title: The redox-sensitive transcription factor Rap2.4a controls nuclear expression of 2-Cys peroxiredoxin A and other chloroplast antioxidant enzymes.
abstract: BACKGROUND
  The regulation of the chloroplast antioxidant capacity depends on nuclear gene expression. For the 2-Cys peroxiredoxin-A gene (2CPA) a cis-regulatory element was recently characterized, which responds to photosynthetic redox signals.
  
  
  RESULTS
  In a yeast-one-hybrid screen for cis-regulatory binding proteins, the transcription factor Rap2.4a was isolated. Rap2.4a controls the transcript abundance of the prominent chloroplast antioxidant enzyme through binding to the CGCG core of a CE3-like element. Rap2.4a activity is regulated by dithiol/disulfide transition of regulatory cysteinyl residues and subsequent changes in the quaternary structure. The mid-point redox potential of Rap2.4a activation is -269 mV (pH 7.0).
  
  
  CONCLUSIONS
  The redox sensitivity of Rap2.4a establishes an efficient switch mechanism for redox control of nuclear gene activity of chloroplast antioxidants, in which Rap2.4 is a redox-sensor and a transducer of redox information.
authors.affiliation: Plant Biochemistry and Physiology, Bielefeld University, 33501 Bielefeld, Germany. jehadgermany@gmx.de
authors.forename: Jehad
authors.initials: J
authors.lastname: Shaikhali
authors.forename: Isabelle
authors.initials: I
authors.lastname: Heiber
authors.forename: Thorsten
authors.initials: T
authors.lastname: Seidel
authors.forename: Elke
authors.initials: E
authors.lastname: Ströher
authors.forename: Heiko
authors.initials: H
authors.lastname: Hiltscher
authors.forename: Stefan
authors.initials: S
authors.lastname: Birkmann
authors.forename: Karl-Josef
authors.initials: KJ
authors.lastname: Dietz
authors.forename: Margarete
authors.initials: M
authors.lastname: Baier
mesh_terms: D000975:Antioxidants / Q000378:metabolism*; D017360:Arabidopsis / Q000166:cytology* / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D001665:Binding Sites; D002467:Cell Nucleus / Q000235:genetics / Q000378:metabolism*; D002736:Chloroplasts / Q000201:enzymology*; D004269:DNA, Bacterial / Q000378:metabolism; D004777:Environment; D017353:Gene Deletion; D018506:Gene Expression Regulation, Plant; D016254:Mutagenesis, Insertional; D010084:Oxidation-Reduction; D054464:Peroxiredoxins / Q000235:genetics / Q000378:metabolism*; D010641:Phenotype; D011401:Promoter Regions, Genetic / Q000235:genetics; D020836:Protein Structure, Quaternary; D021381:Protein Transport; D011523:Protoplasts / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D014158:Transcription, Genetic; D015533:Transcriptional Activation / Q000235:genetics
chemical_list: D000975:Antioxidants; D029681:Arabidopsis Proteins; D004269:DNA, Bacterial; D012333:RNA, Messenger; C036483:T-DNA; D014157:Transcription Factors; C493631:2-Cys peroxiredoxin A, Arabidopsis; D054464:Peroxiredoxins