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...

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Detalles Bibliográficos
Autores: Brito, Cláudia, Serna, Marina, Guerra, Pablo, Llorca, Óscar, Surrey, Thomas
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2024
País:España
Institución:Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)
Repositorio:Recercat. Dipósit de la Recerca de Catalunya
OAI Identifier:oai:recercat.cat:10230/59109
Acceso en línea:http://hdl.handle.net/10230/59109
http://dx.doi.org/10.1126/science.adk6160
Access Level:acceso abierto
Palabra clave:Microtúbuls
Tubulines
Descripción
Sumario: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.