Cell growth control by cell and organelle size-dependent ribosome biogenesis

通过细胞和细胞器大小依赖性核糖体生物发生控制细胞生长

• 批准号: 8355129
• 负责人: Clifford P Brangwynne
• 金额: $ 241.5万
• 依托单位: PRINCETON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-30 至 2017-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8355129
• 关键词: Algorithms; Binding; Biogenesis; Biological Assay; Biological Process; Caenorhabditis elegans; Cell Cycle; Cell Growth Processes; Cell Nucleolus; Cell Size; Cells; Custom; Databases; Dependence; Diploidy; Disease; Embryonic Development; Feedback; Genomics; Growth; Homeostasis; Image; Image Analysis; Individual; Liquid substance; Malignant Neoplasms; Measures; Metabolic Pathway; Modeling; Nuclear; Organelles; Organism; Pathway interactions; Phase; Physiological; Play; Ploidies; RNA Processing; Regulation; Ribonucleoproteins; Ribosomal RNA; Ribosomes; Role; Signal Transduction; System; Testing; Thinking; Xenopus oocyte; abstracting; base; carcinogenesis; cell growth; liquid dynamics; novel; public health relevance

DESCRIPTION (Provided by the applicant) Abstract: Biological processes ranging from embryonic development to carcinogenesis rely on the regulation or dysregulation of cell growth and size; despite this central biomedical importance, the mechanisms by which cells ""know"" to grow to a certain size remain poorly understood. With few exceptions, virtually all current thinking about cell size control is based on traditional paradigms that focus on signaling networks such as the TOR metabolic pathway, or the cell cycle pathway. However, we lack even a basic mechanistic understanding of the way in which cellular variables such as genomic content (ploidy) and ribosome biosynthetic activity exert their well-known effects on cell size, particularly in the context of cell size homeostasis i multicellular organisms. The fundamental gap in our understanding of this critical biological process underscores the urgent need for new ways of quantitatively looking at cell size control. We recently introduced the novel concept that non-membrane bound ribonucleoprotein (RNP) bodies, including the ribosome-producing nucleolus, are dynamic liquid phase micro-reactors for rapid RNA processing. Our previous studies with other disordered liquid-like bodies suggest that the size of nucleoli should scale with the size of cells. However, basic biophysical considerations suggest that nucleoli of different size will produce ribosomal subunits at different rates; large nucleoli in large cells may not be able to keep up with the ribosome requirements for steady cell growth, providing a biophysical mechanism for cell size feedback and growth control. To test this hypothesis, we will use novel imaging-based assays to measure the function of individual nucleoli of different size, utilizing a biochemically accessible Xenopus oocyte system. We will then examine the consequences of this size- dependent activity, dissecting the relationship between nucleolus size and activity, and cell size, within the multicellular worm C.elegans. Using 3D confocal imaging and custom image analysis algorithms, we will measure the effects of altered nucleolus size and biosynthetic activity on cell size, in both diploid and tetraploid worms. Finally, we will develop theoretical biophysical models for understanding these data based on the size dependence of the rate of ribosomal RNA processing within the dynamic liquid- like nucleolar material. Public Health Relevance: Biological processes ranging from embryonic development to cancer all rely on the regulation or dysregulation of cell growth and size. The nucleolus is a nuclear organelle that plays a well known role in cell growth control. This proposal seeks to identify the biophysical mechanism by which the nucleolus may provide cell size feedback for regulating cell growth, which will have important implications for understanding and controlling physiological and disease driven cell growth processes.

描述（申请人提供） 摘要：从胚胎发育到致癌的生物学过程依赖于细胞生长和大小的调节或失调；尽管存在这种中心的生物医学重要性，但细胞“知道”成长为一定尺寸的机制仍然很少理解。除少数例外，几乎所有有关单元尺寸控制的当前思考均基于 传统的范例专注于信号网络，例如TOR代谢途径或细胞周期途径。但是，我们甚至缺乏对细胞变量（例如基因组含量（倍）和核糖体生物合成活性）的方式的基本机械理解，它们对细胞大小的影响，尤其是在细胞大小的稳态I多细胞生物的背景下。我们对这一关键生物学过程的理解的根本差距强调了对新方法进行定量查看细胞尺寸控制的迫切需求。 我们最近介绍了一种新的概念，即非膜结合的核糖核蛋白（RNP）体（包括产生核糖体的核仁）是用于快速RNA处理的动态液相微反应器。我们先前对其他液体样体的研究表明，核仁的大小应随细胞的大小而扩展。但是，基本的生物物理考虑表明，不同大小的核仁会在不同的地方产生核糖体亚基 费率；大细胞中的大型核仁可能无法跟上稳定细胞生长的核糖体要求，从而为细胞大小反馈和生长控制提供了生物物理机制。为了检验这一假设，我们将使用基于成像的新测定方法来测量不同尺寸的单个核仁的功能，并利用生物化学上可访问的Xenopus卵母细胞系统。然后，我们将检查这种尺寸依赖性活性的后果，从而在多细胞蠕虫岩岩中解剖核仁大小与活性以及细胞大小之间的关系。使用3D共聚焦成像和自定义图像分析算法，我们将在二倍体和四倍体蠕虫中测量核仁大小和生物合成活性改变的细胞大小的影响。最后，我们将基于动态液体（如核仁材料）内的核糖体RNA加工速率的大小依赖性来开发理论生物物理模型，以理解这些数据。 公共卫生相关性：从胚胎发育到癌症的生物学过程都依赖于细胞生长和大小的调节或失调。 Nucleolus是一种核井器，在细胞生长控制中起着众所周知的作用。该建议旨在确定核仁可以为调节细胞生长提供细胞大小的反馈的生物物理机制，这将对理解和控制生理和疾病驱动的细胞生长过程具有重要意义。

项目成果

Phase transitions and size scaling of membrane-less organelles.

• DOI: 10.1083/jcb.201308087
• 发表时间: 2013-12-23
• 期刊: The Journal of cell biology
• 作者: Brangwynne CP

Spatiotemporal Control of Intracellular Phase Transitions Using Light-Activated optoDroplets.

• DOI: 10.1016/j.cell.2016.11.054
• 发表时间: 2017-01-12
• 期刊: Cell
• 影响因子: 64.5
• 作者: Shin Y;Berry J;Pannucci N;Haataja MP;Toettcher JE;Brangwynne CP
• 通讯作者: Brangwynne CP

Soft viscoelastic properties of nuclear actin age oocytes due to gravitational creep.

• DOI: 10.1038/srep16607
• 发表时间: 2015-11-18
• 期刊: Scientific reports
• 影响因子: 4.6
• 作者: Feric M;Broedersz CP;Brangwynne CP
• 通讯作者: Brangwynne CP

The disordered P granule protein LAF-1 drives phase separation into droplets with tunable viscosity and dynamics

• DOI: 10.1073/pnas.1504822112
• 发表时间: 2015-06-09
• 期刊: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• 影响因子: 11.1
• 作者: Elbaum-Garfinkle, Shana;Kim, Younghoon;Brangwynne, Clifford P.
• 通讯作者: Brangwynne, Clifford P.

Nuclear bodies: the emerging biophysics of nucleoplasmic phases.

核体：核质相的新兴生物物理学。

• DOI: 10.1016/j.ceb.2015.04.003
• 发表时间: 2015
• 期刊: Current opinion in cell biology
• 影响因子: 7.5
• 作者: Zhu,Lian;Brangwynne,CliffordP
• 通讯作者: Brangwynne,CliffordP