Click on image to view larger version.

Fig. 6. Differential signaling to the PI3K/Akt and RhoA pathway. (A) Akt
phosphorylation. 50 µg of RIPA lysates from mock-transfected CEF or cells
expressing Src527F or the chimeric constructs were resolved by 8%
SDS-PAGE, transferred to PVDF membrane, blocked with 5% nonfat milk/TBS-T, and
probed with an anti-phospho-Akt antibody (top panel) or an anti-Akt antibody
to determine relative protein levels (bottom panel). (B) PI3K assay. 400 µg
of lysates from mock-transfected CEF or cells expressing Src527F or
Y4U32527F were immunoprecipitated with an anti-PI3K antibody and
subjected to PI3K assay as described in Materials and Methods. Kinase assay
products were resolved by thin layer chromatography and visualized by
Phosphorimager analysis (top panel). Anti-PI3K immunoprecipitates were also
resolved by 8% SDS-PAGE, transferred to PVDF membrane, blocked in 5% nonfat
milk/TBS-T, and probed with an anti-PI3K p85 antibody to verify that there
were equal amounts of PI3K in the lysates (bottom panel). (C) RhoA-GTP assay.
CEF cells expressing the chimeric constructs or Src527F were lysed
and 500 µg of cell lysate processed for affinity absorption with GST-Crib,
expressing the Crib domain of rhotekin.