Developmental control of organelle transport

细胞器运输的发育控制

• 批准号: 6543386
• 负责人: MICHAEL Andreas WELTE
• 金额: $ 25.16万
• 依托单位: BRANDEIS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-08-01 至 2007-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6543386
• 关键词: Drosophilidae; biological fluid transport; dynein ATPase; embryo /fetus; embryogenesis; gene expression; gene mutation; growth /development; intracellular transport; lipid transport; microtubules; molecular cloning; organelles; polymerase chain reaction; protein isoforms; protein structure function; vesicle /vacuole; western blottings

DESCRIPTION (provided by applicant): The long-term goals of this proposal are to understand the regulatory mechanisms that allow organelle transport to be integrated with development. Motor-driven transport along microtubules plays many essential cellular roles, yet the mechanisms with which cells control its specificity, timing and destination remain a mystery. A newly developed model system, lipid-droplet motion in Drosophila embryos, provides the opportunity to attack this long-standing problem in cell biology with an interdisciplinary approach utilizing genetic, biophysical, and molecular techniques. 1) Experiments are proposed to establish how the Halo protein, a novel trans-acting regulator, mediates developmental transitions in droplet transport. The temporal expression and intracellular localization of Halo will be monitored to test whether Halo is the signal that determines timing and directionality of transport and whether Halo physically associates with motors on droplets. A structure-function analysis will be employed to generate models about Halo's biochemical activity. Nanometer-scale tracking and stall-force measurements with optical tweezers in wild-type and mutant embryos will determine at the single-organelle level which physical parameters of motion Halo controls. 2) To identify additional determinants of transport directionality, new mutations altering net droplet transport will be isolated. The genes defined by these mutations will be molecularly cloned, and their physical and functional interactions with known components of the droplet transport machinery will be established. Genes also important for other transport pathways will be preferentially analyzed to define key general regulators of organelle motility. 3) To investigate how organelle-specificity of transport is established, the targeting of cytoplasmic dynein to several embryonic cargoes will be compared. In particular, the hypothesis will be tested that different isoforms of the intermediate chain of cytoplasmic dynein recruit the motor to yolk vesicles, lipid droplets, and mitochondria. Understanding how microtubule motors are controlled has broad significance for human health since aberrant motor function has been linked to diseases ranging from birth defects to cancer, schizophrenia and Alzheimer's disease.

描述（由申请人提供）：该提案的长期目标是了解使细胞器运输与发育相结合的调控机制。沿着微管的电机驱动运输发挥着许多重要的细胞作用，但细胞控制其特异性、时间和目的地的机制仍然是个谜。新开发的模型系统——果蝇胚胎中的脂滴运动，为利用遗传、生物物理和分子技术的跨学科方法解决细胞生物学中长期存在的问题提供了机会。 1）建议进行实验来确定 Halo 蛋白（一种新型反式作用调节因子）如何介导液滴运输的发育转变。将监测 Halo 的时间表达和细胞内定位，以测试 Halo 是否是决定运输时间和方向性的信号，以及 Halo 是否与液滴上的马达有物理联系。将采用结构功能分析来生成有关 Halo 生化活性的模型。在野生型和突变型胚胎中使用光镊进行纳米级跟踪和失速力测量将在单细胞器水平上确定 Halo 控制的运动物理参数。 2）为了确定传输方向性的其他决定因素，将分离出改变净液滴传输的新突变。这些突变定义的基因将被分子克隆，并且它们与液滴运输机制的已知组件的物理和功能相互作用将被建立。将优先分析对其他运输途径也很重要的基因，以确定细胞器运动的关键通用调节因子。 3) 为了研究如何建立细胞器特异性的运输，将比较细胞质动力蛋白对几种胚胎货物的靶向。特别是，将测试以下假设：细胞质动力蛋白中间链的不同亚型将马达募集到卵黄囊泡、脂滴和线粒体。了解微管电机的控制方式对人类健康具有广泛的意义，因为异常的运动功能与出生缺陷、癌症、精神分裂症和阿尔茨海默病等疾病有关。