Evaluating Phosphorylation as a Potential Regulator of ADT5 in Arabidopsis thaliana
Abstract
In Arabidopsis thaliana, a family of six AROGENATE DEHYDRATASE (ADT) enzymes catalyze the final step of Phe biosynthesis. While all AtADTs localize to chloroplasts, my work focuses on AtADT5, which is the only isoform also found in nuclei. Based on in silico evidence, I hypothesized that phosphorylation regulates AtADT5’s subcellular localization and function. Using bimolecular fluorescence complementation, I found that AtADT5 is a phosphoprotein in vivo. Further, I designed an experimental approach that will allow profiling all post‑translational modifications in AtADT5 using mass spectrometry. Lastly, I tested the effect of phosphorylation on AtADT5’s subcellular localization using phosphomimetics and found no change relative to wildtype. This work is the first demonstration that AtADT5 is phosphorylated in vivo and contributes to our understanding of the regulation of the ADT gene family.