Molecular and structural characterization of the Leishmania RNA virus LRV1-4

Abstract

The study of protozoa is important for several reasons, including their diversity, their evolutionary importance and public health impact. The Leishmania RNA virus 1-4 (LRV1-4) is a virus belonging to the Totiviridae family with an icosahedral capsid structure that encodes two proteins (a capsid major protein and an RNA polymerase). Having limited investigation on this virus we initiated a its molecular characterization with the purpose of performing future structural and functional investigations. Recent data indicate the involvement of LRV1-4 in the Leishmania pathogenesis in the mammalian host, rendering its study of fundamental importance for the understanding of the disease. It was not possible to obtain the recombinant expression of any of the two viral proteins, therefore we established a new protocol for cell lysis and purification with which it was obtained unprecedented images of Transmission electron microscopy. In the present proposal we will continue the work previously initiated with more detailed investigation of Scaning electron Microscopy by Negative Staining technique and Cryo-Electron Microscopy. This work will allow the establishment of a structural model of the LRV1-4 capsid arrangement and so establish its correct relation among the Totiviridae. In addition to the biological and Leishmania pathogenesis contributions of this study, it represents also the first structural characterization of a viral capsid undertaken in Brasil and therefore an important contribution to the virology and structural biology fields in Brasil. (AU)