Dye R B, Flicker P F, Lien D Y, Williams R C
Department of Molecular Biology, Vanderbilt University, Nashville, Tennessee.
Cell Motil Cytoskeleton. 1992;21(3):171-86. doi: 10.1002/cm.970210302.
We report a reliable method to prepare, in vitro, microtubules that are stabilized at both ends by axonemal structures, and report studies of their properties. Such "end-stabilized" microtubules neither grow nor shorten over times of several hours when tubulin subunits are present in the surrounding solution. When subunits are removed, the microtubules eventually break. Breakage occurs within a sinuous and flexible region, a few microns in length, that begins at a single point on the microtubule and grows. When breakage does occur, the resulting two free ends shorten very rapidly until the flexible part has depolymerized and the region of straight microtubule is reached. The remainder of the microtubule then shortens at rates comparable to those ordinarily observed in dynamic instability. Formation of the flexible region can be reversed if subunits are added to the buffer prior to breakage. End-stabilized microtubules are a useful tool for studying interactions of molecules with the microtubular wall. They may be a good model for interpreting stabilizing events that happen in the cell. A preliminary study of the effects of microtubule poisons on the wall is presented.
我们报告了一种在体外制备两端由轴丝结构稳定的微管的可靠方法，并报告了对其性质的研究。当周围溶液中存在微管蛋白亚基时，这种“末端稳定”的微管在数小时内既不生长也不缩短。当亚基被去除时，微管最终会断裂。断裂发生在一个弯曲且灵活的区域，该区域长度为几微米，从微管上的一个单点开始并延伸。当断裂确实发生时，产生的两个自由端会非常迅速地缩短，直到灵活部分解聚并到达直微管区域。然后微管的其余部分以与动态不稳定性中通常观察到的速率相当的速度缩短。如果在断裂前向缓冲液中添加亚基，灵活区域的形成可以逆转。末端稳定的微管是研究分子与微管壁相互作用的有用工具。它们可能是解释细胞中发生的稳定事件的良好模型。本文还介绍了对微管毒物对管壁影响的初步研究。
