Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 39
Filtrar
Más filtros

Intervalo de año de publicación
1.
PLoS Pathog ; 19(3): e1011260, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36972292

RESUMEN

Leprosy, caused by Mycobacterium leprae, rarely affects children younger than 5 years. Here, we studied a multiplex leprosy family that included monozygotic twins aged 22 months suffering from paucibacillary leprosy. Whole genome sequencing identified three amino acid mutations previously associated with Crohn's disease and Parkinson's disease as candidate variants for early onset leprosy: LRRK2 N551K, R1398H and NOD2 R702W. In genome-edited macrophages, we demonstrated that cells expressing the LRRK2 mutations displayed reduced apoptosis activity following mycobacterial challenge independently of NOD2. However, employing co-immunoprecipitation and confocal microscopy we showed that LRRK2 and NOD2 proteins interacted in RAW cells and monocyte-derived macrophages, and that this interaction was substantially reduced for the NOD2 R702W mutation. Moreover, we observed a joint effect of LRRK2 and NOD2 variants on Bacillus Calmette-Guérin (BCG)-induced respiratory burst, NF-κB activation and cytokine/chemokine secretion with a strong impact for the genotypes found in the twins consistent with a role of the identified mutations in the development of early onset leprosy.


Asunto(s)
Predisposición Genética a la Enfermedad , Lepra , Niño , Humanos , Alelos , Genotipo , Lepra/genética , Mutación , Proteína Adaptadora de Señalización NOD2/genética , Proteína 2 Quinasa Serina-Treonina Rica en Repeticiones de Leucina/genética
2.
BMC Microbiol ; 14: 238, 2014 Sep 10.
Artículo en Inglés | MEDLINE | ID: mdl-25213265

RESUMEN

BACKGROUND: Trypanosoma cruzi, the etiologic agent of Chagas disease, alternates between distinct morphological and functional forms during its life cycle. Axenic multiplication and differentiation processes of this protozoan parasite can be reproduced in vitro, enabling the isolation and study of the different evolutionary forms. Although there are several publications attempting the cultivation of T. cruzi under chemically defined conditions, in our experience none of the published media are capable of maintaining T. cruzi in continuous growth. RESULTS: In this work we modified a known chemically defined medium for Trypanosoma brucei growth. The resulting LM14 and LM14B defined media enabled cultivation of five different strains of T. cruzi for more than forty passages until now. The parasite's biological characteristics such as morphology and differentiation to metacyclic trypomastigotes were maintained when defined media is used. CONCLUSIONS: The establishment of a defined medium for T. cruzi cultivation is an important tool for basic biological research allowing several different approaches, providing new perspectives for further studies related to cell biology of this parasite.


Asunto(s)
Medios de Cultivo/metabolismo , Trypanosoma brucei brucei/crecimiento & desarrollo , Trypanosoma cruzi/crecimiento & desarrollo
3.
Malar J ; 12: 180, 2013 Jun 03.
Artículo en Inglés | MEDLINE | ID: mdl-23731624

RESUMEN

BACKGROUND: Simian malaria is still an open question concerning the species of Plasmodium parasites and species of New World monkeys susceptible to the parasites. In addition, the lingering question as to whether these animals are reservoirs for human malaria might become important especially in a scenario of eradication of the disease. To aid in the answers to these questions, monkeys were surveyed for malaria parasite natural infection in the Amazonian state of Rondônia, Brazil, a state with intense environmental alterations due to human activities, which facilitated sampling of the animals. METHODS: Parasites were detected and identified in DNA from blood of monkeys, by PCR with primers for the 18S rRNA, CSP and MSP1 genes and sequencing of the amplified fragments. Multiplex PCR primers for the 18S rRNA genes were designed for the parasite species Plasmodium falciparum and Plasmodium vivax, Plasmodium malariae/Plasmodium brasilianum and Plasmodium simium. RESULTS: An overall infection rate of 10.9% was observed or 20 out 184 monkey specimens surveyed, mostly by P. brasilianum. However, four specimens of monkeys were found infected with P. falciparum, two of them doubly infected with P. brasilianum and P. falciparum. In addition, a species of monkey of the family Aotidae, Aotus nigriceps, is firstly reported here naturally infected with P. brasilianum. None of the monkeys surveyed was found infected with P. simium/P. vivax. CONCLUSION: The rate of natural Plasmodium infection in monkeys in the Brazilian state of Rondônia is in line with previous surveys of simian malaria in the Amazon region. The fact that a monkey species was found that had not previously been described to harbour malaria parasites indicates that the list of monkey species susceptible to Plasmodium infection is yet to be completed. Furthermore, finding monkeys in the region infected with P. falciparum clearly indicates parasite transfer from humans to the animals. Whether this parasite can be transferred back to humans and how persistent the parasite is in monkeys in the wild so to be efficient reservoirs of the disease, is yet to be evaluated. Finding different species of monkeys infected with this parasite species suggests indeed that these animals can act as reservoirs of human malaria.


