Ciliary membrane proteins traffic through the Golgi via a Rabep1/GGA1/Arl3-dependent mechanism

Polycystins (PC) 1 and 2 are large transmembrane proteins that play a vital role in the function of primary cilia. Here, Kim et al. identify the requirements for polycystin trafficking to the cilium, involving a PC1–PC2 interaction, PC1 proteolytic cleavage and a specific trafficking module at the trans-Golgi network.