Dynamic Instability of Microtubules Is Regulated by Force

• Published in: The Journal of cell biology 2003-06, Vol.161 (6), p.1029-1034
• Main Authors: Janson, Marcel E., de Dood, Mathilde E., Dogterom, Marileen
• Format: Article
• Language: English
• Subjects: Animal cells; Animals; Arithmetic mean; Average velocity; Buckling; Cattle; Cell Cycle - physiology; Cells; Disasters; Eukaryotic Cells - metabolism; Microbiology; Microscopy; Microtubule-Associated Proteins - metabolism; Microtubules; Microtubules - metabolism; Nucleation; Polymerization; Proteins; Reaction Time - physiology; Somatic cells; Tensile Strength; Tubulin - metabolism
• ISSN: 0021-9525; 1540-8140
• DOI: 10.1083/jcb.200301147

Microtubules are long filamentous protein structures that randomly alternate between periods of elongation and shortening in a process termed dynamic instability. The average time a microtubule spends in an elongation phase, known as the catastrophe time, is regulated by the biochemical machinery of the cell throughout the cell cycle. In this light, observed changes in the catastrophe time near cellular boundaries may be attributed to regulatory effects of localized proteins. Here, we argue that the pushing force generated by a microtubule when growing against a cellular object may itself provide a regulatory mechanism of the catastrophe time. We observed an up to 20-fold, force-dependent decrease in the catastrophe time when microtubules grown from purified tubulin were polymerizing against microfabricated barriers. Comparison with catastrophe times for microtubules growing freely at different tubulin concentrations leads us to conclude that force reduces the catastrophe time only by limiting the rate of tubulin addition.