5-methylcytosine catabolic process

Definition

Target type: biologicalprocess

The chemical reactions and pathways resulting in the breakdown of 5-methylcytosine, a methylated base of DNA. [GOC:go_curators]

5-Methylcytosine catabolic process is the breakdown of 5-methylcytosine (5mC), a modified base found in DNA, into its constituent components. This process is essential for DNA demethylation, a crucial regulatory mechanism involved in various cellular processes, including development, differentiation, and disease.

The catabolism of 5mC is initiated by the enzyme thymine DNA glycosylase (TDG), which removes 5mC from the DNA backbone. TDG recognizes 5mC as a damaged base and excises it, creating an abasic site. This site is then processed by the base excision repair (BER) pathway, which removes the abasic site and inserts a new cytosine base, effectively converting 5mC to cytosine.

The BER pathway involves a series of enzymes, including apurinic/apyrimidinic endonuclease 1 (APE1), DNA polymerase beta (Pol beta), and DNA ligase. APE1 cleaves the DNA backbone at the abasic site, creating a single-strand break. Pol beta then inserts a new cytosine base opposite the abasic site, and DNA ligase seals the break, restoring the DNA strand to its original sequence.

In addition to the BER pathway, other pathways have been implicated in 5mC catabolism, including the translesion synthesis pathway and the mismatch repair pathway. These pathways play a role in repairing DNA damage and maintaining genome integrity.

5-Methylcytosine catabolism is a highly regulated process, and its dysregulation can lead to various pathological conditions, including cancer, neurodevelopmental disorders, and autoimmune diseases. The understanding of 5mC catabolic process has important implications for the development of novel therapeutic strategies targeting epigenetic modifications in disease.'
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Proteins (1)

Compounds (4)