Cell cycle control of septin ring dynamics in the budding yeast
Cell cycle control of septin ring dynamics in the budding yeast
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DOI：
10.1099/00221287-147-6-1437
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发表时间：
2001-06-01
期刊：
影响因子：
2.8
通讯作者：
Nombela, C
中科院分区：
文献类型：
--
作者：
Cid, VJ;Adamiková, L;Nombela, C
间隔蛋白是一种细胞骨架结构，在真核生物中是保守的，在酿酒酵母中是CDC3、CDC10。Cdc11.在整个萌发周期中，CDC12和Shs1/Sep7间隔蛋白以环的形式聚集在一起，标志着细胞运动平面，这种结构参与了形态发生的不同方面，如细胞极性的选择，几丁质合成的定位，芽萌发后从极极到各向同性的芽生长切换，以及隔膜的空间调节。隔蛋白细胞骨架在芽出现之前聚集在芽前部位，在芽生长过程中保留在那里，并在有丝分裂后期复制，最终在细胞分离后消失。利用Septin-GFP融合和延时共聚焦显微镜，我们已经确定在萌芽合子和假菌丝单极同步生长过程中，Septin的动态保持不变。通过特定的细胞周期抑制和细胞周期调控的解除，我们证明了Septin的组装依赖于G1期细胞周期信号，并且小的GTPase CDc42而不是Rho1对这一事件是必不可少的。然而，在芽生长过程中，隔素环形成一个跨越芽颈的结构，不受有丝分裂调节失败的影响，例如DNA修复或纺锤体组装检查点的激活或后期促进复合体(APC)的失活。在细胞周期结束时，环分裂成两个独立的结构取决于蛋白磷酸酶CDC14参与的有丝分裂退出网络的功能。我们的数据支持细胞周期控制机制在调节Septin动态中的作用，以准确地协调酵母整个萌芽过程中的形态发生。
Septins constitute a cytoskeletal structure that is conserved in eukaryotes, In Saccharomyces cerevisiae, the Cdc3, Cdc10. Cdc11. Cdc12 and Shs1/Sep7 septins assemble as a ring that marks the cytokinetic plane throughout the budding cycle, This structure participates in different aspects of morphogenesis, such as selection of cell polarity, localization of chitin synthesis, the switch from hyperpolar to isotropic bud growth after bud emergence and the spatial regulation of septation. The septin cytoskeleton assembles at the pre-bud site before bud emergence, remains there during bud growth and duplicates at late mitosis eventually disappearing alter cell separation. Using a septin-GFP fusion and time-lapse confocal microscopy, we have determined that septin dynamics are maintained in budding zygotes and during unipolar synchronous growth in pseudohyphae. By means of specific cell cycle arrests and deregulation of cell cycle controls we show that septin assembly is dependent on G1 cyclin/Cdc28-mediated cell cycle signals and that the small GTPase Cdc42, but not Rho1, are essential for this event. However, during bud growth, the septin ring shapes a bud-neck-spanning structure that is unaffected by failures in the regulation of mitosis, such as activation of the DNA repair or spindle assembly checkpoints or inactivation of the anaphase-promoting complex (APC). At the end of the cell cycle, the splitting of the ring into two independent structures depends on the function of the mitotic exit network in which the protein phosphatase Cdc14 participates. Our data support a role of cell cycle control mechanisms in the regulation of septin dynamics to accurately coordinate morphogenesis throughout the budding process in yeast.