FIG. 2.
TGF-α induces tyrosine phosphorylation of amastigote proteins. Amastigotes (5 × 106 organisms) were incubated with TGF-α (2 ng/ml) for 5, 15, and 30 min at 4°C. Lysate samples (10 μg) were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, blotted onto nitrocellulose, probed with antiphosphotyrosine monoclonal antibody PY20, and developed by chemiluminescence. Control parasites did not receive any growth factor. Blots were stripped, probed with anti-β-actin antibodies, and developed by chemiluminescence as a loading control. Results are from a representative experiment of three performed independently with similar results. Arrows point to enhanced protein tyrosine phosphorylation induced by TGF-α with respect to controls in the absence of growth factor treatment.