Related Experiment Video
Updated: Jun 4, 2026

Merging Absolute and Relative Quantitative PCR Data to Quantify STAT3 Splice Variant Transcripts
Published on: October 9, 2016
Identification of novel alternative splicing variants of interferon regulatory factor 3
Yong Li1, Xiuhua Hu, Yuqin Song
1Key laboratory of Carcinogenesis and Translational Research, Department of Genesis, Peking University School of Oncology , Beijing Cancer Hospital & Institute, Beijing, PR China.
Abstract:
Interferon regulatory factor 3 (IRF-3) plays a crucial role in host defense against viral and microbial infection as well as in cell growth regulation. IRF-3a is the only structurally and functionally characterized IRF-3 splicing variant and has been established to antagonize IRF-3 activity. Here, five novel splicing variants of IRF-3, referred to as IRF-3b, -3c, -3d, -3e, and -3f, were identified and shown to be generated by deletion of exons 2, 3, or 6 or some combination thereof. RT-PCR examination revealed that these novel splicing variants were more frequently expressed in human liver, esophagus, and cervical tumor tissues than in their normal counterparts. Additionally, electrophoretic mobility shift assay and subcellular localization showed only IRF-3 and IRF-3e were capable of binding the PRDI/III element of interferon-beta (IFNβ) promoter in vitro and underwent cytoplasm-to-nucleus translocation following Poly(I:C) stimulation. Coimmunoprecipitation assay revealed that only IRF-3c (3f) of novel splicing variants associated with IRF-3 in vivo. Further luciferase assay showed IRF-3c (3f) and IRF-3e failed to transactivate PRDI/III-containing promoter but appeared to inhibit transactivation potential of IRF-3 to varying degrees. Taken together, our findings suggest novel splicing variants may function as negative modulators of IRF-3 and may be correlated with pathogenesis of human tumors.
Related Concept Videos
Alternative RNA Splicing
There are five types of alternative RNA splicing that vary in the ways the pre-mRNA segments are removed or retained in the mature mRNA. The first...
Alternative RNA Splicing
There are five types of alternative RNA splicing that vary in the ways the pre-mRNA segments are removed or retained in the mature mRNA. The first...
RNA Splicing
RNA Splicing
Leaky Scanning
Pre-mRNA Processing: RNA Splicing

