Interaction between plant viruses and the Ubiquitin-Proteasome System

The ubiquitin-proteasome system (UPS) is the primary eukaryotic pathway for selective protein degradation and plays a central role in various cellular processes, including plant immunity and antiviral defense.

The UPS is a double-edged sword as it provides important services to viral infections but likewise is part of orchestrating a proper immune response, both driving virus evolution towards UPS manipulation and exploitation. Despite this exiting constellation, the interplay between UPS and plant viruses has remained poorly studied.

Along increased globalization in agriculture and the ongoing climate change, new viral diseases affecting various crops have emerged globally with negative socioeconomic impacts. The VIRUPS project will be conducted at the Swedish University of Agricultural Sciences (SLU) under Dr. Hafrn's supervision, aiming to address the knowledge gap in the UPS-virus interplay in plants.

Our preliminary data shows that plant viruses enhance proteasome activity and induce different changes to UPS components and ubiquitination, together conveying a detailed response of the UPS to viruses.

The project will characterize plant ubiquitinome dynamics upon infection with three different viruses in comparative virology to identify virus common and specific responses with details on differentially ubiquitinated proteins (DUPs) and targeted cellular pathways.

A parallel approach will exploit one of our viruses (CaMV) capacity to activate the proteasome, because this phenotype shows wide variation among Arabidopsis natural accessions.

This offers an exceptional opportunity to address correlations between proteasome activation and various disease intensity parameters, in addition to forming the basis for a genome-wide association study (GWAS) for identifying UPS regulators.

UPS regulators, components, and targets obtained through this diverse set of approaches, will fuel the discovery of novel UPS-related mechanisms in disease and crop protection strategies.