DNA damage
DNA is susceptible to a variety of chemical modifications that may damage it.
- chemicals, viruses, and ionizing radiation can all cause damage to DNA
- oxidation, nitrosylation, and alkylation of the DNA heterocyclic base
- phosphodiester linkage break
- 10 4 – 10 5 events per cell per day
Cells detect damage to DNA and attempt repairs
- DNA damage response (DDR) can be:
- nucleotide excision repair (NER)
- base excision repair (BER), and
- non-homologous end-joining (NHEJ)