Bisulfite treatment can be used to ascertain the methylation states of individual cytosines in DNA. Ideally, bisulfite treatment deaminates unmethylated cytosines to uracils, and leaves 5-methylcytosines unchanged. Two types of bisulfite-conversion error occur: inappropriate conversion of 5-methylcytosine to thymine, and failure to convert unmethylated cytosine to uracil. Conventional bisulfite...

An efficient route for the synthesis of the phosphoramidite derivative of 5-methylcytosine bearing a tert-butylsulfanyl group protected thiol is described. This building block is used for the preparation of oligonucleotides carrying a thiol group at the nucleobase at the internal position of a DNA sequence. The resulting thiolated oligonucleotides are useful intermediates to generate oligonucle...

DNA dioxygenases Ten-Eleven Translocation (TET) proteins can catalyze the conversion of 5-methylcytosine (5mC) of DNA to 5-hydroxymethylcytosine (5hmC), and thereby alter the epigenetic state of DNA. The TET family includes TET1, TET2 and TET3 members in mammals. Recently, accumulative research uncovered that TET1-3 occur abundantly in the central nervous system (CNS), and their biological func...

The molecular mechanisms leading to brain tumors still remain unclear. Nevertheless, there is increasing evidence that epigenetic effects play crucial roles in tumor development and progression. Thereby, 5-hydroxymethylcytosine (5hmC) represents a further base modification of cytosine besides 5-methylcytosine (5mC). In addition to the role of 5hmC as an intermediate in demethylation, 5hmC is of...

Dioxygenases of the Ten-Eleven Translocation (TET) family are 5-methylcytosine oxidases that convert 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC) and further oxidation products in DNA. We show that Tet1 and Tet2 have distinct roles in regulating 5hmC in mouse embryonic stem cells (mESC). Tet1 depletion diminishes 5hmC levels at transcription start sites (TSS), whereas Tet2 depletion...

The two important epigenetic markers in the human genome, 5-methylcytosine (mC) and 5-hydroxymethylcytosine (hmC), are involved in gene regulation processes. As a major epigenetic target, cytosines in a C-rich DNA sequence were substituted with mC and hmC to investigate the thermal stability and pH sensitivity of the corresponding i-motifs. Circular Dichroism (CD) studies indicate the formation...

DNA cytosine methylation is a widespread epigenetic mark. Biological effects of DNA methylation are mediated by the proteins that preferentially bind to 5-methylcytosine (5mC) in different sequence contexts. Until now two different structural mechanisms have been established for 5mC recognition in eukaryotes; however, it is still unknown how discrimination of the 5mC modification is achieved in...

5-hydroxymethylcytosine (5hmC) is a recently re-discovered transient intermediate in the active demethylation pathway that also appears to play an independent role in modulating gene function. Epigenetic marks, particularly 5-methylcytosine, have been widely studied in relation to stress-related disorders given the long-lasting effect that stress has on these marks. 5hmC is a good candidate for...