Cell Cycle dependent changes in myosin 1 functions

肌球蛋白在推动广泛的运动过程中起着核心作用。这些过程的多样性反映在我们细胞中发现的大量肌球蛋白马达上。目前，已鉴定出39个编码人类肌球蛋白的基因，它们被分为12个不同的类别。盘基网柄菌是一种高度能动性的生物体，可以依赖于生长条件作为独立的细胞存在或相互作用形成多细胞结构，相比之下，属于I(7)、II(1)、V(1)、VII(1)和XIV(1)类的11个肌球蛋白的组成要少得多。值得注意的是，Dictyostelials缺乏已知的向后移动的VI和IX类肌球蛋白。因此，我们推测肌动蛋白从细胞外周向内的转运是由I类肌球蛋白介导的。我们将采用直接的体内和体外功能分析来证明L类肌球蛋白肌球蛋白-IC负责这一活性。此外，我们将使用蛋白质工程方法并比较单头和双头肌球蛋白V结构的功能行为，以阐明允许这种马达蛋白以一种明显的进行性方式运输囊泡的结构特征，以对抗细胞内的PN力。

Myosins play a central role driving a wide range of motile processes. The diversity of these processes is reflected by the large number of myosin motors that are found in our cells. Currently, genes encoding 39 human myosins have been identified, which are classified in 12 distinct classes. Dictyostelium discoideum, a highly motile organism that can dependent on growth conditions exist as independent cells or interact to form multicellular structures, has in comparison a much smaller complement of 11 myosins belonging to classes I (7), II (1), V (1), VII (1), and XIV (1). Notably, Dictyostelium lacks known backwards moving myosins from class VI and IX. Therefore, we speculate that actin-based, inwards-directed transport from the cell periphery is mediated by a class I myosin. We will employ direct functional in vivo and in vitro assays to show that the class-l myosin myosin-IC is responsible for this activity. Additionally, we will use protein engineering approaches and compare the functional behavior of single and double-headed myosin V constructs, to elucidate the structural features that allow this motor protein to transport vesicles in an apparently processive fashion against pN forces inside the cell.