The Drosophila hnRNPA/B homolog, Hrp48, is specifically required for a distinct step in osk mRNA localization.
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.
Huynh
Jean-René
JR
The Wellcome Trust/Cancer Research UK, Gurdon Institute and Department of Genetics, Cambridge University, Tennis Court Road, Cambridge CB2 1QR, United Kingdom.
Munro
Trent P
TP
Smith-Litière
Katia
K
Lepesant
Jean-Antoine
JA
St Johnston
Daniel
D
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
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