Figure 5.

The LL motif mediates the surface transport from the ER of wild-type and chimeric GPCRs in HEK293 and SHSY5Y cells

(A) The surface expression of M3R and its LL-AA mutant. The cells were transfected with M3R or its mutant and their surface expression was measured by radioligand binding of intact live cells. The data are expressed as percentages of WT. Bars represent mean ± SE (n = 3). Unpaired Student's t test; ∗p < 0.001 versus WT.

(B) Subcellular distribution of M3R and its LL-AA mutant. M3R or its LL-AA mutant was transfected together with the ER marker DsRed-ER and their colocalization was revealed by confocal microscopy. The images shown are representatives of 3 experiments. Scale bar, 10 μm.

(C) A diagram showing the generation of the chimeric receptor β₂ARα_2Bct in which the β₂-AR CT was substituted with the α_2B-AR CT containing the IL motif.

(D) Subcellular distribution of β₂ARα_2Bct and its IL-AA mutant. β₂ARα_2Bct or its IL-AA mutant was transfected together with the ER marker DsRed-ER. The images shown are representatives of 3 experiments. Scale bar, 10 μm.