ANAPHASE ONSET IN VERTEBRATE SOMATIC-CELLS IS CONTROLLED BY A CHECKPOINT THAT MONITORS SISTER KINETOCHORE ATTACHMENT TO THE SPINDLE
ANAPHASE ONSET IN VERTEBRATE SOMATIC-CELLS IS CONTROLLED BY A CHECKPOINT THAT MONITORS SISTER KINETOCHORE ATTACHMENT TO THE SPINDLE
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DOI：
10.1083/jcb.127.5.1301
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发表时间：
1994-12-01
影响因子：
7.8
通讯作者：
SLUDER, G
中科院分区：
文献类型：
--
作者：
RIEDER, CL;SCHULTZ, A;SLUDER, G
为了测试流行但未经证实的假设，即脊椎动物体细胞中的中期-后期转换受到监测染色体的检查点（即，动粒）附着在纺锤体上，我们拍摄了126个PtK 1细胞的有丝分裂。我们发现，从核膜破裂到后期开始的时间与鳗鱼具有未附着动粒的时间呈线性相关（r（2）= 0.85），即使单个未附着动粒也会延迟后期开始。我们还发现，后期开始在一个相对恒定的平均间隔23分钟后，最后一个着丝粒重视，无论多久的细胞拥有独立的着丝粒。从这些结果中，我们得出结论，脊椎动物体细胞具有中期后期检查点控制，监测姐妹动粒附件的纺锤体。我们还发现，用0.3-0.75 nM紫杉醇处理的一些细胞，在最后一个动粒附着在纺锤体上后，进入后期，并在处理后3小时内完成正常的向极染色体运动（后期A）-远远超过未处理细胞所表现出的9-48分钟范围。事实上，纺锤体双极性和中期排列的动粒在这些细胞中保持，并在后期染色体向极移动，表明检查点监测的不仅仅是微管在姐妹动粒或中期排列的染色体。我们的数据是最一致的假设，即检查点监测的着丝粒和它们相关的微管之间的张力增加的双向发生。
To test the popular but unproven assumption that the metaphase-anaphase transition in vertebrate somatic cells is subject to a checkpoint that monitors chromosome (i.e., kinetochore) attachment to the spindle, we filmed mitosis in 126 PtK1 cells. We found that the time from nuclear envelope breakdown to anaphase onset is linearly related (r(2) = 0.85) to the duration the eel has unattached kinetochores, and that even a single unattached kinetochore delays anaphase onset. We also found that anaphase is initiated at a relatively constant 23-min average interval after the last kinetochore attaches, regardless of how long the cell possessed unattached kinetochores. From these results we conclude that vertebrate somatic cells possess a metaphase-anaphase checkpoint control that monitors sister kinetochore attachment to the spindle. We also found that some cells treated with 0.3-0.75 nM Taxol, after the last kinetochore attached to the spindle, entered anaphase and completed normal poleward chromosome motion (anaphase A) up to 3 h after the treatment-well beyond the 9-48-min range exhibited by untreated cells. The fact that spindle bipolarity and the metaphase alignment of kinetochores are maintained in these cells, and that the chromosomes move poleward during anaphase, suggests that the checkpoint monitors more than just the attachment of microtubules at sister kinetochores or the metaphase alignment of chromosomes. Our data are most consistent with the hypothesis that the checkpoint monitors an increase in tension between kinetochores and their associated microtubules as biorientation occurs.