Format

Send to

Choose Destination
Cell. 2017 Jun 1;169(6):1066-1077.e10. doi: 10.1016/j.cell.2017.05.028.

The Centrosome Is a Selective Condensate that Nucleates Microtubules by Concentrating Tubulin.

Author information

1
Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany. Electronic address: woodruff@mpi-cbg.de.
2
Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany.
3
Department of Chemistry and Molecular Biology, University of Gothenburg, Medicinaregatan 9 c, 40530 Gothenburg, Sweden.
4
Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany.
5
Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany. Electronic address: hyman@mpi-cbg.de.

Abstract

Centrosomes are non-membrane-bound compartments that nucleate microtubule arrays. They consist of nanometer-scale centrioles surrounded by a micron-scale, dynamic assembly of protein called the pericentriolar material (PCM). To study how PCM forms a spherical compartment that nucleates microtubules, we reconstituted PCM-dependent microtubule nucleation in vitro using recombinant C. elegans proteins. We found that macromolecular crowding drives assembly of the key PCM scaffold protein SPD-5 into spherical condensates that morphologically and dynamically resemble in vivo PCM. These SPD-5 condensates recruited the microtubule polymerase ZYG-9 (XMAP215 homolog) and the microtubule-stabilizing protein TPXL-1 (TPX2 homolog). Together, these three proteins concentrated tubulin ∼4-fold over background, which was sufficient to reconstitute nucleation of microtubule asters in vitro. Our results suggest that in vivo PCM is a selective phase that organizes microtubule arrays through localized concentration of tubulin by microtubule effector proteins.

KEYWORDS:

Centrosome; Polo Kinase; SPD-5; TPX2; XMAP215; microtubule-organizing center; pericentriolar material; phase separation; scaffold

PMID:
28575670
DOI:
10.1016/j.cell.2017.05.028
[Indexed for MEDLINE]
Free full text

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center