The Centrosome Is a Selective Condensate that Nucleates Microtubules by Concentrating Tubulin.
Cell
; 169(6): 1066-1077.e10, 2017 Jun 01.
Article
en En
| MEDLINE
| ID: mdl-28575670
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 â¼4-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.
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Texto completo:
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MEDLINE
Asunto principal:
Tubulina (Proteína)
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Caenorhabditis elegans
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Centrosoma
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Proteínas de Ciclo Celular
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Proteínas de Caenorhabditis elegans
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Microtúbulos
Límite:
Animals
Idioma:
En
Año:
2017
Tipo del documento:
Article