Molecular Mechanism of the Cytoplasmic Dynein-Dynactin Motor Complex

上级奖项项目摘要/摘要 标题：细胞质动力蛋白-动力蛋白马达复合体的分子机制 我们的长期目标是阐明细胞质动力蛋白-动力蛋白马达复合体的分子机制， 并确定人类动力蛋白相关疾病的分子基础。微管运动胞质 动力蛋白与它的调节蛋白合作，驱动了几个对胚胎至关重要的过程 发育，包括神经元的增殖、神经元的迁移和许多细胞内的运输 货物。因此，动力蛋白失调导致出生缺陷也就不足为奇了。一个引人注目的例子是 无脑畸形(LIS)，一种罕见但毁灭性的大脑畸形。这种疾病的变种是由于丢失或 动力蛋白调节基因Lis1的突变。在无脑发育过程中，神经元不能正常迁移 受影响的婴儿大脑缺乏正常的脑回折叠模式和大脑皮层的分层。这些 儿童患有无法治愈的癫痫和严重的精神运动迟缓，通常在出生后第一年死亡。 不幸的是，对dynein功能及其由Lis1调控的机械论见解是有限的，阻碍了我们的 了解LIS和其他动力蛋白相关人类疾病的分子基础的能力。在这项提案中，我们 将单分子荧光和基于光钳的测力与创新的 蛋白质工程以确定细胞质动力蛋白与其激活剂动力蛋白和货物的复合体 接头双尾端D(BicD)，受Lis1调控。我们将破译LIS1是如何调节运动和力的 动力蛋白-动力蛋白-BicD(DDB)运动复合体的产生，并确定人类疾病的影响 Lis1-DDB功能突变。这些研究将提供对动力蛋白相关疾病的新理解， 并阐明未来治疗干预的分子靶点。

PARENT AWARD PROJECT SUMMARY/ABSTRACT Title: Molecular Mechanism of the Cytoplasmic Dynein-Dynactin Motor Complex Our long-term goal is to elucidate the molecular mechanism of the cytoplasmic dynein-dynactin motor complex, and to define the molecular bases of dynein-related diseases in humans. The microtubule motor cytoplasmic dynein, in cooperation with its regulatory proteins, drives several processes essential to embryonic development, including neuronal proliferation, neuronal migration, and the transport of numerous intracellular cargoes. Thus, it is not surprising dysfunction of dynein contributes to birth defects. A striking example is lissencephaly (LIS), a rare, but devastating brain malformation. Variants of this diseases are caused by loss or mutation of the dynein regulator Lis1. In lissencephaly, neurons fail to migrate properly during development and affected infants’ brains lack the normal gyral folding pattern and layering of the cerebral cortex. These children suffer untreatable epilepsy and severe psychomotor retardation, often dying in the first year of life. Unfortunately, mechanistic insights into dynein function and its regulation by Lis1 are limited, hampering our ability to understand the molecular basis for LIS, and other dynein-linked human diseases. In this proposal, we will combine single-molecule fluorescence and optical tweezers-based force measurements with innovative protein engineering to determine how cytoplasmic dynein in complex with its activator dynactin and the cargo adaptor bicaudal D (BicD), is regulated by Lis1. We will decipher how Lis1 regulates the motion and force generation of the dynein-dynactin-BicD (DDB) motor complex, and determine the effects of human disease mutations on Lis1-DDB function. These studies will provide a new understanding of dynein-linked diseases, and elucidate molecular targets for future therapeutic interventions.