Effect of 4-HC on the basal activation of FAK and Rac-1. A. Analysis of samples immunoprecipitated with anti-FAK antibody showed that basal tyrosine phosphorylation of FAK (upper panel) was decreased by 4-HC. The same membrane was stripped and reprobed with anti-paxillin and anti-FAK antibodies. We found no changes on the FAK-bound paxillin levels (middle panel). One representative experiment from 3 is shown. B. The active form of Rac-1 was purified using pull-down assays and then probed with anti-Rac-1 antibody (upper panel). Detection of Rac-1 from total lysates (lower panel) showed that the difference in the amount of active Rac-1 is not associated to changes on its expression. One representative experiment from 2 is shown.