Biomechanics of the Cell Nucleus: The Role of Chromatin and its Connectivity with Nuclear Proteins and the Nuclear Membrane

细胞核的生物力学：染色质的作用及其与核蛋白和核膜的连接

• 批准号: 1334406
• 负责人: Simon Mochrie
• 金额: $ 38万
• 依托单位: Yale University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-09-01 至 2016-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1334406&HistoricalAwards=false
• 关键词: Biomechanics; Cell; Nucleus; Role; Chromatin

The research objective of this award is to examine how individual nuclear components contribute to the mechanical properties of the cell nucleus using a novel optical-tweezers assay in conjunction with nuclei from the genetically-facile fission yeast, S. pombe. Studies conducted under this award will test how altering the size of the nucleus, the compaction of the genome, the fluidity of the nuclear membrane, and association of chromatin with the nuclear envelope affect nuclear mechanical properties. Lamins, which are key in determining the mechanical properties of mammalian nuclei, but do not occur natively in S. pombe, will be introduced heterologously to dissect their mechanical properties from their roles in mammalian signaling and gene regulation. Fluorescence imaging of specific chromosome locations during force application to the S. pombe LINC complex, which spans the nuclear membrane, will elucidate how force is communicated into the nuclear mechanical network.If successful, these studies will elucidate how the mechanics of the nucleus emerge from its constituents, and delineate how the mechanical environment, which is essential for the differentiation programs that give rise to specific cell types, is communicated to the nucleus, where cell fate is largely determined. They will also establish S. pombe as a model system in which the mechanical role of lamins can be decoupled from their regulatory functions, thus providing a platform for future studies of lamin mutants that cause such diseases as lipodystrophy, muscular dystrophy, and progeria. Because embryonic stem (ES) cells and yeast express very low levels or no lamins, respectively, these studies will also lead to new insights into how extracellular mechanical cues drive ES cell differentiation. On the educational side, the students involved in these studies will become a new generation of teacher-scientists, who excel at quantitative approaches and possess the biological sophistication to identify and tackle cutting-edge biological problems.

该奖项的研究目标是使用一种新的光镊法结合遗传易感性的分裂酵母S.pombe的细胞核来研究单个核成分如何对细胞核的机械性能做出贡献。根据该奖项进行的研究将测试改变核的大小、基因组的紧凑程度、核膜的流动性以及染色质与核膜的关联如何影响核的机械性能。层粘连蛋白是决定哺乳动物细胞核机械性质的关键因素，但不是天然存在于庞氏链霉菌中。我们将通过异源引入层粘连蛋白来分析它们在哺乳动物信号转导和基因调控中的作用。在对跨越核膜的S.pombe LINC复合体施加力的过程中，对特定染色体位置的荧光成像将阐明力是如何传递到核机械网络中的。如果成功，这些研究将阐明核的力学机制是如何从其成分中产生的，并描绘出机械环境是如何传递到细胞核的，这是产生特定细胞类型的分化程序所必需的，在那里细胞的命运在很大程度上是由细胞核决定的。他们还将建立S.pombe作为一个模型系统，其中lamins的机械作用可以从它们的调节功能中分离出来，从而为未来研究导致脂肪营养不良、肌肉营养不良和早衰症等疾病的lamin突变提供一个平台。由于胚胎干细胞和酵母分别表达极低水平的层蛋白或不表达层蛋白，这些研究也将导致对细胞外机械信号如何驱动ES细胞分化的新见解。在教育方面，参与这些研究的学生将成为新一代教师科学家，他们擅长定量方法，并拥有识别和解决尖端生物学问题的生物学尖端技术。