Fig. 7. NOXA contributes to mitotic apoptosis by regulating MCL1–BAX.

A Mitotic apoptosis in MARCH5^KO NOXA^KO is both BAX- and BAK-dependent. BAX^KO or BAK^KO was generated from MARCH5^KO NOXA^KO cells. The cells were synchronized and arrested in mitosis as before. Protein expression was analyzed with immunoblotting. B BAX-dependent mitotic apoptosis in MARCH5^KO NOXA^KO is mediated by MCL1. BAX^KO or BAK^KO was generated from MARCH5^KO NOXA^KO MCL1^KO cells expressing ^mAIDMCL1. The cells were synchronized and arrested in mitosis as before. ^mAIDMCL1 was turned off with DI at the time of second thymidine release. Protein expression was analyzed with immunoblotting. C Disruption of BAK delayed mitotic apoptosis in MARCH5^KO NOXA^KO MCL1^KO cells. Cells were synchronized and treated as in B (except that they were transiently transfected with histone H2B-GFP before synchronization). The cells were incubated with DI to turn off ^mAIDMCL1 before individual cells were tracked using live-cell imaging. The duration of mitotic arrest is plotted using Kaplan–Meier estimator. Box-and-whisker plots show the elapsed time between mitotic entry and mitotic apoptosis/slippage. **p < 0.01.