Asunto(s)
Malaria/veterinaria , Enfermedades de los Primates/epidemiología , Enfermedades de los Primates/parasitología , Animales , Sangre/parasitología , Brasil/epidemiología , ADN Protozoario/química , ADN Protozoario/genética , ADN Ribosómico/química , ADN Ribosómico/genética , Genes de ARNr , Malaria/epidemiología , Malaria/parasitología , Datos de Secuencia Molecular , Plasmodium/clasificación , Plasmodium/genética , Plasmodium/aislamiento & purificación , Reacción en Cadena de la Polimerasa , Prevalencia , ARN Protozoario/genética , ARN Ribosómico 18S/genética , Análisis de Secuencia de ADN
4.
Biochem Biophys Res Commun ; 420(2): 302-7, 2012 Apr 06.
Artículo en Inglés | MEDLINE | ID: mdl-22425988

RESUMEN

Trypanosoma cruzi is the causative agent of Chagas disease, a neglected disorder that affects millions of people in the Americas. T. cruzi relies mostly upon post-transcriptional regulation to control stage specific gene expression. RNA binding proteins (RBPs) associate with functionally related mRNAs forming ribonucleoprotein complexes that define post-transcriptional operons. The RNA Recognition Motif (RRM) is the most common and ancient family of RBPs. This family of RBPs has been identified in trypanosomatid parasites and only a few of them have been functionally characterized. We describe here the functional characterization of TcRBP40, a T. cruzi specific RBP, and its associated mRNAs. We used a modified version of the recombinant RIP-Chip assay to identify the mRNAs with which it associates and in vivo TAP-tag assays to confirm these results. TcRBP40 binds to an AG-rich sequence in the 3'UTR of the associated mRNAs, which were found to encode mainly putative transmembrane proteins. TcRBP40 is differentially expressed in metacyclogenesis. Surprisingly, in epimastigotes, it is dispersed in the cytoplasm but is concentrated in the reservosomes, a T. cruzi specific organelle, which suggests a putative new function for this parasite organelle.


Asunto(s)
Proteínas Protozoarias/metabolismo , ARN Mensajero/metabolismo , Proteínas de Unión al ARN/metabolismo , Trypanosoma cruzi/metabolismo , Secuencia de Bases , Proteínas Protozoarias/genética , Proteínas de Unión al ARN/genética , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo
5.
J Virol ; 85(11): 5374-83, 2011 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-21450836

RESUMEN

A recent (2007 to 2009) dengue outbreak caused by dengue virus (DENV) in Paraguay presented unusual severe clinical outcomes associated with 50% mortality rates. Although it has been reported that inflammatory responses influence the severity of dengue virus infection (T. Pang, M. J. Cardosa, and M. G. Guzman, Immunol. Cell Biol. 85:43-45, 2007), there remains a paucity of information on virus-innate immunity interactions influencing clinical outcome. Using human dendritic cells from a major innate immune cell population as an in vitro model, we have investigated signature cytokine responses as well as infectivity-replicative profiles of DENV clinical isolates from either a nonfatal case of classical dengue fever (strain DENV3/290; isolated in Brazil in 2002) or a fatal case of dengue fever with visceral complications isolated in Paraguay in 2007 (strain DENV3/5532). Strain DENV3/5532 was found to display significantly higher replicative ability than DENV3/290 in monocyte-derived dendritic cells (mdDCs). In addition, compared to DENV3/290 results, mdDCs exposed to DENV3/5532 showed increased production of proinflammatory cytokines associated with higher rates of programmed cell death, as shown by annexin V staining. The observed phenotype was due to viral replication, and tumor necrosis factor alpha (TNF-α) appears to exert a protective effect on virus-induced mdDC apoptosis. These results suggest that the DENV3/5532 strain isolated from the fatal case replicates within human dendritic cells, modulating cell survival and synthesis of inflammatory mediators.


