Identification of novel alternative splicing variants of interferon regulatory factor 3
Identification of novel alternative splicing variants of interferon regulatory factor 3
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干扰素调节因子 3 新型选择性剪接变体的鉴定
DOI：
10.1016/j.bbagrm.2011.01.006
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发表时间：
2011-03-01
影响因子：
4.7
通讯作者：
Ke, Yang
中科院分区：
文献类型：
--
作者：
Li, Yong;Hu, Xiuhua;Ke, Yang
干扰素调节因子3（IRF-3）在宿主防御病毒和微生物感染以及细胞生长调节中起着至关重要的作用。IRF-3a是唯一具有结构和功能特征的IRF-3剪接变体，并已被确定拮抗IRF-3活性。在此，鉴定了IRF-3的五种新型剪接变体，称为IRF-3b、-3c、-3d、-3e和-3f，并显示其通过缺失外显子2、3或6或其某种组合产生。RT-PCR检测显示，这些新的剪接变异体更频繁地表达在人类肝脏，食管，宫颈肿瘤组织比在其正常的同行。此外，电泳迁移率变动分析和亚细胞定位显示，只有IRF-3和IRF-3e能够在体外结合干扰素-β（IFN β）启动子的PRDI/III元件，并在Poly（I：C）刺激后发生胞质至核易位。免疫共沉淀实验表明，只有IRF-3c（3f）的新剪接变异体与IRF-3在体内相关。进一步的荧光素酶分析显示IRF-3c（3f）和IRF-3e不能反式激活含PRDI/III的启动子，但似乎在不同程度上抑制IRF-3的反式激活潜力。总之，我们的研究结果表明，新的剪接变异体可能作为IRF-3的负调节剂，并可能与人类肿瘤的发病机制。(C)2011爱思唯尔有限公司版权所有。
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 (IFN beta) 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. (C) 2011 Elsevier B.V. All rights reserved.