A role for Rac1 and Cdc42 in focus reconstruction. (a) Cells were grown in the presence or absence of tetracycline (1 μg/ml). PH3MT-tTak-C1 is the parental cell strain. PH3MT-VC-C2 is transfected with empty vector. Whole cell extracts were made and the Western blot was probed with both myc and FLAG antibodies. β-actin levels were used to indicate loading. (b) Cells expressing dominant negative mutants were plated on a lawn of non-transformed MSU-1.1 cells, and focus reconstruction was analyzed. Pictures are representative of replicate experiments.