Evidence that DNA replication is not regulated by ubiquitin-dependent proteolysis in Xenopus egg extract.
Exp Cell Res
; 288(2): 225-34, 2003 Aug 15.
Article
em En
| MEDLINE
| ID: mdl-12915114
ABSTRACT
The Xenopus early embryonic cell cycle consists of rapid oscillations between mitosis and DNA synthesis. We used ubiquitin (Ub)-dependent proteolysis inhibitors to determine whether Ub-mediated proteolysis regulates the initiation of DNA replication in Xenopus egg extract. Methylated Ub, a chemically modified Ub that cannot form chains, and S5a, a Ub chain-binding subunit of the 26S proteasome, were added to extract at concentrations known to inhibit cyclin B proteolysis and their effects on cell cycle progression and DNA replication were examined. DNA replication initiated concomitant with controls and proceeded in a semiconservative fashion in the presence of both methylated Ub and S5a. However, mitotic progression was halted, showing that the inhibitors were functional. We conclude that initiation of DNA replication is not regulated by Ub-dependent proteolysis in the early Xenopus cell cycle.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Oócitos
/
Ubiquitina
/
Replicação do DNA
Limite:
Animals
/
Humans
Idioma:
En
Revista:
Exp Cell Res
Ano de publicação:
2003
Tipo de documento:
Article
País de afiliação:
Estados Unidos