The Ubiquitin-Specific Protease 18 Promotes Hepatitis C Virus Production by Increasing Viral Infectivity

Figure 3

USP18 has no inhibitory effect on Jak/STAT signaling in Huh7.5 cells. Huh7.5 cells were seeded at /ml, 2 ml per well in 6-well plates in antibiotic-free medium for 24 hours before 4 μg blank vector pcDNA-DEST53, 4 μg USP18 WT, or 4 μg USP18 C64S was transfected into each well. 36 hours posttransfection, 100 IU/ml IFNα was added to each well. The cells were harvested at 0 min, 30 min, 2 hours, 4 hours, and 8 hours posttreatment. Total protein was extracted to detect USP18, phospho-STAT1 (Tyr701), and total STAT1 by western blot (a, upper), and phospho-STAT1 integrated density was normalized by STAT1 (a, bottom). Total RNA was extracted to detect ISG mRNAs by real-time PCR (b). V: transfected with 4 μg blank vector pcDNA-DEST53; WT: transfected with 4 μg USP18 WT; mu: transfected with 4 μg USP18 C64S. Results are presented as ().

(a)

(b)