Differentiation of 3T3-L1 fibroblasts to adipocytes induced by transfection of ras oncogenes.
Mammalian 3T3-L1 cells differentiate into adipocytes after continuous exposure to pharmacological doses of insulin or physiological doses of insulin-like growth factor I (IGF-1). Expression of transfected ras oncogenes led to differentiation of these cells into adipocytes in the absence of externally added insulin or IGF-I. Cells transfected with normal ras genes or the tyrosine kinase trk oncogene did not differentiate. Transfection with a dominant inhibitory ras mutant resulted in inhibition of differentiation. Exposure of untransfected 3T3-L1 cells to insulin stimulated formation of the active Ras.GTP complex. These observations indicate that Ras proteins participate in signal transduction pathways initiated by insulin and IGF-I in these cells.
Benito
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M
Laboratory of Molecular Microbiology, National Institute of Allergy and Infectious Diseases, National Institute of Health, Bethesda, MD 20892.
Porras
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Nebreda
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AR
Santos
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D000273:Adipose Tissue / Q000166:cytology*; D000818:Animals; D015152:Blotting, Northern; D002454:Cell Differentiation; D002460:Cell Line; D002471:Cell Transformation, Neoplastic; D005347:Fibroblasts / Q000166:cytology; D011905:Genes, ras; D051379:Mice; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics; D014162:Transfection
D012333:RNA, Messenger