Genome Organisation, Translation and Replication of Foot-and-mouth Disease Virus RNA
Encarnacion Martinez-Salas and Graham J. Belsham
from: Foot-and-Mouth Disease Virus: Current Research and Emerging Trends (Edited by: Francisco Sobrino and Esteban Domingo). Caister Academic Press, U.K. (2017) Pages: 13-42.
Foot-and-mouth disease virus (FMDV), a picornavirus, has a positive-sense RNA genome that encodes a large polyprotein. The intact polyprotein is never observed; it is co- and post-translationally processed, largely by virus-encoded proteases, to produce 15 different mature proteins plus a variety of precursors. The RNA genome also has to act as the template for RNA replication. This process occurs in two stages. Initially, synthesis of negative strands occurs using the positive strand template and then the production of many positive-sense infectious RNAs is achieved from the negative strands. The infectious RNAs are then packaged by the capsid proteins to produce new virus particles. Particular emphasis in this review is placed on the role of distinct RNA structures within the viral genome in the initiation of protein synthesis and in the initiation of RNA replication. Early on in FMDV-infected cells, the synthesis of host cell proteins is inhibited, due to modification of the cellular translation machinery that is induced by a virus-encoded protease. However, viral protein synthesis is maintained under these conditions. Replication of the viral RNA is achieved by the virus encoded RNA-dependent RNA polymerase within replication complexes assembled within the cytoplasm of the cell. Thus both viral RNA and viral protein production are dependent on the functions of virus-encoded proteins and conserved RNA structures read more ...