de Priester W, Bakker A, Lamers G
Department of Biology, Leiden University, The Netherlands.
Eur J Cell Biol. 1990 Feb;51(1):23-32.
Capping of Concanavalin A (Con A) receptors can be inhibited in Dictyostelium by treatment of amoebae with the microtubular drug tubulozole. In cells that were incubated with Con A or with fluorescent Con A conjugate the capping process was completed in 30 min as could be demonstrated by fluorescence microscopy and Con A peroxidase labeling. In the presence of 10(-5) M tubulozole redistribution of the receptors did not proceed beyond a stage that can be characterized as patching. The effect of the drug on microtubule integrity was checked by electron microscopy and immunofluorescence of tubulin. Treatment resulted in shortening of the peripheral parts of the microtubules, in agreement with results described by other authors. Electron microscopy confirmed that the Con A receptor complexes remained on the plasma membrane and were not internalized. The distribution of F-actin in Con A-treated cells showed a pattern closely resembling that of Con A. Cells that were also treated with tubulozole remained spherical and did not resume significant directional movement until tubulozole was removed from the medium. It is concluded that microtubules are involved in the rearrangement of the microfilament network in moving cells.
用微管药物tubulozole处理盘基网柄菌中的变形虫，可抑制伴刀豆球蛋白A（Con A）受体的帽化。在用Con A或荧光Con A偶联物孵育的细胞中，帽化过程在30分钟内完成，这可通过荧光显微镜和Con A过氧化物酶标记来证明。在存在10⁻⁵ M tubulozole的情况下，受体的重新分布不会超过可被描述为成斑的阶段。通过电子显微镜和微管蛋白的免疫荧光检查了该药物对微管完整性的影响。处理导致微管周边部分缩短，这与其他作者描述的结果一致。电子显微镜证实，Con A受体复合物保留在质膜上，未被内化。在Con A处理的细胞中，F-肌动蛋白的分布呈现出与Con A非常相似的模式。同时用tubulozole处理的细胞保持球形，直到从培养基中去除tubulozole后才恢复明显的定向运动。结论是微管参与了运动细胞中微丝网络的重排。
