Characterization of the TPX2 domains involved in microtubule nucleation and spindle assembly in Xenopus egg extracts.
Mol Biol Cell
; 15(12): 5318-28, 2004 Dec.
Article
em En
| MEDLINE
| ID: mdl-15385625
TPX2 has multiple functions during mitosis, including microtubule nucleation around the chromosomes and the targeting of Xklp2 and Aurora A to the spindle. We have performed a detailed domain functional analysis of TPX2 and found that a large N-terminal domain containing the Aurora A binding peptide interacts directly with and nucleates microtubules in pure tubulin solutions. However, it cannot substitute the endogenous TPX2 to support microtubule nucleation in response to Ran guanosine triphosphate (GTP) and spindle assembly in egg extracts. By contrast, a large C-terminal domain of TPX2 that does not bind directly to pure microtubules and does not bind Aurora A kinase rescues microtubule nucleation in response to RanGTP and spindle assembly in TPX2-depleted extract. These and previous results suggest that under physiological conditions, TPX2 is essential for microtubule nucleation around chromatin and functions in a network of other molecules, some of which also are regulated by RanGTP.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Oócitos
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Fosfoproteínas
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Xenopus laevis
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Proteínas Nucleares
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Extratos Celulares
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Proteínas de Ciclo Celular
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Proteínas de Xenopus
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Proteínas Associadas aos Microtúbulos
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Microtúbulos
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Fuso Acromático
Limite:
Animals
Idioma:
En
Ano de publicação:
2004
Tipo de documento:
Article