Related Experiment Video

Updated: May 21, 2026

Selective Capture of 5-hydroxymethylcytosine from Genomic DNA
06:26

Selective Capture of 5-hydroxymethylcytosine from Genomic DNA

Published on: October 5, 2012

Deamination of 5-methylcytosine residues in Mammalian cells

E V Gromenko1, P V Spirin, E A Kubareva

  • 1Department of Chemistry, Lomonosov Moscow State University;

Acta Naturae
|June 1, 2012
PubMed

Insights

Mammalian DNA demethylation involves 5-methylcytosine deamination. This process, observed in cell extracts, is proposed as the initial step in DNA demethylation during development and disease.

Area of Science:

  • Epigenetics
  • Molecular Biology
  • Mammalian Genetics

Background:

  • DNA demethylation is crucial in mammalian development, aging, and cancer.
  • The precise mechanisms of DNA demethylation in mammals remain under investigation.

Purpose of the Study:

  • To investigate the initial molecular events in mammalian DNA demethylation.
  • To test the hypothesis that 5-methylcytosine deamination is the first step.

Main Methods:

  • Utilized primer extension assays.
  • Employed Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry (MALDI MS).
  • Incorporated DNA cleavage by thymine DNA glycosylase on methylated DNA duplexes treated with nuclear extracts (CHO, HeLa, Skov3 cells).

Main Results:

  • Demonstrated deamination of 5-methylcytosine residues in methylated DNA duplexes.
  • Observed this deamination when treated with nuclear extracts from various mammalian cell lines.

Conclusions:

  • Postulated that the deamination of 5-methylcytosine is the primary initiating event in mammalian DNA demethylation.
  • This finding provides a key insight into the fundamental epigenetic regulation in mammals.

More Related Videos

Detection of Modified Forms of Cytosine Using Sensitive Immunohistochemistry07:13

Detection of Modified Forms of Cytosine Using Sensitive Immunohistochemistry

Published on: August 16, 2016

Immunohistochemical Detection of 5-Methylcytosine and 5-Hydroxymethylcytosine in Developing and Postmitotic Mouse Retina07:50

Immunohistochemical Detection of 5-Methylcytosine and 5-Hydroxymethylcytosine in Developing and Postmitotic Mouse Retina

Published on: August 29, 2018

Related Concept Videos

mRNA Stability and Gene Expression02:51

mRNA Stability and Gene Expression

The structure and stability of mRNA molecules regulates gene expression, as mRNAs are a key step in the pathway from gene to protein. In eukaryotes, the half-life of mRNA varies from a few minutes up to several days. mRNA stability is essential in growth and development. The absence of the proteins regulating its stability, such as tristetraprolin in mice, can cause systemic issues, including bone marrow overgrowth, inflammation, and autoimmunity.
Cis-acting Elements involved in mRNA stability
RNA Editing02:23

RNA Editing

RNA editing is a post-transcriptional modification where a precursor mRNA (pre-mRNA) nucleotide sequence is changed by base insertion, deletion, or modification. The extent of RNA editing varies from a few hundred bases, in mitochondrial DNA of trypanosomes, to a just single base, in nuclear genes of mammals. Even a single base change in the pre-mRNA can convert a codon for one amino acid into the codon for another amino acid or a stop codon. This type of re-coding can significantly affect the...
Phase II Reactions: Methylation Reactions01:17

Phase II Reactions: Methylation Reactions

Methylation is a phase II biotransformation process involving the attachment of a methyl group to a substrate. Enzymes known as methyltransferases orchestrate this reaction.
The mechanism of methylation unfolds in two stages. The first stage sees a methyltransferase enzyme facilitating the transfer of a methyl group from S-adenosylmethionine (SAM) to the substrate, forming S-adenosylhomocysteine (SAH). The second stage involves further metabolism of SAH into homocysteine, which can be recycled...
Epigenetic Regulation01:37

Epigenetic Regulation

Epigenetic changes alter the physical structure of the DNA without changing the genetic sequence and often regulate whether genes are turned on or off. This regulation ensures that each cell produces only proteins necessary for its function. For example, proteins that promote bone growth are not produced in muscle cells. Epigenetic mechanisms play an essential role in healthy development. Conversely, precisely regulated epigenetic mechanisms are disrupted in diseases like cancer.
X-chromosome...
Epigenetic Regulation01:46

Epigenetic Regulation

Epigenetic mechanisms play an essential role in healthy development. Conversely, precisely regulated epigenetic mechanisms are disrupted in diseases like cancer.
In-vitro Mutagenesis01:16

In-vitro Mutagenesis

To learn more about the function of a gene, researchers can observe what happens when the gene is inactivated or “knocked out,” by creating genetically engineered knockout animals. Knockout mice have been particularly useful as models for human diseases such as cancer, Parkinson’s disease, and diabetes.