Motility of single one-headed kinesin molecules along microtubules
Motility of single one-headed kinesin molecules along microtubules
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DOI：
10.1016/s0006-3495(01)75925-5
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发表时间：
2001-11-01
影响因子：
3.4
通讯作者：
Yanagida, T
中科院分区：
文献类型：
--
作者：
Inoue, Y;Iwane, AH;Yanagida, T
利用全内反射荧光显微镜对果蝇双头驱动蛋白的截短片段单头驱动蛋白分子（K351和K340）的运动性进行了研究。单头驱动蛋白片段沿微管连续沿着移动。对于K351和K340，直到片段从微管解离的最大行进距离类似于600 nm。该值明显大于测量系统的空间分辨率（SID约为30 nm）。虽然片段的运动在向前和向后的方向上波动，但统计分析表明，K340和K351的平均运动都朝向微管的正端，即，前进方向。当BDTC（Propionibacterium shermanii转羧酶的1.3-S亚基，与微管结合较弱）融合到K351的尾部（C-末端）时，其运动增强，平滑，单向，类似于双头驱动蛋白片段K411。然而，K351 BDTC分子的运动距离和速度比K411小3倍左右。这些观察结果表明，一个单一的驱动蛋白头有基础的运动，但两个头之间的协调是必要的稳定的基础运动的正常水平的驱动蛋白的持续合成能力。
The motility of single one-headed kinesin molecules (K351 and K340), which were truncated fragments of Drosophila two-headed kinesin, has been tested using total internal reflection fluorescence microscopy. One-headed kinesin fragments moved continuously along the microtubules. The maximum distance traveled until the fragments dissociated from the microtubules for both K351 and K340 was similar to 600 nm. This value is considerably larger than the space resolution of the measurement system (SID approximate to 30 nm). Although the movements of the fragments fluctuated in forward and backward directions, statistical analysis showed that the average movements for both K340 and K351 were toward the plus end of the microtubules, i.e., forward direction. When BDTC (a 1.3-S subunit of Propionibacterium shermanii transcarboxylase, which binds weakly to a microtubule), was fused to the tail (C-terminus) of K351, its movement was enhanced, smooth, and unidirectional, similar to that of the two-headed kinesin fragment, K411. However, the travel distance and velocity of K351 BDTC molecules were similar to3-fold smaller than that of K411. These observations suggest that a single kinesin head has basal motility, but coordination between the two heads is necessary for stabilizing the basal motility for the normal level of kinesin processivity.