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.
Moffett
Peter
P
The Sainsbury Laboratory, John Innes Centre, Norwich Research Park, Colney, Norwich NR4 7UH, UK.
Farnham
Garry
G
Peart
Jack
J
Baulcombe
David C
DC
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