1
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Liu S, Ebel ER, Luniewski A, Zulawinska J, Simpson ML, Kim J, Ene N, Braukmann TWA, Congdon M, Santos W, Yeh E, Guler JL. Direct long read visualization reveals metabolic interplay between two antimalarial drug targets. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.13.528367. [PMID: 36824743 PMCID: PMC9948948 DOI: 10.1101/2023.02.13.528367] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
Increases in the copy number of large genomic regions, termed genome amplification, are an important adaptive strategy for malaria parasites. Numerous amplifications across the Plasmodium falciparum genome contribute directly to drug resistance or impact the fitness of this protozoan parasite. During the characterization of parasite lines with amplifications of the dihydroorotate dehydrogenase (DHODH) gene, we detected increased copies of an additional genomic region that encompassed 3 genes (~5 kb) including GTP cyclohydrolase I (GCH1 amplicon). While this gene is reported to increase the fitness of antifolate resistant parasites, GCH1 amplicons had not previously been implicated in any other antimalarial resistance context. Here, we further explored the association between GCH1 and DHODH copy number. Using long read sequencing and single read visualization, we directly observed a higher number of tandem GCH1 amplicons in parasites with increased DHODH copies (up to 9 amplicons) compared to parental parasites (3 amplicons). While all GCH1 amplicons shared a consistent structure, expansions arose in 2-unit steps (from 3 to 5 to 7, etc copies). Adaptive evolution of DHODH and GCH1 loci was further bolstered when we evaluated prior selection experiments; DHODH amplification was only successful in parasite lines with pre-existing GCH1 amplicons. These observations, combined with the direct connection between metabolic pathways that contain these enzymes, lead us to propose that the GCH1 locus is beneficial for the fitness of parasites exposed to DHODH inhibitors. This finding highlights the importance of studying variation within individual parasite genomes as well as biochemical connections of drug targets as novel antimalarials move towards clinical approval.
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Affiliation(s)
- Shiwei Liu
- University of Virginia, Department of Biology, Charlottesville, VA, USA
- Current affiliation: Indiana University School of Medicine, Indianapolis, IN, USA
| | - Emily R. Ebel
- Stanford, Departments of Pediatrics and Microbiology & Immunology, Stanford, CA, USA
| | | | - Julia Zulawinska
- University of Virginia, Department of Biology, Charlottesville, VA, USA
| | | | - Jane Kim
- University of Virginia, Department of Biology, Charlottesville, VA, USA
| | - Nnenna Ene
- University of Virginia, Department of Biology, Charlottesville, VA, USA
| | | | - Molly Congdon
- Virginia Tech, Department of Chemistry, Blacksburg, VA, USA
| | - Webster Santos
- Virginia Tech, Department of Chemistry, Blacksburg, VA, USA
| | - Ellen Yeh
- Stanford University, Departments of Pathology and Microbiology & Immunology, Stanford, CA, USA
| | - Jennifer L. Guler
- University of Virginia, Department of Biology, Charlottesville, VA, USA
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2
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Babai R, Izrael R, Vértessy BG. Characterization of the dynamics of Plasmodium falciparum deoxynucleotide-triphosphate pool in a stage-specific manner. Sci Rep 2022; 12:19926. [PMID: 36402851 PMCID: PMC9675800 DOI: 10.1038/s41598-022-23807-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Accepted: 11/06/2022] [Indexed: 11/21/2022] Open
Abstract
Understanding and characterizing the molecular background of the maintenance of genomic integrity might be a major factor in comprehending the exceptional ability of the malaria parasite, Plasmodium falciparum to adapt at a fast pace to antimalarials. A balanced nucleotide pool is an essential factor for high-fidelity replication. The lack of detailed studies on deoxynucleotide-triphosphate (dNTP) pools in various intraerythrocytic stages of Plasmodium falciparum motivated our present study. Here, we focused on the building blocks of DNA and utilized an EvaGreen-based dNTP incorporation assay to successfully measure the temporal dynamics of dNTPs in every intraerythrocytic stage and in drug-treated trophozoites. Our findings show that the ratio of dNTPs in the ring-stage parasites significantly differs from the more mature trophozoite and schizont stages. We were also able to detect dGTP levels that have never been shown before and found it to be the least abundant dNTP in all stages. Treatment with WR99210, a TS-DHFR inhibitor drug, affected not only dTTP, but also dGTP levels, despite its presumed selective action on pyrimidine biosynthesis. Results from our studies might assist in a better understanding of genome integrity mechanisms and may potentially lead to novel drug related aspects involving purine and pyrimidine metabolic targets.