Asunto(s)
Apoptosis , Citocinas/metabolismo , Células Dendríticas/inmunología , Células Dendríticas/virología , Virus del Dengue/patogenicidad , Dengue/virología , Brasil , Virus del Dengue/aislamiento & purificación , Humanos , Datos de Secuencia Molecular , Paraguay , ARN Viral/genética , Análisis de Secuencia de ADN , Replicación Viral
6.
BMC Microbiol ; 12: 22, 2012 Feb 09.
Artículo en Inglés | MEDLINE | ID: mdl-22321871

RESUMEN

BACKGROUND: The experimental murine model of leishmaniasis has been widely used to characterize the immune response against Leishmania. CBA mice develop severe lesions, while C57BL/6 present small chronic lesions under L. amazonensis infection. Employing a transcriptomic approach combined with biological network analysis, the gene expression profiles of C57BL/6 and CBA macrophages, before and after L. amazonensis infection in vitro, were compared. These strains were selected due to their different degrees of susceptibility to this parasite. RESULTS: The genes expressed by C57BL/6 and CBA macrophages, before and after infection, differ greatly, both with respect to absolute number as well as cell function. Uninfected C57BL/6 macrophages express genes involved in the deactivation pathway of macrophages at lower levels, while genes related to the activation of the host immune inflammatory response, including apoptosis and phagocytosis, have elevated expression levels. Several genes that participate in the apoptosis process were also observed to be up-regulated in C57BL/6 macrophages infected with L. amazonensis, which is very likely related to the capacity of these cells to control parasite infection. By contrast, genes involved in lipid metabolism were found to be up-regulated in CBA macrophages in response to infection, which supports the notion that L. amazonensis probably modulates parasitophorous vacuoles in order to survive and multiply in host cells. CONCLUSION: The transcriptomic profiles of C57BL/6 macrophages, before and after infection, were shown to be involved in the macrophage pathway of activation, which may aid in the control of L. amazonensis infection, in contrast to the profiles of CBA cells.


Asunto(s)
Perfilación de la Expresión Génica , Interacciones Huésped-Patógeno , Leishmania mexicana/inmunología , Leishmania mexicana/patogenicidad , Macrófagos/inmunología , Macrófagos/parasitología , Animales , Células Cultivadas , Femenino , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Endogámicos CBA , Análisis por Micromatrices , Reacción en Cadena en Tiempo Real de la Polimerasa
7.
Infect Immun ; 79(5): 1855-62, 2011 May.
Artículo en Inglés | MEDLINE | ID: mdl-21343357

RESUMEN

Chagas' disease, caused by the hemoflagellate protozoan Trypanosoma cruzi, affects millions of people in South and Central America. Chronic chagasic cardiomyopathy, the most devastating manifestation of this disease, occurs in approximately one-third of infected individuals. Events associated with the parasite's tropism for and invasion of cardiomyocytes have been the focus of intense investigation in recent years. In the present study, we use murine microarrays to investigate the cellular response caused by invasion of primary murine cardiomyocytes by T. cruzi trypomastigotes. These studies identified 353 murine genes that were differentially expressed during the early stages of invasion and infection of these cells. Genes associated with the immune response, inflammation, cytoskeleton organization, cell-cell and cell-matrix interactions, apoptosis, cell cycle, and oxidative stress are among those affected during the infection. Our data indicate that T. cruzi induces broad modulations of the host cell machinery in ways that provide insight into how the parasite survives, replicates, and persists in the infected host and ultimately defines the clinical outcome of the infection.


Asunto(s)
Cardiomiopatía Chagásica/genética , Perfilación de la Expresión Génica , Interacciones Huésped-Parásitos/genética , Miocitos Cardíacos/parasitología , Animales , Cardiomiopatía Chagásica/inmunología , Cardiomiopatía Chagásica/parasitología , Expresión Génica , Interacciones Huésped-Parásitos/inmunología , Hibridación in Situ , Ratones , Análisis por Micromatrices , Miocitos Cardíacos/inmunología , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Trypanosoma cruzi
8.
PLoS Negl Trop Dis ; 15(10): e0009899, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-34705820

RESUMEN

Poly(A) Binding Proteins (PABPs) are major eukaryotic RNA-binding proteins (RBPs) with multiple roles associated with mRNA stability and translation and characterized mainly from multicellular organisms and yeasts. A variable number of PABP homologues are seen in different organisms however the biological reasons for multiple PABPs are generally not well understood. In the unicellular Leishmania, dependent on post-transcriptional mechanisms for the control of its gene expression, three distinct PABPs are found, with yet undefined functional distinctions. Here, using RNA-immunoprecipitation sequencing analysis we show that the Leishmania PABP1 preferentially associates with mRNAs encoding ribosomal proteins, while PABP2 and PABP3 bind to an overlapping set of mRNAs distinct to those enriched in PABP1. Immunoprecipitation studies combined to mass-spectrometry analysis identified RBPs differentially associated with PABP1 or PABP2, including RBP23 and DRBD2, respectively, that were investigated further. Both RBP23 and DRBD2 bind directly to the three PABPs in vitro, but reciprocal experiments confirmed preferential co-immunoprecipitation of PABP1, as well as the EIF4E4/EIF4G3 based translation initiation complex, with RBP23. Other RBP23 binding partners also imply a direct role in translation. DRBD2, in contrast, co-immunoprecipitated with PABP2, PABP3 and with RBPs unrelated to translation. Over 90% of the RBP23-bound mRNAs code for ribosomal proteins, mainly absent from the transcripts co-precipitated with DRBD2. These experiments suggest a novel and specific route for translation of the ribosomal protein mRNAs, mediated by RBP23, PABP1 and the associated EIF4E4/EIF4G3 complex. They also highlight the unique roles that different PABP homologues may have in eukaryotic cells associated with mRNA translation.


