What is the role of Tet in gene transcription?
What is the role of Tet in gene transcription?
The TET enzymes are a family of ten-eleven translocation (TET) methylcytosine dioxygenases. They are instrumental in DNA demethylation. 5-Methylcytosine (see first Figure) is a methylated form of the DNA base cytosine (C) that often regulates gene transcription and has several other functions in the genome.
How many TET enzymes are there?
three TET enzymes
TET3 is expressed in the oocyte and the zygote; all three TET proteins are expressed in blastocysts; TET1 and TET2 are expressed in embryonic stem (ES) cells; and TET2 and TET3 are expressed ubiquitously in differentiated cells (3, 4). The three TET enzymes appear to have overlapping but distinct targets in the genome.
What happens in DNA demethylation?
DNA demethylation is the process of removal of a methyl group from cytosines. DNA demethylation can be passive or active. The passive process takes place in the absence of methylation of newly synthesized DNA strands by DNMT1 during several replication rounds – for example, upon 5-azacytidine treatment [23].
What is Tet1 and Tet2?
We show that Tet1 and Tet2 have distinct roles in mouse ES cells: Tet1 primarily regulates 5hmC levels at gene promoters and transcription start sites, whereas Tet2 mainly regulates 5hmC levels in gene bodies and exon boundaries of highly-expressed genes and exons respectively.
Where are TET enzymes found?
embryonic stem cells
TET1/2 are found in embryonic stem cells, while TET3 is found in the germ line (Ito et al., 2010). The significance of these differences, and the mechanisms of how TETs are regulated remain largely unknown. The potential biological roles of these enzymes are becoming clear.
How does demethylation happen?
DNA demethylation can occur by an active process at the site of a 5mC in a DNA sequence or, in replicating cells, by preventing addition of methyl groups to DNA so that the replicated DNA will largely have cytosine in the DNA sequence (5mC will be diluted out).
What is the purpose of demethylation?
Active DNA demethylation refers to an enzymatic process that removes or modifies the methyl group from 5mC. By contrast, passive DNA demethylation refers to loss of 5mC during successive rounds of replication in the absence of functional DNA methylation maintenance machinery.
What is TET2 gene?
The TET2 gene provides instructions for making a protein whose function is unknown. Based on the function of similar proteins, researchers believe the TET2 protein is involved in regulating the process of transcription, which is the first step in protein production.
