SNIP1 recruits TET2 to regulate c-MYC target genes and cellular DNA damage response
Description
The TET2 DNA dioxygenase regulates gene expression by catalyzing demethylation of 5-methylcytosine, thus epigenetically modulating the genome. TET2 does not contain a sequence-specific DNA binding domain and how it is recruited to specific genomic sites is not fully understood. Here we carried out a mammalian two-hybrid screen and identified multiple transcriptional regulators that potentially interact with TET2. The SMAD nuclear interacting protein 1 (SNIP1) physically interacts with TET2 and bridges TET2 to bind several transcription factors including c-MYC. SNIP1 recruits TET2 to the promoters of c-MYC target genes, including those involved in DNA damage response and cell viability. TET2 protects cells from DNA damage-induced apoptosis in a manner dependent on SNIP1. Our observations uncover a mechanism for targeting TET2 to specific promoters through a ternary interaction with a co-activator and many sequence-specific DNA binding factors. This study also reveals a TET2-SNIP1-c-MYC pathway in mediating DNA damage response, thereby connecting epigenetic control to maintenance of genome stability.