P granules and control of germ cells development

摘要 生殖细胞执行多细胞生物体的生殖功能，而正常生殖细胞 发展确保了物种的生存。胚芽颗粒是胚芽中保守的细胞质细胞器 细胞，对这些细胞的生存、分化和功能是必不可少的。胚芽颗粒中的突变 在模式生物中，成分或其表达缺失会导致不孕，并与模型生物中的不孕有关 人类。相比之下，体细胞中生殖粒成分的不适当表达与 人类的致癌作用。发现了许多rna结合蛋白和发育调节的mRNAs。 丰富的胚芽颗粒，导致假设这些细胞器在调节mrna的功能。 稳定性或翻译活性；然而，这些细胞器的分子功能仍未确定。 线虫线虫有助于理解生殖系的翻译调控 发展。我们以前的研究证实了线虫胚芽颗粒的特异性贡献(P 颗粒)对生殖系干细胞中RNA结合调节蛋白FBF-2的调节作用，但 关于这一贡献的机制基础，还有很多需要了解。我们的实验系统是 准备在分子细节上解决这个问题。我们的研究将集中在FBF-2作为一种细菌范例 颗粒对生殖系中RNA结合蛋白活性的调节作用。通过整合生物化学， 基于分子、遗传和成像的方法，我们将：1)定义FBF-2的特定组件 调控复合体；2)确定依赖于P颗粒完整性的FBF-2的辅助因子 FBF-2；3)确定FBF-2介导P颗粒募集和FBF-2特异性调控的序列 活动。这些研究将揭示细菌颗粒依赖调节的一般机制。因为细菌 颗粒是保守的细胞器，FBF-2是保守的PUF蛋白家族的成员，本文对此进行了研究 模型系统将为人类不孕不育的原因提供关键的见解。

Abstract Germ cells carry out the reproductive function of the multicellular organisms, and normal germ cell development ensures survival of the species. Germ granules are conserved cytoplasmic organells of the germ cells, essential for the survival, differentiation, and function of these cells. Mutations in germ granule components or loss of their expression lead to infertility in model organisms and are associated with infertility in humans. By contrast, inappropriate expression of germ granule components in somatic cells is linked to carcinogenesis in humans. Many RNA-binding proteins and developmentally regulated mRNAs are found enriched in the germ granules, leading to a hypothesis that these organelles function in regulation of mRNA stability or translational activity; yet, the molecular function of these organelles is still undefined. The nematode C. elegans has been instrumental for understanding translational regulation of germline development. Our previous studies demonstrated specific contribution of C. elegans germ granules (P granules) to the regulation exerted by an RNA-binding regulatory protein FBF-2 in germline stem cells, yet much remains to be learned about the mechanistic basics of this contribution. Our experimental system is poised to address this question in molecular detail. Our studies will focus on FBF-2 as a paradigm of germ granule contribution to regulating the activity of RNA-binding proteins in germline. By integrating biochemical, molecular, genetic, and imaging-based approaches, we will: 1) Define the specific components of the FBF-2 regulatory complex; 2) Identify the cofactors of FBF-2 that depend on P granule integrity for their assembly with FBF-2; 3) Determine the sequences of FBF-2 mediating P granule recruitment and FBF-2-specific regulatory activity. These studies will reveal general mechanisms of germ granule-dependent regulation. Since the germ granules are conserved organelles and FBF-2 is a member of conserved PUF protein family, studies in this model system will provide critical insight into the causes of infertility in humans.