The cytotoxic T lymphocyte protease granzyme A cleaves and inactivates poly(adenosine 5'-diphosphate-ribose) polymerase-1

Blood. 2009 Aug 6;114(6):1205-16. doi: 10.1182/blood-2008-12-195768. Epub 2009 Jun 8.


Granzyme A (GzmA) in killer cells induces caspase-independent programmed cell death. In this study, we show that GzmA cleaves the DNA damage sensor poly(adenosine 5'-diphosphate-ribose) polymerase-1 (PARP-1) after Lys(498) in its automodification domain, separating the DNA binding domain from the catalytic domain, which interferes with repair of GzmA-induced DNA damage and enhances susceptibility to GzmA-mediated death. Overexpressing K498A PARP-1 reduces GzmA-mediated death and drives dying cells to necrosis rather than apoptosis. Conversely, inhibiting or genetically disrupting PARP-1 enhances cell vulnerability. The N-terminal GzmA cleavage fragment of PARP-1 acts as a PARP-1 dominant negative, binding to DNA and blocking DNA repair. Disrupting PARP-1, which is also a caspase target, is therefore required for efficient apoptosis by both caspase-independent and caspase-dependent pathways.

Publication types

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

MeSH terms

  • Amino Acid Substitution
  • Apoptosis / genetics
  • Apoptosis / immunology*
  • CD8-Positive T-Lymphocytes / enzymology
  • CD8-Positive T-Lymphocytes / immunology*
  • Caspases / genetics
  • Caspases / immunology
  • Caspases / metabolism
  • DNA Damage / immunology*
  • DNA Repair / genetics
  • DNA Repair / immunology*
  • Gene Expression
  • Granzymes / genetics
  • Granzymes / immunology*
  • Granzymes / metabolism
  • HeLa Cells
  • Humans
  • K562 Cells
  • Mutation, Missense
  • Poly (ADP-Ribose) Polymerase-1
  • Poly(ADP-ribose) Polymerases / genetics
  • Poly(ADP-ribose) Polymerases / immunology*
  • Poly(ADP-ribose) Polymerases / metabolism
  • Protein Structure, Tertiary / physiology


  • PARP1 protein, human
  • Poly (ADP-Ribose) Polymerase-1
  • Poly(ADP-ribose) Polymerases
  • Granzymes
  • Caspases