title: Yeast protein glycation in vivo by methylglyoxal. Molecular modification of glycolytic enzymes and heat shock proteins.
abstract: Protein glycation by methylglyoxal is a nonenzymatic post-translational modification whereby arginine and lysine side chains form a chemically heterogeneous group of advanced glycation end-products. Methylglyoxal-derived advanced glycation end-products are involved in pathologies such as diabetes and neurodegenerative diseases of the amyloid type. As methylglyoxal is produced nonenzymatically from dihydroxyacetone phosphate and d-glyceraldehyde 3-phosphate during glycolysis, its formation occurs in all living cells. Understanding methylglyoxal glycation in model systems will provide important clues regarding glycation prevention in higher organisms in the context of widespread human diseases. Using Saccharomyces cerevisiae cells with different glycation phenotypes and MALDI-TOF peptide mass fingerprints, we identified enolase 2 as the primary methylglyoxal glycation target in yeast. Two other glycolytic enzymes are also glycated, aldolase and phosphoglycerate mutase. Despite enolase's activity loss, in a glycation-dependent way, glycolytic flux and glycerol production remained unchanged. None of these enzymes has any effect on glycolytic flux, as evaluated by sensitivity analysis, showing that yeast glycolysis is a very robust metabolic pathway. Three heat shock proteins are also glycated, Hsp71/72 and Hsp26. For all glycated proteins, the nature and molecular location of some advanced glycation end-products were determined by MALDI-TOF. Yeast cells experienced selective pressure towards efficient use of d-glucose, with high methylglyoxal formation as a side effect. Glycation is a fact of life for these cells, and some glycolytic enzymes could be deployed to contain methylglyoxal that evades its enzymatic catabolism. Heat shock proteins may be involved in proteolytic processing (Hsp71/72) or protein salvaging (Hsp26).
authors.affiliation: Centro de Química e Bioquímica, Departamento de Química e Bioquímica, Faculdade de Ciências da Universidade de Lisboa, Portugal.
authors.forename: Ricardo A
authors.initials: RA
authors.lastname: Gomes
authors.forename: Hugo
authors.initials: H
authors.lastname: Vicente Miranda
authors.forename: Marta Sousa
authors.initials: MS
authors.lastname: Silva
authors.forename: Gonçalo
authors.initials: G
authors.lastname: Graça
authors.forename: Ana V
authors.initials: AV
authors.lastname: Coelho
authors.forename: António E
authors.initials: AE
authors.lastname: Ferreira
authors.forename: Carlos
authors.initials: C
authors.lastname: Cordeiro
authors.forename: Ana Ponces
authors.initials: AP
authors.lastname: Freire
mesh_terms: D000595:Amino Acid Sequence; D003198:Computer Simulation; D005634:Fructose-Bisphosphate Aldolase / Q000378:metabolism; D006019:Glycolysis; D006031:Glycosylation; D050884:HSP72 Heat-Shock Proteins / Q000737:chemistry / Q000378:metabolism; D006360:Heat-Shock Proteins / Q000737:chemistry / Q000378:metabolism*; D018832:Molecular Chaperones / Q000378:metabolism; D008969:Molecular Sequence Data; D010736:Phosphoglycerate Mutase / Q000378:metabolism; D010751:Phosphopyruvate Hydratase / Q000737:chemistry / Q000378:metabolism; D011487:Protein Conformation; D017510:Protein Folding; D011765:Pyruvaldehyde / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000378:metabolism*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013997:Time Factors
chemical_list: C499528:HSP26 protein, S cerevisiae; D050884:HSP72 Heat-Shock Proteins; D006360:Heat-Shock Proteins; D018832:Molecular Chaperones; D029701:Saccharomyces cerevisiae Proteins; D011765:Pyruvaldehyde; D005634:Fructose-Bisphosphate Aldolase; D010751:Phosphopyruvate Hydratase; C516797:enolase 2, S cerevisiae; D010736:Phosphoglycerate Mutase