@article{013041c4112a4a55b97519a272ec3cab,
title = "A type III effector ADP-ribosylates RNA-binding proteins and quells plant immunity",
abstract = "The bacterial plant pathogen Pseudomonas syringae injects effector proteins into host cells through a type III protein secretion system to cause disease. The enzymatic activities of most of P. syringae effectors and their targets remain obscure. Here we show that the type III effector HopU1 is a mono-ADP-ribosyltransferase (ADP-RT). HopU1 suppresses plant innate immunity in a manner dependent on its ADP-RT active site. The HopU1 substrates in Arabidopsis thaliana extracts were RNA-binding proteins that possess RNA-recognition motifs (RRMs). A. thaliana knockout lines defective in the glycine-rich RNA-binding protein GRP7 (also known as AtGRP7), a HopU1 substrate, were more susceptible than wild-type plants to P. syringae. The ADP-ribosylation of GRP7 by HopU1 required two arginines within the RRM, indicating that this modification may interfere with GRP7's ability to bind RNA. Our results suggest a pathogenic strategy where the ADP-ribosylation of RNA-binding proteins quells host immunity by affecting RNA metabolism and the plant defence transcriptome.",
author = "Fu, {Zheng Qing} and Ming Guo and Jeong, {Byeong Ryool} and Fang Tian and Elthon, {Thomas E.} and Cerny, {Ronald L.} and Dorothee Staiger and Alfano, {James R.}",
note = "Funding Information: Acknowledgements We thank the members of the Alfano laboratory for many fruitful discussions, Y. Zhou and C. Elowsky for technical assistance with confocal microscopy, T. Clemente and S. Sato for constructing transgenic plants, G. Li and C. Bryan for assistance in the identification of the A. thaliana grp7 mutants, A. Collmer for reviewing the manuscript, P. Seitz for assistance in plasmid constructions, and J. T. Barbieri for help initiating the ADP-RT assays in our laboratory. We are grateful to the Ohio State University Arabidopsis Biological Resource Center, the Salk Institute Genomic Analysis Laboratory, and the Arabidopsis research community for providing the Arabidopsis SALK lines used in this study. This research was supported by grants from the National Science Foundation and the National Institutes of Health, and funds from the Plant Science Initiative at the University of Nebraska to J.R.A, and a grant from the German Research Council to D.S.",
year = "2007",
month = may,
day = "17",
doi = "10.1038/nature05737",
language = "English (US)",
volume = "447",
pages = "284--288",
journal = "Nature",
issn = "0028-0836",
publisher = "Nature Publishing Group",
number = "7142",
}