Fig. 5.
Consequences of acute inhibition of the lectin chaperones. (A) Diagram illustrating the effect of Cst on Crt–substrate interactions. Cst inhibits both glucosidase I and II (GI/GII), preventing glucose trimming of glycosylated substrates. Newly synthesized glycoproteins (with three glucoses) cannot bind to Crt (indicated in green), whereas preexisting monoglucosylated glycoproteins remain substrates for Crt binding. The site of Puro action is also indicated. (B and C) FRAP analyses of Crt-GFP and ER-GFP were used to determine the Deff under the conditions indicated below the graph. The panels of Fig. 2 that correspond to each treatment condition are indicated in parentheses below the graph. Symbols above the bars indicate statistical significance (P < 0.005) between the following comparisons: ∗, Puro only versus Steady state; ∗∗, Cst only versus Steady state; #, Cst only versus dual treatments.