MDM2-dependent ubiquitination of nuclear and cytoplasmic P53
| Autor: | Rory K. Geyer, Zhong Kang Yu, Carl G. Maki |
|---|---|
| Rok vydání: | 2000 |
| Předmět: |
Male
Cytoplasm Cancer Research Biology Transfection Proto-Oncogene Proteins c-mdm2 Salmon Proto-Oncogene Proteins Tumor Cells Cultured Genetics medicine Animals Humans Nuclear protein Nuclear export signal Ubiquitins Molecular Biology Cell Nucleus Cell growth Nuclear Proteins DNA Cell cycle Cell biology Cell nucleus medicine.anatomical_structure Fatty Acids Unsaturated Tumor Suppressor Protein p53 Nucleus |
| Zdroj: | Oncogene. 19:5892-5897 |
| ISSN: | 1476-5594 0950-9232 |
| DOI: | 10.1038/sj.onc.1203980 |
| Popis: | Wild-type p53 is stabilized and accumulates in the nucleus of DNA damaged cells. The effect of stabilizing p53 is to inhibit cell growth, either through a G1 cell cycle arrest or apoptotic cell death. MDM2 can inhibit p53 activity, in part, by promoting its rapid degradation through the ubiquitin proteolysis pathway. In the current study, MDM2-mediated degradation of p53 was partially inhibited in cells treated with leptomycin B (LMB), a specific inhibitor of nuclear export. In contrast, levels of ubiquitinated p53 increased in LMB-treated cells, indicating that nuclear export is not required for p53 ubiquitination. To investigate this further, p53 mutants were generated which localize to either the nucleus or cytoplasm, and their susceptibility to MDM2-mediated ubiquitination was assessed. p53 mutants that localized to either the nucleus or the cytoplasm were efficiently ubiquitinated, and their steady-state levels decreased, when coexpressed with MDM2. In addition, an MDM2-mutant that localized to the cytoplasm was able to ubiquitinate and degrade a p53 mutant which was similarly localized in the cytoplasm. Our results indicate that nuclear export is not required for p53 ubiquitination, and that p53 proteins that localize to either the nucleus or cytoplasm can be ubiquitinated and degraded by MDM2. |
| Databáze: | OpenAIRE |
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