Cell cycle and cell programmed death

1. Cell cycle and cell programmed death Haixu Tang School of Informatics

2. The cell cycle

3. The events of eucaryotic cell division

4. The phases of the cell cycle

5. A comparison of the cell cycles of fission yeasts and budding yeasts

6. The behavior of a temperature-sensitive cdc mutant

7. The Cell-Cycle Control System Can Be Analyzed Biochemically in Animal Embryos

8. The Cell-Cycle Control System of Mammals Can Be Studied in Culture

9. Labeling S-phase cells

10. FACS: fluorescence-activated cell sorter

11. The control of the cell cycle

12. Basic control system • A clock, or timer, that turns on each event at a specific time, thus providing a fixed amount of time for the completion of each event. • A mechanism for initiating events in the correct order; entry into mitosis, for example, must always come after DNA replication. • A mechanism to ensure that each event is triggered only once per cycle. • Binary (on/off) switches that trigger events in a complete, irreversible fashion. It would clearly be disastrous, for example, if events like chromosome condensation or nuclear envelope breakdown were initiated but not completed. • Robustness: backup mechanisms to ensure that the cycle can work properly even when parts of the system malfunction. • Adaptability, so that the system's behavior can be modified to suit specific cell types or environmental conditions.

13. The Control System Can Arrest the Cell Cycle at Specific Checkpoints

14. Checkpoints Generally Operate Through Negative Intracellular Signals • The Cell-Cycle Control System Is Based on Cyclically Activated Protein Kinases • Cdk Activity Can Be Suppressed Both by Inhibitory Phosphorylation and by Inhibitory Proteins • The Cell-Cycle Control System Depends on Cyclical Proteolysis • Cell-Cycle Control Also Depends on Transcriptional Regulation

15. Two key components of the cell-cycle control system • G1/S-cyclins bind Cdks at the end of G1 and commit the cell to DNA replication. • S-cyclins bind Cdks during S phase and are required for the initiation of DNA replication. • M-cyclins promote the events of mitosis. • G1-cyclins, helps promote passage through Start or the restriction point in late G1.

16. Core of the cell-cycle control system

17. The structural basis of Cdk activation

18. The regulation of Cdk activity

19. The inhibition of a cyclin-Cdk complex by a CKI

20. The control of proteolysis

21. Rereplication block.

22. The initiation of DNA replication once per cell cycle

23. The activation of M-Cdk

24. The triggering of sister-chromatid separation by the APC

25. The creation of a G1 phase

26. The control of G1 progression

27. How DNA damage arrests the cell cycle?

28. An overview of the cell-cycle control system

29. Cell death

30. The caspase cascade involved in apoptosis

31. Intracellular Regulators of the Cell Death Program • The Bcl-2 family • IAP (inhibitor of apoptosis) family

32. Induction of apoptosis by either extracellular or intracellular stimuli

33. The extracellular signal molecules • Mitogens, which stimulate cell division, primarily by relieving intracellular negative controls that otherwise block progress through the cell cycle. • Growth factors, which stimulate cell growth (an increase in cell mass) by promoting the synthesis of proteins and other macromolecules and by inhibiting their degradation. • Survival factors, which promote cell survival by suppressing apoptosis