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1.
Genetics ; 227(1)2024 May 07.
Artículo en Inglés | MEDLINE | ID: mdl-38529759

RESUMEN

FungiDB (https://fungidb.org) serves as a valuable online resource that seamlessly integrates genomic and related large-scale data for a wide range of fungal and oomycete species. As an integral part of the VEuPathDB Bioinformatics Resource Center (https://veupathdb.org), FungiDB continually integrates both published and unpublished data addressing various aspects of fungal biology. Established in early 2011, the database has evolved to support 674 datasets. The datasets include over 300 genomes spanning various taxa (e.g. Ascomycota, Basidiomycota, Blastocladiomycota, Chytridiomycota, Mucoromycota, as well as Albuginales, Peronosporales, Pythiales, and Saprolegniales). In addition to genomic assemblies and annotation, over 300 extra datasets encompassing diverse information, such as expression and variation data, are also available. The resource also provides an intuitive web-based interface, facilitating comprehensive approaches to data mining and visualization. Users can test their hypotheses and navigate through omics-scale datasets using a built-in search strategy system. Moreover, FungiDB offers capabilities for private data analysis via the integrated VEuPathDB Galaxy platform. FungiDB also permits genome improvements by capturing expert knowledge through the User Comments system and the Apollo genome annotation editor for structural and functional gene curation. FungiDB facilitates data exploration and analysis and contributes to advancing research efforts by capturing expert knowledge for fungal and oomycete species.


Asunto(s)
Biología Computacional , Bases de Datos Genéticas , Hongos , Internet , Oomicetos , Oomicetos/genética , Hongos/genética , Biología Computacional/métodos , Genoma Fúngico , Genómica/métodos , Programas Informáticos
2.
Nucleic Acids Res ; 52(D1): D808-D816, 2024 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-37953350

RESUMEN

The Eukaryotic Pathogen, Vector and Host Informatics Resource (VEuPathDB, https://veupathdb.org) is a Bioinformatics Resource Center funded by the National Institutes of Health with additional funding from the Wellcome Trust. VEuPathDB supports >600 organisms that comprise invertebrate vectors, eukaryotic pathogens (protists and fungi) and relevant free-living or non-pathogenic species or hosts. Since 2004, VEuPathDB has analyzed omics data from the public domain using contemporary bioinformatic workflows, including orthology predictions via OrthoMCL, and integrated the analysis results with analysis tools, visualizations, and advanced search capabilities. The unique data mining platform coupled with >3000 pre-analyzed data sets facilitates the exploration of pertinent omics data in support of hypothesis driven research. Comparisons are easily made across data sets, data types and organisms. A Galaxy workspace offers the opportunity for the analysis of private large-scale datasets and for porting to VEuPathDB for comparisons with integrated data. The MapVEu tool provides a platform for exploration of spatially resolved data such as vector surveillance and insecticide resistance monitoring. To address the growing body of omics data and advances in laboratory techniques, VEuPathDB has added several new data types, searches and features, improved the Galaxy workspace environment, redesigned the MapVEu interface and updated the infrastructure to accommodate these changes.


Asunto(s)
Biología Computacional , Eucariontes , Animales , Biología Computacional/métodos , Invertebrados , Bases de Datos Factuales
3.
PLoS Negl Trop Dis ; 17(1): e0011058, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36656904

RESUMEN

Parasitic diseases caused by kinetoplastid parasites are a burden to public health throughout tropical and subtropical regions of the world. TriTrypDB (https://tritrypdb.org) is a free online resource for data mining of genomic and functional data from these kinetoplastid parasites and is part of the VEuPathDB Bioinformatics Resource Center (https://veupathdb.org). As of release 59, TriTrypDB hosts 83 kinetoplastid genomes, nine of which, including Trypanosoma brucei brucei TREU927, Trypanosoma cruzi CL Brener and Leishmania major Friedlin, undergo manual curation by integrating information from scientific publications, high-throughput assays and user submitted comments. TriTrypDB also integrates transcriptomic, proteomic, epigenomic, population-level and isolate data, functional information from genome-wide RNAi knock-down and fluorescent tagging, and results from automated bioinformatics analysis pipelines. TriTrypDB offers a user-friendly web interface embedded with a genome browser, search strategy system and bioinformatics tools to support custom in silico experiments that leverage integrated data. A Galaxy workspace enables users to analyze their private data (e.g., RNA-sequencing, variant calling, etc.) and explore their results privately in the context of publicly available information in the database. The recent addition of an annotation platform based on Apollo enables users to provide both functional and structural changes that will appear as 'community annotations' immediately and, pending curatorial review, will be integrated into the official genome annotation.