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Affiliation(s)
- Réka Babai
- grid.425578.90000 0004 0512 3755Malaria Research Laboratory, Institute of Enzymology, Research Centre for Natural Sciences, Budapest, 1117 Hungary ,grid.6759.d0000 0001 2180 0451George A. Olah Doctoral School of Chemistry and Chemical Technology, BME Budapest University of Technology and Economics, Budapest, 1111 Hungary ,grid.6759.d0000 0001 2180 0451Department of Applied Biotechnology and Food Sciences, BME Budapest University of Technology and Economics, Budapest, 1111 Hungary
| | - Richard Izrael
- grid.425578.90000 0004 0512 3755Malaria Research Laboratory, Institute of Enzymology, Research Centre for Natural Sciences, Budapest, 1117 Hungary ,grid.9008.10000 0001 1016 9625Doctoral School of Multidisciplinary Medical Sciences, University of Szeged, Szeged, 6720 Hungary
| | - Beáta G. Vértessy
- grid.425578.90000 0004 0512 3755Malaria Research Laboratory, Institute of Enzymology, Research Centre for Natural Sciences, Budapest, 1117 Hungary ,grid.6759.d0000 0001 2180 0451Department of Applied Biotechnology and Food Sciences, BME Budapest University of Technology and Economics, Budapest, 1111 Hungary
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3
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Kołomański M, Szyda J, Frąszczak M, Mielczarek M. DNA sequence features underlying large-scale duplications and deletions in human. J Appl Genet 2022; 63:527-533. [PMID: 35590085 PMCID: PMC9365719 DOI: 10.1007/s13353-022-00704-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Revised: 03/22/2022] [Accepted: 05/05/2022] [Indexed: 11/25/2022]
Abstract
Copy number variants (CNVs) may cover up to 12% of the whole genome and have substantial impact on phenotypes. We used 5867 duplications and 33,181 deletions available from the 1000 Genomes Project to characterise genomic regions vulnerable to CNV formation and to identify sequence features characteristic for those regions. The GC content for deletions was lower and for duplications was higher than for randomly selected regions. In regions flanking deletions and downstream of duplications, content was higher than in the random sequences, but upstream of duplication content was lower. In duplications and downstream of deletion regions, the percentage of low-complexity sequences was not different from the randomised data. In deletions and upstream of CNVs, it was higher, while for downstream of duplications, it was lower as compared to random sequences. The majority of CNVs intersected with genic regions — mainly with introns. GC content may be associated with CNV formation and CNVs, especially duplications are initiated in low-complexity regions. Moreover, CNVs located or overlapped with introns indicate their role in shaping intron variability. Genic CNV regions were enriched in many essential biological processes such as cell adhesion, synaptic transmission, transport, cytoskeleton organization, immune response and metabolic mechanisms, which indicates that these large-scaled variants play important biological roles.
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Affiliation(s)
- Mateusz Kołomański
- Biostatistics Group, Department of Genetics, Wroclaw University of Environmental and Life Sciences, Wroclaw, Poland
| | - Joanna Szyda
- Biostatistics Group, Department of Genetics, Wroclaw University of Environmental and Life Sciences, Wroclaw, Poland
| | - Magdalena Frąszczak
- Biostatistics Group, Department of Genetics, Wroclaw University of Environmental and Life Sciences, Wroclaw, Poland
| | - Magda Mielczarek
- Biostatistics Group, Department of Genetics, Wroclaw University of Environmental and Life Sciences, Wroclaw, Poland.
