Recruitment of Mad1 to metaphase kinetochores is sufficient to reactivate the mitotic checkpoint.
Recruitment of Mad1 to metaphase kinetochores is sufficient to reactivate the mitotic checkpoint.
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DOI：
10.1083/jcb.201311113
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发表时间：
2014-03-17
期刊：
影响因子：
--
通讯作者：
Lampson MA
中科院分区：
文献类型：
--
作者：
Ballister ER;Riegman M;Lampson MA
MAD1招募到中期动点重新激活有丝分裂检查点，这不仅需要MAD1的MAD2结合域，还需要MAD1的C端。有丝分裂检查点监控着动粒-微管的附着，并防止后期，直到所有的动粒稳定附着。检查点的调节依赖于检查点蛋白对动点的动态定位。独立的、检查点激活的动点蛋白积累了多个检查点蛋白，一旦稳定连接，这些蛋白就会从动点蛋白中耗尽，从而允许检查点沉默。由于多个蛋白质同时被招募到独立的动点，目前尚不清楚动点上的哪些变化是后期促进复合体/环体(APC/C)抑制所必需的。使用化学诱导的二聚化来操纵具有时间控制的蛋白质定位，我们证明了将检查点蛋白Mad1重新招募到中期动点足以重新激活检查点，而不会伴随着Mps1或BubR1动粒水平的增加。此外，MAD2结合是MAD1激活检查点的必要条件，但不是充分条件；还需要一个保守的C-末端基序。我们的检查点再激活实验结果表明，除了将MAD2转化为其活性构象外，MAD1还在动粒形成了更高级别的有丝分裂检查点复合体。
Mad1 recruitment to metaphase kinetochores reactivates the mitotic checkpoint, which requires the C terminus of Mad1 in addition to its Mad2-binding domain. The mitotic checkpoint monitors kinetochore–microtubule attachment and prevents anaphase until all kinetochores are stably attached. Checkpoint regulation hinges on the dynamic localization of checkpoint proteins to kinetochores. Unattached, checkpoint-active kinetochores accumulate multiple checkpoint proteins, which are depleted from kinetochores upon stable attachment, allowing checkpoint silencing. Because multiple proteins are recruited simultaneously to unattached kinetochores, it is not known what changes at kinetochores are essential for anaphase promoting complex/cyclosome (APC/C) inhibition. Using chemically induced dimerization to manipulate protein localization with temporal control, we show that recruiting the checkpoint protein Mad1 to metaphase kinetochores is sufficient to reactivate the checkpoint without a concomitant increase in kinetochore levels of Mps1 or BubR1. Furthermore, Mad2 binding is necessary but not sufficient for Mad1 to activate the checkpoint; a conserved C-terminal motif is also required. The results of our checkpoint reactivation assay suggest that Mad1, in addition to converting Mad2 to its active conformation, scaffolds formation of a higher-order mitotic checkpoint complex at kinetochores.
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DOI：
10.1083/jcb.201003038
发表时间：
2010-10-18
期刊：
The Journal of cell biology
影响因子：
--
作者：
Jelluma N;Dansen TB;Sliedrecht T;Kwiatkowski NP;Kops GJ
通讯作者：
Kops GJ
影响因子：
21.3
作者：
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通讯作者：
Pines, Jonathon
影响因子：
20.3
作者：
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通讯作者：
Savoldo, Barbara
影响因子：
16.2
作者：
Hoeffer, Charles A.;Tang, Wei;Klann, Eric
通讯作者：
Klann, Eric
影响因子：
16.8
作者：
Luo, XL;Tang, ZY;Yu, HT
通讯作者：
Yu, HT