Asunto(s)
Kinetoplastida , Programas Informáticos , Interfaz Usuario-Computador , Proteómica , Genómica/métodos , Biología Computacional/métodos , Bases de Datos Genéticas , Internet
4.
Nucleic Acids Res ; 50(W1): W623-W632, 2022 07 05.
Artículo en Inglés | MEDLINE | ID: mdl-35552456

RESUMEN

The Orthology Benchmark Service (https://orthology.benchmarkservice.org) is the gold standard for orthology inference evaluation, supported and maintained by the Quest for Orthologs consortium. It is an essential resource to compare existing and new methods of orthology inference (the bedrock for many comparative genomics and phylogenetic analysis) over a standard dataset and through common procedures. The Quest for Orthologs Consortium is dedicated to maintaining the resource up to date, through regular updates of the Reference Proteomes and increasingly accessible data through the OpenEBench platform. For this update, we have added a new benchmark based on curated orthology assertion from the Vertebrate Gene Nomenclature Committee, and provided an example meta-analysis of the public predictions present on the platform.


Asunto(s)
Benchmarking , Genómica , Filogenia , Genómica/métodos , Proteoma
6.
Curr Opin Insect Sci ; 50: 100860, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-34864248

RESUMEN

VectorBase (VectorBase.org) is part of the VEuPathDB Bioinformatics Resource Center, providing free online access to multi-omics and population biology data, focusing on arthropod vectors and invertebrates of importance to human health. VectorBase includes genomics and functional genomics data from bed bugs, biting midges, body lice, kissing bugs, mites, mosquitoes, sand flies, ticks, tsetse flies, stable flies, house flies, fruit flies, and a snail intermediate host. Tools include the Search Strategy system and MapVEu, enabling users to interrogate and visualize diverse 'omics and population-level data using a graphical interface (no programming experience required). Users can also analyze their own private data, such as transcriptomic sequences, exploring their results in the context of other publicly-available information in the database. Help Desk: help@vectorbase.org.


Asunto(s)
Biología Computacional , Culicidae , Animales , Genómica , Humanos , Invertebrados/genética , Mosquitos Vectores
7.
Am J Trop Med Hyg ; 103(4): 1525-1533, 2020 10.
Artículo en Inglés | MEDLINE | ID: mdl-32700666

RESUMEN

Tororo, a district in Uganda with historically high malaria transmission intensity, has recently scaled up control interventions, including universal long-lasting insecticidal net distribution in 2013 and 2017, and sustained indoor residual spraying (IRS) of insecticide since December 2014. We describe the burden of malaria in Tororo 5 years following the initiation of IRS. We followed a cohort of 531 participants from 80 randomly selected households in Nagongera subcounty, Tororo district, from October 2017 to October 2019. Mosquitoes were collected every 2 weeks using CDC light traps in all rooms where participants slept, symptomatic malaria was identified by passive surveillance, and microscopic and submicroscopic parasitemia were measured every 4 weeks using active surveillance. Over the 2 years of follow-up, 15,780 female anopheline mosquitos were collected, the majority (98.0%) of which were Anopheles arabiensis. The daily human biting rate was 2.07, and the annual entomological inoculation rate was 0.43 infective bites/person/year. Only 38 episodes of malaria were diagnosed (incidence 0.04 episodes/person/year), and there were no cases of severe malaria or malarial deaths. The prevalence of microscopic parasitemia was 1.9%, and the combined prevalence of microscopic and submicroscopic parasitemia was 10.4%, each highest in children aged 5-15 years (3.3% and 14.0%, respectively). After 5 years of intensive vector control measures in Tororo, the burden of malaria was reduced to very low transmission levels. However, a significant proportion of the population remained parasitemic, primarily school-aged children with submicroscopic parasitemia, providing a potential reservoir for malaria transmission.


