Figure 3. JAK1-STAT1 signaling is required for IFN1@-induced autophagy. (A–C) K562 cells were treated with IFN1@ (1000 U/ml) for 48 h in the presence or absence of AG-490 (10 μM). Then P-STAT1 was assayed by western blot (A). STAT1 transcriptional activity was assayed by a luciferase reporter system. Control group was set as 100%. (B) Autophagy was assayed by quantitation of average number of LC3 puncta per cell (C). n = 3, *p < 0.05. (D and E) K562 cells were transfected with JAK1 and STAT1 shRNA for 48 h, and then treated with IFN1@ (1000 U/ml, 48 h) or starvation (HBSS, 2 h). Autophagy was assayed by western blot analysis of LC3 expression (D) or quantitation of average number of LC3 puncta per cell (E). n = 3, *p < 0.05 vs. control shRNA group.