The checkpoint delaying anaphase in response to chromosome monoorientation is mediated by an inhibitory signal produced by unattached kinetochores.
The checkpoint delaying anaphase in response to chromosome monoorientation is mediated by an inhibitory signal produced by unattached kinetochores.
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响应染色体单向化的检查点延迟后期是由未连接的动物学产生的抑制信号介导的。
DOI：
10.1083/jcb.130.4.941
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发表时间：
1995-08
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;COLE, RW;KHODJAKOV, A;SLUDER, G
在 Ptk1 细胞的有丝分裂过程中，平均直到最后一条单向染色体获得与纺锤体的双极附着后 23 +/- 1 分钟，后期才开始——这一事件可能需要 3 小时（Rieder, C. L., A. Schultz, R. W. Cole, and G. Sluder. 1994. J. Cell Biol. 127:1301-1310）。为了确定这种细胞周期检查点信号的性质及其产生位点，我们在激光照射破坏特定染色体区域之前和之后通过视频显微镜跟踪 PtK1 细胞。最后一条单向染色体上的着丝粒（及其两个相关的姐妹动粒）被破坏后 17 +/- 1 分钟，检查点解除，细胞进入后期。因此，检查点机制监测单向染色体着丝粒中产生的后期抑制剂。接下来，在存在一条单向染色体的情况下，我们破坏了双向染色体上的一个着丝粒，以创建第二条缺乏独立着丝粒的单向染色体。在此条件下，在未照射的单向染色体双取向后24+/-1.5分钟，在实验产生的单向染色体存在的情况下，后期开始。该结果表明检查点信号不是由单向染色体的附着着丝粒或整个着丝粒体积产生的。最后，我们选择性地破坏了最后一条单向染色体上未附着的着丝粒。在此条件下，细胞在手术后 20 +/- 2.5 分钟进入后期，没有聚集到被照射的染色体上。这些细胞在后期的相关光学显微镜/电子显微镜证实了未附着的染色单体上不存在动粒。总之，我们的数据表明，单向 PtK1 染色体的独立着丝粒内或附近的分子会抑制中期 - 后期转变。
During mitosis in Ptk1 cells anaphase is not initiated until, on average, 23 +/- 1 min after the last monooriented chromosome acquires a bipolar attachment to the spindle--an event that may require 3 h (Rieder, C. L., A. Schultz, R. W. Cole, and G. Sluder. 1994. J. Cell Biol. 127:1301-1310). To determine the nature of this cell-cycle checkpoint signal, and its site of production, we followed PtK1 cells by video microscopy prior to and after destroying specific chromosomal regions by laser irradiation. The checkpoint was relieved, and cells entered anaphase, 17 +/- 1 min after the centromere (and both of its associated sister kinetochores) was destroyed on the last monooriented chromosome. Thus, the checkpoint mechanism monitors an inhibitor of anaphase produced in the centromere of monooriented chromosomes. Next, in the presence of one monooriented chromosome, we destroyed one kinetochore on a bioriented chromosome to create a second monooriented chromosome lacking an unattached kinetochore. Under this condition anaphase began in the presence of the experimentally created monooriented chromosome 24 +/- 1.5 min after the nonirradiated monooriented chromosome bioriented. This result reveals that the checkpoint signal is not generated by the attached kinetochore of a monooriented chromosome or throughout the centromere volume. Finally, we selectively destroyed the unattached kinetochore on the last monooriented chromosome. Under this condition cells entered anaphase 20 +/- 2.5 min after the operation, without congressing the irradiated chromosome. Correlative light microscopy/elctron microscopy of these cells in anaphase confirmed the absence of a kinetochore on the unattached chromatid. Together, our data reveal that molecules in or near the unattached kinetochore of a monooriented PtK1 chromosome inhibit the metaphase-anaphase transition.
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DOI：
10.1002/jemt.1060090406
发表时间：
1988-08-01
期刊：
JOURNAL OF ELECTRON MICROSCOPY TECHNIQUE
影响因子：
--
作者：
MARKO, M;LEITH, A;PARSONS, D
通讯作者：
PARSONS, D
DOI：
10.1083/jcb.88.3.543
发表时间：
1981-03
期刊：
The Journal of cell biology
影响因子：
--
作者：
McNeill PA;Berns MW
通讯作者：
Berns MW
影响因子：
7.5
作者：
MURRAY, A
通讯作者：
MURRAY, A
影响因子：
7.8
作者：
RIEDER, CL;SCHULTZ, A;SLUDER, G
通讯作者：
SLUDER, G
影响因子：
1.6
作者：
ROOS, UP
通讯作者：
ROOS, UP