TRAPPC8 interacts mainly with TRAPPC2.

A. Increasing amounts of GFP-TRAPPC8 cDNA were co-transfected with a constant amount of Myc-TRAPPC2 and Myc-TRAPPC9. The levels of protein expression of all three TRAPP subunits were determined by immunoblotting the lysates of the transfected cells. B. Increasing amounts of GFP-TRAPPC9 cDNA were co-transfected with a constant amount of Myc-TRAPPC2 and Myc-TRAPPC8. C. GFP-tagged TRAPPC8 and the indicated Myc-tagged TRAPPI core subunits were co-transfected into COS cells. Co-IP and subsequent detection by immunoblotting was performed as in Figure 1. The experiments shown are representatives of three independent experiments.