Dynamics ofCell Division

Sharyn A. Endow

David M. Glover

Plate section falls between pages 222 and 223

List of contributors

xv

Abbreviations

xvi i

1. Cell cycle checkpoints: safe passage through mitosis

1

KRISTIN A R . YU, ROBERT J . DURONJO, AND WILLIAM SULLIVA N

1. Introduction

12. Activation of the mitotic CDK controls entry into mitosis

22.1 Activation of mitotic CDK requires an association with cyclin

32 .2 The APC mediates cyclin degradation and sister chromosome separation

42 .3 Proteins that negatively regulate CDK activity

52 .4 Post-translational phosphorylation regulates mitotic CDK activity

5

3. Cell cycle checkpoints

53.1 Mutational analysis identifies RAD9 as a DNA damage checkpoint

73 .2 Checkpoints monitor many cellular events and involve signa l

transduction pathways that link delays in the cell cycle to repai rprocesses

93 .3 Ambiguities in the concept of cell cycle checkpoints

9

4. Lessons from budding yeast : the role of checkpoints in monitoringthe completion of S phase and DNA damage

1 04.1 Synthetic lethal screens provide an efficient means of identifyin g

additional checkpoint mutations

1 04.2 Detecting DNA damage

1 14.3 Monitoring completion of S phase

1 24.4 Signal transduction

1 34.5 p53 is a mammalian checkpoint gene that functions during G 1 -S

and G 2-M

144.6 The mammalian p53 gene is involved in a spindle assembly checkpoint

1 54 .7 Arresting the cell cycle

1 64 .8 Adaptation releases checkpoint-induced arrest

17

5. The role of checkpoints in monitoring spindle assembly

175.1 Genetic identification of the spindle assembly checkpoint

185.2 Spindle checkpoints monitor the state of the kinetochore

19

5.3 Tension is moni tored by the spindle assembly checkpoint

2 0

5.4 Molecular changes at the kinetochore in response to tension

2 0

5.5 In some cells, free kinetochores rather than tension activate the spindl eassembly checkpoint

2 2

5.6 The MAD and BUB genes are involved in different steps of the spindl eassembly checkpoint

2 2

5.7 MAP kinase is required for the spindle assembly checkpoint in cel lcycle extracts

2 4

5.8 The APC may be the target of the spindle assembly checkpoint

24

6. The role of checkpoints in the initial embryonic cell cycles

24

6.1 Relative timing of mitotic events may be the primary mechanis mmaintaining fidelity of division in early Xenopus embryos

2 6

6.2 Checkpoint control mechanisms are present but not activated in earlyXenopus embryos

2 6

6.3 The syncytial Drosophila nuclear cycles exhibit a number of dependencyrelationshiops

2 7

6 .4 A DNA replication/DNA damage checkpoint may operate during th elate syncytial divisions of Drosophila

2 8

6.5 In the syncytial Drosophila embryo, checkpoints link delays in thecell cycle to nuclear elimination

3 0

7. Future directions

30

References

3 1

A

2. Mitotic changes in the nuclear envelope

42

BRIAN R . MILLER and DOUGLASS J . FORBE S

1. Overview

42

2. The nuclear lamina and membrane

42

2.1 Changes to the nuclear lamina at mitosis

42

2.2 Lamin-associated proteins

44

2.3 Regulation of nuclear membrane dynamics by phosphorylation

44

2.4 Disassembly of the lamina and nuclear membrane

45

3. Nuclear pore complexes

46

4. Reassembly of the nuclear envelope

47

5. Nuclear pore assembly

50

6. Future directions

53

References

54

3. Poles apart? Spindle pole bodies and centrosome sdiffer in ultrastructure yet their function an dregulation are conserved

