Abstract
The p53 tumor suppressor interacts with its negative regulator Mdm2 via the former's N-terminal region and core domain, yet the extreme p53 C-terminal region contains lysine residues ubiquitinated by Mdm2 and can bear post-translational modifications that inhibit Mdm2-p53 association. We show that the Mdm2-p53 interaction is decreased upon deletion, mutation or acetylation of the p53 C terminus. Mdm2 decreases the association of full-length but not C-terminally deleted p53 with a DNA target sequence in vitro and in cells. Further, using multiple approaches, we show that a peptide from the p53 C terminus directly binds the Mdm2 N terminus in vitro. We also show that p300-acetylated p53 inefficiently binds Mdm2 in vitro, and Nutlin-3 treatment induces C-terminal modification(s) of p53 in cells, explaining the low efficiency of Nutlin-3 in dissociating p53-MDM2 in vitro.
Publication types
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Research Support, N.I.H., Extramural
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Research Support, Non-U.S. Gov't
MeSH terms
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Animals
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Cross-Linking Reagents / pharmacology
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DNA / metabolism
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HCT116 Cells
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Humans
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Imidazoles / metabolism
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Mass Spectrometry
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Mice
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Models, Biological
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Piperazines / metabolism
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Protein Binding / drug effects
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Protein Interaction Mapping
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Protein Structure, Tertiary
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Proto-Oncogene Proteins c-mdm2 / chemistry*
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Proto-Oncogene Proteins c-mdm2 / metabolism*
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RNA, Small Interfering / metabolism
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Sequence Deletion / genetics
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Structure-Activity Relationship
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Tumor Suppressor Protein p14ARF / metabolism
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Tumor Suppressor Protein p53 / chemistry*
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Tumor Suppressor Protein p53 / metabolism*
Substances
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Cross-Linking Reagents
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Imidazoles
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Piperazines
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RNA, Small Interfering
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Tumor Suppressor Protein p14ARF
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Tumor Suppressor Protein p53
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nutlin 3
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DNA
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MDM2 protein, human
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Mdm2 protein, mouse
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Proto-Oncogene Proteins c-mdm2