FIG. 3.

(A) Formation of GAF complexes in IFN-stimulated parental and L-C6 cell lines. Results for HeLa and L-C6 cells not treated (−) or treated (+) with IFN-γ are shown. Total cell lysates were analyzed by EMSA using a γ-³²P-labeled hSIEm67 probe. The formation of GAF-specific transcription complexes was verified by incubating the IFN-treated cells with an excess nonradiolabeled hSIEm67 oligonucleotide. The arrow indicates the position of GAF complex. (B) Supershift analysis of GAF complexes, using STAT antibodies. IFN-γ-treated (+) or nontreated (−) HeLa and L-C6 cell extracts were incubated with STAT 1 and STAT 3 antibodies prior to incubation with γ-³²P-labeled hSIEm67 probe and GAF complexes were analyzed by EMSA as mentioned for Fig. 3A. The arrow indicates the presence of the supershifted (S.S) GAF complexes. IgG, immunoglobulin G.