RNA helicase A interacts with nuclear factor kappaB p65 and functions as a transcriptional coactivator.
RNA helicase A interacts with nuclear factor kappaB p65 and functions as a transcriptional coactivator.
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DOI：
10.1111/j.1432-1033.2004.04314.x
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发表时间：
2004-09
期刊：
影响因子：
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通讯作者：
T. Tetsuka;Hiroaki Uranishi;T. Sanda;K. Asamitsu;Jiang Yang;F. Wong-Staal;T. Okamoto
中科院分区：
文献类型：
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作者：
T. Tetsuka;Hiroaki Uranishi;T. Sanda;K. Asamitsu;Jiang Yang;F. Wong-Staal;T. Okamoto
RNA解旋酶A(RHA)是含有ATPase活性的DNA和RNA解旋酶家族的成员，参与转录和mRNA输出等基因表达的多个步骤。据报道，RHA直接与转录辅助激活蛋白CREB结合蛋白和肿瘤抑制蛋白BRCA1结合，并将它们连接到RNA聚合酶II全酶复合体。通过酵母双杂交筛选，我们已经确定RHA是核因子kappaB的p65亚单位(NF-kappaB)的相互作用分子。体外谷胱甘肽-S转移酶下拉实验和体内免疫共沉淀实验证实了p65与rHA的相互作用。瞬时转染实验中，RHA可增强p65、肿瘤坏死因子-α或核因子-kappaB诱导的报告基因表达。缺乏ATP结合活性的突变型RHA抑制了这些激活剂诱导的NF-kappaB依赖的报告基因的表达。此外，使用短干扰RNA耗尽RHA可减少依赖于NF-kappaB的反式激活。这些数据表明，RHA是转录激活复合体的重要组成部分，它介导了核因子-kappaB的转录活性。
RNA helicase A (RHA), a member of DNA and RNA helicase family containing ATPase activity, is involved in many steps of gene expression such as transcription and mRNA export. RHA has been reported to bind directly to the transcriptional coactivator, CREB-binding protein, and the tumor suppressor protein, BRCA1, and links them to RNA Polymerase II holoenzyme complex. Using yeast two-hybrid screening, we have identified RHA as an interacting molecule of the p65 subunit of nuclear factor kappaB (NF-kappaB). The interaction between p65 and RHA was confirmed by glutathione-S transferase pull-down assay in vitro, and by co-immunoprecipitation assay in vivo. In transient transfection assays, RHA enhanced NF-kappaB dependent reporter gene expression induced by p65, tumor necrosis factor-alpha, or NF-kappaB inducing kinase. The mutant form of RHA lacking ATP-binding activity inhibited NF-kappaB dependent reporter gene expression induced by these activators. Moreover, depletion of RHA using short interfering RNA reduced the NF-kappaB dependent transactivation. These data suggest that RHA is an essential component of the transactivation complex by mediating the transcriptional activity of NF-kappaB.