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Kruse E, Göringer HU. Nanopore-Based Direct RNA Sequencing of the Trypanosoma brucei Transcriptome Identifies Novel lncRNAs. Genes (Basel) 2023; 14:genes14030610. [PMID: 36980882 PMCID: PMC10048164 DOI: 10.3390/genes14030610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2023] [Revised: 02/23/2023] [Accepted: 02/26/2023] [Indexed: 03/04/2023] Open
Abstract
Trypanosomatids are single-cell eukaryotic parasites. Unlike higher eukaryotes, they control gene expression post-transcriptionally and not at the level of transcription initiation. This involves all known cellular RNA circuits, from mRNA processing to mRNA decay, to translation, in addition to a large panel of RNA-interacting proteins that modulate mRNA abundance. However, other forms of gene regulation, for example by lncRNAs, cannot be excluded. LncRNAs are poorly studied in trypanosomatids, with only a single lncRNA characterized to date. Furthermore, it is not clear whether the complete inventory of trypanosomatid lncRNAs is known, because of the inherent cDNA-recoding and DNA-amplification limitations of short-read RNA sequencing. Here, we overcome these limitations by using long-read direct RNA sequencing (DRS) on nanopore arrays. We analyze the native RNA pool of the two main lifecycle stages of the African trypanosome Trypanosoma brucei, with a special emphasis on the inventory of lncRNAs. We identify 207 previously unknown lncRNAs, 32 of which are stage-specifically expressed. We also present insights into the complexity of the T. brucei transcriptome, including alternative transcriptional start and stop sites and potential transcript isoforms, to provide a bias-free understanding of the intricate RNA landscape in T. brucei.
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Characterization of Host-Specific Genes from Pine- and Grass-Associated Species of the Fusarium fujikuroi Species Complex. Pathogens 2022; 11:pathogens11080858. [PMID: 36014979 PMCID: PMC9415769 DOI: 10.3390/pathogens11080858] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 07/20/2022] [Accepted: 07/25/2022] [Indexed: 11/16/2022] Open
Abstract
The Fusarium fujikuroi species complex (FFSC) includes socioeconomically important pathogens that cause disease for numerous crops and synthesize a variety of secondary metabolites that can contaminate feedstocks and food. Here, we used comparative genomics to elucidate processes underlying the ability of pine-associated and grass-associated FFSC species to colonize tissues of their respective plant hosts. We characterized the identity, possible functions, evolutionary origins, and chromosomal positions of the host-range-associated genes encoded by the two groups of fungi. The 72 and 47 genes identified as unique to the respective genome groups were potentially involved in diverse processes, ranging from transcription, regulation, and substrate transport through to virulence/pathogenicity. Most genes arose early during the evolution of Fusarium/FFSC and were only subsequently retained in some lineages, while some had origins outside Fusarium. Although differences in the densities of these genes were especially noticeable on the conditionally dispensable chromosome of F. temperatum (representing the grass-associates) and F. circinatum (representing the pine-associates), the host-range-associated genes tended to be located towards the subtelomeric regions of chromosomes. Taken together, these results demonstrate that multiple mechanisms drive the emergence of genes in the grass- and pine-associated FFSC taxa examined. It also highlighted the diversity of the molecular processes potentially underlying niche-specificity in these and other Fusarium species.
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Cruz-Saavedra L, Schwabl P, Vallejo GA, Carranza JC, Muñoz M, Patino LH, Paniz-Mondolfi A, Llewellyn MS, Ramírez JD. Genome plasticity driven by aneuploidy and loss of heterozygosity in Trypanosoma cruzi. Microb Genom 2022; 8. [PMID: 35748878 PMCID: PMC9455712 DOI: 10.1099/mgen.0.000843] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Trypanosoma cruzi the causative agent of Chagas disease shows a marked genetic diversity and divided into at least six Discrete Typing Units (DTUs). High intra genetic variability has been observed in the TcI DTU, the most widely distributed DTU, where patterns of genomic diversity can provide information on ecological and evolutionary processes driving parasite population structure and genome organization. Chromosomal aneuploidies and rearrangements across multigene families represent an evidence of T. cruzi genome plasticity. We explored genomic diversity among 18 Colombian T. cruzi I clones and 15 T. cruzi I South American strains. Our results confirm high genomic variability, heterozygosity and presence of a clade compatible with the TcIdom genotype, described for strains from humans in Colombia and Venezuela. TcI showed high structural plasticity across the geographical region studied. Differential events of whole and segmental aneuploidy (SA) along chromosomes even between clones from the same strain were found and corroborated by the depth and allelic frequency. We detected loss of heterozygosity (LOH) events in different chromosomes, however, the size and location of segments under LOH varied between clones. Genes adjacent to breakpoints were evaluated, and retrotransposon hot spot genes flanked the beginning of segmental aneuploidies. Our results suggest that T. cruzi genomes, like those of Leishmania, may have a highly unstable structure and there is now an urgent need to design experiments to explore any potential adaptive role for the plasticity observed.
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Affiliation(s)
- Lissa Cruz-Saavedra
- Centro de Investigaciones en Microbiología y Biotecnología-UR (CIMBIUR), Facultad de Ciencias Naturales, Universidad del Rosario, Bogotá, Colombia
| | - Philipp Schwabl
- Institute of Biodiversity, Animal Health & Comparative Medicine, University of Glasgow, Glasgow G12 8QQ, UK
| | - Gustavo A Vallejo
- Laboratorio de Investigación en Parasitología Tropical, Facultad de Ciencias, Universidad del Tolima, Ibagué, Colombia
| | - Julio C Carranza
- Laboratorio de Investigación en Parasitología Tropical, Facultad de Ciencias, Universidad del Tolima, Ibagué, Colombia
| | - Marina Muñoz
- Centro de Investigaciones en Microbiología y Biotecnología-UR (CIMBIUR), Facultad de Ciencias Naturales, Universidad del Rosario, Bogotá, Colombia
| | - Luz Helena Patino
- Centro de Investigaciones en Microbiología y Biotecnología-UR (CIMBIUR), Facultad de Ciencias Naturales, Universidad del Rosario, Bogotá, Colombia
| | - Alberto Paniz-Mondolfi
- Molecular Microbiology Laboratory, Department of Pathology, Molecular and Cell-Based Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Martin S Llewellyn
- Institute of Biodiversity, Animal Health & Comparative Medicine, University of Glasgow, Glasgow G12 8QQ, UK
| | - Juan David Ramírez
- Centro de Investigaciones en Microbiología y Biotecnología-UR (CIMBIUR), Facultad de Ciencias Naturales, Universidad del Rosario, Bogotá, Colombia.,Molecular Microbiology Laboratory, Department of Pathology, Molecular and Cell-Based Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
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Kaur D, Agrahari M, Bhattacharya A, Bhattacharya S. The non-LTR retrotransposons of Entamoeba histolytica: genomic organization and biology. Mol Genet Genomics 2022; 297:1-18. [PMID: 34999963 DOI: 10.1007/s00438-021-01843-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2021] [Accepted: 11/26/2021] [Indexed: 11/24/2022]
Abstract
Genome sequence analysis of Entamoeba species revealed various classes of transposable elements. While E. histolytica and E. dispar are rich in non-long terminal repeat (LTR) retrotransposons, E. invadens contains predominantly DNA transposons. Non-LTR retrotransposons of E. histolytica constitute three families of long interspersed nuclear elements (LINEs), and their short, nonautonomous partners, SINEs. They occupy ~ 11% of the genome. The EhLINE1/EhSINE1 family is the most abundant and best studied. EhLINE1 is 4.8 kb, with two ORFs that encode functions needed for retrotransposition. ORF1 codes for the nucleic acid-binding protein, and ORF2 has domains for reverse transcriptase (RT) and endonuclease (EN). Most copies of EhLINEs lack complete ORFs. ORF1p is expressed constitutively, but ORF2p is not detected. Retrotransposition could be demonstrated upon ectopic over expression of ORF2p, showing that retrotransposition machinery is functional. The newly retrotransposed sequences showed a high degree of recombination. In transcriptomic analysis, RNA-Seq reads were mapped to individual EhLINE1 copies. Although full-length copies were transcribed, no full-length 4.8 kb transcripts were seen. Rather, sense transcripts mapped to ORF1, RT and EN domains. Intriguingly, there was strong antisense transcription almost exclusively from the RT domain. These unique features of EhLINE1 could serve to attenuate retrotransposition in E. histolytica.
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Gómez I, López MC, Rastrojo A, Lorenzo-Díaz F, Requena JM, Aguado B, Valladares B, Thomas MC. Variability of the Pr77 sequence of L1Tc retrotransposon among six T. cruzi strains belonging to different discrete typing units (DTUs). Acta Trop 2021; 222:106053. [PMID: 34273311 DOI: 10.1016/j.actatropica.2021.106053] [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: 12/05/2020] [Revised: 06/15/2021] [Accepted: 07/11/2021] [Indexed: 11/30/2022]
Abstract
All trypanosomatid genomes are colonized by non-LTR retrotransposons which exhibit a highly conserved 77-nt sequence at their 5' ends, known as the Pr77-hallmark (Pr77). The wide distribution of Pr77 is expected to be related to the gene regulation processes in these organisms as it has promoter and HDV-like ribozyme activities at the DNA and RNA levels, respectively. The identification of Pr77 hallmark-bearing retrotransposons and the study of the associations of mobile elements with relevant genes have been analyzed in the genomes of six strains of Trypanosoma cruzi belonging to different discrete typing units (DTUs) and with different geographical origins and host/vectors. The genomes have been sequenced, assembled and annotated. BUSCO analyses indicated a good quality for the assemblies that were used in comparative analyses. The results show differences among the six genomes in the copy number of genes related to virulence processes, the abundance of retrotransposons bearing the Pr77 sequence and the presence of the Pr77 hallmarks not associated with retroelements. The analyses also show frequent associations of Pr77-bearing retrotransposons and single Pr77 hallmarks with genes coding for trans-sialidases, RHS, MASP or hypothetical proteins, showing variable proportion depending on the type of retroelement, gene class and parasite strain. These differences in the genomic distribution of active retroelements and other Pr77-containing elements have shaped the genome architecture of these six strains and might be contributing to the phenotypic variability existing among them.
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Affiliation(s)
- Inmaculada Gómez
- Instituto de Parasitología y Biomedicina López-Neyra, Consejo Superior de Investigaciones Científicas; PTS-Granada, Spain
| | - Manuel Carlos López
- Instituto de Parasitología y Biomedicina López-Neyra, Consejo Superior de Investigaciones Científicas; PTS-Granada, Spain
| | - Alberto Rastrojo
- Centro de Biología Molecular Severo-Ochoa (CBMSO) (CSIC-UAM), Consejo Superior de Investigaciones Científicas, Universidad Autónoma de Madrid, Madrid, Spain
| | - Fabián Lorenzo-Díaz
- Instituto Universitario de Enfermedades Tropicales y Salud Pública de Canarias. Universidad de La Laguna. La Laguna, Spain
| | - José María Requena
- Centro de Biología Molecular Severo-Ochoa (CBMSO) (CSIC-UAM), Consejo Superior de Investigaciones Científicas, Universidad Autónoma de Madrid, Madrid, Spain
| | - Begoña Aguado
- Centro de Biología Molecular Severo-Ochoa (CBMSO) (CSIC-UAM), Consejo Superior de Investigaciones Científicas, Universidad Autónoma de Madrid, Madrid, Spain
| | - Basilio Valladares
- Instituto Universitario de Enfermedades Tropicales y Salud Pública de Canarias. Universidad de La Laguna. La Laguna, Spain
| | - M Carmen Thomas
- Instituto de Parasitología y Biomedicina López-Neyra, Consejo Superior de Investigaciones Científicas; PTS-Granada, Spain.
