COOPERATIVE INTERACTION BETWEEN ETS AND AP-1 TRANSCRIPTION FACTORS REGULATES INDUCTION OF GLUTATHIONE-S-TRANSFERASE YA GENE-EXPRESSION

Induction of mouse glutathione S-transferase (GST) Ya gene expression by a variety of chemical agents is mediated by a regulatory element, E pRE, composed of an Ets and two adjacent AP-1-like binding sites. In t his report we present evidence that the basal and inducible activity o f EpRE is mediated by AP-1 transcription factor and that the cooperati ve interaction between AP-1 and an Ets protein contributes to enhance the EpRE inducibility. We also show that EpRE, similar to a single AP- 1 site, when ligated to GST Ya gene promoter, is transactivated by c-F os/c-Jun or c-Fos/Jun-B heterodimer and that c-Jun/c-Jun homodimer is an activator of an AP-1 site only in the context of collagenase gene p romoter. (C) Academic Press, Inc.