Autoregulation at the level of mRNA 3' end formation of the suppressor of forked gene of Drosophila melanogaster is conserved in Drosophila virilis.
The Drosophila melanogaster Suppressor of forked [Su(f)] protein shares homology with the yeast RNA14 protein and the 77-kDa subunit of human cleavage stimulation factor, which are proteins involved in mRNA 3' end formation. This suggests a role for Su(f) in mRNA 3' end formation in Drosophila. The su(f) gene produces three transcripts; two of them are polyadenylated at the end of the transcription unit, and one is a truncated transcript, polyadenylated in intron 4. Using temperature-sensitive su(f) mutants, we show that accumulation of the truncated transcript requires wild-type Su(f) protein. This suggests that the Su(f) protein autoregulates negatively its accumulation by stimulating 3' end formation of the truncated su(f) RNA. Cloning of su(f) from Drosophila virilis and analysis of its RNA profile suggest that su(f) autoregulation is conserved in this species. Sequence comparison between su(f) from both species allows us to point out three conserved regions in intron 4 downstream of the truncated RNA poly(A) site. These conserved regions include the GU-rich downstream sequence involved in poly(A) site definition. Using transgenes truncated within intron 4, we show that sequence up to the conserved GU-rich domain is sufficient for production of the truncated RNA and for regulation of this production by su(f). Our results indicate a role of su(f) in the regulation of poly(A) site utilization and an important role of the GU-rich sequence for this regulation to occur.
Audibert
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Dynamique du Génome et Evolution, Institut Jacques Monod, Université Denis Diderot, 2, place Jussieu, 75005 Paris, France.
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D000595:Amino Acid Sequence; D000818:Animals; D030801:Animals, Genetically Modified; D001483:Base Sequence; D017124:Conserved Sequence; D004330:Drosophila / Q000235:genetics*; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000235:genetics*; D005091:Exons; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics; D005786:Gene Expression Regulation; D006706:Homeostasis; D006801:Humans; D019476:Insect Proteins / Q000737:chemistry / Q000235:genetics*; D007438:Introns; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D009687:Nuclear Proteins; D012333:RNA, Messenger / Q000235:genetics*; D016601:RNA-Binding Proteins / Q000737:chemistry / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid; D014158:Transcription, Genetic; D039221:mRNA Cleavage and Polyadenylation Factors
D029721:Drosophila Proteins; D005656:Fungal Proteins; D019476:Insect Proteins; D046911:Macromolecular Substances; D009687:Nuclear Proteins; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D029701:Saccharomyces cerevisiae Proteins; D039221:mRNA Cleavage and Polyadenylation Factors; C079745:su(f) protein, Drosophila; C512638:RNA14 protein, S cerevisiae