Ichikawa Y, Nagata K, Sagara J
Acta Pathol Jpn. 1982;32 Suppl 1:187-96.
In this report we tried to draw a sketch of our recent work on the changes in actomyosin system during the differentiation of a myeloid leukemia cell line (M1). Before the differentiation, the M1 cells do not have a locomotive and phagocytic activity but do after the differentiation. The rather peculiar properties of actin shown by the leukemic M1 cells, low polymerizability and low affinity to myosin ATPase as well as the presence of polymerization inhibitor may explain their inability of motility and phagocytosis. Enhanced binding of actin and myosin on the plasma membrane looks necessary to carry out those differentiated functions which must need vigorous movement of the membrane. The cell movement also anticipates cell deformability which accompanies gelation in a part of cytoplasm and solation in another part. We have already isolated several gelation-factors as well as inhibitors. Not only chemical modifications of actin and myosin molecules but also quantitative variations in those regulatory proteins must be taken into consideration. Thus, studies on the cellular contractile proteins are casting a new light on the process of differentiation of the M1 cell line.
在本报告中，我们试图勾勒出我们近期关于髓系白血病细胞系（M1）分化过程中肌动球蛋白系统变化的研究概况。在分化之前，M1细胞不具有运动和吞噬活性，但分化后则具有。白血病M1细胞所表现出的肌动蛋白相当特殊的特性，即低聚合能力、对肌球蛋白ATP酶的低亲和力以及存在聚合抑制剂，可能解释了它们缺乏运动性和吞噬作用的原因。肌动蛋白和肌球蛋白在质膜上的结合增强似乎是执行那些必须需要膜剧烈运动的分化功能所必需的。细胞运动也预示着细胞可变形性，这伴随着细胞质一部分的凝胶化和另一部分的溶胶化。我们已经分离出了几种凝胶化因子以及抑制剂。不仅要考虑肌动蛋白和肌球蛋白分子的化学修饰，还要考虑这些调节蛋白的数量变化。因此，对细胞收缩蛋白的研究为M1细胞系的分化过程带来了新的启示。
