Fig. 2.

The −7-kb POMC conserved region has enhancer properties. A, Activities of luciferase reporter constructs containing either 6.9- or 7.7-kb upstream 5′ flanking sequences upon transfection in AtT-20 cells. B, Activity (relative to minimal promoter construct) of various luciferase reporters upon transfection of AtT-20 cells. The light gray box represents the −480/−34-bp proximal promoter while the darker gray box represents the enhancer located at −7 kb in the POMC locus. C, Hormone response of POMC luciferase reporters containing either minimal (−34/+63-bp) promoter, −7-kb enhancer, −480-bp proximal promoter or −7.7-kb 5′ flanking sequences. Activation is relative to nontreated cells (Ctl). All data represent the means (± sem) of independent experiments [n = 3 (A), 7 (B), and 4 (C)] each performed in duplicates.