Studies on molecular organization of actin cytoskeleton in plant cells

肌动蛋白细胞骨架参与细胞质流动和细胞内结构。我们研究了植物细胞肌动蛋白、细胞骨架和相关蛋白的结构和功能。1)肌球蛋白活性的调节。以前，我们从百合花粉管中分离到了可移动的植物肌球蛋白(Yokota和Shimmen，1994)。在本研究中，我们发现肌球蛋白的活性受Ca~(2+)和gt；的调节，这是关于Ca~(2+)&gt；调控植物肌球蛋白的首次报道。我们还发现，这种肌球蛋白是以钙调蛋白为轻链的。2)两种肌球蛋白的鉴定我们发现烟草培养细胞中含有两种肌球蛋白。两种肌球蛋白均受Ca~(2+)和Gt；的调节。目前，我们正在分析这些肌球蛋白在植物细胞中的功能。3)肌动蛋白捆绑蛋白的分析之前，我们已经分离出肌动蛋白捆绑蛋白。氨基酸序列分析表明，这些肌动蛋白结合蛋白属于Villin家族。我们研究了绒毛蛋白在植物细胞肌动蛋白细丝组织中的作用。

Actin cytoskeleton is involved in cytoplasmic streaming and intracellular structure. We studied the structure and function of actin cytoskeleton and related proteins of plant cells.1) Regulation of myosin activity Ca^2Previously we had isolated motile plant myosin from lily pollen tube (Yokota and Shimmen 1994). In the present study, we found that the activity of myosin is regulated by Ca^<2+>.This is the first report of Ca^<2+> regulation of plant myosin. We also found that this myosin are equipped with calmodulin as a light chain. The present results can be a molecular basis for understanding of cytoplasmic streaming by Ca^<2+>.2) Identification of two types of myosinsWe found that tobacco cultured cells have two kinds of myosins. Both myosin was regulated by Ca^<2+>. At present, we are analyzing functions of these myosins in plant cell.3) Analysis of actin-bundling protein, villinPreviously, we had isolated actin-bundling proteins. Analysis of ammo add sequence showed that these actin-bundling proteins belong to a villin family. We studied the role of villin in organization actin filaments in plant cells.