CAREER: Protein degradation during the maternal-to-zygotic transition

对于所有的生命形式来说，发育都是一个高度同步和基本的过程。动物发育的最初阶段是由生物分子指导的，这些生物分子是由母亲制造的，并沉积到正在发育的卵子中。一旦它们发挥了作用，这些母体生物分子就必须被移除，取而代之的是胚胎制造的新分子。这个过程被称为母体到受精卵的转变，对于动物胚胎的发生是必不可少的。尽管母体到受精卵的转变很重要，但很少有人关注了解母体蛋白质是如何被去除的。这一职业奖的目标是通过结合遗传和分子生物学技术来填补这一空白。这项研究将为了解三个鲜为人知但关键的问题提供切入点：1)胚胎如何针对母体蛋白质进行降解；2)蛋白质降解在发育过程中是如何控制的；以及3)当这一过程出错时，发育后果是什么？这项奖励还将为那些被认为代表少数族裔的本科生提供15个月的带薪实习机会，并在当地的本科生机构--丹佛大都会州立大学(Metro)学习。有意义的研究经验，如该奖项提供的经验，将把学生带入科学成功的轨道。因此，这个奖项将描绘出推动胚胎发生的蛋白质去除的巨大范围，将改变丹佛的教育生态系统，并最终将有助于增加科学的多样性。在果蝇体内，一种被称为“近藤玛丽”的E2泛素结合酶去除了几种对卵子发生至关重要但胚胎并不需要的母体蛋白质。近藤玛丽研究的是一种名为CTLH复合体的E3泛素连接酶。然而，近藤玛丽和CTLH复合体是如何控制的，人们知之甚少。利用遗传学和分子生物学的结合，该项目将研究近藤玛丽及其合作伙伴CTLH复合体对底物特异性和酶活性的严格时间控制的机制，并确定错误的活动时机对发育的影响。最后，作为教育计划的一部分，将使用基于RNAi的筛查来识别果蝇胚胎发生所必需的其他E2和E3，这将为未来在母体到受精卵转变过程中母体蛋白质去除的研究奠定基础。总而言之，这些研究将揭示发育生物学的一个新领域--蛋白质衰变--这对从单细胞胚胎创造成年动物至关重要。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

For all life forms, development is a highly synchronized and fundamental process. The initial stages of animal development are directed by biomolecules that were made by the mother and deposited into the growing egg. Once they have served their role, these maternal biomolecules must be removed and replaced with new ones made by the embryo. This process, known as the maternal-to-zygotic transition, is essential for animal embryogenesis. Despite the importance of the maternal-to-zygotic transition, little attention has been placed on understanding how maternal proteins are removed. The goal of this CAREER award is to fill this gap through a combination of genetic and molecular biology techniques. This research will provide an entry point into three poorly understood, but critical, questions: 1) how do embryos target maternal proteins for degradation; 2) how is protein degradation controlled during development; and 3) what are the developmental consequences when this process goes awry? This award will also provide 15-month paid internships to undergraduates who identify as underrepresented minorities and study at a local undergraduate institution, Metropolitan State University of Denver (Metro). Meaningful research experiences, like the ones provided by this award, will set the students on a trajectory of success in science. This award will thus map the enormous scope of protein removal in driving embryogenesis, will transform the educational ecosystem in Denver, and ultimately will help to increase diversity in science. In Drosophila melanogaster, an E2 ubiquitin-conjugating enzyme known as “Marie Kondo” removes several maternal proteins that were critical for oogenesis but are not needed by the embryo. Marie Kondo works with an E3 ubiquitin ligase called the CTLH complex. However, little is known about how Marie Kondo and the CTLH complex are controlled. Using a combination of genetics and molecular biology, this project will investigate the mechanisms underlying the tight temporal control of substrate specificities and enzymatic activities of Marie Kondo and its partner, the CTLH complex, and determine the developmental consequences of mistiming their activity. Finally, as part of the educational program, an RNAi-based screen will be used to identify other E2s and E3s essential for the Drosophila embryogenesis, which will set the stage for future investigations in maternal protein removal during the maternal-to-zygotic transition. Together, these investigations will shed light on a new area of developmental biology—protein decay—that is critical for the creation of an adult animal from a single-cell embryo.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.