Selective Translational Regulation of Male Fertility

说明（由申请人提供）：在哺乳动物中，精子发生的进程受到时间和空间特异性翻译调控。但目前还不知道特定的转录本是如何选择的，也不知道它们是如何与翻译效应物相互作用的。该项目以新的遗传资源弥补了这一差距。我们以前的工作表明，一个真核翻译起始因子，EIF 4G 3，是需要在精子发生和男性生育的细胞周期进程。令人惊讶的是，EIF 4G 3表现出高水平的翻译选择性;一个特异性EIF 4G 3底物，Hspa 2 mRNA，编码热休克伴侣蛋白HSPA 2，是一个“报告”转录本的选择性机制的研究。Eif 4g 3突变小鼠的雄性不育表型为精子发生中翻译选择性的至关重要性提供了令人信服的证据。遗传模型提供了宝贵的资源，描绘的翻译调控的特异性实现的机制。该项目的实验方法将解决报告转录本（Hspa 2）和效应蛋白EIF 4G 3，调节其在精子发生中的翻译命运的作用。目的1将研究的mRNA底物，是通过使用遗传模型和蛋白质相互作用的方法来确定转录本序列的功能和RNA结合蛋白（RBP），是至关重要的EIF 4G 3的翻译激活进行选择性翻译。目的2将调查的翻译特异性，EIF 4G 3，通过使用新的遗传模型和细胞生物学分析，以确定域的功能，使其能够在精子发生过程中的细胞周期进程的背景下，调节翻译的调节。目的3将通过使用遗传资源来鉴定受EIF 4G 3类似的翻译调节的其他底物，来解决精子发生中特异性机制的程度。总之，这些目标将定义网络的球员和解决机制，强制执行显着的翻译选择性，所以至关重要的是成功的精子发生。!

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. !