Genome-wide gene expression analysis of FAF1 silencing in HeLa cells

This study is designed to examine the cellular functions of human Fas-associated factor 1 (FAF1) containing multiple ubiquitin-related domains. Microarray analyses revealed that interferon stimulated genes related to antiviral response are significantly increased in FAF1 knocked down HeLa cells. Silencing FAF1 enhanced the poly I:C and respiratory syncytial virus (RSV) induced productions of type I interferons (IFNs), the target gene of interferon regulator factor 3 (IRF3). IRF3 is a key transcription factor in IFNβ signaling responsible for host innate immune response. This study also found that FAF1 and IRF3 physically associate with IPO5/importin-β3 and that overexpression of FAF1 reduces the interaction between IRF3 and IPO5/importin-β3. These findings suggest that FAF1 negatively regulates IRF3-mediated IFNβ production and antiviral innate immune response via regulating nuclear translocation of IRF3. We conclude that FAF1 plays a novel role negatively regulating virus-induced IFNβ production and antiviral response by inhibiting the translocation of active phosphorylated IRF3 from cytosol to nucleus. HeLa cells were transfected with control siRNA or FAF1 siRNA. After 48 h, cells were harvested and total RNA were purified. Biotin labeled cRNA were hybridized to each Huamn HT12 expression v.4 bead array. Data analysis was performed using manufacturer's software.