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Human retinoblastoma protein (Rb) is phosphorylated by cdc2 kinase and MAP kinase in Xenopus maturing oocytes
Author(s) -
Taieb Frédéric,
Karaiskou Anthi,
Rime Hélène,
Jessus Catherine
Publication year - 1998
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(98)00291-9
Subject(s) - cyclin dependent kinase 1 , xenopus , microbiology and biotechnology , maturation promoting factor , cyclin b1 , mitogen activated protein kinase kinase , cyclin dependent kinase 2 , chemistry , cyclin b , prophase , kinase , oocyte , protein kinase a , cyclin dependent kinase 4 , cyclin dependent kinase complex , biology , cell cycle , cyclin , meiosis , cell , biochemistry , embryo , gene
Xenopus oocyte meiotic maturation combines features of G0/G1 and G2/M transitions of the cell cycle. To study the in ovo Rb kinase activity, we have microinjected human Rb into oocytes. Microinjected human Rb localizes into the nucleus, is hypophosphorylated in prophase oocytes, becomes hyperphosphorylated during meiotic maturation and is dephosphorylated as the cell reenters interphase. Inactivation or overexpression of the cyclin D‐cdk4/6 complex in an oocyte extract does not affect the Rb kinase activity. This kinase activity could be attributed to both cdc2‐cyclin B and MAP kinase, opening new perspectives of investigation in somatic cells.