The nucleotide excision repair pathway is required for UV-C-induced apoptosis in Caenorhabditis elegans

Cell Death Differ. 2007 Jun;14(6):1129-38. doi: 10.1038/sj.cdd.4402115. Epub 2007 Mar 9.


Ultraviolet (UV) radiation is a mutagen of major clinical importance in humans. UV-induced damage activates multiple signaling pathways, which initiate DNA repair, cell cycle arrest and apoptosis. To better understand these pathways, we studied the responses to UV-C light (254 nm) of germ cells in Caenorhabditis elegans. We found that UV activates the same cellular responses in worms as in mammalian cells. Both UV-induced apoptosis and cell cycle arrest were completely dependent on the p53 homolog CEP-1, the checkpoint proteins HUS-1 and CLK-2, and the checkpoint kinases CHK-2 and ATL-1 (the C. elegans homolog of ataxia telangiectasia and Rad3-related); ATM-1 (ataxia telangiectasia mutated-1) was also required, but only at low irradiation doses. Importantly, mutation of genes encoding nucleotide excision repair pathway components severely disrupted both apoptosis and cell cycle arrest, suggesting that these genes not only participate in repair, but also signal the presence of damage to downstream components of the UV response pathway that we delineate here. Our study suggests that whereas DNA damage response pathways are conserved in metazoans in their general outline, there is significant evolution in the relative importance of individual checkpoint genes in the response to specific types of DNA damage.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis / genetics
  • Apoptosis / physiology
  • Apoptosis / radiation effects*
  • Ataxia Telangiectasia Mutated Proteins
  • Caenorhabditis elegans / genetics
  • Caenorhabditis elegans / metabolism
  • Caenorhabditis elegans / radiation effects*
  • Caenorhabditis elegans Proteins / genetics
  • Caenorhabditis elegans Proteins / metabolism
  • Cell Cycle / genetics
  • Cell Cycle / physiology
  • Cell Cycle / radiation effects
  • Cell Cycle Proteins / genetics
  • Cell Cycle Proteins / metabolism
  • Checkpoint Kinase 2
  • Chromosomal Proteins, Non-Histone / genetics
  • Chromosomal Proteins, Non-Histone / metabolism
  • DNA Damage
  • DNA Repair*
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism
  • Immunohistochemistry
  • Models, Biological
  • Mutation / genetics
  • Mutation / physiology
  • Protein-Serine-Threonine Kinases / genetics
  • Protein-Serine-Threonine Kinases / metabolism
  • Tumor Suppressor Proteins / genetics
  • Tumor Suppressor Proteins / metabolism
  • Ultraviolet Rays*


  • Caenorhabditis elegans Proteins
  • Cell Cycle Proteins
  • Chromosomal Proteins, Non-Histone
  • DNA-Binding Proteins
  • Tumor Suppressor Proteins
  • Checkpoint Kinase 2
  • ATM protein, human
  • Ataxia Telangiectasia Mutated Proteins
  • CHEK2 protein, human
  • Protein-Serine-Threonine Kinases