An ARF-independent c-MYC-activated tumor suppression pathway mediated by ribosomal protein-Mdm2 Interaction.
In vitro studies have shown that inhibition of ribosomal biogenesis can activate p53 through ribosomal protein (RP)-mediated suppression of Mdm2 E3 ligase activity. To study the physiological significance of the RP-Mdm2 interaction, we generated mice carrying a cancer-associated cysteine-to-phenylalanine substitution in the zinc finger of Mdm2 that disrupted its binding to RPL5 and RPL11. Mice harboring this mutation, retain normal p53 response to DNA damage, but lack of p53 response to perturbations in ribosome biogenesis. Loss of RP-Mdm2 interaction significantly accelerates Eμ-Myc-induced lymphomagenesis. Furthermore, ribosomal perturbation-induced p53 response does not require tumor suppressor p19ARF. Collectively, our findings establish RP-Mdm2 interaction as a genuine p53 stress-signaling pathway activated by aberrant ribosome biogenesis and essential for safeguarding against oncogenic c-MYC-induced tumorigenesis.
Pubmed ID: 20832751 RIS Download
Animals | DNA Damage | Genes, myc | Humans | Mice | Mice, Inbred C57BL | Mice, Transgenic | Protein Binding | Proto-Oncogene Proteins c-mdm2 | Proto-Oncogene Proteins c-myc | Ribosomal Proteins | Ribosomes | Signal Transduction | Tumor Suppressor Protein p14ARF | Tumor Suppressor Protein p53 | Zinc Fingers