A nuclear poly(ADP-ribose)-dependent signalosome confers DNA damage-induced IkappaB kinase activation

Mol Cell. 2009 Nov 13;36(3):365-78. doi: 10.1016/j.molcel.2009.09.032.


Upon genotoxic stresses, cells activate IkappaB kinases (IKKs) and the transcription factor NF-kappaB to modulate apoptotic responses. The SUMO-1 ligase PIASy and the kinase ataxia talengiectasia mutated (ATM) have been implicated to SUMOylate and phosphorylate nuclear IKKgamma (NEMO) in a consecutive mode of action, which in turn results in activation of cytoplasmic IKK holocomplexes. However, the nuclear signals and scaffold structures that initiate IKKgamma recruitment and activation are unknown. Here, we show that poly(ADP-ribose)-polymerase-1 (PARP-1) is the DNA proximal regulator, which senses DNA strand breaks and, through poly(ADP-ribose) (PAR) synthesis, assembles IKKgamma, PIASy, and ATM in a dynamic manner. Signalosome formation involves direct protein-protein interactions and binding to ADP-ribose polymers through PAR binding motifs (PARBM). Activated PARP-1 and a PARBM in PIASy are required to trigger IKKgamma SUMOylation, which in turn permits IKK and NF-kappaB activation, as well as NF-kappaB-regulated resistance to apoptosis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Ataxia Telangiectasia Mutated Proteins
  • Blotting, Western
  • Cell Cycle Proteins / metabolism
  • Cell Line, Tumor
  • Cell Nucleus / metabolism
  • Cells, Cultured
  • DNA Damage*
  • DNA-Binding Proteins / metabolism
  • Enzyme Activation
  • Fibroblasts / cytology
  • Fibroblasts / metabolism
  • Fibroblasts / radiation effects
  • Humans
  • I-kappa B Kinase / genetics
  • I-kappa B Kinase / metabolism*
  • Intracellular Signaling Peptides and Proteins / genetics
  • Intracellular Signaling Peptides and Proteins / metabolism
  • Mice
  • Mice, Inbred C57BL
  • Mice, Inbred Strains
  • Mice, Knockout
  • Molecular Sequence Data
  • NF-kappa B / metabolism
  • Poly (ADP-Ribose) Polymerase-1
  • Poly Adenosine Diphosphate Ribose / metabolism*
  • Poly(ADP-ribose) Polymerases / genetics
  • Poly(ADP-ribose) Polymerases / metabolism
  • Protein Binding
  • Protein Inhibitors of Activated STAT / genetics
  • Protein Inhibitors of Activated STAT / metabolism
  • Protein Serine-Threonine Kinases / metabolism
  • Sequence Homology, Amino Acid
  • Signal Transduction*
  • Tumor Suppressor Proteins / metabolism


  • Cell Cycle Proteins
  • DNA-Binding Proteins
  • Intracellular Signaling Peptides and Proteins
  • NEMO protein, mouse
  • NF-kappa B
  • Piasy protein, mouse
  • Protein Inhibitors of Activated STAT
  • Tumor Suppressor Proteins
  • Poly Adenosine Diphosphate Ribose
  • Parp1 protein, mouse
  • Poly (ADP-Ribose) Polymerase-1
  • Poly(ADP-ribose) Polymerases
  • ATM protein, human
  • Ataxia Telangiectasia Mutated Proteins
  • Atm protein, mouse
  • Protein Serine-Threonine Kinases
  • I-kappa B Kinase