Analysis of JNK, Mdm2 and p14ARF contribution to the regulation of mutant p53 stability
| Autor: | Serge Y. Fuchs, Victor Adler, Toshinari Minamoto, Thomas Buschmann, Ze'ev Ronai, Nikhil Wagle, Masyoshi Mai |
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| Rok vydání: | 2000 |
| Předmět: |
Protein Conformation
Mutant Biology Transfection medicine.disease_cause Structural Biology In vivo Proto-Oncogene Proteins Tumor Suppressor Protein p14ARF Tumor Cells Cultured Null cell medicine Humans Molecular Biology Mutation Cell Membrane JNK Mitogen-Activated Protein Kinases Wild type Nuclear Proteins Proteins Proto-Oncogene Proteins c-mdm2 Zinc Fingers Fibroblasts Genes p53 Molecular biology Recombinant Proteins In vitro Kinetics biology.protein Mdm2 Mitogen-Activated Protein Kinases Tumor Suppressor Protein p53 Half-Life |
| Zdroj: | Journal of Molecular Biology. 295:1009-1021 |
| ISSN: | 0022-2836 |
| DOI: | 10.1006/jmbi.1999.3387 |
| Popis: | Identification of Mdm2 and JNK as proteins that target degradation of wt p53 prompted us to examine their effect on mutant p53, which exhibits a prolonged half-life. Of five mutant p53 forms studied for association with the targeting molecules, two no longer bound to Mdm2 and JNK. Three mutant forms, which exhibit high expression levels, showed lower affinity for association with Mdm2 and JNK in concordance with greater affinity to p14(ARF), which is among the stabilizing p53 molecules. Monitoring mutant p53 stability in vitro confirmed that, while certain forms of mutant p53 are no longer affected by either JNK or Mdm2, others are targeted for degradation by JNK/Mdm2, albeit at lower efficiency when compared with wt p53. Expression of wt p53 in tumor cells revealed a short half-life, suggesting that the targeting molecules are functional. Forced expression of mutant p53 in p53 null cells confirmed pattern of association with JNK/Mdm2 and prolonged half-life, as found in the tumor cells. Over-expression of Mdm2 in either tumor (which do express endogenous functional Mdm2) or in p53 null cells decreased the stability of mutant p53 suggesting that, despite its expression, Mdm2/JNK are insufficient (amount/affinity) for targeting mutant p53 degradation. Based on both in vitro and in vivo analyses, we conclude that the prolonged half-life of mutant p53 depends on the nature of the mutation, which either alters association with targeting molecules, ratio between p53 and targeting/stabilizing molecules or targeting efficiency. |
| Databáze: | OpenAIRE |
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