FIG. 7.

Internalization of the α-factor receptor and of the maltose transporter in a mutant deficient in Sec23p. Strains RH448 (wild type; ○) and RH1416 (sec23-1; ▵), transformed with the plasmid pRM1-1 carrying the MAL1 locus, were grown and treated as described in the legend for Fig. 1. After incubation at 24 or 32°C for the indicated times, the cells were harvested and assayed for internalization of the α-factor receptor with ³⁵S-labeled α-factor (A and B). Internalization of the maltose transporter was monitored in parallel experiments by measuring the decrease in transport activity (C and D). Data of two experiments are shown.