New Insights into 5hmC DNA Modification: Generation, Distribution and Function.

Dong-Qiao Shi,Wei-Cai Yang,Iftikhar Ali,Jun Tang

doi:10.3389/fgene.2017.00100

Abstract

Dynamic DNA modifications, such as methylation/demethylation on cytosine, are major epigenetic mechanisms to modulate gene expression in both eukaryotes and prokaryotes. In addition to the common methylation on the 5th position of the pyrimidine ring of cytosine (5mC), other types of modifications at the same position, such as 5-hydroxymethyl (5hmC), 5-formyl (5fC), and 5-carboxyl (5caC), are also important. Recently, 5hmC, a product of 5mC demethylation by the Ten-Eleven Translocation family proteins, was shown to regulate many cellular and developmental processes, including the pluripotency of embryonic stem cells, neuron development, and tumorigenesis in mammals. Here, we review recent advances on the generation, distribution, and function of 5hmC modification in mammals and discuss its potential roles in plants.

Highlights

From two decades of studies, it is clear that the primary sequence information of DNA can be enhanced by epigenetic modifications
Zeng et al (2016) reported that Lin28A, a paralog of Lin28 that is preferentially expressed in mouse embryos and embryo stem cells (ESCs) before differentiation, can recruit TET1 to DNA and facilitate the conversion of 5mC to 5hmC and demethylation of gene bodies (Tan and Yeo, 2016)
More 5hmC is found in gene bodies of active genes, and TET1 is often observed at TSS of genes with high CpG promoters that are marked by the bivalent histone signature of H3K27me3 and H3K4me3

Summary

Introduction

From two decades of studies, it is clear that the primary sequence information of DNA can be enhanced by epigenetic modifications. Zeng et al (2016) reported that Lin28A, a paralog of Lin28 that is preferentially expressed in mouse embryos and ESCs before differentiation, can recruit TET1 to DNA and facilitate the conversion of 5mC to 5hmC and demethylation of gene bodies (Tan and Yeo, 2016). More 5hmC is found in gene bodies of active genes, and TET1 is often observed at TSS of genes with high CpG promoters that are marked by the bivalent histone signature of H3K27me3 and H3K4me3.

Results

Conclusion