AP-1 DNA-BINDING ACTIVITY IS INHIBITED BY SELENITE AND SELENODIGLUTATHIONE

The binding of the transcription factor AP-1 to DNA has been shown to be modulated by redox control mechanisms, Selenite and selenodiglutath ione (GS-Se-SG), inhibit mammalian cell growth and are efficient oxida nts of reduced thioredoxin and reduced thioredoxin reductase, Here, we report that selenite and GS-Se-SG efficiently inhibited AP-1 DNA-bind ing in nuclear extracts from 3B6 lymphocytes, A GS-Se-SG concentration of 0.75 mu M resulted in 50% inhibition of AP-1 DNA-binding, whereas the same effect was achieved with 7.5 mu M selenite, Nuclear extracts prepared from human 3B6 lymphocytes exposed for 4 h to 10 mu M selenit e showed a 50% reduction of AP-1 binding, These data suggest that sele nite and selenodiglutathione inactivate the AP-1 factor and provide a mechanism by which selenium compounds inhibit cell growth.