A novel class of eukaryotic zinc-binding proteins is required for disease resistance signaling in barley and development in C. elegans.
Barley Rar1 is a convergence point in the signaling of resistance to powdery mildew, triggered by multiple race-specific resistance (R) genes. Rar1 is shown to function upstream of H2O2 accumulation in attacked host cells, which precedes localized host cell death. We isolated Rar1 by map-based cloning. The sequence of the deduced 25.5 kDa protein reveals two copies of a 60-amino acid domain, CHORD, conserved in tandem organization in protozoa, plants, and metazoa. CHORD defines a novel eukaryotic Zn2+-binding domain. Silencing of the C. elegans CHORD-containing gene, chp, results in semisterility and embryo lethality, suggesting an essential function of the wild-type gene in nematode development. Our findings indicate that plant R genes have recruited a fundamental cellular control element for signaling of disease resistance and cell death.
Shirasu
K
K
The Sainsbury Laboratory, John Innes Centre, Norwich, United Kingdom.
Lahaye
T
T
Tan
M W
MW
Zhou
F
F
Azevedo
C
C
Schulze-Lefert
P
P
D000483:Alleles; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D017173:Caenorhabditis elegans / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D002352:Carrier Proteins / Q000145:classification / Q000235:genetics / Q000502:physiology*; D016923:Cell Death; D003001:Cloning, Molecular; D018076:DNA, Complementary; D004331:Drosophila melanogaster / Q000235:genetics; D005057:Eukaryotic Cells; D017343:Genes, Plant; D001467:Hordeum / Q000235:genetics / Q000502:physiology*; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism; D047908:Intracellular Signaling Peptides and Proteins; D008969:Molecular Sequence Data; D009154:Mutation; D010935:Plant Diseases; D010940:Plant Proteins; D012326:RNA Splicing; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction; D014122:Toxoplasma / Q000235:genetics; D014158:Transcription, Genetic; D015032:Zinc
D002352:Carrier Proteins; D018076:DNA, Complementary; D047908:Intracellular Signaling Peptides and Proteins; D010940:Plant Proteins; C499582:Rar1 protein, Hordeum vulgare; D006861:Hydrogen Peroxide; D015032:Zinc