Fig. 8. MVP expression inhibits STAT1 signaling. Localization of STAT1 in cytosol and nuclei of MVP-transfected (pMVP) and control (pSport6) H65 clones in response to 1000 IU/ml IFN- (1 hour treatment) as indicated was determined by western blot (A) and immunocytochemical (B) analyses. Bar, 10 µm. S6 ribosomal protein (rpS6) was used as cytosolic marker. (C,D) Phosphorylation of STAT1 at Y701 in response to 1000 IU/ml IFN- in the investigated MVP-transfected H65 (C) and the EGFP-MVP transfected VM-48 (D) cell clones was determined by western blot analysis and compared with total STAT1 and MVP expression as indicated. H65 cells were treated with IFN- for 60 minutes and VM-48 cells for 15 and 30 minutes for optimal read-out. All experiments were performed at least twice with comparable results.