Identification and Localization of Phosphoproteins in v-onc Transformed Fibroblasts by Means of Phosphotyrosine Antibodies

摘要: The transformation process induced by several retroviruses, includ­ing Rous sarcoma virus (RSV), Feline (FeSV), Fujinami avian (FSV) and Abelson murine leukemia (AMuLV), is triggered maintained the action of v-onc genes which all code for transforming proteins with associated tyrosine kinase activity (for review see 1). Since protein phosphorylation seems to be invariably molecular mechanism(s) involved in growth control neoplastic these identification cellular phosphorylated at residues an issue major importance. Putative substrates kinases have been identified means conventional techniques such as bidimensional separation total followed phosphoaminoacid analysis. However, seem intrinsic limitations - shown also failure identify well known themselves, are heavily tyrosine-phosphorylated. difficulties generated fact that phosphotyrosine represents less than 2% phospho­aminoacids transformed cells (being 0.2% nor­mal cells); addition it has that, only a minor frac­tion, i.e. 10%, each substrate molecules coded kinases, even fully trans­formed cells.