title: TAO kinases mediate activation of p38 in response to DNA damage.
abstract: Thousand and one amino acid (TAO) kinases are Ste20p-related MAP kinase kinase kinases (MAP3Ks) that activate p38 MAPK. Here we show that the TAO kinases mediate the activation of p38 in response to various genotoxic stimuli. TAO kinases are activated acutely by ionizing radiation, ultraviolet radiation, and hydroxyurea. Full-length and truncated fragments of dominant negative TAOs inhibit the activation of p38 by DNA damage. Inhibition of TAO expression by siRNA also decreases p38 activation by these agents. Cells in which TAO kinases have been knocked down are less capable of engaging the DNA damage-induced G2/M checkpoint and display increased sensitivity to IR. The DNA damage kinase ataxia telangiectasia mutated (ATM) phosphorylates TAOs in vitro; radiation induces phosphorylation of TAO on a consensus site for phosphorylation by the ATM protein kinase in cells; and TAO and p38 activation is compromised in cells from a patient with ataxia telangiectasia that lack ATM. These findings indicate that TAO kinases are regulators of p38-mediated responses to DNA damage and are intermediates in the activation of p38 by ATM.
authors: Department of Pharmacology, University of Texas, Southwestern Medical Center, Dallas, TX 75390-9041, USA.
authors: Malavika
authors: M
authors: Raman
authors: Svetlana
authors: S
authors: Earnest
authors: Kai
authors: K
authors: Zhang
authors: Yingming
authors: Y
authors: Zhao
authors: Melanie H
authors: MH
authors: Cobb
mesh_terms: D064007:Ataxia Telangiectasia Mutated Proteins; D002453:Cell Cycle / Q000187:drug effects / Q000528:radiation effects; D018797:Cell Cycle Proteins / Q000378:metabolism; D045744:Cell Line, Tumor; D002851:Chromatography, High Pressure Liquid; D003001:Cloning, Molecular; D019295:Computational Biology; D004249:DNA Damage; D017931:DNA Primers; D004268:DNA-Binding Proteins / Q000378:metabolism; D004789:Enzyme Activation / Q000187:drug effects / Q000528:radiation effects; D005434:Flow Cytometry; D006801:Humans; D006918:Hydroxyurea / Q000494:pharmacology; D015151:Immunoblotting; D020930:MAP Kinase Kinase Kinases / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics; D053719:Tandem Mass Spectrometry; D025521:Tumor Suppressor Proteins / Q000378:metabolism; D014466:Ultraviolet Rays; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism*
chemical_list: D018797:Cell Cycle Proteins; D017931:DNA Primers; D004268:DNA-Binding Proteins; D034741:RNA, Small Interfering; D025521:Tumor Suppressor Proteins; C576324:ATM protein, human; D064007:Ataxia Telangiectasia Mutated Proteins; D017346:Protein Serine-Threonine Kinases; C115483:TAO1 protein kinase; D048051:p38 Mitogen-Activated Protein Kinases; D020930:MAP Kinase Kinase Kinases; D006918:Hydroxyurea