System-level feedbacks make the anaphase switch irreversible.
Proc Natl Acad Sci U S A
; 108(24): 10016-21, 2011 Jun 14.
Article
em En
| MEDLINE
| ID: mdl-21617094
ABSTRACT
The mitotic checkpoint prevents a eukaryotic cell from commencing to separate its replicated genome into two daughter cells (anaphase) until all of its chromosomes are properly aligned on the metaphase plate, with the two copies of each chromosome attached to opposite poles of the mitotic spindle. The mitotic checkpoint is exquisitely sensitive in that a single unaligned chromosome, 1 of a total of ~50, is sufficient to delay progression into anaphase; however, when the last chromosome comes into alignment on the metaphase plate, the mitotic checkpoint is quickly satisfied, and the replicated chromosomes are rapidly partitioned to opposite poles of the dividing cell. The mitotic checkpoint is also curious in the sense that, before metaphase alignment, chromosomes that are not being pulled in opposite directions by the mitotic spindle activate the checkpoint, but during anaphase, these same tensionless chromosomes can no longer activate the checkpoint. These and other puzzles associated with the mitotic checkpoint are addressed by a proposed molecular mechanism, which involves two positive feedback loops that create a bistable response of the checkpoint to chromosomal tension.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Algoritmos
/
Retroalimentação Fisiológica
/
Anáfase
/
Modelos Genéticos
Limite:
Animals
/
Humans
Idioma:
En
Revista:
Proc Natl Acad Sci U S A
Ano de publicação:
2011
Tipo de documento:
Article
País de afiliação:
Reino Unido