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4
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Akoniyon OP, Adewumi TS, Maharaj L, Oyegoke OO, Roux A, Adeleke MA, Maharaj R, Okpeku M. Whole Genome Sequencing Contributions and Challenges in Disease Reduction Focused on Malaria. BIOLOGY 2022; 11:587. [PMID: 35453786 PMCID: PMC9027812 DOI: 10.3390/biology11040587] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/13/2022] [Revised: 03/31/2022] [Accepted: 04/01/2022] [Indexed: 12/11/2022]
Abstract
Malaria elimination remains an important goal that requires the adoption of sophisticated science and management strategies in the era of the COVID-19 pandemic. The advent of next generation sequencing (NGS) is making whole genome sequencing (WGS) a standard today in the field of life sciences, as PCR genotyping and targeted sequencing provide insufficient information compared to the whole genome. Thus, adapting WGS approaches to malaria parasites is pertinent to studying the epidemiology of the disease, as different regions are at different phases in their malaria elimination agenda. Therefore, this review highlights the applications of WGS in disease management, challenges of WGS in controlling malaria parasites, and in furtherance, provides the roles of WGS in pursuit of malaria reduction and elimination. WGS has invaluable impacts in malaria research and has helped countries to reach elimination phase rapidly by providing required information needed to thwart transmission, pathology, and drug resistance. However, to eliminate malaria in sub-Saharan Africa (SSA), with high malaria transmission, we recommend that WGS machines should be readily available and affordable in the region.
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Affiliation(s)
- Olusegun Philip Akoniyon
- Discipline of Genetics, School of Life Sciences, University of KwaZulu-Natal, Westville Campus, Durban 4041, South Africa; (O.P.A.); (T.S.A.); (L.M.); (O.O.O.); (A.R.); (M.A.A.)
| | - Taiye Samson Adewumi
- Discipline of Genetics, School of Life Sciences, University of KwaZulu-Natal, Westville Campus, Durban 4041, South Africa; (O.P.A.); (T.S.A.); (L.M.); (O.O.O.); (A.R.); (M.A.A.)
| | - Leah Maharaj
- Discipline of Genetics, School of Life Sciences, University of KwaZulu-Natal, Westville Campus, Durban 4041, South Africa; (O.P.A.); (T.S.A.); (L.M.); (O.O.O.); (A.R.); (M.A.A.)
| | - Olukunle Olugbenle Oyegoke
- Discipline of Genetics, School of Life Sciences, University of KwaZulu-Natal, Westville Campus, Durban 4041, South Africa; (O.P.A.); (T.S.A.); (L.M.); (O.O.O.); (A.R.); (M.A.A.)
| | - Alexandra Roux
- Discipline of Genetics, School of Life Sciences, University of KwaZulu-Natal, Westville Campus, Durban 4041, South Africa; (O.P.A.); (T.S.A.); (L.M.); (O.O.O.); (A.R.); (M.A.A.)
| | - Matthew A. Adeleke
- Discipline of Genetics, School of Life Sciences, University of KwaZulu-Natal, Westville Campus, Durban 4041, South Africa; (O.P.A.); (T.S.A.); (L.M.); (O.O.O.); (A.R.); (M.A.A.)
| | - Rajendra Maharaj
- Office of Malaria Research, South African Medical Research Council, Cape Town 7505, South Africa;
| | - Moses Okpeku
- Discipline of Genetics, School of Life Sciences, University of KwaZulu-Natal, Westville Campus, Durban 4041, South Africa; (O.P.A.); (T.S.A.); (L.M.); (O.O.O.); (A.R.); (M.A.A.)
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5
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Liu S, Huckaby AC, Brown AC, Moore CC, Burbulis I, McConnell MJ, Güler JL. Single-cell sequencing of the small and AT-skewed genome of malaria parasites. Genome Med 2021; 13:75. [PMID: 33947449 PMCID: PMC8094492 DOI: 10.1186/s13073-021-00889-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Accepted: 04/17/2021] [Indexed: 12/23/2022] Open
Abstract
Single-cell genomics is a rapidly advancing field; however, most techniques are designed for mammalian cells. We present a single-cell sequencing pipeline for an intracellular parasite, Plasmodium falciparum, with a small genome of extreme base content. Through optimization of a quasi-linear amplification method, we target the parasite genome over contaminants and generate coverage levels allowing detection of minor genetic variants. This work, as well as efforts that build on these findings, will enable detection of parasite heterogeneity contributing to P. falciparum adaptation. Furthermore, this study provides a framework for optimizing single-cell amplification and variant analysis in challenging genomes.
