FIGURE 2.

Deletion analysis of the human DUSP1 promoter. Fragments of the human DUSP1 5′ region were subcloned into the firefly luciferase reporter construct pGL3b. The positions of GBS elements are indicated by vertical bars. GBS-4.6 comprises three closely spaced GBS elements known as GBS-4.6.1, -4.6.2 and -4.6.3. 200 ng of each reporter construct and 100 ng of a Renilla luciferase expression vector were transiently transfected into HeLa cells, which were then treated for 20 h with vehicle (0.1% ethanol) or Dex (100 nm) before harvesting and measuring luciferase activities. For each construct, firefly luciferase activity was normalized to Renilla luciferase activity, and -fold activation in response to Dex was calculated. In this and subsequent figures, mean -fold responses ± S.E. from three independent experiments are shown. ***, p < 0.001; **, p < 0.01; *, p < 0.05; n.s., not significantly different. Unless otherwise indicated, statistical comparisons are against the largest construct, pGL3b−4834.