细胞内的物质运输是细胞的基本生理活动。在动物细胞中，微管和微丝分别承担物质的长距离和短距离的运输。然而最近，一种新型的不依赖微管的长距离运输方式被逐渐证实。在鼠卵母细胞等细胞中，待运输的囊泡表面结合有分子马达蛋白和微丝组装蛋白。囊泡可以自发组装微丝，形成遍布细胞质的微丝网络。囊泡沿该微丝网络长距离运动到细胞周边。囊泡作为该运输网络的马达动力中心和微丝组织中心，其运动和微丝生成之间如何协调的关键问题仍不清楚。本项目基于鼠卵母细胞囊泡的结合蛋白：分子马达Myo5b、肌动蛋白成核因子Spire和GTP酶Rab11a等，通过活性测定、单分子和荧光动力学等手段，完成以下目标：1）Rab11a和成核因子Spire对Myo5b运动活性的影响；2）Myo5b对Spire等蛋白的微丝聚合的影响；3）体外构建基于Rab11a/Myo5b/Spire复合体的运动和成丝系统，以明确囊泡运动和微丝生成之间的调节关系

Intracellular cargo transport is the basic physiological activity of cells. In animal cells, microtubules and microfilaments are responsible for long-distance and short-distance transport of cargoes, respectively. Recently, however, a new type of long-distance transportation that does not rely on microtubules is confirmed. In murine oocytes, the surface of the vesicle to be transported is bound with molecular motor protein and microfilament nucleation protein. The vesicles can spontaneously assemble microfilaments to form a microfilaments network in cytoplasm, and move along the microfilament network over long distances to cell membrane. As the motor motility center and microfilament organization center of the transportation network, how to coordinate the movement and microfilament generation of vesicles is still poorly understood. Based on molecular motor Myo5b, actin nucleation factor Spire and GTPase Rab11a, etc. on vesicles in murine oocyte, in this study, we will take a multidisciplinary approach (ATPase activity measurement, single-molecule experiments, fluorescence kinetics and other assays) to investigate the following goals: 1) the effect of Rab11a and the nucleation factor Spire on the motor activity of Myo5b; 2) the effects of Myo5b on Spire's actin nucleation activity; 3) In vitro reconstitution of a movement and microfilament formation system based on the Rab11a/Myo5b/Spire complex. The project will reveal the synergistic relationship between vesicles movement and microfilament generation.