Special Ks – doping RPM1 activity
F. EL KASMI (1), R. Anderson (1), E. Chung (1), J. Dangl (1) (1) University of North Carolina, U.S.A.

One of the best characterized nucleotide binding-leucine-rich repeat (NLR) immune receptors in plants is the CC-NLR RPM1. RPM1 localizes to the plasma membrane where it is interacting with and guarding the small host protein RIN4 (RPM1 interacting protein 4). RIN4 functions as a molecular switch in the two tiered innate immune system of Arabidopsis and is target by at least three different pathogen-derived effector proteins. RPM1 is activated by an effector-mediated increase of phosphorylation of threonine 166 on RIN4 and its activation eventually leads to a programmed host cell death, called the hypersensitive response (HR) or effector-triggered immunity (ETI). The exact mechanisms by which RPM1 senses the phosphorylation event on RIN4 and how this recognition activates RPM1 are still unknown. We identified new gain of function and loss of function RPM1 mutants through a targeted site-directed mutagenesis of charged residues in the RPM1 CC and NLR domain, the domains demonstrated to be important for RPM1-RIN4 interaction. We present a possible mechanism explaining how alterations in intramolecular domain interactions of RPM1 are leading to its activation and how RPM1 senses the phosphorylation of RIN4 T166.

Abstract Number: P17-518
Session Type: Poster