Project description:Plant cells employ cell-surface receptors to detect pathogens and launch immunity.Here we show that flg22 can induce a receptor-like kinase CERK1 phosphorylation at juxtamembrane region (JM). However, Genome-wide transcriptional reprogramming and other flg22 responses implied that CERK1 does not directly mediate flg22 signaling. Surprisingly, CERK1 JM phosphorylation can promote chitin responses and fungal resistance for plants and genome-wide transcriptional reprogramming also suggested no sign of constitutive immunity caused by this.
Project description:To confirm the flg22-induced BSU1 phosphorylation site, we performed targeted quantification by PRM analysis with SILIA IP-MS sample. The isotopes switched in replicate experiments.
Project description:To investigate flg22-induced posttranslational modification of BSU1 family proteins, we performed metabolic Stable Isotope Labeling In Arabidopsis followed by Immuno-Precipitation and Mass Spectrometry (SILIA IP-MS) analysis, with the isotopes switched in replicate experiments.
Project description:To study the effect of microbe-associated molecular pattern (MAMP) treatment (flg22) on the phosphorylation of nuclear proteins, we treated Arabidopsis plants with flg22 and after isolation of nuclear proteins, we enriched for phosphopeptides and then carried out LC-MS/MS analyses. We used statistical analysis tools to identify differentially phosphorylated proteins in response to MAMP treatment in the mock and treated samples.
Project description:The Microbe Associated Molecular Pattern flg22 is recognized in a FLAGELLIN-SENSITVE 2-dependent manner in root tip cells. Here, we show a rapid and massive change in protein abundance and phosphorylation state of the Arabidopsis root cell proteome in wildtype and a mutant deficient in heterotrimeric G-protein-coupled signaling. flg22-induced changes fall on proteins comprising a subset of this proteome, the heterotrimeric G protein interactome, and on highly populated hubs of the immunity network. Approximately 95% of the phosphorylation changes in the heterotrimeric G-protein interactome depend, at least partially, on a functional G protein complex. One member of this interactome is ATBa, a substrate subunit of a protein phosphatase 2A complex and an interactor to REGULATOR OF G SIGNALING 1 protein (AtRGS1), a flg22-phosphorylated, 7-transmembrane spanning modulator of the nucleotide-binding state of the core G-protein complex. A null mutation of ATBa strongly increases basal endocytosis of AtRGS1. AtRGS1 steady-state protein level is lower in the atba mutant in a proteasome-dependent manner. We propose that phosphorylation-dependent endocytosis of AtRGS1 is part of the mechanism to degrade AtRGS1 thus sustaining activation of the heterotrimeric G protein complex required for regulation of system dynamics in innate immunity. The PP2A(ATBa) complex is a critical regulator of this signaling pathway
