GLUTAREDOXIN IS A DIRECT TARGET OF ONCOGENIC JUN

We have analysed differential gene expression in v-jun-transformed chi cken embryo fibroblasts (CEF) compared to normal CEF by using the dire ctional tag PCR subtraction method. From a first generation of putativ e Jun targets four clones were selected for study; they are upregulate d in jun-transformed cells. Three of these clones showed homology to k nown genes: glutaredoxin, growth associated protein (GAP)-43/neuromodu lin, and phenobarbital-induced cytochrome P450. The expression of thes e genes was analysed in fibroblasts transformed by various oncogenes. Expression of the glutaredoxin mRNA could be induced by a Jun-estrogen receptor chimaera in the absence of de novo protein biosynthesis. Bas ed on this observation we conclude that glutaredoxin is a direct targe t of v-Jun.