title: Structural Analysis of Free N-Glycans in α-Glucosidase Mutants of Saccharomyces cerevisiae: Lack of the Evidence for the Occurrence of Catabolic α-Glucosidase Acting on the N-Glycans.
abstract: Saccharomyces cerevisiae produces two different α-glucosidases, Glucosidase 1 (Gls1) and Glucosidase 2 (Gls2), which are responsible for the removal of the glucose molecules from N-glycans (Glc3Man9GlcNAc2) of glycoproteins in the endoplasmic reticulum. Whether any additional α-glucosidases playing a role in catabolizing the glucosylated N-glycans are produced by this yeast, however, remains unknown. We report herein on a search for additional α-glucosidases in S. cerevisiae. To this end, the precise structures of cytosolic free N-glycans (FNGs), mainly derived from the peptide:N-glycanase (Png1) mediated deglycosylation of N-glycoproteins were analyzed in the endoplasmic reticulum α-glucosidase-deficient mutants. 12 new glucosylated FNG structures were successfully identified through 2-dimentional HPLC analysis. On the other hand, non-glucosylated FNGs were not detected at all under any culture conditions. It can therefore be safely concluded that no catabolic α-glucosidases acting on N-glycans are produced by this yeast.
authors.affiliation: Glycometabolome Team, Systems Glycobiology Research Group, RIKEN-Max Planck Joint Research Center for Systems Chemical Biology, RIKEN Global Research Cluster, Wako, Saitama, Japan.|Graduate School of Science and Engineering, Saitama University, Sakura, Saitama, Japan.
authors.forename: Tanim Jabid
authors.initials: TJ
authors.lastname: Hossain
authors.affiliation: Glycometabolome Team, Systems Glycobiology Research Group, RIKEN-Max Planck Joint Research Center for Systems Chemical Biology, RIKEN Global Research Cluster, Wako, Saitama, Japan.
authors.forename: Yoichiro
authors.initials: Y
authors.lastname: Harada
authors.affiliation: Glycometabolome Team, Systems Glycobiology Research Group, RIKEN-Max Planck Joint Research Center for Systems Chemical Biology, RIKEN Global Research Cluster, Wako, Saitama, Japan.
authors.forename: Hiroto
authors.initials: H
authors.lastname: Hirayama
authors.affiliation: Glycometabolome Team, Systems Glycobiology Research Group, RIKEN-Max Planck Joint Research Center for Systems Chemical Biology, RIKEN Global Research Cluster, Wako, Saitama, Japan.|Graduate School of Science and Engineering, Saitama University, Sakura, Saitama, Japan.
authors.forename: Haruna
authors.initials: H
authors.lastname: Tomotake
authors.affiliation: Japan Science and Technology Agency (JST), ERATO Ito Glycotrilogy Project, Wako, Saitama, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Seko
authors.affiliation: Glycometabolome Team, Systems Glycobiology Research Group, RIKEN-Max Planck Joint Research Center for Systems Chemical Biology, RIKEN Global Research Cluster, Wako, Saitama, Japan.|Graduate School of Science and Engineering, Saitama University, Sakura, Saitama, Japan.
authors.forename: Tadashi
authors.initials: T
authors.lastname: Suzuki
mesh_terms: D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D008969:Molecular Sequence Data; D009154:Mutation; D011134:Polysaccharides / Q000737:chemistry / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D000520:alpha-Glucosidases / Q000235:genetics / Q000378:metabolism*
chemical_list: D011134:Polysaccharides; D029701:Saccharomyces cerevisiae Proteins; D000520:alpha-Glucosidases