Activation of multiple DNA repair pathways by sub-nuclear damage induction methods

J Cell Sci. 2007 Aug 1;120(Pt 15):2731-40. doi: 10.1242/jcs.004523.


Live cell studies of DNA repair mechanisms are greatly enhanced by new developments in real-time visualization of repair factors in living cells. Combined with recent advances in local sub-nuclear DNA damage induction procedures these methods have yielded detailed information on the dynamics of damage recognition and repair. Here we analyze and discuss the various types of DNA damage induced in cells by three different local damage induction methods: pulsed 800 nm laser irradiation, Hoechst 33342 treatment combined with 405 nm laser irradiation and UV-C (266 nm) laser irradiation. A wide variety of damage was detected with the first two methods, including pyrimidine dimers and single- and double-strand breaks. However, many aspects of the cellular response to presensitization by Hoechst 33342 and subsequent 405 nm irradiation were aberrant from those to every other DNA damaging method described here or in the literature. Whereas, application of low-dose 266 nm laser irradiation induced only UV-specific DNA photo-lesions allowing the study of the UV-C-induced DNA damage response in a user-defined area in cultured cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Signal Transducing
  • Cell Cycle Proteins
  • Cell Line
  • DNA Breaks, Double-Stranded*
  • DNA Breaks, Single-Stranded*
  • DNA Helicases
  • DNA Repair*
  • DNA-Binding Proteins / isolation & purification
  • DNA-Binding Proteins / metabolism
  • Dose-Response Relationship, Radiation
  • Humans
  • Nuclear Proteins / isolation & purification
  • Nuclear Proteins / metabolism
  • Proliferating Cell Nuclear Antigen / isolation & purification
  • Proliferating Cell Nuclear Antigen / metabolism
  • Pyrimidine Dimers / isolation & purification
  • Pyrimidine Dimers / metabolism
  • Trans-Activators / isolation & purification
  • Trans-Activators / metabolism
  • Ultraviolet Rays*
  • Xeroderma Pigmentosum Group A Protein / isolation & purification
  • Xeroderma Pigmentosum Group A Protein / metabolism


  • Adaptor Proteins, Signal Transducing
  • Cell Cycle Proteins
  • DNA-Binding Proteins
  • MDC1 protein, human
  • Nuclear Proteins
  • Proliferating Cell Nuclear Antigen
  • Pyrimidine Dimers
  • Trans-Activators
  • XPA protein, human
  • Xeroderma Pigmentosum Group A Protein
  • XPC protein, human
  • DNA Helicases
  • RAD54L protein, human