CaMKII binding to β1 integrin in MCF-7 cells. (A) The β1 integrin immunoprecipitates (IP) with the anti-β1 integrin antibody or control IgG from HBE or MCF-7 cells were probed with antibody to all CaMKII isoforms or anti-β1 integrin antibody. Molecular size markers are indicated at right in kDa. (B) The β1 integrin immunoprecipitates from HBE or MCF-7 cells were incubated with the substrate peptide Autocamtide II, calmodulin, inhibitor peptides of PKA and PKC, and [32P]ATP with (closed columns) or without (open columns) 10 μM KN-62 at 30°C for 10 min. After subtraction of the background, the activity was normalized to the amount of β1 integrin and expressed relative to that of the β1 integrin immunoprecipitates from HBE cells without KN-62. Results represent the mean ± S.D. (bars) of duplicate assays of three independent experiments.