Fig. 5.

ISGylation observed with STAT1-dependent upregulation of UBE2L6 in iPSCs following SOCS1 siRNA knockdown.

(A-C) iPSCs were transfected with 50 μM control or SOCS1 siRNA for 48 h (day 0-2), retreated at day two, and treated with 1,000 U/ml of IFNα on day four for 6 h or 24 h (day 5). (A-B) Protein expression for ISG15, ISGylation, UBE1L, UBE2L6, SOCS1, pSTAT1, STAT1, β-actin and OCT4. (C) qPCR analysis of mRNA expression for ISG15, SOCS1, UBE1L, UBE2L6 and STAT1 following 0, 6 or 24 h of IFNα stimulation. Data from repeated experiments in triplicate were averaged and are expressed as mean and standard deviation values (error bar) presented with an unpaired Student’s t test with Welch’s correction used to determine the p values. A p value <0.05 was considered significant. ∗p <0.05, ∗∗p <0.001, ∗∗∗p <0.0001, n.s., non-significant.