FIG. 6.

Flag-p37 expression inhibits cycloheximide-mediated stabilization of ARE-mRNA decay. (A) CHO cells were cotransfected with Flag-p37 AUF1 or vector alone, along with β-Gal reporter plasmid DNAs. At 24 h posttransfection, cells were treated with 100 μg of cycloheximide (CHX)/ml for 4 h prior to isolation of total RNA and Northern blot analysis. Autoradiograms were quantified by densitometry, β-Gal mRNA levels were normalized to the GFP control mRNA, and levels were expressed relative to that of the untreated and untransfected control GC-mRNA, which was set at 100%. (B) Untransfected (left) and Flag-p37-transfected (right) CHO cells were treated with CHX and then used to prepare whole-cell lysates. Equal amounts of total protein were resolved by SDS-PAGE and immunoblotted for endogenous AUF1 or Flag. The blot was stripped and reprobed with an antibody specific for tubulin or GFP to verify equal loading. Representative blots are shown.