Thomas Surrey – Centre de Regulació Genòmica (CRG)
Microtubules are tube-like protein polymers that are essential for correct intracellular organization and for cell division. The number of microtubules needs to be precisely controlled and this is done by a protein complex that is thought to serve as a template for microtubule growth. We have developed a fluorescence microscopy-based assay allowing us to observe new microtubule formation from single templates. We found that the isolated templating complex is surprisingly inefficient in starting microtubule growth. Cryo-electron microsopy allowed then to obtain the structure of the complex at high resolution which revealed a mismatch between template and microtubule. This suggest that a shape change of the template is required to activate it and that in living cells template-binding proteins may induce this chance controlling the formation of new microtubules.