title: Negative growth control by a novel low M(r) phosphotyrosine protein phosphatase in normal and transformed cells.
abstract: Having determined the complete amino acid sequence of a cytosolic phosphatase purified from bovine liver, we studied the role of this enzyme (referred to as 'PTPase') in the control of cell proliferation. We used NIH/3T3 fibroblasts, both normal and transformed by the oncogenes v-erbB, v-src, and v-raf: a synthetic gene coding for PTPase was transfected into, and overexpressed in, normal and transformed NIH/3T3 cells with resulting inhibition of cell growth. Inhibition of proliferation correlated with the level of foreign PTPase; growth in soft agar was also inhibited in transformants overexpressing the enzyme. However, PTPase overexpression did not inhibit the rapid turnover of inositol lipids stimulated by platelet-derived growth factor. We conclude that this novel PTPase is active on cell type-specific signalling substrates that control normal and transformed fibroblast proliferation.
authors.affiliation: Institute of General Pathology, University of Firenze, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Ruggiero
authors.forename: C
authors.initials: C
authors.lastname: Pazzagli
authors.forename: S
authors.initials: S
authors.lastname: Rigacci
authors.forename: L
authors.initials: L
authors.lastname: Magnelli
authors.forename: G
authors.initials: G
authors.lastname: Raugei
authors.forename: A
authors.initials: A
authors.lastname: Berti
authors.forename: V P
authors.initials: VP
authors.lastname: Chiarugi
authors.forename: J H
authors.initials: JH
authors.lastname: Pierce
authors.forename: G
authors.initials: G
authors.lastname: Camici
authors.forename: G
authors.initials: G
authors.lastname: Ramponi
mesh_terms: D016475:3T3 Cells; D000818:Animals; D002455:Cell Division; D002461:Cell Line, Transformed; D015870:Gene Expression; D016391:Genes, src; D007295:Inositol Phosphates / Q000378:metabolism; D051379:Mice; D018739:Oncogene Proteins v-erbB; D027384:Oncogene Proteins v-raf; D010982:Platelet-Derived Growth Factor / Q000494:pharmacology; D017027:Protein Tyrosine Phosphatases / Q000235:genetics / Q000378:metabolism*; D015682:Retroviridae Proteins, Oncogenic / Q000235:genetics*; D014162:Transfection
chemical_list: D007295:Inositol Phosphates; D018739:Oncogene Proteins v-erbB; D010982:Platelet-Derived Growth Factor; D015682:Retroviridae Proteins, Oncogenic; D027384:Oncogene Proteins v-raf; D017027:Protein Tyrosine Phosphatases