Suppression of intercisternal transport of the fluorescent secretory cargo. (A) Fluorescent secretory cargo levels during the early-to-late Golgi transition after eliminating AP-1 or asparagine-linked glycosylation. The analysis was performed as in Fig. 6 C, except that Z-stacks were captured every 2 s. For each yeast strain, 17 early-to-late Golgi transitions visualized in at least nine videos were averaged. Where indicated, the cells lacked AP-1 due to an apl4Δ mutation, or the secretory cargo lacked asparagine-linked glycosylation due to the presence of the APVNTA hexapeptide. (B) Quantification of the average secretory cargo fluorescence in cisternae of nocodazole-treated daughters at the time of maximal Sec7 signal. The Control measurements were performed using the glycosylated secretory cargo in unbleached cells, and the other three measurements were performed after recovery from bleaching as in Fig. 7. WT, cells with wild-type AP-1 and the glycosylated secretory cargo. The remaining two bars (for which virtually no signals were detected) are from the conditions described in A. Error bars represent SEM for measurements of at least four cisternae for each condition.