Figure 5.

Glycopeptide export across the ER membrane requires ATP in the ER lumen. (Upper) DIDS inhibits glycopeptide export from the ER. Wild-type (RSY255) microsomes were translocated with ¹²⁵I-Ac-NYT-NH₂, washed with B88 containing the indicated concentration of DIDS, and glycopeptide export in the presence of the indicated concentrations of DIDS assayed in duplicate as described in Fig. 1. (Lower) Δsac1 microsomes are defective in glycopeptide export from the ER. Microsomes were prepared from wild-type (SAC1) and Δsac1 cells and glycopeptide export assayed as described in Fig. 1.