Critical Role for a Central Part of Mdm2 in the Ubiquitylation of p53

ABSTRACT The stability of the p53 protein is regulated by Mdm2. By acting as an E3 ubiquitin ligase, Mdm2 directs the ubiquitylation of p53 and its subsequent degradation by the 26S proteasome. In contrast, the Mdmx protein, although structurally similar to Mdm2, cannot ubiquitylate or degrade p53 in vivo. To ascertain which domains determine this functional difference between Mdm2 and Mdmx and consequently are essential for p53 ubiquitylation and degradation, we generated Mdm2-Mdmx chimeric constructs. Here we show that, in addition to a fully functional Mdm2 RING finger, an internal domain of Mdm2 (residues 202 to 302) is essential for p53 ubiquitylation. Strikingly, the function of this domain can be fulfilled in trans, indicating that the RING domain and this internal region perform distinct activities in the ubiquitylation of p53.

[1]  H. Kawai,et al.  Critical Contribution of the MDM2 Acidic Domain to p53 Ubiquitination , 2003, Molecular and Cellular Biology.

[2]  Muyang Li,et al.  Acetylation of p53 Inhibits Its Ubiquitination by Mdm2* , 2002, The Journal of Biological Chemistry.

[3]  Yoshiharu Kawaguchi,et al.  MDM2–HDAC1‐mediated deacetylation of p53 is required for its degradation , 2002, The EMBO journal.

[4]  Jiandong Chen,et al.  DNA Damage Induces MDMX Nuclear Translocation by p53-Dependent and -Independent Mechanisms , 2002, Molecular and Cellular Biology.

[5]  D. Lane,et al.  Hypophosphorylation of Mdm2 Augments p53 Stability , 2002, Molecular and Cellular Biology.

[6]  T. Hupp,et al.  The Conformationally Flexible S9–S10 Linker Region in the Core Domain of p53 Contains a Novel MDM2 Binding Site Whose Mutation Increases Ubiquitination of p53 in Vivo * , 2002, The Journal of Biological Chemistry.

[7]  K. Helin,et al.  Mdm4 (Mdmx) Regulates p53-Induced Growth Arrest and Neuronal Cell Death during Early Embryonic Mouse Development , 2002, Molecular and Cellular Biology.

[8]  Xin Lu,et al.  Live or let die: the cell's response to p53 , 2002, Nature Reviews Cancer.

[9]  R. Ramirez-Solis,et al.  mdmx is a negative regulator of p53 activity in vivo. , 2002, Cancer research.

[10]  A. Jochemsen,et al.  Mutual Dependence of MDM2 and MDMX in Their Functional Inactivation of p53* , 2002, The Journal of Biological Chemistry.

[11]  P. Pelicci,et al.  Hdmx Recruitment into the Nucleus by Hdm2 Is Essential for Its Ability to Regulate p53 Stability and Transactivation* , 2002, The Journal of Biological Chemistry.

[12]  M. Roussel,et al.  The RING domain of Mdm2 can inhibit cell proliferation. , 2002, Cancer research.

[13]  Moshe Oren,et al.  The p53 and Mdm2 families in cancer. , 2002, Current opinion in genetics & development.

[14]  D. Wiederschain,et al.  Identification of p53 Sequence Elements That Are Required for MDM2-Mediated Nuclear Export , 2001, Molecular and Cellular Biology.

[15]  N. Little,et al.  Mdmx stabilizes p53 and Mdm2 via two distinct mechanisms , 2001, EMBO reports.

[16]  D. Lane,et al.  Cocompartmentalization of p53 and Mdm2 is a major determinant for Mdm2-mediated degradation of p53. , 2001, Experimental cell research.

[17]  Valerie Reinke,et al.  Rescue of embryonic lethality in Mdm4-null mice by loss of Trp53 suggests a nonoverlapping pathway with MDM2 to regulate p53 , 2001, Nature Genetics.

[18]  D. Lane,et al.  Different effects of p14ARF on the levels of ubiquitinated p53 and Mdm2 in vivo , 2001, Oncogene.

[19]  M. Wani,et al.  Mdm2 Mutant Defective in Binding p300 Promotes Ubiquitination but Not Degradation of p53* , 2001, The Journal of Biological Chemistry.

[20]  N. Little,et al.  Hdmx and Mdm2 can repress transcription activation by p53 but not by p63 , 2001, Oncogene.

[21]  B. Wasylyk,et al.  The contribution of the acidic domain of MDM2 to p53 and MDM2 stability , 2001, Oncogene.

[22]  C. Maki,et al.  MDM2-dependent ubiquitination of nuclear and cytoplasmic P53 , 2000, Oncogene.

[23]  N. Little,et al.  Hdmx stabilizes Mdm2 and p53. , 2000, The Journal of biological chemistry.

[24]  Shengyun Fang,et al.  Mdm2 Is a RING Finger-dependent Ubiquitin Protein Ligase for Itself and p53* , 2000, The Journal of Biological Chemistry.

[25]  R. Honda,et al.  Activity of MDM2, a ubiquitin ligase, toward p53 or itself is dependent on the RING finger domain of the ligase , 2000, Oncogene.

[26]  M. Jackson,et al.  MdmX Protects p53 from Mdm2-Mediated Degradation , 2000, Molecular and Cellular Biology.

[27]  Xin Lu,et al.  RB regulates the stability and the apoptotic function of p53 via MDM2. , 1999, Molecular cell.

[28]  Yolande F M Ramos,et al.  Comparative study of the p53-mdm2 and p53-MDMX interfaces , 1999, Oncogene.

[29]  C. Prives.  Signaling to p53 Breaking the MDM2–p53 Circuit , 1998, Cell.

[30]  Hirofumi Tanaka,et al.  Oncoprotein MDM2 is a ubiquitin ligase E3 for tumor suppressor p53 , 1997, FEBS letters.

[31]  M. Oren,et al.  Mdm2 promotes the rapid degradation of p53 , 1997, Nature.

[32]  Stephen N. Jones,et al.  Regulation of p53 stability by Mdm2 , 1997, Nature.

[33]  A. Jochemsen,et al.  MDMX: a novel p53‐binding protein with some functional properties of MDM2. , 1996, The EMBO journal.

[34]  Lawrence A. Donehower,et al.  Rescue of embryonic lethality in Mdm2-deficient mice by absence of p53 , 1995, Nature.

[35]  Guillermina Lozano,et al.  Rescue of early embryonic lethality in mdm2-deficient mice by deletion of p53 , 1995, Nature.

[36]  A. Levine,et al.  The mdm-2 oncogene product forms a complex with the p53 protein and inhibits p53-mediated transactivation , 1992, Cell.

[37]  A. Levine,et al.  Regulation of Transcription Functions of the p53 Tumor Suppressor by the mdm-2 Oncogene , 1995, Molecular medicine.