The C. elegans apoptotic nuclease NUC-1 is related in sequence and activity to mammalian DNase II

Gene. 2000 Jul 11;252(1-2):147-54. doi: 10.1016/s0378-1119(00)00213-4.


The Caenorhabditis elegans nuc-1 gene has previously been implicated in programmed cell death due to the presence of persistent undegraded apoptotic DNA in nuc-1 mutant animals. In this report, we describe the cloning and characterization of nuc-1, which encodes an acidic nuclease with significant sequence similarity to mammalian DNase II. Database searches performed with human DNase II protein sequence revealed a significant similarity with the predicted C. elegans C07B5.5 ORF. Subsequent analysis of crude C. elegans protein extracts revealed that wild-type animals contained a potent endonuclease activity with a cleavage preference similar to DNase II, while nuc-1 mutant worms demonstrated a marked reduction in this nuclease activity. Sequence analysis of C07B5.5 DNA and mRNA also revealed that nuc-1(e1392), but not wild-type animals contained a nonsense mutation within the CO7B5.5 coding region. Furthermore, nuc-1 transgenic lines carrying the wild-type C07B5.5 locus demonstrated a complete complementation of the nuc-1 mutant phenotype. Our results therefore provide compelling evidence that the C07B5.5 gene encodes the NUC-1 apoptotic nuclease and that this nuclease is related in sequence and activity to DNase II.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Apoptosis*
  • Base Sequence
  • Caenorhabditis elegans / enzymology
  • Caenorhabditis elegans / genetics*
  • Cloning, Molecular
  • Cosmids / genetics
  • DNA, Recombinant / genetics
  • Endodeoxyribonucleases / deficiency
  • Endodeoxyribonucleases / genetics*
  • Endodeoxyribonucleases / metabolism
  • Genetic Complementation Test
  • Humans
  • Molecular Sequence Data
  • Mutation
  • Open Reading Frames / genetics
  • Sequence Alignment
  • Sequence Homology, Amino Acid
  • Sequence Homology, Nucleic Acid


  • DNA, Recombinant
  • Endodeoxyribonucleases
  • deoxyribonuclease II