title: Protein phosphorylation on tyrosine restores expression and glycosylation of cyclooxygenase-2 by 2-deoxy-D-glucose-caused endoplasmic reticulum stress in rabbit articular chondrocyte.
abstract: 2-deoxy-D-glucose(2DG)-caused endoplasmic reticulum (ER) stress inhibits protein phosphorylation at tyrosine residues. However, the accurate regulatory mechanisms, which determine the inflammatory response of chondrocytes to ER stress via protein tyrosine phosphorylation, have not been systematically evaluated. Thus, in this study, we examined whether protein phosphorylation at tyrosine residues can modulate the expression and glycosylation of COX-2, which is reduced by 2DG-induced ER stress. We observed that protein tyrosine phosphatase (PTP) inhibitors, sodium orthovanadate (SOV), and phenylarsine oxide (PAO) significantly decreased expression of ER stress inducible proteins, glucose-regulated protein 94 (GRP94), and CCAAT/enhancer-binding-protein- related gene (GADD153), which was induced by 2DG. In addition, we demonstrated that SOV and PAO noticeably restored the expression and glycosylation of COX-2 after treatment with 2DG. These results suggest that protein phosphorylation of tyrosine residues plays an important role in the regulation of expression and glycosylation during 2DG-induced ER stress in rabbit articular chondrocytes.
authors.affiliation: Department of Biological Sciences, College of Natural Sciences, Kongju National University, Gongju 314-701, Korea.
authors.forename: Seon-Mi
authors.initials: SM
authors.lastname: Yu
authors.forename: Song-Ja
authors.initials: SJ
authors.lastname: Kim
mesh_terms: D000818:Animals; D002358:Cartilage, Articular / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D019902:Chondrocytes / Q000187:drug effects* / Q000378:metabolism; D051546:Cyclooxygenase 2 / Q000235:genetics* / Q000378:metabolism*; D003847:Deoxyglucose / Q000009:adverse effects* / Q000494:pharmacology; D059865:Endoplasmic Reticulum Stress / Q000187:drug effects* / Q000235:genetics / Q000502:physiology; D015971:Gene Expression Regulation, Enzymologic; D006031:Glycosylation; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism; D010766:Phosphorylation / Q000502:physiology; D011499:Protein Processing, Post-Translational / Q000502:physiology*; D011505:Protein-Tyrosine Kinases / Q000378:metabolism / Q000502:physiology; D011817:Rabbits; D051742:Transcription Factor CHOP / Q000378:metabolism; D014443:Tyrosine / Q000378:metabolism
chemical_list: D018840:HSP70 Heat-Shock Proteins; D008565:Membrane Proteins; C018551:glucose-regulated proteins; D051742:Transcription Factor CHOP; D014443:Tyrosine; D003847:Deoxyglucose; D051546:Cyclooxygenase 2; D011505:Protein-Tyrosine Kinases