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CM1-driven assembly and activation of yeast γ-tubulin small complex underlies microtubule nucleation.
- Source :
-
ELife [Elife] 2021 May 05; Vol. 10. Date of Electronic Publication: 2021 May 05. - Publication Year :
- 2021
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Abstract
- Microtubule (MT) nucleation is regulated by the γ-tubulin ring complex (γTuRC), conserved from yeast to humans. In Saccharomyces cerevisiae , γTuRC is composed of seven identical γ-tubulin small complex (γTuSC) sub-assemblies, which associate helically to template MT growth. γTuRC assembly provides a key point of regulation for the MT cytoskeleton. Here, we combine crosslinking mass spectrometry, X-ray crystallography, and cryo-EM structures of both monomeric and dimeric γTuSCs, and open and closed helical γTuRC assemblies in complex with Spc110p to elucidate the mechanisms of γTuRC assembly. γTuRC assembly is substantially aided by the evolutionarily conserved CM1 motif in Spc110p spanning a pair of adjacent γTuSCs. By providing the highest resolution and most complete views of any γTuSC assembly, our structures allow phosphorylation sites to be mapped, surprisingly suggesting that they are mostly inhibitory. A comparison of our structures with the CM1 binding site in the human γTuRC structure at the interface between GCP2 and GCP6 allows for the interpretation of significant structural changes arising from CM1 helix binding to metazoan γTuRC.<br />Competing Interests: AB, AL, AZ, SV, AM, MM, EM, AS, TD, DA No competing interests declared<br /> (© 2021, Brilot et al.)
- Subjects :
- Binding Sites
Calmodulin-Binding Proteins genetics
Calmodulin-Binding Proteins metabolism
Cryoelectron Microscopy methods
Crystallography, X-Ray methods
Cytoskeletal Proteins genetics
Cytoskeletal Proteins metabolism
Humans
Mass Spectrometry methods
Microtubule-Organizing Center
Saccharomyces cerevisiae Proteins genetics
Saccharomyces cerevisiae Proteins metabolism
Tubulin classification
Tubulin metabolism
Antigens, Nuclear genetics
Microtubules physiology
Saccharomyces cerevisiae genetics
Saccharomyces cerevisiae metabolism
Tubulin chemistry
Tubulin genetics
Subjects
Details
- Language :
- English
- ISSN :
- 2050-084X
- Volume :
- 10
- Database :
- MEDLINE
- Journal :
- ELife
- Publication Type :
- Academic Journal
- Accession number :
- 33949948
- Full Text :
- https://doi.org/10.7554/eLife.65168