of mammalian PRDM9, also a C2H2 ZnF protein with histone 3 lysine 4 (H3K4) methyltransferase activity. These functions include the major role played by the latter in binding recombination hotspots in the genome during meiosis and trimethylation of the associated histones and subsequent chromatin recruitment of topoisomerase-like Spo11 to catalyze DNA DSB formation and DMC1/Rad51-mediated DNA repair and homologous recombination. Malaria parasites are haploid throughout their life cycle except for a brief time period when zygotes are produced as a result of fertilization between male and female gametes during transmission through the mosquito vector. The reciprocal recombination events that follow zygote formation ensure orderly segregation of homologous chromosomes during meiosis, creating genetic diversity among offspring. Studies presented in the current manuscript identify a novel C2H2 ZnF-containing protein exhibiting multifunctional roles in parasite virulence, mosquito transmission, and homologous recombination during meiosis. Understanding the transmission biology of malaria will result in the identification of novel targets for transmission-blocking intervention approaches.
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41
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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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42
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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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43
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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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44
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Batugedara G, Lu XM, Bunnik EM, Le Roch KG. The Role of Chromatin Structure in Gene Regulation of the Human Malaria Parasite. Trends Parasitol 2017; 33:364-377. [PMID: 28065669 PMCID: PMC5410391 DOI: 10.1016/j.pt.2016.12.004] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Revised: 11/28/2016] [Accepted: 12/07/2016] [Indexed: 12/11/2022]
Abstract
The human malaria parasite, Plasmodium falciparum, depends on a coordinated regulation of gene expression for development and propagation within the human host. Recent developments suggest that gene regulation in the parasite is largely controlled by epigenetic mechanisms. Here, we discuss recent advancements contributing to our understanding of the mechanisms controlling gene regulation in the parasite, including nucleosome landscape, histone modifications, and nuclear architecture. In addition, various processes involved in regulation of parasite-specific genes and gene families are examined. Finally, we address the use of epigenetic processes as targets for novel antimalarial therapies. Collectively, these topics highlight the unique biology of P. falciparum, and contribute to our understanding of mechanisms regulating gene expression in this deadly parasite.
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Affiliation(s)
- Gayani Batugedara
- Department of Cell Biology and Neuroscience, University of California Riverside, Riverside, CA 92521, USA
| | - Xueqing M Lu
- Department of Cell Biology and Neuroscience, University of California Riverside, Riverside, CA 92521, USA
| | - Evelien M Bunnik
- Department of Microbiology, Immunology & Molecular Genetics, The University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | - Karine G Le Roch
- Department of Cell Biology and Neuroscience, University of California Riverside, Riverside, CA 92521, USA.
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45
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Duffy MF, Tang J, Sumardy F, Nguyen HHT, Selvarajah SA, Josling GA, Day KP, Petter M, Brown GV. Activation and clustering of a Plasmodium falciparum var gene are affected by subtelomeric sequences. FEBS J 2016; 284:237-257. [PMID: 27860263 DOI: 10.1111/febs.13967] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Revised: 10/12/2016] [Accepted: 11/15/2016] [Indexed: 11/30/2022]
Abstract
The Plasmodium falciparum var multigene family encodes the cytoadhesive, variant antigen PfEMP1. P. falciparum antigenic variation and cytoadhesion specificity are controlled by epigenetic switching between the single, or few, simultaneously expressed var genes. Most var genes are maintained in perinuclear clusters of heterochromatic telomeres. The active var gene(s) occupy a single, perinuclear var expression site. It is unresolved whether the var expression site forms in situ at a telomeric cluster or whether it is an extant compartment to which single chromosomes travel, thus controlling var switching. Here we show that transcription of a var gene did not require decreased colocalisation with clusters of telomeres, supporting var expression site formation in situ. However following recombination within adjacent subtelomeric sequences, the same var gene was persistently activated and did colocalise less with telomeric clusters. Thus, participation in stable, heterochromatic, telomere clusters and var switching are independent but are both affected by subtelomeric sequences. The var expression site colocalised with the euchromatic mark H3K27ac to a greater extent than it did with heterochromatic H3K9me3. H3K27ac was enriched within the active var gene promoter even when the var gene was transiently repressed in mature parasites and thus H3K27ac may contribute to var gene epigenetic memory.
