Regulation of 5-Hydroxymethylcytosine Distribution by the TET Enzymes

Abstract

5-Hydroxymethylcytosine (5-hmC) has a critical role in the epigenetic regulation of many cellular processes, including differentiation, cytokine responses, and memory formation. This modified base is generated by the TET enzymes through oxidizing 5-methylcytosine and can be further oxidized to 5-formylcytosine and 5-carboxylcytosine. The level and distribution of 5-hmC in the genome is tightly controlled through transcription of TET genes, post-translational modifications on the TET enzymes, and various interacting partners of TET enzymes. Deregulation of 5-hmC is often found in pathological conditions and plays crucial roles in disease progression. This chapter will discuss recent findings regarding 5-hmC functions, TET proteins, and their gene regulations, as well as their relationships to cancer.