Transition of human γ-tubulin ring complex into a closed conformation during microtubule nucleation
Microtubules are essential for intracellular organization and chromosome segregation. They are nucleated by the γ-tubulin ring complex (γTuRC). However, isolated vertebrate γTuRC adopts an open conformation that deviates from the microtubule structure, raising the question of the nucleation mechanis...
| Autores: | , , , , |
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| Tipo de documento: | artigo |
| Estado: | Versión aceptada para publicación |
| Data de publicação: | 2024 |
| País: | España |
| Recursos: | Universitat Pompeu Fabra |
| Repositório: | Repositorio Digital de la UPF |
| OAI Identifier: | oai:repositori.upf.edu:10230/59109 |
| Acesso em linha: | http://hdl.handle.net/10230/59109 http://dx.doi.org/10.1126/science.adk6160 |
| Access Level: | Acceso aberto |
| Palavra-chave: | Microtúbuls Tubulines |
| Resumo: | Microtubules are essential for intracellular organization and chromosome segregation. They are nucleated by the γ-tubulin ring complex (γTuRC). However, isolated vertebrate γTuRC adopts an open conformation that deviates from the microtubule structure, raising the question of the nucleation mechanism. Here we determine cryo-electron microscopy structures of human γTuRC bound to a nascent microtubule. Structural changes of the complex into a closed conformation ensure that γTuRC templates the 13-protofilament microtubules that exist in human cells. Closure is mediated by a latch that interacts with incorporating tubulin, making it part of the closing mechanism. Further rearrangements involve all γ-tubulin ring complex subunits and the removal of the actin-containing luminal bridge. Our proposed mechanism of microtubule nucleation by human γTuRC relies on large-scale structural changes that are likely the target of regulation in cells. |
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