First Author | Yang H | Year | 2003 |
Journal | J Biol Chem | Volume | 278 |
Issue | 18 | Pages | 15495-504 |
PubMed ID | 12604599 | Mgi Jnum | J:83214 |
Mgi Id | MGI:2658753 | Doi | 10.1074/jbc.M212940200 |
Citation | Yang H, et al. (2003) Interferon regulatory factor-7 synergizes with other transcription factors through multiple interactions with p300/CBP coactivators. J Biol Chem 278(18):15495-504 |
abstractText | Interferon regulatory factor (IRF)-7 is activated in response to virus infection and stimulates the transcription of a set of cellular genes involved in host antiviral defense. The mechanism by which IRF-7 is activated and cooperates with other transcription factors is not fully elucidated. Activation of IRF-7 results from a conformational change triggered by the virus-dependent phosphorylation of its C terminus. This conformational change leads to dimerization, nuclear accumulation, DNA-binding, and transcriptional transactivation. Here we show that activation of IRF-7, like that of IRF-3, is dependent on modifications of two distinct sets of Ser/Thr residues. Moreover, we show that different virus-inducible cis-acting elements display requirements for specific IRFs. In particular, the virus-responsive element of the ISG15 gene promoter can be activated by either IRF-3 or IRF-7 alone, whereas the P31 element of the interferon-beta gene is robustly activated only when IRF-3, IRF-7, and the p300/CBP coactivators are all present. Furthermore, we find that IRF-7 interacts with four distinct regions of p300/CBP. These interactions not only stimulate the intrinsic transcriptional activity of IRF-7, but they are also indispensable for its ability to strongly synergize with other transcription factors, including c-Jun and IRF-3. |