Chromosomal enrichment and activation of the aurora B pathway are coupled to spatially regulate spindle assembly.
Dev Cell
; 12(1): 31-43, 2007 Jan.
Article
em En
| MEDLINE
| ID: mdl-17199039
ABSTRACT
Chromatin-induced spindle assembly depends on regulation of microtubule-depolymerizing proteins by the chromosomal passenger complex (CPC), consisting of Incenp, Survivin, Dasra (Borealin), and the kinase Aurora B, but the mechanism and significance of the spatial regulation of Aurora B activity remain unclear. Here, we show that the Aurora B pathway is suppressed in the cytoplasm of Xenopus egg extract by phosphatases, but that it becomes activated by chromatin via a Ran-independent mechanism. While spindle microtubule assembly normally requires Dasra-dependent chromatin binding of the CPC, this function of Dasra can be bypassed by clustering Aurora B-Incenp by using anti-Incenp antibodies, which stimulate autoactivation among bound complexes. However, such chromatin-independent Aurora B pathway activation promotes centrosomal microtubule assembly and produces aberrant achromosomal spindle-like structures. We propose that chromosomal enrichment of the CPC results in local kinase autoactivation, a mechanism that contributes to the spatial regulation of spindle assembly and possibly to other mitotic processes.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Xenopus
/
Cromossomos
/
Proteínas Serina-Treonina Quinases
/
Fuso Acromático
Limite:
Animals
Idioma:
En
Ano de publicação:
2007
Tipo de documento:
Article