FIG. 3.

Dexamethasone sensitivity is conferred by a short, AU-rich region of the Cox-2 3′ UTR. Transfections and RNase protection assays were performed as described in the legend to Fig 2, using the reporter constructs pTetBBB-Cox1.4, pTetBBB-Cox0.6, pTetBBB-Cox0.5, and pTetBBB-Cox0.1. Dexamethasone (Dex) (1 μM) was added 22 h after the transfection, and tetracycline (Tet) was added after a further 2 h. (A) Representative experiments. Only the β-globin reporter and GAPDH loading control are shown. (B) Graphical representation of the experiments in panel A. Each transfection was performed at least twice, with qualitatively identical results. (C) Sequence of the 123-nucleotide p38-responsive region of the Cox-2 3′ UTR. AUUUA repeats are indicated by horizontal bars.