Research Interplay between microtubule polymerases, γ-tubulin complexes and their receptors

The faithful separation of chromosomes during cell division requires the de novo formation of microtubules in the correct place and time to form the mitotic spindle. The γ-ring tubulin complex (γ-TuRC) serves as a template for the nucleation of microtubules, but its assembly, subcellular localization and conformational activation require interaction with other factors, such as conserved receptor proteins and microtubule polymerases. In a collaboration between the groups of Elmar Schiebel, Matthias Mayer and Stefan Pfeffer (all ZMBH), the shared first authors Anjun Zheng, Bram Vermeulen and Martin Würtz used a combination of cryo-electron microscopy, biochemistry, cell biology and hydrogen-exchange mass-spectrometry to study the assembly and activation of the γ-TuRC from the yeast Candida albicans. Their work reveals how the receptor protein Spc72 assembles the γ-TuRC into a microtubule template conformationally primed for nucleation and sheds light on how the microtubule polymerase Stu2 is recruited to the complex to promote microtubule formation.