Figure 9.

Non-constitutively active GRID2 agonist binding domain variants alter d-serine and Ca²⁺ potency. For each experiment, same day control curves recorded for the lurcher variant GluD2-A654T are shown. (A) Ca²⁺ concentration-response curve for inhibition of GluD2-A654T-R710W and -A654T (B) Ca²⁺ concentration-response curve for inhibition of GluD2-A654T, D535E and GluD2-A654T. Unlike GluD2-A654T, GluD2-A654T,D535E is weakly inhibited by Ca²⁺. (C) d-Serine concentration-response of GluD2-A654T, R710W and GluD2-A654T. (D) d-Serine concentration-response of GluD2-A654T,D535E and GluD2-A654T. (E) GluD2 protein structure (GluD2 homology model) with a closer view of the GluD2 agonist binding domain shows the location of GluD2-R710W and GluD2-D535E. (F) Variant GluD2-D535E is at a site that is important for Ca²⁺ binding (PBD: 2V3T).