Figure 6.

Trafficking of VSV-G from the ER to medial-Golgi in PITPα +/+ and −/− cells. The mutant VSV-G tsO45 protein was accumulated in the ER of infected cells (genotypes at left) at 39.5°C and chase was initiated by adding cycloheximide and reducing culture temperature to 32°C (t = 0 min). VSV-G tsO45 was chased from the ER for various times (top). Samples were collected and either challenged with endoglycosidase H (+) or not (−) as indicated at bottom. EndoH resistance signifies arrival in medial-Golgi, and the fraction of EndoH-resistant VSV-G tsO45 increases with chase. EndoH sensitivity is scored by increased migration of VSV-G tsO45 after EndoH challenge. Quantification of the fraction of VSV-G tsO45 that has acquired EndoH resistance at each time point is given at bottom. One set of quantifications is given because values were essentially identical for +/+ and −/− cells.