Regulation of formins and cell polarity in yeast

酵母中福尔明和细胞极性的调节

• 批准号: 8126615
• 负责人: Bruce L Goode
• 金额: $ 2.8万
• 依托单位: BRANDEIS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-01 至 2011-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8126615
• 关键词: Actins; Address; Affect; Animal Model; Animals; Architecture; Back; Binding; Biochemical; Biochemistry; Biological; Cell Adhesion; Cell Extracts; Cell Polarity; Cell division; Cell physiology; Cells; Cellular biology; Complex; Congenital Abnormality; Cues; Cytokinesis; Cytoskeleton; Data; Disease; Electron Microscopy; Endocytosis; Event; Exhibits; Filament; Genes; Genetic; Goals; Half-Life; Homologous Gene; Human; Inhibitory Concentration 50; Length; Life; Ligands; Malignant Neoplasms; Mammals; Mass Spectrum Analysis; Mediating; Microfilaments; Modeling; Molecular; Morphogenesis; Mothers; Mutation; Myosin ATPase; Neck; Neurodegenerative Disorders; Organelles; Organism; Pattern; Physiological; Physiology; Plants; Play; Population; Positioning Attribute; Problem Solving; Protein Family; Proteins; Recycling; Regulation; Relative (related person); Role; Saccharomyces cerevisiae; Saccharomycetales; Secretory Vesicles; Structure; System; Tertiary Protein Structure; Testing; Tissues; Transcript; Visual; Work; Yeasts; base; cell growth; cell motility; cellular imaging; fungus; in vivo; insight; interdisciplinary approach; novel; particle; polarized cell; protein structure; response; rho GTP-Binding Proteins

DESCRIPTION (provided by applicant): Our long-term goal is to gain a highly mechanistic understanding of how the actin cytoskeleton directs cell polarity and cell morphogenesis. All living cells have internal and external structures tailored to and critical for their distinctive physiological functions. Further, cell architecture can be changed rapidly in response to various cues. The mechanisms underlying these events remain poorly understood and represent a major challenge for cell biologists to define. Recently, a conserved family of proteins called formins has emerged as crucial regulators of actin assembly and remodeling in cells, often functioning directly downstream of Rho GTPases. Formins are large multi-domain proteins that play essential roles in cell polarity, cell division, cell migration, endocytosis, and cell adhesion in a wide range of organisms. Formins directly nucleate actin assembly by a novel mechanism and remain processively attached to the growing end of the filament, protecting the end from capping proteins while guiding insertion of new actin subunits. While the last five years have seen rapid progress in elucidating formin protein structure, mechanism and function, comparatively little is known about how formin activities are regulated spatially and temporally in cells. In this proposal, we will address this question using the budding yeast Saccharomyces cerevisiae as a model organism. Whereas mammals have 15 different formin genes, S. cerevisiae has only two (Bni1 and Bnr1), and hence offers a simplified model to dissect formin regulation. Yeast also allows us to take a multidisciplinary approach, combining genetics, biochemistry, and live cell imaging. Bni1 and Bnr1 have distinct localization and dynamics, and assemble two distinct sets of actin cables. These cables serve as polarized tracks required for targeted secretion and polarized cell growth. We will determine how one of these formins (Bnr1) is regulated in vivo, which will provide key mechanistic insights into the molecular basis of cell polarity and cell morphogenesis. The Specific Aims of the proposal are: (1) How is Bnr1 anchored at the bud neck, activated/released from an autoinhibited state, and then retrieved from actin filament ends for new rounds of actin assembly? (2) How are the activities and cellular functions of a novel Bnr1-regulator (Bud14) controlled by its in vivo binding partners (Kel1 and Kel2)? Defining the molecular basis of these events is critical not only for understanding normal human cell biology and physiology, but also for determining how mutations in the genes encoding morphogenetic determinants give rise to disease states including cancer, birth defects, and neurodegenerative disorders.

描述（由申请人提供）：我们的长期目标是对肌动蛋白细胞骨架如何指导细胞极性和细胞形态发生有高度机械的理解。所有活细胞均具有针对其独特生理功能的内部和外部结构。此外，可以响应各种提示而迅速更改细胞结构。这些事件的基础机制仍然很少理解，并代表了细胞生物学家定义的主要挑战。最近，一种称为formins的蛋白质家族已成为肌动蛋白组装和细胞中重塑的关键调节剂，通常在Rho GTPases的下游直接起作用。甲素是大型多域蛋白，在细胞极性，细胞分裂，细胞迁移，内吞作用和细胞粘附中起着重要作用。 formins通过一种新型的机制直接对肌动蛋白组装进行核定，并保持在细丝的生长末端的过程中，从而保护末端免于封盖蛋白质，同时指导插入新的肌动蛋白亚基。虽然过去五年在阐明formin蛋白结构，机制和功能方面取得了迅速的进展，但对于在细胞中如何在空间和时间上调节formin活性的调节却相对较少。在此提案中，我们将使用酿酒酵母作为模型有机体的萌芽酵母糖疗法来解决这个问题。哺乳动物具有15种不同的formin基因，而酿酒酵母只有两个（BNI1和BNR1），因此提供了一个简化的模型来剖析formin调节。酵母还使我们能够采用多学科方法，结合遗传学，生物化学和活细胞成像。 BNI1和BNR1具有独特的本地化和动力学，并组装了两组不同的肌动蛋白电缆。这些电缆用作靶向分泌和极化细胞生长所需的极化轨道。我们将确定如何在体内调节这些formins（BNR1）之一，这将为细胞极性和细胞形态发生的分子基础提供关键的机械见解。该提案的具体目的是：（1）BNR1如何锚定在芽颈，从自身抑制状态激活/释放，然后从肌动蛋白丝末端检索到肌动蛋白组装的新回合？ （2）如何由其体内结合伙伴（KEL1和KEL2）控制的新型BNR1-调节剂（BUD14）的活性和细胞功能如何？定义这些事件的分子基础不仅对于理解正常的人类细胞生物学和生理学至关重要，而且对于确定编码形态发生决定因素的基因中的突变如何产生疾病状态，包括癌症，源自缺陷，神经退行性疾病。