Cyclin B/p34cdc2 Triggers Phosphorylation of DNA Ligase I During Xenopus laevis Oocyte Maturation

Saïd Aoufouchi, Claude Prigent, Chris Ford, Pierre Thiebaud, Michel Philippe, Nadine Theze

Résultats de recherche: Contribution à un journalArticleRevue par des pairs

7 Citations (Scopus)

Résumé

Phosphorylation of DNA ligase I has been analyzed during Xenopus laevis early development. The enzyme, which is involved in DNA replication and DNA repair events, is accumulated during oogenesis to reach a maximum in the stage VI oocyte, and remains at a constant level during maturation. When maturation of the oocyte is induced (in vivo or in vitro), this leads to a post‐translational modification of the protein. In stage VI oocytes, a DNA ligase I of apparent molecular mass 180 kDa is detected immuno‐logically whereas a 190‐kDa form is found in unfertilized eggs and persists until the tadpole stage. This modification is due to phosphorylation performed by a protein kinase that is turned on 3–4 h after induction of the maturation. Activation of the kinase requires protein synthesis, and appearance of phos‐phorylated DNA ligase coincides with activation of histone H1 kinase activity. Induction of DNA ligase I modification and maturation are induced in the absence of protein synthesis following injection of maturation promoting factor into oocytes. Immunoprecipitated oocyte DNA ligase I is phosphorylated and its molecular mass modified by purified cyclin B/p34cdc2in vitro. DNA ligase I phosphorylation is not induced in oocyte extract where only mitogen‐activated‐protein kinase is induced. Phosphorylation of DNA ligase I induced by cdc2 kinase occurs at the time new DNA replication and recombination activities appear in eggs.

langue originaleAnglais
Pages (de - à)491-497
Nombre de pages7
journalEuropean Journal of Biochemistry
Volume230
Numéro de publication2
Les DOIs
étatPublié - 1 janv. 1995
Modification externeOui

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