Induction of a pro-apoptotic ATM-NF-kappaB pathway and its repression by ATR in response to replication stress.
The transcription factor NF-kappaB has critical functions in biologic responses to genotoxic stimuli. Activation of NF-kappaB in response to DNA double strand break (DSB) inducers can be mediated by ATM (ataxia telangiectasia mutated)-dependent phosphorylation of NEMO (NF-kappaB essential modulator). Here, we show that the replication stress inducers hydroxyurea (HU) and aphidicolin also activate this ATM-dependent signalling pathway. We further show that ATR (ATM- and Rad3-related) interacts with NEMO but surprisingly does not cause NEMO phosphorylation. Consequently, ATR represses NF-kappaB activation induced by replication stress. Reduction or increase of ATR expression by RNA interference or overexpression increased or reduced ATM-NEMO association and NF-kappaB activation induced by HU. Apoptosis gene expression and chromatin immunoprecipitation analyses indicated that HU and the DSB inducer etoposide caused complex patterns of NF-kappaB-dependent pro- and antiapoptotic gene expression with the overall outcome for the former being pro-apoptotic, whereas the latter antiapoptotic. Thus, replication stress and DSB inducers activate NF-kappaB through a conserved pathway with opposite biologic outcomes, and ATR antagonizes ATM function at least in part by competing for NEMO association.
Wu
Zhao-Hui
ZH
Department of Pharmacology, University of Wisconsin, Madison, WI 53706, USA.
Miyamoto
Shigeki
S
D000818:Animals; D016590:Aphidicolin / Q000494:pharmacology; D017209:Apoptosis; D064007:Ataxia Telangiectasia Mutated Proteins; D018797:Cell Cycle Proteins / Q000378:metabolism*; D002460:Cell Line; D004261:DNA Replication / Q000187:drug effects; D004268:DNA-Binding Proteins / Q000378:metabolism*; D006801:Humans; D006918:Hydroxyurea / Q000494:pharmacology; D051550:I-kappa B Kinase / Q000378:metabolism; D047908:Intracellular Signaling Peptides and Proteins / Q000737:chemistry / Q000378:metabolism; D051379:Mice; D016328:NF-kappa B / Q000378:metabolism*; D019384:Nucleic Acid Synthesis Inhibitors / Q000494:pharmacology; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D015398:Signal Transduction; D025841:Small Ubiquitin-Related Modifier Proteins / Q000378:metabolism; D025521:Tumor Suppressor Proteins / Q000378:metabolism*
D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D047908:Intracellular Signaling Peptides and Proteins; D016328:NF-kappa B; D019384:Nucleic Acid Synthesis Inhibitors; D025841:Small Ubiquitin-Related Modifier Proteins; D025521:Tumor Suppressor Proteins; D016590:Aphidicolin; C576324:ATM protein, human; D064007:Ataxia Telangiectasia Mutated Proteins; C576325:Atm protein, mouse; D017346:Protein Serine-Threonine Kinases; D051550:I-kappa B Kinase; D006918:Hydroxyurea