Microinjection of Micrococcus luteus UV-endonuclease restores UV-induced unscheduled DNA synthesis in cells of 9 xeroderma pigmentosum complementation groups

Mutat Res. Jun-Jul 1985;150(1-2):99-105. doi: 10.1016/0027-5107(85)90106-x.


The UV-induced unscheduled DNA synthesis (UDS) in cultured cells of excision-deficient xeroderma pigmentosum (XP) complementation groups A through I was assayed after injection of Micrococcus luteus UV-endonuclease using glass microneedles. In all complementation groups a restoration of the UV-induced UDS, in some cells to the repair-proficient human level, was observed. Another prokaryotic DNA-repair enzyme, T4 endonuclease V, restored the UV-induced UDS in a similar way after microinjection into XP cells. Since both enzymes specifically catalyse only the incision of UV-irradiated DNA, we conclude that this activity is impaired in cells of all 9 excision-deficient XP complementation groups tested.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cells, Cultured
  • DNA / biosynthesis
  • DNA / radiation effects*
  • DNA Repair*
  • Endodeoxyribonucleases / administration & dosage
  • Genetic Complementation Test
  • Humans
  • Micrococcus / enzymology
  • Microinjections
  • Multienzyme Complexes / administration & dosage*
  • N-Glycosyl Hydrolases*
  • Ultraviolet Rays
  • Xeroderma Pigmentosum / enzymology
  • Xeroderma Pigmentosum / genetics*


  • Multienzyme Complexes
  • UV endonuclease
  • DNA
  • Endodeoxyribonucleases
  • deoxyribonuclease V
  • N-Glycosyl Hydrolases