TET3
Description
The TET3 (tet methylcytosine dioxygenase 3) is a protein-coding gene located on chromosome 2.
Tet methylcytosine dioxygenase 3 is a protein that in humans is encoded by the TET3 gene.
== Function == Tet3 and its respective protein TET 3 are members of the TET (ten-eleven-translocation) family of genes and proteins that play a role in DNA demethylation. DNA demethylation is the removal of suppressive methyl groups from the cytosine of DNA. Demethylating the DNA and removing these markers is associated with increased transcription. Since DNA methylation is a relatively strong and stable marker it is not often removed. However, there are important points in an organism’s life when these marks benefit from being removed so that certain genes can be accessed and transcribed. One of which is right after an egg and sperm have come together to form a zygote. The methylation marks from the parent cells must be removed so that certain genes can be accessed and transcribed for the zygote to mature into a fully grown organism. Tet3 plays an important role here. The TET3 protein works to demethylate the genome of the fertilized zygote to allow it to grow into a fully developed organism. It does this by starting a series of oxidation reactions that convert the methylated cytosine on the DNA from 5-methyl cytosine (5mC) into 5-hydroxymethylcytosine (5hmC).
Dioxygenase that catalyzes the conversion of the modified genomic base 5-methylcytosine (5mC) into 5-hydroxymethylcytosine (5hmC) and plays a key role in epigenetic chromatin reprogramming in the zygote following fertilization (PubMed:31928709). Also mediates subsequent conversion of 5hmC into 5-formylcytosine (5fC), and conversion of 5fC to 5-carboxylcytosine (5caC). Conversion of 5mC into 5hmC, 5fC and 5caC probably constitutes the first step in cytosine demethylation (By similarity). Selectively binds to the promoter region of target genes and contributes to regulate the expression of numerous developmental genes (PubMed:23217707). In zygotes, DNA demethylation occurs selectively in the paternal pronucleus before the first cell division, while the adjacent maternal pronucleus and certain paternally-imprinted loci are protected from this process. Participates in DNA demethylation in the paternal pronucleus by mediating conversion of 5mC into 5hmC, 5fC and 5caC. Does not mediate DNA demethylation of maternal pronucleus because of the presence of DPPA3/PGC7 on maternal chromatin that prevents TET3-binding to chromatin (By similarity). In addition to its role in DNA demethylation, also involved in the recruitment of the O-GlcNAc transferase OGT to CpG-rich transcription start sites of active genes, thereby promoting histone H2B GlcNAcylation by OGT (PubMed:23353889). Binds preferentially to DNA containing cytidine-phosphate-guanosine (CpG) dinucleotides over CpH (H=A, T, and C), hemimethylated-CpG and hemimethylated-hydroxymethyl- CpG (PubMed:29276034). {ECO:0000250|UniProtKB:Q8BG87, ECO:0000269|PubMed:23217707, ECO:0000269|PubMed:23353889, ECO:0000269|PubMed:29276034, ECO:0000269|PubMed:31928709}
TET3 is also known as BEFAHRS, hCG_40738.
