Localization-dependent oskar protein accumulation; control after the initiation of translation.
The appearance of Oskar protein occurs coincident with localization of oskar mRNA to the posterior pole of the Drosophila oocyte, and earlier accumulation of the protein is prevented by translational repression. We find that the nascent polypeptide-associated complex (NAC) is required for correct localization of oskar mRNA. The timing of the defects suggests that, if NAC acts directly via an interaction with nascent Oskar protein, oskar mRNA should be undergoing translation prior to its localization. Polysome analysis confirms that oskar mRNA is associated with polysomes even in the absence of localization of the mRNA or accumulation of Oskar protein. Thus, the mechanisms that prevent accumulation of Oskar protein until it can be secured at the posterior pole of the oocyte include regulated degradation or inhibition of translational elongation.
Braat
Arie Koen
AK
Institute for Cellular and Molecular Biology, Section of Molecular Cell and Developmental Biology, The University of Texas at Austin, Austin, TX 78712, USA.
Yan
Nan
N
Arn
Eric
E
Harrison
Dianne
D
Macdonald
Paul M
PM
D000818:Animals; D016764:Cell Polarity / Q000235:genetics; D004330:Drosophila / Q000166:cytology / Q000254:growth & development* / Q000378:metabolism; D029721:Drosophila Proteins / Q000096:biosynthesis* / Q000235:genetics*; D039642:Eukaryotic Initiation Factors / Q000235:genetics / Q000378:metabolism*; D005260:Female; D018832:Molecular Chaperones; D009865:Oocytes / Q000166:cytology / Q000254:growth & development* / Q000378:metabolism; D009866:Oogenesis / Q000235:genetics*; D011132:Polyribosomes / Q000235:genetics / Q000378:metabolism; D014176:Protein Biosynthesis / Q000235:genetics*; D021381:Protein Transport / Q000235:genetics; D012333:RNA, Messenger / Q000378:metabolism; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism*
D029721:Drosophila Proteins; D039642:Eukaryotic Initiation Factors; D018832:Molecular Chaperones; D012333:RNA, Messenger; D015534:Trans-Activators; C096099:nascent-polypeptide-associated complex; C091675:osk protein, Drosophila