Interaction between domains of a plant NBS-LRR protein in disease resistance-related cell death.
Many plant disease resistance (R) genes encode proteins predicted to have an N-terminal coiled-coil (CC) domain, a central nucleotide-binding site (NBS) domain and a C-terminal leucine-rich repeat (LRR) domain. These CC-NBS-LRR proteins recognize specific pathogen-derived products and initiate a resistance response that often includes a type of cell death known as the hypersensitive response (HR). Co-expression of the potato CC-NBS-LRR protein Rx and its elicitor, the PVX coat protein (CP), results in a rapid HR. Surprisingly, co-expression of the LRR and CC-NBS as separate domains also resulted in a CP-dependent HR. Likewise, the CC domain complemented a version of Rx lacking this domain (NBS- LRR). Correspondingly, the LRR domain interacted physically in planta with the CC-NBS, as did CC with NBS-LRR. Both interactions were disrupted in the presence of CP. However, the interaction between CC and NBS-LRR was dependent on a wild-type P-loop motif, whereas the interaction between CC-NBS and LRR was not. We propose that activation of Rx entails sequential disruption of at least two intramolecular interactions.
The Sainsbury Laboratory, John Innes Centre, Norwich Research Park, Colney, Norwich NR4 7UH, UK.
Peter
P
Moffett
Garry
G
Farnham
Jack
J
Peart
David C
DC
Baulcombe
D020816:Amino Acid Motifs; D002213:Capsid / Q000737:chemistry / Q000378:metabolism; D036022:Capsid Proteins; D020868:Gene Silencing; D005816:Genetic Complementation Test; D007113:Immunity, Innate / Q000235:genetics; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism; D010940:Plant Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D017863:Potexvirus / Q000378:metabolism; D011487:Protein Conformation; D025941:Protein Interaction Mapping; D017434:Protein Structure, Tertiary; D011198:Solanum tuberosum / Q000235:genetics / Q000378:metabolism* / Q000821:virology
D036022:Capsid Proteins; D010446:Peptide Fragments; D010940:Plant Proteins; C120017:Rx protein, Solanum tuberosum; C058750:coat protein, Potato virus X