FIGURE 6.

Mutations that influence the conformation of the ECL2‐abrogated downstream signaling of GPR21. (A) Intra‐loop ionic lock stabilizing GPR21/52 ECL2 in G protein‐coupled receptors. Key residues are shown as sticks. (B) Mutations that influence the conformation of the ECL2‐abrogated cAMP accumulation. The cAMP response level in Δ169–187 (GS), Δ169–178 (GS), and Δ179–188 (GS) was compared with that of WT. **p < 0.01, t‐test, n = 3. (C) Flow cytometry analysis of surface expression level of WT GPR21, Δ169–187 (GS), Δ169–178 (GS), and Δ179–188 (GS)