Interplay Between Spindle Architecture and Function - International Review of Cell and Molecular Biology - page 82

CHAPTER THREE

Interplay Between Spindle
Architecture and Function

Kara J. Helmke, Rebecca Heald 1 , Jeremy D. Wilbur 1
Department of Molecular and Cell Biology, University of California, Berkeley, California, USA
1 Corresponding authors: e-mail address: [e-mail]; [e-mail]

Contents
1. Introduction 84

2. Conserved Features of the Metaphase Spindle 85

2.1 Microtubules and their dynamics 85

2.2 Spindle bipolarity 86

2.3 Microtubule populations within the spindle 87

2.4 Microtubule dynamics and organization in the spindle 90

3. Nucleation and Origin of Microtubules in the Spindle 93

3.1 Centrosome-mediated search-and-capture 94

3.2 Mitotic chromatin-mediated nucleation 96

3.3 Kinetochore-driven nucleation 98

3.4 Microtubule-branching nucleation 99

4. Molecular Mechanisms Defining Spindle Architecture: Microtubule Stability and
Transport

101

4.1 Microtubule-stabilizing proteins 101

4.2 Microtubule-destabilizing proteins 103

4.3 Motor proteins and microtubule transport 104

5. Variations on a Theme: Tailoring Spindle Architecture 106

5.1 Spindle features and phylogeny 108

5.2 Spindle size 110

5.3 Spindle architecture and compartmentalization 112

5.4 Simulations of microtubule arrangement in the spindle 115

5.5 Future prospects for determining spindle architecture 117

6. Conclusions 118

Acknowledgments 119

References 119

Abstract
The mitotic spindle performs the universal and crucial function of segregating chromo-
somes to daughter cells, and all spindles share common characteristics that facilitate this
task. The spindle is built from microtubule (MT) polymers and hundreds of associated
factors that assemble into a dynamic steady-state structure that is tuned to the