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Negative growth control by a novel low M r phosphotyrosine protein phosphatase in normal and transformed cells
Author(s) -
Ruggiero Marco,
Pazzagli Claudia,
Rigacci Stefania,
Magnelli Lucia,
Raugei Giovanni,
Berti Andrea,
Chiarugi Vincenzo P.,
Pierce Jacalyn H.,
Camici Guido,
Ramponi Giampietro
Publication year - 1993
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(93)81811-d
Subject(s) - phosphatase , cell growth , 3t3 cells , transfection , biology , growth factor , microbiology and biotechnology , enzyme , biochemistry , gene , receptor
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‐ erb B, 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.