Figure - PMC

Skip to main content

An official website of the United States government

Here's how you know

Here's how you know

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

View full-text article in PMC

. 2019 Nov 14;11(11):2763. doi: 10.3390/nu11112763

Search in PMC
Search in PubMed
View in NLM Catalog
Add to search

© 2019 by the authors.

Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).

PMC Copyright notice

DNA methylation and demethylation in humans. DNA methylation (upper panel) producing 5-methylcytosine (5mC) is catalyzed by DNA methyltransferases (DNMT). DNMT1 methylates hemimethylated DNA (maintenance methylation) and can be assisted by UHRF1 (ubiquitin like with PHD (plant homeodomain) and ring finger domains 1). DNMT3A and DNMT3B are involved in de novo DNA methylation; 5mC can be reverted to C passively or actively (lower panel) and may undergo spontaneous or activation-induced deaminase (AID)-mediated deamination converting it into thymine (T), which can be replaced with C via DNA repair with TDG (thymine DNA glycosylase) or SMUG1 (single-strand-selective monofunctional uracil-DNA glycosylase 1) glycosylases. Active demethylation is led by the ten eleven translocation (TET) proteins TET1-3 with the following intermediates: 5-hydroxymethylcytosine (5hmC), 5-formylcytosine (5fC), and 5-carboxylcytosine (5caC). 5hmC can be converted to 5 hydroxymethyluracil (5hmU) or T.