Centralspindlin regulates ECT2 and RhoA accumulation at the equatorial cortex during cytokinesis
Centralspindlin regulates ECT2 and RhoA accumulation at the equatorial cortex during cytokinesis
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DOI：
10.1242/jcs.02737
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发表时间：
2006-01-01
影响因子：
4
通讯作者：
Yonemura, S
中科院分区：
文献类型：
--
作者：
Nishimura, Y;Yonemura, S
在确定细胞分裂平面的过程中，由来自有丝分裂器的信号在赤道细胞皮质处诱导肌动球蛋白收缩环，并收缩以引起卵裂沟进展。虽然已知小的GTdR RhoA可能通过控制肌动蛋白丝组装和增强肌动球蛋白相互作用来调节进展，但RhoA在分裂平面确定中的任何参与都是未知的。在这项研究中，使用三氯乙酸（TCA）固定协议，我们最近开发的，我们表明，RhoA积累在赤道皮层沟开始之前，并继续集中在分裂沟胞质分裂过程中。我们还表明，Rho活性和微管组织所需的RhoA本地化和适当的开沟。微管组织的选择性破坏表明，星形和中央纺锤体微管可以招募RhoA在赤道皮质。我们发现centralspindlin和ECT2是RhoA定位和开沟所必需的。Centralspindlin定位于中央纺锤体微管和赤道皮质附近的星形微管的尖端，并招募ECT2。从微管的分裂平面确定的位置信息被传递到细胞皮层，通过涉及这些蛋白质的机制来组织肌动蛋白细胞骨架。
During determination of the cell division plane, an actomyosin contractile ring is induced at the equatorial cell cortex by signals from the mitotic apparatus and contracts to cause cleavage furrow progression. Although the small GTPase RhoA is known to regulate the progression, probably by controlling actin filament assembly and enhancing actomyosin interaction, any involvement of RhoA in division plane determination is unknown. In this study, using a trichloroacetic acid (TCA) fixation protocol we recently developed, we show that RhoA accumulates at the equatorial cortex before furrow initiation and continues to concentrate at the cleavage furrow during cytokinesis. We also demonstrate that both Rho activity and microtubule organization are required for RhoA localization and proper furrowing. Selective disruption of microtubule organization revealed that both astral and central spindle microtubules can recruit RhoA at the equatorial cortex. We find that centralspindlin and ECT2 are required for RhoA localization and furrowing. Centralspindlin is localized both to central spindle microtubules and at the tips of astral microtubules near the equatorial cortex and recruits ECT2. Positional information for division plane determination from microtubules is transmitted to the cell cortex to organize actin cytoskeleton through a mechanism involving these proteins.