title: ATM-dependent activation of the gene encoding MAP kinase phosphatase 5 by radiomimetic DNA damage.
abstract: Cellular responses to DNA damage are mediated by an extensive network of signaling pathways. The ATM protein kinase is a master regulator of the response to double-strand breaks (DSBs), the most cytotoxic DNA lesion caused by ionizing radiation. ATM is the protein missing or inactive in patients with the pleiotropic genetic disorder ataxia-telangiectasia (A-T). A major response to DNA damage is altered expression of numerous genes. While studying gene expression in control and A-T cells following treatment with the radiomimetic chemical neocarzinostatin (NCS), we identified an expressed sequence tag that represented a gene that was induced by DSBs in an ATM-dependent manner. The corresponding cDNA encoded a dual specificity phosphatase of the MAP kinase phosphatase family, MKP-5. MKP-5 dephosphorylates and inactivates the stress-activated MAP kinases JNK and p38. The phosphorylation-dephosphorylation cycle of JNK and p38 by NCS was attenuated in A-T cells. Thus, ATM modulates this cycle in response to DSBs. These results further highlight ATM as a link between the DNA damage response and major signaling pathways involved in proliferative and apoptotic processes.
authors.affiliation: The David and Inez Myers Laboratory for Genetic Research, Department of Human Genetics and Molecular Medicine, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel.
authors.forename: Anat
authors.initials: A
authors.lastname: Bar-Shira
authors.forename: Sharon
authors.initials: S
authors.lastname: Rashi-Elkeles
authors.forename: Liat
authors.initials: L
authors.lastname: Zlochover
authors.forename: Lilach
authors.initials: L
authors.lastname: Moyal
authors.forename: Nechama I
authors.initials: NI
authors.lastname: Smorodinsky
authors.forename: Rony
authors.initials: R
authors.lastname: Seger
authors.forename: Yosef
authors.initials: Y
authors.lastname: Shiloh
mesh_terms: D001260:Ataxia Telangiectasia / Q000235:genetics / Q000378:metabolism; D064007:Ataxia Telangiectasia Mutated Proteins; D018797:Cell Cycle Proteins; D002460:Cell Line; D004249:DNA Damage; D004268:DNA-Binding Proteins; D054637:Dual-Specificity Phosphatases; D004789:Enzyme Activation; D017353:Gene Deletion; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D048031:JNK Mitogen-Activated Protein Kinases; D007700:Kinetics; D054639:Mitogen-Activated Protein Kinase Phosphatases; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000502:physiology*; D017027:Protein Tyrosine Phosphatases / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000096:biosynthesis; D011839:Radiation, Ionizing; D015533:Transcriptional Activation; D025521:Tumor Suppressor Proteins; D009353:Zinostatin / Q000494:pharmacology*; D048051:p38 Mitogen-Activated Protein Kinases
chemical_list: D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D047908:Intracellular Signaling Peptides and Proteins; D012333:RNA, Messenger; D025521:Tumor Suppressor Proteins; D009353:Zinostatin; C576324:ATM protein, human; D064007:Ataxia Telangiectasia Mutated Proteins; D017346:Protein Serine-Threonine Kinases; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; C120407:DUSP10 protein, human; D054639:Mitogen-Activated Protein Kinase Phosphatases; D054637:Dual-Specificity Phosphatases; D017027:Protein Tyrosine Phosphatases