Figure 5.

(A) Immunoblot analysis of tetracycline (Tet) responsiveness of several stable DMS53-Id1 clones. (B) Id1-overexpressing clones (Id16 and Id17) were incubated in the presence of 30 ng/ml of tetracycline overnight, and then incubated for 8 h in the presence of different concentrations of tetracycline. Expressions of Mash1 and Id1 were analyzed by immunoblotting. (C) Parental and two Id1-overexpressing clones (Id16 and Id17) were incubated overnight with 30 ng/ml of tetracycline in order to block ectopic Id1 expression. Then cells were deprived of tetracycline for the times indicated and expressions of Mash1 and Id1 were analyzed by immunoblotting.