Fig 7. Schematic of the proposed role of arfaptin-1 in Arl1-mediated retrograde transport.

Arfaptin-1 is recruited to the TGN through interaction with GTP-bound Arl1, where it inhibits vesicle transport from endosomes to the Golgi. Arfaptin-1 disassociates from GTP-bound Arl1 until protein kinase D phosphorylates arfaptin-1 at the N-terminus. The GTP-bound Arl1 then recruits GRIP domain-containing proteins to the TGN and receives the cargo proteins transported from the endosomes to the Golgi.