Engineering an auto-activated R protein that is in vivo activated by a viral protease

• Published in: Virology (New York, N.Y.) Vol. 510; pp. 242 - 247
• Main Authors: Tran, Phu-Tri, Widyasari, Kristin, Park, Jee Yoon, Kim, Kook-Hyung
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.10.2017
• Subjects: amino acid substitution; Disease Resistance; genes; hypersensitive response; NIa-dependent HR; Nicotiana - virology; Peptide Hydrolases - metabolism; peptides; Plant Diseases - prevention & control; Plant Diseases - virology; Plant Proteins - genetics; Plant Proteins - metabolism; Plants, Genetically Modified - virology; Potyvirus; Potyvirus - immunology; Potyvirus - pathogenicity; Protein Engineering; protein synthesis; proteinases; proteins; Pvr9; Recombinant Fusion Proteins - genetics; Recombinant Fusion Proteins - metabolism; Self-HR; Virus resistance; NIa-dependent HR; Virus resistance; Potyvirus; Pvr9; Self-HR
• ISSN: 0042-6822; 1096-0341; 1096-0341
• DOI: 10.1016/j.virol.2017.07.020

Autonomous hypersensitive responses (self-HRs) are caused by constitutively active R proteins. In this study, we identified an auto-activated form of the R gene Pvr9 (autoPvr9); the auto-activation results from an amino acid substitution between its NBS and LRR domains. Self-HR was strongly reduced or completely inhibited by fusion of an extra peptide to the autoPvr9 N-terminal or C-terminal, respectively. When an NIa recognition site was placed between autoPvr9 and the extra peptide, the fusion construct could trigger an NIa-dependent HR. Several C-terminal fusions were tested, but only those that maintained detectable protein expression were capable of an NIa-dependent HR. Our results suggest the potential for transforming malfunctioning and auto-activated R proteins into a new construct targeting potyviral NIa proteases. •Mutations at position 988 between NBS and LRR domains converted Pvr9 to an auto-activated form.•Extra residues at both ends of autoPvr9 inhibited the auto-activated state of autoPvr9.•NIa-mediated cleavage of the fusion domain from autoPvr9 triggered a hypersensitive response.