Identification of 3',5'-cyclic adenosine monophosphate-inducible nuclear factors binding to the human urokinase promoter in mouse Sertoli cells.

Transcription factors which recognize both the SV40 promoter and the proximal promoter region of the human urokinase-type plasminogen activator (h-uPA) gene are present in nuclear extracts from primary cultures of mouse Sertoli cells; prolonged (more than 12 h) (Bu)2cAMP stimulation of Sertoli cells induces the formation of different specific DNA-protein complexes. A discrete region in the h-uPA promoter, between -54 and -42, is essential for the formation of the cAMP-induced DNA-protein complexes. Mutation of the sequence between -54 and -42 abolishes the response to cAMP of the proximal h-uPA promoter in Sertoli cells. A protein, recognizing a sequence centered around the GC-box present between -48 and -43, is detected by Southwestern analysis, and it is clearly induced by (Bu)2cAMP stimulation. Interaction between this protein and a second factor, recognizing a purine-rich sequence between -53 and -46, partially overlapping the GC-box, is needed for the formation of the cAMP-induced DNA-protein complexes. A preformed complex between the cAMP-induced GC-box-binding factor and the second factor can be detected using nondenaturing conditions during Southwestern analysis.