Figure 5
Effects of dephosphorylation of β1 integrin on its coprecipitation with actin. (A) The β1 integrin immunoprecipitates from quiescent HBE or MCF-7 cells were treated with (+) or without (-) PTP, then immunoblotted with anti-actin, anti-β1 integrin, or anti-PY antibody. The PTP-treated β1 integrin immunoprecipitates from MCF-7 cells were incubated for 30 min with (+) or without (-) the supernatant of the β1 immunoprecipitates containing unbound actin (Cell lysate), or with 5 μg/ml exogenous human platelet actin (A). Molecular size markers are indicated at right in kDa. (B) The β1 integrin immunoprecipitates from quiescent HBE or MCF-7 cells were treated with (+) or without (-) PP2A1, then the PP2A1-treated β1 integrin from MCF-7 cells were incubated for 30 min with (+) or without (-) the supernatant of the β1 immunoprecipitates (Cell lysate), or with 5 μg/ml exogenous human platelet actin (A). The immunoblots were probed with anti-actin, anti-β1 integrin, or anti-PY antibody. Molecular size markers are indicated at right in kDa.