Figure 1.

Construction of the NT₁-GFP viral vector. A, Strategy for subcloning the NT₁ receptor gene and IRES sequence into the pCMO2 backbone to produce the NT₁-GFP vector. B, HEK 293 cells infected with the NT₁-GFP vector increased NT₁ receptor binding and expression of GFP, whereas cells infected with the GFP vector did not express the receptor but expressed GFP fivefold greater than cells infected with the NT₁-GFP vector. Results are mean ± SEM of triplicate experiments. ^*p < 0.001 compared with cells infected with the GFP vector (Student's t test). C, Demonstration of coupling of the virally overexpressed NT₁ receptor to cAMP and IP₃ formation in HEK 293 cells. Data are mean ± SEM. ^*p < 0.05, ^**p < 0.01, and ^***p < 0.001 compared with cells infected with the GFP virus within the same treatment group; ⁺p < 0.001 compared with other NT₁-GFP groups that received NT but not SR 142948A. The vehicle for SR 142948A was DMSO (final concentration, 0.1%) in saline. prot, Protein.