title: Proteomic analysis of interactors for yeast protein arginine methyltransferase Hmt1 reveals novel substrate and insights into additional biological roles.
abstract: Protein arginine methylation is a PTM catalyzed by an evolutionarily conserved family of enzymes called protein arginine methyltransferases (PRMTs), with PRMT1 being the most conserved member of this enzyme family. This modification has emerged to be an important regulator of protein functions. To better understand the role of PRMTs in cellular pathways and functions, we have carried out a proteomic profiling experiment to comprehensively identify the physical interactors of Hmt1, the budding yeast homolog for human PRMT1. Using a dual-enzymatic digestion linear trap quadrupole/Orbitrap proteomic strategy, we identified a total of 108 proteins that specifically copurify with Hmt1 by tandem affinity purification. A reverse coimmunoprecipitation experiment was used to confirm Hmt1's physical association with Bre5, Mtr4, Snf2, Sum1, and Ssd1, five proteins that were identified as Hmt1-specific interactors in multiple biological replicates. To determine whether the identified Hmt1-interactors had the potential to act as an Hmt1 substrate, we used published bioinformatics algorithms that predict the presence and location of potential methylarginines for each identified interactor. One of the top hits from this analysis, Snf2, was experimentally confirmed as a robust substrate of Hmt1 in vitro. Overall, our data provide a feasible proteomic approach that aid in the better understanding of PRMT1's roles within a cell.
authors.affiliation: Department of Biological Sciences, State University of New York at Buffalo, Buffalo, New York 14260, USA.
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Jackson
authors.forename: Neelu
authors.initials: N
authors.lastname: Yadav
authors.forename: Sangwon
authors.initials: S
authors.lastname: Min
authors.forename: Jun
authors.initials: J
authors.lastname: Li
authors.forename: Eric J
authors.initials: EJ
authors.lastname: Milliman
authors.forename: Jun
authors.initials: J
authors.lastname: Qu
authors.forename: Yin-Chu
authors.initials: YC
authors.lastname: Chen
authors.forename: Michael C
authors.initials: MC
authors.lastname: Yu
mesh_terms: D000251:Adenosine Triphosphatases / Q000737:chemistry / Q000378:metabolism; D000595:Amino Acid Sequence; D001120:Arginine / Q000737:chemistry / Q000378:metabolism; D003198:Computer Simulation; D008745:Methylation; D008969:Molecular Sequence Data; D025941:Protein Interaction Mapping / Q000379:methods*; D011484:Protein-Arginine N-Methyltransferases / Q000737:chemistry / Q000378:metabolism*; D020543:Proteome / Q000032:analysis / Q000737:chemistry / Q000378:metabolism*; D040901:Proteomics / Q000379:methods*; D012097:Repressor Proteins / Q000737:chemistry / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000378:metabolism*; D016415:Sequence Alignment; D014157:Transcription Factors / Q000737:chemistry / Q000378:metabolism
chemical_list: D020543:Proteome; D012097:Repressor Proteins; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D001120:Arginine; C475182:HMT1 protein, S cerevisiae; D011484:Protein-Arginine N-Methyltransferases; D000251:Adenosine Triphosphatases; C499333:SNF2 protein, S cerevisiae