Arabidopsis AGO1 N-terminal extension acts as an essential hub for PRMT5 interaction and post-translational modifications

ABSTRACT: Plant ARGONAUTE (AGO) proteins play pivotal roles in gene expression regulation through small (s)RNA-guided mechanisms. Among the ten AGO proteins in Arabidopsis thaliana, AGO1 stands out as the main effector of post-transcriptional gene silencing. Intriguingly, a specific region of AGO1, its N-terminal extension (NTE), has gained prominence in recent studies linked to diverse regulatory functions, including subcellular localization, sRNA loading, and interactions with regulatory factors. In the realm of post-translational modifications (PTMs), little is known about arginine methylation in Arabidopsis AGOs. This study reveals a novel and intricate landscape of AGO1 methylation. Here, we have elucidated that NTEAGO1 undergoes symmetric arginine dimethylation on specific residues, and interacts with the methyltransferase PRMT5, which catalyzes its methylation. Notably, we observed that the lack of symmetric dimethylarginine has no discernible impact on AGO1's subcellular localization or miRNA loading capabilities. However, the absence of PRMT5 significantly alters the loading of a subgroup of sRNAs into AGO1 and reshapes the NTEAGO1 interactome. Importantly, our research extends beyond AGO1, illustrating that symmetric arginine dimethylation of NTEs is a common process across Arabidopsis AGOs, taking place in AGO1, AGO2, AGO3, and AGO5, deepening our understanding of PTMs in the intricate landscape of RNA-associated gene regulation.

INSTRUMENT(S): Orbitrap Fusion

ORGANISM(S): Arabidopsis Thaliana (mouse-ear Cress)

TISSUE(S): Leaf

SUBMITTER: Germán Rosano  

LAB HEAD: Nicolás Bologna

PROVIDER: PXD049971 | Pride | 2024-05-22

REPOSITORIES: Pride