FIG. 4.

Association of ISGF3 with other Mediator subunits. (A) SRB10 coprecipitates STAT2. Coimmunoprecipitation analysis was carried out as described in the legend to Fig. 3, except that a FLAG-SRB10 stably transformed cell line was used and immunoprecipitations were performed with FLAG antibody. (B) IFN-dependent, indirect recruitment of DRIP130 to ISG54 promoter. The ChIP assay was carried out as described in the legend to Fig. 3, except that HeLa cells that were unstimulated (0) or treated with IFN for 30 min (30) were used. Cont, control. (C) IFN-dependent RNA polymerase II (Pol II) recruitment to ISG54 promoter. The ChIP assay was carried out with antisera specific for the RNA polymerase II CTD. Input = 5% of DNA prior to precipitation.