A briefe history of the cell cycle

1. 18xx Interphase-Mitosis 1951 Discovery of a distinct S-phase 1970 Cell fusion experiments 1971 Discovery of MPF 197x Yeast cdc mutants 1983 Discovery of the first cyclins 1988 Cyclin B+cdc2 = MPF 199x Ubiquitin and the cell cycle 1999 Sister chromatid separation A briefe history of the cell cycle

2. The most important role of cell cycle control is to ensure accurate chromosome segregation M G2 G1 S

3. General principles and methods G1 - To cycle or not to cycle S- Replicating the genome M-Segregating the genome Cytokinesis - Making two cells

4. ONCE and ONLY ONCE

5. Rao and Johnson 1970

6. Fluorescent Activated Cell Scan/Sorter (FACS)

7. A typical FACS analysis

8. Methods for cell synchronisation

9. Model organisms I - Budding yeast (S.cerevisiae) L. Hartwell

10. Model organisms II - Fission yeast (S.pombe) P. Nurse

11. Identification of cell cycle ts mutants

13. Generation of temperature sensitive budding yeast mutants

14. Analysis of ts cell cycle mutants S M M M G1 M

15. Maturation promoting factor

17. Oscillations of MPF

21. MPF = cdc2 + cyclin B

22. Cln1,2,3 G1 Cyclins and cyclin dependent kinases (cdks) - in Budding yeast Clb5,6 Cdk1 (cdc28) (S.p. cdc2) S G2 Clb3,4 M Clb1,2

23. G1 Cyclin D1,2,3 Cyclin E Cyclin A S Cyclin A Cyclin B1,2,3 M Cyclins and cyclin dependent kinases (cdks) - in multi-cellular organisms Cdk4,6 Cdk2 Cdk1 (S.p. cdc2)

24. Cdc2/28 (=cdk1) is regulated by: 1. Binding of a cyclin2. Inhibitory phosphorylation3. Activating phosophorylation4. Binding of CKI5. Cellular localization

27. G1 - To cycle or not to cycle S- Replicating the genome M-Segregating the genome Cytokinesis - Making two cells

30. E2F P E2F P E2F E2F E2F P E2F E2F E2F P G1 Cyc D cdk4 S P pRB Cyc E cdk2

32. G1 - To cycle or not to cycle S- Replicating the genome M-Segregating the genome Cytokinesis - Making two cells

33. The human genome is encoded by 3,000,000,000 bp (3x109) which must all be replicated within a few hours with the highest fidelity. The loss of a bp is irreversible and a single mistake could potentially lead to the death of the organism.

34. Analogy One page contains about 3000 letters. Imagine that you have to copy one million pages in a few hours and have to bind them into 23 volumes. You can use as many typist as you like but you are allowed no mistakes -no missing letter, no letter twice, and no substitutions.

37. G1 - To cycle or not to cycle S- Replicating the genome M-Segregating the genome Cytokinesis - Making two cells

40. The story of the two blind men • Two blind men go into a shop and buy each five different pairs of socks. Unfortunately all ten pairs were packed in the same bag. • How can the two men separate the socks so that each of them will get five pairs ?

41. The three factors that enable sister chromatid separation • The glue - cohesins • The pulling force - the mitotic spindle • The timing mechanism - spindle checkpoint

42. The three factors that enable sister chromatid separation • The glue - cohesins • The pulling force - the mitotic spindle • The timing mechanism - spindle checkpoint

44. Check Separase Check APC Separase Separase Separase point Securin Securin point Cohesin Cohesin prometaphase metaphase anaphase Sister chromatid separation from prometaphase to anaphase APC Ub Ub Ub Securin

45. Non-degradable securin does not prevent cytokinesis but interferes with complete chromatide separation histon-GFP Hoechst NIH3T3 HeLa securin securin KAA-DM securin KAA-DM

46. The three factors that enable sister chromatid separation • The glue - cohesins • The pulling force - the mitotic spindle • The timing mechanism - spindle checkpoint