Table III. Effect of stress kinases and cyclin A–Cdk kinases on the antephase checkpoint.
| Protein injected | Return to interphase |
Continue to mitosis |
Arrest in prophase |
|---|---|---|---|
| GST-p38α | 6 | 1 | 0 |
| p38α | 6 | 3 | 0 |
| p38β | 7 | 2 | 1 |
| p38δ | 1 | 5 | 4 |
| Cyclin A–CDK2AF | 0 | 9 | 4 |
| Cyclin A–CDK2 | 7 | 4 | 3 |
PtK1 cells were injected with the proteins as described and their behavior was assayed by time-lapse DIC microscopy. Cells that decondensed their chromosomes were scored as returning to interphase, and cells that broke down their nuclear envelopes were scored as continuing to mitosis.