Figure 3.

Comparison of SBP-GFP-tagged CDMPR, NAGPA, and LAMP1. (A) Like SBP-GFP-CDMPR, both SBP-GFP-NAGPA and SBP-GFP-LAMP1 are retained in the ER in the absence of biotin, and there is no detectable uptake of nanobody. After 90 min in biotin, both have reached their normal steady state localization and have endocytosed substantial amounts of nanobody, which was added for the final 30 min. Scale bar: 10 μm. (B) Cells expressing SBP-GFP-CDMPR, SBP-GFP-NAGPA, or SBP-GFP-LAMP1 were transfected with HaloTag-gadkin and then treated with biotin for 90 min. Both SBP-GFP-CDMPR and SBP-GFP-NAGPA show strong colocalization with gadkin at the cell periphery, while SBP-GFP-LAMP1 does not. This colocalization with gadkin is indicative of an association with AP-1. Scale bar: 10 μm.