Selective oxidation of 5-methylcytosine by TET-family proteins
The present invention provides for novel methods for regulating and detecting the cytosine methylation status of DNA. The invention is based upon identification of a novel and surprising catalytic activity for the family of TET proteins, namely TET1, TET2, TET3, and CXXC4. The novel activity is related to the enzymes being capable of converting the cytosine nucleotide 5-methylcytosine into 5-hydroxymethylcytosine by hydroxylation.
1. A kit for detecting a naturally occurring 5-hydroxymethylcytosine nucleotide in a biological sample comprising DNA of mammalian cells, the kit comprising: (1) an antibody or a binding portion thereof that binds to the naturally occurring 5-hydroxymethylcytosine nucleotide, (2) a catalytically active TET family enzyme, a functional TET family derivative, a TET family catalytically active fragment thereof, or combination thereof; and (3) packaging materials and instructions to extract a DNA sample from the biological sample.
2. The method of claim 1 , wherein the antibody or a binding portion thereof that binds to the naturally occurring 5-hydroxymethylcytosine nucleotide is labeled.