P-234 - Characterization of novel geminiviral genes uncovers new virulence strategies

Viruses are intracellular parasites with limited coding capacity that dramatically manipulate their host cell. How viruses can subvert the cell with only a handful of proteins remains largely enigmatic. Geminiviruses, which infect a large variety of crop species and lead to enormous losses in yield worldwide, have a small-sized genome, fully relying on the host molecular machinery. Members of this family therefore constitute an excellent model to comprehensively study the viral manipulation of the host cell. Here, we aim to map the molecular intersection between virus and infected cell with unprecedented resolution. Screening the genome of three different geminiviruses (tomato yellow leaf curl virus, beet curly top virus, and chickpea chlorotic dwarf virus), we have identified additional protein-coding genes with virulence functions. The corresponding novel viral proteins are identified through proteomics, integrated in the viral protein-protein interaction network, and contribute to the viral infection. Our results unveil that the geminiviral proteome and its intersection with the host cell are much larger than previously thought. We anticipate that our findings will provide novel insight into the strategies evolved by geminiviruses to manipulate their hosts, establishing a novel framework for the study of virus-host interactions.