FIGURE 4.

Vid24p interacts with coatomer. A, wild type cells expressing Vid24p-HA were glucose starved and then shifted to glucose for 0, 30, and 60 min. Levels of coatomer proteins in total lysates were determined by immunoblotting. B, lysates were further separated into vesicle (V) and cytosol (C) fractions. The amounts of coatomer proteins in each fraction were determined by Western blotting. C, Vid vesicle fractions were solubilized with Triton X-100 and immunoprecipitated with HA antibodies. The unbound and bound fractions were immunoblotted with anti-HA and anti-coatomer antibodies. D, wild type, Δsec28, sec21-1, and ret2-1 strains were grown in YPKG at 24 °C and cells were shifted to glucose at 37 °C for 30 min. The distributions of Vid24p and α-COP in the cytosol and Vid vesicle-enriched fractions were examined in these mutants. E, Sec28p and α-COP distributions in the cytosol and Vid vesicle-enriched fractions of Δvam3, Δvid24, and sec21-1 cells were determined.