NRG1, a CC-NB-LRR protein, together with N, a TIR-NB-LRR protein, mediates resistance against tobacco mosaic virus

Curr Biol. 2005 May 24;15(10):968-73. doi: 10.1016/j.cub.2005.04.053.

Abstract

In animals and plants, innate immunity is regulated by nucleotide binding domain and leucine-rich repeat (NB-LRR) proteins that mediate pathogen recognition and that activate host-cell defense responses. Plant NB-LRR proteins, referred to as R proteins, have amino-terminal domains that contain a coiled coil (CC) or that share similarity with animal Toll and interleukin 1 receptors (TIR). To investigate R protein function, we are using the TIR-NB-LRR protein N that mediates resistance against tobacco mosaic virus (TMV) through recognition of the TMV p50 protein. Here, we describe N requirement gene 1 (NRG1), a novel N-resistance component that was identified by a virus-induced gene silencing (VIGS) screen of a cDNA library. Surprisingly, NRG1 encodes an NB-LRR type R protein that, in contrast to N, contains a CC rather than a TIR domain. Our findings support emerging evidence that many disease-resistance pathways each recruit more than a single NB-LRR protein. The results also indicate that, in addition to the previously recognized role in elicitor recognition, NB-LRR proteins may also function in downstream signaling pathways.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Cloning, Molecular
  • DNA, Complementary / genetics
  • Gene Components
  • Gene Library
  • Gene Silencing
  • Immunity, Innate / immunology*
  • Molecular Sequence Data
  • Nucleic Acid Amplification Techniques
  • Plant Diseases / virology*
  • Plant Proteins / genetics*
  • Plant Proteins / immunology
  • Plants, Genetically Modified
  • Signal Transduction / immunology*
  • Tobacco / immunology*
  • Tobacco / virology
  • Tobacco Mosaic Virus*

Substances

  • DNA, Complementary
  • Plant Proteins