title: Profiling impaired hepatic endoplasmic reticulum glycosylation as a consequence of ethanol ingestion.
abstract: Alcoholic liver disease (ALD) is a prominent cause of morbidity and mortality in the United States. Alterations in protein folding occur in numerous disease states, including ALD. The endoplasmic reticulum (ER) is the primary site of post-translational modifications (PTM) within the cell. Glycosylation, the most abundant PTM, affects protein stability, structure, localization, and activity. Decreases in hepatic glycosylation machinery have been observed in rodent models of ALD, but specific protein targets have not been identified. Utilizing two-dimensional gel electrophoresis and liquid chromatography-tandem mass spectrometry, glycoproteins were identified in hepatic microsomal fractions from control and ethanol-fed mice. This study reports for the first time a global decrease in ER glycosylation. Additionally, the identification of 30 glycoproteins within this fraction elucidates pathway-specific alterations in ALD impaired glycosylation. Among the identified proteins, triacylglycerol hydrolase (TGH) is positively affected by glycosylation, showing increased activity following the addition of sugar moieties. Impaired TGH activity is associated with increased cellular storage of lipids and provides a potential mechanism for the observed pathologies associated with ALD.
authors.affiliation: Department of Pharmacology, University of Colorado Denver, Aurora, Colorado 80045, United States.
authors.forename: James J
authors.initials: JJ
authors.lastname: Galligan
authors.forename: Kristofer S
authors.initials: KS
authors.lastname: Fritz
authors.forename: Hannah
authors.initials: H
authors.lastname: Tipney
authors.forename: Rebecca L
authors.initials: RL
authors.lastname: Smathers
authors.forename: James R
authors.initials: JR
authors.lastname: Roede
authors.forename: Colin T
authors.initials: CT
authors.lastname: Shearn
authors.forename: Lawrence E
authors.initials: LE
authors.lastname: Hunter
authors.forename: Dennis R
authors.initials: DR
authors.lastname: Petersen
mesh_terms: D000818:Animals; D002853:Chromatography, Liquid / Q000379:methods; D015180:Electrophoresis, Gel, Two-Dimensional / Q000379:methods; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D000431:Ethanol / Q000008:administration & dosage / Q000378:metabolism*; D006023:Glycoproteins / Q000032:analysis* / Q000235:genetics; D006031:Glycosylation; D006801:Humans; D008099:Liver / Q000737:chemistry* / Q000166:cytology* / Q000473:pathology; D008108:Liver Diseases, Alcoholic / Q000378:metabolism / Q000473:pathology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008862:Microsomes, Liver / Q000737:chemistry; D018384:Oxidative Stress; D040901:Proteomics / Q000379:methods; D053719:Tandem Mass Spectrometry / Q000379:methods
chemical_list: D006023:Glycoproteins; D000431:Ethanol