title: Methylation of translation-associated proteins in Saccharomyces cerevisiae: Identification of methylated lysines and their methyltransferases.
abstract: This study aimed to identify sites of lysine methylation in Saccharomyces cerevisiae and the associated methyltransferases. Hexapeptide ligand affinity chromatography was used to normalize the abundance levels of proteins in whole cell lysate. MS/MS, in association with antibody-based detection, was then used to identify lysine methylated proteins and the precise sites of modification. Lysine methylation was found on the proteins elongation factor (EF) 1-α, 2, and 3A, as well as ribosomal proteins 40S S18-A/B, 60S L11-A/B, L18-A/B, and L42-A/B. Precise sites were mapped in all cases. Single-gene knockouts of known and putative methyltransferase(s), in association with MS/MS, showed that EF1-α is monomethylated by Efm1 at lysin 30 and dimethylated by See1 at lysine 316. Methyltransferase Rkm1 was found to monomethylate 40S ribosomal protein S18-A/B at lysine 48. Knockout analysis also revealed that putative methyltransferase YBR271W affects the methylation of proteins EF2 and 3A; this was detected by Western blotting and immunodetection. This methyltransferase shows strong interspecies conservation and a tryptophan-containing motif associated with its active site. We suggest that enzyme YBR271W is named EF methyltransferase 2 (Efm2), in line with the recent naming of YHL039W as Efm1.
authors.affiliation: Systems Biology Initiative, School of Biotechnology and Biomolecular Sciences, University of New South Wales, NSW, Australia.
authors.forename: Timothy A
authors.initials: TA
authors.lastname: Couttas
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Raftery
authors.forename: Matthew P
authors.initials: MP
authors.lastname: Padula
authors.forename: Ben R
authors.initials: BR
authors.lastname: Herbert
authors.forename: Marc R
authors.initials: MR
authors.lastname: Wilkins
mesh_terms: D000595:Amino Acid Sequence; D002846:Chromatography, Affinity; D006801:Humans; D008239:Lysine / Q000737:chemistry / Q000378:metabolism; D008745:Methylation; D008780:Methyltransferases / Q000737:chemistry* / Q000378:metabolism; D008969:Molecular Sequence Data; D010445:Peptide Elongation Factors / Q000737:chemistry* / Q000378:metabolism; D020543:Proteome / Q000737:chemistry* / Q000378:metabolism; D040901:Proteomics / Q000379:methods; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry* / Q000378:metabolism; D016415:Sequence Alignment; D053719:Tandem Mass Spectrometry
chemical_list: D010445:Peptide Elongation Factors; D020543:Proteome; D029701:Saccharomyces cerevisiae Proteins; D008780:Methyltransferases; D008239:Lysine