Chromatin phosphoproteomics unravels a function for AT-hook motif nuclear localized protein AHL13 in PAMP-triggered immunity
Naganand Rayapuram, Mai Jarad, Hanna Alhoraibi, Jean Bigeard, Aala A. Abulfaraj, Ronny Völz, Kiruthiga Mariappan, Marília Almeida-Trapp, Maria A. Schlöffel, Emmanuelle Lastrucci, Ludovic Bonhomme, Andrea A. Gust, Axel Mithöfer, Stefan T. Arold, Delphine Pflieger, Heribert Hirt
Abstract
Significance Mitogen-activated protein kinases (MAPKs) function in all eukaryotes in signaling extracellular stimuli to intracellular responses and ultimately link them to chromatin events by targeting transcription factors and chromatin remodeling complexes. In plants, MAPKs play crucial roles in immunity, development, and stress responses, but so far no attempts have been made to identify phosphorylation of chromatin-associated proteins. By using a phosphoproteomic approach on MAPK mutants, we identified a number of chromatin-associated MAPK substrates and characterize an AT-hook motif containing nuclear localized (AHL) DNA-binding protein 13 in plant immunity and demonstrate that phosphorylation regulates AHL13 protein stability and, in turn, its function in response to pathogens.