Figure 1.

Effects of PI4KIIα RNAi on the intracellular distribution of the GGAs and Arf in cells. (A–C) Effects on GGA localization. Endogenous GGA1, 2, and 3 were detected with isoform-specific antibodies. The TGN was stained with anti-TGN46. Western blot in A shows the partitioning of GGA1, PI4KIIα, and βCOP in the 100,000 × g supernatants (S) and pellets (P). Densitometry scanning showed that there was a 40 ± 7% (n = 3) decrease in membrane-associated GGA1 in the PI4KIIα-RNAi–treated cells. (D) Effects on Arf localization. The anti-Arf antibody recognizes all Arfs, but Arf1 is the most abundant and it is concentrated in the Golgi apparatus. Scale bar, 20 μm.