title: Phosphotyrosyl protein phosphatase-like activity of a clonal osteoblastic cell line (MC3T3-E1 cell).
abstract: The homogenate of MC3T3-E1 cells hydrolysed phosphotyrosine, but not phosphoserine or phosphothreonine at acidic pH. It dephosphorylated lysozyme and Raytide (a gastrin analogue peptide) phosphorylated by tyrosine kinase, but showed little activity toward histones phosphorylated by cyclic AMP-dependent protein kinase. Dephosphorylation of phosphorylated lysozyme and Raytide were inhibited by zinc and vanadate, but were insensitive to okadaic acid. These data suggest that the osteoblastic cell line MC3T3-E1 has a phosphotyrosyl protein phosphatase-like activity that may participate in cellular regulation involving protein tyrosine phosphorylation.
authors.affiliation: Department of Dental Pharmacology, School of Dentistry, Hokkaido University, Sapporo, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Suzuki
authors.forename: T
authors.initials: T
authors.lastname: Okamoto
authors.forename: Y
authors.initials: Y
authors.lastname: Yoshimura
authors.forename: Y
authors.initials: Y
authors.lastname: Deyama
authors.forename: Y
authors.initials: Y
authors.lastname: Hisada
authors.forename: A
authors.initials: A
authors.lastname: Matsumoto
mesh_terms: D016475:3T3 Cells; D000818:Animals; D002460:Cell Line; D002999:Clone Cells; D000242:Cyclic AMP / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004988:Ethers, Cyclic / Q000494:pharmacology; D006657:Histones / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D051379:Mice; D009113:Muramidase / Q000037:antagonists & inhibitors / Q000378:metabolism; D019319:Okadaic Acid; D010006:Osteoblasts / Q000201:enzymology*; D010455:Peptides / Q000037:antagonists & inhibitors / Q000378:metabolism; D010749:Phosphoprotein Phosphatases / Q000037:antagonists & inhibitors; D010766:Phosphorylation / Q000187:drug effects; D010768:Phosphoserine / Q000378:metabolism; D010769:Phosphothreonine / Q000378:metabolism; D019000:Phosphotyrosine / Q000378:metabolism; D011494:Protein Kinases / Q000378:metabolism; D017027:Protein Tyrosine Phosphatases / Q000378:metabolism*; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D014638:Vanadates / Q000494:pharmacology; D015032:Zinc / Q000494:pharmacology
chemical_list: D004791:Enzyme Inhibitors; D004988:Ethers, Cyclic; D006657:Histones; D010455:Peptides; D010769:Phosphothreonine; C071998:Raytide; D010768:Phosphoserine; D019319:Okadaic Acid; D019000:Phosphotyrosine; D014638:Vanadates; D000242:Cyclic AMP; D011494:Protein Kinases; D011505:Protein-Tyrosine Kinases; D010749:Phosphoprotein Phosphatases; D017027:Protein Tyrosine Phosphatases; D009113:Muramidase; D015032:Zinc