A Host Protein Interacting With a Tombusvirus Cell-to-Cell Movement Protein

Texas A&M Research Foundation, College Station TX

Investigators

Abstract

Viruses are suitable tools to study trafficking of macromolecules through plants because they encode specialized movement proteins (MPs) that enable these pathogens to move cell to cell via the plasmodesmata. Moreover, the MP encoded by the single-stranded positive-sense RNA genome of Tomato bushy stunt virus (TBSV) is functional in many different families. Recent data have shown that the TBSV MP interacts with a novel host factor (HF3.5) with similarities to a class of transcription factors that are known to traffic through plasmodesmata. Results of in vivo and in vitro binding tests with defined MP mutants provided support for the hypothesis that the interaction between HF3.5 and the TBSV MP is functionally relevant. The objectives of this project aim to further test this hypothesis by: I) a detailed molecular analysis of the P22-HF3.5 interaction, II) localization of the HF3.5 protein in planta, III) biochemical verification of P22-host protein interactions in plant extracts, and IV) studying the functional role by monitoring the effect of HF3.5 gene silencing on TBSV movement and infection. It is anticipated that the studies of this newly described movement-associated host protein will provide novel insights into the interactions that control movement of viruses and other macromolecules through plants.