Characterization of a novel isoform of murine interferon regulatory factor 3

• Published in: Biochemical and biophysical research communications 2008-12, Vol.377 (2), p.384-388
• Main Authors: Zhai, Jianwei, Gao, Daming, Liu, Wei, Hong, Ran, Qin, Yi, Ouyang, Huafang, Kong, Yuying, Wang, Yuan, Xie, Youhua, Liu, Jing
• Format: Article
• Language: English
• Subjects: Animals; Cell Line; Cell Nucleus - metabolism; Electrophoretic Mobility Shift Assay; Female; IFN-β; Interferon Regulatory Factor-3 - genetics; Interferon Regulatory Factor-3 - metabolism; Interferon-beta - genetics; Liver - metabolism; Mice; Mice, Inbred BALB C; mIRF-3; mIRF-3a; Newcastle Disease - genetics; Newcastle Disease - metabolism; Newcastle disease virus; Promoter Regions, Genetic; Protein Isoforms - genetics; Protein Isoforms - metabolism; Protein Transport; RNA, Messenger - genetics; RNA, Messenger - metabolism; Tissue Distribution; Transcription, Genetic; Transcriptional Activation
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/j.bbrc.2008.09.147

Interferon (IFN) regulatory factors (IRFs) are a family of transcription mediators involved in the regulation of type I IFN (IFN-α/β) transcription. Among the nine already identified IRFs, IRF-3 is a constitutively and ubiquitously expressed and plays a critical role in the transcriptional activation of type I IFN and IFN-stimulated genes including IFN-α1, IFN-β and RANTES. In the present study, we report the identification of a novel alternatively spliced transcript of murine Irf-3 gene (mIrf-3) designated mIRF-3a. mIRF-3a is ubiquitously present in mouse tissues along with mIRF-3 and could be translocated into the nucleus in uninfected L929 cells. EMSA and reporter assay demonstrated that mIRF-3a binds to ISRE sequences in murine Ifn-β promoter and represses Ifn-β promoter activation induced by Newcastle disease virus infection. These results suggest that mIRF-3a may act as a modulator of mIRF-3 functions in vivo.