Fig. 6. The extreme C-terminal end of sG_i2 is essential for the intracellular interaction. (A) For deletion experiments, sG_i2 constructs were prepared by eliminating the part of the complete cDNA sequence with the use of specific PCR primers and then cloned. Each bar reflects the approximate size and location of each construct included in the study. Numbers on the right indicate start and end of the cDNA sequence. sG_i2 (WT) and G_i2 (WT) are complete genes and rest (c-f) are the constructs derived from sG_i2 (WT). Shaded areas show the sequences that differ between sG_i2 and G_i2. G_i2 was included in the study as control. (B) Each of the constructs or WT (a-f) from (A) was co-expressed with D_2S receptor in BHK cells and the receptor density at cell surface was assayed in intact cells. The protein expression of these constructs was confirmed by western blots (see supplementary material Fig. S5).The 108 base pairs on the extreme 3'-end were necessary for the intracellular interaction and retention of the receptor. Values are representative of five different experiments.