title: RNA helicase A interacts with nuclear factor kappaB p65 and functions as a transcriptional coactivator.
abstract: 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.
authors.affiliation: Department of Molecular and Cellular Biology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Aichi, Japan.
authors.forename: Toshifumi
authors.initials: T
authors.lastname: Tetsuka
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Uranishi
authors.forename: Takaomi
authors.initials: T
authors.lastname: Sanda
authors.forename: Kaori
authors.initials: K
authors.lastname: Asamitsu
authors.forename: Jiang-Ping
authors.initials: JP
authors.lastname: Yang
authors.forename: Flossie
authors.initials: F
authors.lastname: Wong-Staal
authors.forename: Takashi
authors.initials: T
authors.lastname: Okamoto
mesh_terms: D001324:Autoantigens / Q000378:metabolism*; D015153:Blotting, Western; D002384:Catalysis; D002460:Cell Line; D053487:DEAD-box RNA Helicases; D015870:Gene Expression; D017930:Genes, Reporter; D006801:Humans; D016328:NF-kappa B / Q000737:chemistry / Q000378:metabolism*; D009363:Neoplasm Proteins; D011233:Precipitin Tests; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D021122:Protein Subunits / Q000378:metabolism*; D020365:RNA Helicases / Q000378:metabolism*; D034622:RNA Interference; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics; D015534:Trans-Activators / Q000378:metabolism*; D014158:Transcription, Genetic; D015533:Transcriptional Activation; D020798:Two-Hybrid System Techniques
chemical_list: D001324:Autoantigens; D016328:NF-kappa B; D009363:Neoplasm Proteins; D021122:Protein Subunits; D011993:Recombinant Fusion Proteins; D015534:Trans-Activators; C098487:DHX9 protein, human; D053487:DEAD-box RNA Helicases; D020365:RNA Helicases