title: Concentration-dependent effects of endogenous S-nitrosoglutathione on gene regulation by specificity proteins Sp3 and Sp1.
abstract: The activities of certain nuclear regulatory proteins are modified by high concentrations of S-nitrosothiols associated with nitrosative stress. In the present study, we have studied the effect of physiological (low microM) concentrations of the endogenous S-nitrosothiol, GSNO (S-nitrosoglutathione), on the activities of nuclear regulatory proteins Sp3 and Sp1 (specificity proteins 3 and 1). Low concentrations of GSNO increased Sp3 binding, as well as Sp3-dependent transcription of the cystic fibrosis transmembrane conductance regulatory gene, cftr. However, higher GSNO levels prevented Sp3 binding, augmented Sp1 binding and prevented both cftr transcription and CFTR (cystic fibrosis transmembrane conductance regulator) expression. We conclude that low concentrations of GSNO favour Sp3 binding to 'housekeeping' genes such as cftr, whereas nitrosative stress-associated GSNO concentrations shut off Sp3-dependent transcription, possibly to redirect cellular resources. Since low micromolar concentrations of GSNO also increase the maturation and activity of a clinically common CFTR mutant, whereas higher concentrations have the opposite effect, these observations may have implications for dosing of S-nitrosylating agents used in cystic fibrosis clinical trials.
authors.affiliation: Division of Pulmonary Medicine, Department of Pediatrics, University of Virginia School of Medicine, P.O. Box 800356, Charlottesville, VA 22908, USA.
authors.forename: Khalequz
authors.initials: K
authors.lastname: Zaman
authors.forename: Lisa A
authors.initials: LA
authors.lastname: Palmer
authors.forename: Allan
authors.initials: A
authors.lastname: Doctor
authors.forename: John F
authors.initials: JF
authors.lastname: Hunt
authors.forename: Benjamin
authors.initials: B
authors.lastname: Gaston
mesh_terms: D000818:Animals; D002460:Cell Line; D045744:Cell Line, Tumor / Q000187:drug effects; D016895:Culture Media, Serum-Free; D003513:Cycloheximide / Q000494:pharmacology; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000096:biosynthesis* / Q000235:genetics; D004268:DNA-Binding Proteins / Q000502:physiology*; D003609:Dactinomycin / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004331:Drosophila melanogaster / Q000166:cytology; D005786:Gene Expression Regulation / Q000187:drug effects*; D006801:Humans; D007555:Isoxazoles / Q000494:pharmacology; D008175:Lung Neoplasms / Q000473:pathology; D008926:Plicamycin / Q000494:pharmacology; D011485:Protein Binding / Q000187:drug effects; D011650:Pulmonary Alveoli / Q000473:pathology; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000502:physiology; D026422:S-Nitrosoglutathione / Q000008:administration & dosage / Q000494:pharmacology*; D015398:Signal Transduction / Q000502:physiology; D016329:Sp1 Transcription Factor / Q000235:genetics / Q000502:physiology*; D051705:Sp3 Transcription Factor; D014157:Transcription Factors / Q000502:physiology*; D014158:Transcription, Genetic; D014162:Transfection
chemical_list: C505032:CFTR protein, human; D016895:Culture Media, Serum-Free; D004268:DNA-Binding Proteins; D007555:Isoxazoles; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; C497121:SP3 protein, human; D016329:Sp1 Transcription Factor; D014157:Transcription Factors; D019005:Cystic Fibrosis Transmembrane Conductance Regulator; D051705:Sp3 Transcription Factor; D003609:Dactinomycin; D026422:S-Nitrosoglutathione; D003513:Cycloheximide; D008926:Plicamycin; C006303:acivicin