Fig. 2.

Fos/Jun composition of TH–AP-1 binding protein complexes after TH induction in E14 striatal neurons. A, Autoradiogram of a representative supershift assay of TH–AP-1 binding in rat E14 striatal neurons that were fed DM (Control) or DM containing aFGF and the coactivators. Cultures were generated as described in the Figure 3legend. At 1 hr before the addition of radiolabeled AP-1 probe, either no antibody (None) or 1 μl of antibody to the individual Fos and Jun family members (Santa Cruz Biotechnology) was added to 3 μg of nuclear extract proteins obtained from rat E14 striatal neurons treated with 10 ng/ml aFGF, 20 μm DA, 200 nm TPA, 0.25 mm IBMX, 50 μmforskolin, or control media at 4°C for 1 hr. The protein–DNA complexes were resolved as described in the Figure 3 legend.B, Autoradiogram of a supershift assay of the TH–AP-1 protein complexes formed 6 hr after E14 striatal neurons were stimulated by aFGF and the coactivators. Experiments were conducted with procedures identical to those described in A.C, Immunoblot analysis of control (C) and induced (I) striatal neurons 1 hr after treatment, using the same antibodies as above. Molecular mass (kDa) is indicated by arrows. Two bands of c-Fos immunoreactivity were seen at 62 (band b) and 84 (band a) kDa. c-Jun immunoreactivity was unchanged, whereas Fos-B was increased by stimulation with aFGF and coactivators.