Wide-ranging effects of eight cytochalasins and latrunculin A and B on intracellular motility and actin filament reorganization in characean internodal cells
Wide-ranging effects of eight cytochalasins and latrunculin A and B on intracellular motility and actin filament reorganization in characean internodal cells
复制标题
DOI：
10.1093/pcp/pcm030
复制
发表时间：
2007-04-01
影响因子：
4.9
通讯作者：
Wasteneys, Geoffrey O.
中科院分区：
文献类型：
--
作者：
Foissner, Ilse;Wasteneys, Geoffrey O.
已鉴定出多种形式的细胞松弛素，尽管它们具有共同的生物活性，但它们的效力可能有很大差异。我们研究了细胞松弛素 A、B、C、D、E、H 和 J 以及二氢细胞松弛素 B 在理想的细胞运动实验系统（蟹类藻类 Nitella pseudoflabellata 的巨型节间细胞）中的作用。发现细胞松弛素 D (60 μM) 和 H (30 μM) 最适合快速且可逆地抑制基于肌动蛋白的运动，而细胞松弛素 A 和 E 在较低浓度下阻止流动，但不可逆。我们观察到细胞松弛素抑制运动的能力与发生肌球蛋白依赖性运动的皮质下肌动蛋白束轨道的实际破坏之间没有明显的相关性。事实上，肌动蛋白束在流式传输停止时保持完整，并且仅在处理一到几天后才分解。即使使用的浓度低于抑制细胞质流动所需的浓度，所有细胞松弛素也会诱导更不稳定的皮质肌动蛋白丝重组为肌动蛋白斑、旋转簇或短杆。 Latrunculins A 和 B 仅在破坏皮质下肌动蛋白束后才阻止流动，该过程需要相对高的浓度（200 μM）和 > 1 d 的非常长的治疗周期。然而，Latrunculins 与细胞松弛素具有协同作用。用 15 nM latrunculin A 和 4 μM 细胞松弛素 D 处理 1 小时，诱导皮质下肌动蛋白束可逆断裂并阻止细胞质流动。我们的研究结果提供了对细胞松弛素和latrunculins干扰Characean肌动蛋白以抑制运动的机制的见解。
Numerous forms of cytochalasins have been identified and, although they share common biological activity, they may differ considerably in potency. We investigated the effects of cytochalasins A, B, C, D, E, H and J and dihydrocytochalasin B in an ideal experimental system for cell motility, the giant internodal cells of the characean alga Nitella pseudoflabellata. Cytochalasins D (60 mu M) and H (30 mu M) were found to be most suited for fast and reversible inhibition of actin-based motility, while cytochalasins A and E arrested streaming at lower concentrations but irreversibly. We observed no clear correlation between the ability of cytochalasins to inhibit motility and the actual disruption of the subcortical actin bundle tracks on which myosin-dependent motility occurs. Indeed, the actin bundles remained intact at the time of streaming cessation and disassembled only after one to several days' treatment. Even when applied at concentrations lower than that required to inhibit cytoplasmic streaming, all of the cytochalasins induced reorganization of the more labile cortical actin filaments into actin patches, swirling clusters or short rods. Latrunculins A and B arrested streaming only after disrupting the subcortical actin bundles, a process requiring relatively high concentrations (200 mu M) and very long treatment periods of > 1 d. Latrunculins, however, worked synergistically with cytochalasins. A 1 h treatment with 15 nM latrunculin A and 4 mu M cytochalasin D induced reversible fragmentation of subcortical actin bundles and arrested cytoplasmic streaming. Our findings provide insights into the mechanisms by which cytochalasins and latrunculins interfere with characean actin to inhibit motility.