Figure 1.

(A) Scheme of the VPS52, VPS53, and VPS54 predicted ORFs. Regions with p > 0.5 of having coiled-coil structures as predicted by the COILS server are shaded. (B) CPY secretion in vps52, vps53, and vps54 mutants. The indicated strains were pulse labeled with [³⁵S]methionine for 10 min at 30°C and chased for another 60 min in the presence of 50 μg/ml each of cysteine and methionine. CPY was immunoprecipitated from intracellular (I) and extracellular (E) fractions, resolved by SDS-PAGE, and visualized by fluorography. (C) vps52, vps53, and vps54 mutants have an unusual vacuolar morphology. Log-phase cultures were incubated with CDCFDA for 45 min at 25°C. Representative cells from wild-type (left) or vps53 (right) strains are shown. The aberrant tubulovesicular vacuolar morphology was exhibited by the vast majority of vps52, vps53, and vps54 mutant cells.