Initial screen of GPER’s submembrane domains for CaM binding.

<p>Incremental purified CaM was titrated as the entire emission spectra of BSGPER_83–93 (SMD1, <i>A</i>) BSGPER_150–175 (SMD2, <i>B</i>), BSGPER_242–259 (SMD3, <i>C</i>) and BSGPER_330–375 (SMD4, <i>D</i>) were monitored. Initial reaction mix contained 500 nM BSGPER_x, 0.1 mg/mL BSA, and 3 mM Ca²⁺. Clear responses were observed for all SMDs.