Figure 5

Src kinase inhibitor impairs physical interactions between M-cadherin and p120 catenin and their recruitment to lipid rafts. (A) Total lysates (20 μg of proteins) were prepared from Ric10 cells cultured in pmDM for 0 h (lane 1), 24 h (lane 2), 48 h (lane 3), or 67 h (lane 4), and then subjected to immunoblot analysis for the represented proteins. MyHC, myosin heavy chain; p120PY228, tyrosine phosphorylated p120; p120PT310, threonine phosphorylated p120. β-tubulin was used as a loading control. (B) M-cadherin of growing or differentiating Ric10 cells was immunoprecipitated and analyzed by immunoblotting with the appropriate antibodies. (C) p120 catenin was immnoprecipitated from the DRM or non-DRM fractions of differentiating Ric10 cells, and then analyzed by immunoblotting with the appropriate antibodies. (D) M-cadherin was immunoprecipitated from total cell lysates of untreated (Ctrl) or SU6656-treated Ric10 cells (SU), and then analyzed by immunoblotting with the appropriate antibodies. (E) The distribution of M-cadherin and p120 catenin in DRM fractions (30 μl) of untreated or SU6656-treated Ric10 cells was analyzed by immunoblotting with the appropriate antibodies. The distribution of M-cadherin and p120 catenin in DRM was estimated as the relative amount normalized by the amount of flotillin in DRM fractions. Then the distribution of M-cadherin and p120 in DRM fractions of SU6656-treated cells was represented as the % of the amount in DRM fraction of untreated control cells. Averages and standard deviations (n = 3) are shown.