Abstract
Nutrient availability regulates life-span in a wide range of organisms. We demonstrate that in mammalian cells, acute nutrient withdrawal simultaneously augments expression of the SIRT1 deacetylase and activates the Forkhead transcription factor Foxo3a. Knockdown of Foxo3a expression inhibited the starvation-induced increase in SIRT1 expression. Stimulation of SIRT1 transcription by Foxo3a was mediated through two p53 binding sites present in the SIRT1 promoter, and a nutrient-sensitive physical interaction was observed between Foxo3a and p53. SIRT1 expression was not induced in starved p53-deficient mice. Thus, in mammalian cells, p53, Foxo3a, and SIRT1, three proteins separately implicated in aging, constitute a nutrient-sensing pathway.
MeSH terms
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Adipose Tissue / metabolism
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Animals
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Binding Sites
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Culture Media
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Culture Media, Serum-Free
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DNA-Binding Proteins / metabolism*
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Forkhead Box Protein O1
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Forkhead Transcription Factors
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Gene Deletion
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Genes, p53
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Glucose
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HeLa Cells
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Humans
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Mice
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Mice, Inbred C57BL
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Mutation
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PC12 Cells
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Promoter Regions, Genetic
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RNA, Small Interfering / pharmacology
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Rats
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Recombinant Fusion Proteins / metabolism
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Recombinant Proteins / metabolism
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Serum
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Sirtuin 1
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Sirtuins / genetics
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Sirtuins / metabolism*
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Starvation*
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Transcription Factors / metabolism*
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Transcription, Genetic
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Tumor Suppressor Protein p53 / metabolism
Substances
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Culture Media
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Culture Media, Serum-Free
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DNA-Binding Proteins
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FOXO1 protein, human
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Forkhead Box Protein O1
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Forkhead Transcription Factors
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RNA, Small Interfering
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Recombinant Fusion Proteins
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Recombinant Proteins
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Transcription Factors
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Tumor Suppressor Protein p53
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Sirt1 protein, mouse
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Sirt1 protein, rat
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Sirtuin 1
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Sirtuins
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Glucose