Yin H, Pruyne D, Huffaker T C, Bretscher A
Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York 14853, USA.
Nature. 2000 Aug 31;406(6799):1013-5. doi: 10.1038/35023024.
Coordination of spindle orientation with the axis of cell division is an essential process in all eukaryotes. In addition to ensuring accurate chromosomal segregation, proper spindle orientation also establishes differential cell fates and proper morphogenesis. In both animal and yeast cells, this process is dependent on cytoplasmic microtubules interacting with the cortical actin-based cytoskeleton, although the motive force was unknown. Here we show that yeast Myo2, a myosin V that translocates along polarized actin cables into the bud, orientates the spindle early in the cell cycle by binding and polarizing the microtubule-associated protein Kar9 (refs 7-9). The tail domain of Myo2 that binds Kar9 also interacts with secretory vesicles and vacuolar elements, making it a pivotal component of yeast cell polarization.
纺锤体方向与细胞分裂轴的协调是所有真核生物中的一个基本过程。除了确保准确的染色体分离外，正确的纺锤体方向还能确立不同的细胞命运和正常的形态发生。在动物细胞和酵母细胞中，尽管动力未知，但这个过程依赖于细胞质微管与基于肌动蛋白的皮质细胞骨架相互作用。我们在此表明，酵母Myo2，一种沿着极化的肌动蛋白电缆转运到芽中的肌球蛋白V，通过结合并极化微管相关蛋白Kar9在细胞周期早期确定纺锤体的方向（参考文献7 - 9）。与Kar9结合的Myo2的尾部结构域还与分泌囊泡和液泡成分相互作用，使其成为酵母细胞极化的关键组成部分。
