title: Effects of H2O2 on protein tyrosine phosphatase activity in HER14 cells.
abstract: Oxidative stress has been implicated in protein phosphorylation and dephosphorylation in cells. In our current studies, H2O2 was shown to reversibly inhibit protein tyrosine phosphatase (PTPase) activity in HER14 cells. H2O2 (150 mM) resulted in 40% inhibition of PTPase activity by 15 min and recovery from inhibition was nearly complete by 60 min. H2O2-induced inhibition or recovery of PTPase activity was not affected by cycloheximide, a protein synthesis inhibitor. L-Buthionine-[S,R]-sulfoximine (BSO), an inhibitor of glutathione synthesis, had no effect on H2O2-induced inhibition of PTPase activity but retarded the recovery of activity. Epidermal growth factor (EGF) and EGTA, a Ca2+ chelator, did not influence H2O2-induced inhibition or recovery of PTPase activity. These results suggest that at least 40% of fibroblast PTPase activity can be regulated by cellular redox activity.
authors.affiliation: Department of Pharmacology, New York University School of Medicine, NY 10016.
authors.forename: S G
authors.initials: SG
authors.lastname: Sullivan
authors.forename: D T
authors.initials: DT
authors.lastname: Chiu
authors.forename: M
authors.initials: M
authors.lastname: Errasfa
authors.forename: J M
authors.initials: JM
authors.lastname: Wang
authors.forename: J S
authors.initials: JS
authors.lastname: Qi
authors.forename: A
authors.initials: A
authors.lastname: Stern
mesh_terms: D016475:3T3 Cells / Q000187:drug effects / Q000378:metabolism; D000818:Animals; D002460:Cell Line; D003513:Cycloheximide / Q000494:pharmacology; D004815:Epidermal Growth Factor / Q000494:pharmacology; D066246:ErbB Receptors / Q000378:metabolism; D005609:Free Radicals; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D051379:Mice; D010084:Oxidation-Reduction; D017027:Protein Tyrosine Phosphatases / Q000037:antagonists & inhibitors*
chemical_list: D005609:Free Radicals; D004815:Epidermal Growth Factor; D003513:Cycloheximide; D006861:Hydrogen Peroxide; D066246:ErbB Receptors; D017027:Protein Tyrosine Phosphatases