Figure 2.

Only Fos-Containing AP-1 Dimers Are Trans-Repressed by GR

A, CEFs were cotransfected with pRSV-GR together with either the 5xcoll-TRE-TATA-luciferase reporter gene and an expression vector for the c-Fos seeking c-Jun mutant (c-Jun-m0) or the 5xjun2-TATA-luciferase reporter gene and an expression vector for the ATF2 seeking c-Jun mutant (c-Jun-m1). Luciferase activities were determined after treatment with dexamethasone (Dex) or solvent and are plotted as fold induction (mean ± sd of five independent experiments). B and C, HeLa cells were transiently cotransfected with the −1977/−1858uPA-TATA-luciferase reporter gene and Ubi-Renilla, together with expression vectors for either c-Jun-m0 and c-Fos or c-Jun-m1 and ATF2 (B) or expression vectors for either the single-chain AP-1 c-Jun∼c-Fos (cJ∼cF) or the single-chain AP-1 c-Jun∼ATF2 (cJ∼A) (C). Cells were treated with dexamethasone (Dex) as indicated. Luciferase activities normalized to Renilla activities are plotted as fold induction (mean ± sd of one representative experiment performed in triplicate; *, P < 0.05). D, HeLa cells were transiently cotransfected with either the −517/+63-collagenaseI-luciferase reporter gene (Coll-Luc) or the 5xjun2-TATA-luciferase reporter gene, together with the indicated single-chain AP-1. Normalized luciferase activities were determined after treatment with dexamethasone (Dex) or solvent and are plotted as fold induction (mean ± sd of one representative experiment performed in triplicate).