Thioredoxin and Redox Regulation of the Nuclear Receptor

Oxidative stress evokes various cellular responses including alteration of gene expression to preserve cellular homeostasis (1 ,2 ). Thioredoxin (TRX) is a small ubiquitous protein with protein thiol-reducing activity and has been shown to function as a cellular antioxidant buffering system in response to oxidative stress and play essential roles in maintenance of cellular function (3 ,4 ). Recently, a growing number of evidence has shown that TRX plays crucial roles in redox regulation of gene expression via either direct or indirect interaction with various transcription factors including NF-κB (5 ), AP-1 (6 ), and PEBP2 (7 ). Alteration in expression and/or subcellular localization of TRX has been indicated to be involved in such redox-dependent control of the transcription factors (8 ,9 ), however, precise mechanisms remain unknown.