Maturation, a critical process in the infection cycle of viruses, plays a serious role for all animal and bacterial viruses and is required to produce infectious virions or particles. Though the outlines of the process have been determined for many groups of viruses, detailed mechanistic studies have not been reported.
To provide the first detailed mechanistic study of maturation, Roger Castells-Graells inserted genetic material of the insect virus Nudaurelia capensis omega into dwarf tobacco plants N.benthamiana. This transient expression technique uses virus-like particles (VLPs) that mimic of the authentic virus. The research demonstrated that maturation of procapsids—immature viral structures—can occur within plant cells to yield fully functional mature capsids. This has not been observed previously in the absence of a natural infection and is a new application for the transient expression system pioneered by Professor Lomonossoff at the John Innes Centre. The study was published in the journal Communications Biology.
"Most structural studies of virus particles to date have given a static picture of the particles. By isolating particles from plants that are undergoing the process of maturation, we have managed to obtain a picture of the dynamics of an essential part of a virus infection cycle,” said Lomonossoff.
What is now required is an analysis of intermediate steps to get a complete understanding of the dynamics. This will enable the research team to determine the 3-D structures of intermediates in the maturation process to create a movie that they are hoping will be of interest to potential collaborators in the industry.
Photo: Virus Like Particles are mimics of the Nudaurelia capensis omega virus a model used to provide dynamic details about the process of viral maturation. Credit: Roger Castells-Graells