Graduate School of Engineering, Osaka University, Suita, Japan.
Faculty of Agriculture, Kyushu University, Fukuoka, Japan.
Elife. 2017 Aug 30;6:e24340. doi: 10.7554/eLife.24340.
Cytoplasmic microtubules (cMT) control mitotic spindle positioning in many organisms, and are therefore pivotal for successful cell division. Despite its importance, the temporal control of cMT formation remains poorly understood. Here we show that unlike the best-studied yeast , position of pre-anaphase nucleus is not strongly biased toward bud neck in and the regulation of spindle positioning becomes active only shortly before anaphase. This is likely due to the unstable property of cMTs compared to those in . Furthermore, we show that cMT nucleation/anchoring is restricted at the level of recruitment of the γ-tubulin complex receptor, Spc72, to spindle pole body (SPB), which is regulated by the polo-like kinase Cdc5. Additionally, electron microscopy revealed that the cytoplasmic side of SPB is structurally different between G1 and anaphase. Thus, polo-like kinase dependent recruitment of γ-tubulin receptor to SPBs determines the timing of spindle orientation in
细胞质微管（cMT）控制着许多生物的有丝分裂纺锤体的定位，因此对于成功的细胞分裂至关重要。尽管它很重要，但 cMT 形成的时间控制仍然知之甚少。在这里，我们表明与研究最充分的酵母不同，核前期的位置在 中并没有强烈偏向芽颈，并且纺锤体定位的调节只有在后期开始前很短的时间才会活跃。这可能是由于 cMT 与 中那些相比的不稳定性。此外，我们还表明，cMT 的成核/锚定受到 γ-微管蛋白复合物受体 Spc72 向纺锤体极体（SPB）募集的限制，这受 polo 样激酶 Cdc5 的调节。此外，电子显微镜显示，G1 和后期之间 SPB 的细胞质侧在结构上有所不同。因此，polo 样激酶依赖性 γ-微管蛋白受体到 SPB 的募集决定了纺锤体在中的取向时间
