Stat1-binding site alone is not sufficient to drive IFN-γ–inducible transcription of FcγRI gene.

(A) Schematic diagram of the reporter constructs. (B) RAW264.7 cells were transfected with different reporter constructs, and luciferase activity was measured after 6 hours of treatment with IFN-γ. (C) The same reporter constructs as in panel B were analyzed in U3A cells. U3A cells were transfected with 1 μg reporter, 0.5 μg β-galactosidase plasmid, 250 ng Stat1, and 50 ng PU.1 and either not stimulated or stimulated with IFN-γ for 6 hours before measurement of luciferase activity. (D) RAW264.7 cells were transfected with 189/66-TATAluc or 189/66-ΔPU.1-TATAluc and analyzed as in shown in panel B. Values shown (± SD) are from 3 different experiments.