Asunto(s)
Leishmania/metabolismo , Proteínas de Unión a Poli(A)/metabolismo , Proteínas Protozoarias/metabolismo , ARN Mensajero/metabolismo , Proteínas de Unión al ARN/metabolismo , Proteínas Ribosómicas/metabolismo , Leishmania/genética , Proteínas de Unión a Poli(A)/genética , Unión Proteica , Biosíntesis de Proteínas , Proteínas Protozoarias/genética , ARN Mensajero/genética , Proteínas de Unión al ARN/genética , Proteínas Ribosómicas/genética
9.
BMC Microbiol ; 10: 259, 2010 Oct 13.
Artículo en Inglés | MEDLINE | ID: mdl-20942965

RESUMEN

BACKGROUND: The three trypanosomatids pathogenic to men, Trypanosoma cruzi, Trypanosoma brucei and Leishmania major, are etiological agents of Chagas disease, African sleeping sickness and cutaneous leishmaniasis, respectively. The complete sequencing of these trypanosomatid genomes represented a breakthrough in the understanding of these organisms. Genome sequencing is a step towards solving the parasite biology puzzle, as there are a high percentage of genes encoding proteins without functional annotation. Also, technical limitations in protein expression in heterologous systems reinforce the evident need for the development of a high-throughput reverse genetics platform. Ideally, such platform would lead to efficient cloning and compatibility with various approaches. Thus, we aimed to construct a highly efficient cloning platform compatible with plasmid vectors that are suitable for various approaches. RESULTS: We constructed a platform with a flexible structure allowing the exchange of various elements, such as promoters, fusion tags, intergenic regions or resistance markers. This platform is based on Gateway® technology, to ensure a fast and efficient cloning system. We obtained plasmid vectors carrying genes for fluorescent proteins (green, cyan or yellow), and sequences for the c-myc epitope, and tandem affinity purification or polyhistidine tags. The vectors were verified by successful subcellular localization of two previously characterized proteins (TcRab7 and PAR 2) and a putative centrin. For the tandem affinity purification tag, the purification of two protein complexes (ribosome and proteasome) was performed. CONCLUSIONS: We constructed plasmids with an efficient cloning system and suitable for use across various applications, such as protein localization and co-localization, protein partner identification and protein expression. This platform also allows vector customization, as the vectors were constructed to enable easy exchange of its elements. The development of this high-throughput platform is a step closer towards large-scale trypanosome applications and initiatives.


Asunto(s)
Clonación Molecular/métodos , Trypanosoma cruzi/genética , Datos de Secuencia Molecular , Plásmidos , Proteínas Protozoarias/análisis , Proteínas Protozoarias/genética , Transfección , Trypanosoma cruzi/química , Trypanosoma cruzi/citología
10.
Nucleic Acids Res ; 36(Database issue): D547-52, 2008 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-17981844

RESUMEN

ProtozoaDB (http://www.biowebdb.org/protozoadb) is being developed to initially host both genomics and post-genomics data from Plasmodium falciparum, Entamoeba histolytica, Trypanosoma brucei, T. cruzi and Leishmania major, but will hopefully host other protozoan species as more genomes are sequenced. It is based on the Genomics Unified Schema and offers a modern Web-based interface for user-friendly data visualization and exploration. This database is not intended to duplicate other similar efforts such as GeneDB, PlasmoDB, TcruziDB or even TDRtargets, but to be complementary by providing further analyses with emphasis on distant similarities (HMM-based) and phylogeny-based annotations including orthology analysis. ProtozoaDB will be progressively linked to the above-mentioned databases, focusing in performing a multi-source dynamic combination of information through advanced interoperable Web tools such as Web services. Also, to provide Web services will allow third-party software to retrieve and use data from ProtozoaDB in automated pipelines (workflows) or other interoperable Web technologies, promoting better information reuse and integration. We also expect ProtozoaDB to catalyze the development of local and regional bioinformatics capabilities (research and training), and therefore promote/enhance scientific advancement in developing countries.


