The suppressor of forked gene of Drosophila, which encodes a homologue of human CstF-77K involved in mRNA 3'-end processing, is required for progression through mitosis.
The Suppressor of forked (Su(f)) protein of Drosophila melanogaster is a homologue of the 77K subunit of human cleavage stimulation factor required for cleavage of pre-mRNAs before addition of poly(A). We have previously shown that the Su(f) protein is not ubiquitously distributed: it accumulates in dividing cells at various stages of Drosophila development. In this paper, we show that phenotypes of su(f) temperature-sensitive mutants result from a defect in cell proliferation. Analysis of the mitotic phenotype of su(f) temperature-sensitive alleles in larval brain and in imaginal discs reveals an increase in the number of metaphases with overcondensed chromosomes and asymmetric or reduced mitotic spindles. In contrast, neural differentiation in eye imaginal discs of the same mutant flies does not appear to be affected. These results indicate that su(f) is required during cell division for progression through metaphase. Taken together, these data suggest that a decrease in su(f) activity preferentially affects 3'-end formation of particular mRNAs, some of which are involved in mitosis, and are in agreement with a role of su(f) in the regulation of poly(A) site utilization.
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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D000818:Animals; D001921:Brain / Q000254:growth & development; D002453:Cell Cycle / Q000235:genetics; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000166:cytology / Q000235:genetics* / Q000378:metabolism; D005123:Eye / Q000254:growth & development; D005260:Female; D017344:Genes, Insect; D006801:Humans; D019476:Insect Proteins / Q000235:genetics* / Q000378:metabolism; D008297:Male; D008938:Mitosis / Q000235:genetics*; D009154:Mutation; D009687:Nuclear Proteins; D010641:Phenotype; D012322:RNA Precursors / Q000378:metabolism; D012323:RNA Processing, Post-Transcriptional; D016601:RNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D039221:mRNA Cleavage and Polyadenylation Factors
D029721:Drosophila Proteins; D019476:Insect Proteins; D009687:Nuclear Proteins; D012322:RNA Precursors; D016601:RNA-Binding Proteins; D039221:mRNA Cleavage and Polyadenylation Factors; C079745:su(f) protein, Drosophila