Translesion synthesis in mammalian cells

Exp Cell Res. 2006 Aug 15;312(14):2673-6. doi: 10.1016/j.yexcr.2006.06.010. Epub 2006 Jun 20.


DNA damage blocks the progression of the replication fork. In order to circumvent the damaged bases, cells employ specialized low stringency DNA polymerases, which are able to carry out translesion synthesis (TLS) past different types of damage. The five polymerases used in TLS in human cells have different substrate specificities, enabling them to deal with many different types of damaged bases. PCNA plays a central role in recruiting the TLS polymerases and effecting the polymerase switch from replicative to TLS polymerase. When the fork is blocked PCNA gets ubiquitinated. This increases its affinity for the TLS polymerases, which all have novel ubiquitin-binding motifs, thereby facilitating their engagement at the stalled fork to effect TLS.

Publication types

  • Review

MeSH terms

  • Animals
  • DNA Repair*
  • DNA Replication*
  • DNA-Directed DNA Polymerase / physiology*
  • Humans
  • Models, Biological
  • Proliferating Cell Nuclear Antigen / physiology*
  • Ubiquitin / metabolism
  • Ultraviolet Rays


  • Proliferating Cell Nuclear Antigen
  • Ubiquitin
  • DNA-Directed DNA Polymerase