[Wolfgang Schmidt] Protein Phosphorylation Orchestrates Acclimations to Ambient pH

Environment pH (pH_e) is a key parameter dictating a surfeit of conditions critical to plant survival and fitness. To elucidate the mechanisms that recalibrate cytoplasmic and apoplastic pH homeostasis, Dharmesh Jain and Wolfgang Schmidt conducted a comprehensive proteomic/phosphoproteomic inventory of plants subjected to transient exposure to acidic or alkaline pH, an approach that covered the majority of protein-coding genes of the reference plant Arabidopsis thaliana. The survey, recently published in Molecular & Cellular Proteomics, revealed a large set so far undocumented pH_e-dependent phospho-sites, indicative of extensive post-translational regulation of proteins involved in the acclimation to pH_e. Unexpectedly, the effect of pH_e was not restricted to roots and provoked pronounced changes in the leaf proteome. In both roots and shoots, the plant-specific TPLATE complex components AtEH1 and AtEH2–essential for clathrin-mediated endocytosis–were differentially phosphorylated at multiple sites in response to pH_e, possibly regulating the (pH_e-dependent) turnover of cargo proteins involved in signaling or regulating pH_cyt and pH_apo.

Link: https://www.mcponline.org/article/S1535-9476(23)00196-2/fulltext