Spatial Control of Cytokinesis by Cdr2 Kinase and Mid1/Anillin Nuclear Export
Spatial Control of Cytokinesis by Cdr2 Kinase and Mid1/Anillin Nuclear Export
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DOI：
10.1016/j.cub.2009.04.024
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发表时间：
2009-06-09
期刊：
影响因子：
9.2
通讯作者：
Paoletti, Anne
中科院分区：
文献类型：
--
作者：
Almonacid, Maria;Moseley, James B.;Paoletti, Anne
维持基因组的完整性和细胞功能需要细胞分裂平面的适当定位。在大多数真核生物中，胞质分裂依赖于一个收缩的肌球蛋白环，该环由固有的空间信号定位，而这些信号在分子水平上定义得很差。分裂酵母细胞在细胞中心的核[1，2]发出的正的空间信号和细胞尖端的负的空间信号[3，4]的响应下组装一个中间收缩环。这些信号控制着苯丙素样蛋白MID1的定位，它定义了内侧皮质的分裂平面的位置，在有丝分裂开始时它在那里招募收缩环组件[5-10]。在这里，我们展示了Cdr2激酶通过与MID1的N端结合，在间期将MID1锚定在内侧皮质。这种联系是细胞尖端对MID1分布的负调控的基础。我们还证明了来自细胞核的阳性信号是基于MID1核输出的，在有丝分裂早期，MID1核输出将分裂平面位置与核位置联系起来。在核移位后，MID1的核输出主导于依赖Cdr2的MID1的定位。我们得出结论，依赖于Cdr2和核出口的MID1定位构成了两种重叠的机制，传递细胞极性和核位置信息，以确保适当的划分平面规范。
Maintaining genome integrity and cellular function requires proper positioning of the cell division plane. In most eukaryotes, cytokinesis relies on a contractile actomyosin ring positioned by intrinsic spatial signals that are poorly defined at the molecular level. Fission yeast cells assemble a medial contractile ring in response to positive spatial cues from the nucleus at the cell center [1, 2] and negative spatial cues from the cell tips [3, 4]. These signals control the localization of the anillin-like protein Mid1, which defines the position of the division plane at the medial cortex, where it recruits contractile-ring components at mitosis onset [5-10]. Here we show that Cdr2 kinase anchors Mid1 at the medial cortex during interphase through association with the Mid1 N terminus. This association underlies the negative regulation of Mid1 distribution by cell tips. We also demonstrate that the positive signaling from the nucleus is based on Mid1 nuclear export, which links division-plane position to nuclear position during early mitosis. After nuclear displacement, Mid1 nuclear export is dominant over Cdr2-dependent positioning of Mid1. We conclude that Cdr2- and nuclear export-dependent positioning of Mid1 constitute two overlapping mechanisms that relay cell polarity and nuclear positional information to ensure proper division-plane specification.