title: The Drosophila hnRNPA/B homolog, Hrp48, is specifically required for a distinct step in osk mRNA localization.
abstract: The Staufen-dependent localization of oskar mRNA to the posterior of the Drosophila oocyte induces the formation of the pole plasm, which contains the abdominal and germline determinants. In a germline clone screen for mutations that disrupt the posterior localization of GFP-Staufen, we isolated three missense alleles in the hnRNPA/B homolog, Hrp48. These mutants specifically abolish osk mRNA localization, without affecting its translational control or splicing, or the localization of bicoid and gurken mRNAs and the organization of the microtubule cytoskeleton. Hrp48 colocalizes with osk mRNA throughout oogenesis, and interacts with its 5' and 3' regulatory regions, suggesting that it binds directly to oskar mRNA to mediate its posterior transport. The hrp48 alleles cause a different oskar mRNA localization defect from other mutants, and disrupt the formation of GFP-Staufen particles. This suggests a new step in the localization pathway, which may correspond to the assembly of Staufen/oskar mRNA transport particles.
authors.affiliation: The Wellcome Trust/Cancer Research UK, Gurdon Institute and Department of Genetics, Cambridge University, Tennis Court Road, Cambridge CB2 1QR, United Kingdom.
authors.forename: Jean-René
authors.initials: JR
authors.lastname: Huynh
authors.forename: Trent P
authors.initials: TP
authors.lastname: Munro
authors.forename: Katia
authors.initials: K
authors.lastname: Smith-Litière
authors.forename: Jean-Antoine
authors.initials: JA
authors.lastname: Lepesant
authors.forename: Daniel
authors.initials: D
authors.lastname: St Johnston
mesh_terms: D020413:3' Untranslated Regions / Q000235:genetics; D000818:Animals; D001665:Binding Sites / Q000235:genetics; D002352:Carrier Proteins / Q000235:genetics; D002451:Cell Compartmentation / Q000235:genetics; D016764:Cell Polarity / Q000235:genetics; D029721:Drosophila Proteins / Q000096:biosynthesis / Q000235:genetics*; D004331:Drosophila melanogaster / Q000166:cytology / Q000196:embryology* / Q000235:genetics*; D034481:Heterogeneous-Nuclear Ribonucleoprotein Group A-B / Q000235:genetics*; D034441:Heterogeneous-Nuclear Ribonucleoproteins / Q000235:genetics*; D018398:Homeodomain Proteins / Q000235:genetics; D020125:Mutation, Missense / Q000235:genetics; D009865:Oocytes / Q000166:cytology / Q000254:growth & development* / Q000378:metabolism; D009866:Oogenesis / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics; D016601:RNA-Binding Proteins / Q000235:genetics; D017385:Sequence Homology; D015534:Trans-Activators / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics; D016211:Transforming Growth Factor alpha / Q000235:genetics
chemical_list: D020413:3' Untranslated Regions; D002352:Carrier Proteins; D029721:Drosophila Proteins; D034481:Heterogeneous-Nuclear Ribonucleoprotein Group A-B; D034441:Heterogeneous-Nuclear Ribonucleoproteins; D018398:Homeodomain Proteins; C487427:Hrb27C protein, Drosophila; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D015534:Trans-Activators; D014157:Transcription Factors; D016211:Transforming Growth Factor alpha; C066177:Ubx protein, Drosophila; C056478:bcd protein, Drosophila; C083730:grk protein, Drosophila; C091675:osk protein, Drosophila; C069927:stau protein, Drosophila