Immunoblot Detection of the Phosphorylation of the Estrogen Receptor α as an Outcome of GPR30 /GPER1 Activation.

Phosphorylation of the serine residues in estrogen receptor (ER) α is important in transcriptional activation. Hence, methods to detect such posttranslational modification events are valuable. We describe, in detail, the analysis of the phosphorylated ERα by electrophoretic separation of proteins and subsequent immunoblotting techniques. In particular, phosphorylation of the ERα is one possible outcome of activation of the putative membrane estrogen receptor (mER), GPR30 or GPER1. Hence, phosphorylation represents a crosstalk event between GPR30 and ERα and may be important in estrogen-regulated physiology.