Molecular Mechanism of the Cytoplasmic Dynein-Dynactin Motor Complex

项目总结/摘要 细胞质动力蛋白-动力蛋白马达复合物的分子机制 我们的长期目标是阐明细胞质动力蛋白-动力肌动蛋白运动复合体的分子机制， 并确定人类动力蛋白相关疾病的分子基础。微管运动细胞质 动力蛋白与其调节蛋白协同作用，驱动胚胎发育所必需的几个过程。 发育，包括神经元增殖，神经元迁移，以及许多细胞内的运输。 货物。因此，动力蛋白功能障碍导致出生缺陷并不奇怪。一个鲜明的例子是 无脑回畸形（LIS），一种罕见但破坏性的脑畸形。这种疾病的变种是由损失或 动力蛋白调节子Lis 1的突变。在无脑回畸形中，神经元在发育过程中不能正常迁移 受影响的婴儿的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发育迟滞，往往在出生后第一年死亡。 不幸的是，对动力蛋白功能及其受Lis 1调节的机制性认识是有限的，阻碍了我们对动力蛋白的研究。 理解LIS和其他动力蛋白相关人类疾病的分子基础的能力。在本提案中，我们 将结合联合收割机单分子荧光和光学镊子为基础的力的测量与创新 蛋白质工程，以确定细胞质动力蛋白如何与其激活剂动力蛋白和货物复合 adaptor bicaudal D（BicD），由Lis 1调控。我们将破译Lis 1如何调节运动和力 产生动力蛋白-动力蛋白-BicD（DDB）运动复合物，并确定人类疾病的影响 Lis 1-DDB功能的突变。这些研究将为动力蛋白相关疾病提供新的认识， 并阐明未来治疗干预的分子靶点。

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.