Investigate the regulation of Mitogen-activated protein Kinase Phosphatase 1 (MKP1) in PAMP signaling and resistance to bacteria
L. JIANG (1), Y. Wan (1), J. Anderson (2), R. Ulm (3), S. Peck (2) (1) University of Missouri-Columbia, U.S.A.; (2) University of Missouri-Columbia, U.S.A.; (3) University of Geneva, Switzerland

The perception of pathogens starts with recognition of conserved pathogen-associated molecular patterns (PAMPs). PAMP responses include changes in intracellular protein phosphorylation, including activation of mitogen-activated protein kinases (MAPKs) cascades. MAP kinase phosphatases (MKPs) are important negative regulators of MAPKs. Work with non-plant organisms has shown that MAPKs control their own negative regulators. In plants, Arabidopsis MKP1 was shown to be a negative regulator of innate immune signaling, and phosphorylation was also suggested to be an important mechanism for regulating MKP1. The result that phosphorylation site mutants were not able to complement most mkp1 phenotypes, indicating that phosphorylation of those sites is required for the function of MKP1. One hypothesis is that MKP1 is phosphorylated in response to PAMP treatment and that phosphorylation stabilizes the protein. This supposition is supported by the result that both PAMP and MG132 treatments increased MKP1 protein level. In addition, to investigate the possible roles of distinct structural subdomains in the function of MKP1, domain truncation mutants were generated. Preliminary results indicate that the gelsolin but not the camodulin binding domains are required for the function of MKP1. Because the gelsolin domain binds to actin that mediates the protein localization, these results suggest that different protein localizations may also contribute to the regulation of MKP1.

Abstract Number: P17-539
Session Type: Poster