RIN4 interacts with Pseudomonas syringae type III effector molecules and is required for RPM1-mediated resistance in Arabidopsis.
In Arabidopsis, RPM1 confers resistance against Pseudomonas syringae expressing either of two sequence unrelated type III effectors, AvrRpm1 or AvrB. An RPM1-interacting protein (RIN4) coimmunoprecipitates from plant cell extracts with AvrB, AvrRpm1, or RPM1. Reduction of RIN4 protein levels inhibits both the hypersensitive response and the restriction of pathogen growth controlled by RPM1. RIN4 reduction causes diminution of RPM1. RIN4 reduction results in heightened resistance to virulent Peronospora parasitica and P. syringae, and ectopic defense gene expression. Thus, RIN4 positively regulates RPM1-mediated resistance yet is, formally, a negative regulator of basal defense responses. AvrRpm1 and AvrB induce RIN4 phosphorylation. This may enhance RIN4 activity as a negative regulator of plant defense, facilitating pathogen growth. RPM1 may "guard" against pathogens that use AvrRpm1 and AvrB to manipulate RIN4 activity.
Mackey
David
D
Department of Biology, University of North Carolina, Chapel Hill, NC 27599, USA.
Holt
Ben F
BF
Wiig
Aaron
A
Dangl
Jeffery L
JL
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development / Q000382:microbiology; D029681:Arabidopsis Proteins / Q000032:analysis / Q000235:genetics* / Q000378:metabolism; D001426:Bacterial Proteins / Q000378:metabolism; D001483:Base Sequence; D002352:Carrier Proteins / Q000032:analysis / Q000235:genetics* / Q000378:metabolism; D002458:Cell Fractionation; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D007113:Immunity, Innate / Q000235:genetics; D047908:Intracellular Signaling Peptides and Proteins; D008969:Molecular Sequence Data; D010766:Phosphorylation; D010935:Plant Diseases / Q000235:genetics* / Q000382:microbiology; D010940:Plant Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified; D011549:Pseudomonas / Q000254:growth & development / Q000378:metabolism* / Q000472:pathogenicity; D014774:Virulence / Q000235:genetics
D029681:Arabidopsis Proteins; C100931:AvrB protein, Pseudomonas syringae; D001426:Bacterial Proteins; D002352:Carrier Proteins; D047908:Intracellular Signaling Peptides and Proteins; D010940:Plant Proteins; C453279:RIN4 protein, Arabidopsis; C095014:RPM1 protein, Arabidopsis