Abstract | BACKGROUND: RESULTS: Ascorbate significantly and specifically enhances Tet-mediated generation of 5-hmC. CONCLUSION: Our findings suggest that ascorbate enhances 5-hmC generation, most likely by acting as a co-factor for Tet methylcytosine dioxygenase to generate 5-hmC. SIGNIFICANCE: The availability of ascorbate could have significant consequences for health and diseases by modulating the epigenetic control of genome activity. Ascorbate ( vitamin C) is best known for its role in scurvy, in which the hydroxylation of collagen catalyzed by dioxygenases is incomplete due to ascorbate deficiency. Here, we report a novel function of ascorbate in the hydroxylation of 5-methylcytosine (5-mC) to 5-hydroxymethylcytosine (5-hmC) in DNA catalyzed by Tet (ten-eleven translocation) methylcytosine dioxygenase. The content of 5-hmC is extremely low in mouse embryonic fibroblasts cultured in ascorbate-free medium. Additions of ascorbate dose- and time-dependently enhance the generation of 5-hmC, without any effects on the expression of Tet genes. Treatment with another reducer glutathione (GSH) does not change the level of 5-hmC. Further, blocking ascorbate entry into cells by phloretin and knocking down Tet (Tet1, Tet2, and Tet3) expression by short interference RNAs ( siRNA) significantly inhibit the effect of ascorbate on 5-hmC. These results suggest that ascorbate enhances 5-hmC generation, most likely by acting as a co-factor for Tet methylcytosine dioxygenase to hydroxylate 5-mC. Thus, we have uncovered a novel role for ascorbate in modulating the epigenetic control of genome activity.
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Authors | Emily A Minor, Brenda L Court, Juan I Young, Gaofeng Wang |
Journal | The Journal of biological chemistry
(J Biol Chem)
Vol. 288
Issue 19
Pg. 13669-74
(May 10 2013)
ISSN: 1083-351X [Electronic] United States |
PMID | 23548903
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Chemical References |
- DNA-Binding Proteins
- Proto-Oncogene Proteins
- RNA, Small Interfering
- TET1 protein, mouse
- 5-hydroxymethylcytosine
- 5-Methylcytosine
- Cytosine
- Dioxygenases
- Tet2 protein, mouse
- Tet3 protein, mouse
- Ascorbic Acid
- Phloretin
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Topics |
- 5-Methylcytosine
(analogs & derivatives)
- Animals
- Ascorbic Acid
(pharmacology, physiology)
- Cells, Cultured
- Cytosine
(analogs & derivatives, biosynthesis)
- DNA Methylation
- DNA-Binding Proteins
(genetics, metabolism)
- Dioxygenases
- Epigenesis, Genetic
- Gene Knockdown Techniques
- Hydroxylation
- Mice
- Mice, Inbred C57BL
- Phloretin
(pharmacology)
- Proto-Oncogene Proteins
(genetics, metabolism)
- RNA, Small Interfering
(genetics)
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