Fig. 3.

Stimulation of IL-6 gene transcription by membrane depolarization is mediated by the GRE2 in the IL-6 promoter.A, Scheme of the human IL-6 promoter. B, PC-12 cells were transfected with reporter gene constructs containing mutations in the indicated promoter elements. Basal luciferase expression was affected by the mutations as follows [percent of wild-type (wt) expression]: wt, 100.0 ± 15.9; mGRE2, 77.0 ± 42.9; mGRE1, 11.1 ± 1.9; mutated TPA response element (mTRE), 74.6 ± 16.9; mutated multiple response element (mMRE), 76.5 ± 34.8; mCAAT, 78.1 ± 35.6; m2κB, 51.4 ± 17.8; m2κB, 24.0 ± 5.8. *p < 0.05 compared with wtIL6Luc stimulated with 45 mm KCl. C, Cerebellar granule cells were transfected with reporter gene constructs containing either the wild-type IL-6 promoter or the IL-6 promoter with a mutation in the GRE2. *p < 0.05 compared with the untreated control. D, Mutation of the GRE2 had no effect on IL-6 gene transcription in primary astrocytes that were stimulated by mobilization of intracellular Ca²⁺ with 1 μm thapsigargin. Controls and stimulated cells were treated with 333 nm12-O-tetradecanoylphorbol-13-acetate. Data are mean ± SEM values of at least three independent experiments, each done in duplicate.