FIGURE 5.

Gbf1(L1246R) mutant protein is unable to be recruited to the Golgi apparatus in HeLa cells. A–F, location of expressed Flag-Gbf1 (A, C, and E) and mutant Flag-Gbf1(L1246R) proteins (B, D, and F) in the absence (A and B) or presence (C–F) of BFA (C and D) for 10 min or GCA (E and F) for 30 min. The insets are enlarged boxed areas showing co-localization of exogenous Gbf1 with the cis-Golgi marker GM130. Note that BFA or GCA treatment enriched WT Gbf1 in the Golgi region (C and E) but had little effect on mutant Gbf1 (D and F). More dispersed and weaker GM130 signals in BFA- or GCA-treated cells (C–F) may be caused by partial disruption of the Golgi apparatus because of inhibition of endogenous Gbf1. G, statistical results of relative Gbf1 signal in the Golgi region. Fold of enrichment at Golgi was expressed as the ratio of the Flag-Gbf1 signal co-localized with the GM130-labeled Golgi region to the Flag-Gbf1 signal in the whole cell. Nc, observed number of cells; ns, statistically nonsignificant; ***, p < 0.001.