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Naguleswaran A, Fernandes P, Bevkal S, Rehmann R, Nicholson P, Roditi I. Developmental changes and metabolic reprogramming during establishment of infection and progression of Trypanosoma brucei brucei through its insect host. PLoS Negl Trop Dis 2021; 15:e0009504. [PMID: 34543277 PMCID: PMC8483307 DOI: 10.1371/journal.pntd.0009504] [Citation(s) in RCA: 10] [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: 05/11/2021] [Revised: 09/30/2021] [Accepted: 09/07/2021] [Indexed: 02/07/2023] Open
Abstract
Trypanosoma brucei ssp., unicellular parasites causing human and animal trypanosomiasis, are transmitted between mammals by tsetse flies. Periodic changes in variant surface glycoproteins (VSG), which form the parasite coat in the mammal, allow them to evade the host immune response. Different isolates of T. brucei show heterogeneity in their repertoires of VSG genes and have single nucleotide polymorphisms and indels that can impact on genome editing. T. brucei brucei EATRO1125 (AnTaR1 serodeme) is an isolate that is used increasingly often because it is pleomorphic in mammals and fly transmissible, two characteristics that have been lost by the most commonly used laboratory stocks. We present a genome assembly of EATRO1125, including contigs for the intermediate chromosomes and minichromosomes that serve as repositories of VSG genes. In addition, de novo transcriptome assemblies were performed using Illumina sequences from tsetse-derived trypanosomes. Reads of 150 bases enabled closely related members of multigene families to be discriminated. This revealed that the transcriptome of midgut-derived parasites is dynamic, starting with the expression of high affinity hexose transporters and glycolytic enzymes and then switching to proline uptake and catabolism. These changes resemble the transition from early to late procyclic forms in culture. Further metabolic reprogramming, including upregulation of tricarboxylic acid cycle enzymes, occurs in the proventriculus. Many transcripts upregulated in the salivary glands encode surface proteins, among them 7 metacyclic VSGs, multiple BARPs and GCS1/HAP2, a marker for gametes. A novel family of transmembrane proteins, containing polythreonine stretches that are predicted to be O-glycosylation sites, was also identified. Finally, RNA-Seq data were used to create an optimised annotation file with 5’ and 3’ untranslated regions accurately mapped for 9302 genes. We anticipate that this will be of use in identifying transcripts obtained by single cell sequencing technologies. Trypanosoma brucei ssp. are single-celled parasites that cause two tropical diseases: sleeping sickness in humans and nagana in domestic animals. Parasites survive in the host bloodstream because they periodically change their surface coats and also because they can switch from slender dividing forms to stumpy non-dividing forms. The latter can be transmitted to their second host, the tsetse fly. Although closely related, different geographical isolates differ in their repertoire of surface coats and have small, but important differences in their DNA sequences. In addition, laboratory strains that are transferred between mammals by needle passage lose the ability to produce stumpy forms and to infect flies. The isolate T. b. brucei EATRO1125 is often used for research as it produces stumpy forms and is fly transmissible. We provide an assembly of the genome of this isolate, including part of the repertoire of coat proteins, and a detailed analysis of the genes that the parasites express as they establish infection and progress through the fly. This has provided new insights into trypanosome biology. The combined genomic (DNA) and transcriptomic (RNA) data will be useful resources for the trypanosome research community.
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Affiliation(s)
| | - Paula Fernandes
- Institute of Cell Biology, University of Bern, Bern, Switzerland
- Graduate School of Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland
| | - Shubha Bevkal
- Institute of Cell Biology, University of Bern, Bern, Switzerland
- Graduate School of Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland
| | - Ruth Rehmann
- Institute of Cell Biology, University of Bern, Bern, Switzerland
| | - Pamela Nicholson
- Next Generation Sequencing Platform, University of Bern, Bern, Switzerland
| | - Isabel Roditi
- Institute of Cell Biology, University of Bern, Bern, Switzerland
- * E-mail:
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7
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Coutinho JVP, Rosa-Fernandes L, Mule SN, de Oliveira GS, Manchola NC, Santiago VF, Colli W, Wrenger C, Alves MJM, Palmisano G. The thermal proteome stability profile of Trypanosoma cruzi in epimastigote and trypomastigote life stages. J Proteomics 2021; 248:104339. [PMID: 34352427 DOI: 10.1016/j.jprot.2021.104339] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 06/24/2021] [Accepted: 07/28/2021] [Indexed: 12/18/2022]
Abstract
Trypanosoma cruzi is a flagellate protozoa being the etiological agent of Chagas disease, a neglected tropical disease, which still poses a public health problem worldwide. The intricate molecular changes during T. cruzi-host interaction have been explored using different largescale omics techniques. However, protein stability is largely unknown. Thermal proteome profiling (TPP) methodology has the potential to characterize proteome-wide stability highlighting key proteins during T. cruzi infection and life stage transition from the invertebrate to the mammalian host. In the present work, T. cruzi epimastigotes and trypomastigotes cell lysates were subjected to TPP workflow and analyzed by quantitative large-scale mass spectrometry-based proteomics to fit a melting profile for each protein. A total of 2884 proteins were identified and associated to 1741 melting curves being 1370 in trypomastigotes (TmAVG 53.53 °C) and 1279 in epimastigotes (TmAVG 50.89 °C). A total of 453 proteins were identified with statistically different melting profiles between the two life stages. Proteins associated to pathogenesis and intracellular transport had regulated melting temperatures. Membrane and glycosylated proteins had a higher average Tm in trypomastigotes compared to epimastigotes. This study represents the first large-scale comparison of parasite protein stability between life stages. SIGNIFICANCE: Trypanosoma cruzi, a unicellular flagellate parasite, is the etiological agent of Chagas disease, endemic in South America and affecting more that 7 million people worldwide. There is an intense research to identify novel chemotherapeutic and diagnostic targets of Chagas disease. Proteomic approaches have helped in elucidating the quantitative proteome and PTMs changes of T. cruzi during life cycle transition and upon different biotic and abiotic stimuli. However, a comprehensive knowledge of the protein-protein interaction and protein conformation is still missing. In order to fill this gap, this manuscript elucidates the T. cruzi Y strain proteome-wide thermal stability map in the epimastigote and trypomastigote life stages. Comparison between life stages showed a higher average melting temperature stability for trypomastigotes than epimastigotes indicating a host temperature adaptation. Both presented a selective thermal stability shift for cellular compartments, molecular functions and biological processes based on the T. cruzi life stage. Membrane and glycosylated proteins presented a higher thermal stability in trypomastigotes when compared to the epimastigotes.
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Affiliation(s)
- Joao V P Coutinho
- GlycoProteomics Laboratory, Department of Parasitology, Institute of Biomedical Sciences, University of Sao Paulo, Brazil
| | - Livia Rosa-Fernandes
- GlycoProteomics Laboratory, Department of Parasitology, Institute of Biomedical Sciences, University of Sao Paulo, Brazil
| | - Simon Ngao Mule
- GlycoProteomics Laboratory, Department of Parasitology, Institute of Biomedical Sciences, University of Sao Paulo, Brazil
| | - Gilberto Santos de Oliveira
- GlycoProteomics Laboratory, Department of Parasitology, Institute of Biomedical Sciences, University of Sao Paulo, Brazil
| | | | - Veronica Feijoli Santiago
- GlycoProteomics Laboratory, Department of Parasitology, Institute of Biomedical Sciences, University of Sao Paulo, Brazil
| | - Walter Colli
- Department of Biochemistry, Institute of Chemistry, University of Sao Paulo, Brazil
| | - Carsten Wrenger
- Unit for Drug Discovery, Department of Parasitology, Institute of Biomedical Sciences, University of Sao Paulo, Brazil
| | | | - Giuseppe Palmisano
- GlycoProteomics Laboratory, Department of Parasitology, Institute of Biomedical Sciences, University of Sao Paulo, Brazil.
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In Silico Identification of New Targets for Diagnosis, Vaccine, and Drug Candidates against Trypanosoma cruzi. DISEASE MARKERS 2021; 2020:9130719. [PMID: 33488847 PMCID: PMC7787821 DOI: 10.1155/2020/9130719] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Revised: 03/23/2020] [Accepted: 11/24/2020] [Indexed: 11/17/2022]
Abstract
Chagas disease is a neglected tropical disease caused by the parasite Trypanosoma cruzi. Despite the efforts and distinct methodologies, the search of antigens for diagnosis, vaccine, and drug targets for the disease is still needed. The present study is aimed at identifying possible antigens that could be used for diagnosis, vaccine, and drugs targets against T. cruzi using reverse vaccinology and molecular docking. The genomes of 28 T. cruzi strains available in GenBank (NCBI) were used to obtain the genomic core. Then, subtractive genomics was carried out to identify nonhomologous genes to the host in the core. A total of 2630 conserved proteins in 28 strains of T. cruzi were predicted using OrthoFinder and Diamond software, in which 515 showed no homology to the human host. These proteins were evaluated for their subcellular localization, from which 214 are cytoplasmic and 117 are secreted or present in the plasma membrane. To identify the antigens for diagnosis and vaccine targets, we used the VaxiJen software, and 14 nonhomologous proteins were selected showing high binding efficiency with MHC I and MHC II with potential for in vitro and in vivo tests. When these 14 nonhomologous molecules were compared against other trypanosomatids, it was found that the retrotransposon hot spot (RHS) protein is specific only for T. cruzi parasite suggesting that it could be used for Chagas diagnosis. Such 14 proteins were analyzed using the IEDB software to predict their epitopes in both B and T lymphocytes. Furthermore, molecular docking analysis was performed using the software MHOLline. As a result, we identified 6 possible T. cruzi drug targets that could interact with 4 compounds already known as antiparasitic activities. These 14 protein targets, along with 6 potential drug candidates, can be further validated in future studies, in vivo, regarding Chagas disease.
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Bevkal S, Naguleswaran A, Rehmann R, Kaiser M, Heller M, Roditi I. An Alba-domain protein required for proteome remodelling during trypanosome differentiation and host transition. PLoS Pathog 2021; 17:e1009239. [PMID: 33493187 PMCID: PMC7861527 DOI: 10.1371/journal.ppat.1009239] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 02/04/2021] [Accepted: 12/10/2020] [Indexed: 11/19/2022] Open
Abstract
The transition between hosts is a challenge for digenetic parasites as it is unpredictable. For Trypanosoma brucei subspecies, which are disseminated by tsetse flies, adaptation to the new host requires differentiation of stumpy forms picked up from mammals to procyclic forms in the fly midgut. Here we show that the Alba-domain protein Alba3 is not essential for mammalian slender forms, nor is it required for differentiation of slender to stumpy forms in culture or in mice. It is crucial, however, for the development of T. brucei procyclic forms during the host transition. While steady state levels of mRNAs in differentiating cells are barely affected by the loss of Alba3, there are major repercussions for the proteome. Mechanistically, Alba3 aids differentiation by rapidly releasing stumpy forms from translational repression and stimulating polysome formation. In its absence, parasites fail to remodel their proteome appropriately, lack components of the mitochondrial respiratory chain and show reduced infection of tsetse. Interestingly, Alba3 and the closely related Alba4 are functionally redundant in slender forms, but Alba4 cannot compensate for the lack of Alba3 during differentiation from the stumpy to the procyclic form. We postulate that Alba-domain proteins play similar roles in regulating translation in other protozoan parasites, in particular during life-cycle and host transitions. Trypanosoma brucei is a unicellular eukaryotic parasite that is responsible for African trypanosomiasis. The parasite needs two hosts, mammals and tsetse flies, in order to complete its life cycle. Throughout its developmental cycle, T. brucei encounters diverse environments to which it has to adapt in order to maintain its transmission and infectivity. Successful adaptation to the new environment and transition to different life-cycle stages are the general challenges faced by many digenetic parasites. In this study we show that the Alba-domain protein Alba3 is essential for differentiation of the mammalian stumpy form (transition form) to the procyclic form in the tsetse host. An Alba3 deletion mutant infects mice and shows characteristic waves of parasitaemia, but is severely compromised in its ability to infect tsetse flies. Stumpy forms are translationally repressed, but are poised to resume protein synthesis during differentiation. We show that Alba3 is key to efficient escape from translation repression; in its absence, there is a delay in the formation of polysomes and resumption of protein synthesis. This impacts the formation of procyclic-specific mitochondrial respiratory complex proteins as well as the repression of some bloodstream-specific proteins. This is the first time that a single protein has been shown to have a major influence on translation as an adaptive response to changing hosts. It is also the first time that a mechanism has been established for Alba-domain proteins in parasites.
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Affiliation(s)
- Shubha Bevkal
- Institute of Cell Biology, University of Bern, Bern, Switzerland
- Graduate School of Cellular and Biomedical Science, University of Bern, Bern, Switzerland
| | | | - Ruth Rehmann
- Institute of Cell Biology, University of Bern, Bern, Switzerland
| | - Marcel Kaiser
- Department of Medical and Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Manfred Heller
- Proteomics and Mass Spectrometry Core Facility, Department for BioMedical Research, University of Bern, Bern, Switzerland
| | - Isabel Roditi
- Institute of Cell Biology, University of Bern, Bern, Switzerland
- * E-mail:
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Abstract
The passage of mRNAs through the nuclear pores into the cytoplasm is essential in all eukaryotes. For regulation, mRNA export is tightly connected to the full machinery of nuclear mRNA processing, starting at transcription. Export competence of pre-mRNAs gradually increases by both transient and permanent interactions with multiple RNA processing and export factors. mRNA export is best understood in opisthokonts, with limited knowledge in plants and protozoa. Here, I review and compare nuclear mRNA processing and export between opisthokonts and Trypanosoma brucei. The parasite has many unusual features in nuclear mRNA processing, such as polycistronic transcription and trans-splicing. It lacks several nuclear complexes and nuclear-pore-associated proteins that in opisthokonts play major roles in mRNA export. As a consequence, trypanosome mRNA export control is not tight and export can even start co-transcriptionally. Whether trypanosomes regulate mRNA export at all, or whether leakage of immature mRNA to the cytoplasm is kept to a low level by a fast kinetics of mRNA processing remains to be investigated. mRNA export had to be present in the last common ancestor of eukaryotes. Trypanosomes are evolutionary very distant from opisthokonts and a comparison helps understanding the evolution of mRNA export.
