Fig. 3.

A schematic representation of redox regulation of different kinds of transcriptional processes. A. An example of the redox regulation of the TF binding to the promoters of its target genes through an upstream regulator, Ref-1. A number of TFs have one or more reactive cysteines in their DNA binding domain, which are redox regulated by Ref-1 (APE-1) protein, which, in turn, is also redox regulated through its reactive cysteine. B. An example of the redox regulation of the TF binding to the promoters of its target genes under oxidative stress. The binding of Sp-1/Sp-3 to the promoters of its target genes is also redox regulated. Under basal condition, the binding of Sp-1/Sp-3 is very weak while oxidative stress induces their strong binding with the promoters of their target genes, which has been shown to be neuroprotective by our group. C. An example of indirect redox regulation of TFs by the change in redox states of co-factors such as NAD and NADH. The binding of CTBP-1, a co-repressor regulating the expression of BDNF with transcription factor NRSF depends upon NAD/NADH ratio. D. An example of the regulation of transcriptional processes through redox associated post-translation modifications. Redox regulation of HDAC2 through S-nitrosylation leads to its release, which, in turn, increases acetylation and enhances CREB dependent transcription.