Ubiquitin-dependent regulation of translesion polymerases.
In response to DNA damage, TLS (translesion synthesis) allows replicative bypass of various DNA lesions, which stall normal replication. TLS is achieved by low-fidelity polymerases harbouring less stringent active sites. In humans, Y-family polymerases together with Pol zeta (polymerase zeta) are responsible for TLS across different types of damage. Protein-protein interaction contributes significantly to the regulation of TLS. REV1 plays a central role in TLS because it interacts with all other Y-family members and Pol zeta. Ubiquitin-dependent regulatory mechanisms also play important roles in TLS. Ubiquitin-binding domains have been found in TLS polymerases and they might be required for TLS activity. Mono-ubiquitination of PCNA (proliferating-cell nuclear antigen), the central scaffold of TLS polymerases, is thought to promote TLS. In addition, both non-proteolytic and proteolytic polyubiquitination of PCNA and TLS polymerases has been demonstrated. Owing to their low fidelity, the recruitment of TLS polymerases is strictly restricted to stalled replication forks.
Chun
Abel C S
AC
Department of Biochemistry, The University of Hong Kong, 21 Sassoon Road, Pokfulam, Hong Kong.
Jin
Dong-Yan
DY
D000818:Animals; D002453:Cell Cycle / Q000502:physiology; D004249:DNA Damage; D004260:DNA Repair; D004261:DNA Replication; D004259:DNA-Directed DNA Polymerase / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D018809:Proliferating Cell Nuclear Antigen / Q000235:genetics / Q000378:metabolism; D025801:Ubiquitin / Q000378:metabolism*; D054875:Ubiquitination
D007527:Isoenzymes; D018809:Proliferating Cell Nuclear Antigen; D025801:Ubiquitin; D004259:DNA-Directed DNA Polymerase