FIG. 4.
Translation of TOP mRNAs is normally regulated in PKBα−/− MEF cells. (a) PKBα+/+ and PKBα−/− MEF were harvested after being serum starved for 44 h without or with 1 or 3 h of serum refeeding. The polysomal distribution of the mRNAs encoding PKBα, rpL32, and actin was analyzed and presented as described in the legend to Fig. 1. (b) Cytoplasmic proteins from PKBα+/+ (+/+) and PKBα−/− (−/−) MEF were harvested after being serum starved for 44 h without (−) or with 1 h of serum refeeding (+) and subjected to Western blot analysis. Bottom panel, immunoblotting with anti-PKB. Top panel, Ponceau S-stained membrane, showing the relative protein loading among samples. Note that the three PKB isoforms contain similar numbers of amino acids (from 466 to 481 residues).