Ataxia telangiectasia-mutated, a DNA damage-inducible kinase, contributes to high NaCl-induced nuclear localization of transcription factor TonEBP/OREBP.
High NaCl activates the transcription factor tonicity-responsive enhancer/osmotic response element binding protein (TonEBP/OREBP) by increasing its abundance and transactivation, the latter signaled by a variety of protein kinases. In addition, high NaCl causes TonEBP/OREBP to translocate into the nucleus, but little is known about the signals directing this translocation. The result is increased transcription of protective genes, including those involved in accumulation of organic osmolytes. High NaCl also damages DNA, and DNA damage activates ataxia telangiectasia-mutated (ATM) kinase through autophosphorylation on serine 1981. We previously found that ATM is involved in the high NaCl-induced increase in TonEBP/OREBP transactivation. The purpose of the present studies was to test whether ATM is also involved in high NaCl-induced TonEBP/OREBP nuclear translocation. We quantified TonEBP/OREBP in nuclear and cytoplasmic extracts from cultured cells by Western blot analysis. In COS-7 cells, wortmannin, an inhibitor of ATM, reduces high NaCl-induced nuclear translocation of TonEBP/OREBP. We used AT cells (in which ATM is inactive) to test the specificity of this effect. Nuclear translocation of native TonEBP/OREBP and of its recombinant NH2-terminal rel homology domain, which contains the nuclear localization signal, is reduced in AT cells and is restored when the cells are reconstituted with functional ATM. In conclusion, activation of ATM contributes to high NaCl-induced nuclear translocation of TonEBP/OREBP.
Zhang
Zheng
Z
Laboratory of Kidney and Electrolyte Metabolism, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland, USA. zzhang3@vcu.edu
Ferraris
Joan D
JD
Irarrazabal
Carlos E
CE
Dmitrieva
Natalia I
NI
Park
Jong-Hwan
JH
Burg
Maurice B
MB
D000730:Androstadienes / Q000494:pharmacology; D000818:Animals; D064007:Ataxia Telangiectasia Mutated Proteins; D019556:COS Cells; D006528:Carcinoma, Hepatocellular; D018797:Cell Cycle Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism*; D045744:Cell Line, Tumor; D002467:Cell Nucleus / Q000378:metabolism; D002522:Chlorocebus aethiops; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D004249:DNA Damage / Q000502:physiology*; D004268:DNA-Binding Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D007976:Leupeptins / Q000494:pharmacology; D008113:Liver Neoplasms; D050778:NFATC Transcription Factors; D009997:Osmotic Pressure; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D012965:Sodium Chloride / Q000494:pharmacology; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014162:Transfection; D025521:Tumor Suppressor Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism*; D014882:Water-Electrolyte Balance / Q000502:physiology*; D000077191:Wortmannin
D000730:Androstadienes; D018797:Cell Cycle Proteins; D015853:Cysteine Proteinase Inhibitors; D004268:DNA-Binding Proteins; D007976:Leupeptins; C118125:NFAT5 protein, human; D050778:NFATC Transcription Factors; D047428:Protein Kinase Inhibitors; D011994:Recombinant Proteins; D014157:Transcription Factors; D025521:Tumor Suppressor Proteins; D012965:Sodium Chloride; C576324:ATM protein, human; D064007:Ataxia Telangiectasia Mutated Proteins; D017346:Protein Serine-Threonine Kinases; C072553:benzyloxycarbonylleucyl-leucyl-leucine aldehyde; D000077191:Wortmannin