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Nature
2020 Feb 01;5787795:467-471. doi: 10.1038/s41586-019-1896-6.
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Insights into the assembly and activation of the microtubule nucleator γ-TuRC.
Liu P, Zupa E, Neuner A, Böhler A, Loerke J, Flemming D, Ruppert T, Rudack T, Peter C, Spahn C, Gruss OJ, Pfeffer S, Schiebel E.
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Microtubules are dynamic polymers of α- and β-tubulin and have crucial roles in cell signalling, cell migration, intracellular transport and chromosome segregation1. They assemble de novo from αβ-tubulin dimers in an essential process termed microtubule nucleation. Complexes that contain the protein γ-tubulin serve as structural templates for the microtubule nucleation reaction2. In vertebrates, microtubules are nucleated by the 2.2-megadalton γ-tubulin ring complex (γ-TuRC), which comprises γ-tubulin, five related γ-tubulin complex proteins (GCP2-GCP6) and additional factors3. GCP6 is unique among the GCP proteins because it carries an extended insertion domain of unknown function. Our understanding of microtubule formation in cells and tissues is limited by a lack of high-resolution structural information on the γ-TuRC. Here we present the cryo-electron microscopy structure of γ-TuRC from Xenopus laevis at 4.8 Å global resolution, and identify a 14-spoked arrangement of GCP proteins and γ-tubulins in a partially flexible open left-handed spiral with a uniform sequence of GCP variants. By forming specific interactions with other GCP proteins, the GCP6-specific insertion domain acts as a scaffold for the assembly of the γ-TuRC. Unexpectedly, we identify actin as a bona fide structural component of the γ-TuRC with functional relevance in microtubule nucleation. The spiral geometry of γ-TuRC is suboptimal for microtubule nucleation and a controlled conformational rearrangement of the γ-TuRC is required for its activation. Collectively, our cryo-electron microscopy reconstructions provide detailed insights into the molecular organization, assembly and activation mechanism of vertebrate γ-TuRC, and will serve as a framework for the mechanistic understanding of fundamental biological processes associated with microtubule nucleation, such as meiotic and mitotic spindle formation and centriole biogenesis4.
Adams,
PHENIX: a comprehensive Python-based system for macromolecular structure solution.
2010, Pubmed
Adams,
PHENIX: a comprehensive Python-based system for macromolecular structure solution.
2010,
Pubmed Aldaz,
Insights into microtubule nucleation from the crystal structure of human gamma-tubulin.
2005,
Pubmed Anders,
Noncore components of the fission yeast gamma-tubulin complex.
2006,
Pubmed Bärenz,
The centriolar satellite protein SSX2IP promotes centrosome maturation.
2013,
Pubmed
,
Xenbase Borisy,
Microtubules: 50 years on from the discovery of tubulin.
2016,
Pubmed Buchan,
The PSIPRED Protein Analysis Workbench: 20 years on.
2019,
Pubmed Chinen,
The γ-tubulin-specific inhibitor gatastatin reveals temporal requirements of microtubule nucleation during the cell cycle.
2015,
Pubmed Choi,
CDK5RAP2 stimulates microtubule nucleation by the gamma-tubulin ring complex.
2010,
Pubmed Cox,
MaxQuant enables high peptide identification rates, individualized p.p.b.-range mass accuracies and proteome-wide protein quantification.
2008,
Pubmed Emsley,
Features and development of Coot.
2010,
Pubmed Farache,
Functional Analysis of γ-Tubulin Complex Proteins Indicates Specific Lateral Association via Their N-terminal Domains.
2016,
Pubmed Farina,
The centrosome is an actin-organizing centre.
2016,
Pubmed Guillet,
Crystal structure of γ-tubulin complex protein GCP4 provides insight into microtubule nucleation.
2011,
Pubmed Jones,
Protein secondary structure prediction based on position-specific scoring matrices.
1999,
Pubmed Kabsch,
Atomic structure of the actin:DNase I complex.
1990,
Pubmed Kelley,
The Phyre2 web portal for protein modeling, prediction and analysis.
2015,
Pubmed Kidmose,
Namdinator - automatic molecular dynamics flexible fitting of structural models into cryo-EM and crystallography experimental maps.
2019,
Pubmed Kollman,
Microtubule nucleating gamma-TuSC assembles structures with 13-fold microtubule-like symmetry.
2010,
Pubmed Kollman,
Microtubule nucleation by γ-tubulin complexes.
2011,
Pubmed Mastronarde,
Automated electron microscope tomography using robust prediction of specimen movements.
2005,
Pubmed Michalski,
The diagnosis of human immunodeficiency virus infection: progress in less than five years.
1989,
Pubmed Moritz,
Structure of the gamma-tubulin ring complex: a template for microtubule nucleation.
2000,
Pubmed Nakane,
Characterisation of molecular motions in cryo-EM single-particle data by multi-body refinement in RELION.
2018,
Pubmed Pei,
PROMALS3D web server for accurate multiple protein sequence and structure alignments.
2008,
Pubmed Petry,
Microtubule nucleation at the centrosome and beyond.
2015,
Pubmed Pettersen,
UCSF Chimera--a visualization system for exploratory research and analysis.
2004,
Pubmed Phillips,
Scalable molecular dynamics with NAMD.
2005,
Pubmed Ribeiro,
QwikMD - Integrative Molecular Dynamics Toolkit for Novices and Experts.
2016,
Pubmed Schmidt-Cernohorska,
Flagellar microtubule doublet assembly in vitro reveals a regulatory role of tubulin C-terminal tails.
2019,
Pubmed Schwanhäusser,
Global quantification of mammalian gene expression control.
2011,
Pubmed Scrofani,
Microtubule nucleation in mitosis by a RanGTP-dependent protein complex.
2015,
Pubmed
,
Xenbase Sievers,
Fast, scalable generation of high-quality protein multiple sequence alignments using Clustal Omega.
2011,
Pubmed Sievers,
Clustal Omega for making accurate alignments of many protein sequences.
2018,
Pubmed Tang,
EMAN2: an extensible image processing suite for electron microscopy.
2007,
Pubmed Trabuco,
Molecular dynamics flexible fitting: a practical guide to combine cryo-electron microscopy and X-ray crystallography.
2009,
Pubmed van Heel,
A new generation of the IMAGIC image processing system.
1996,
Pubmed Waterhouse,
Jalview Version 2--a multiple sequence alignment editor and analysis workbench.
2009,
Pubmed Zhang,
The role of Xgrip210 in gamma-tubulin ring complex assembly and centrosome recruitment.
2000,
Pubmed
,
Xenbase Zhang,
Gctf: Real-time CTF determination and correction.
2016,
Pubmed Zheng,
MotionCor2: anisotropic correction of beam-induced motion for improved cryo-electron microscopy.
2017,
Pubmed Zheng,
Nucleation of microtubule assembly by a gamma-tubulin-containing ring complex.
1995,
Pubmed
,
Xenbase Zivanov,
New tools for automated high-resolution cryo-EM structure determination in RELION-3.
2018,
Pubmed Zivanov,
A Bayesian approach to beam-induced motion correction in cryo-EM single-particle analysis.
2019,
Pubmed
