Electrophoretic Mobility Shift Assay (EMSA) and Supershift Assay of Cytochrome P450 2B6 in Response to Estrogen

Electrophoretic mobility shift assay (EMSA) is an invaluable tool to study interaction of proteins with DNA. Estrogens are major female hormones and modulate biological function through estrogen receptor (ER). ER regulates its target gene expression via the classical mechanism in which ER directly binds to its target gene promoter or the nonclassical mechanism involving tethering of ER to other transcription factors (such as AP-1 proteins). Here, we describe the EMSA to examine the nonclassical mechanism of ER action in regulation of a gene CYP2B6 by using competition and supershift assays.