Protein arginine methyltransferase 3 fine-tunes the assembly/disassembly of pre-ribosomes to repress nucleolar stress by interacting with RPS2B in arabidopsis

Ribosome biogenesis, which takes place mainly in the nucleolus, involves coordinated expression of pre-ribosomal RNAs (pre-rRNAs) and ribosomal proteins, pre-rRNA processing, subunit assembly with aid numerous factors. Our previous study showed that Arabidopsis thaliana protein arginine methyltransferase AtPRMT3 regulates processing; however, underlying molecular mechanism remains unknown. Here, we report interacts Ribosomal Protein S2 (RPS2), facilitating processing 90S/Small Subunit (SSU) processome repressing nucleolar stress. We isolated an intragenic suppressor atprmt3-2, rescues developmental defects atprmt3-2 while produces a putative truncated bearing entire N-terminus but lacking intact enzymatic activity domain further identified RPS2 as interacting partner AtPRMT3, found loss-of-function rps2a2b mutants were phenotypically reminiscent atprmt3, showing pleiotropic aberrant processing. RPS2B binds directly to pre-rRNAs nucleus, such binding is enhanced atprmt3-2. Consistently, multiple components 90S/SSU more enriched by accounts for early results Collectively, our uncovered novel cooperates facilitate dynamic assembly/disassembly during ribosome biogenesis repress