Cellular response to DNA damage

Reponse Mechanisms

Tolerance of DNA damage Replicative bypass of template damage

Translesion DNA synthesis

Reversal of DNA damage Enzymatic photoreactivation

Repair of O6-alkylguanine, O4-

alkyltimidine

Ligation of DNA strand breaks

Excision of DNA damage Base Excision Repair

Nucleotide Excision Repair

Mismatch Repair

Double strand breaks ligation Single strand annealing

Recombinational Repair

Non-Homologous End Joining

La radiazione Solare può essere distinta in 3 componenti principali a seconda della lunghezza d’onda:ULTRAVIOLETTO (100-400 nanometri) 10%VISIBILE ( 400-750nm.) 45%INFRAROSSO (750-3000nm.) 45%

UV-induced damage

UV-responsive photolyases

Direct reversal (de-alkylating proteins)

Base Excision Repair

Nucleotide Excision Repair

(E.coli)

Nucleotide Excision Repair (Global Genome Repair -Humans)

Nucleotide Excision Repair(Transcription Coupled -Humans)

Common features of GGR & TCR