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Genomic Organization and Generation of Genetic Variability in the RHS (Retrotransposon Hot Spot) Protein Multigene Family in Trypanosoma cruzi. Genes (Basel) 2020; 11:genes11091085. [PMID: 32957642 PMCID: PMC7563717 DOI: 10.3390/genes11091085] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 09/11/2020] [Accepted: 09/14/2020] [Indexed: 12/15/2022] Open
Abstract
Retrotransposon Hot Spot (RHS) is the most abundant gene family in Trypanosoma cruzi, with unknown function in this parasite. The aim of this work was to shed light on the organization and expression of RHS in T. cruzi. The diversity of the RHS protein family in T. cruzi was demonstrated by phylogenetic and recombination analyses. Transcribed sequences carrying the RHS domain were classified into ten distinct groups of monophyletic origin. We identified numerous recombination events among the RHS and traced the origins of the donors and target sequences. The transcribed RHS genes have a mosaic structure that may contain fragments of different RHS inserted in the target sequence. About 30% of RHS sequences are located in the subtelomere, a region very susceptible to recombination. The evolution of the RHS family has been marked by many events, including gene duplication by unequal mitotic crossing-over, homologous, as well as ectopic recombination, and gene conversion. The expression of RHS was analyzed by immunofluorescence and immunoblotting using anti-RHS antibodies. RHS proteins are evenly distributed in the nuclear region of T. cruzi replicative forms (amastigote and epimastigote), suggesting that they could be involved in the control of the chromatin structure and gene expression, as has been proposed for T. brucei.
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12
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Ramirez JL. Trypanosoma cruzi Genome 15 Years Later: What Has Been Accomplished? Trop Med Infect Dis 2020; 5:E129. [PMID: 32781761 PMCID: PMC7559697 DOI: 10.3390/tropicalmed5030129] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2020] [Revised: 08/03/2020] [Accepted: 08/04/2020] [Indexed: 11/16/2022] Open
Abstract
On 15 July 2020 was the 15th anniversary of the Science Magazine issue that reported three trypanosomatid genomes, namely Leishmania major, Trypanosoma brucei, and Trypanosoma cruzi. That publication was a milestone for the research community working with trypanosomatids, even more so, when considering that the first draft of the human genome was published only four years earlier after 15 years of research. Although nowadays, genome sequencing has become commonplace, the work done by researchers before that publication represented a huge challenge and a good example of international cooperation. Research in neglected diseases often faces obstacles, not only because of the unique characteristics of each biological model but also due to the lower funds the research projects receive. In the case of Trypanosoma cruzi the etiologic agent of Chagas disease, the first genome draft published in 2005 was not complete, and even after the implementation of more advanced sequencing strategies, to this date no final chromosomal map is available. However, the first genome draft enabled researchers to pick genes a la carte, produce proteins in vitro for immunological studies, and predict drug targets for the treatment of the disease or to be used in PCR diagnostic protocols. Besides, the analysis of the T. cruzi genome is revealing unique features about its organization and dynamics. In this work, I briefly summarize the actions of Latin American researchers that contributed to the first publication of the T. cruzi genome and discuss some features of the genome that may help to understand the parasite's robustness and adaptive capabilities.
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Affiliation(s)
- Jose Luis Ramirez
- Instituto de Estudios Avanzados, Caracas, Venezuela and Universidad Central de Venezuela, Caracas 1080, Venezuela
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Ramirez JL. An Evolutionary View of Trypanosoma Cruzi Telomeres. Front Cell Infect Microbiol 2020; 9:439. [PMID: 31998659 PMCID: PMC6967402 DOI: 10.3389/fcimb.2019.00439] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Accepted: 12/06/2019] [Indexed: 11/21/2022] Open
Abstract
Like in most eukaryotes, the linear chromosomes of Trypanosoma cruzi end in a nucleoprotein structure called the telomere, which is preceded by regions of variable length called subtelomeres. Together telomeres and subtelomeres are dynamic sites where DNA sequence rearrangements can occur without compromising essential interstitial genes or chromosomal synteny. Good examples of subtelomeres involvement are the expansion of human olfactory receptors genes, variant surface antigens in Trypanosoma brucei, and Saccharomyces cerevisiae mating types. T. cruzi telomeres are made of long stretches of the hexameric repeat 5′-TTAGGG-OH-3′, and its subtelomeres are enriched in genes and pseudogenes from the large gene families RHS, TS and DGF1, DEAD/H-RNA helicase and N-acetyltransferase, intermingled with sequences of retrotransposons elements. In particular, members of the Trans-sialidase type II family appear to have played a role in shaping the current T. cruzi telomere structure. Although the structure and function of T. cruzi telomeric and subtelomeric regions have been documented, recent experiments are providing new insights into T. cruzi's telomere-subtelomere dynamics. In this review, I discuss the co-evolution of telomere, subtelomeres and the TS gene family, and the role that these regions may have played in shaping T. cruzi's genome.
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Affiliation(s)
- Jose Luis Ramirez
- Fundación Instituto de Estudios Avanzados and United Nations University UNU-BIOLAC, Caracas, Venezuela
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Florini F, Naguleswaran A, Gharib WH, Bringaud F, Roditi I. Unexpected diversity in eukaryotic transcription revealed by the retrotransposon hotspot family of Trypanosoma brucei. Nucleic Acids Res 2019; 47:1725-1739. [PMID: 30544263 PMCID: PMC6393297 DOI: 10.1093/nar/gky1255] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Revised: 11/28/2018] [Accepted: 12/03/2018] [Indexed: 12/20/2022] Open
Abstract
The path from DNA to RNA to protein in eukaryotes is guided by a series of factors linking transcription, mRNA export and translation. Many of these are conserved from yeast to humans. Trypanosomatids, which diverged early in the eukaryotic lineage, exhibit unusual features such as polycistronic transcription and trans-splicing of all messenger RNAs. They possess basal transcription factors, but lack recognisable orthologues of many factors required for transcription elongation and mRNA export. We show that retrotransposon hotspot (RHS) proteins fulfil some of these functions and that their depletion globally impairs nascent RNA synthesis by RNA polymerase II. Three sub-families are part of a coordinated process in which RHS6 is most closely associated with chromatin, RHS4 is part of the Pol II complex and RHS2 connects transcription with the translation machinery. In summary, our results show that the components of eukaryotic transcription are far from being universal, and reveal unsuspected plasticity in the course of evolution.
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Affiliation(s)
- Francesca Florini
- Institute of Cell Biology, University of Bern, Bern, Switzerland.,Graduate School of Cellular and Biomedical Science, University of Bern, Bern, Switzerland
| | | | - Walid H Gharib
- Interfaculty Bioinformatics Unit, University of Bern, Switzerland
| | - Frédéric Bringaud
- Laboratoire de Microbiologie Fondamentale et Pathogénicité (MFP), UMR 5234 CNRS, Université de Bordeaux, France
| | - Isabel Roditi
- Institute of Cell Biology, University of Bern, Bern, Switzerland
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Abstract
In trypanosomes, RNA polymerase II transcription is polycistronic and individual mRNAs are excised by trans-splicing and polyadenylation. The lack of individual gene transcription control is compensated by control of mRNA processing, translation and degradation. Although the basic mechanisms of mRNA decay and translation are evolutionarily conserved, there are also unique aspects, such as the existence of six cap-binding translation initiation factor homologues, a novel decapping enzyme and an mRNA stabilizing complex that is recruited by RNA-binding proteins. High-throughput analyses have identified nearly a hundred regulatory mRNA-binding proteins, making trypanosomes valuable as a model system to investigate post-transcriptional regulation.
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Affiliation(s)
- Christine Clayton
- University of Heidelberg Center for Molecular Biology (ZMBH), Im Neuenheimer Feld 282, D69120 Heidelberg, Germany
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Xiong J, Yang W, Chen K, Jiang C, Ma Y, Chai X, Yan G, Wang G, Yuan D, Liu Y, Bidwell SL, Zafar N, Hadjithomas M, Krishnakumar V, Coyne RS, Orias E, Miao W. Hidden genomic evolution in a morphospecies-The landscape of rapidly evolving genes in Tetrahymena. PLoS Biol 2019; 17:e3000294. [PMID: 31158217 PMCID: PMC6564038 DOI: 10.1371/journal.pbio.3000294] [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: 10/02/2018] [Revised: 06/13/2019] [Accepted: 05/13/2019] [Indexed: 01/08/2023] Open
Abstract
A morphospecies is defined as a taxonomic species based wholly on morphology, but often morphospecies consist of clusters of cryptic species that can be identified genetically or molecularly. The nature of the evolutionary novelty that accompanies speciation in a morphospecies is an intriguing question. Morphospecies are particularly common among ciliates, a group of unicellular eukaryotes that separates 2 kinds of nuclei—the silenced germline nucleus (micronucleus [MIC]) and the actively expressed somatic nucleus (macronucleus [MAC])—within a common cytoplasm. Because of their very similar morphologies, members of the Tetrahymena genus are considered a morphospecies. We explored the hidden genomic evolution within this genus by performing a comprehensive comparative analysis of the somatic genomes of 10 species and the germline genomes of 2 species of Tetrahymena. These species show high genetic divergence; phylogenomic analysis suggests that the genus originated about 300 million years ago (Mya). Seven universal protein domains are preferentially included among the species-specific (i.e., the youngest) Tetrahymena genes. In particular, leucine-rich repeat (LRR) genes make the largest contribution to the high level of genome divergence of the 10 species. LRR genes can be sorted into 3 different age groups. Parallel evolutionary trajectories have independently occurred among LRR genes in the different Tetrahymena species. Thousands of young LRR genes contain tandem arrays of exactly 90-bp exons. The introns separating these exons show a unique, extreme phase 2 bias, suggesting a clonal origin and successive expansions of 90-bp–exon LRR genes. Identifying LRR gene age groups allowed us to document a Tetrahymena intron length cycle. The youngest 90-bp exon LRR genes in T. thermophila are concentrated in pericentromeric and subtelomeric regions of the 5 micronuclear chromosomes, suggesting that these regions act as genome innovation centers. Copies of a Tetrahymena Long interspersed element (LINE)-like retrotransposon are very frequently found physically adjacent to 90-bp exon/intron repeat units of the youngest LRR genes. We propose that Tetrahymena species have used a massive exon-shuffling mechanism, involving unequal crossing over possibly in concert with retrotransposition, to create the unique 90-bp exon array LRR genes. Genomic comparison of ten morphologically very similar species of ciliate from the genus Tetrahymena reveals how parallel microevolutionary processes have shaped their genomes and created unique genes through retrotransposition.
