Testosterone regulates tissue-specific changes in the binding of a 47-kilodalton protein to a highly conserved sequence in the 3' untranslated region of epidermal growth factor messenger ribonucleic acid.

Epidermal growth factor (EGF) transcripts that use the terminal polyadenylation signal display a dramatic sex difference in the pattern of polyadenylation in the murine submaxillary gland (SMG), whereas those in the kidney do not. It takes 3 days before testosterone treatment begins to change the polyadenylation pattern in female SMG to resemble the male pattern, a finding that supports previous suggestions that posttranscriptional mechanisms are involved in regulating EGF expression. The conservation of a unique 23-b sequence centered on the terminal polyadenylation signal in all published mammalian EGF sequences suggested that trans-acting factors involved in EGF messenger RNA (mRNA) metabolism might bind to this sequence. To investigate this, we prepared 32P-RNA containing the 3' terminal EGF 23-b sequence plus a short poly-A tail, and incubated it with SMG cytosol. Cytosol retarded the electrophoretic mobility of this RNA as a single prominent band on 8% PAGE, and by UV-cross-linking, a single promine...