AP-1, SP-1, and Egr-1 binding in nuclear extracts from HA-1 cells incubated with 100 μM ZnCl₂ or 10 μM MPs for 24 hours.

Each panel represents an electrophoretic mobility shift gel from 3 separate experiments. (A) AP-1 binding. Lane F, free probe; lane C; untreated control; lane ZC, cells incubated with ZnCl₂; lane ZP, cells incubated with ZnPP; lane SP, cells incubated with SnPP; lane CP, cells incubated with CrPP; lane ZC+AP-1, ZnCl₂treated cells incubated with a 100-fold excess of cold AP-1 probe to demonstrate specificity of binding. (B) SP-1 binding. Lane F, free probe; lane C, untreated control; lane ZC, cells incubated with ZnCl₂; lane ZP, cells incubated with ZnPP; lane CP, cells incubated with CrPP; lane SP, cells incubated with SnPP; lane ZC+SP-1, ZnCl₂ treated cells incubated with a 100-fold excess of cold SP-1 probe to demonstrate specificity of binding. (C) Egr-1 binding. Lane F, free probe; lane C, untreated control; lane ZP, cells incubated with ZnPP; lane ZC, cells incubated with ZnCl₂; lane CP, cells incubated with CrPP; lane SP, cells incubated with SnPP; lane ZP+Egr-1, ZnPP-treated cells incubated with a 100-fold excess of cold Egr-1 probe to demonstrate specificity of binding. In each gel, cold competition was performed with the compound leading to the highest nuclear protein binding.