Signaling pathways that mediate mammalian oocyte cortical mechanics

介导哺乳动物卵母细胞皮质力学的信号通路

• 批准号: 8583163
• 负责人: JANICE P EVANS
• 金额: $ 8.1万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-07-15 至 2015-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8583163
• 关键词: 14-3-3 Proteins; Actins; Actomyosin; Address; Biochemical; Biological; Biological Models; Biological Process; Biophysics; Cell Shape; Cell division; Cell physiology; Cells; Cellular Morphology; Characteristics; Competence; Complement; Cytokinesis; Cytoskeleton; Data; Defect; Dictyostelium; Dominant-Negative Mutation; Elements; Embryo; Embryonic Development; Family member; Female; Female infertility; Fertility; Fertilization; Foundations; Future; GTPase-Activating Proteins; Genetic Screening; Germ Cells; Goals; Guanosine Triphosphate Phosphohydrolases; Link; Liquid substance; Mechanics; Mediating; Meiosis; Membrane; Metaphase; Methodology; Methods; Microinjections; Mitosis; Mitotic; Modeling; Molecular; Monomeric GTP-Binding Proteins; Motor; Mus; Myosin Type II; Oocytes; Ovulation; Peptides; Phenotype; Positioning Attribute; Process; Property; Proteins; Publishing; RNA Interference; Recording of previous events; Regulation; Regulation of Cell Shape; Research; Research Personnel; Series; Signal Pathway; Signal Transduction; Signaling Molecule; Staging; System; Testing; Work; base; cell type; egg; ezrin; insight; moesin; non-muscle myosin; novel; oocyte maturation; p21 activated kinase; protein crosslink; public health relevance; radixin protein; research study; segregation; zygote

DESCRIPTION (provided by applicant): Successful embryonic development is dependent on the female gamete progressing correctly through its meiotic divisions, with the first division occurring during oocyte maturation and the second completing upon fertilization. Defects in these processes during meiosis I or II can compromise egg quality and competence to form a healthy embryo, thus negatively impacting female fertility. The fundamental biological question addressed in this proposal is how does the oocyte undergo the necessary asymmetric cell divisions during meiotic cytokinesis to create the egg and the polar bodies? The answer to this fundamental question is not as simple as might be assumed. From a cellular mechanics standpoint, it is remarkable that this cell division occurs at all, as fluid dynamics would predict that the polar body would simply collapse into the oocyte. Our work has identified a novel and previously unappreciated contributor to successful mammalian female meiosis - cortical tension in the oocyte, including demonstration that abnormal cortical tension is linked with aberrant spindle function and cytokinesis during completion of meiosis (Mol. Biol. Cell 21, 3182- 3192). We also identified some of the molecular basis of oocyte mechanics, as we demonstrated that oocyte tension is altered upon perturbation of actin, the actin-associated motor protein nonmuscle myosin-II, and the actin-to-membrane crosslinking proteins known as ERMs (for the family members ezrin, radixin, and moesin). To expand on this published work on the structural components involved in mammalian oocyte mechanics, this project seeks to analyze the functions of key proteins in cellular mechanics and cell shape regulation during progression of the mammalian oocyte through meiosis and cytokinesis. Specifically, we seek to characterize the system that regulates and fine-tunes actomyosin-mediated contractility in the oocyte cortical cytoskeleton. Aim 1 is a brief series of studies that will be used to refine methodologies for this work. Aim 2 is the substantial work of this proposal, testing the specific hypothesis that a signaling module composed of the small GTPase Rac1, 14-3-3, p21-activated kinase, and IQ-motif and GTPase-containing protein regulates the oocyte's structural cytoskeletal elements to modulate the oocyte's mechanical properties. We have preliminary data that provide the foundation for this hypothesis, and now seek to discover the contribution of these molecules and this signaling network to cortical tension in mouse oocytes. The overarching goal of this R03 project is to identify the molecules and signaling pathways that modulate mammalian oocyte mechanics, to build a conceptual framework that will be the foundation for future more detailed studies. This project will extend understanding of the female gamete in a completely new direction - bringing insights from cellular mechanics into our view of the oocyte-to-egg and egg-to-embryo transitions.

描述（由申请人提供）：成功的胚胎发育取决于雌性配子通过其减数分裂正确进行，第一次分裂发生在卵母细胞成熟期间，第二次分裂在受精后完成。减数分裂I或II期间这些过程中的缺陷会损害卵子质量和形成健康胚胎的能力，从而对女性生育力产生负面影响。在这个提议中提出的基本生物学问题是卵母细胞如何在减数分裂胞质分裂过程中进行必要的不对称细胞分裂以产生卵子和极体？这个基本问题的答案并不像人们想象的那么简单。从细胞力学的观点来看，这种细胞分裂的发生是值得注意的，正如流体动力学所预测的那样 极体会简单地坍塌成卵母细胞。我们的工作已经确定了一种新的和以前未被认识到的成功的哺乳动物雌性减数分裂的贡献者-卵母细胞中的皮质张力，包括证明异常的皮质张力与减数分裂完成期间异常的纺锤体功能和胞质分裂有关（Mol. Cell 21，3182- 3192）。我们还确定了卵母细胞力学的一些分子基础，因为我们证明了卵母细胞张力在肌动蛋白、肌动蛋白相关运动蛋白非肌肉肌球蛋白II和肌动蛋白-膜交联蛋白（称为ERM）（家族成员埃兹蛋白、根蛋白和膜突蛋白）扰动后发生改变。为了扩展哺乳动物卵母细胞力学中所涉及的结构组件的已发表工作，该项目旨在分析哺乳动物卵母细胞通过减数分裂和胞质分裂的进展过程中细胞力学和细胞形状调节中的关键蛋白质的功能。具体来说，我们试图表征系统，调节和微调肌动球蛋白介导的收缩性的卵母细胞皮质细胞骨架。目标1是一个简短的系列研究，将用于完善这方面的方法 工作目的2是该建议的实质性工作，测试特定的假设，即由小的GTTR Rac 1，14-3-3，p21激活的激酶，和IQ基序和GTP酶的蛋白质组成的信号模块调节卵母细胞的结构细胞骨架元素，以调节卵母细胞的机械性能。我们有初步的数据，为这一假设提供了基础，现在试图发现这些分子和这个信号网络的贡献，在小鼠卵母细胞皮质张力。这个R 03项目的总体目标是确定调节哺乳动物卵母细胞力学的分子和信号通路，以建立一个概念框架，这将是未来更详细研究的基础。该项目将以一个全新的方向扩展对雌性配子的理解-将细胞力学的见解带入我们对卵母细胞到卵子和卵子到胚胎过渡的看法。