Fig. 3.

Identification of domain of SP1 responsible for interaction with ERα or C/EBPβ. (A) A schematic presentation of V5 epitope-tagged deletion forms (mS1 to mS5) of human SP1. GST-ERα (B) or GST-C/EBPβ (C), purified by GST affinity resin, was incubated with various in vitro-translated deletion forms of SP1 in the presence or absence of 17β-estradiol (E2; 100 nM). The inputs and interacting forms of SP1-V5 were detected by Western blot analysis using V5 antibody. Results are representative of three independent experiments.