Precise Temporal Regulation of Post-transcriptional Repressors Is Required for an Orderly Drosophila Maternal-to-Zygotic Transition
Precise Temporal Regulation of Post-transcriptional Repressors Is Required for an Orderly Drosophila Maternal-to-Zygotic Transition
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DOI：
10.1016/j.celrep.2020.107783
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发表时间：
2020-06-23
期刊：
影响因子：
8.8
通讯作者：
Lipshitz, Howard D.
中科院分区：
文献类型：
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作者：
Cao, Wen Xi;Kabelitz, Sarah;Lipshitz, Howard D.
在动物胚胎中，母合子转换（MZT）将发育控制权从母体基因产物转移到合子基因产物。我们发现，母体蛋白质组代表了果蝇基因组蛋白质编码能力的一半以上，并且在MZT期间，该蛋白质组的2%迅速降解。清除的蛋白质包括转录后阻遏物Cup、Trailer hitch（TRAL）、31 B处的母体表达（ME 31 B）和Smaug（SMG）。尽管泛素-蛋白酶体系统对于清除这些阻遏物是必需的，但不同的E3连接酶复合物靶向它们：Lis 1同源性（CTLH）复合物的C末端靶向Cup、TRAL和ME 31 B，用于在MZT的早期降解，而Skp/Cullin/Fbox复合物（SCF）靶向MZT末端的SMG。删除SMG的C-末端233个氨基酸消除了F-box蛋白相互作用，并赋予对降解的免疫力。持续性SMG下调其母体贡献被SMG降解的mRNA的合子再表达。因此，SMG的清除允许有序的MZT。
In animal embryos, the matemal-to-zygotic transition (MZT) hands developmental control from maternal to zygotic gene products. We show that the maternal proteome represents more than half of the protein-coding capacity of Drosophila melanogaster's genome, and that 2% of this proteome is rapidly degraded during the MZT. Cleared proteins include the post-transcriptional repressors Cup, Trailer hitch (TRAL), Maternal expression at 31B (ME31B), and Smaug (SMG). Although the ubiquitin-proteasome system is necessary for clearance of these repressors, distinct E3 ligase complexes target them: the C-terminal to Lis1 Homology (CTLH) complex targets Cup, TRAL, and ME31B for degradation early in the MZT and the Skp/Cullin/Fbox-containing (SCF) complex targets SMG at the end of the MZT. Deleting the C-terminal 233 amino acids of SMG abrogates F-box protein interaction and confers immunity to degradation. Persistent SMG downregulates zygotic re-expression of mRNAs whose maternal contribution is degraded by SMG. Thus, clearance of SMG permits an orderly MZT.