Polo-like kinase-1 phosphorylates MDM2 at Ser260 and stimulates MDM2-mediated p53 turnover.
The E3 ubiqutin ligase, murne double-minute clone 2 (MDM2), promotes the degradation of p53 under normal homeostatic conditions. Several serine residues within the acidic domain of MDM2 are phosphorylated to maintain its activity but become hypo-phosphorylated following DNA damage, leading to inactivation of MDM2 and induction of p53. However, the signalling pathways that mediate these phosphorylation events are not fully understood. Here we show that the oncogenic and cell cycle-regulatory protein kinase, polo-like kinase-1 (PLK1), phosphorylates MDM2 at one of these residues, Ser260, and stimulates MDM2-mediated turnover of p53. These data are consistent with the idea that deregulation of PLK1 during tumourigenesis may help suppress p53 function.
Dias
Sylvia S
SS
Biomedical Research Institute, Ninewells Hospital and Medical School, University of Dundee, Dundee DD1 9SY, United Kingdom.
Hogan
Carol
C
Ochocka
Anna-Maria
AM
Meek
David W
DW
D001665:Binding Sites / Q000235:genetics; D015153:Blotting, Western; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism*; D045744:Cell Line, Tumor; D006367:HeLa Cells; D006801:Humans; D047468:Immunoprecipitation; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism*; D051736:Proto-Oncogene Proteins c-mdm2 / Q000235:genetics / Q000378:metabolism*; D012694:Serine / Q000378:metabolism*; D014162:Transfection; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism*; D000097869:Polo-Like Kinase 1
D018797:Cell Cycle Proteins; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins; D051736:Proto-Oncogene Proteins c-mdm2; D012694:Serine; D016159:Tumor Suppressor Protein p53; D000097869:Polo-Like Kinase 1; C497206:MDM2 protein, human