Objective
This proposal is concerned with molecular mechanisms of translation initiation directed by Internal Ribosomal Entry Sites (IRES) of foot-and-mouth disease virus (FMDV) and encephalomyocarditis virus (EMCV) RNAs. The replication of these and other picornaviruses occurs exclusively in the cytoplasm of the mammalian cell and, hence, the translation of picornaviral genomic RNAs is the very first event in their replication. The IRES-elements of picornaviral RNAs (~450nt long) are specific features of picornaviral RNAs that allow them to successfully compete for the cellular translational apparatus with the bulk of host mRNAs at the beginning of infection of mammalian cells.
In this project, attention will be focused on those structural domains of the FMDV and EMCV IRESs whose functions are still unknown and, therefore, prevents us from understanding how these IRESs work. The principal experimental procedures to reach the goals of the project are:
1) footprinting assays to identify sites of interaction of the translational components with the IRESs;
2) crosslinking of chemically modified IRESs (with affinity labels at selected points) to components of the translation initiation apparatus and intramolecular crosslinking of these modified nucleotides to other domains of the IRESs and ;
3) in vitro translation directed by mRNAs containing various mutant EMCV/FMDV IRESs in HeLa cell extracts as a novel system to study the functional roles of separate domains of the IRESs.
The project should result in a better understanding of the functional topography of IRES-elements of picornavirus RNAs, exemplified by EMCV and FMDV RNAs. The data are anticipated to substantially clarify the issue of how picornavirus IRESs works. This should be of great assistance for the elaboration of new ways to fight important picornavirus infections.
Topic(s)
Call for proposal
Data not availableFunding Scheme
Data not availableCoordinator
GU24 ONF Woking
United Kingdom