The C. elegans apoptotic nuclease NUC-1 is related in sequence and activity to mammalian DNase II.
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.
Lyon
C J
CJ
Department of Molecular, Cell and Developmental Biology, University of California, 90995-1606, Los Angeles, CA, USA.
Evans
C J
CJ
Bill
B R
BR
Otsuka
A J
AJ
Aguilera
R J
RJ
D000595:Amino Acid Sequence; D000818:Animals; D017209:Apoptosis; D001483:Base Sequence; D017173:Caenorhabditis elegans / Q000201:enzymology / Q000235:genetics*; D003001:Cloning, Molecular; D003360:Cosmids / Q000235:genetics; D004274:DNA, Recombinant / Q000235:genetics; D004706:Endodeoxyribonucleases / Q000172:deficiency / Q000235:genetics* / Q000378:metabolism; D005816:Genetic Complementation Test; D006801:Humans; D008969:Molecular Sequence Data; D009154:Mutation; D016366:Open Reading Frames / Q000235:genetics; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid
D004274:DNA, Recombinant; D004706:Endodeoxyribonucleases; C019329:deoxyribonuclease II