Protein disulfide isomerase and heat shock cognate protein 70 interactions with rotavirus structural proteins using their purified recombinant versions / Interacciones de las proteínas disulfuro isomerasa y de choque térmico Hsc70 con proteínas estructurales recombinantes purificadas de rotavirus

Introduction. Rotavirus entry into cells seems to be mediated by sequential interactions between viral structural proteins and some cell surface molecules. However, the mechanisms by which rotavirus infects target cell are still not well understood. There is some evidence showing that rotavirus structural proteins VP5* and VP8* interact with some cell surface molecules. The availability of recombinant rotavirus structural proteins in sufficient quantity has become very important for the identification of the specific virus-cell receptor interactions during the early events of the infectious process. Objective. The aim of the present work is to perform an analysis of the interactions between recombinant rotavirus structural proteins VP5*, VP8* and VP6, and cellular proteins Hsc70 and PDI using their purified recombinant versions. Materials and methods. Rotavirus recombinant VP5* and VP8*, and cellular recombinant proteins Hsc70 and PDI were expressed in E. coli BL21(DE3) while VP6 was expressed in recombinant vaccinia virus-transfected MA104 cells. The interaction between rotavirus and cellular proteins was studied using ELISA, co-immunoprecipitation and SDS-PAGE/Western blotting analysis. Results. The optimal conditions for expression of recombinant proteins were determined and antibodies were raised against them. The findings suggested that viral proteins rVP5* and rVP6 interact with Hsc70 and PDI in vitro. These viral recombinant proteins were also found to interact with raft-associated Hsc70 in a cell culture system. The treatment of cells with either rVP6 or DLPs produced significantly inhibition of rotavirus infection. Conclusion. The results allow us to conclude that rVP5* and rVP6 interact with Hsc70 and PDI during the rotavirus infection process.

Introducción. La entrada de rotavirus a las células parece estar mediado por interacciones secuenciales entre las proteínas estructurales virales y algunas moléculas de la superficie celular. Sin embargo, los mecanismos por los cuales el rotavirus infecta la célula diana aún no se comprenden bien. Existe alguna evidencia que muestra que las proteínas estructurales de rotavirus VP5* y VP8* interactúan con algunas moléculas de la superficie celular. La disponibilidad de las proteínas estructurales de rotavirus recombinantes en cantidad suficiente se ha convertido en un aspecto importante para la identificación de las interacciones específicas de los receptores virus-célula durante los eventos tempranos del proceso infeccioso. Objetivo. El propósito del presente trabajo es realizar un análisis de las interacciones entre las proteínas estructurales de rotavirus recombinante VP5*, VP8* y VP6, y las proteínas celulares Hsc70 y PDI utilizando sus versiones recombinantes purificadas. Materiales y métodos. Las proteínas recombinantes de rotavirus VP5* y VP8* y las proteínas recombinantes celulares Hsc70 y PDI se expresaron en E. coli BL21 (DE3), mientras que VP6 se expresó en células MA104 con virus vaccinia recombinante transfectada. La interacción entre el rotavirus y las proteínas celulares se estudió mediante ELISA, co-inmunoprecipitación y SDS-PAGE/ Western. Resultados. Las condiciones óptimas para la expresión de proteínas recombinantes se determinaron y se generaron anticuerpos contra ellas. Los resultados sugirieron que las proteínas virales rVP5* y rVP6 interactúan con Hsc70 y PDI in vitro. También se encontró que éstas proteínas virales recombinantes interactúan con Hsc70 en las balsas lipídicas ("Rafts") en un cultivo celular. El tratamiento de las células, ya sea con DLP o rVP6 produjo significativamente la inhibición de la infección por rotavirus. Conclusión. Los resultados permiten concluir que rVP5 * y rVP6 interactúan con Hsc70 y PDI durante el proceso de la infección por rotavirus.

Measuring opportunity for natural selection: Adaptation among two linguistically cognate tribes inhabiting two eco-situations of North-East India.

BACKGROUND: Numerous literature on the migration of Mishings point out to the fact that the Mishing and the Minyong are two culturally and linguistically cognate tribes that co-existed in the same ecology in the hills of Arunachal Pradesh. The Mishing tribe after migration, now inhabits flood-prone areas of Brahmaputra valley of Assam. AIM: The study aims to measure the adaptation process of these two cognate tribes inhabiting two different ecologies at present: Hills and plains by calculating the index of selection intensity by Crow’s and Johnston and Kensinger’s formulae. MATERIALS AND METHODS: The reproductive histories of 77 Mishing mothers of completed fertility inhabiting a flood affected village of Assam and 74 Minyong mothers inhabiting a hilly village of Arunachal Pradesh are selected. RESULTS AND DISCUSSION: The Minyongs show higher average fertility than the Mishings. The proportion of embryonic death is higher, and child death is lower among the Mishings (0.1661; 0.1623) than the Minyongs (0.1319; 0.2238). The index of selection due to mortality component is contributing more toward the total index of selection in both the tribes. CONCLUSION: The contribution of mortality component is sizeable to the total selection like many other tribes of North-East India. Higher proportion of embryonic deaths among the Mishings infers that the causes are mostly biological whereas, the higher proportion of child deaths among the Minyongs infers that the causes are mostly socio-cultural.

Functional complementation in Saccharomyces cerevisiae under control of the natural yeast promoter

A novel approach for functional complementation of foreign genes in Saccharomyces cerevisiae is presented. This approach is based on the use of the widely available cognate gene plasmids (e.g. pRS416) of the European Functional Analysis Network (EUROFAN). The functional complementation of the human homolog of YOR159c (SME1 gene) shown here is the first demonstration of complementation using the original yeast promoter, theoretically offering a more natural regulation of protein expression