hSIR2(SIRT1) functions as an NAD-dependent p53 deacetylase.
DNA damage-induced acetylation of p53 protein leads to its activation and either growth arrest or apoptosis. We show here that the protein product of the gene hSIR2(SIRT1), the human homolog of the S. cerevisiae Sir2 protein known to be involved in cell aging and in the response to DNA damage, binds and deacetylates the p53 protein with a specificity for its C-terminal Lys382 residue, modification of which has been implicated in the activation of p53 as a transcription factor. Expression of wild-type hSir2 in human cells reduces the transcriptional activity of p53. In contrast, expression of a catalytically inactive hSir2 protein potentiates p53-dependent apoptosis and radiosensitivity. We propose that hSir2 is involved in the regulation of p53 function via deacetylation.
Pubmed ID: 11672523 RIS Download
Animals | Apoptosis | Cell Line | Cyclin-Dependent Kinase Inhibitor p21 | Cyclins | DNA Damage | Dose-Response Relationship, Radiation | Fibroblasts | Flow Cytometry | Histone Deacetylases | Humans | Immunoblotting | Luciferases | Microscopy, Fluorescence | Models, Biological | Mutation | NAD | Peptides | Plasmids | Precipitin Tests | Protein Binding | Protein Structure, Tertiary | Silent Information Regulator Proteins, Saccharomyces cerevisiae | Sirtuin 1 | Sirtuin 2 | Sirtuins | Trans-Activators | Transcription, Genetic | Transfection | Tumor Suppressor Protein p53