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DNA methylation: TET proteins—guardians of CpG islands?
Author(s) -
Williams Kristine,
Christensen Jesper,
Helin Kristian
Publication year - 2012
Publication title -
embo reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.584
H-Index - 184
eISSN - 1469-3178
pISSN - 1469-221X
DOI - 10.1038/embor.2011.233
Subject(s) - dna methylation , biology , rna directed dna methylation , dna demethylation , epigenomics , genetics , epigenetics of physical exercise , epigenetics , gene , gene expression
DNA methylation is involved in key cellular processes, including X‐chromosome inactivation, imprinting and transcriptional silencing of specific genes and repetitive elements. DNA methylation patterns are frequently perturbed in human diseases such as imprinting disorders and cancer. The recent discovery that the three members of the TET protein family can convert 5‐methylcytosine (5mC) into 5‐hydroxymethylcytosine (5hmC) has provided a potential mechanism leading to DNA demethylation. Moreover, the demonstration that TET2 is frequently mutated in haematopoietic tumours suggests that the TET proteins are important regulators of cellular identity. Here, we review the current knowledge regarding the function of the TET proteins, and discuss various mechanisms by which they contribute to transcriptional control. We propose that the TET proteins have an important role in regulating DNA methylation fidelity, and that their inactivation contributes to the DNA hypermethylation phenotype often observed in cancer.