Antagonistic control of disease resistance protein stability in the plant immune system.
Pathogen recognition by the plant immune system is governed by structurally related, polymorphic products of disease resistance (R) genes. RAR1 and/or SGT1b mediate the function of many R proteins. RAR1 controls preactivation R protein accumulation by an unknown mechanism. We demonstrate that Arabidopsis SGT1b has two distinct, genetically separable functions in the plant immune system: SGT1b antagonizes RAR1 to negatively regulate R protein accumulation before infection, and SGT1b has a RAR1-independent function that regulates programmed cell death during infection. The balanced activities of RAR1 and SGT1, in concert with cytosolic HSP90, modulate preactivation R protein accumulation and signaling competence.
Holt
Ben F
BF
Department of Biology, University of North Carolina, Chapel Hill, NC 27599, USA.
Belkhadir
Youssef
Y
Dangl
Jeffery L
JL
D017209:Apoptosis; D017360:Arabidopsis / Q000276:immunology* / Q000382:microbiology; D029681:Arabidopsis Proteins / Q000235:genetics / Q000276:immunology / Q000502:physiology*; D002352:Carrier Proteins / Q000037:antagonists & inhibitors / Q000276:immunology / Q000502:physiology*; D018797:Cell Cycle Proteins / Q000276:immunology / Q000502:physiology*; D017343:Genes, Plant; D018841:HSP90 Heat-Shock Proteins / Q000276:immunology / Q000502:physiology; D047908:Intracellular Signaling Peptides and Proteins; D009154:Mutation; D044742:Peronospora / Q000502:physiology; D010935:Plant Diseases / Q000382:microbiology; D010940:Plant Proteins / Q000037:antagonists & inhibitors / Q000276:immunology / Q000502:physiology*; D030821:Plants, Genetically Modified; D015398:Signal Transduction
D029681:Arabidopsis Proteins; D002352:Carrier Proteins; D018797:Cell Cycle Proteins; D018841:HSP90 Heat-Shock Proteins; D047908:Intracellular Signaling Peptides and Proteins; C499581:PBS2 protein, Arabidopsis; D010940:Plant Proteins; C107295:RPP5 protein, Arabidopsis; C488787:RPP8 protein, Arabidopsis; C465630:RPS5 protein, Arabidopsis; C452192:SGT1b protein, Arabidopsis