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Affiliation(s)
- Michael F Duffy
- Department of Medicine, Royal Melbourne Hospital, The University of Melbourne at The Peter Doherty Institute for Infection and Immunity, Victoria, Australia.,The School of BioSciences, Bio21, The University of Melbourne, Victoria, Australia
| | - Jingyi Tang
- Department of Medicine, Royal Melbourne Hospital, The University of Melbourne at The Peter Doherty Institute for Infection and Immunity, Victoria, Australia.,The School of BioSciences, Bio21, The University of Melbourne, Victoria, Australia
| | - Fransisca Sumardy
- Department of Medicine, Royal Melbourne Hospital, The University of Melbourne at The Peter Doherty Institute for Infection and Immunity, Victoria, Australia.,The Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia
| | - Hanh H T Nguyen
- Department of Medicine, Royal Melbourne Hospital, The University of Melbourne at The Peter Doherty Institute for Infection and Immunity, Victoria, Australia.,The School of BioSciences, Bio21, The University of Melbourne, Victoria, Australia
| | - Shamista A Selvarajah
- Department of Medicine, Royal Melbourne Hospital, The University of Melbourne at The Peter Doherty Institute for Infection and Immunity, Victoria, Australia.,The School of BioSciences, Bio21, The University of Melbourne, Victoria, Australia
| | - Gabrielle A Josling
- Department of Medicine, Royal Melbourne Hospital, The University of Melbourne at The Peter Doherty Institute for Infection and Immunity, Victoria, Australia.,Department of Biochemistry and Molecular Biology, The Pennsylvania State University, State College, PA, USA
| | - Karen P Day
- The School of BioSciences, Bio21, The University of Melbourne, Victoria, Australia
| | - Michaela Petter
- Department of Medicine, Royal Melbourne Hospital, The University of Melbourne at The Peter Doherty Institute for Infection and Immunity, Victoria, Australia.,The School of BioSciences, Bio21, The University of Melbourne, Victoria, Australia
| | - Graham V Brown
- The Nossal Institute for Global Health, The University of Melbourne, Victoria, Australia
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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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47
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Recombination and Diversification of the Variant Antigen Encoding Genes in the Malaria Parasite Plasmodium falciparum. Microbiol Spectr 2016; 2. [PMID: 26104446 DOI: 10.1128/microbiolspec.mdna3-0022-2014] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The most severe form of human malaria is caused by the protozoan parasite Plasmodium falciparum. These parasites invade and replicate within the circulating red blood cells of infected individuals leading to numerous disease manifestations, including severe anemia, altered circulation, and tissue inflammation. Malaria parasites are also known for their ability to maintain a chronic infection through antigenic variation, the ability to systematically alter the antigens displayed on the surface of infected cells and thereby avoid clearance by the host's antibody response. The genome of P. falciparum includes several large, multicopy gene families that encode highly variable forms of the surface proteins that are the targets of host immunity. Alterations in expression of genes within these families are responsible for antigenic variation. This process requires the continuous generation of new antigenic variants within these gene families, and studies have shown that new variants arise through extensive recombination and gene conversion events between family members. Malaria parasites possess an unusual complement of DNA repair pathways, thus the study of recombination between variant antigen encoding genes provides a unique view into the evolution of mobile DNA in an organism distantly related to the more closely studied model eukaryotes.
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48
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Karmodiya K, Pradhan SJ, Joshi B, Jangid R, Reddy PC, Galande S. A comprehensive epigenome map of Plasmodium falciparum reveals unique mechanisms of transcriptional regulation and identifies H3K36me2 as a global mark of gene suppression. Epigenetics Chromatin 2015; 8:32. [PMID: 26388940 PMCID: PMC4574195 DOI: 10.1186/s13072-015-0029-1] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Accepted: 09/08/2015] [Indexed: 12/14/2022] Open
Abstract
