Nuclear localization of CDC25B1 and serine 146 integrity are required for induction of mitosis.
CDC25B phosphatases are essential regulators that control cyclin-dependent kinases activities at the entry into mitosis. In this study, we demonstrate that serine 146 is required for two crucial features of CDC25B1. It is essential for CDC25B1 to function as a mitotic inducer and to prevent CDC25B1 export from the nucleus. We also show that serine 146 is phosphorylated in vitro by CDK1-cyclin B. However, phosphorylation of CDC25B does not stimulate its phosphatase activity, and mutation of serine 146 had no effect on its catalytic activity. Serine 146 phosphorylation is proposed to be a key event in the regulation of the CDC25B function in the initiation of mammalian mitosis.
Baldin
Véronique
V
LBCMCP-CNRS UMR5088, Université Paul Sabatier, 118 route de Narbonne, 31077 Toulouse, France.
Pelpel
Karine
K
Cazales
Martine
M
Cans
Christophe
C
Ducommun
Bernard
B
D018797:Cell Cycle Proteins / Q000737:chemistry / Q000378:metabolism* / Q000502:physiology; D002467:Cell Nucleus / Q000378:metabolism*; D006801:Humans; D008938:Mitosis / Q000502:physiology*; D010766:Phosphorylation; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D012694:Serine / Q000378:metabolism*; D014407:Tumor Cells, Cultured; D020687:cdc25 Phosphatases / Q000737:chemistry / Q000378:metabolism* / Q000502:physiology
D018797:Cell Cycle Proteins; D011994:Recombinant Proteins; D012694:Serine; C517008:CDC25B protein, human; D020687:cdc25 Phosphatases