Dynamics of SSTR2 trafficking. (A) HeLa cells transfected with EGFP-SSTR2 were imaged for 5 min in the absence of stimulation (top two panels), for 42 min 6 min after applying [D-Trp⁸]-SOM (middle two panels), or for 22 min 8 min after agonist washout (bottom two panels). The images are the first and last frames from Videos 1, 2, and 3, respectively. (B) HeLa cells were transfected with EGFP-SSTR2 and Ds-Red-syntaxin-6. Cells were incubated for 60 min with 100 nM of [D-Trp⁸]-SOM followed by brief acid wash, and the cells were then imaged using a Zeiss LSM 880 microscope with airyscan at 10- to 20-s intervals. The images represent frames from Videos 4 and 5. The boxed areas in the top panel are shown at higher magnification below. The dashed lines in B indicate SSTR2/syntaxin-6–positive vesicles. Scale bars in A and B represent 5 µm and 1 µm for the low- and high-magnification images, respectively. (C) HeLa cells were transfected with EGFP-SSTR2 and imaged live following 60 min of [D-Trp⁸]-SOM incubation and a brief acid wash. Representative cropped frames from Video 6 are shown. The arrows indicate SSTR2 transport on a tubular carrier. Scale bar represents 5 µm.