Asunto(s)
Anopheles/parasitología , Insecticidas/uso terapéutico , Malaria/epidemiología , Control de Mosquitos , Mosquitos Vectores/parasitología , Adolescente , Animales , Niño , Preescolar , Estudios de Cohortes , Femenino , Humanos , Incidencia , Malaria/parasitología , Malaria/prevención & control , Malaria/transmisión , Masculino , Parasitemia/epidemiología , Parasitemia/parasitología , Parasitemia/transmisión , Prevalencia , Uganda/epidemiología
8.
J Exp Med ; 217(3)2020 03 02.
Artículo en Inglés | MEDLINE | ID: mdl-31961916

RESUMEN

The ability of Toxoplasma gondii to inject the rhoptry kinase ROP16 into host cells results in the activation of the transcription factors STAT3 and STAT6, but it is unclear how these events impact infection. Here, parasites that inject Cre-recombinase with rhoptry proteins were used to distinguish infected macrophages from those only injected with parasite proteins. Transcriptional profiling revealed that injection of rhoptry proteins alone was sufficient to induce an M2 phenotype that is dependent on STAT3 and STAT6, but only infected cells displayed reduced expression of genes associated with antimicrobial activity and protective immunity. In vivo, the absence of STAT3 or STAT6 improved parasite control, while the loss of ROP16 resulted in a marked reduction in parasite numbers and heightened parasite-specific T cell responses. Thus, ROP16 is a virulence factor that can act in cis and trans to promote M2 programs and which limits the magnitude of parasite-specific T cell responses.


Asunto(s)
Proteínas Tirosina Quinasas/inmunología , Proteínas Protozoarias/inmunología , Linfocitos T/inmunología , Toxoplasma/inmunología , Factores de Virulencia/inmunología , Animales , Macrófagos/inmunología , Ratones , Ratones Endogámicos C57BL , Factor de Transcripción STAT3/inmunología , Factor de Transcripción STAT6/inmunología
9.
Methods Mol Biol ; 2071: 27-47, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-31758445

RESUMEN

ToxoDB is a free online resource that provides access to genomic and functional genomic data. All data is made available through an intuitive queryable interface that enables scientists to build in silico experiments and develop testable hypothesis. The resource contains 32 fully sequenced and annotated genomes, with genomic sequence from multiple strains available for variant detection and copy number variation analysis. In addition to genomic sequence data, ToxoDB contains numerous functional genomic datasets including microarray, RNAseq, proteomics, ChIP-seq, and phenotypic data. In addition, results from a number of whole-genome analyses are incorporated including mapping to orthology clusters which allows users to leverage phylogenetic relationships in their analyses. Integration of primary data is made possible through a private galaxy interface and custom export tools that allow users to interrogate their own results in the context of all other data in the database.


Asunto(s)
Biología Computacional/métodos , Genómica/métodos , Toxoplasma/genética , Toxoplasma/metabolismo , Secuenciación de Inmunoprecipitación de Cromatina , Estudio de Asociación del Genoma Completo , Proteómica/métodos
10.
Gates Open Res ; 3: 1661, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-32047873

RESUMEN

The concept of open data has been gaining traction as a mechanism to increase data use, ensure that data are preserved over time, and accelerate discovery. While epidemiology data sets are increasingly deposited in databases and repositories, barriers to access still remain. ClinEpiDB was constructed as an open-access online resource for clinical and epidemiologic studies by leveraging the extensive web toolkit and infrastructure of the Eukaryotic Pathogen Database Resources (EuPathDB; a collection of databases covering 170+ eukaryotic pathogens, relevant related species, and select hosts) combined with a unified semantic web framework. Here we present an intuitive point-and-click website that allows users to visualize and subset data directly in the ClinEpiDB browser and immediately explore potential associations. Supporting study documentation aids contextualization, and data can be downloaded for advanced analyses. By facilitating access and interrogation of high-quality, large-scale data sets, ClinEpiDB aims to spur collaboration and discovery that improves global health.

