A type III effector ADP-ribosylates RNA-binding proteins and quells plant immunity

Zheng Qing Fu, Ming Guo, Byeong Ryool Jeong, Fang Tian, Thomas E. Elthon, Ronald L. Cerny, Dorothee Staiger, James R. Alfano

Research output: Contribution to journalArticle

245 Scopus citations

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.

Original languageEnglish (US)
Pages (from-to)284-288
Number of pages5
JournalNature
Volume447
Issue number7142
DOIs
StatePublished - May 17 2007

ASJC Scopus subject areas

  • General

Fingerprint Dive into the research topics of 'A type III effector ADP-ribosylates RNA-binding proteins and quells plant immunity'. Together they form a unique fingerprint.

  • Cite this

    Fu, Z. Q., Guo, M., Jeong, B. R., Tian, F., Elthon, T. E., Cerny, R. L., Staiger, D., & Alfano, J. R. (2007). A type III effector ADP-ribosylates RNA-binding proteins and quells plant immunity. Nature, 447(7142), 284-288. https://doi.org/10.1038/nature05737