Nuclear envelope morphology constrains diffusion and promotes asymmetric protein segregation in closed mitosis
Nuclear envelope morphology constrains diffusion and promotes asymmetric protein segregation in closed mitosis
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DOI：
10.1083/jcb.201112117
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发表时间：
2012-06-25
影响因子：
7.8
通讯作者：
Barral, Yves
中科院分区：
文献类型：
--
作者：
Boettcher, Barbara;Marquez-Lago, Tatiana T.;Barral, Yves
在营养生长期间，酿酒酵母细胞不对称分裂：母细胞出芽产生较小的子细胞。这个女儿不对称地继承了转录因子Ace2，其激活女儿特异性转录程序。在本文中，我们调查何时以及如何建立和维持这种不对称性。我们发现，Ace2的不对称性是在细长的，但不分裂，后期核。在这个阶段，核质是高度区室化的，很少交换观察到母芽之间的核质蛋白。使用光漂白和在硅片建模，我们表明，扩散障碍划分核膜。相反，核质中蛋白质的行为很好地解释了后期核的哑铃形状。这种区室化的核质促进Ace2不对称后期核。因此，我们的数据表明，酵母细胞使用封闭的有丝分裂的过程和与之相关的形态学限制不对称地分离核质成分。
During vegetative growth, Saccharomyces cerevisiae cells divide asymmetrically: the mother cell buds to produce a smaller daughter cell. This daughter asymmetrically inherits the transcription factor Ace2, which activates daughter-specific transcriptional programs. In this paper, we investigate when and how this asymmetry is established and maintained. We show that Ace2 asymmetry is initiated in the elongated, but undivided, anaphase nucleus. At this stage, the nucleoplasm was highly compartmentalized; little exchange was observed for nucleoplasmic proteins between mother and bud. Using photobleaching and in silico modeling, we show that diffusion barriers compartmentalize the nuclear membranes. In contrast, the behavior of proteins in the nucleoplasm is well explained by the dumbbell shape of the anaphase nucleus. This compartmentalization of the nucleoplasm promoted Ace2 asymmetry in anaphase nuclei. Thus, our data indicate that yeast cells use the process of closed mitosis and the morphological constraints associated with it to asymmetrically segregate nucleoplasmic components.