Acetylproteomics analyses reveal critical features of lysine-ε-acetylation in Arabidopsis and a role of 14-3-3 protein acetylation in alkaline response

Abstract Lysine-ε-acetylation (Kac) is a post-translational modification (PTM) that critical for metabolic regulation and cell signaling in mammals. However, its prevalence importance plants remain to be determined. Employing high-resolution tandem mass spectrometry, we analyzed protein lysine acetylation five representative Arabidopsis organs with 2 ~ 3 biological replicates per organ. A total of 2887 Kac proteins 5929 sites were identified. This comprehensive catalog allows us analyze proteome-wide features acetylation. We found tend more uniformly expressed different organs, the status exhibits little correlation gene expression level, indicating unlikely caused by stochastic processes. preferentially targets evolutionarily conserved residues, but only small percentage are orthologous between rat Arabidopsis. large portion overlap modified other PTMs including ubiquitination, SUMOylation phosphorylation. Although acetylation, ubiquitination all modify our analyses show they rarely target same sites. In addition, “reader” phosphorylation, i.e., bromodomain-containing GRF (General Regulatory Factor)/14-3-3 proteins, intensively two PTMs, suggesting main crosstalk nodes phosphorylation signaling. Analyses GRF6/14-3-3λ reveal level GRF6 decreased under alkaline stress, represses plant response. Indeed, K56ac inhibits binding subsequent activation plasma membrane H + -ATPase AHA2, leading hypersensitivity stress. These results provide valuable resources studies suppresses output acetylating GRF/14-3-3 proteins.