Figure 5. WT 5-HT₃A and mutant 5-HT₃A(C312A) subunits enable surface localization of the 5-HT₃B subunit.

Total and surface labelling of HEK293 cells transiently expressing HA-5-HT₃B alone (A) or in combination with either Myc-5-HT₃A (B) or Myc-5-HT₃A(C312A) (C). Labelling was performed as described for Fig. 4. The distribution of receptor subunits was examined by confocal microscopy. Representative images from two independent experiments performed in duplicate are shown. Scale bar is 16 μm. D, surface expression level of 5-HT₃B with co-expression of WT 5-HT₃A or mutant 5-HT₃A(C312A) quantified using ELISA. Expression level of 5-HT₃B with co-expression of 5-HT₃A was normalized as 100%. Data are presented as means ±s.e.m. of 3–5 independent experiments performed in triplicate. *P < 0.05 (t test).