The effect of dominant-negative RhoA on cell-cycle modulators, cyclin D1 and p21. (A) Immunoblot analysis of cyclin D1 expression levels in ckit⁺ cells transduced with RhoAN19 (lanes 2 and 4) or control vector (lanes 1 and 3). β-Actin levels are used as loading control. Densitometry analysis of cyclin D1 levels normalized to β-actin are shown in the lower panel. One representative blot of at least 3 independent experiments is shown. (B) Immunoblot analysis of p21 expression levels in ckit⁺ cells transduced with RhoAN19 (lanes 2 and 4) or control vector (lanes 1 and 3). β-Actin levels are used as loading control. Densitometry analysis of p21 levels normalized to β-actin are shown in the lower panel. One representative blot of at least 3 independent experiments is shown. (A-B) The cells were either serum starved (lanes 1-2) or stimulated for 9 hours with SCF (lanes 3-4).