title: Hrb27C, Sqd and Otu cooperatively regulate gurken RNA localization and mediate nurse cell chromosome dispersion in Drosophila oogenesis.
abstract: Heterogeneous nuclear ribonucleoproteins, hnRNPs, are RNA-binding proteins that play crucial roles in controlling gene expression. In Drosophila oogenesis, the hnRNP Squid (Sqd) functions in the localization and translational regulation of gurken (grk) mRNA. We show that Sqd interacts with Hrb27C, an hnRNP previously implicated in splicing. Like sqd, hrb27C mutants lay eggs with dorsoventral defects and Hrb27C can directly bind to grk RNA. Our data demonstrate a novel role for Hrb27C in promoting grk localization. We also observe a direct physical interaction between Hrb27C and Ovarian tumor (Otu), a cytoplasmic protein implicated in RNA localization. We find that some otu alleles produce dorsalized eggs and it appears that Otu cooperates with Hrb27C and Sqd in the oocyte to mediate proper grk localization. All three mutants share another phenotype, persistent polytene nurse cell chromosomes. Our analyses support dual cooperative roles for Sqd, Hrb27C and Otu during Drosophila oogenesis.
authors.affiliation: Howard Hughes Medical Institute, Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA.
authors.forename: Jennifer S
authors.initials: JS
authors.lastname: Goodrich
authors.forename: K Nicole
authors.initials: KN
authors.lastname: Clouse
authors.forename: Trudi
authors.initials: T
authors.lastname: Schüpbach
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D019521:Body Patterning; D002875:Chromosomes / Q000378:metabolism*; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000033:anatomy & histology / Q000502:physiology*; D005260:Female; D034441:Heterogeneous-Nuclear Ribonucleoproteins / Q000235:genetics / Q000378:metabolism*; D008954:Models, Biological; D009154:Mutation; D009865:Oocytes / Q000502:physiology; D009866:Oogenesis / Q000502:physiology*; D010053:Ovary / Q000166:cytology / Q000502:physiology; D010641:Phenotype; D012313:RNA / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D016211:Transforming Growth Factor alpha / Q000235:genetics / Q000378:metabolism*; D020798:Two-Hybrid System Techniques
chemical_list: D029721:Drosophila Proteins; D034441:Heterogeneous-Nuclear Ribonucleoproteins; C487427:Hrb27C protein, Drosophila; D016601:RNA-Binding Proteins; D016211:Transforming Growth Factor alpha; C083730:grk protein, Drosophila; C061992:otu protein, Drosophila; C081480:sqd protein, Drosophila; D012313:RNA