Asunto(s)
Bases de Datos Genéticas , Genoma de Protozoos , Animales , Gráficos por Computador , Entamoeba histolytica/genética , Genómica , Internet , Leishmania major/genética , Plasmodium falciparum/genética , Proteínas Protozoarias/química , Programas Informáticos , Trypanosoma brucei brucei/genética , Trypanosoma cruzi/genética , Interfaz Usuario-Computador
11.
Mem Inst Oswaldo Cruz ; 104 Suppl 1: 136-41, 2009 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-19753468

RESUMEN

A new multiplex assay platform was evaluated to detect Trypanosoma cruzi infection using the recombinant antigens CRA, FRA, CRAFRA fusion and parasite lysate. The antigens presented different sensitivity and specificity in a singleplex test when compared to a serial dilution of two pools comprising 10 positive serum samples and one pool of 10 negative samples. The recombinant protein CRA presented lower sensitivity (55%) in contrast to the 100% specificity and sensitivity of FRA, CRAFRA and T. cruzi lysate. These antigens also showed good results in a duplex test and the duplex test with CRAFRA/T. cruzi lysate showed better performance with 100% specificity and sensitivity, as well as a lower cut-off value in comparison to the other duplex test, FRA/T. cruzi lysate. Hence, when the antigens were used in duplex format, both tests showed decreased cut-off values and no interference between different bead sets, resulting in increasing sensitivity and specificity. The results of these multiplex tests show that they could be an alternative to singleplex detection for Chagas disease, and also indicate the necessity of using multiplex diagnostic tools to increase the sensitivity and specificity for diagnostic tests. Emerging data from the T. cruzi genome and from its ORFeome project will also allow the identification of new antigens for this disease detection application.


Asunto(s)
Antígenos de Protozoos , Enfermedad de Chagas/diagnóstico , Inmunoensayo/métodos , Estudios de Casos y Controles , Humanos , Microesferas , Proteínas Recombinantes , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
12.
J Cell Biochem ; 104(4): 1364-77, 2008 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-18286468

RESUMEN

Canova (CA) is a complex homeopathic medication used in diseases where the immune system is depressed. Previous studies demonstrated that it is neither toxic nor mutagenic and activates macrophages. We now evaluate CA effects on cytokine production and gene expression from mice macrophages. The global view of changes in expression of genes with known functions can provide a vivid picture of the way in which cell adapts to a changing environment or a challenge. We found a decrease in IL-2 and IL-4 production and a differential expression in 147 genes from CA group. These genes are mainly involved in transcription/translation, cell structure and dynamics, immune response, cytoprotection, enzymatic process, and receptors/ligands. With gene expression analysis we state that this medication provokes a reaction that involves alterations in gene expression profile mainly in the ones involved with macrophages activation, corroborating the laboratorial research and the clinical data.


Asunto(s)
Venenos de Crotálidos/farmacología , Perfilación de la Expresión Génica , Factores Inmunológicos/farmacología , Macrófagos/efectos de los fármacos , Extractos Vegetales/farmacología , Animales , Venenos de Crotálidos/administración & dosificación , Citocinas/biosíntesis , Factores Inmunológicos/administración & dosificación , Activación de Macrófagos/efectos de los fármacos , Activación de Macrófagos/genética , Ratones , Extractos Vegetales/administración & dosificación
13.
Acta Trop ; 107(1): 59-65, 2008 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-18501872

RESUMEN

Differential gene expression in three pairs of Trypanosoma cruzi populations or clones susceptible or resistant to benznidazole (BZ) was investigated by differential display (DD) and representation of differential expression (RDE). GenBank searches of 14 genes selected by DD showed that four sequences corresponded to different hypothetical proteins and the others were very similar to T. cruzi genes encoding mucin (TcMUC), dihydrolipoamide dehydrogenase (TcLipDH), the hexose transporter (TcHT), or a ribosomal protein. Sequence analysis was performed on 34 clones obtained by RDE; approximately half of these clones encoded 14 different hypothetical proteins and the other half encoded proteins involved with stress response, antioxidant defence, metabolism, transporter proteins, surface proteins, ribosomal proteins and others. The mRNA levels of eight T. cruzi genes obtained by RDE and DD were analysed by northern blotting to confirm the differential expression of these sequences. For six of the eight genes, TcLipDH, TcHT, TcFeSOD-A (iron superoxide dismutase-A), TcHSP70, TcHSP100 (heat shock protein) and Tc52 (thiol-transferase), mRNA levels in the drug-resistant T. cruzi population were at least twice those in the susceptible population. Further analysis of TcHSP70 showed that although the levels of TcHSP70 mRNA were four-fold higher in T. cruzi BZ-resistant population, no corresponding increase was observed in the levels of TcHSP70 protein expression. The results suggest that TcHSP70 is not directly associated with the T. cruzi drug resistance phenotype.


