title: A congenital disorder of deglycosylation: Biochemical characterization of N-glycanase 1 deficiency in patient fibroblasts.
abstract: N-Glycanase 1, encoded by NGLY1, catalyzes the deglycosylation of misfolded N-linked glycoproteins retrotranslocated into the cytosol. We identified nine cases with mutations in NGLY1. The patients show developmental delay, seizures, peripheral neuropathy, abnormal liver function and alacrima (absence of tears). The mutations in NGLY1 resulted in the absence of N-glycanase 1 protein in patient-derived fibroblasts. Applying a recently established cellular deglycosylation-dependent Venus fluorescence assay, we found that patient fibroblasts had dramatically reduced fluorescence, indicating a pronounced reduction in N-glycanase enzymatic activity. Using this assay, we could find no evidence of other related activities. Our findings reveal that NGLY1 mutations destroy both N-glycanase 1 protein and enzymatic activity.
authors.affiliation: Human Genetics Program, Sanford Children's Health Research Center, Sanford Burnham Medical Research Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA.
authors.forename: Ping
authors.initials: P
authors.lastname: He
authors.affiliation: Department of Immunobiology, Yale University, School of Medicine, New Haven, CT 06520-8011, USA.
authors.forename: Jeff E
authors.initials: JE
authors.lastname: Grotzke
authors.affiliation: Human Genetics Program, Sanford Children's Health Research Center, Sanford Burnham Medical Research Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA.
authors.forename: Bobby G
authors.initials: BG
authors.lastname: Ng
authors.affiliation: Yale Program on Neurogenetics, Departments of Neurosurgery, Neurobiology and Genetics, Yale University, School of Medicine, New Haven, CT 06510, USA.
authors.forename: Murat
authors.initials: M
authors.lastname: Gunel
authors.affiliation: Department of Molecular and Human Genetics, Program in Developmental Biology, Baylor College of Medicine, Houston, TX 77030, USA.
authors.forename: Hamed
authors.initials: H
authors.lastname: Jafar-Nejad
authors.affiliation: Department of Immunobiology, Yale University, School of Medicine, New Haven, CT 06520-8011, USA.
authors.forename: Peter
authors.initials: P
authors.lastname: Cresswell
authors.affiliation: Department of Pediatrics, Division of Medical Genetics, Lucile Packard Children's Hospital, Stanford University, Stanford, CA 94304, USA.
authors.forename: Gregory M
authors.initials: GM
authors.lastname: Enns
authors.affiliation: Human Genetics Program, Sanford Children's Health Research Center, Sanford Burnham Medical Research Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA hudson@sanfordburnham.org.
authors.forename: Hudson H
authors.initials: HH
authors.lastname: Freeze
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D002658:Developmental Disabilities / Q000235:genetics* / Q000473:pathology; D057075:Enzyme Assays; D005091:Exons; D015785:Eye Diseases, Hereditary / Q000235:genetics*; D005347:Fibroblasts / Q000201:enzymology / Q000473:pathology; D015870:Gene Expression; D017930:Genes, Reporter; D048550:Hepatic Insufficiency / Q000151:congenital / Q000235:genetics*; D006801:Humans; D007766:Lacrimal Apparatus Diseases / Q000151:congenital / Q000235:genetics*; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D043524:Peptide-N4-(N-acetyl-beta-glucosaminyl) Asparagine Amidase / Q000172:deficiency / Q000235:genetics*; D010523:Peripheral Nervous System Diseases / Q000151:congenital / Q000235:genetics*; D061251:Primary Cell Culture; D012640:Seizures / Q000151:congenital / Q000235:genetics*
chemical_list: D001426:Bacterial Proteins; D008164:Luminescent Proteins; C054562:yellow fluorescent protein, Bacteria; D043524:Peptide-N4-(N-acetyl-beta-glucosaminyl) Asparagine Amidase
keywords: N-glycanase 1 deficiency; Z-VAD; deglycosylation-dependent venus (ddVenus) fluorescence assay