The RAD6 Pathway: Control of DNA Damage Bypass and Mutagenesis by Ubiquitin and SUMO

Tolerance mechanisms against DNA damage allow cells to complete DNA replication in the presence of lesions that would otherwise inhibit the progression of the replication fork. As these bypass systems often operate with reduced fidelity, a tight control over their activity is required to prevent the accumulation of unwanted mutations. In eukaryotes, control of damage tolerance is exerted by the modification of PCNA, an essential regulator of the replication fork, by the small proteins ubiquitin and SUMO.