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The DFF40/CAD endonuclease and its role in apoptosis

P Widłak1

  • 1Department of Experimental and Clinical Radiobiology, Center of Oncology, Gliwice, Poland. widlak@onkol.instonko.gliwice.pl

Acta Biochimica Polonica
|May 9, 2002
PubMed

Insights

DNA Fragmentation Factor 40 (DFF40/CAD) is a key nuclease in apoptosis, causing DNA fragmentation and chromatin condensation. Its activation by caspase-3 leads to double-strand DNA breaks, a hallmark of programmed cell death.

Area of Science:

  • Biochemistry
  • Molecular Biology
  • Cell Biology

Background:

  • Apoptosis is characterized by DNA fragmentation and chromatin condensation.
  • DNA Fragmentation Factor 40 (DFF40), also known as Caspase-activated DNase (CAD), is a primary nuclease involved in this process.

Purpose of the Study:

  • To elucidate the role and mechanism of DFF40/CAD in DNA fragmentation during apoptosis.
  • To understand the substrate specificity and activation of DFF40/CAD.

Main Methods:

  • Biochemical assays to characterize DFF40/CAD activity.
  • Studies on the interaction between DFF40/CAD and its inhibitor DFF45/ICAD.
  • Chromatin analysis to identify cleavage sites.

Main Results:

  • DFF40/CAD is a magnesium-dependent endonuclease that creates double-strand DNA breaks with 3'-hydroxyl ends.
  • Activation occurs via caspase-3 cleavage of the inhibitor DFF45/ICAD.
  • The nuclease preferentially targets internucleosomal linker DNA but can also mediate large-scale DNA fragmentation.

Conclusions:

  • DFF40/CAD plays a crucial role in the DNA fragmentation observed during apoptosis.
  • DFF40/CAD-mediated DNA cleavage contributes to chromatin condensation, a key apoptotic event.

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