Asunto(s)
Antimaláricos/farmacología , Resistencia a Medicamentos , Perfilación de la Expresión Génica , Nitroimidazoles/farmacología , Trypanosoma cruzi/genética , Animales , Northern Blotting , ADN Protozoario/química , ADN Protozoario/genética , Genes Protozoarios , Datos de Secuencia Molecular , Proteínas Protozoarias/genética , ARN Mensajero/biosíntesis , ARN Mensajero/genética , ARN Protozoario/biosíntesis , ARN Protozoario/genética , Análisis de Secuencia de ADN , Trypanosoma cruzi/efectos de los fármacos
14.
J Proteomics ; 154: 118-127, 2017 02 10.
Artículo en Inglés | MEDLINE | ID: mdl-28039027

RESUMEN

Protein phosphorylation and dephosphorylation events regulate many cellular processes. The identification of all phosphorylation sites and their association to a respective protein kinase or phosphatase is a challenging and crucial step to have a deeper understanding of the effects of signaling networks on cells. Pathogenic trypanosomatids have a large number of protein kinases and phosphatases in comparison to other organisms, which reinforces the relevance of the phosphorylation process in these early eukaryotes, nevertheless little is known about protein phosphorylation in these protozoa. In this context, the role of a MAP kinase-like kinase (MAPKLK1), observed to be essential to proliferation of procyclic Trypanosoma brucei, was studied. After silencing MAPKLK1 expression by RNAi, the cells were evaluated by SILAC MS-based proteomics and RNA-Seq. We identified 1756 phosphorylation sites of which 384 were not previously described in T. brucei. Despite being essential, few modulations were observed at the phosphorylation patterns and gene expression levels of MAPKLK1 knockdown. These indirect targets and potential substrates of MAPKLK1 are related to key cellular processes enriched to mRNA processing and stability control. SIGNIFICANCE: The field of cell signaling is a promising topic of study for trypanosomatids, since little is known about this topic and the gene expression regulation occurs at post-transcriptional level. In this sense, the present work increases the knowledge on protein phosphorylation process in Trypanosoma brucei. We depleted one MAP kinase (MAPKLK1) of T. brucei and evaluated the effects on the cell. We showed that MAPKLK1 is essential to the cell, while few modulations on phosphoproteome, proteome and transcriptome are observed with its depletion. Although in low number, the changes in phosphoproteome were significant, presenting possible substrate candidates of MAPKLK1 and indirect targets related to mRNA processing and stability control, metabolic pathways, among others. This result provides insights in the phosphorylation network of T. brucei, a model organism that impacts human and animal health.


Asunto(s)
Proteínas Quinasas/fisiología , Proteínas Protozoarias/análisis , Trypanosoma brucei brucei/química , Proliferación Celular , Regulación de la Expresión Génica , Silenciador del Gen , Fosfoproteínas/análisis , Fosforilación , Proteínas Quinasas/genética , Proteínas Quinasas/metabolismo , Proteómica/métodos , ARN Mensajero/metabolismo , ARN Protozoario/metabolismo , Trypanosoma brucei brucei/citología , Trypanosoma brucei brucei/fisiología
15.
Mol Biochem Parasitol ; 146(2): 151-62, 2006 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-16442642

RESUMEN

Old yellow enzyme (OYE) is a NAD(P)H flavin oxidoreductase that in Trypanosoma cruzi (TcOYE) catalyzes prostaglandin PGF2alpha synthesis and reduction of some trypanocidal drugs. We performed DNA microarray analysis and it revealed that the levels of transcription of the TcOYE gene were six-fold lower in a T. cruzi population with in vitro-induced resistance to benznidazole (BZ) (17LER) than in the wild-type (17WTS). Further we investigated the TcOYE levels in 15 T. cruzi strains and clones that were either susceptible or naturally resistant to BZ and nifurtimox, or had in vivo-selected resistance to BZ. Northern blot and real-time RT-PCR analyses confirmed our finding that TcOYE transcription levels were lower in 17LER than in 17WTS. In contrast, we detected no differences in TcOYE transcription levels between other T. cruzi samples. All T. cruzi strains contained four copies of TcOYE gene, except 17LER that contained only one. A 42kDa TcOYE protein was detected in all T. cruzi strains tested. The expression of this protein was similar for all samples, with the exception of 17LER for which the protein was nearly seven-fold less expressed. The chromosomal location of the TcOYE gene and the polymorphisms detected in TcOYE nucleotide and amino acid sequences of the T. cruzi strains are associated with the zymodeme but not with drug-resistance phenotype. Our data show that one of the mechanisms conferring in vitro-induced BZ resistance to T. cruzi correlates with deletion of copies of the TcOYE gene. In contrast, the in vivo and natural resistance to BZ are mediated by different mechanisms.