11.
mBio ; 9(5)2018 10 30.
Artículo en Inglés | MEDLINE | ID: mdl-30377279

RESUMEN

Toxoplasma gondii infects approximately 30% of the world's population, causing disease primarily during pregnancy and in individuals with weakened immune systems. Toxoplasma secretes and exports effector proteins that modulate the host during infection, and several of these proteins are processed by the Golgi-associated aspartyl protease 5 (ASP5). Here, we identify ASP5 substrates by selectively enriching N-terminally derived peptides from wild-type and Δasp5 parasites. We reveal more than 2,000 unique Toxoplasma N-terminal peptides, mapping to both natural N termini and protease cleavage sites. Several of these peptides mapped directly downstream of the characterized ASP5 cleavage site, arginine-arginine-leucine (RRL). We validate candidates as true ASP5 substrates, revealing they are not processed in parasites lacking ASP5 or in wild-type parasites following mutation of the motif from RRL to ARL. All identified ASP5 substrates are dense granule proteins, and interestingly, none appear to be exported, thus differing from the analogous system in related Plasmodium spp. Instead we show that the majority of substrates reside within the parasitophorous vacuole (PV), and its membrane (the PVM), including two kinases and one phosphatase. We show that genetic deletion of WNG2 leads to attenuation in a mouse model, suggesting that this putative kinase is a new virulence factor in Toxoplasma Collectively, these data constitute the first in-depth analyses of ASP5 substrates and shed new light on the role of ASP5 as a maturase of dense granule proteins during the Toxoplasma lytic cycle.IMPORTANCEToxoplasma gondii is one of the most successful human parasites. Central to its success is the arsenal of virulence proteins introduced into the infected host cell. Several of these virulence proteins require direct maturation by the aspartyl protease ASP5, and all require ASP5 for translocation into the host cell, yet the true number of ASP5 substrates and complete repertoire of effectors is currently unknown. Here we selectively enrich N-terminally derived peptides using Terminal Amine Isotopic Labeling of Substrates (TAILS) and use quantitative proteomics to reveal novel ASP5 substrates. We identify, using two different enrichment techniques, new ASP5 substrates and their specific cleavage sites. ASP5 substrates include two kinases and one phosphatase that reside at the host-parasite interface, which are important for infection.


Asunto(s)
Proteasas de Ácido Aspártico/metabolismo , Procesamiento Proteico-Postraduccional , Proteínas Protozoarias/metabolismo , Toxoplasma/enzimología , Toxoplasma/metabolismo , Proteasas de Ácido Aspártico/genética , Células Cultivadas , Fibroblastos/parasitología , Eliminación de Gen , Humanos , Membranas Intracelulares/metabolismo , Proteínas Protozoarias/genética , Toxoplasma/genética , Vacuolas/metabolismo , Vacuolas/parasitología
12.
Artículo en Inglés | MEDLINE | ID: mdl-30345257

RESUMEN

Toxoplasma gondii, an Apicomplexan parasite, causes significant morbidity and mortality, including severe disease in immunocompromised hosts and devastating congenital disease, with no effective treatment for the bradyzoite stage. To address this, we used the Tropical Disease Research database, crystallography, molecular modeling, and antisense to identify and characterize a range of potential therapeutic targets for toxoplasmosis. Phosphoglycerate mutase II (PGMII), nucleoside diphosphate kinase (NDK), ribulose phosphate 3-epimerase (RPE), ribose-5-phosphate isomerase (RPI), and ornithine aminotransferase (OAT) were structurally characterized. Crystallography revealed insights into the overall structure, protein oligomeric states and molecular details of active sites important for ligand recognition. Literature and molecular modeling suggested potential inhibitors and druggability. The targets were further studied with vivoPMO to interrupt enzyme synthesis, identifying the targets as potentially important to parasitic replication and, therefore, of therapeutic interest. Targeted vivoPMO resulted in statistically significant perturbation of parasite replication without concomitant host cell toxicity, consistent with a previous CRISPR/Cas9 screen showing PGM, RPE, and RPI contribute to parasite fitness. PGM, RPE, and RPI have the greatest promise for affecting replication in tachyzoites. These targets are shared between other medically important parasites and may have wider therapeutic potential.


Asunto(s)
Enzimas/metabolismo , Proteínas Protozoarias/antagonistas & inhibidores , Toxoplasma/enzimología , Toxoplasma/fisiología , Cristalografía por Rayos X , Enzimas/química , Enzimas/genética , Técnicas de Silenciamiento del Gen , Modelos Moleculares , Conformación Proteica , Proteínas Protozoarias/química , Proteínas Protozoarias/genética , Toxoplasma/crecimiento & desarrollo
13.
Int J Parasitol ; 48(12): 955-968, 2018 10.
Artículo en Inglés | MEDLINE | ID: mdl-30176233

