title: The role of glucosidase II and endomannosidase in glucose trimming of asparagine-linked oligosaccharides.
abstract: This review covers various aspects of glucose trimming reactions occurring on asparagine-linked oligosaccharides. Structural and functional features of two enzymes, glucosidase II and endo-alpha-mannosidase, prominently involved in this process are summarized and their striking differences in terms of substrate specificities are highlighted. Recent results of analyses by immunoelectron microscopy of their distribution pattern are presented which demonstrate that glucose trimming is not restricted to the endoplasmic reticulum (ER) but additionally is a function accommodated by the Golgi apparatus. The mutually exclusive subcellular distribution of glucosidase II and endomannosidase are discussed in terms of their significance for quality control of protein folding and N-glycosylation.
authors.affiliation: Division of Cell and Molecular Pathology, Department of Pathology, University of Zurich, Switzerland. juergen.roth@usz.ch
authors.forename: Jürgen
authors.initials: J
authors.lastname: Roth
authors.forename: Martin
authors.initials: M
authors.lastname: Ziak
authors.forename: Christian
authors.initials: C
authors.lastname: Zuber
mesh_terms: D000818:Animals; D001216:Asparagine / Q000737:chemistry; D004721:Endoplasmic Reticulum / Q000378:metabolism; D005947:Glucose / Q000737:chemistry / Q000378:metabolism; D006031:Glycosylation; D006056:Golgi Apparatus / Q000378:metabolism; D066298:In Vitro Techniques; D008361:Mannosidases / Q000378:metabolism*; D009844:Oligosaccharides / Q000737:chemistry* / Q000378:metabolism*; D017510:Protein Folding; D020033:Protein Isoforms / Q000378:metabolism; D013379:Substrate Specificity; D000520:alpha-Glucosidases / Q000378:metabolism*
chemical_list: D009844:Oligosaccharides; D020033:Protein Isoforms; D001216:Asparagine; C034251:4-nitrophenyl-alpha-glucosidase; D008361:Mannosidases; D000520:alpha-Glucosidases; D005947:Glucose