Safiejko-Mroczka B, Bell P B
Department of Zoology, The University of Oklahoma, Norman, Oklahoma, 73019, USA.
Exp Cell Res. 1998 Aug 1;242(2):495-514. doi: 10.1006/excr.1997.3871.
The organization of actin, tubulin, and vimentin was studied in protruding lamellae of human fibroblasts induced by the aminoglycoside antibiotic neomycin, an inhibitor of the phosphatidylinositol cycle. Neomycin stimulates the simultaneous protrusion of lamellae in all treated cells, and the lamellae remain extended for about 15-20 min, before gradually withdrawing. The pattern and distribution of actin, tubulin, and vimentin during neomycin stimulation were analyzed by fluorescence and electron microscopy. F-actin in the newly formed lamellae is localized in a marginal band at the leading edge. Tubulin is colocalized with F-actin in the marginal band, but the newly formed lamellae are initially devoid of microtubules. Over a period of 10 to 20 min after the addition of neomycin, microtubules grow into the lamellae from the adjacent cytoplasm, while the intensity of tubulin staining of the marginal band decreases. Distribution of vimentin remains unchanged in neomycin-treated cells and vimentin filaments do not enter the new protrusions. Treatment of cells with colchicine and Taxol do not inhibit neomycin-induced protrusion but protrusions are no longer localized at the ends of cell processes and occur all around the cell periphery. We conclude that actin filaments are the major component of the cytoskeleton involved in generating protrusions. Microtubules and, possibly, intermediate filaments control the pattern of protrusions by their interaction with actin filaments.
研究了氨基糖苷类抗生素新霉素（一种磷脂酰肌醇循环抑制剂）诱导的人成纤维细胞突出薄片中肌动蛋白、微管蛋白和波形蛋白的组织情况。新霉素刺激所有处理细胞中薄片同时突出，薄片在逐渐缩回之前会持续伸展约15 - 20分钟。通过荧光显微镜和电子显微镜分析了新霉素刺激过程中肌动蛋白、微管蛋白和波形蛋白的模式和分布。新形成薄片中的F - 肌动蛋白定位于前缘的边缘带。微管蛋白与边缘带中的F - 肌动蛋白共定位，但新形成的薄片最初没有微管。添加新霉素后10至20分钟内，微管从相邻细胞质生长到薄片中，而边缘带的微管蛋白染色强度降低。波形蛋白在新霉素处理的细胞中的分布保持不变，波形蛋白丝不进入新的突出物。用秋水仙碱和紫杉醇处理细胞不会抑制新霉素诱导的突出，但突出不再局限于细胞突起的末端，而是出现在细胞周边的所有部位。我们得出结论，肌动蛋白丝是参与产生突出的细胞骨架的主要成分。微管以及可能的中间丝通过与肌动蛋白丝的相互作用控制突出的模式。