RESUMEN

Toxoplasma gondii can grow and replicate using either glucose or glutamine as the major carbon source. Here, we have studied the essentiality of glycolysis in the tachyzoite and bradyzoite stages of T. gondii, using transgenic parasites that lack a functional hexokinase gene (Δhk) in RH (Type-1) and Prugniaud (Type-II) strain parasites. Tachyzoite stage Δhk parasites exhibit a fitness defect similar to that reported previously for the major glucose transporter mutant, and remain virulent in mice. However, although Prugniaud strain Δhk tachyzoites were capable of transforming into bradyzoites in vitro, they were severely compromised in their ability to make mature bradyzoite cysts in the brain tissue of mice. Isotopic labelling studies reveal that glucose-deprived tacyzoites utilise glutamine to replenish glycolytic and pentose phosphate pathway intermediates via gluconeogenesis. Interestingly, while glutamine-deprived intracellular Δhk tachyzoites continued to replicate, extracellular parasites were unable to efficiently invade host cells. Further, studies on mutant tachyzoites lacking a functional phosphoenolpyruvate carboxykinase (Δpepck1) revealed that glutaminolysis is the sole source of gluconeogenic flux in glucose-deprived parasites. In addition, glutaminolysis is essential for sustaining oxidative phosphorylation in Δhk parasites, while wild type (wt) and Δpepck1 parasites can obtain ATP from either glycolysis or oxidative phosphorylation. This study provides insights into the role of nutrient metabolism during asexual propagation and development of T. gondii, and validates the versatile nature of central carbon and energy metabolism in this parasite.


Asunto(s)
Carbono/metabolismo , Glucólisis , Toxoplasma/crecimiento & desarrollo , Toxoplasma/metabolismo , Adenosina Trifosfato/biosíntesis , Animales , Encéfalo/parasitología , Modelos Animales de Enfermedad , Eliminación de Gen , Gluconeogénesis , Glutamina/metabolismo , Hexoquinasa/deficiencia , Análisis de Flujos Metabólicos , Ratones , Fosforilación Oxidativa , Fosfoenolpiruvato Carboxiquinasa (ATP)/deficiencia , Toxoplasmosis/parasitología , Toxoplasmosis/patología , Virulencia
14.
J Fungi (Basel) ; 4(1)2018 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-30152809

RESUMEN

FungiDB (fungidb.org) is a free online resource for data mining and functional genomics analysis for fungal and oomycete species. FungiDB is part of the Eukaryotic Pathogen Genomics Database Resource (EuPathDB, eupathdb.org) platform that integrates genomic, transcriptomic, proteomic, and phenotypic datasets, and other types of data for pathogenic and nonpathogenic, free-living and parasitic organisms. FungiDB is one of the largest EuPathDB databases containing nearly 100 genomes obtained from GenBank, Aspergillus Genome Database (AspGD), The Broad Institute, Joint Genome Institute (JGI), Ensembl, and other sources. FungiDB offers a user-friendly web interface with embedded bioinformatics tools that support custom in silico experiments that leverage FungiDB-integrated data. In addition, a Galaxy-based workspace enables users to generate custom pipelines for large-scale data analysis (e.g., RNA-Seq, variant calling, etc.). This review provides an introduction to the FungiDB resources and focuses on available features, tools, and queries and how they can be used to mine data across a diverse range of integrated FungiDB datasets and records.

15.
Methods Mol Biol ; 1757: 69-113, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29761457

RESUMEN

Fighting infections and developing novel drugs and vaccines requires advanced knowledge of pathogen's biology. Readily accessible genomic, functional genomic, and population data aids biological and translational discovery. The Eukaryotic Pathogen Database Resources ( http://eupathdb.org ) are data mining resources that support hypothesis driven research by facilitating the discovery of meaningful biological relationships from large volumes of data. The resource encompasses 13 sites that support over 170 species including pathogenic protists, oomycetes, and fungi as well as evolutionarily related nonpathogenic species. EuPathDB integrates preanalyzed data with advanced search capabilities, data visualization, analysis tools and a comprehensive record system in a graphical interface that does not require prior computational skills. This chapter describes guiding concepts common across EuPathDB sites and illustrates the powerful data mining capabilities of some of the available tools and features.


