Fig. 5: TM1^MOR suppresses both MOR and DOR homodimerization.

a Schematic figure showing the experimental design for examining the interaction (binding) of TM1^MOR with itself, MOR, and DOR. Colocalization indexes (b) and distributions of colocalization durations (c) showing that TM1^MOR forms metastable dimers with both MOR and DOR, while the control TM peptide (TM^LDLR) shows no interaction with either receptor, suggesting that TM1^MOR might be involved in MOR-MOR homodimerization as well as MOR-DOR heterodimerization⁴². d Schematic figure showing the experimental design for examining whether TM1^MOR can suppress homodimerizations of MOR and DOR. e TM1^MOR suppresses homodimerization of both MOR and DOR, but not KOR. In contrast, Mpep, Dpep, and Kpep selectively inhibit the homodimerization of MOR, DOR, and KOR, respectively. TM^LDLR hardly affects any OR homodimerization. In the box plots (b, e), horizontal bars, crosses, boxes, and whiskers indicate median values, mean values, interquartile ranges (25–75%), and 10-90% ranges, respectively. * and ns represent significant (p < 0.05) and non-significant (p ≥ 0.05) differences, respectively (Tukey’s multiple comparison test). All of the statistical parameters and analysis results including sample size n and p values are provided in Supplementary Data 2. Source data are provided as a Source Data file.