Selective Translational Regulation of Male Fertility

描述(申请人提供)：在哺乳动物中，精子发生的过程受制于时间和空间上特定的翻译调控。但目前还不知道具体的文本是如何选择的，或者它们是如何与翻译的效应者相互作用的。该项目用新的遗传资源弥合了这一差距。我们以前的工作表明，真核翻译起始因子EIF4G3在精子发生和男性生育的细胞周期进程中是必需的。令人惊讶的是，EIF4G3表现出高水平的翻译选择性；一个特定的EIF4G3底物，Hspa2 mRNA，编码热休克伴侣蛋白HSPA2，是这一选择性机制研究的“报告”转录本。Eif4g3突变小鼠的雄性不育表型为翻译选择性在精子发生中的关键重要性提供了令人信服的证据。该遗传模型为描述实现翻译调控特异性的机制提供了宝贵的资源。该项目的实验方法将解决报告转录本(Hspa2)和效应蛋白EIF4G3的作用，EIF4G3调节其在精子发生中的翻译命运。目的1将通过使用遗传模型和蛋白质相互作用的方法来研究选择性翻译的mRNA底物，以确定转录序列特征和对EIF4G3翻译激活至关重要的RNA结合蛋白(RBPs)。目的2将通过使用新的遗传模型和细胞生物学分析来研究翻译特异性的调节因子EIF4G3，以确定使其能够在精子发生过程中的细胞周期进展中调节翻译的结构域特征。目标3将通过使用遗传资源来确定受EIF4G3类似翻译调控的其他底物，从而解决精子发生中特异性机制的程度。总而言之，这些目标将定义参与者网络并解决机制，这些机制强制执行对成功的精子发生至关重要的显著翻译选择性。好了！

DESCRIPTION (provided by applicant): In mammals, the progress of spermatogenesis is subject to temporally and spatially specific translational regulation. But it is not known how specific transcripts are chosen or how they interact with effectors of translation. This project bridges the gap with new genetic resources. Our previous work demonstrated that a eukaryotic translation initiation factor, EIF4G3, is required for cell cycle progression in spermatogenesis and male fertility. Surprisingly, EIF4G3 exhibits a high level of translational selectivity; a specfic EIF4G3 substrate, the Hspa2 mRNA, encoding the heat shock chaperone protein HSPA2, is a "reporter" transcript for this study of selectivity mechanisms. The male infertility phenotype of Eif4g3 mutant mice provides compelling evidence for the crucial importance of translational selectivity in spermatogenesis. The genetic model provides invaluable resources to delineate mechanisms by which specificity of translational regulation is achieved. Experimental approaches of this project will address the roles of both the reporter transcript (Hspa2) and the effector protein, EIF4G3, that regulates its translational fate in spermatogenesis. Aim 1 will investigate the mRNA substrate that is subject to selective translation by using genetic models and protein interaction methods to determine both transcript sequence features and the RNA binding proteins (RBPs) that are crucial for its translational activation by EIF4G3. Aim 2 will investigate the regulator of translational specificity, EIF4G3, by using new genetic models and cell biological analyses to determine the domain features that allow it to regulate translation in the context of cell cycle progress during spermatogenesis. Aim 3 will address the extent of the specificity mechanism in spermatogenesis by using genetic resources to identify other substrates subject to similar translational regulation by EIF4G3. Together, these aims will define the network of players and resolve mechanisms that enforce the remarkable translational selectivity so crucially required for successful spermatogenesis. !