Asunto(s)
Bases de Datos Genéticas , Genómica , Parásitos/genética , Animales , Biología Computacional/métodos , Minería de Datos , Células Eucariotas , Genoma de Protozoos , Genómica/métodos , Redes y Vías Metabólicas , Parásitos/metabolismo , Proteómica/métodos , Programas Informáticos , Transcriptoma , Interfaz Usuario-Computador , Navegador Web
16.
Nucleic Acids Res ; 46(D1): D684-D691, 2018 01 04.
Artículo en Inglés | MEDLINE | ID: mdl-29106667

RESUMEN

MicrobiomeDB (http://microbiomeDB.org) is a data discovery and analysis platform that empowers researchers to fully leverage experimental variables to interrogate microbiome datasets. MicrobiomeDB was developed in collaboration with the Eukaryotic Pathogens Bioinformatics Resource Center (http://EuPathDB.org) and leverages the infrastructure and user interface of EuPathDB, which allows users to construct in silico experiments using an intuitive graphical 'strategy' approach. The current release of the database integrates microbial census data with sample details for nearly 14 000 samples originating from human, animal and environmental sources, including over 9000 samples from healthy human subjects in the Human Microbiome Project (http://portal.ihmpdcc.org/). Query results can be statistically analyzed and graphically visualized via interactive web applications launched directly in the browser, providing insight into microbial community diversity and allowing users to identify taxa associated with any experimental covariate.


Asunto(s)
Minería de Datos/métodos , Bases de Datos Genéticas , Microbiota , Biología de Sistemas , Animales , Simulación por Computador , Conjuntos de Datos como Asunto , Microbiología Ambiental , Variación Genética , Humanos , Internet , Aplicaciones Móviles , Interfaz Usuario-Computador , Flujo de Trabajo
17.
Nucleic Acids Res ; 45(D1): D581-D591, 2017 01 04.
Artículo en Inglés | MEDLINE | ID: mdl-27903906

RESUMEN

The Eukaryotic Pathogen Genomics Database Resource (EuPathDB, http://eupathdb.org) is a collection of databases covering 170+ eukaryotic pathogens (protists & fungi), along with relevant free-living and non-pathogenic species, and select pathogen hosts. To facilitate the discovery of meaningful biological relationships, the databases couple preconfigured searches with visualization and analysis tools for comprehensive data mining via intuitive graphical interfaces and APIs. All data are analyzed with the same workflows, including creation of gene orthology profiles, so data are easily compared across data sets, data types and organisms. EuPathDB is updated with numerous new analysis tools, features, data sets and data types. New tools include GO, metabolic pathway and word enrichment analyses plus an online workspace for analysis of personal, non-public, large-scale data. Expanded data content is mostly genomic and functional genomic data while new data types include protein microarray, metabolic pathways, compounds, quantitative proteomics, copy number variation, and polysomal transcriptomics. New features include consistent categorization of searches, data sets and genome browser tracks; redesigned gene pages; effective integration of alternative transcripts; and a EuPathDB Galaxy instance for private analyses of a user's data. Forthcoming upgrades include user workspaces for private integration of data with existing EuPathDB data and improved integration and presentation of host-pathogen interactions.


Asunto(s)
Bases de Datos Genéticas , Eucariontes , Genómica/métodos , Interacciones Huésped-Patógeno/genética , Metagenoma , Metagenómica/métodos , Programas Informáticos , Biología Computacional/métodos , Variaciones en el Número de Copia de ADN , Perfilación de la Expresión Génica , Proteómica , Navegador Web
18.
Proc Natl Acad Sci U S A ; 113(41): 11567-11572, 2016 10 11.
Artículo en Inglés | MEDLINE | ID: mdl-27663739

RESUMEN

Toxoplasma gondii is an intracellular parasite that causes disseminated infections in fetuses and immunocompromised individuals. Although gene regulation is important for parasite differentiation and pathogenesis, little is known about protein organization in the nucleus. Here we show that the fucose-binding Aleuria aurantia lectin (AAL) binds to numerous punctate structures in the nuclei of tachyzoites, bradyzoites, and sporozoites but not oocysts. AAL also binds to Hammondia and Neospora nuclei but not to more distantly related apicomplexans. Analyses of the AAL-enriched fraction indicate that AAL binds O-linked fucose added to Ser/Thr residues present in or adjacent to Ser-rich domains (SRDs). Sixty-nine Ser-rich proteins were reproducibly enriched with AAL, including nucleoporins, mRNA-processing enzymes, and cell-signaling proteins. Two endogenous SRDs-containing proteins and an SRD-YFP fusion localize with AAL to the nuclear membrane. Superresolution microscopy showed that the majority of the AAL signal localizes in proximity to nuclear pore complexes. Host cells modify secreted proteins with O-fucose; here we describe the O-fucosylation pathway in the nucleocytosol of a eukaryote. Furthermore, these results suggest O-fucosylation is a mechanism by which proteins involved in gene expression accumulate near the NPC.


