DNase I footprint analysis of the GPV promoter fragment IV using HeLa, Dami, and Raji cell extracts. The 5′-end-labeled fragment IV (nt −935 to −441) was analyzed as described in the legend to Fig 4, using HeLa, Dami, and Raji nuclear extracts. “R_IIb” is a putative repressor binding site with homology to a repressor site in the GPIIb promoter,31whereas “ETF” is a putative binding site for ETF, a member of the Sp1 family.65