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Affiliation(s)
- Shiwei Liu
- Department of Biology, University of Virginia, Charlottesville, VA, USA
| | - Adam C Huckaby
- Department of Biology, University of Virginia, Charlottesville, VA, USA
| | - Audrey C Brown
- Department of Biology, University of Virginia, Charlottesville, VA, USA
| | - Christopher C Moore
- Division of Infectious Diseases and International Health, University of Virginia, Charlottesville, VA, USA
| | - Ian Burbulis
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA, USA
- Escuela de Medicina, Universidad San Sebastian, Puerto Montt, Chile
| | - Michael J McConnell
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA, USA
- Department of Neuroscience, University of Virginia School of Medicine, Charlottesville, VA, USA
- Current address: Lieber Institute for Brain Development, Baltimore, MD, USA
| | - Jennifer L Güler
- Department of Biology, University of Virginia, Charlottesville, VA, USA.
- Division of Infectious Diseases and International Health, University of Virginia, Charlottesville, VA, USA.
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6
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McDaniels JM, Huckaby AC, Carter SA, Lingeman S, Francis A, Congdon M, Santos W, Rathod PK, Guler JL. Extrachromosomal DNA amplicons in antimalarial-resistant Plasmodium falciparum. Mol Microbiol 2021; 115:574-590. [PMID: 33053232 PMCID: PMC8246734 DOI: 10.1111/mmi.14624] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 10/02/2020] [Accepted: 10/08/2020] [Indexed: 12/29/2022]
Abstract
Extrachromosomal (ec) DNAs are genetic elements that exist separately from the genome. Since ecDNA can carry beneficial genes, they are a powerful adaptive mechanism in cancers and many pathogens. For the first time, we report ecDNA contributing to antimalarial resistance in Plasmodium falciparum, the most virulent human malaria parasite. Using pulse field gel electrophoresis combined with PCR-based copy number analysis, we detected two ecDNA elements that differ in migration and structure. Entrapment in the electrophoresis well and low susceptibility to exonucleases revealed that the biologically relevant ecDNA element is large and complex in structure. Using deep sequencing, we show that ecDNA originates from the chromosome and expansion of an ecDNA-specific sequence may improve its segregation or expression. We speculate that ecDNA is maintained using established mechanisms due to shared characteristics with the mitochondrial genome. Implications of ecDNA discovery in this organism are wide-reaching due to the potential for new strategies to target resistance development.
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Affiliation(s)
| | - Adam C. Huckaby
- Department of BiologyUniversity of VirginiaCharlottesvilleVAUSA
| | | | | | - Audrey Francis
- Department of BiologyUniversity of VirginiaCharlottesvilleVAUSA
| | | | | | | | - Jennifer L. Guler
- Department of BiologyUniversity of VirginiaCharlottesvilleVAUSA
- Division of Infectious Diseases and International HealthDepartment of MedicineUniversity of VirginiaCharlottesvilleVAUSA
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7
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Wang W, Peng D, Baptista RP, Li Y, Kissinger JC, Tarleton RL. Strain-specific genome evolution in Trypanosoma cruzi, the agent of Chagas disease. PLoS Pathog 2021; 17:e1009254. [PMID: 33508020 PMCID: PMC7872254 DOI: 10.1371/journal.ppat.1009254] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 02/09/2021] [Accepted: 12/22/2020] [Indexed: 12/16/2022] Open
Abstract
The protozoan Trypanosoma cruzi almost invariably establishes life-long infections in humans and other mammals, despite the development of potent host immune responses that constrain parasite numbers. The consistent, decades-long persistence of T. cruzi in human hosts arises at least in part from the remarkable level of genetic diversity in multiple families of genes encoding the primary target antigens of anti-parasite immune responses. However, the highly repetitive nature of the genome-largely a result of these same extensive families of genes-have prevented a full understanding of the extent of gene diversity and its maintenance in T. cruzi. In this study, we have combined long-read sequencing and proximity ligation mapping to generate very high-quality assemblies of two T. cruzi strains representing the apparent ancestral lineages of the species. These assemblies reveal not only the full repertoire of the members of large gene families in the two strains, demonstrating extreme diversity within and between isolates, but also provide evidence of the processes that generate and maintain that diversity, including extensive gene amplification, dispersion of copies throughout the genome and diversification via recombination and in situ mutations. Gene amplification events also yield significant copy number variations in a substantial number of genes presumably not required for or involved in immune evasion, thus forming a second level of strain-dependent variation in this species. The extreme genome flexibility evident in T. cruzi also appears to create unique challenges with respect to preserving core genome functions and gene expression that sets this species apart from related kinetoplastids.
