An enhancer "core" DNA-binding and transcriptional activity is induced upon transformation of rat embryo fibroblasts.

A novel DNA-binding activity, hereafter referred to as MECA, is induced upon transformation of rat embryo fibroblasts by the collaborative action of the oncogenes myc and ras. MECA is targeted to the enhancer "core" element of the Moloney Murine Leukemia Virus LTR. Its binding site can direct transcription from a heterologous promoter and EJras, but not c-myc, potentiates the transcriptional activity. A two point mutation within the enhancer "core" abolishes both DNA-binding by MECA and transcriptional activity. MECA may mediate some of the transforming effects of ras, and thus belongs in the family of transformation-specific DNA-binding activities with members such as AP-1, PEA3 and NF-kB.