title: Recurrent initiation: a mechanism for triggering p53 pulses in response to DNA damage.
abstract: DNA damage initiates a series of p53 pulses. Although much is known about the interactions surrounding p53, little is known about which interactions contribute to p53's dynamical behavior. The simplest explanation is that these pulses are oscillations intrinsic to the p53/Mdm2 negative feedback loop. Here we present evidence that this simple mechanism is insufficient to explain p53 pulses; we show that p53 pulses are externally driven by pulses in the upstream signaling kinases, ATM and Chk2, and that the negative feedback between p53 and ATM, via Wip1, is essential for maintaining the uniform shape of p53 pulses. We propose that p53 pulses result from repeated initiation by ATM, which is reactivated by persistent DNA damage. Our study emphasizes the importance of collecting quantitative dynamic information at high temporal resolution for understanding the regulation of signaling pathways and opens new ways to manipulate p53 pulses to ask questions about their function in response to DNA damage.
authors.affiliation: Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Eric
authors.initials: E
authors.lastname: Batchelor
authors.forename: Caroline S
authors.initials: CS
authors.lastname: Mock
authors.forename: Irun
authors.initials: I
authors.lastname: Bhan
authors.forename: Alexander
authors.initials: A
authors.lastname: Loewer
authors.forename: Galit
authors.initials: G
authors.lastname: Lahav
mesh_terms: D000818:Animals; D064007:Ataxia Telangiectasia Mutated Proteins; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D045744:Cell Line, Tumor; D064447:Checkpoint Kinase 2; D004249:DNA Damage; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D005720:Gamma Rays; D006801:Humans; D007093:Imidazoles / Q000378:metabolism; D008433:Mathematics; D008962:Models, Theoretical; D010749:Phosphoprotein Phosphatases / Q000235:genetics / Q000378:metabolism*; D010879:Piperazines / Q000378:metabolism; D000071636:Protein Phosphatase 2C; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism; D051736:Proto-Oncogene Proteins c-mdm2 / Q000235:genetics / Q000378:metabolism; D034622:RNA Interference; D015398:Signal Transduction / Q000502:physiology*; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism*; D025521:Tumor Suppressor Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D007093:Imidazoles; D010879:Piperazines; C495901:TP53 protein, human; D016159:Tumor Suppressor Protein p53; D025521:Tumor Suppressor Proteins; C482205:nutlin 3; D051736:Proto-Oncogene Proteins c-mdm2; D064447:Checkpoint Kinase 2; C576324:ATM protein, human; D064007:Ataxia Telangiectasia Mutated Proteins; C578634:CHEK2 protein, human; D017346:Protein Serine-Threonine Kinases; C000607458:PPM1D protein, human; D010749:Phosphoprotein Phosphatases; D000071636:Protein Phosphatase 2C