The gonadotropin alpha-gene contains multiple protein binding domains that interact to modulate basal and cAMP-responsive transcription.

摘要: DNA sequences that modulate basal and cAMP-stimulated transcription are located within the initial 169 base pairs of alpha-gene 5'-flanking sequence. Using DNase I protection analyses gel-mobility shift assays, we examined in vitro domains human sequence bind nuclear proteins extracted from JEG-3 choriocarcinoma cells. studies between -236 -100 demonstrate two major protected regions: -178 to -156 corresponding an upstream regulatory element (URE) -146 -112 18-base pair repeated contain cAMP-responsive enhancers (CREs). Nuclear cells specifically oligonucleotides both URE CRE as well a downstream domain (-99 -72) contains consensus CCAAT motifs on sense antisense strands. Binding fragment (-236 -100) was 10-fold more effective than using either alone. this multisite is readily disrupted sequence, but not competitor, suggesting binding factor may stabilize DNA-protein interactions these adjacent complexes. The amount protein each unaffected by treatment with 8-bromo-cAMP. These indicate there multiple correspond cis-acting elements including activates expression, cAMP-response elements, containing box elements. Interactions facilitate synergistically stimulate transcription.