HORMONE-REGULATABLE NEOPLASTIC TRANSFORMATION-INDUCED BY A JUN-ESTROGEN RECEPTOR CHIMERA

The v-jun oncogene encodes a nuclear DNA binding protein that function s as a transcription factor and is part of the activator protein 1 com plex, Oncogenic transformation by v-jun is thought to be mediated by t he aberrant expression of specific target genes. To identify such Jun- regulated genes and to explore the mechanisms by which Jun affects the ir expression, we have fused the full-length v-Jun and an amino-termin ally truncated form of v-Jun to the hormone-binding domain of the huma n estrogen receptor, The two chimeric proteins function as ligand-indu cible transactivators, Expression of the fusion proteins in chicken em bryo fibroblasts causes estrogen-dependent transformation.