Modulation of transcription factor NF-kappa B binding activity by oxidation-reduction in vitro.

Abstract

NF-icB is a widely used regulator of inducible and tissue-specific gene control. In the cytosol, when complexed to an inhibitory molecule, IKB, NF-#cB is in an inactive form and cannot bind DNA. Activation of cells with appropriate stimuli results in the dissociation of NF-mcB from IjcB and its translocation to the nucleus as an active binding protein. We now demonstrate that NF-ucB binding in vitro can be inhibited by agents that modify free sulfhydryls. Binding is eliminated after treatment with N-ethylmaleimide, an alkylating agent, and diamide, an oxidizing agent. The diamide effect can be reversed by 2-mercaptoethanol. Further, 2-mercaptoethanol acts synergistically with deoxycholate plus Nonidet P-40 in converting inactive cytosolic NF-KB to an active DNA-binding form. It is therefore possible that modulation of the redox state of NF-KB could represent a post-translational control mechanism for this factor.

A redox cycle within the cell cycle: ring in the old with the new

“…The promoter region of cyclin D1 gene contains binding sites for redox-sensitive transcription factors including cyclic adenosine monophosphate response element-binding protein, nuclear factor-kB (NF-kB), activator protein 1 and Sp1. Several reports show redox modifications of critical cysteines in these transcription factors regulate their DNA-binding activities (Abate et al, 1990;Toledano and Leonard, 1991;Manome et al, 1993;Ohba et al, 1994;Janssen et al, 1995;Lo and Cruz, 1995). Hence, redox-state-dependent modulation of the activity of these transcription factors could significantly influence cyclin D1 transcription.…”

Redox signalling by transcription factors NF-κB and AP-1 in lymphocytes

“…Unlike the bacterial peroxide sensor OxyR that can be activated by oxidation in vitro, oxidation of purified NF-KB-IKB does not activate but even causes a loss of DNA-binding activity [38]. A conserved cysteine residue in the DNA-binding domain of NF-KB subunits seems to be responsible for this oxidative inhibition [39].…”

Continuous overexpression of thioredoxin 1 enhances cancer development and does not extend maximum lifespan in male C57BL/6 mice

“…Both Trx1 and 2 play essential biological roles in mammals. Some of the physiologically important roles of Trx include: 1) acting as a hydrogen donor for enzymes involved in reductive reactions [3–8]; 2) maintaining a reduced environment in cells [9]; 3) controlling protein (especially transcription factors) function via the redox state [10–12] and the expression of target genes; 4) protecting cells and tissues from oxidative stress [13]; and 5) having anti-apoptotic effects through the inhibition of the ASK [14] and mitochondrial pathways [15]. The essential biological roles of Trx were further supported by two studies which demonstrated that mice null for either Trx1 or Trx2 were embryonically lethal [16,17].…”