Fig. 6: Effects of M-agonists, morphine and DAMGO, on DM heterodimerization, and of Dpep(20-42)DM on DM heterodimerization, in the presence of M-agonists.
a Experimental PCCFs for DM heterodimerization in the presence and absence of 0.5 µM M-agonists and 1 µM Dpep(20-42)DM (mean ± SEM; n = 20 replicates) and their fitting curves using KD for DM heterodimerization and σ (precisions of single-molecule localizations for the two probes and spatial precision for overlaying two-color images) as fitting parameters. MD-cells expressing both DOR and MOR at 0.5-1.0 fluorescent spots/µm2 were employed. b Colocalization indexes obtained from the PCCFs shown in a. Together with the results shown in a, the results indicate that morphine hardly affects DM heterodimerization whereas DMAGO enhances it. The Dpep(20-42)DM addition significantly reduces DM heterodimers under all conditions examined here. In the box plots, horizontal bars, boxes, and whiskers indicate 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. c Morphine shortens and DAMGO prolongs DM heterodimer lifetimes, whereas the further addition of Dpep(20-42)DM reduces the lifetimes, making them shorter than those for DM heterodimers without any treatment. d Schematic summary of KD and koff values for DM heterodimers in the presence and absence of DAMGO and DpepDM(20-42)DM. Source data are provided as a Source Data file.
