Genome-wide analysis of nuclear condensation factors during apoptosis

在凋亡执行中，细胞在被其他细胞吞噬之前执行最终过程，例如DNA切割和核凝聚。Earnshaw等开发了一种无细胞系统，使分离的细胞核在体外能像完整细胞一样发生凋亡。我们以前提出核凝聚可以分为三个不同的步骤，第一阶段环，第二阶段项链和第三阶段核崩溃。对单个细胞核的延时成像显示，所有细胞核都可以遵循一个可重复的凝聚程序，这表明存在一个有序的生化途径。我们发现caspase-6活性对于第3阶段核崩溃的必要性。总之，阶段1中的激酶活性、阶段2中的DNA酶活性和阶段3中的半胱天冬酶-6活性对于每个缩合阶段是必需的。

In apoptotic execution, cells perform final processes, such as DNA cleavage and nuclear condensation before engulfment by other cells. The molecular mechanisms for nuclear condensation are still unclear, while upstream cytoplasmic pathways are well characterized.Earnshaw et al. have developed a cell-free system which allows isolated nuclei could undergo apoptosis in vitro as intact cells did. We have previously proposed that nuclear condensation could be classified into three distinct steps, stage 1 ring, stage 2 necklace and stage 3 nuclear collapse. Time-lapse imaging of individual nuclei showed all nuclei could follow a reproducible program of condensation, suggesting the existence of an ordered biochemical pathway. We found the necessity of caspase-6 activity for stage 3 nuclear collapse. In conclusion, kinase activity in stage 1, DNase activity in stage 2, and caspase-6 activity in stage 3, are essential for each condensation stages.