Figure 1.

Western blots using anti–caveolin-1 antibodies and/or PY14. (A) Comparison of 3Y1 and SR-3Y1. Anti–α-caveolin-1 antibody (sc-894) reacted with both samples, but PY14 labeled the latter sample alone. The reaction for SR-3Y1 was broad but with prominent bands at 22, 23–24, and 25 kDa. (B) src^ts NRK cells. Reaction with PY14 became detectable only after the cell had been transferred to the permissive temperature. (C) Effect of alkaline phosphatase treatment of nitrocellulose blots of SR-3Y1 lysate. After dephosphorylation, the reactivity with PY14 and anti-phosphotyrosine was lost, whereas the reaction with sc-894 remained. (D) Effect of alkaline phosphatase treatment on immunoprecipitates from SR-3Y1 lysate. Immunoprecipitates obtained with sc-894 were dephosphorylated before being subjected to SDS-PAGE and reacted with sc-894 on blots. Bands above 22 kDa were lost after dephosphorylation. (E) Reactivity of monoclonal anti–caveolin-1 antibodies (clones C060 and 2297) with 3Y1 and SR-3Y1. The antibodies recognize both α and β isoforms in 3Y1 samples, but in SR-3Y1 ones the reaction with the α isoform is much weaker than that with the β isoform.