Cellular response to DNA damage Reponse Mechanisms Tolerance of DNA damage Replicative bypass of template damage Translesion DNA synthesis Reversal.

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