Figure 3.

Functional studies of trait-associated variants at the human PYY locus. Left panel, Transfected promoter studies. PYY promoter variants were ligated into the promoterless vector pGL3-basic, just upstream of the luciferase ORF. The transfected empty vector (pGL3-basic) yielded an expression value of about 0.7 × 10⁶ luciferase/β-galactosidase units. Right panel, Transfected 3′-UTR studies. PYY 3′-UTR variants were ligated into the XbaI site just downstream of the luciferase ORF in vector pGL3-promoter, in which expression is driven by the Simian virus 40 early promoter. In each case, plasmids were transfected into PC12 chromaffin cells, which were harvested for luciferase reporter activity at 24 h. The transfected empty vector (pGL3-promoter) showed an expression value of about 4.4 × 10⁵ luciferase/β-galactosidase units. Results were corrected for transfection efficiency by cotransfection of a β-galactosidase cDNA whose expression was driven by the cytomegalovirus promoter. Error bars, ±sem in four replicate transfections.