The translationally regulated msl-2 mRNP from Drosophila

来自果蝇的翻译调节 msl-2 mRNP

• 批准号: 5311492
• 负责人: Professor Dr. Matthias Hentze
• 金额: --
• 依托单位: Europäisches Laboratorium für Molekularbiologie (EMBL)
• 依托单位国家: 德国
• 项目类别: Research Units
• 财政年份: 2001
• 资助国家: 德国
• 起止时间: 2000-12-31 至 2007-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/5311492?language=en
• 关键词: translationally; regulated; msl; mRNP; Drosophila

Dosage compensation in Drosophila melanogaster requires the male-specific expression of the MSL (male-specific lethal) complex. The male-specific expression of the MSL-2 subunit of this complex represents the key difference in the dosage compensation pathway. MSL-2 protein expression is inhibited posttranscriptionally in females by the female-specific RNA binding protein Sex-Lethal (SXL), which inhibits ms1-2 expression by an integrated two step mechanism via SXL binding sites in both the 5' UTR and the 3' UTR of the ms1-2 pre mRNA. SXL binding to the 5' UTR sites enforces the retention of the intron which is removed in male flies. Following export of this mRNA into the cytoplasm, SXL bound to these retained 5' UTR sites synergizes with additional SXL bound to the 3' UTR sites to establish a translational repressed ms1-2 mRNA-protein complex (mRNP). We have recapitulated the translational regulation in a cell-free system from Drosophila embryos using in vitro transcribed mRNAs and recombinant SXL protein. We propose to dissect the silenced mRNP by biochemical analysis of functionally important cis-acting elements, the functional domains of the trans-acting factor SXL and the identification of co-factors.

黑腹果蝇中的剂量补偿需要雄性特异性表达 MSL（雄性特异性致死）复合物。该复合物的 MSL-2 亚基的男性特异性表达代表了剂量补偿途径的关键差异。 MSL-2 蛋白表达在雌性中受到雌性特异性 RNA 结合蛋白 Sex-Lethal (SXL) 的转录后抑制，该蛋白通过 ms1-2 前体 mRNA 5' UTR 和 3' UTR 中的 SXL 结合位点，通过集成的两步机制抑制 ms1-2 表达。 SXL 与 5' UTR 位点的结合强制保留了在雄性果蝇中被移除的内含子。将该 mRNA 输出到细胞质后，与这些保留的 5' UTR 位点结合的 SXL 与与 3' UTR 位点结合的其他 SXL 协同作用，建立翻译抑制的 ms1-2 mRNA-蛋白质复合物 (mRNP)。我们使用体外转录的 mRNA 和重组 SXL 蛋白概括了果蝇胚胎无细胞系统中的翻译调控。我们建议通过功能重要的顺式作用元件的生化分析、反式作用因子SXL的功能域以及辅因子的鉴定来剖析沉默的mRNP。