The coiled-coil and nucleotide binding domains of the Potato Rx disease resistance protein function in pathogen recognition and signaling

Plant Cell. 2008 Mar;20(3):739-51. doi: 10.1105/tpc.107.056036. Epub 2008 Mar 14.

Abstract

Plant genomes encode large numbers of nucleotide binding and leucine-rich repeat (NB-LRR) proteins, some of which mediate the recognition of pathogen-encoded proteins. Following recognition, the initiation of a resistance response is thought to be mediated by the domains present at the N termini of NB-LRR proteins, either a Toll and Interleukin-1 Receptor or a coiled-coil (CC) domain. In order to understand the role of the CC domain in NB-LRR function, we have undertaken a systematic structure-function analysis of the CC domain of the potato (Solanum tuberosum) CC-NB-LRR protein Rx, which confers resistance to Potato virus X. We show that the highly conserved EDVID motif of the CC domain mediates an intramolecular interaction that is dependent on several domains within the rest of the Rx protein, including the NB and LRR domains. Other conserved and nonconserved regions of the CC domain mediate the interaction with the Ran GTPase-activating protein, RanGAP2, a protein required for Rx function. Furthermore, we show that the Rx NB domain is sufficient for inducing cell death typical of hypersensitive plant resistance responses. We describe a model of CC-NB-LRR function wherein the LRR and CC domains coregulate the signaling activity of the NB domain in a recognition-specific manner.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Amino Acid Motifs
  • Amino Acid Sequence
  • Binding Sites / genetics
  • Gene Silencing
  • Immunity, Innate / genetics
  • Molecular Sequence Data
  • Mutagenesis, Site-Directed
  • Mutation
  • Plant Diseases / genetics
  • Plant Diseases / virology
  • Plant Proteins / chemistry
  • Plant Proteins / genetics*
  • Plant Proteins / metabolism
  • Polymerase Chain Reaction
  • Potexvirus / growth & development*
  • Protein Binding
  • Protein Structure, Tertiary
  • Proteins / genetics
  • Proteins / metabolism
  • Signal Transduction*
  • Solanum tuberosum / genetics*
  • Solanum tuberosum / metabolism
  • Solanum tuberosum / virology

Substances

  • Plant Proteins
  • Proteins
  • leucine-rich repeat proteins