An Investigation of RIN4 Phosphorylation in Plant Immunity

Undergraduate #205
Discipline: Chemistry and Chemical Sciences
Subcategory: Plant Research

Elizabeth Umanah - University of Georgia

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RPM-Interacting Protein 4 (RIN4) is an essential regulator of plant defense in the model Arabidopsis-Pseudomonas pathosystem. This protein performs its role by activating both effector- and pathogen-associated molecular patterns (PAMP)-triggered immunity (ETI and PTI) by being phosphorylated. Current work in our lab has identified two kinases that interact with RIN4. The research being conducted seeks to understand the mechanisms behind the interaction of each kinase with RIN4 by examining if phosphorylation will occur at specific residues on the protein. It was hypothesized that elimination of RIN4 phosphorylation will inactivate its immune signaling function, rendering plants susceptible to pathogen infection. The research will be conducted by first performing an in-vitro kinase assay. Then, to elucidate the role of RIN4 phosphorylation, we will assess the presence of the hypersensitive response (HR) by co-infiltrating a bacterial effector and RIN4 phosphomimetic proteins into the plant Nicotiana benthamiana. The results of the experiment will allow us to understand how these two kinases interact with RIN4 to elicit the plant’s defensive functions against an infection. With the knowledge from the results, the mechanism behind RIN4’s plant immune regulation and the protein’s significance during the regulation will be determined.

Funder Acknowledgement(s): The National Science Foundation and Michigan State University

Faculty Advisor: Brad Day, bday@msu.edu

Role: Under the guidance of my mentor, Yi-Ju Lu, I performed the in-vitro kinase assay, the site directed mutagenesis to create the 4 phosphomimetics, and the co-infiltration of the bacterial effector and each phosphomimetic into the N. benthamiana plant.