ANALYSIS OF RAT NONMUSCLE MYOSIN HEAVY CHAIN GENE

非肌肉(Nm)肌球蛋白是细胞骨架的重要组成部分，是一种复合体。 协调细胞质分裂等细胞功能的细胞内网络， 运动和肌肉收缩。最近的研究表明， 缺乏肌球蛋白重链(MHC)的网囊藻是活的、能动的和 吞噬细胞，尽管它们表现出明显的异常胞质分裂。在……里面 在分裂哺乳动物细胞的过程中，纳米肌球蛋白定位于卵裂沟 细胞质分裂；显微注射活细胞内的标记肌球蛋白轻链 定位于乳沟，并重新结合为压力 完成胞质分裂时的纤维。NM肌球蛋白可能也是必需的 对于肌节组装，因为细胞骨架必须充当脚手架 为了合成肌节收缩蛋白，通过 协译组装。 基因靶向的令人兴奋的进展现在使靶向成为可能 通过同源重组获得不可选择的基因。初步数据显示 纳米MHC基因是由一个或几个基因编码的 瞄准是可行的。这个项目的主要目标是完成 纳米MHC基因的克隆和鉴定，以便开始基因 同源重组的破坏实验。通过扰乱纳米 我们应该能够阐明MHC在小鼠非细胞和肌肉细胞中的作用 纳米MHC在胞质分裂、细胞运动和肌节组装中的作用。进一步 研究将集中于识别那些赋予特定基因结构域的基因 在肌肉和非肌肉中都对纳米MHC蛋白起作用。

Nonmuscle (nm) myosin is an essential part of the cytoskeleton, a complex intracellular network that orchestrates such cell functions as cytokinesis, motility, and muscle contraction. Recent work has demonstrated that dictyostelium lacking myosin heavy chain (mhc) are viable, motile, and phagocytic, although they demonstrate markedly abnormal cytokinesis. In dividing mammalian cells, nm myosin localizes to the cleavage furrow during cytokinesis; labeled myosin light chains microinjected into living cells localize in the cleavage furrow, and become reincorporated into stress fibers at the completion of cytokinesis. Nm myosin may also be necessary for sarcomere assembly, because the cytoskeleton must act as a scaffolding for synthesis of the sarcomeric contractile proteins to occur by cotranslational assembly. Exciting advances in gene targeting now make it possible to target nonselectable genes by homologous recombination. Preliminary data suggests that the nm mhc gene is encoded by one or a few genes making such gene targeting feasible. The primary goal of this project is to complete the cloning and characterization of the nm mhc gene, in order to begin gene disruption experiments by homologous recombination. By disrupting the nm mhc in mouse non and muscle cells, we should be able to elucidate the role of nm mhc in cytokinesis, cell motility and sarcomere assembly. Further studies will focus on identifying those gene domains that confer specific functions to the nm mhc protein in both muscle and nonmuscle.