|CHAVEZ, JUAN - University Of Washington|
|ALEXANDER, MARIKO - Cornell University|
|Ramsey, John - John|
|ENG, JIMMY - University Of Washington|
|MAHONEY, JACLYN - Cornell University|
|BRUCE, JAMES - University Of Washington|
Submitted to: Journal of Virology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/9/2015
Publication Date: 12/9/2015
Citation: Deblasio, S.L., Chavez, J., Alexander, M., Ramsey, J.S., Eng, J., Mahoney, J., Gray, S.M., Bruce, J., Cilia, M. 2015. Visualization of host-polerovirus interaction topologies using Protein Interaction Reporter technology. Journal of Virology. 90:1973-1987.
Interpretive Summary: The exterior shape of a plant virus and its interacting host and insect vector proteins determine whether a virus will be transmitted by an insect and infect a specific host. Gaining this information is difficult and requires years of experimentation. We used Protein Interaction Reporter (PIR) technology to illustrate how viruses exploit host proteins during plant infection. PIR technology enabled our team to precisely describe the sites of functional virus-virus, virus-host, and host-host protein interactions using a mass spectrometry analysis that takes just a few hours. Applications of PIR technology in host-pathogen interactions will enable researchers studying recalcitrant pathogens, such as animal pathogens where host proteins are incorporated directly into the infectious agents, to investigate how proteins interact during infection and transmission and to develop new tools for interdiction and therapy.
Technical Abstract: Demonstrating direct interactions between host and virus proteins during infection is a major goal and challenge for the field of virology. The majority of interactions are not binary or easily amenable to structural determination. Using infectious preparations of a polerovirus (Potato leafroll virus, PLRV) and Protein Interaction Reporter (PIR), a technology that couples a mass spectrometric-cleavable chemical cross-linker with high resolution mass spectrometry, we provide the first report of any host-pathogen protein interaction network that includes data-derived, topological features for every cross-linked site that was identified. We show that PLRV virions have hot spots of protein interaction and multifunctional surface topologies, revealing how these plant viruses maximize their use of protein interaction interfaces. Modeling data, guided by cross-linking constraints, suggest asymmetric packing of the major capsid protein in the virion in line with previous epitope mapping studies. Protein interaction topologies are conserved with other species in the Luteoviridae and with unrelated viruses in the Herpesviridae and Adenoviridae. A functional analysis of four PLRV-interacting host proteins in planta using a reverse genetics approach revealed a complex, molecular tug-of-war between host and virus. Structural mimicry and diversifying selection - hallmarks of host-pathogen interactions - were identified within host and viral binding interfaces. These results illuminate the functional diversity of the PLRV-host protein interaction network and demonstrate the usefulness of PIR technology for precision mapping of functional host-pathogen protein interaction topologies.