Figure 8.

Expression of ARF1 or GBF1 rescues β-COP disassembly induced by the N121I mutant. HeLa cells were cotransfected with GFP-tagged N121I mutant and HA-tagged wild-type ARF1 (A) or with GFP-tagged N121I mutant and myc-tagged GBF1 (B). After 24 h, cells were analyzed by immunofluorescence with anti-β-COP antibodies and with either anti-HA or anti-myc antibodies. GFP-N121I was detected by green fluorescence. In cotransfected cells (arrowheads), β-COP is membrane associated. In cells transfected only with N121I (asterisks), β-COP is cytosolic. In C, cells were transfected only with myc-tagged GBF1. Overexpression of GBF1 causes partial Golgi fragmentation. Bars, 10 μm.