Identification of a host 14-3-3 protein that interacts with Xanthomonas effector AvrRxv

• Published in: Physiological and molecular plant pathology Vol. 72; no. 1; pp. 46 - 55
• Main Authors: Whalen, Maureen C., Richter, Todd, Zakhareyvich, Kseniya, Yoshikawa, Masayasu, Al-Azzeh, Dana, Adefioye, Adeshola, Spicer, Greg, Mendoza, Laura L., Morales, Christine Q., Klassen, Vicki, Perez-Baron, Gina, Toebe, Carole S., Tzovolous, Ageliki, Gerstman, Emily, Evans, Erika, Thompson, Cheryl, Lopez, Mary, Ronald, Pamela C.
• Format: Journal Article
• Language: English
• Published: London Elsevier India Pvt Ltd 01-01-2008; Elsevier
• Subjects: 14-3-3 protein; Agrobacterium; Avirulence protein; bacterial proteins; Biological and medical sciences; Effector; Fundamental and applied biological sciences. Psychology; host-pathogen relationships; Hypersensitive response (HR); Lycopersicon esculentum; Phytopathology. Animal pests. Plant and forest protection; plant proteins; protein-protein interactions; Solanum esculentum; Solanum lycopersicum var. lycopersicum; tomatoes; transcription initiation site; Xanthomonas; Xanthomonas campestris; Xanthomonas campestris pv. vesicatoria; Yeast two-hybrid interaction screen; Yersinia; Yersinia enterocolitica; Yersinia enterocolitica; Xanthomonas campestris pv. vesicatoria; Avirulence protein; Yeast two-hybrid interaction screen; Hypersensitive response (HR); Effector; Solanum esculentum; Plant pathology
• ISSN: 0885-5765; 1096-1178; 1096-1178
• DOI: 10.1016/j.pmpp.2008.05.006

AvrRxv is a member of a family of pathogen effectors present in pathogens of both plant and mammalian species.
Xanthomonas campestris pv.
vesicatoria strains carrying AvrRxv induce a hypersensitive response (HR) in the tomato cultivar Hawaii 7998. Using a yeast two-hybrid screen, we identified a 14-3-3 protein from tomato that interacts with AvrRxv called
Avr
Rxv interactor 1 (ARI1). The interaction was confirmed
in vitro with affinity chromatography. Using mutagenesis, we identified a 14-3-3-binding domain in AvrRxv and demonstrated that a mutant in that domain showed concomitant loss of interaction with ARI1 and HR-inducing activity in tomato. These results demonstrate that the AvrRxv bacterial effector recruits 14-3-3 proteins for its function within host cells. AvrRxv homologues YopP and YopJ from
Yersinia do not have AvrRxv-specific HR-inducing activity when delivered into tomato host cells by
Agrobacterium. Although YopP itself cannot induce HR, its C-terminal domain containing the catalytic residues can replace that of AvrRxv in an AvrRxv-YopP chimera for HR-inducing activity. Phylogenetic analysis indicates that the sequences encoding the C-termini of family members are evolving independently from those encoding the N-termini. Our results support a model in which there are three functional domains in proteins of the family: translocation, interaction, and catalytic.