In vitro transport assays reveal retrograde trafficking of select Golgi enzymes from the cell surface to the trans-Golgi network, indicating an active enzyme retrieval pathway.
Key Points
To determine whether Golgi-resident enzymes that reach distal sites such as the plasma membrane can be recaptured and returned to the trans-Golgi network.
Tracked enzyme localization and transport using fluorescent and sulfation-competent nanobody-based assays.
Compared retrograde trafficking of Golgi-resident enzymes to standard internalization pathways of classical recycling receptors.
Select Golgi enzymes at the plasma membrane underwent retrograde transport back to the trans-Golgi network and sulfation compartment.
Abundant classical recycling receptors efficiently internalized nanobodies but did not traffic retrogradely to the trans-Golgi network.