Asunto(s)
Farmacorresistencia Fúngica/genética , Eliminación de Gen , NADPH Deshidrogenasa/genética , Nitroimidazoles/farmacología , Trypanosoma cruzi/efectos de los fármacos , Trypanosoma cruzi/genética , Animales , Antifúngicos/farmacología , Northern Blotting , ADN de Hongos/química , ADN de Hongos/genética , Proteínas Fúngicas/análisis , Dosificación de Gen , Perfilación de la Expresión Génica , Datos de Secuencia Molecular , Peso Molecular , Nifurtimox/farmacología , Análisis de Secuencia por Matrices de Oligonucleótidos , Polimorfismo Genético , ARN de Hongos/análisis , ARN Mensajero/análisis , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Análisis de Secuencia de ADN , Homología de Secuencia
16.
Parasit Vectors ; 8: 346, 2015 Jun 25.
Artículo en Inglés | MEDLINE | ID: mdl-26109388

RESUMEN

BACKGROUND: Trypanosoma cruzi, the etiological agent of Chagas disease, is auxotrophic for arginine. It obtains this amino acid from the host through transporters expressed on the plasma membrane and on the membranes of intracellular compartments. A few cationic amino acid transporters have been characterized at the molecular level, such as the novel intracellular arginine/ornithine transporter, TcCAT1.1, a member of the TcCAT subfamily that is composed of four almost identical open reading frames in the T. cruzi genome. METHODS: The functional characterization of the TcCAT1.1 isoform was performed in two heterologous expression systems. TcCAT subfamily expression was evaluated by real-time PCR in polysomal RNA fractions, and the cellular localization of TcCAT1.1 fused to EGFP was performed by confocal and immunoelectron microscopy. RESULTS: In the S. cerevisiae expression system, TcCAT1.1 showed high affinity for arginine (K m = 0.085 ± 0.04 mM) and low affinity for ornithine (K m = 1.7 ± 0.2 mM). Xenopus laevis oocytes expressing TcCAT1.1 showed a 7-fold increase in arginine uptake when they were pre-loaded with arginine, indicating that transport is enhanced by substrates on the trans side of the membrane (trans-stimulation). Oocytes that were pre-loaded with [(3)H]-arginine displayed a 16-fold higher efflux of [(3)H]-arginine compared with that of the control. Analysis of polysomal RNA fractions demonstrated that the expression of members of the arginine transporter TcCAT subfamily is upregulated under nutritional stress and that this upregulation precedes metacyclogenesis. To investigate the cellular localization of the transporter, EGFP was fused to TcCAT1.1, and fluorescence microscopy and immunocytochemistry revealed the intracellular labeling of vesicles in the anterior region, in a network of tubules and vesicles. CONCLUSIONS: TcCAT1.1 is a novel arginine/ornithine transporter, an exchanger expressed in intracellular compartments that is physiologically involved in arginine homeostasis throughout the T. cruzi life cycle. The properties and estimated kinetic parameters of TcCAT1.1 can be extended to other members of the TcCAT subfamily.


Asunto(s)
Sistemas de Transporte de Aminoácidos Básicos/metabolismo , Arginina/metabolismo , Enfermedad de Chagas/parasitología , Genoma de Protozoos , Familia de Multigenes , Proteínas Protozoarias/metabolismo , Trypanosoma cruzi/genética , Trypanosoma cruzi/metabolismo , Secuencia de Aminoácidos , Sistemas de Transporte de Aminoácidos Básicos/genética , Animales , Humanos , Masculino , Ratones Endogámicos BALB C , Datos de Secuencia Molecular , Proteínas Protozoarias/genética , Alineación de Secuencia
17.
Genet Test ; 7(3): 213-8, 2003.
Artículo en Inglés | MEDLINE | ID: mdl-14641997

RESUMEN

Cystic fibrosis (CF) is an autosomal recessive disease caused by at least 1,000 different mutations in the cystic fibrosis transmembrane conductance regulator gene (CFTR). To determine the frequency of 70 common worldwide CFTR mutations in 155 Euro-Brazilian CF patients and in 38 Afro-Brazilian CF patients, we used direct PCR amplification of DNA from a total of 386 chromosomes from CF patients born in three different states of Brazil. The results show that screening for seventy mutations accounts for 81% of the CF alleles in Euro-Brazilians, but only 21% in the Afro-Brazilian group. We found 21 different mutations in Euro-Brazilians and only 7 mutations in Afro-Brazilians. The frequency of mutations and the number of different mutations detected in Euro-Brazilians are different from Northern European and North American populations, but similar to Southern European populations; in Afro-Brazilians, the mix of CF-mutations is different from those reported in Afro-American CF patients. We also found significant differences in detection rates between Euro-Brazilian (75%) and Afro-Brazilian CF patients (21%) living in the same state, Minas Gerais. These results, therefore, have implications for the use of DNA-based tests for risk assessment in heterogeneous populations like the Brazilians. Further studies are needed to identify the remaining CF mutations in the different populations and regions of Brazil.


