Fig. 2.

(A) Schematic representation of chimeric receptor V1a/VRR1. The chimera consists of the N terminus, extracellular loops, and transmembrane domains of the V1a receptor (open) and the intracellular loops and C terminus of the VRR1 receptor (filled). (B) Saturation binding of [³H]AVP (0 to 10 nM) to V1a/VRR1 (squares) and to control HEK293 membranes (triangles). V1a/VRR1 bound to AVP with a dissociation constant (K_d) of 0.56 ± 0.1 nM. (C) Scatchard plot. B_max was ≈3.8 pmol/mg membrane protein, corresponding to 0.38 nM.