Kolega J
Department of Anatomy and Cell Biology, State University of New York at Buffalo School of Medicine and Biomedical Sciences, 3435 Main Street, Buffalo, New York, USA.
Exp Cell Res. 1997 Feb 25;231(1):66-82. doi: 10.1006/excr.1996.3461.
Myosin II is required for normal amoeboid locomotion. In order to understand how myosin II elicits its effects on locomotive behavior, we have mapped myosin II-cytoskeleton interactions in locomoting endothelial cells. Bovine microcapillary endothelial cells were microinjected with fluorescently labeled myosin II, and the distribution of myosin II was imaged in the living cells by fluorescence microscopy. The same cells were then permeabilized with Triton X-100 and imaged again. The second set of images showed only myosin II that was associated with detergent-insoluble cytoskeleton. Dividing the image of retained myosin II by that of total myosin II produced a map of the extent to which myosin II was associated with the detergent-resistant cytoskeleton at any point in the cell. In cells migrating at the edge of a scrape wound, myosin II was preferentially retained in a region approximately 10 microm wide located just behind the cells' leading lamellipodia. Relatively little myosin II was retained in perinuclear cytoplasm. A vector representation of the distribution of total versus retained myosin II demonstrated that myosin II retention was sharply polarized with respect to locomotion, favoring the front of migrating cells. Myosin II-enriched cytoskeleton in this region may help polarize protrusive activity and/or move cytoplasmic bulk forward. Patches of myosin II retention were also observed in adherent tails of many cells, consistent with a role in pulling the rear of the cell forward.
肌球蛋白II是正常阿米巴样运动所必需的。为了了解肌球蛋白II如何对运动行为产生影响，我们绘制了运动中的内皮细胞中肌球蛋白II与细胞骨架的相互作用图谱。用荧光标记的肌球蛋白II对牛微血管内皮细胞进行显微注射，通过荧光显微镜对活细胞中肌球蛋白II的分布进行成像。然后用Triton X-100使相同的细胞通透化并再次成像。第二组图像仅显示与去污剂不溶性细胞骨架相关的肌球蛋白II。将保留的肌球蛋白II的图像除以总肌球蛋白II的图像，得到了细胞中任何一点上肌球蛋白II与抗去污剂细胞骨架相关程度的图谱。在刮伤伤口边缘迁移的细胞中，肌球蛋白II优先保留在细胞前缘片状伪足后方约10微米宽的区域。核周细胞质中保留的肌球蛋白II相对较少。总肌球蛋白II与保留的肌球蛋白II分布的矢量表示表明，肌球蛋白II的保留相对于运动明显极化，有利于迁移细胞的前端。该区域富含肌球蛋白II的细胞骨架可能有助于使突出活动极化和/或将细胞质向前移动。在许多细胞的附着尾部也观察到肌球蛋白II保留斑块，这与拉动细胞后部向前的作用一致。