Asunto(s)
Fibrosis Quística/genética , Heterogeneidad Genética , Pruebas Genéticas/métodos , Adolescente , Adulto , Alelos , Población Negra/genética , Brasil/etnología , Niño , Preescolar , Fibrosis Quística/diagnóstico , Regulador de Conductancia de Transmembrana de Fibrosis Quística/genética , Femenino , Frecuencia de los Genes , Genética de Población , Humanos , Lactante , Masculino , Mutación , Población Blanca/genética
18.
BMC Res Notes ; 7: 132, 2014 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-24606808

RESUMEN

BACKGROUND: The STINGRAY system has been conceived to ease the tasks of integrating, analyzing, annotating and presenting genomic and expression data from Sanger and Next Generation Sequencing (NGS) platforms. FINDINGS: STINGRAY includes: (a) a complete and integrated workflow (more than 20 bioinformatics tools) ranging from functional annotation to phylogeny; (b) a MySQL database schema, suitable for data integration and user access control; and (c) a user-friendly graphical web-based interface that makes the system intuitive, facilitating the tasks of data analysis and annotation. CONCLUSION: STINGRAY showed to be an easy to use and complete system for analyzing sequencing data. While both Sanger and NGS platforms are supported, the system could be faster using Sanger data, since the large NGS datasets could potentially slow down the MySQL database usage. STINGRAY is available at http://stingray.biowebdb.org and the open source code at http://sourceforge.net/projects/stingray-biowebdb/.


Asunto(s)
Biología Computacional/métodos , Genómica/métodos , Programas Informáticos , Flujo de Trabajo , Bases de Datos Factuales/estadística & datos numéricos , Secuenciación de Nucleótidos de Alto Rendimiento/estadística & datos numéricos , Internet , Filogenia , Reproducibilidad de los Resultados
19.
Evol Bioinform Online ; 10: 131-53, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25336895

RESUMEN

Leishmaniasis is an infectious disease caused by Leishmania species. Leishmania amazonensis is a New World Leishmania species belonging to the Mexicana complex, which is able to cause all types of leishmaniasis infections. The L. amazonensis reference strain MHOM/BR/1973/M2269 was sequenced identifying 8,802 codifying sequences (CDS), most of them of hypothetical function. Comparative analysis using six Leishmania species showed a core set of 7,016 orthologs. L. amazonensis and Leishmania mexicana share the largest number of distinct orthologs, while Leishmania braziliensis presented the largest number of inparalogs. Additionally, phylogenomic analysis confirmed the taxonomic position for L. amazonensis within the "Mexicana complex", reinforcing understanding of the split of New and Old World Leishmania. Potential non-homologous isofunctional enzymes (NISE) were identified between L. amazonensis and Homo sapiens that could provide new drug targets for development.

20.
PLoS One ; 6(9): e25381, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-21966514

RESUMEN

Protein phosphorylation is a reversible post-translational modification essential for the regulation of several signal transduction pathways and biological processes in the living cell. Therefore, the identification of protein phosphorylation sites is crucial to understand cell signaling control at the molecular level. Based on mass spectrometry, recent studies have reported the large-scale mapping of phosphorylation sites in various eukaryotes and prokaryotes. However, little is known about the impact of phosphorylation in protozoan parasites. To in depth characterize the phosphoproteome of Trypanosoma cruzi, a parasite of the Kinetoplastida class, protein samples from cells at different phases of the metacyclogenesis--differentiation process of the parasites from non-infective epimastigotes to infective metacyclic trypomastigotes--were enriched for phosphopeptides using TiO(2) chromatography and analyzed on an LTQ-Orbitrap mass spectrometer. In total, 1,671 proteins were identified, including 753 phosphoproteins, containing a total of 2,572 phosphorylation sites. The distribution of phosphorylated residues was 2,162 (84.1%) on serine, 384 (14.9%) on threonine and 26 (1.0%) on tyrosine. Here, we also report several consensus phosphorylation sequence motifs and as some of these conserved groups have enriched biological functions, we can infer the regulation by protein kinases of this functions. To our knowledge, our phosphoproteome is the most comprehensive dataset identified until now for Kinetoplastida species. Here we also were able to extract biological information and infer groups of sites phosphorylated by the same protein kinase. To make our data accessible to the scientific community, we uploaded our study to the data repositories PHOSIDA, Proteome Commons and TriTrypDB enabling researchers to access information about the phosphorylation sites identified here.


Asunto(s)
Fosfoproteínas/metabolismo , Proteoma/metabolismo , Trypanosoma cruzi/metabolismo , Espectrometría de Masas , Espectrometría de Masas en Tándem
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA