Figure 2.

Activation of p57^KIP2 mRNA expression by p73β. (a) Saos-2p73 cells were untreated (0) or treated with 2 μg/ml doxycycline for the indicated times (hours Dox), and RNA was analyzed by RNase protection. Protected probes specific for p57^KIP2, p27^KIP1, p21^CIP1, and GAPDH are shown. (b) MEFs were transiently transfected with 10 μg of vector control (v), human p73β, or human p73γ expression constructs and harvested 24 h posttransfection. (Upper) Northern blot analysis demonstrating induction of endogenous p57^KIP2 is shown. GAPDH expression was examined as a loading control. (Lower) Expression of p73β and p73γ protein in the same transfected cells by Western blot using an anti-HA antibody.