Molecular Mechanism of the Contractile-Ring Assembly in Fission Yeast Cytokinesis

裂殖酵母细胞分裂中收缩环组装的分子机制

• 批准号: 8042529
• 负责人: Jian-Qiu Wu
• 金额: $ 27.93万
• 依托单位: OHIO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-04-01 至 2014-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8042529
• 关键词: Actinin; Actins; Actomyosin; Animals; Apoptotic; Binding; Biochemical; Biological Models; Bundling; Cell Differentiation process; Cell Proliferation; Cell division; Cell physiology; Cells; Characteristics; Complex; Confocal Microscopy; Contractile System; Cytokinesis; Data; Dependency; Drosophila polo protein; Epithelial; Erythrocytes; Evolution; Fimbrin; Fission Yeast; Fluorescence Recovery After Photobleaching; Fluorescence Resonance Energy Transfer; Foundations; Generations; Genetic; Genome; Goals; Human; Learning; Link; Malignant Neoplasms; Maps; Measures; Microfilaments; Microscopic; Molecular; Motor; Muscle; Myosin Regulatory Light Chains; Myosin Type II; Organism; Pathway interactions; Phosphorylation; Physical condensation; Play; Positioning Attribute; Process; Proteins; Reproduction; Research; Resolution; Role; Signal Pathway; Signal Transduction; Signaling Protein; Simulate; Site; Solid; Somatic Cell; Stem cells; Structural Protein; Structure; Systems Analysis; Testing; Work; Wound Healing; Yeasts; anillin; base; cancer cell; cell type; constriction; crosslink; daughter cell; fungus; human disease; link protein; mutant; protein structure; public health relevance; research study; simulation

DESCRIPTION (provided by applicant): A significant gap exists in understanding the mechanism of contractile-ring assembly during cytokinesis, which partitions cellular constituents into two new daughter cells and plays a crucial role in cell reproduction and cell differentiation. The long-term goal of our research is to investigate cytokinesis in yeast, in normal somatic and stem cells, as well as in cancer cells. The objective of this application is to investigate the molecular mechanism of the assembly of the contractile ring in fission yeast cytokinesis. The fission yeast Schizosaccharomyces pombe has emerged as one of the leading model systems for the analysis of cytokinesis. Not only is it genetically tractable and favorable for microscopic analysis, but it also has the smallest fully sequenced eukaryotic genome and carries out cytokinesis much like animal cells. Contractile rings consisting of actin filaments, myosin-II motors, and >30 other proteins are essential for cytokinesis in both yeast and animal cells, including humans. The majority of these proteins are conserved during evolution. The central hypothesis of this proposal is that the cytokinetic contractile ring assembles progressively at the cleavage site from a broad band of precursor nodes into a complex protein structure. Actin cross-linking proteins and Polo kinase play essential structural and signaling roles during the assembly. Based on a solid foundation of background research and strong preliminary data, this hypothesis will be tested by investigating three specific aims: 1) Elucidate the roles of the anillin Mid1p in node formation and identify its binding partners in the nodes; 2) Establish the roles of actin cross-linking proteins Fimbrin and 1-actinin in coalescing the nodes into the contractile ring; 3) Explore the signaling pathways that trigger node formation and node condensation into the contractile ring. A combination of cellular, genetic, biochemical, and confocal microscopic approaches will be employed in these studies. This research is significant because it will reveal how proteins work together during contractile-ring assembly in cytokinesis, and how the anillin Mid1p initiates the assembly of the contractile ring by interacting with evolutionarily conserved structural and signaling proteins. Discerning the assembly of the essential contractile-ring is an important step towards understanding cytokinesis. Additionally, it will help us understand complex actomyosin contractile systems in other cellular processes. PUBLIC HEALTH RELEVANCE: Uncontrolled and misoriented cell divisions are defining characteristics of cancer. Contractile rings, tiny muscle-like force-producing structures, are the common machinery for cytokinesis and other processes including erythrocyte enucleation, morphogenetic epithelial closure, epithelial wound healing, and apoptotic cell extrusion. Thus, much of what we learned about the evolutionarily conserved proteins in cytokinesis is ultimately relevant and applicable to cancer and other human diseases.

描述（由申请人提供）：在胞质分裂期间，在理解收缩环组装的机制方面存在重大差距，该机制将细胞组分分成两个新的子细胞，并在细胞繁殖和细胞分化中起关键作用。我们研究的长期目标是研究酵母、正常体细胞和干细胞以及癌细胞中的胞质分裂。本申请的目的是研究裂殖酵母胞质分裂收缩环组装的分子机制。裂殖酵母粟酒裂殖酵母已成为胞质分裂分析的主要模型系统之一。它不仅在遗传上易于处理，有利于显微镜分析，而且它还具有最小的完全测序的真核基因组，并像动物细胞一样进行胞质分裂。由肌动蛋白丝、肌球蛋白II马达和>30种其他蛋白质组成的收缩环对于酵母和动物细胞（包括人类）的胞质分裂是必需的。这些蛋白质中的大多数在进化过程中是保守的。这个提议的中心假设是，细胞动力学收缩环在裂解位点从一个宽带的前体节点逐渐组装成一个复杂的蛋白质结构。肌动蛋白交联蛋白和波罗激酶在组装过程中发挥重要的结构和信号作用。本论文基于背景研究的坚实基础和大量的初步数据，通过以下三个具体目标来验证这一假说：1）阐明苯胺醛Mid 1 p在结形成中的作用，并鉴定其在结中的结合伙伴; 2）确定肌动蛋白交联蛋白Fimalin和1-actinin在结结合成收缩环中的作用; 3）探索触发结形成和结凝结成收缩环的信号通路。在这些研究中将采用细胞、遗传、生物化学和共聚焦显微镜方法的组合。这项研究意义重大，因为它将揭示蛋白质如何在胞质分裂的收缩环组装过程中共同工作，以及苯胺mid 1 p如何通过与进化上保守的结构和信号蛋白相互作用来启动收缩环的组装。识别的装配的必要收缩环是一个重要的一步，了解胞质分裂。此外，它将帮助我们了解其他细胞过程中复杂的肌动球蛋白收缩系统。 公共卫生相关性：不受控制和错误的细胞分裂是癌症的定义特征。收缩环是微小的肌肉样产生力的结构，是胞质分裂和其他过程（包括红细胞去核、形态发生上皮关闭、上皮伤口愈合和凋亡细胞挤出）的常见机制。因此，我们所了解的关于胞质分裂中进化上保守的蛋白质的大部分内容最终与癌症和其他人类疾病相关并适用。