Fig. 5.

ECE-1 regulation of postendocytic sorting of NK₁R and β-arrestin-1 in HEK cells. Cells were incubated with SP, washed, recovered for 0–6 h. (A) In HEK-HA11NK₁R cells (surface NK₁R labeled with anti-HA11), SP caused NK₁R endocytosis and recycling at 6 h. SM-19712 caused NK₁R retention in endosomes and inhibited recycling at 6 h. (B) In HEK-HA11NK₁R cells expressing β-arrestin-1-YFP, SP caused sequestration of β-arrestin-1-YFP in endosomes and redistribution to the cytosol at 3 h. SM-19712 prevented the return of β-arrestin-1-GFP to the cytosol and caused its retention in endosomes at 3 h. (Scale bars, 10 μm.)