Figure 6.

Effect of ATF3 on Cdk activity and the expression of various cell cycle regulators. (A) Cdk4 and Cdk2 kinase activities of c-myc-deficient cells treated with AdATF3 and serum for 48 h were assayed from lysates of exponentially growing cells, as previously reported (Tamamori-Adachi et al, 2004). The activities were normalized to the amount of Cdk4 and Cdk2. (B) Cell cycle regulators were measured by Western blot analysis at each time point after serum stimulation of c-myc-deficient cells infected with AdLacZ or AdATF3 (25 MOI) for 48 h. Immunoblots of tubulin are shown as control.