title: The RNA binding complexes NF45-NF90 and NF45-NF110 associate dynamically with the c-fos gene and function as transcriptional coactivators.
abstract: The c-fos gene is rapidly induced to high levels by various extracellular stimuli. We used a defined in vitro transcription system that utilizes the c-fos promoter to purify a coactivator activity in an unbiased manner. We report here that NF45-NF90 and NF45-NF110, which possess archetypical double-stranded RNA binding motifs, have a direct function as transcriptional coactivators. The transcriptional activities of the nuclear factor (NF) complexes (NF45-NF90 and NF45-NF110) are mediated by both the upstream enhancer and core promoter regions of the c-fos gene and do not require their double-stranded RNA binding activities. The NF complexes cooperate with general coactivators, PC4 and Mediator, to elicit a high level of transcription and display multiple interactions with activators and the components of the general transcriptional machinery. Knockdown of the endogenous NF90/NF110 in mouse cells shows an important role for the NF complexes in inducing c-fos transcription. Chromatin immunoprecipitation assays demonstrate that the NF complexes occupy the c-fos enhancer/promoter region before and after serum induction and that their occupancies within the coding region of the c-fos gene increase in parallel to that of RNAPII upon serum induction. In light of their dynamic occupancy on the c-fos gene as well as direct functions in both transcription and posttranscriptional processes, the NF complexes appear to serve as multifunctional coactivators that coordinate different steps of gene expression to facilitate rapid response of inducible genes.
authors.affiliation: From the Department of Molecular Biology, Faculty of Medicine, Saitama Medical University, 38 Morohongo, Moroyama, Iruma-gun, Saitama 350-0495, Japan and.
authors.forename: Tomoyoshi
authors.initials: T
authors.lastname: Nakadai
authors.affiliation: Department of Biochemistry, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan.
authors.forename: Aya
authors.initials: A
authors.lastname: Fukuda
authors.affiliation: From the Department of Molecular Biology, Faculty of Medicine, Saitama Medical University, 38 Morohongo, Moroyama, Iruma-gun, Saitama 350-0495, Japan and.
authors.forename: Miho
authors.initials: M
authors.lastname: Shimada
authors.affiliation: Department of Biochemistry, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan.
authors.forename: Ken
authors.initials: K
authors.lastname: Nishimura
authors.affiliation: Department of Biochemistry, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan kojihisa@md.tsukuba.ac.jp.
authors.forename: Koji
authors.initials: K
authors.lastname: Hisatake
mesh_terms: D000818:Animals; D016367:Baculoviridae / Q000235:genetics; D001665:Binding Sites; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D005786:Gene Expression Regulation; D016762:Genes, fos; D006367:HeLa Cells; D006801:Humans; D007700:Kinetics; D056892:Mediator Complex / Q000235:genetics / Q000378:metabolism; D051379:Mice; D051903:Nuclear Factor 45 Protein / Q000235:genetics* / Q000378:metabolism; D050779:Nuclear Factor 90 Proteins / Q000235:genetics* / Q000378:metabolism; D010957:Plasmids / Q000737:chemistry / Q000378:metabolism; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D012319:RNA Polymerase II / Q000235:genetics* / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D061987:Sf9 Cells; D015398:Signal Transduction; D018411:Spodoptera; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic
chemical_list: D004268:DNA-Binding Proteins; C494013:ILF2 protein, human; C429643:ILF3 protein, human; D056892:Mediator Complex; D051903:Nuclear Factor 45 Protein; D050779:Nuclear Factor 90 Proteins; D011994:Recombinant Proteins; C509201:SUB1 protein, human; D014157:Transcription Factors; D012319:RNA Polymerase II
keywords: RNA binding protein; c-Fos; gene regulation; transcription; transcription coactivator