LC-MS/MS-based profiling of REIIBP-mediated methylation substrates within the nucleolus

Since REIIBP contains a complete SET domain and is associated with pre-rRNA processing factors in the nucleolus, we ask if REIIBP may methylate pre-rRNA processing factors in the nucleolus.To investigate this, we conducted LC-MS/MS analysis to identify potential protein substrates for methylation.