Immunofluorescence localization of phosphotyrosine containing proteins in RSV-transformed mouse fibroblasts.
The localization of phosphotyrosine-containing proteins (P-TYR proteins) was studied by immunofluorescence microscopy employing affinity-purified azobenzyl phosphonate (ABP) antibodies, which specifically cross-react with phosphotyrosine. In Rous sarcoma virus (RSV)-transformed fibroblasts, after fixation followed by permeabilization with nonionic detergents, ABP antibodies gave a diffuse staining of the cytoplasm and specifically decorated restricted areas of the ventral plasma membrane corresponding to adhesion plaques, identified by interference reflection microscopy and staining with anti-vinculin serum. Specific decoration was also observed at the level of cell-cell contacts and at the tips of filopodial protrusions. Control non-transformed 3T3 mouse fibroblasts were not significantly stained by ABP antibodies. These findings show that, in RSV-transformed cells, proteins phosphorylated at tyrosine residues are found at cell-substratum and cell-cell contacts.
D000818:Animals; D000906:Antibodies; D000936:Antigen-Antibody Complex; D001358:Avian Sarcoma Viruses / Q000235:genetics*; D002460:Cell Line; D002471:Cell Transformation, Neoplastic; D003429:Cross Reactions; D005347:Fibroblasts / Q000032:analysis; D005455:Fluorescent Antibody Technique; D051379:Mice; D008807:Mice, Inbred BALB C; D010750:Phosphoproteins / Q000032:analysis* / Q000302:isolation & purification; D019000:Phosphotyrosine; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000032:analysis
D000906:Antibodies; D000936:Antigen-Antibody Complex; D010750:Phosphoproteins; D019000:Phosphotyrosine; D014443:Tyrosine