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Affiliation(s)
- Wei Wang
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia, United States of America
| | - Duo Peng
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia, United States of America
- Department of Cellular Biology, University of Georgia, Athens, Georgia, United States of America
| | - Rodrigo P. Baptista
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia, United States of America
- Institute of Bioinformatics, University of Georgia, Athens, Georgia, United States of America
| | - Yiran Li
- Institute of Bioinformatics, University of Georgia, Athens, Georgia, United States of America
| | - Jessica C. Kissinger
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia, United States of America
- Institute of Bioinformatics, University of Georgia, Athens, Georgia, United States of America
- Department of Genetics, University of Georgia, Athens, Georgia, United States of America
| | - Rick L. Tarleton
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia, United States of America
- Department of Cellular Biology, University of Georgia, Athens, Georgia, United States of America
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8
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Turkiewicz A, Manko E, Sutherland CJ, Diez Benavente E, Campino S, Clark TG. Genetic diversity of the Plasmodium falciparum GTP-cyclohydrolase 1, dihydrofolate reductase and dihydropteroate synthetase genes reveals new insights into sulfadoxine-pyrimethamine antimalarial drug resistance. PLoS Genet 2020; 16:e1009268. [PMID: 33382691 PMCID: PMC7774857 DOI: 10.1371/journal.pgen.1009268] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2020] [Accepted: 11/10/2020] [Indexed: 12/13/2022] Open
Abstract
Plasmodium falciparum parasites resistant to antimalarial treatments have hindered malaria disease control. Sulfadoxine-pyrimethamine (SP) was used globally as a first-line treatment for malaria after wide-spread resistance to chloroquine emerged and, although replaced by artemisinin combinations, is currently used as intermittent preventive treatment of malaria in pregnancy and in young children as part of seasonal malaria chemoprophylaxis in sub-Saharan Africa. The emergence of SP-resistant parasites has been predominantly driven by cumulative build-up of mutations in the dihydrofolate reductase (pfdhfr) and dihydropteroate synthetase (pfdhps) genes, but additional amplifications in the folate pathway rate-limiting pfgch1 gene and promoter, have recently been described. However, the genetic make-up and prevalence of those amplifications is not fully understood. We analyse the whole genome sequence data of 4,134 P. falciparum isolates across 29 malaria endemic countries, and reveal that the pfgch1 gene and promoter amplifications have at least ten different forms, occurring collectively in 23% and 34% in Southeast Asian and African isolates, respectively. Amplifications are more likely to be present in isolates with a greater accumulation of pfdhfr and pfdhps substitutions (median of 1 additional mutations; P<0.00001), and there was evidence that the frequency of pfgch1 variants may be increasing in some African populations, presumably under the pressure of SP for chemoprophylaxis and anti-folate containing antibiotics used for the treatment of bacterial infections. The selection of P. falciparum with pfgch1 amplifications may enhance the fitness of parasites with pfdhfr and pfdhps substitutions, potentially threatening the efficacy of this regimen for prevention of malaria in vulnerable groups. Our work describes new pfgch1 amplifications that can be used to inform the surveillance of SP drug resistance, its prophylactic use, and future experimental work to understand functional mechanisms.
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Affiliation(s)
- Anna Turkiewicz
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Emilia Manko
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Colin J. Sutherland
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Ernest Diez Benavente
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Susana Campino
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Taane G. Clark
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, United Kingdom
- Department of Infectious Disease Epidemiology, Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, United Kingdom
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9
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Zhang X, Deitsch KW, Kirkman LA. The contribution of extrachromosomal DNA to genome plasticity in malaria parasites. Mol Microbiol 2020; 115:503-507. [PMID: 33103309 DOI: 10.1111/mmi.14632] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Revised: 10/19/2020] [Accepted: 10/19/2020] [Indexed: 01/20/2023]
Abstract
Malaria caused by the protozoan parasite Plasmodium falciparum continues to impose significant morbidity and mortality, despite substantial investment into drug and vaccine development and deployment. Underlying the resilience of this parasite is its remarkable ability to undergo genome modifications, thus, providing parasite populations with extensive genetic variability that accelerates selection of drug resistance and limits the efficacy of most vaccines. This genome plasticity is rooted in the mechanisms of DNA repair that parasites employ to maintain genome integrity, a process skewed toward homologous recombination through the evolutionary loss of classical nonhomologous end joining. Repair of DNA double-strand breaks have been shown to enable "shuffling" of antigen-encoding gene sequences to vastly increase antigen diversity and to enable copy number expansion of genes that contribute to drug resistance. The latter phenomenon has been proposed to be a major contributor to the rise of resistance to several classes of antimalarial drugs. In this issue of Molecular Microbiology, McDaniels and colleagues add yet another mechanism that malaria parasites use to reduce drug susceptibility by demonstrating that P. falciparum can maintain expanded arrays of drug resistance cassettes as stably replicating, circular, extrachromosomal DNAs, thus, expanding genome plasticity beyond the parasite's 14 nuclear chromosomes.
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Affiliation(s)
- Xu Zhang
- 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
| | - 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
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10
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Brashear AM, Huckaby AC, Fan Q, Dillard LJ, Hu Y, Li Y, Zhao Y, Wang Z, Cao Y, Miao J, Guler JL, Cui L. New Plasmodium vivax Genomes From the China-Myanmar Border. Front Microbiol 2020; 11:1930. [PMID: 32849480 PMCID: PMC7432439 DOI: 10.3389/fmicb.2020.01930] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Accepted: 07/22/2020] [Indexed: 11/13/2022] Open
Abstract
Plasmodium vivax is increasingly the dominant species of malaria in the Greater Mekong Subregion (GMS), which is pursuing regional malaria elimination. P. vivax lineages in the GMS are poorly characterized. Currently, P. vivax reference genomes are scarce due to difficulties in culturing the parasite and lack of high-quality samples. In addition, P. vivax is incredibly diverse, necessitating the procurement of reference genomes from different geographical regions. Here we present four new P. vivax draft genomes assembled de novo from clinical samples collected in the China-Myanmar border area. We demonstrate comparable length and content to existing genomes, with the majority of structural variation occurring around subtelomeric regions and exported proteins, which we corroborated with detection of copy number variations in these regions. We predicted peptides from all PIR gene subfamilies, except for PIR D. We confirmed that proteins classically labeled as PIR D family members are not identifiable by PIR motifs, and actually bear stronger resemblance to DUF (domain of unknown function) family DUF3671, potentially pointing to a new, closely related gene family. Further, phylogenetic analyses of MSP7 genes showed high variability within the MSP7-B family compared to MSP7-A and -C families, and the result was comparable to that from whole genome analyses. The new genome assemblies serve as a resource for studying P. vivax within the GMS.
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Affiliation(s)
- Awtum M. Brashear
- Department of Internal Medicine, University of South Florida, Tampa, Tampa, FL, United States
| | - Adam C. Huckaby
- Department of Biology, University of Virginia, Charlottesville, VA, United States
| | - Qi Fan
- Dalian Institute of Science and Technology, Dalian, China
| | - Luke J. Dillard
- Department of Biology, University of Virginia, Charlottesville, VA, United States
| | - Yubing Hu
- Department of Immunology, College of Basic Medical Science, China Medical University, Shenyang, China
| | - Yuling Li
- Department of Immunology, College of Basic Medical Science, China Medical University, Shenyang, China
| | - Yan Zhao
- Department of Immunology, College of Basic Medical Science, China Medical University, Shenyang, China
| | - Zenglei Wang
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Yaming Cao
- Department of Immunology, College of Basic Medical Science, China Medical University, Shenyang, China
| | - Jun Miao
- Department of Internal Medicine, University of South Florida, Tampa, Tampa, FL, United States
| | - Jennifer L. Guler
- Department of Biology, University of Virginia, Charlottesville, VA, United States
| | - Liwang Cui
- Department of Internal Medicine, University of South Florida, Tampa, Tampa, FL, United States
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11
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Exploration of copy number variation in genes related to anti-malarial drug resistance in Plasmodium falciparum. Gene 2020; 736:144414. [PMID: 32006594 DOI: 10.1016/j.gene.2020.144414] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 01/27/2020] [Accepted: 01/28/2020] [Indexed: 12/16/2022]
Abstract
Development of drug resistance in P. falciparum is one of the major problems associated with malaria treatment. Parasite genetic factors such as single nucleotide polymorphisms (SNPs) and copy number variations (CNV) have shown their role in drug resistance. Most of the studies have focused on the role of SNPs and drug resistance in parasite. However, it has also been shown that CNV is associated with adaptation and drug resistance in parasite. Hence, exploration of copy number polymorphism in essential genes of P. falciparum and their role in anti-malarial resistance is important. This review provides the recent information related to genetic profile of CNV marker in plasmepsin and other genes associated with drugresistanceinP. falciparum. It may be suggested that CNVs in plasmepsin genes are the major driver of piperaquine resistance. Moreover, CNVs in pfcrt and pfmdr1genes appear to play important role in adaptation and hence survival of the parasite. It may be hypothesized that targeting of CNV formation in the parasite could be beneficial for breakdown of its adaption in response to drug pressure.
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Erath J, Djuranovic S, Djuranovic SP. Adaptation of Translational Machinery in Malaria Parasites to Accommodate Translation of Poly-Adenosine Stretches Throughout Its Life Cycle. Front Microbiol 2019; 10:2823. [PMID: 31866984 PMCID: PMC6908487 DOI: 10.3389/fmicb.2019.02823] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Accepted: 11/21/2019] [Indexed: 11/13/2022] Open
Abstract
Malaria is caused by unicellular apicomplexan parasites of the genus Plasmodium, which includes the major human parasite Plasmodium falciparum. The complex cycle of the malaria parasite in both mosquito and human hosts has been studied extensively. There is tight control of gene expression in each developmental stage, and at every level of gene synthesis: from RNA transcription, to its subsequent translation, and finally post-translational modifications of the resulting protein. Whole-genome sequencing of P. falciparum has laid the foundation for significant biological advances by revealing surprising genomic information. The P. falciparum genome is extremely AT-rich (∼80%), with a substantial portion of genes encoding intragenic polyadenosine (polyA) tracks being expressed throughout the entire parasite life cycle. In most eukaryotes, intragenic polyA runs act as negative regulators of gene expression. Recent studies have shown that translation of mRNAs containing 12 or more consecutive adenosines results in ribosomal stalling and frameshifting; activating mRNA surveillance mechanisms. In contrast, P. falciparum translational machinery can efficiently and accurately translate polyA tracks without activating mRNA surveillance pathways. This unique feature of P. falciparum raises interesting questions: (1) How is P. falciparum able to efficiently and correctly translate polyA track transcripts, and (2) What are the specifics of the translational machinery and mRNA surveillance mechanisms that separate P. falciparum from other organisms? In this review, we analyze possible evolutionary shifts in P. falciparum protein synthesis machinery that allow efficient translation of an AU rich-transcriptome. We focus on physiological and structural differences of P. falciparum stage specific ribosomes, ribosome-associated proteins, and changes in mRNA surveillance mechanisms throughout the complete parasite life cycle, with an emphasis on the mosquito and liver stages.
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Affiliation(s)
| | - Sergej Djuranovic
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO, United States
| | - Slavica Pavlovic Djuranovic
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO, United States
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Arnot DE. Tying up Loose Ends in the Malaria Antigenic Variation Story. Trends Parasitol 2019; 35:588-590. [PMID: 31266710 DOI: 10.1016/j.pt.2019.06.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Accepted: 06/14/2019] [Indexed: 10/26/2022]
Abstract
A recent paper (Zhang et al., PLoS Biol., 2019) shines remarkable new light onto the malaria antigenic variation story. Using CRISPR/Cas9-targeted chromosome breaks and long-read whole-genome sequencing, they followed the fate of detached subtelomeric PfEMP1/var genes and demonstrated that these initiate cascades of recombination at sites far from the original break.
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Affiliation(s)
- David E Arnot
- Zhejiang University-University of Edinburgh (ZJE) Institute and Second Affiliated Hospital, Zhejiang University School of Medicine, China.
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Zhang X, Alexander N, Leonardi I, Mason C, Kirkman LA, Deitsch KW. Rapid antigen diversification through mitotic recombination in the human malaria parasite Plasmodium falciparum. PLoS Biol 2019; 17:e3000271. [PMID: 31083650 PMCID: PMC6532940 DOI: 10.1371/journal.pbio.3000271] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Revised: 05/23/2019] [Accepted: 04/30/2019] [Indexed: 11/18/2022] Open
Abstract
Malaria parasites possess the remarkable ability to maintain chronic infections that fail to elicit a protective immune response, characteristics that have stymied vaccine development and cause people living in endemic regions to remain at risk of malaria despite previous exposure to the disease. These traits stem from the tremendous antigenic diversity displayed by parasites circulating in the field. For Plasmodium falciparum, the most virulent of the human malaria parasites, this diversity is exemplified by the variant gene family called var, which encodes the major surface antigen displayed on infected red blood cells (RBCs). This gene family exhibits virtually limitless diversity when var gene repertoires from different parasite isolates are compared. Previous studies indicated that this remarkable genome plasticity results from extensive ectopic recombination between var genes during mitotic replication; however, the molecular mechanisms that direct this process to antigen-encoding loci while the rest of the genome remains relatively stable were not determined. Using targeted DNA double-strand breaks (DSBs) and long-read whole-genome sequencing, we show that a single break within an antigen-encoding region of the genome can result in a cascade of recombination events leading to the generation of multiple chimeric var genes, a process that can greatly accelerate the generation of diversity within this family. We also found that recombinations did not occur randomly, but rather high-probability, specific recombination products were observed repeatedly. These results provide a molecular basis for previously described structured rearrangements that drive diversification of this highly polymorphic gene family.
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Affiliation(s)
- Xu Zhang
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, New York, United States of America
| | - Noah Alexander
- Department of Physiology and Biophysics, Weill Cornell Medical College, New York, New York, United States of America
| | - Irina Leonardi
- Jill Roberts Center for Inflammatory Bowel Disease, Weill Cornell Medical College, New York, New York, United States of America
| | - Christopher Mason
- Department of Physiology and Biophysics, Weill Cornell Medical College, New York, New York, United States of America
- HRH Prince Alwaleed Bin Talal Bin Abdulaziz Alsaud Institute for Computational Biomedicine, Weill Cornell Medical College, New York, New York, United States of America
- Feil Family Brain and Mind Research Institute, Weill Cornell Medical College, New York, New York, United States of America
- WorldQuant Initiative for Quantitative Prediction, Weill Cornell Medical College, New York, New York, United States of America
| | - Laura A. Kirkman
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, New York, United States of America
- Department of Internal Medicine, Division of Infectious Diseases, Weill Cornell Medical College, New York, New York, United States of America
| | - Kirk W. Deitsch
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, New York, United States of America
- * E-mail:
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