title: Redox signaling regulates transcriptional activity of the Ca2+-dependent repressor DREAM.
abstract: DREAM/KChIP3 (Downstream Regulatory Element Antagonist Modulator) is a multifunctional Ca(2+)-binding protein that acts in the nucleus as a Ca(2+)-dependent transcriptional repressor. Binding to DNA and repressor activity of DREAM is regulated by Ca(2+), specific post-translational modifications as well as by protein-protein interactions with several nucleoproteins. Here, using the yeast two-hybrid assay, we characterized the interaction of DREAM with peroxiredoxin 3 (Prdx3), an antioxidant enzyme that uses the thioredoxin system as electron donor. Importantly, the DREAM/Prdx3 interaction is Ca(2+) dependent and is blocked by DTT. Coexpression of Prdx3 enhances DREAM binding to DRE sites and its repressor activity in vivo. Two cysteine residues in the N-terminal domain of DREAM are responsible for the redox modulation of its activity. Double Cys to Ser substitution results in a mutant DREAM with stronger repressor activity. Finally, we show that transient DREAM knockdown sensitizes PC12 cells to H(2)O(2)-induced oxidative stress, suggesting a protective role for DREAM against oxidative damage.
authors.affiliation: Dpto. Biología Molecular y Celular, Centro Nacional de Biotecnología, C.S.I.C., Madrid, Spain.
authors.forename: Marcos
authors.initials: M
authors.lastname: Rivas
authors.forename: Koldo
authors.initials: K
authors.lastname: Aurrekoetxea
authors.forename: Britt
authors.initials: B
authors.lastname: Mellström
authors.forename: José R
authors.initials: JR
authors.lastname: Naranjo
mesh_terms: D000818:Animals; D017209:Apoptosis; D016466:CHO Cells; D019556:COS Cells; D002470:Cell Survival; D002522:Chlorocebus aethiops; D006224:Cricetinae; D003412:Cricetulus; D003545:Cysteine / Q000378:metabolism; D005786:Gene Expression Regulation; D055785:Gene Knockdown Techniques; D051605:Kv Channel-Interacting Proteins / Q000235:genetics* / Q000378:metabolism; D009154:Mutation; D009474:Neurons / Q000166:cytology / Q000378:metabolism; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D016716:PC12 Cells; D054464:Peroxiredoxins / Q000378:metabolism*; D011485:Protein Binding; D051381:Rats; D017382:Reactive Oxygen Species / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism; D050436:Regulatory Elements, Transcriptional; D015398:Signal Transduction; D020798:Two-Hybrid System Techniques
chemical_list: D051605:Kv Channel-Interacting Proteins; D017382:Reactive Oxygen Species; D011994:Recombinant Proteins; D054464:Peroxiredoxins; D003545:Cysteine