The polarized partitioning of proteins in cells underlies asymmetric cell division, which is an important driver of development and cellular diversity. The budding yeast Saccharomyces cerevisiae divides asymmetrically, like many other cells, to generate two distinct progeny cells. A well-known example of an asymmetric protein is the transcription factor Ace2, which localizes specifically to the daughter nucleus, where it drives a daughter-specific transcriptional network. We screened a collection of essential genes to analyze the effect of core cellular processes in asymmetric cell division based on Ace2 localization. This screen identified mutations that affect progression through the cell cycle, suggesting that cell cycle delay is sufficient to disrupt Ace2 asymmetry. To test this model, we blocked cells from progressing through mitosis and found that prolonged metaphase delay is sufficient to disrupt Ace2 asymmetry after release, and that Ace2 asymmetry is restored after cytokinesis. We also demonstrate that members of the evolutionarily conserved FACT chromatin-reorganizing complex are required for both asymmetric and cell cycle-regulated localization of Ace2 and for localization of the RAM network components.

中文翻译：

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酵母细胞分裂过程中的不对称转录因子分配需要 FACT 染色质重塑剂和细胞周期进展。


细胞中蛋白质的极化分配是不对称细胞分裂的基础，这是发育和细胞多​​样性的重要驱动力。与许多其他细胞一样，出芽酵母酿酒酵母不对称分裂，产生两个不同的子代细胞。不对称蛋白的一个众所周知的例子是转录因子 Ace2，它特异性定位于子核，驱动子核特异性转录网络。我们筛选了一系列必需基因，以分析基于 Ace2 定位的不对称细胞分裂中核心细胞过程的影响。该筛选确定了影响细胞周期进展的突变，表明细胞周期延迟足以破坏 Ace2 不对称性。为了测试这个模型，我们阻止细胞进行有丝分裂，发现延长的中期延迟足以破坏释放后的 Ace2 不对称性，并且 Ace2 不对称性在胞质分裂后恢复。我们还证明，Ace2 的不对称定位和细胞周期调节定位以及 RAM 网络组件的定位都需要进化保守的 FACT 染色质重组复合体的成员。