Ras GTPase-activating protein-associated p62 is a major v-Src-SH3-binding protein.
Oncogenic transformation by v-Src is accompanied by marked morphological changes and cytoskeletal reorganization. Yet, the cytoskeleton-associated proteins with which v-Src interacts are largely unknown. We have studied the binding of v-Src-SH3 domain to cellular proteins utilizing a blot overlay procedure with a GST-v-Src-SH3 fusion protein as probe. A major 62-64 kDa v-Src-SH3-binding protein, present in detergent-insoluble cellular fractions, was identified as p21ras-GTPase-activating protein-associated p62 (GAPA62). In non-transformed cells, including NIH 3T3 cells, GAPA62 was present in both the RIP A-soluble and RIP A-insoluble fractions, but only the latter form was tyrosine-phosphorylated. In contrast, in polyoma middle T antigen-transformed 3T3 cells, GAPA62 was present only in the RIP A-insoluble fraction, where it was highly phosphorylated. It is suggested that tyrosine phosphorylation of GAPA62 may be an important determinant of its cellular localization and its possible function as a mediator of v-Src actions.
Williger
B T
BT
Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel.
Liscovitch
M
M
D016475:3T3 Cells / Q000378:metabolism; D000818:Animals; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000276:immunology / Q000378:metabolism*; D003902:Detergents; D005982:Glutathione Transferase / Q000235:genetics / Q000378:metabolism; D006801:Humans; D015151:Immunoblotting; D051379:Mice; D010750:Phosphoproteins / Q000737:chemistry / Q000276:immunology / Q000378:metabolism*; D010766:Phosphorylation; D019000:Phosphotyrosine / Q000276:immunology; D011233:Precipitin Tests; D016601:RNA-Binding Proteins / Q000737:chemistry / Q000276:immunology / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D012995:Solubility; D014443:Tyrosine / Q000378:metabolism; D018909:src Homology Domains / Q000235:genetics / Q000502:physiology*; D019061:src-Family Kinases / Q000235:genetics / Q000378:metabolism
D004268:DNA-Binding Proteins; C489560:DOK1 protein, human; D003902:Detergents; C489561:Dok1 protein, mouse; C074561:GAP-associated protein p62; D010750:Phosphoproteins; D016601:RNA-Binding Proteins; D011993:Recombinant Fusion Proteins; D019000:Phosphotyrosine; D014443:Tyrosine; D005982:Glutathione Transferase; D019061:src-Family Kinases