Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo, 153-8902, Japan.
Centre for Promotion of International Education and Research, Faculty of Agriculture, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan.
Sci Rep. 2022 Sep 14;12(1):15417. doi: 10.1038/s41598-022-19589-4.
Kinesin-14 microtubule-based motors have an N-terminal tail attaching the catalytic core to its load and usually move towards microtubule minus ends, whilst most other kinesins have a C-terminal tail and move towards plus ends. Loss of conserved sequences external to the motor domain causes kinesin-14 to switch to plus-end motility, showing that an N-terminal attachment is compatible with plus-end motility. However, there has been no systematic study on the role of attachment position in minus-end motility. We therefore examined the motility of monomeric kinesin-14s differing only in their attachment point. We find that a C-terminal attachment point causes kinesin-14s to become plus-end-directed, with microtubule corkscrewing rotation direction and pitch in motility assays similar to that of kinesin-1, suggesting that both C-kinesin kinesins-14 and N-kinesin kinesin-1 share a highly conserved catalytic core function with an intrinsic plus-end bias. Thus, an N-terminal attachment is one of the requirements for minus-end motility in kinesin-14.
驱动蛋白-14 基于微管的分子马达具有一个 N 端尾部，将催化核心与其负载物连接起来，通常朝着微管的负端移动，而大多数其他驱动蛋白则具有 C 端尾部，朝着正端移动。在马达结构域之外的保守序列缺失会导致驱动蛋白-14 切换到正端运动，这表明 N 端连接与正端运动兼容。然而，对于负端运动中附着位置的作用还没有进行系统的研究。因此，我们研究了仅在附着点不同的单体驱动蛋白-14 的运动。我们发现 C 端附着点会导致驱动蛋白-14 成为正端定向的，在微管旋转实验中，微管的螺旋旋转方向和螺距与驱动蛋白-1 相似，这表明 C 驱动蛋白-14 和 N 驱动蛋白-1 都具有高度保守的催化核心功能，并具有内在的正端偏向性。因此，N 端连接是驱动蛋白-14 负端运动的要求之一。
