Functional and physical interactions of the ARF tumor suppressor with p53 and Mdm2

  • Takehiko Kamijo
    Howard Hughes Medical Institute and Departments of Tumor Cell Biology and Biochemistry, St. Jude Children’s Research Hospital, 332 North Lauderdale, Memphis, TN 38105
  • Jason D. Weber
    Howard Hughes Medical Institute and Departments of Tumor Cell Biology and Biochemistry, St. Jude Children’s Research Hospital, 332 North Lauderdale, Memphis, TN 38105
  • Gerard Zambetti
    Howard Hughes Medical Institute and Departments of Tumor Cell Biology and Biochemistry, St. Jude Children’s Research Hospital, 332 North Lauderdale, Memphis, TN 38105
  • Frederique Zindy
    Howard Hughes Medical Institute and Departments of Tumor Cell Biology and Biochemistry, St. Jude Children’s Research Hospital, 332 North Lauderdale, Memphis, TN 38105
  • Martine F. Roussel
    Howard Hughes Medical Institute and Departments of Tumor Cell Biology and Biochemistry, St. Jude Children’s Research Hospital, 332 North Lauderdale, Memphis, TN 38105
  • Charles J. Sherr
    Howard Hughes Medical Institute and Departments of Tumor Cell Biology and Biochemistry, St. Jude Children’s Research Hospital, 332 North Lauderdale, Memphis, TN 38105

Description

<jats:p> The <jats:italic>INK4a-ARF</jats:italic> locus encodes two proteins, p16 <jats:sup>INK4a</jats:sup> and p19 <jats:sup>ARF</jats:sup> , that restrain cell growth by affecting the functions of the retinoblastoma protein and p53, respectively. Disruption of this locus by deletions or point mutations is a common event in human cancer, perhaps second only to the loss of p53. Using insect cells infected with baculovirus vectors and NIH 3T3 fibroblasts infected with ARF retrovirus, we determined that mouse p19 <jats:sup>ARF</jats:sup> can interact directly with p53, as well as with the p53 regulator mdm2. ARF can bind p53-DNA complexes, and it depends upon functional p53 to transcriptionally induce mdm2 and the cyclin-dependent kinase inhibitor p21 <jats:sup>Cip1</jats:sup> , and to arrest cell proliferation. Binding of p19 <jats:sup>ARF</jats:sup> to p53 requires the ARF N-terminal domain (amino acids 1–62) that is necessary and sufficient to induce cell cycle arrest. Overexpression of p19 <jats:sup>ARF</jats:sup> in wild type or <jats:italic>ARF</jats:italic> -null mouse embryo fibroblasts increases the half-life of p53 from 15 to ≈75 min, correlating with an increased p53-dependent transcriptional response and growth arrest. Surprisingly, when overexpressed at supra-physiologic levels after introduction into <jats:italic>ARF</jats:italic> -null NIH 3T3 cells or mouse embryo fibroblasts, the p53 protein is handicapped in inducing this checkpoint response. In this setting, reintroduction of p19 <jats:sup>ARF</jats:sup> restores p53’s ability to induce p21 <jats:sup>Cip1</jats:sup> and mdm2, implying that, in addition to stabilizing p53, ARF modulates p53-dependent function through an additional mechanism. </jats:p>

Journal

Citations (22)*help

See more

Details 詳細情報について

Report a problem

Back to top