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

基本信息

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
项目类别：
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

项目摘要

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配子通过减数分裂的正确进展，第一次分裂发生在卵母细胞成熟期间，第二次分裂在受精时完成。减数分裂 I 或 II 期间这些过程的缺陷可能会损害卵子质量和形成健康胚胎的能力，从而对女性生育能力产生负面影响。该提案解决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经历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想象的那么简单。从细胞力学的角度来看，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塌陷到卵母细胞中。我们的工作发现了哺乳动物雌性减数分裂成功的一个新的且以前未被认识的因素 - 卵母细胞中的皮质张力，包括证明异常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. Biol. Cell 21, 3182-第3192章）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 和肌动蛋白与膜交联蛋白（称为 ERM）的扰动下发生改变。家族成员 ezrin、radixin 和 moesin）。为了扩展已发表的有关哺乳动物卵母细胞力学结构成分的研究成果，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过程中细胞力学和细胞形状调节中关键蛋白质的功能。具体来说，我们试图表征调节和微调卵母细胞皮质细胞骨架中肌动球蛋白介导的收缩性的系统。目标 1 是一系列简短的研究，将用于完善该目标的方法工作。目标 2 是该提案的实质性工作，测试由小 GTPase Rac1、14-3-3、p21 激活激酶以及 IQ 基序和含有 GTPase 的蛋白质组成的信号模块调节卵母细胞的结构细胞骨架的具体假设调节卵母细胞机械特性的元素。我们拥有为这一假设提供基础的初步数据，现在寻求发现这些分子和信号网络对小鼠卵母细胞皮质张力的贡献。 R03 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，建立一个概念框架，为未来更详细的研究奠定基础。该项目将以全新的方向扩展对雌配子的理解——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转变的看法。