Pseudomonas HopU1 modulates plant immune receptor levels by blocking the interaction of their mRNAs with GRP7

Authors

Valerie Nicaise, The Sainsbury Laboratory, Norwich Research Park, Norwich, UK
Anna Joe, University of Nebraska-Lincoln
Byeong-Ryool Jeong, University of Nebraska - LincolnFollow
Christin Korneli, University of Bielefeld, Germany
Freddy Boutrot, The Sainsbury Laboratory, Norwich Research Park, Norwich, UK
Isa Westedt, The Sainsbury Laboratory, Norwich Research Park, Norwich, UK
Dorothee Staiger, University of Bielefeld, Germany
James R. Alfano, University of Nebraska-LincolnFollow
Cyril Zipfel, The Sainsbury Laboratory, Norwich Research Park, Norwich, UKFollow

Document Type

Article

Date of this Version

3-2013

Citation

EMBO J. 32(5): 701-712. DOI: 10.1038/emboj.2013.15

Comments

Copyright © 2013, European Molecular Biology Organization. Used by permission.

Abstract

Pathogens target important components of host immunity to cause disease. The Pseudomonas syringae type III-secreted effector HopU1 is a mono-ADP-ribosyltransferase required for full virulence on Arabidopsis thaliana. HopU1 targets several RNA-binding proteins including GRP7, whose role in immunity is still unclear. Here, we show that GRP7 associates with translational components, as well as with the pattern recognition receptors FLS2 and EFR. Moreover, GRP7 binds specifically FLS2 and EFR transcripts in vivo through its RNA recognition motif. HopU1 does not affect the protein–protein associations between GRP7, FLS2 and translational components. Instead, HopU1 blocks the interaction between GRP7 and FLS2 and EFR transcripts in vivo. This inhibition correlates with reduced FLS2 protein levels upon Pseudomonas infection in a HopU1- dependent manner. Our results reveal a novel virulence strategy used by a microbial effector to interfere with host immunity.