Dynamic acetylation of WRKY63 is antagonistically regulated by HAG1 and HDA6 in Arabidopsis thaliana

Lysine acetylation is a crucial post-translational modification that regulates protein function, stability, and subcellular localization. While extensively studied in mammalian systems, its role in plants remains largely unexplored. In this study, we identify the histone acetyltransferase HAG1 and the histone deacetylase HDA6 as key antagonistic regulators of the transcription factor WRKY63 acetylation. Using bimolecular fluorescence complementation assays, split-luciferase assays, and co-immunoprecipitation assays, we demonstrate that WRKY63 interacts with HAG1 and HDA6. Furthermore, the N-terminal region of WRKY63 is essential for these interactions. HAG1-mediated acetylation enhances WRKY63 nuclear localization, whereas HDA6-mediated deacetylation reduces its nuclear retention. Moreover, transient transcriptional assays indicate that HDA6 represses WRKY63-mediated transcriptional activation. Our findings highlight the broader significance of lysine acetylation beyond histone modification, uncovering an antagonistic regulatory network that fine-tunes transcription factor activity in plants.