Fig. 2.
Detection of DNase I hypersensitive sites in the regulatory region of the uPA gene.
(A) Schematic representation of the region analyzed by DNase I hypersensitivity. The location of the enhancer (■), proximal promoter (▪), and probe (p2, ░) used are indicated; the location of the restriction sites (Xmn I) is also indicated. Purified, DNase I–digested and restricted DNA was fractionated on a 1% agarose gel in 0.5 × TBE, transferred to positively charged nylon membrane, and probed as described.29 (B) In PC3 cells the regulatory region of the uPA gene displays strong hypersensitivity to DNase I in proximity of the enhancer (∼−1950) and the proximal promoter (∼−86). The latter is completely absent in HeLa cells. The asterisks indicate nonspecific bands also present in lanes 1 and 6, where no DNase I was used.