Background Role of epigenetic mechanisms towards regulation of the complex life cycle/pathogenesis of Plasmodium falciparum, the causative agent of malaria, has been poorly understood. To elucidate stage-specific epigenetic regulation, we performed genome-wide mapping of multiple histone modifications of P. falciparum. Further to understand the differences in transcription regulation in P. falciparum and its host, human, we compared their histone modification profiles. Results Our comprehensive comparative analysis suggests distinct mode of transcriptional regulation in malaria parasite by virtue of poised genes and differential histone modifications. Furthermore, analysis of histone modification profiles predicted 562 genes producing anti-sense RNAs and 335 genes having bidirectional promoter activity, which raises the intriguing possibility of RNA-mediated regulation of transcription in P. falciparum. Interestingly, we found that H3K36me2 acts as a global repressive mark and gene regulation is fine tuned by the ratio of activation marks to H3K36me2 in P. falciparum. This novel mechanism of gene regulation is supported by the fact that knockout of SET genes (responsible for H3K36 methylation) leads to up-regulation of genes with highest occupancy of H3K36me2 in wild-type P. falciparum. Moreover, virulence (var) genes are mostly poised and marked by a unique set of activation (H4ac) and repression (H3K9me3) marks, which are mutually exclusive to other Plasmodium housekeeping genes. Conclusions Our study reveals unique plasticity in the epigenetic regulation in P. falciparum which can influence parasite virulence and pathogenicity. The observed differences in the histone code and transcriptional regulation in P. falciparum and its host will open new avenues for epigenetic drug development against malaria parasite. Electronic supplementary material The online version of this article (doi:10.1186/s13072-015-0029-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Krishanpal Karmodiya
- Department of Biology, Indian Institute of Science Education and Research, Pune, Maharashtra India
| | - Saurabh J Pradhan
- Department of Biology, Indian Institute of Science Education and Research, Pune, Maharashtra India
| | - Bhagyashree Joshi
- Department of Biology, Indian Institute of Science Education and Research, Pune, Maharashtra India
| | - Rahul Jangid
- Department of Biology, Indian Institute of Science Education and Research, Pune, Maharashtra India
| | - Puli Chandramouli Reddy
- Department of Biology, Indian Institute of Science Education and Research, Pune, Maharashtra India
| | - Sanjeev Galande
- Department of Biology, Indian Institute of Science Education and Research, Pune, Maharashtra India.,Centre of Excellence in Epigenetics, Indian Institute of Science Education and Research, Pune, India.,National Centre for Cell Science, Pune, India
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49
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Wei G, Zhao Y, Zhang Q, Pan W. Dual regulatory effects of non-coding GC-rich elements on the expression of virulence genes in malaria parasites. INFECTION GENETICS AND EVOLUTION 2015; 36:490-499. [PMID: 26299885 DOI: 10.1016/j.meegid.2015.08.023] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Revised: 08/12/2015] [Accepted: 08/18/2015] [Indexed: 01/19/2023]
Abstract
As the primary virulence factor of falciparum malaria, var genes harboring mutually exclusive expression pattern lead to antigenic variation and immune evasion of this pathogen in human host. Although various mechanisms contribute to silence of var genes, little is known of transcriptional activation pathways of a single var gene and maintenance of its active state with other silent var loci. Here, we report a monoallelic expression pattern of the non-coding GC-elements flanking chromosomal internal var genes, and transcript from the active one was required for activation of the var gene in the same array. Meanwhile, GFP reporter assays revealed a repressive effect on the adjacent gene induced by DNA motifs of the insulator-like GC-element, which was linked to heterochromatin subnuclear localization. Taken together, these data for the first time provide experimental evidence of the dual cis- and trans-acting regulatory functions of the GC-elements in both silence and activation of var genes, which would advance our understanding of the complex regulatory network of the virulence gene family in P. falciparum.
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Affiliation(s)
- Guiying Wei
- Institute for Infectious Diseases and Vaccine Development, Tongji University School of Medicine, 1239 Siping Road, Shanghai 200092, China
| | - Yuemeng Zhao
- Institute for Infectious Diseases and Vaccine Development, Tongji University School of Medicine, 1239 Siping Road, Shanghai 200092, China
| | - Qingfeng Zhang
- Institute for Infectious Diseases and Vaccine Development, Tongji University School of Medicine, 1239 Siping Road, Shanghai 200092, China.
| | - Weiqing Pan
- Institute for Infectious Diseases and Vaccine Development, Tongji University School of Medicine, 1239 Siping Road, Shanghai 200092, China; Department of Tropical Infectious Diseases, Second Military Medical University, 800 Xiang Yin Road, Shanghai 200433, China.
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50
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Ukaegbu UE, Deitsch KW. The Emerging Role for RNA Polymerase II in Regulating Virulence Gene Expression in Malaria Parasites. PLoS Pathog 2015; 11:e1004926. [PMID: 26181323 PMCID: PMC4504705 DOI: 10.1371/journal.ppat.1004926] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Affiliation(s)
- Uchechi E. Ukaegbu
- Department of Microbiology and Immunology, Weill Medical College of Cornell University, New York, New York, United States of America
| | - Kirk W. Deitsch
- Department of Microbiology and Immunology, Weill Medical College of Cornell University, New York, New York, United States of America
- * E-mail:
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