Regulated inactivation of the spindle assembly checkpoint without functional mitotic spindles.
EMBO J
; 30(13): 2648-61, 2011 Jun 03.
Article
em En
| MEDLINE
| ID: mdl-21642954
ABSTRACT
The spindle assembly checkpoint (SAC) arrests mitosis until bipolar attachment of spindle microtubules to all chromosomes is accomplished. However, when spindle formation is prevented and the SAC cannot be satisfied, mammalian cells can eventually overcome the mitotic arrest while the checkpoint is still activated. We find that Aspergillus nidulans cells, which are unable to satisfy the SAC, inactivate the checkpoint after a defined period of mitotic arrest. Such SAC inactivation allows normal nuclear reassembly and mitotic exit without DNA segregation. We demonstrate that the mechanisms, which govern such SAC inactivation, require protein synthesis and can occur independently of inactivation of the major mitotic regulator Cdk1/Cyclin B or mitotic exit. Moreover, in the continued absence of spindle function cells transit multiple cell cycles in which the SAC is reactivated each mitosis before again being inactivated. Such cyclic activation and inactivation of the SAC suggests that it is subject to cell-cycle regulation that is independent of bipolar spindle function.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Aspergillus nidulans
/
Genes cdc
/
Mitose
/
Fuso Acromático
Idioma:
En
Revista:
EMBO J
Ano de publicação:
2011
Tipo de documento:
Article
País de afiliação:
Estados Unidos