57

IAIN M. HAGAN, KEITH GULL, and DAVID M . GLOVER

1. Introduction

57

2. Ultrastructure of the spindle poles

58

2.1 The spindle pole bodies of fungi

58

2.2 Animal cell centrosomes

62

3. Components of polar MTOCs and their function

66

3.1 The gammasome

66

3.2 Units of self-assembly in the budding yeast SPB

70

3.3 Yeast SPB components identified through genetic screening

74

3.4 Components of the SPB in S . pombe

75

3.5 Components of animal cell centrosomes

75

4. Duplication cycles

77

4.1 SPB duplication and separation in S . cerevisiae

77

4.2 The centrosome cycle : maturation of the centriole

79

4.3 Co-ordination of the centrosome cycle with the cell cycle

80

4.4 Centrosome separation

82

5. Conclusions and perspectives

85

Acknowledgements

86

References

86

4. Microtubule dynamics, molecular motors, an dchromosome behavior

9 7

ISABELLE VERNOS and ERIC KARSENT I

1. Introduction

9 7

2. Microtubule dynamics during the cell cycle

9 8

2 .1 Microtubule dynamics in vitro

9 9

2 .2 Microtubule dynamics in vivo

10 1

2 .3 Regulation of microtubule dynamics during the cell cycle

10 1

3. Chromosome movements during mitosis

10 3

3.1 Microtubule dynamics at kinetochores and chromosome movements

10 6

3.2 The role of chromosome arms in chromosome movements

108

4. Role of kinetochores and chromosome arms in spindle assembly

1104.1 Role of kinetochores in spindle assembly

1104.2 Role of chromosome arms in spindle assembly

11 14.3 Molecular basis of the effect of chromosome arms on spindle assembly

112

5. The importance of motor localizations in spindle assembly an dfunction

1145.1 Targeting by stereospecific interactions

11 55.2 Control of targeting by phosphorylation

11 56. Conclusion

117

References

11 8

5. A moveable feast : the centromere-kinetochor ecomplex in cell division

:124

KEVIN F . SULLIVA N

1. Introduction

124

2. Centromere structure

1252 .1 S . cerevisiae

12 62 .2 S . pombe

12 92.3 Metazoan centromeres

13 22.4 Centromere proteins

13 62.5 Chromatin structure and the epigenetic centromere

14 0

3. Microtubule binding and motor function

1423.1 A multitude of motors

14 23.2 Kinetochores and microtubule dynamics

1453.3 What is the primary kinetochore-microtubule contact?

1464. Chromatid cohesion

14 74.1 DNA topoisomerase II

14 74.2 Centromeric cohesion proteins

14 84.3 Proteolysis and chromatin cohesion

14 9

5. Regulatory properties of centrorneres

14 95.1 Mechanoregulation by kinetochores

14 95.2 Kinetochore structure as a process

150

6. Conclusions and perspectives

15 1

Acknowledgements

152

References

152

6. Telomeres: structure, synthesis, and cell cycl eregulation

164

TIMOTHY R . HUGHES and VICTORIA LUNDBLA D

1. Introduction

164

2. Telomerase

1652.1 The RNA subunit of telomerase

1662.2 Protein subunits of telomerase

1692.3 Telomerase biochemistry

172

3. Coordination of telomere replication with semi-conservativ eDNA replication

1763.1 The consequence of leading and lagging strand DNA synthesis fo r

linear chromosomes

17 73 .2 Is telomerase action coordinated with the primary replication

machinery?

180

4. Telomeric chromatin and telomere-binding proteins

1824.1 Proteins that bind double-stranded telomeric DNA

1834.2 The yeast Rap1 protein recruits a silencing complex

1854.3 Proteins that bind single-stranded telomeric DNA

1864.4 Regulation of telomeric proteins

1884.5 Other proteins that act at the telomere

189

5. Telomeres and telomerase regulation in mammals : the telomer ehypotheses of cancer and aging

189

6. Alternative pathways for telomere maintenance

19 1

7. Future perspectives

192

References

193

7. Meiosis: chromosome behavior and spindle dynamics 203

GARY H . KARPEN and SHARYN A. ENDOW

1. General features of meiosis

203

2. Chromosome pairing, synapsis, and movement

2062 .1 Homolog synapsis and disjunction

2062.2 Non-recombinant chromosomes disjoin normally in meiosis I

2102.3 Chromosome segregation in meiosis

218

3. Spindle assembly and dynamics

2223.1 Meiotic spindle structure

222

3.2 Assembly of a bipolar meiotic spindle

2233.3 Meiotic spindle dynamics

2303.4 Cell cycle regulation of the meiotic divisions

2324. Conclusions and future prospects

235

Acknowledgements

236References

236

8. Inheritance of the cytoplasm during cell division

248

DAVID T . SHIMA and GRAHAM WARRE N

1. Introduction

248

2. Defining inheritance

2483. Biogenesis

2503.1 Clues from disassembly/reassembly of the Golgi apparatus

25 13 .2 Growth and division of the Golgi stack

2543.3 Templated growth: the budding yeast vacuole

2564. Partitioning of the cytoplasm

2574.1 Ultrastructural view of Golgi partitioning

2594.2 Cell-free systems

2594.3 Analysis of Golgi partitioning using green fluorescent protein

26 14.4 Semi-ordered partitioning

263

5. Conclusions and future directions

263References

264

9. Cytokinesis

270

MICHAEL L . GOLDBERG, KRISTIN C . GUNSALUS, ROGER E . KARESS, an d

FRED CHAN G

1. Introduction

2702. How do cells know where to place the cleavage furrow?

2702.1 Cleavage site determination in animal cells

2702.2 Division site determination in Schizosaccharomyces pombe

276

2.3 Division site determination in S . cerevisiae

279

2.4 Is a unified view of the control of contractile ring location possible?

2813. How do cells know when to begin cleavage?

28 23.1 When is the signal transmitted?

28 23.2 Cytokinesis and cell cycle controls

283

4. What events link cytokinetic initiation signals with elaboration o fthe contractile ring?

2864 .1 Calcium in cytokinetic signal transduction

28 74 .2 The role of Rho-family G proteins in cytokinesis

2875. How is the contractile ring assembled and how does it function?

2925.1 Actin at the cleavage furrow

2935.2 The role of myosin in cytokinesis

2975.3 The role of septins in cytokinesis

3025.4 Other cytoskeletal proteins at the cleavage furrow

3045.5 Processes related to cytokinesis

3046. What do we still need to learn about cytokinesis?

305

References

306

Index

317