Fig. 5.

KSRP negatively regulates gene expression via the TNF-α 3′ UTR. A: Schematic figure of the luciferase reporters used showing the ARE portion of the TNF-α 3′UTR or the antisense control UTR downstream from the luciferase gene. B: The upper panel is a Western blot of WT astrocytes transfected with increasing amounts of FLAG-KSRP or myc-hnRNPC control plasmids (see Materials and Methods). The blot was probed with an anti-FLAG (KSRP) or anti-myc (hnRNP C) antibody. The lower panel shows relative luciferase activities of the reporters following co-transfection with increasing amounts of expression plasmid (1–3 μg) versus reporter plasmid (1 μg). After normalizing to the transfection control (β-galactosidase), all values were expressed as a percent of the luciferase activity when the reporter was co-transfected with pcDNA alone. The 3′ UTR tested is shown in parentheses. All data points represent the mean (±SEM) of three independent experiments. **P < 0.003, **** P <0.0001, comparing TNF-α to control 3′ UTR for KSRP.