RESUMEN
In a 17-kb genomic fragment of Trypanosoma cruzi chromosome XX, we identified three tandemly linked genes coding for CX2CX4HX4C zinc finger proteins. We also showed that similar genes are present in T. brucei and Leishmania major, sharing three monophyletic groups among these trypanosomatids. In T. cruzi, TcZFP8 corresponds to a novel gene coding for a protein containing eight zinc finger motifs. Molecular cloning of this gene and heterologous expression as a fusion with a His-tag were performed in Escherichia coli. The purified recombinant protein was used to produce antibody in rabbits. Using Western blot analysis, we observed the presence of this protein in all three forms of the parasite: amastigote, trypomastigote and epimastigote. An analysis of cytoplasmic and nuclear cell extracts showed that this protein is present in nuclear extracts, and indirect immunofluorescence microscopy confirmed the nuclear localization of TcZFP8. Homologues of TcZFP8 in T. brucei are apparently absent, while one candidate in L. major was identified.
Asunto(s)
Animales , Conejos , Núcleo Celular/metabolismo , Código Genético/genética , Proteínas Protozoarias/genética , Trypanosoma cruzi/genética , Dedos de Zinc/genética , Secuencia de Bases , Western Blotting , Clonación Molecular , ADN Protozoario/genética , ADN Protozoario/metabolismo , Técnica del Anticuerpo Fluorescente Indirecta , Microscopía Fluorescente , Datos de Secuencia Molecular , Proteínas Protozoarias/metabolismo , ARN Protozoario/genética , ARN Protozoario/metabolismo , Trypanosoma cruzi/metabolismoRESUMEN
El papel crítico del remodelamiento de la cromatina en la expresión de los genes se halla bajo la influencia de los cambios epigenéticos que conforman un lenguaje inesperado en el DNA y las histonas. Este trabajo actualiza el conocimiento sobre la metilación del DNA y la acetilación de las histonas, con especial interés en su aplicación clínica. Se ha propuesto, la identificación de los patrones heredables de metilación como herramienta útil en el diagnóstico y pronóstico del cáncer. Los inhibidores de las DNA-metiltransferasas y de las desacetilasas de histonas que actúan como reprogramadores de la expresión génica, han generado una nueva y promisoria aproximación terapéutica
Asunto(s)
Código Genético/genética , Metilación de ADN , Terapia Biológica/métodos , Terapia Biológica/tendenciasRESUMEN
We have isolated and sequenced the genes encoding the membrane bound transglycosylase B (MltB) and the transferring binding protein B (TbpB) of the salmon pathogen Piscirickettsia salmonis. The results of the sequence revealed two open reading frames that encode proteins with calculated molecular weights of 38,830 and 85,140. The deduced aminoacid sequences of both proteins show a significant homology to the respective protein from phylogenetically related microorganisms. Partial sequences coding the amino and carboxyl regions of MltB and a sequence of 761 base pairs encoding the amino region of TbpB have been expressed in E. coli. The strong humoral response elicited by these proteins in mouse confirmed the immunogenic properties of the recombinant proteins. A similar response was elicited by both proteins when injected intraperitoneally in Atlantic salmon. The present data indicates that these proteins are good candidates to be used in formulations to study the protective immunity of salmon to infection by P. salmonis.