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Affiliation(s)
- Jie Xiong
- Key Laboratory of Aquatic Biodiversity and Conservation, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Wentao Yang
- Key Laboratory of Aquatic Biodiversity and Conservation, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Kai Chen
- Key Laboratory of Aquatic Biodiversity and Conservation, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Chuanqi Jiang
- Key Laboratory of Aquatic Biodiversity and Conservation, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Yang Ma
- Key Laboratory of Aquatic Biodiversity and Conservation, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Xiaocui Chai
- Key Laboratory of Aquatic Biodiversity and Conservation, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Guanxiong Yan
- Key Laboratory of Aquatic Biodiversity and Conservation, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Guangying Wang
- Key Laboratory of Aquatic Biodiversity and Conservation, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Dongxia Yuan
- Key Laboratory of Aquatic Biodiversity and Conservation, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | - Yifan Liu
- Department of Pathology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Shelby L. Bidwell
- J. Craig Venter Institute, Rockville, Maryland, United States of America
| | - Nikhat Zafar
- J. Craig Venter Institute, Rockville, Maryland, United States of America
| | | | - Vivek Krishnakumar
- J. Craig Venter Institute, Rockville, Maryland, United States of America
| | - Robert S. Coyne
- J. Craig Venter Institute, Rockville, Maryland, United States of America
| | - Eduardo Orias
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, California, United States of America
| | - Wei Miao
- Key Laboratory of Aquatic Biodiversity and Conservation, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
- University of Chinese Academy of Sciences, Beijing, China
- CAS Center for Excellence in Animal Evolution and Genetics, Kunming, China
- State Key Laboratory of Freshwater Ecology and Biotechnology of China, Wuhan, China
- * E-mail:
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Briggs E, Hamilton G, Crouch K, Lapsley C, McCulloch R. Genome-wide mapping reveals conserved and diverged R-loop activities in the unusual genetic landscape of the African trypanosome genome. Nucleic Acids Res 2018; 46:11789-11805. [PMID: 30304482 PMCID: PMC6294496 DOI: 10.1093/nar/gky928] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Revised: 09/25/2018] [Accepted: 10/05/2018] [Indexed: 01/09/2023] Open
Abstract
R-loops are stable RNA-DNA hybrids that have been implicated in transcription initiation and termination, as well as in telomere maintenance, chromatin formation, and genome replication and instability. RNA Polymerase (Pol) II transcription in the protozoan parasite Trypanosoma brucei is highly unusual: virtually all genes are co-transcribed from multigene transcription units, with mRNAs generated by linked trans-splicing and polyadenylation, and transcription initiation sites display no conserved promoter motifs. Here, we describe the genome-wide distribution of R-loops in wild type mammal-infective T. brucei and in mutants lacking RNase H1, revealing both conserved and diverged functions. Conserved localization was found at centromeres, rRNA genes and retrotransposon-associated genes. RNA Pol II transcription initiation sites also displayed R-loops, suggesting a broadly conserved role despite the lack of promoter conservation or transcription initiation regulation. However, the most abundant sites of R-loop enrichment were within the regions between coding sequences of the multigene transcription units, where the hybrids coincide with sites of polyadenylation and nucleosome-depletion. Thus, instead of functioning in transcription termination the most widespread localization of R-loops in T. brucei suggests a novel correlation with pre-mRNA processing. Finally, we find little evidence for correlation between R-loop localization and mapped sites of DNA replication initiation.
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Affiliation(s)
- Emma Briggs
- The Wellcome Centre for Molecular Parasitology, University of Glasgow, College of Medical, Veterinary and Life Sciences, Institute of Infection, Immunity and Inflammation, Sir Graeme Davies Building, 120 University Place, Glasgow G12 8TA, UK
| | - Graham Hamilton
- Glasgow Polyomics, University of Glasgow, Wolfson Wohl Cancer Research Centre, Garscube Estate, Switchback Rd, Bearsden, G61 1QH, UK
| | - Kathryn Crouch
- The Wellcome Centre for Molecular Parasitology, University of Glasgow, College of Medical, Veterinary and Life Sciences, Institute of Infection, Immunity and Inflammation, Sir Graeme Davies Building, 120 University Place, Glasgow G12 8TA, UK
| | - Craig Lapsley
- The Wellcome Centre for Molecular Parasitology, University of Glasgow, College of Medical, Veterinary and Life Sciences, Institute of Infection, Immunity and Inflammation, Sir Graeme Davies Building, 120 University Place, Glasgow G12 8TA, UK
| | - Richard McCulloch
- The Wellcome Centre for Molecular Parasitology, University of Glasgow, College of Medical, Veterinary and Life Sciences, Institute of Infection, Immunity and Inflammation, Sir Graeme Davies Building, 120 University Place, Glasgow G12 8TA, UK
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Amaro TMMM, Thilliez GJA, Motion GB, Huitema E. A Perspective on CRN Proteins in the Genomics Age: Evolution, Classification, Delivery and Function Revisited. FRONTIERS IN PLANT SCIENCE 2017; 8:99. [PMID: 28217133 PMCID: PMC5289972 DOI: 10.3389/fpls.2017.00099] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Accepted: 01/17/2017] [Indexed: 05/20/2023]
Abstract
Plant associated microbes rely on secreted virulence factors (effectors) to modulate host immunity and ensure progressive infection. Amongst the secreted protein repertoires defined and studied in pathogens to date, the CRNs (for CRinkling and Necrosis) have emerged as one of only a few highly conserved protein families, spread across several kingdoms. CRN proteins were first identified in plant pathogenic oomycetes where they were found to be modular factors that are secreted and translocated inside host cells by means of a conserved N-terminal domain. Subsequent localization and functional studies have led to the view that CRN C-termini execute their presumed effector function in the host nucleus, targeting processes required for immunity. These findings have led to great interest in this large protein family and driven the identification of additional CRN-like proteins in other organisms. The identification of CRN proteins and subsequent functional studies have markedly increased the number of candidate CRN protein sequences, expanded the range of phenotypes tentatively associated with function and revealed some of their molecular functions toward virulence. The increased number of characterized CRNs also has presented a set of challenges that may impede significant progress in the future. Here, we summarize our current understanding of the CRNs and re-assess some basic assumptions regarding this protein family. We will discuss the latest findings on CRN biology and highlight exciting new hypotheses that have emanated from the field. Finally, we will discuss new approaches to study CRN functions that would lead to a better understanding of CRN effector biology as well as the processes that lead to host susceptibility and immunity.
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Affiliation(s)
- Tiago M. M. M. Amaro
- Division of Plant Sciences, University of DundeeDundee, UK
- Dundee Effector ConsortiumDundee, UK
| | - Gaëtan J. A. Thilliez
- Division of Plant Sciences, University of DundeeDundee, UK
- Dundee Effector ConsortiumDundee, UK
- Cell and Molecular Sciences, The James Hutton InstituteInvergowrie, UK
| | - Graham B. Motion
- Division of Plant Sciences, University of DundeeDundee, UK
- Dundee Effector ConsortiumDundee, UK
| | - Edgar Huitema
- Division of Plant Sciences, University of DundeeDundee, UK
- Dundee Effector ConsortiumDundee, UK
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Khan MF, Shrivastava K, Sinha R, Kumar V, Jaitly AK. Genome wide occurrence and insertion preferences of INGI/RIME and SLACS CRE transposable elements in Trypanosoma brucei. Mob Genet Elements 2017; 6:e1240747. [PMID: 28090379 DOI: 10.1080/2159256x.2016.1240747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Revised: 09/18/2016] [Accepted: 09/20/2016] [Indexed: 10/20/2022] Open
Abstract
Retrotransposons play significant role in genome remodelling of T. brucei and about 5% of its genome consists of retrotransposons including INGI/RIME elements. INGI is one of the dispersed repetitive elements in T. brucei genome which is found distributed throughout all the chromosomes. SLACS (Spliced Leader Associated Conserved Sequence) however, is more conserved in its nature and lacks the typical poly-distributional pattern of LINE like transposons. We have found total 589 copies of these TEs with only 17.06 % (104 copies out of 589) copies with both ends intact thus showing a majority of truncated copies. Complete SLACS CRE were found only on chromosome 9, whereas, complete INGI/RIME were more ubiquitously distributed. The 50 - 70 bp upstream flanking sequence of these elements shows suitable nucleotide biophysical properties to favor transposition.
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Affiliation(s)
- Mohd Faheem Khan
- Department of Plant Sciences, M.J.P. Rohilkhand University, Bareilly, UP, India; Division of Animal Genetics, Indian Veterinary Research Institute, Izatnagar, Bareilly, UP, India
| | - Kush Shrivastava
- Division of Animal Genetics, Indian Veterinary Research Institute , Izatnagar, Bareilly, UP, India
| | - Rebeka Sinha
- Dairy Cattle Breeding Division, National Dairy Research Institute , Karnal, Haryana, India
| | - Virendra Kumar
- Department of Plant Sciences, M.J.P. Rohilkhand University , Bareilly, UP, India
| | - A K Jaitly
- Department of Plant Sciences, M.J.P. Rohilkhand University , Bareilly, UP, India
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Characterization and Diagnostic Application of Trypanosoma cruzi Trypomastigote Excreted-Secreted Antigens Shed in Extracellular Vesicles Released from Infected Mammalian Cells. J Clin Microbiol 2016; 55:744-758. [PMID: 27974541 DOI: 10.1128/jcm.01649-16] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Accepted: 11/11/2016] [Indexed: 01/05/2023] Open
Abstract
Chagas disease, caused by Trypanosoma cruzi, although endemic in many parts of Central and South America, is emerging as a global health threat through the potential contamination of blood supplies. Consequently, in the absence of a gold standard assay for the diagnosis of Chagas disease, additional antigens or strategies are needed. A proteomic analysis of the trypomastigote excreted-secreted antigens (TESA) associated with exosomal vesicles shed by T. cruzi identified ∼80 parasite proteins, with the majority being trans-sialidases. Mass spectrometry analysis of immunoprecipitation products performed using Chagas immune sera showed a marked enrichment in a subset of TESA proteins. Of particular relevance for diagnostic applications were the retrotransposon hot spot (RHS) proteins, which are absent in Leishmania spp., parasites that often confound diagnosis of Chagas disease. Interestingly, serological screens using recombinant RHS showed a robust immunoreactivity with sera from patients with clinical stages of Chagas ranging from asymptomatic to advance cardiomyopathy and this immunoreactivity was comparable to that of crude TESA. More importantly, no cross-reactivity with RHS was detected with sera from patients with malaria, leishmaniasis, toxoplasmosis, or African sleeping sickness, making this protein an attractive reagent for diagnosis of Chagas disease.
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Expression of profilin in Trypanosoma cruzi and identification of some of its ligands. Biochem Biophys Res Commun 2016; 480:709-714. [DOI: 10.1016/j.bbrc.2016.10.044] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 10/15/2016] [Indexed: 12/31/2022]
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Kariithi HM, Boeren S, Murungi EK, Vlak JM, Abd-Alla AMM. A proteomics approach reveals molecular manipulators of distinct cellular processes in the salivary glands of Glossina m. morsitans in response to Trypanosoma b. brucei infections. Parasit Vectors 2016; 9:424. [PMID: 27485005 PMCID: PMC4969678 DOI: 10.1186/s13071-016-1714-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Accepted: 07/20/2016] [Indexed: 12/28/2022] Open
Abstract
Background Glossina m. morsitans is the primary vector of the Trypanosoma brucei group, one of the causative agents of African trypanosomoses. The parasites undergo metacyclogenesis, i.e. transformation into the mammalian-infective metacyclic trypomastigote (MT) parasites, in the salivary glands (SGs) of the tsetse vector. Since the MT-parasites are largely uncultivable in vitro, information on the molecular processes that facilitate metacyclogenesis is scanty. Methods To bridge this knowledge gap, we employed tandem mass spectrometry to investigate protein expression modulations in parasitized (T. b. brucei-infected) and unparasitized SGs of G. m. morsitans. We annotated the identified proteins into gene ontologies and mapped the up- and downregulated proteins within protein-protein interaction (PPI) networks. Results We identified 361 host proteins, of which 76.6 % (n = 276) and 22.3 % (n = 81) were up- and downregulated, respectively, in parasitized SGs compared to unparasitized SGs. Whilst 32 proteins were significantly upregulated (> 10-fold), only salivary secreted adenosine was significantly downregulated. Amongst the significantly upregulated proteins, there were proteins associated with blood feeding, immunity, cellular proliferation, homeostasis, cytoskeletal traffic and regulation of protein turnover. The significantly upregulated proteins formed major hubs in the PPI network including key regulators of the Ras/MAPK and Ca2+/cAMP signaling pathways, ubiquitin-proteasome system and mitochondrial respiratory chain. Moreover, we identified 158 trypanosome-specific proteins, notable of which were proteins in the families of the GPI-anchored surface glycoproteins, kinetoplastid calpains, peroxiredoxins, retrotransposon host spot multigene and molecular chaperones. Whilst immune-related trypanosome proteins were over-represented, membrane transporters and proteins involved in translation repression (e.g. ribosomal proteins) were under-represented, potentially reminiscent of the growth-arrested MT-parasites. Conclusions Our data implicate the significantly upregulated proteins as manipulators of diverse cellular processes in response to T. b. brucei infection, potentially to prepare the MT-parasites for invasion and evasion of the mammalian host immune defences. We discuss potential strategies to exploit our findings in enhancement of trypanosome refractoriness or reduce the vector competence of the tsetse vector. Electronic supplementary material The online version of this article (doi:10.1186/s13071-016-1714-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Henry M Kariithi
- Biotechnology Research Institute, Kenya Agricultural and Livestock Research Organization, P.O Box 57811, 00200, Kaptagat Rd, Loresho, Nairobi, Kenya. .,Insect Pest Control Laboratories, Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture, International Atomic Energy Agency, Wagrammer Straße 5, Vienna, Austria.
| | - Sjef Boeren
- Laboratory of Biochemistry, Wageningen University, Dreijenlaan 3, 6703, HA, Wageningen, The Netherlands
| | - Edwin K Murungi
- Department of Biochemistry and Molecular Biology, Egerton University, P.O. Box 536, 20115, Njoro, Kenya
| | - Just M Vlak
- Laboratory of Virology, Wageningen University, Droevendaalsesteeg 1, 6708, PB, Wageningen, The Netherlands
| | - Adly M M Abd-Alla
- Insect Pest Control Laboratories, Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture, International Atomic Energy Agency, Wagrammer Straße 5, Vienna, Austria.
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Zhang D, Burroughs AM, Vidal ND, Iyer LM, Aravind L. Transposons to toxins: the provenance, architecture and diversification of a widespread class of eukaryotic effectors. Nucleic Acids Res 2016; 44:3513-33. [PMID: 27060143 PMCID: PMC4857004 DOI: 10.1093/nar/gkw221] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Accepted: 03/22/2016] [Indexed: 01/13/2023] Open
Abstract
Enzymatic effectors targeting nucleic acids, proteins and other cellular components are the mainstay of conflicts across life forms. Using comparative genomics we identify a large class of eukaryotic proteins, which include effectors from oomycetes, fungi and other parasites. The majority of these proteins have a characteristic domain architecture with one of several N-terminal 'Header' domains, which are predicted to play a role in trafficking of these effectors, including a novel version of the Ubiquitin fold. The Headers are followed by one or more diverse C-terminal domains, such as restriction endonuclease (REase), protein kinase, HNH endonuclease, LK-nuclease (a RNase) and multiple distinct peptidase domains, which are predicted to carry their toxicity determinants. The most common types of these proteins appear to have originated from prokaryotic transposases (e.g. TN7 and Mu) and combine a CDC6/ORC1-STAND clade NTPase domain with a C-terminal REase domain. Other than the so-called Crinkler effectors of oomycetes and fungi, these effectors are encoded by other eukaryotic parasites such as trypanosomatids (the RHS proteins) and the rhizarian Plasmodiophora, and symbionts like Capsaspora Remarkably, we also find these proteins in free-living eukaryotes, including several viridiplantae, fungi, amoebozoans and animals. These versions might either still be transposons or function in other poorly understood eukaryote-specific inter-organismal and inter-genomic conflicts. These include the Medea1 selfish element of Tribolium that spreads via post-zygotic killing. We present a unified mechanism for the recombination-dependent diversification and action of this widespread class of molecular weaponry deployed across diverse conflicts ranging from parasitic to free-living forms.
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Affiliation(s)
- Dapeng Zhang
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA
| | - A Maxwell Burroughs
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA
| | - Newton D Vidal
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA
| | - Lakshminarayan M Iyer
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA
| | - L Aravind
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA
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Richardson JB, Evans B, Pyana PP, Van Reet N, Sistrom M, Büscher P, Aksoy S, Caccone A. Whole genome sequencing shows sleeping sickness relapse is due to parasite regrowth and not reinfection. Evol Appl 2016; 9:381-93. [PMID: 26834831 PMCID: PMC4721075 DOI: 10.1111/eva.12338] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2015] [Accepted: 09/29/2015] [Indexed: 11/27/2022] Open
Abstract
The trypanosome Trypanosoma brucei gambiense (Tbg) is a cause of human African trypanosomiasis (HAT) endemic to many parts of sub-Saharan Africa. The disease is almost invariably fatal if untreated and there is no vaccine, which makes monitoring and managing drug resistance highly relevant. A recent study of HAT cases from the Democratic Republic of the Congo reported a high incidence of relapses in patients treated with melarsoprol. Of the 19 Tbg strains isolated from patients enrolled in this study, four pairs were obtained from the same patient before treatment and after relapse. We used whole genome sequencing to investigate whether these patients were infected with a new strain, or if the original strain had regrown to pathogenic levels. Clustering analysis of 5938 single nucleotide polymorphisms supports the hypothesis of regrowth of the original strain, as we found that strains isolated before and after treatment from the same patient were more similar to each other than to other isolates. We also identified 23 novel genes that could affect melarsoprol sensitivity, representing a promising new set of targets for future functional studies. This work exemplifies the utility of using evolutionary approaches to provide novel insights and tools for disease control.
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Affiliation(s)
- Joshua B Richardson
- Department of Ecology and Evolutionary Biology Yale University New Haven CT USA
| | - Benjamin Evans
- Department of Ecology and Evolutionary Biology Yale University New Haven CT USA
| | - Patient P Pyana
- Department de Parasitologie Institut National de Recherche Biomedicale Kinshasa Gombe Democratic Republic of the Congo
| | - Nick Van Reet
- Department of Biomedical Sciences Institute of Tropical Medicine Antwerp Belgium
| | - Mark Sistrom
- School of Natural Sciences University of California Merced Merced CA USA
| | - Philippe Büscher
- Department of Biomedical Sciences Institute of Tropical Medicine Antwerp Belgium
| | - Serap Aksoy
- Department of Epidemiology and Public Health Yale School of Public Health New Haven CT USA
| | - Adalgisa Caccone
- Department of Ecology and Evolutionary Biology Yale University New Haven CT USA
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Abstract
Replication of Trypanosoma cruzi, the etiological agent of Chagas disease, displays peculiar features, such as absence of chromosome condensation and closed mitosis. Although previous proteome and subproteome analyses of T. cruzi have been carried out, the nuclear subproteome of this protozoan has not been described. Here, we report, for the first time to the best of our knowledge, the isolation and proteome analysis of T. cruzi nuclear fraction. For that, T. cruzi epimastigote cells were lysed and subjected to cell fractionation using two steps of sucrose density gradient centrifugation. The purity of the nuclear fraction was confirmed by phase contrast and fluorescence microscopy. Liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) allowed the identification of 864 proteins. Among those, 272 proteins were annotated as putative uncharacterized, and 275 had not been previously reported on global T. cruzi proteome analysis. Additionally, to support our enrichment method, bioinformatics analysis in DAVID was carried out. It grouped the nuclear proteins in 65 gene clusters, wherein the clusters with the highest enrichment scores harbor members with chromatin organization and DNA binding functions.
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Abstract
TbRRM1 of Trypanosoma brucei is a nucleoprotein that was previously identified in a search for splicing factors in T. brucei. We show that TbRRM1 associates with mRNAs and with the auxiliary splicing factor polypyrimidine tract-binding protein 2, but not with components of the core spliceosome. TbRRM1 also interacts with several retrotransposon hot spot (RHS) proteins and histones. RNA immunoprecipitation of a tagged form of TbRRM1 from procyclic (insect) form trypanosomes identified ca. 1,500 transcripts that were enriched and 3,000 transcripts that were underrepresented compared to cellular mRNA. Enriched transcripts encoded RNA-binding proteins, including TbRRM1 itself, several RHS transcripts, mRNAs with long coding regions, and a high proportion of stage-regulated mRNAs that are more highly expressed in bloodstream forms. Transcripts encoding ribosomal proteins, other factors involved in translation, and procyclic-specific transcripts were underrepresented. Knockdown of TbRRM1 by RNA interference caused widespread changes in mRNA abundance, but these changes did not correlate with the binding of the protein to transcripts, and most splice sites were unchanged, negating a general role for TbRRM1 in splice site selection. When changes in mRNA abundance were mapped across the genome, regions with many downregulated mRNAs were identified. Two regions were analyzed by chromatin immunoprecipitation, both of which exhibited increases in nucleosome occupancy upon TbRRM1 depletion. In addition, subjecting cells to heat shock resulted in translocation of TbRRM1 to the cytoplasm and compaction of chromatin, consistent with a second role for TbRRM1 in modulating chromatin structure. Trypanosoma brucei, the parasite that causes human sleeping sickness, is transmitted by tsetse flies. The parasite progresses through different life cycle stages in its two hosts, altering its pattern of gene expression in the process. In trypanosomes, protein-coding genes are organized as polycistronic units that are processed into monocistronic mRNAs. Since genes in the same unit can be regulated independently of each other, it is believed that gene regulation is essentially posttranscriptional. In this study, we investigated the role of a nuclear RNA-binding protein, TbRRM1, in the insect stage of the parasite. We found that TbRRM1 binds nuclear mRNAs and also affects chromatin status. Reduction of nuclear TbRRM1 by RNA interference or heat shock resulted in chromatin compaction. We propose that TbRRM1 regulates RNA polymerase II-driven gene expression both cotranscriptionally, by facilitating transcription and efficient splicing, and posttranscriptionally, via its interaction with nuclear mRNAs.
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Sistrom M, Evans B, Bjornson R, Gibson W, Balmer O, Mäser P, Aksoy S, Caccone A. Comparative genomics reveals multiple genetic backgrounds of human pathogenicity in the Trypanosoma brucei complex. Genome Biol Evol 2014; 6:2811-9. [PMID: 25287146 PMCID: PMC4224348 DOI: 10.1093/gbe/evu222] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The Trypanosoma brucei complex contains a number of subspecies with exceptionally variable life histories, including zoonotic subspecies, which are causative agents of human African trypanosomiasis (HAT) in sub-Saharan Africa. Paradoxically, genomic variation between taxa is extremely low. We analyzed the whole-genome sequences of 39 isolates across the T. brucei complex from diverse hosts and regions, identifying 608,501 single nucleotide polymorphisms that represent 2.33% of the nuclear genome. We show that human pathogenicity occurs across a wide range of parasite genotypes, and taxonomic designation does not reflect genetic variation across the group, as previous studies have suggested based on a small number of genes. This genome-wide study allowed the identification of significant host and geographic location associations. Strong purifying selection was detected in genomic regions associated with cytoskeleton structure, and regulatory genes associated with antigenic variation, suggesting conservation of these regions in African trypanosomes. In agreement with expectations drawn from meiotic reciprocal recombination, differences in average linkage disequilibrium between chromosomes in T. brucei correlate positively with chromosome size. In addition to insights into the life history of a diverse group of eukaryotic parasites, the documentation of genomic variation across the T. brucei complex and its association with specific hosts and geographic localities will aid in the development of comprehensive monitoring tools crucial to the proposed elimination of HAT by 2020, and on a shorter term, for monitoring the feared merger between the two human infective parasites, T. brucei rhodesiense and T. b. gambiense, in northern Uganda.
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Affiliation(s)
- Mark Sistrom
- Department of Ecology and Evolutionary Biology, Yale University
| | - Benjamin Evans
- Department of Ecology and Evolutionary Biology, Yale University
| | | | - Wendy Gibson
- School of Biological Sciences, University of Bristol, United Kingdom
| | - Oliver Balmer
- Swiss Tropical and Public Health Institute, Basel, Switzerland Zoological Institute, University of Basel, Switzerland
| | - Pascal Mäser
- Swiss Tropical and Public Health Institute, Basel, Switzerland
| | - Serap Aksoy
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT
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Cross GAM, Kim HS, Wickstead B. Capturing the variant surface glycoprotein repertoire (the VSGnome) of Trypanosoma brucei Lister 427. Mol Biochem Parasitol 2014; 195:59-73. [PMID: 24992042 DOI: 10.1016/j.molbiopara.2014.06.004] [Citation(s) in RCA: 133] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2014] [Revised: 06/19/2014] [Accepted: 06/23/2014] [Indexed: 11/30/2022]
Abstract
Trypanosoma brucei evades the adaptive immune response through the expression of antigenically distinct Variant Surface Glycoprotein (VSG) coats. To understand the progression and mechanisms of VSG switching, and to identify the VSGs expressed in populations of trypanosomes, it is desirable to predetermine the available repertoire of VSG genes (the 'VSGnome'). To date, the catalog of VSG genes present in any strain is far from complete and the majority of current information regarding VSGs is derived from the TREU927 strain that is not commonly used as an experimental model. We have assembled, annotated and analyzed 2563 distinct and previously unsequenced genes encoding complete and partial VSGs of the widely used Lister 427 strain of T. brucei. Around 80% of the VSGnome consists of incomplete genes or pseudogenes. Read-depth analysis demonstrated that most VSGs exist as single copies, but 360 exist as two or more indistinguishable copies. The assembled regions include five functional metacyclic VSG expression sites. One third of minichromosome sub-telomeres contain a VSG (64-67 VSGs on ∼96 minichromosomes), of which 85% appear to be functionally competent. The minichromosomal repertoire is very dynamic, differing among clones of the same strain. Few VSGs are unique along their entire length: frequent recombination events are likely to have shaped (and to continue to shape) the repertoire. In spite of their low sequence conservation and short window of expression, VSGs show evidence of purifying selection, with ∼40% of non-synonymous mutations being removed from the population. VSGs show a strong codon-usage bias that is distinct from that of any other group of trypanosome genes. VSG sequences are generally very divergent between Lister 427 and TREU927 strains of T. brucei, but those that are highly similar are not found in 'protected' genomic environments, but may reflect genetic exchange among populations.
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Affiliation(s)
- George A M Cross
- Laboratory of Molecular Parasitology, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA.
| | - Hee-Sook Kim
- Laboratory of Molecular Parasitology, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA.
| | - Bill Wickstead
- Medical School, Queen's Medical Centre, University of Nottingham, Nottingham NG7 2UH, UK.
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Silva Galdino T, Menna-Barreto RFS, Britto C, Samudio F, Brandão A, Kalume DE. Cell disruption using a different methodology for proteomics analysis of Trypanosoma cruzi strains. Anal Biochem 2013; 448:1-8. [PMID: 24291641 DOI: 10.1016/j.ab.2013.11.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2013] [Revised: 10/28/2013] [Accepted: 11/07/2013] [Indexed: 01/23/2023]
Abstract
We have developed a cell disruption method to produce a protein extract using Trypanosoma cruzi cells based on a straightforward hypoosmotic lysis protocol. The procedure consists of three steps: incubation of the cells in a hypoosmotic lysis buffer, sonication in a water bath, and centrifugation. The final protein extract was designated TcS12. The stages of cell disruption at different incubation times were monitored by differential interference contrast microscopy. After 30min of incubation in lysis buffer at 4°C, the T. cruzi epimastigote forms changed from slender to round-shaped parasites. Nevertheless, cell disruption took place following sonication of the sample for 30min. The efficiency of the methodology was also validated by flow cytometry, which resulted in 72% of propidium iodide (PI)-labeled cells. To estimate the protein extraction yield and the differential protein expression, the proteomics profile of four T. cruzi strains (CL-Brener, Dm28c, Y, and 4167) were analyzed by liquid chromatography tandem mass spectrometry (LCMS/MS) on a SYNAPT HDMS system using the label-free MS(E) approach. ProteinLynx Global Server (version 2.5) with Expression(E) analysis identified a total of 1153 proteins and revealed 428 differentially expressed proteins among the strains. Gene ontology analysis showed that not only cytosolic proteins but also nuclear and organellar ones were present in the extract.
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Affiliation(s)
- Tainah Silva Galdino
- Laboratório Interdisciplinar de Pesquisas Médicas, Instituto Oswaldo Cruz (IOC), Fundação Oswaldo Cruz (FIOCRUZ), 21040-360 Manguinhos, Rio de Janeiro, RJ, Brazil
| | - Rubem Figueiredo Sadok Menna-Barreto
- Laboratório de Biologia Celular, Instituto Oswaldo Cruz (IOC), Fundação Oswaldo Cruz (FIOCRUZ), 21040-360 Manguinhos, Rio de Janeiro, RJ, Brazil
| | - Constança Britto
- Laboratório de Biologia Molecular e Doenças Endêmicas, Instituto Oswaldo Cruz (IOC), Fundação Oswaldo Cruz (FIOCRUZ), 21040-360 Manguinhos, Rio de Janeiro, RJ, Brazil
| | - Franklyn Samudio
- Laboratório Interdisciplinar de Pesquisas Médicas, Instituto Oswaldo Cruz (IOC), Fundação Oswaldo Cruz (FIOCRUZ), 21040-360 Manguinhos, Rio de Janeiro, RJ, Brazil; Laboratório de Parasitologia, Instituto Conmemorativo Gorgas de Estudios de la Salud (ICGES), 0816-02593, Panama
| | - Adeilton Brandão
- Laboratório Interdisciplinar de Pesquisas Médicas, Instituto Oswaldo Cruz (IOC), Fundação Oswaldo Cruz (FIOCRUZ), 21040-360 Manguinhos, Rio de Janeiro, RJ, Brazil
| | - Dário Eluan Kalume
- Laboratório Interdisciplinar de Pesquisas Médicas, Instituto Oswaldo Cruz (IOC), Fundação Oswaldo Cruz (FIOCRUZ), 21040-360 Manguinhos, Rio de Janeiro, RJ, Brazil.
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Okalang U, Nanteza A, Matovu E, Lubega GW. Identification of coding sequences from a freshly prepared Trypanosoma brucei brucei expression library by polymerase chain reaction. INTERNATIONAL JOURNAL OF BIOCHEMISTRY AND MOLECULAR BIOLOGY 2013; 4:73-82. [PMID: 23936738 PMCID: PMC3729254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 05/25/2013] [Accepted: 07/06/2013] [Indexed: 06/02/2023]
Abstract
Animal African trypanosomiasis (AAT) also known as Nagana is a devastating disease among domestic animals in large parts of Sub-Saharan Africa causing loses in milk and meat production as well as traction power. However, there is currently no commercial vaccine against AAT. The parasites have also developed resistance to some of the drugs in use. Moreover, the use of affordable computer-aided wet bench methods in the search for vaccine and/or new drug targets against this disease have not yet been fully explored in developing countries. This study, therefore, explored the use of PCR to screen a freshly prepared bloodstream form Trypanosoma brucei brucei (T. b. brucei) expression library for coding sequences followed by bioinformatics analyses specifying the functions and importance of these proteins to parasite survival. Eleven protein coding sequences were identified from twenty nine purified clones. The putative retro transposon hot spot protein 4 (RHSP 4) was the only protein with a fully annotated DNA sequence. All the others were hypothetical or had partial or unqualified annotations. RHSP 4 and pyruvate dehydrogenase E1 component, alpha sub-unit (PDE1α) are involved in aerobic respiration whereas succinyl-Co A-3-ketoacid-coenzyme A transferase mitochondrial precursor (SKTMP) is predicted to be involved in ketone body catabolism. Cystathionine beta-synthase (CBS) and alpha-1,3-mannosyltransferase (αMT) have been predicted in cysteine biosynthesis and vesicular transport respectively. The functions of the hypothetical proteins encountered have neither been experimentally determined nor predicted. We hypothesize that both CBS and PDE1α are good drug targets. Overall, about 300 plates are required to PCR screen the entire Trypanosoma brucei genome in approximately eight months. This method is therefore, applicable and affordable in the search for new drug targets under conditions of limited resources among developing countries.
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Affiliation(s)
- Uthman Okalang
- Department of Biology, Faculty of Science and Education, Busitema UniversityTororo, Uganda
| | - Ann Nanteza
- Department of Biomolecular Resources and Biolaboratory Sciences, Animal Resources and Biosecurity, College of Veterinary Medicine, Makerere UniversityKampala, Uganda
| | - Enock Matovu
- Department of Biomolecular Resources and Biolaboratory Sciences, Animal Resources and Biosecurity, College of Veterinary Medicine, Makerere UniversityKampala, Uganda
| | - George W Lubega
- Department of Biomolecular Resources and Biolaboratory Sciences, Animal Resources and Biosecurity, College of Veterinary Medicine, Makerere UniversityKampala, Uganda
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31
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Zheng LL, Wen YZ, Yang JH, Liao JY, Shao P, Xu H, Zhou H, Wen JZ, Lun ZR, Ayala FJ, Qu LH. Comparative transcriptome analysis of small noncoding RNAs in different stages of Trypanosoma brucei. RNA (NEW YORK, N.Y.) 2013; 19:863-875. [PMID: 23704326 PMCID: PMC3683921 DOI: 10.1261/rna.035683.112] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/27/2012] [Accepted: 03/12/2013] [Indexed: 06/02/2023]
Abstract
Trypanosoma brucei, a pathogen of human and domestic animals, is an early evolved parasitic protozoan with a complex life cycle. Most genes of this parasite are post-transcriptionally regulated. However, the mechanisms and the molecules involved remain largely unknown. We have deep-sequenced the small RNAs of two life stages of this parasite--the bloodstream form and the procyclic form. Our results show that the small RNAs of T. brucei could derive from multiple sources, including NATs (natural antisense transcripts), tRNAs, and rRNAs. Most of these small RNAs in the two stages were found to share uniform characteristics. However, our results demonstrate that their variety and expression show significant differences between different stages, indicating possible functional differentiation. Dicer-knockdown evidence further proved that some of the small interfering RNAs (siRNAs) could regulate the expression of genes. Based on the genome-wide analysis of the small RNAs in the two stages of T. brucei, our results not only provide evidence to study their differentiation but also shed light on questions regarding the origins and evolution of small RNA-based mechanisms in early eukaryotes.
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MESH Headings
- Base Sequence
- Computational Biology
- Evolution, Molecular
- Gene Expression Profiling/methods
- Gene Expression Regulation
- Genes, Protozoan
- High-Throughput Nucleotide Sequencing
- Molecular Sequence Data
- RNA, Protozoan/genetics
- RNA, Protozoan/metabolism
- RNA, Small Interfering/genetics
- RNA, Small Interfering/metabolism
- RNA, Small Untranslated/genetics
- RNA, Small Untranslated/metabolism
- RNA, Transfer/genetics
- RNA, Transfer/metabolism
- Ribonuclease III/genetics
- Ribonuclease III/metabolism
- Trypanosoma brucei brucei/genetics
- Trypanosoma brucei brucei/metabolism
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Affiliation(s)
- Ling-Ling Zheng
- State Key Laboratory of Biocontrol, Key Laboratory of Gene Engineering, Ministry of Education, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, China
| | - Yan-Zi Wen
- Key Laboratory of Tropical Disease and Control, Ministry of Education, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou 510080, China
| | - Jian-Hua Yang
- State Key Laboratory of Biocontrol, Key Laboratory of Gene Engineering, Ministry of Education, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, China
| | - Jian-You Liao
- State Key Laboratory of Biocontrol, Key Laboratory of Gene Engineering, Ministry of Education, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, China
| | - Peng Shao
- State Key Laboratory of Biocontrol, Key Laboratory of Gene Engineering, Ministry of Education, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, China
| | - Hui Xu
- State Key Laboratory of Biocontrol, Key Laboratory of Gene Engineering, Ministry of Education, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, China
| | - Hui Zhou
- State Key Laboratory of Biocontrol, Key Laboratory of Gene Engineering, Ministry of Education, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, China
| | - Jun-Zhi Wen
- State Key Laboratory of Biocontrol, Key Laboratory of Gene Engineering, Ministry of Education, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, China
| | - Zhao-Rong Lun
- State Key Laboratory of Biocontrol, Key Laboratory of Gene Engineering, Ministry of Education, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, China
- Key Laboratory of Tropical Disease and Control, Ministry of Education, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou 510080, China
- Centre for Parasitology and Disease, School of Environment and Life Sciences, University of Salford, Salford M5 4WT, United Kingdom
| | - Francisco J. Ayala
- Department of Ecology and Evolutionary Biology, University of California, Irvine, California 92697, USA
| | - Liang-Hu Qu
- State Key Laboratory of Biocontrol, Key Laboratory of Gene Engineering, Ministry of Education, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, China
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32
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Minaya M, Pimentel M, Mason-Gamer R, Catalan P. Distribution and evolutionary dynamics of Stowaway Miniature Inverted repeat Transposable Elements (MITEs) in grasses. Mol Phylogenet Evol 2013; 68:106-18. [DOI: 10.1016/j.ympev.2013.03.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2012] [Revised: 03/02/2013] [Accepted: 03/06/2013] [Indexed: 12/24/2022]
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Povelones ML, Tiengwe C, Gluenz E, Gull K, Englund PT, Jensen RE. Mitochondrial shape and function in trypanosomes requires the outer membrane protein, TbLOK1. Mol Microbiol 2013; 87:713-29. [PMID: 23336702 DOI: 10.1111/mmi.12089] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/03/2012] [Indexed: 01/01/2023]
Abstract
In an RNAi library screen for loss of kinetoplast DNA (kDNA), we identified an uncharacterized Trypanosoma brucei protein, named TbLOK1, required for maintenance of mitochondrial shape and function. We found the TbLOK1 protein located in discrete patches in the mitochondrial outer membrane. Knock-down of TbLOK1 in procyclic trypanosomes caused the highly interconnected mitochondrial structure to collapse, forming an unbranched tubule remarkably similar to the streamlined organelle seen in the bloodstream form. Following RNAi, defects in mitochondrial respiration, inner membrane potential and mitochondrial transcription were observed. At later times following TbLOK1 depletion, kDNA was lost and a more drastic alteration in mitochondrial structure was found. Our results demonstrate the close relationship between organelle structure and function in trypanosomes.
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Affiliation(s)
- Megan L Povelones
- Department of Biological Chemistry, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
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34
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Tschudi C, Shi H, Franklin JB, Ullu E. Small interfering RNA-producing loci in the ancient parasitic eukaryote Trypanosoma brucei. BMC Genomics 2012; 13:427. [PMID: 22925482 PMCID: PMC3447711 DOI: 10.1186/1471-2164-13-427] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2012] [Accepted: 08/24/2012] [Indexed: 01/24/2023] Open
Abstract
Background At the core of the RNA interference (RNAi) pathway in Trypanosoma brucei is a single Argonaute protein, TbAGO1, with an established role in controlling retroposon and repeat transcripts. Recent evidence from higher eukaryotes suggests that a variety of genomic sequences with the potential to produce double-stranded RNA are sources for small interfering RNAs (siRNAs). Results To test whether such endogenous siRNAs are present in T. brucei and to probe the individual role of the two Dicer-like enzymes, we affinity purified TbAGO1 from wild-type procyclic trypanosomes, as well as from cells deficient in the cytoplasmic (TbDCL1) or nuclear (TbDCL2) Dicer, and subjected the bound RNAs to Illumina high-throughput sequencing. In wild-type cells the majority of reads originated from two classes of retroposons. We also considerably expanded the repertoire of trypanosome siRNAs to encompass a family of 147-bp satellite-like repeats, many of the regions where RNA polymerase II transcription converges, large inverted repeats and two pseudogenes. Production of these newly described siRNAs is strictly dependent on the nuclear DCL2. Notably, our data indicate that putative centromeric regions, excluding the CIR147 repeats, are not a significant source for endogenous siRNAs. Conclusions Our data suggest that endogenous RNAi targets may be as evolutionarily old as the mechanism itself.
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Affiliation(s)
- Christian Tschudi
- Department of Internal Medicine, School of Medicine, Yale University, New Haven, CT 06536, USA
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35
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Moraes Barros RR, Marini MM, Antônio CR, Cortez DR, Miyake AM, Lima FM, Ruiz JC, Bartholomeu DC, Chiurillo MA, Ramirez JL, da Silveira JF. Anatomy and evolution of telomeric and subtelomeric regions in the human protozoan parasite Trypanosoma cruzi. BMC Genomics 2012; 13:229. [PMID: 22681854 PMCID: PMC3418195 DOI: 10.1186/1471-2164-13-229] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2011] [Accepted: 06/08/2012] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND The subtelomeres of many protozoa are highly enriched in genes with roles in niche adaptation. T. cruzi trypomastigotes express surface proteins from Trans-Sialidase (TS) and Dispersed Gene Family-1 (DGF-1) superfamilies which are implicated in host cell invasion. Single populations of T. cruzi may express different antigenic forms of TSs. Analysis of TS genes located at the telomeres suggests that chromosome ends could have been the sites where new TS variants were generated. The aim of this study is to characterize telomeric and subtelomeric regions of T. cruzi available in TriTrypDB and connect the sequences of telomeres to T. cruzi working draft sequence. RESULTS We first identified contigs carrying the telomeric repeat (TTAGGG). Of 49 contigs identified, 45 have telomeric repeats at one end, whereas in four contigs the repeats are located internally. All contigs display a conserved telomeric junction sequence adjacent to the hexamer repeats which represents a signature of T. cruzi chromosome ends. We found that 40 telomeric contigs are located on T. cruzi chromosome-sized scaffolds. In addition, we were able to map several telomeric ends to the chromosomal bands separated by pulsed-field gel electrophoresis.The subtelomeric sequence structure varies widely, mainly as a result of large differences in the relative abundance and organization of genes encoding surface proteins (TS and DGF-1), retrotransposon hot spot genes (RHS), retrotransposon elements, RNA-helicase and N-acetyltransferase genes. While the subtelomeric regions are enriched in pseudogenes, they also contain complete gene sequences matching both known and unknown expressed genes, indicating that these regions do not consist of nonfunctional DNA but are instead functional parts of the expressed genome. The size of the subtelomeric regions varies from 5 to 182 kb; the smaller of these regions could have been generated by a recent chromosome breakage and telomere healing event. CONCLUSIONS The lack of synteny in the subtelomeric regions suggests that genes located in these regions are subject to recombination, which increases their variability, even among homologous chromosomes. The presence of typical subtelomeric genes can increase the chance of homologous recombination mechanisms or microhomology-mediated end joining, which may use these regions for the pairing and recombination of free ends.
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Affiliation(s)
- Roberto R Moraes Barros
- Departamento de Microbiologia, Imunologia e Parasitologia Escola Paulista de Medicina, UNIFESP, São Paulo, SP, Brazil
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36
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Proteomic analysis of Trypanosoma cruzi epimastigotes subjected to heat shock. J Biomed Biotechnol 2012; 2012:902803. [PMID: 22287837 PMCID: PMC3263753 DOI: 10.1155/2012/902803] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2011] [Revised: 08/31/2011] [Accepted: 09/08/2011] [Indexed: 02/06/2023] Open
Abstract
Trypanosoma cruzi is exposed to sudden temperature changes during its life cycle. Adaptation to these variations is crucial for parasite survival, reproduction, and transmission. Some of these conditions may change the pattern of genetic expression of proteins involved in homeostasis in the course of stress treatment. In the present study, the proteome of T. cruzi epimastigotes subjected to heat shock and epimastigotes grow normally was compared by two-dimensional gel electrophoresis followed by mass spectrometry for protein identification. Twenty-four spots differing in abundance were identified. Of the twenty-four changed spots, nineteen showed a greater intensity and five a lower intensity relative to the control. Several functional categories of the identified proteins were determined: metabolism, cell defense, hypothetical proteins, protein fate, protein synthesis, cellular transport, and cell cycle. Proteins involved in the interaction with the cellular environment were also identified, and the implications of these changes are discussed.
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Grynberg P, Passos-Silva DG, Mourão MDM, Hirata Jr R, Macedo AM, Machado CR, Bartholomeu DC, Franco GR. Trypanosoma cruzi gene expression in response to gamma radiation. PLoS One 2012; 7:e29596. [PMID: 22247781 PMCID: PMC3256153 DOI: 10.1371/journal.pone.0029596] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2011] [Accepted: 11/30/2011] [Indexed: 01/19/2023] Open
Abstract
Trypanosoma cruzi is an organism highly resistant to ionizing radiation. Following a dose of 500 Gy of gamma radiation, the fragmented genomic DNA is gradually reconstructed and the pattern of chromosomal bands is restored in less than 48 hours. Cell growth arrests after irradiation but, while DNA is completely fragmented, RNA maintains its integrity. In this work we compared the transcriptional profiles of irradiated and non-irradiated epimastigotes at different time points after irradiation using microarray. In total, 273 genes were differentially expressed; from these, 160 were up-regulated and 113 down-regulated. We found that genes with predicted functions are the most prevalent in the down-regulated gene category. Translation and protein metabolic processes, as well as generation of precursor of metabolites and energy pathways were affected. In contrast, the up-regulated category was mainly composed of obsolete sequences (which included some genes of the kinetoplast DNA), genes coding for hypothetical proteins, and Retrotransposon Hot Spot genes. Finally, the tyrosyl-DNA phosphodiesterase 1, a gene involved in double-strand DNA break repair process, was up-regulated. Our study demonstrated the peculiar response to ionizing radiation, raising questions about how this organism changes its gene expression to manage such a harmful stress.
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Affiliation(s)
- Priscila Grynberg
- Departamento de Bioquímica e Imunologia, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Danielle Gomes Passos-Silva
- Departamento de Bioquímica e Imunologia, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Marina de Moraes Mourão
- Grupo de Genômica e Biologia Computacional, Centro de Pesquisas René Rachou, Fundação Oswaldo Cruz, Belo Horizonte, Minas Gerais, Brazil
- Instituto Nacional de Ciência e Tecnologia em Doenças Tropicais, Centro de Pesquisas René Rachou, Fundação Oswaldo Cruz, Belo Horizonte, Minas Gerais, Brazil
| | - Roberto Hirata Jr
- Instituto de Matemática e Estatística, Universidade de São Paulo, São Paulo, São Paulo, Brazil
| | - Andrea Mara Macedo
- Departamento de Bioquímica e Imunologia, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Carlos Renato Machado
- Departamento de Bioquímica e Imunologia, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | | | - Glória Regina Franco
- Departamento de Bioquímica e Imunologia, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
- * E-mail:
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Pseudogene-derived small interference RNAs regulate gene expression in African Trypanosoma brucei. Proc Natl Acad Sci U S A 2011; 108:8345-50. [PMID: 21531904 DOI: 10.1073/pnas.1103894108] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Pseudogenes have been shown to acquire unique regulatory roles from more and more organisms. We report the observation of a cluster of siRNAs derived from pseudogenes of African Trypanosoma brucei using high through-put analysis. We show that these pseudogene-derived siRNAs suppress gene expression through RNA interference. The discovery that siRNAs may originate from pseudogenes and regulate gene expression in a unicellular eukaryote provides insights into the functional roles of pseudogenes and into the origin of noncoding small RNAs.
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Grisard EC, Stoco PH, Wagner G, Sincero TCM, Rotava G, Rodrigues JB, Snoeijer CQ, Koerich LB, Sperandio MM, Bayer-Santos E, Fragoso SP, Goldenberg S, Triana O, Vallejo GA, Tyler KM, Dávila AMR, Steindel M. Transcriptomic analyses of the avirulent protozoan parasite Trypanosoma rangeli. Mol Biochem Parasitol 2010; 174:18-25. [PMID: 20600354 DOI: 10.1016/j.molbiopara.2010.06.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2010] [Revised: 05/24/2010] [Accepted: 06/11/2010] [Indexed: 11/25/2022]
Abstract
Two species of the genus Trypanosoma infective to humans have been extensively studied at a cell and molecular level, but study of the third, Trypanosoma rangeli, remains in relative infancy. T. rangeli is non-pathogenic, but is frequently mistaken for the related Chagas disease agent Trypanosoma cruzi with which it shares vectors, hosts, significant antigenicity and a sympatric distribution over a wide geographical area. In this study, we present the T. rangeli gene expression profile as determined by the generation of ESTs (Expressed Sequence Tags) and ORESTES (Open Reading Frame ESTs). A total of 4208 unique high quality sequences were analyzed, composed from epimastigote and trypomastigote forms of SC-58 and Choachí strains, representing the two major phylogenetic lineages of this species. Comparative analyses with T. cruzi and other parasitic kinetoplastid species allowed the assignment of putative biological functions to most of the sequences generated and the establishment of an annotated T. rangeli gene expression database. Even though T. rangeli is apathogenic to mammals, genes associated with virulence in other pathogenic kinetoplastids were found. Transposable elements and genes associated mitochondrial gene expression, specifically RNA editing components, are also described for the first time. Our studies confirm the close phylogenetic relationship between T. cruzi and T. rangeli and enable us to make an estimate for the size of the T. rangeli genome repertoire ( approximately 8500 genes).
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Affiliation(s)
- Edmundo C Grisard
- Universidade Federal de Santa Catarina, Florianópolis 88040-970, SC, Brazil.
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40
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Thomas MC, Macias F, Alonso C, López MC. The biology and evolution of transposable elements in parasites. Trends Parasitol 2010; 26:350-62. [PMID: 20444649 DOI: 10.1016/j.pt.2010.04.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2009] [Revised: 03/30/2010] [Accepted: 04/01/2010] [Indexed: 12/19/2022]
Abstract
Transposable elements (TEs) are dynamic elements that can reshape host genomes by generating rearrangements with the potential to create or disrupt genes, to shuffle existing genes, and to modulate their patterns of expression. In the genomes of parasites that infect mammals several TEs have been identified that probably have been maintained throughout evolution due to their contribution to gene function and regulation of gene expression. This review addresses how TEs are organized, how they colonize the genomes of mammalian parasites, the functional role these elements play in parasite biology, and the interactions between these elements and the parasite genome.
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Affiliation(s)
- M Carmen Thomas
- Departamento de Biología Molecular, Instituto de Parasitología y Biomedicina López Neyra - CSIC, Parque Tecnológico de Ciencias de la Salud, 18100 Granada, Spain
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41
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Immunobiology of African trypanosomes: need of alternative interventions. J Biomed Biotechnol 2010; 2010:389153. [PMID: 20182644 PMCID: PMC2826769 DOI: 10.1155/2010/389153] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2009] [Revised: 10/29/2009] [Accepted: 12/23/2009] [Indexed: 02/08/2023] Open
Abstract
Trypanosomiasis is one of the major parasitic diseases for which control is still far from reality. The vaccination approaches by using dominant surface proteins have not been successful, mainly due to antigenic variation of the parasite surface coat. On the other hand, the chemotherapeutic drugs in current use for the treatment of this disease are toxic and problems of resistance are increasing (see Kennedy (2004) and Legros et al. (2002)). Therefore, alternative approaches in both treatment and vaccination against trypanosomiasis are needed at this time. To be able to design and develop such alternatives, the biology of this parasite and the host response against the pathogen need to be studied. These two aspects of this disease with few examples of alternative approaches are discussed here.
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Nakayasu ES, Gaynor MR, Sobreira TJP, Ross JA, Almeida IC. Phosphoproteomic analysis of the human pathogen Trypanosoma cruzi at the epimastigote stage. Proteomics 2009; 9:3489-506. [PMID: 19579231 DOI: 10.1002/pmic.200800874] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Trypanosoma cruzi is the etiologic agent of Chagas disease, which affects millions of people in Latin America and has become a public health concern in the United States and areas of Europe. The possibility that kinase inhibitors represent novel anti-parasitic agents is currently being explored. However, fundamental understanding of the cell-signaling networks requires the detailed analysis of the involved phosphorylated proteins. Here, we have performed a comprehensive MS-based phosphorylation mapping of phosphoproteins from T. cruzi epimastigote forms. Our LC-MS/MS, dual-stage fragmentation, and multistage activation analysis has identified 237 phosphopeptides from 119 distinct proteins. Furthermore, 220 phosphorylation sites were unambiguously mapped: 148 on serine, 57 on threonine, and 8 on tyrosine. In addition, immunoprecipitation and Western blotting analysis confirmed the presence of at least seven tyrosine-phosphorylated proteins in T. cruzi. The identified phosphoproteins were subjected to Gene Ontology, InterPro, and BLAST analysis, and categorized based on their role in cell structure, motility, transportation, metabolism, pathogenesis, DNA/RNA/protein turnover, and signaling. Taken together, our phosphoproteomic data provide new insights into the molecular mechanisms governed by protein kinases and phosphatases in T. cruzi. We discuss the potential roles of the identified phosphoproteins in parasite physiology and drug development.
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Affiliation(s)
- Ernesto S Nakayasu
- The Border Biomedical Research Center, Department of Biological Sciences, University of Texas at El Paso, El Paso, TX 79968, USA
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Petersen G, Seberg O. StowawayMITEs inHordeum(Poaceae): evolutionary history, ancestral elements and classification. Cladistics 2009; 25:198-208. [DOI: 10.1111/j.1096-0031.2008.00245.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
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Abstract
It is currently unclear if there are modified DNA bases in Trypanosoma brucei other than J-base. We identify herein a cytosine-5 DNA methyltransferase gene and report the presence and location of 5-methylcytosine in genomic DNA. Our data demonstrate that African trypanosomes contain a functional cytosine DNA methylation pathway.
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Kloc A, Martienssen R. RNAi, heterochromatin and the cell cycle. Trends Genet 2008; 24:511-7. [PMID: 18778867 DOI: 10.1016/j.tig.2008.08.002] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2008] [Revised: 08/04/2008] [Accepted: 08/05/2008] [Indexed: 01/15/2023]
Abstract
For many decades after its initial characterization, heterochromatin was considered to be transcriptionally inert, but newer work indicates that this highly condensed chromosomal material is transcribed, and rapidly silenced, by an orchestrated sequence of events directed by RNA interference (RNAi). Recent studies shed light on the timely assembly and inheritance of heterochromatin within a short period during the cell cycle, thereby providing an explanation for how 'silent' heterochromatin can be transcribed during the S phase of the cell cycle. Together, these findings suggest a model of RNAi-directed epigenetic inheritance.
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Affiliation(s)
- Anna Kloc
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
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Durand-Dubief M, Absalon S, Menzer L, Ngwabyt S, Ersfeld K, Bastin P. The Argonaute protein TbAGO1 contributes to large and mini-chromosome segregation and is required for control of RIME retroposons and RHS pseudogene-associated transcripts. Mol Biochem Parasitol 2007; 156:144-53. [PMID: 17822785 DOI: 10.1016/j.molbiopara.2007.07.016] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2007] [Revised: 07/15/2007] [Accepted: 07/24/2007] [Indexed: 12/11/2022]
Abstract
The protist Trypanosoma brucei possesses a single Argonaute gene called TbAGO1 that is necessary for RNAi silencing. We previously showed that in strain 427, TbAGO1 knock-out leads to a slow growth phenotype and to chromosome segregation defects. Here we report that the slow growth phenotype is linked to defects in segregation of both large and mini-chromosome populations, with large chromosomes being the most affected. These phenotypes are completely reversed upon inducible re-expression of TbAGO1 fused to GFP, demonstrating their link with TbAGO1. Trypanosomes that do not express TbAGO1 show a general increase in the abundance of transcripts derived from the short retroposon RIME (Ribosomal Interspersed Mobile Element). Supplementary large RIME transcripts emerge in the absence of RNAi, a phenomenon coupled to the disappearance of short transcripts. These fluctuations are reversed by inducible expression of GFP::TbAGO1. Furthermore, we use a combination of Northern blots, RT-PCR and sequencing to reveal that RNAi controls expression of transcripts derived from RHS (Retrotransposon Hot Spot) pseudogenes (RHS genes with retro-element(s) integrated within their coding sequence). Absence of RNAi also leads to an increase of steady-state transcripts from regular RHS genes (those without retro-element), indicating a role for pseudogene in control of gene expression. However, analysis of retroposon abundance and arrangement in the genome of multiple clonal cell lines of TbAGO1-/- failed to reveal movement of mobile elements despite the increased amounts of retroposon transcripts.
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Affiliation(s)
- Mickaël Durand-Dubief
- Régulation et Dynamique des Génomes, Muséum National d'Histoire Naturelle, INSERM & CNRS, 75005 Paris, France
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Souza RT, Santos MRM, Lima FM, El-Sayed NM, Myler PJ, Ruiz JC, da Silveira JF. New Trypanosoma cruzi repeated element that shows site specificity for insertion. EUKARYOTIC CELL 2007; 6:1228-38. [PMID: 17526721 PMCID: PMC1951114 DOI: 10.1128/ec.00036-07] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
A new family of site-specific repeated elements identified in Trypanosoma cruzi, which we named TcTREZO, is described here. TcTREZO appears to be a composite repeated element, since three subregions may be defined within it on the basis of sequence similarities with other T. cruzi sequences. Analysis of the distribution of TcTREZO in the genome clearly indicates that it displays site specificity for insertion. Most TcTREZO elements are flanked by conserved sequences. There is a highly conserved 68-bp sequence at the 5' end of the element and a sequence domain of approximately 500 bp without a well-defined borderline at the 3' end. Northern blot hybridization and reverse transcriptase PCR analyses showed that TcTREZO transcripts are expressed as oligo(A)-terminated transcripts whose length corresponds to the unit size of the element (1.6 kb). Transcripts of approximately 0.2 kb derived from a small part of TcTREZO are also detected in steady-state RNA. TcTREZO transcripts are unspliced and not translated. The copy number of TcTREZO sequences was estimated to be approximately 173 copies per haploid genome. TcTREZO appears to have been assembled by insertions of sequences into a progenitor element. Once associated with each other, these subunits were amplified as a new transposable element. TcTREZO shows site specificity for insertion, suggesting that a sequence-specific endonuclease could be responsible for its insertion at a unique site.
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Affiliation(s)
- Renata T Souza
- Department of Microbiology, Immunology and Parasitology, Escola Paulista de Medicina, UNIFESP, Rua Botucatu, São Paulo, Brazil
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Smith DF, Peacock CS, Cruz AK. Comparative genomics: from genotype to disease phenotype in the leishmaniases. Int J Parasitol 2007; 37:1173-86. [PMID: 17645880 PMCID: PMC2696322 DOI: 10.1016/j.ijpara.2007.05.015] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2007] [Revised: 05/18/2007] [Accepted: 05/21/2007] [Indexed: 11/29/2022]
Abstract
Recent progress in sequencing the genomes of several Leishmania species, causative agents of cutaneous, mucocutaneous and visceral leishmaniasis, is revealing unusual features of potential relevance to parasite virulence and pathogenesis in the host. While the genomes of Leishmania major, Leishmania braziliensis and Leishmania infantum are highly similar in content and organisation, species-specific genes and mechanisms distinguish one from another. In particular, the presence of retrotransposons and the components of a putative RNA interference machinery in L. braziliensis suggest the potential for both greater diversity and more tractable experimentation in this Leishmania Viannia species.
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Affiliation(s)
- Deborah F Smith
- Immunology and Infection Unit, Department of Biology/Hull York Medical School, University of York, Heslington, York YO10 5YW, UK.
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Mason-Gamer RJ. Multiple homoplasious insertions and deletions of a Triticeae (Poaceae) DNA transposon: a phylogenetic perspective. BMC Evol Biol 2007; 7:92. [PMID: 17570855 PMCID: PMC1925063 DOI: 10.1186/1471-2148-7-92] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2006] [Accepted: 06/14/2007] [Indexed: 11/13/2022] Open
Abstract
Background Stowaway elements are short, non-autonomous DNA transposons categorized as miniature inverted-repeat transposable elements (MITEs). The high MITE copy number in grass genomes suggests an active history of amplification and insertion, but ongoing MITE activity has only rarely been seen, and ongoing Stowaway activity has never been observed. Thus, a phylogenetic perspective on presence vs. absence of elements in an aligned data set can provide valuable historical insights into the dynamics of MITE acquisition and loss. Results A Stowaway-like element resides within the fourth intron of a β-amylase gene in representatives of five genera in the wheat tribe, Triticeae. Its presence vs. absence was examined with reference to the β-amylase gene tree topology, and in light of sequence comparisons of the β-amylase elements to Triticeae Stowaway elements in the Entrez nucleotide database. Among the sequences lacking the element, there are five distinct putative excision footprints (one widespread and four restricted to unrelated lineages) and two flanking deletions. The sequences that do contain elements are polyphyletic on the β-amylase tree, and their elements are divergent at the sequence level. The β-amylase elements do not form a monophyletic group relative to other Stowaway elements in Entrez; most are more similar to elements from other loci in other Triticeae genomes than they are to one another. Conclusion Combined, the phylogenetic distribution, sequence variation, and Entrez database comparisons indicate that a Stowaway-like element has undergone multiple deletions from and insertions into the same site in β-amylase intron 4 during the history of the tribe. The elements currently at the site represent multiple, distinct lineages that transcend generic boundaries. While patterns of Stowaway polymorphism across a phylogenetic data set do not allow evolutionary mechanisms to be inferred with certainty, they do provide insights into the dynamics of element evolution over an extended time scale. The historical perspective provided by a phylogenetic approach is complementary to the few studies in which ongoing MITE activity has been documented.
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Affiliation(s)
- Roberta J Mason-Gamer
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, Illinois, USA.
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Heras SR, López MC, Olivares M, Thomas MC. The L1Tc non-LTR retrotransposon of Trypanosoma cruzi contains an internal RNA-pol II-dependent promoter that strongly activates gene transcription and generates unspliced transcripts. Nucleic Acids Res 2007; 35:2199-214. [PMID: 17369274 PMCID: PMC1874656 DOI: 10.1093/nar/gkl1137] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
L1Tc is the best represented autonomous LINE of the Trypanosoma cruzi genome, throughout which several functional copies may exist. In this study, we show that the first 77 bp of L1Tc (Pr77) (also present in the T. cruzi non-autonomous retrotransposon NARTc, in the Trypanosoma brucei RIME/ingi elements, and in the T. cruzi, T. brucei and Leishmania major degenerate L1Tc/ingi-related elements [DIREs]) behave as a promoter element that activates gene transcription. The transcription rate promoted by Pr77 is 10–14-fold higher than that mediated by sequences located upstream from the T. cruzi tandemly repeated genes KMP11 and the GAPDH. The Pr77 promoter-derived mRNAs initiate at nucleotide +1 of L1Tc, are unspliced and translated. L1Tc transcripts show a moderate half life and are RNA pol II dependent. The presence of an internal promoter at the 5′ end of L1Tc favors the production of full-length L1Tc RNAs and reinforces the hypothesis that this mobile element may be naturally autonomous in its transposition.
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Affiliation(s)
| | - Manuel C. López
- *To whom correspondence should be addressed. +34 958 181 662+34 958 181 632 Correspondence may also be addressed to M. Carmen Thomas. +34 958 181 662+34 958 181
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