title: Phosphorylation of p53 is regulated by TPX2-Aurora A in xenopus oocytes.
abstract: p53 is an important tumor suppressor regulating the cell cycle at multiple stages in higher vertebrates. The p53 gene is frequently deleted or mutated in human cancers, resulting in loss of p53 activity. This leads to centrosome amplification, aneuploidy, and tumorigenesis, three phenotypes also observed after overexpression of the oncogenic kinase Aurora A. Accordingly, recent studies have focused on the relationship between these two proteins. p53 and Aurora A have been reported to interact in mammalian cells, but the function of this interaction remains unclear. We recently reported that Xenopus p53 can inhibit Aurora A activity in vitro but only in the absence of TPX2. Here we investigate the interplay between Xenopus Aurora A, TPX2, and p53 and show that newly synthesized TPX2 is required for nearly all Aurora A activation and for full p53 synthesis and phosphorylation in vivo during oocyte maturation. In vitro, phosphorylation mediated by Aurora A targets serines 129 and 190 within the DNA binding domain of p53. Glutathione S-transferase pull-down studies indicate that the interaction occurs via the p53 transactivation domain and the Aurora A catalytic domain around the T-loop. Our studies suggest that targeting of TPX2 might be an effective strategy for specifically inhibiting the phosphorylation of Aurora A substrates, including p53.
authors.affiliation: Howard Hughes Medical Institute and Department of Pharmacology, University of Colorado School of Medicine, Aurora, Colorado 80045, USA.
authors.forename: Gaetan
authors.initials: G
authors.lastname: Pascreau
authors.forename: Frank
authors.initials: F
authors.lastname: Eckerdt
authors.forename: Andrea L
authors.initials: AL
authors.lastname: Lewellyn
authors.forename: Claude
authors.initials: C
authors.lastname: Prigent
authors.forename: James L
authors.initials: JL
authors.lastname: Maller
mesh_terms: D000818:Animals; D064127:Aurora Kinases; D018797:Cell Cycle Proteins / Q000378:metabolism*; D005260:Female; D005982:Glutathione Transferase / Q000235:genetics / Q000378:metabolism; D047468:Immunoprecipitation; D008869:Microtubule-Associated Proteins / Q000378:metabolism*; D009687:Nuclear Proteins / Q000378:metabolism*; D009865:Oocytes / Q000166:cytology / Q000378:metabolism*; D010750:Phosphoproteins / Q000378:metabolism*; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D011994:Recombinant Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D015533:Transcriptional Activation; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism*; D029867:Xenopus Proteins / Q000378:metabolism*; D014982:Xenopus laevis / Q000254:growth & development / Q000378:metabolism*
chemical_list: D018797:Cell Cycle Proteins; D008869:Microtubule-Associated Proteins; D009687:Nuclear Proteins; D010750:Phosphoproteins; D011994:Recombinant Proteins; C486551:TPX2 protein, Xenopus; D016159:Tumor Suppressor Protein p53; D029867:Xenopus Proteins; D005982:Glutathione Transferase; D064127:Aurora Kinases; D017346:Protein Serine-Threonine Kinases