AIF-mediated caspase-independent necroptosis requires ATM and DNA-PK-induced histone H2AX Ser139 phosphorylation

Cell Death Dis. 2012 Sep 13;3(9):e390. doi: 10.1038/cddis.2012.120.

Abstract

The alkylating DNA-damage agent N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) induces a form of caspase-independent necroptosis implicating the mitochondrial flavoprotein apoptosis-inducing factor (AIF). Following the activation of PARP-1 (poly(ADP-ribose) polymerase-1), calpains, BID (BH3 interacting domain death agonist), and BAX (Bcl-2-associated X protein), the apoptogenic form of AIF (tAIF) is translocated to the nucleus where, associated with Ser139-phosphorylated histone H2AX (γH2AX), it creates a DNA-degrading complex that provokes chromatinolysis and cell death by necroptosis. The generation of γH2AX is crucial for this form of cell death, as mutation of H2AX Ser139 to Ala or genetic ablation of H2AX abolish both chromatinolysis and necroptosis. On the contrary, reintroduction of H2AX-wt or the phosphomimetic H2AX mutant (H2AX-S139E) into H2AX(-/-) cells resensitizes to MNNG-triggered necroptosis. Employing a pharmacological approach and gene knockout cells, we also demonstrate in this paper that the phosphatidylinositol-3-OH kinase-related kinases (PIKKs) ATM (ataxia telangiectasia mutated) and DNA-dependent protein kinase (DNA-PK) mediate γH2AX generation and, consequently, MNNG-induced necroptosis. By contrast, H2AX phosphorylation is not regulated by ATR or other H2AX-related kinases, such as JNK. Interestingly, ATM and DNA-PK phosphorylate H2AX at Ser139 in a synergistic manner with different kinetics of activation. Early after MNNG treatment, ATM generates γH2AX. Further, DNA-PK contributes to H2AX Ser139 phosphorylation. In revealing the pivotal role of PIKKs in MNNG-induced cell death, our data uncover a milestone in the mechanisms regulating AIF-mediated caspase-independent necroptosis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis / drug effects
  • Apoptosis Inducing Factor / metabolism*
  • Ataxia Telangiectasia Mutated Proteins
  • Caspases / metabolism*
  • Cell Cycle Proteins / antagonists & inhibitors
  • Cell Cycle Proteins / metabolism*
  • Cell Line
  • Chromatin / metabolism
  • DNA Breaks, Double-Stranded / drug effects
  • DNA-Activated Protein Kinase / antagonists & inhibitors
  • DNA-Activated Protein Kinase / metabolism*
  • DNA-Binding Proteins / antagonists & inhibitors
  • DNA-Binding Proteins / metabolism*
  • GTPase-Activating Proteins / genetics
  • GTPase-Activating Proteins / metabolism
  • Histones / genetics
  • Histones / metabolism*
  • Kinetics
  • Methylnitronitrosoguanidine / pharmacology
  • Mice
  • Phosphatidylinositol 3-Kinases / metabolism
  • Phosphorylation
  • Protein-Serine-Threonine Kinases / antagonists & inhibitors
  • Protein-Serine-Threonine Kinases / metabolism*
  • Tumor Suppressor Proteins / antagonists & inhibitors
  • Tumor Suppressor Proteins / metabolism*

Substances

  • Apoptosis Inducing Factor
  • Cell Cycle Proteins
  • Chromatin
  • DNA-Binding Proteins
  • GTPase-Activating Proteins
  • H2AX protein, mouse
  • Histones
  • Ralbp1 protein, mouse
  • Tumor Suppressor Proteins
  • Methylnitronitrosoguanidine
  • Phosphatidylinositol 3-Kinases
  • Ataxia Telangiectasia Mutated Proteins
  • Atm protein, mouse
  • DNA-Activated Protein Kinase
  • Protein-Serine-Threonine Kinases
  • Caspases