Oxidation of nuclear thioredoxin during oxidative stress

Thioredoxin 1 (Trx1) is a key redox control system within the nucleus, yet little is known about the sensitivity of nuclear Trx1 to oxidative stress. The present study compared oxidant-induced changes in the redox states of nuclear Trx1, cytoplasmic Trx1, and cellular glutathione (GSH). Nuclear Trx1 was more reducing than cytoplasmic Trx1 and cellular GSH in proliferating cells. tert-Butylhydroperoxide caused an increase in the total amount of nuclear Trx1, but this was accompanied by a 60 mV oxidation. Thus, the increase in nuclear Trx1 levels did not correspond to an increase in the overall reducing capacity of Trx1 in the nucleus. (C) 2003 Federation of European Biochemical Societies. Published by Elsevier Science B.V. All rights reserved.