title: Cotranscriptional splicing potentiates the mRNA production from a subset of estradiol-stimulated genes.
abstract: While early steps of gene expression, such as transcription preinitiation, are known to often be rate limiting and to be regulated by such stimuli as steroid hormones, the potential impact of downstream steps, including splicing, on the mRNA production rate is unknown. In this work, we studied the effects of the transcriptional stimulus estradiol on cyclin D1, PS2, and c-fos gene expression by measuring the levels of RNA polymerase II on the DNA templates, the levels of nascent transcripts associated with RNA polymerase II, and the levels of unspliced, partially spliced, and fully spliced RNAs. We demonstrated that the efficiency of cotranscriptional splicing of the first intron was higher in the case of cyclin D1 than with PS2 and potentiated the cyclin D1 mRNA production rate. The mechanism involved in cotranscriptional splicing depended on the level of serine 5 phosphorylation of RNA polymerase II at the gene 5' end and on the recruitment of CBP80, one of the two subunits of the cap binding complex, which stimulates splicing of the promoter-proximal intron. Our data indicate that mRNA production from a subset of estradiol-stimulated genes, such as cyclin D1, could occur in a very efficient "assembly line." In contrast, we demonstrated for the first time that despite a strong transcriptional activation of the PS2 gene, the production of mRNA is not optimized owing to inefficient cotranscriptional RNA processing.
authors.affiliation: INSERM U685, Institut Universitaire d'Hematologie, Hopital Saint-Louis, 1 Avenue Claude Vellefaux, 75010 Paris, France.
authors.forename: Danielle
authors.initials: D
authors.lastname: Bittencourt
authors.forename: Martin
authors.initials: M
authors.lastname: Dutertre
authors.forename: Gabriel
authors.initials: G
authors.lastname: Sanchez
authors.forename: Jérôme
authors.initials: J
authors.lastname: Barbier
authors.forename: Lise
authors.initials: L
authors.lastname: Gratadou
authors.forename: Didier
authors.initials: D
authors.lastname: Auboeuf
mesh_terms: D000818:Animals; D002460:Cell Line; D019938:Cyclin D1 / Q000235:genetics / Q000378:metabolism; D004958:Estradiol / Q000378:metabolism / Q000494:pharmacology*; D005786:Gene Expression Regulation / Q000187:drug effects*; D006801:Humans; D007438:Introns; D016760:Proto-Oncogene Proteins c-fos / Q000235:genetics / Q000378:metabolism; D012319:RNA Polymerase II / Q000378:metabolism; D012326:RNA Splicing; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D012694:Serine / Q000378:metabolism; D014158:Transcription, Genetic / Q000187:drug effects*; D000071163:Trefoil Factor-1; D025521:Tumor Suppressor Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D016760:Proto-Oncogene Proteins c-fos; D012333:RNA, Messenger; C051838:TFF1 protein, human; D000071163:Trefoil Factor-1; D025521:Tumor Suppressor Proteins; D019938:Cyclin D1; D012694:Serine; D004958:Estradiol; D012319:RNA Polymerase II