Remodelling the Rad9 checkpoint complex: preparing Rad53 for action.
Cell Cycle
; 3(2): 119-22, 2004 Feb.
Article
em En
| MEDLINE
| ID: mdl-14712069
ABSTRACT
DNA damage checkpoints are signal transduction pathways that are activated after genotoxic insults to protect genomic integrity. The Rad9 protein functions in the DNA damage checkpoint pathway in Saccharomyces cerevisiae and is essential for the Mec1-dependent activation of the effector kinase Rad53. We recently described the purification of two soluble distinct Rad9 complexes. The large 850 kDa complex consists of hypophosphorylated Rad9 and the chaperone proteins Ssa1/2. This complex is found both in undamaged cells as well as in cells treated with DNA damaging agents. The smaller 560 kDa complex contains hyperphosphorylated Rad9, Ssa1/2 and, in addition, Rad53. This complex forms only in cells with compromised DNA integrity. Once bound to the smaller complex, Rad53 can be activated by in trans autophosphorylation. Here, we propose a model in which the large Rad9 complex is remodelled after a genomic insult by chaperone activity to a smaller Rad53 activating complex.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Dano ao DNA
/
Proteínas Fúngicas
/
Proteínas Serina-Treonina Quinases
/
Proteínas de Choque Térmico HSP70
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Proteínas de Ciclo Celular
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Proteínas de Saccharomyces cerevisiae
Idioma:
En
Revista:
Cell Cycle
Ano de publicação:
2004
Tipo de documento:
Article
País de afiliação:
Irlanda