MYOSIN-I IS LOCATED AT THE LEADING EDGES OF LOCOMOTING DICTYOSTELIUM AMEBAS
MYOSIN-I IS LOCATED AT THE LEADING EDGES OF LOCOMOTING DICTYOSTELIUM AMEBAS
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DOI：
10.1038/341328a0
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发表时间：
1989-09-28
期刊：
影响因子：
64.8
通讯作者：
KORN, ED
中科院分区：
文献类型：
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作者：
FUKUI, Y;LYNCH, TJ;KORN, ED
真核细胞沿着底物的运动是通过细胞前部板足和伪足的伸展和后部的收缩来实现的。这些运动的分子和结构机制尚不确定。盘状盘基骨菌含有两种形式的肌凝蛋白。在这里，我们通过免疫荧光显微镜显示，非丝状肌球蛋白I出现在迁移的dictyosteliumamoebae板足状突起的前缘，这是缺乏肌球蛋白II的，而丝状肌球蛋白II集中在细胞的后部。基于这两种形式肌凝蛋白的位置以及它们已知的生化和生物物理特性，我们认为肌动凝蛋白I可能有助于导致运动细胞前缘伸展的力，而肌动凝蛋白II在后方的收缩使细胞团向前挤压。肌球蛋白I同工酶可能在后生动物细胞中有类似的作用，例如在神经元生长锥的前缘和延伸处
MOVEMENT of a eukaryotic cell along a substrate occurs by extension of lamellipodia and pseudopodia at the anterior and retraction at the posterior of the cell. The molecular and structural mechanisms of these movements are uncertain.Dictyostelium discoideumcontains two forms of myosin. Here we show by immuno-fluorescence microscopy that non-filamentous myosin I occurs at the leading edges of the lamellipodial projections of migratingDictyosteliumamoebae, which are devoid of myosin II, whereas filamentous myosin II is concentrated in the posterior of the cells. On the basis of these locations of the two forms of myosin and their known biochemical and biophysical properties, we suggest that actomyosin I may contribute to the forces that cause extension at the leading edge of a motile cell, while the contraction of actomyosin II at the rear squeezes the cell mass forward. Myosin I isozymes might have similar roles in metazoan cells, for example at the leading edges of neuronal growth cones, and in the extension