Induction of GADD34 Is Necessary for dsRNA-Dependent Interferon-β Production and Participates in the Control of Chikungunya Virus Infection
Figure 2
PKR is required for ATF4 and GADD34 expression in response to poly I:C.
A) WT and PKR−/− MEFs were stimulated for 8 h with poly I:C (pI:C), or the UPR-inducing drug, thapsigargin (th) for 6 h. ATF4 protein expression was detected by immunoblot on nuclear extracts. Nuclear HDAC1 immunoblot is shown for equal loading control. * indicates unspecific band. B) GADD34 mRNA levels were quantified by qPCR after 6 h of poly I:C (pI:C) treatment in WT and PKR−/− MEFs. For the same cell extracts, immunoblots of GADD34 (middle panel), PKR and P-eIF2α (right panel) were performed. C) The same analysis was performed in eIF2α A/A and control eIF2α S/S MEFs. Treatment with thapsigargin (th), for 6 h was used as control to induce GADD34 and P-eIF2α. eIF2α and β-actin immunoblots are shown for equal loading control. Quantitative PCR data are the mean ± standard deviation of 3 independent experiments.