Asunto(s)
Fucosa/metabolismo , Poro Nuclear/metabolismo , Proteínas Protozoarias/metabolismo , Toxoplasma/metabolismo , Secuencia de Aminoácidos , Animales , Ciclo Celular , Línea Celular , Glicoproteínas/química , Glicoproteínas/metabolismo , Glicosilación , Humanos , Lectinas/metabolismo , Ratones , Membrana Nuclear/metabolismo , Polisacáridos/metabolismo , Dominios Proteicos , Proteínas Protozoarias/química , Especificidad de la Especie
19.
Nat Commun ; 7: 10147, 2016 Jan 07.
Artículo en Inglés | MEDLINE | ID: mdl-26738725

RESUMEN

Toxoplasma gondii is among the most prevalent parasites worldwide, infecting many wild and domestic animals and causing zoonotic infections in humans. T. gondii differs substantially in its broad distribution from closely related parasites that typically have narrow, specialized host ranges. To elucidate the genetic basis for these differences, we compared the genomes of 62 globally distributed T. gondii isolates to several closely related coccidian parasites. Our findings reveal that tandem amplification and diversification of secretory pathogenesis determinants is the primary feature that distinguishes the closely related genomes of these biologically diverse parasites. We further show that the unusual population structure of T. gondii is characterized by clade-specific inheritance of large conserved haploblocks that are significantly enriched in tandemly clustered secretory pathogenesis determinants. The shared inheritance of these conserved haploblocks, which show a different ancestry than the genome as a whole, may thus influence transmission, host range and pathogenicity.


Asunto(s)
Genoma de Protozoos , Toxoplasma/genética , Toxoplasma/patogenicidad , Secuencia Conservada , ADN Protozoario/genética , Regulación de la Expresión Génica/fisiología , Filogenia , Polimorfismo de Nucleótido Simple , Proteínas Protozoarias/genética , Proteínas Protozoarias/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Sintenía , Virulencia
20.
J Biol Chem ; 291(8): 3725-46, 2016 Feb 19.
Artículo en Inglés | MEDLINE | ID: mdl-26694607

RESUMEN

The protozoan parasite Toxoplasma gondii develops within a parasitophorous vacuole (PV) in mammalian cells, where it scavenges cholesterol. When cholesterol is present in excess in its environment, the parasite expulses this lipid into the PV or esterifies it for storage in lipid bodies. Here, we characterized a unique T. gondii homologue of mammalian lecithin:cholesterol acyltransferase (LCAT), a key enzyme that produces cholesteryl esters via transfer of acyl groups from phospholipids to the 3-OH of free cholesterol, leading to the removal of excess cholesterol from tissues. TgLCAT contains a motif characteristic of serine lipases "AHSLG" and the catalytic triad consisting of serine, aspartate, and histidine (SDH) from LCAT enzymes. TgLCAT is secreted by the parasite, but unlike other LCAT enzymes it is cleaved into two proteolytic fragments that share the residues of the catalytic triad and need to be reassembled to reconstitute enzymatic activity. TgLCAT uses phosphatidylcholine as substrate to form lysophosphatidylcholine that has the potential to disrupt membranes. The released fatty acid is transferred to cholesterol, but with a lower transesterification activity than mammalian LCAT. TgLCAT is stored in a subpopulation of dense granule secretory organelles, and following secretion, it localizes to the PV and parasite plasma membrane. LCAT-null parasites have impaired growth in vitro, reduced virulence in animals, and exhibit delays in egress from host cells. Parasites overexpressing LCAT show increased virulence and faster egress. These observations demonstrate that TgLCAT influences the outcome of an infection, presumably by facilitating replication and egress depending on the developmental stage of the parasite.


Asunto(s)
Fosfatidilcolina-Esterol O-Aciltransferasa/metabolismo , Proteínas Protozoarias/metabolismo , Toxoplasma/enzimología , Toxoplasma/patogenicidad , Toxoplasmosis/enzimología , Dominio Catalítico , Línea Celular , Humanos , Fosfatidilcolina-Esterol O-Aciltransferasa/química , Fosfatidilcolina-Esterol O-Aciltransferasa/genética , Proteínas Protozoarias/química , Proteínas Protozoarias/genética , Toxoplasma/genética , Toxoplasmosis/genética , Toxoplasmosis/patología
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