Producing, provisioning, and protecting the egg: Regulation of DNA replication, mRNA translation, and proteolysis for the transition from oocyte to embryo

卵子的生产、供应和保护：从卵母细胞到胚胎过渡的 DNA 复制、mRNA 翻译和蛋白水解的调节

• 批准号: 9071147
• 负责人: Terry L. ORR-WEAVER
• 金额: $ 61.98万
• 依托单位: WHITEHEAD INSTITUTE FOR BIOMEDICAL RES
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-04-04 至 2021-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9071147
• 关键词: Affect; Binding; Cell Cycle; Complex; Congenital Abnormality; DNA biosynthesis; Defect; Development; Drosophila genus; Embryo; Excision; Fertility; Gene Dosage; Genetic; Genetic Transcription; Genetic Translation; Goals; Health; Human; Infertility; Light; Link; Maps; Meiosis; Messenger RNA; Mitosis; Modeling; Modification; Oocytes; Osmolalities; Osmolar Concentration; Oxidation-Reduction; Pathway interactions; Phosphotransferases; Process; Proteins; Proteolysis; Proteome; Proteomics; Regulation; Replication Initiation; Replication Origin; Repression; Research; Role; Signal Transduction; Testing; Tissues; Totipotent; Translations; Ubiquitin; Work; anaphase-promoting complex; cancer cell; egg; glycine transporter; insight; origin recognition complex; prevent; programs; protein degradation; public health relevance; response

 DESCRIPTION (provided by applicant): The goal of this research program is to define how an egg is produced, provisioned, and protected and how the egg is dramatically reorganized for the transition from oocyte to embryo. Analysis of this key window in development is accessible in Drosophila, and due to the conservation of regulators in development, studies in Drosophila will identify regulatory mechanisms and components that will shed light on fundamental features of early development, with implications for human health in understanding developmental defects and infertility. In addition, analysis of how a Drosophila egg is produced has provided models for the control of metazoan DNA replication, generating insights into how gene copy number can become altered in cancer cells. The proposed research will study the crucial processes of DNA replication, mRNA translation, and proteolysis, all of which are subjected to developmental control in the transition from oocyte to embryo. The regulation of replication origins has remained elusive in metazoans because it has not been possible to determine what defines an origin, to localize the essential Origin Recognition Complex (ORC), or to capture origin firing and its control. Drosophila offers the tremendous advantages of developmental control of origin activity and the ability to localize ORC in differentiated tissues to map origins The effect of differentiation and cell cycle modification on ORC localization will be determined, and the relationship between ORC binding, transcription and developmental repression of replication defined. Replication origins that bind ORC across a broad zone and undergo repeated rounds of origin firing in response to differentiation signals will be exploited to deciphr how replication initiation is controlled. The transition from the differentiated oocyte to the totipotent embryo occurs in the absence of transcription, involving rapid changes in osmolarity and extensive remodeling of the proteome by dramatic changes in mRNA translation and proteolysis. Regulators identified by genetic and proteomic screens indicate a crucial role for redox state and a glycine transporter in egg activation that will be delineated. The PNG kinase was shown to be a master regulator of mRNA translation specifically at this developmental transition, providing the link between completion of meiosis and control of mRNA translation in the egg. The mechanism(s) through which PNG activates translation will be explored by testing the hypotheses that it phosphorylates and inactivates translational repressors and affects the localization of mRNAs to RNP complexes in the egg. A unique form of the Anaphase Promoting Complex (APC), APCCort, specifically targets proteins for degradation whose removal is required for the change from meiosis to mitosis. The requirement for APCCort-targeted degradation of recently identified substrates that are critical in the oocyte-to-embryo transition will be evaluated, and the function of other components of the ubiquitin pathway expressed specifically in this developmental period will be defined.

 描述（由适用提供）：该研究计划的目的是定义如何产生，配置和保护卵，以及如何重新整理鸡蛋从卵母细胞到胚胎的过渡。在果蝇中可以分析这种开发中的关键窗口，并且由于监管机构在开发中的保存，果蝇的研究将确定调节机制和组件，这些机制和组件将揭示早期发展的基本特征，对人类健康在理解发展缺陷和不匹配方面的影响。此外，分析如何产生果蝇卵，为控制后DNA复制提供了模型，从而对癌细胞中基因拷贝数的改变产生了见解。拟议的研究将研究DNA复制，mRNA翻译和蛋白水解的关键过程，所有这些过程均在从卵母细胞到胚胎的过渡中受到发育控制。复制起源的调节在后生动物中仍然难以捉摸，因为不可能确定什么定义来源，定位基本的起源识别复合物（ORC），或捕获原点发射及其控制。将确定果蝇在分化组织中定位ORC绘制ORC绘制分化和细胞周期修饰对ORC定位的影响的能力，并确定果蝇的巨大优势，并确定ORC结合，转录，转录，转录和发展的复制代表性之间的关系。将ORC跨越宽区域结合并经过反应响应分化信号的重复发射的复制起源将被利用如何控制复制计划。在没有转录的情况下，从分化的卵母细胞到全能胚胎的过渡发生，涉及渗透压的快速变化和通过mRNA翻译和蛋白水解的急剧变化而对蛋白质组进行广泛的重塑。通过遗传和蛋白质组学筛选确定的调节剂表明氧化还原状态和甘氨酸转运蛋白在卵子激活中的至关重要作用。 PNG激酶被证明是在这种发育过渡时特别是mRNA翻译的主要调节剂，提供了减数分裂的完成与卵中mRNA翻译的控制之间的联系。通过测试它磷酸化并灭活翻译反射器并影响mRNA对卵中RNP复合物的定位的假设，将探索PNG激活翻译的机制。 APCCORT的一种独特形式促进复合物（APC），特别是针对降解的蛋白质，其去除是从减数分裂变为有丝分裂所必需的。将评估在卵母细胞到胚胎过渡中至关重要的最近确定的底物的APCCORT靶向降解的要求，将评估在此发育期间特异性表达的泛素途径的其他组件的功能。