Figure 7.

 Overexpression of Far1p is lethal in skp1 mutants in an allele-specific fashion and Far1p accumulates in cdc34 mutants independent of the cell cycle stage. (A) The effect of overexpression of Far1p was tested in specific temperature-sensitive alleles of SKP1 that either cause arrest in G₁ (skp1-11, Y552) or in G₂ (skp1-12, Y554) as described in Fig. 6. Only cells harboring the G₁-specific allele of SKP1 were arrested by overexpression of wild-type Far1p. (B) Far1p accumulates in cdc34 (YMT670) and cdc34 Δsic1 cells (ES464). The indicated strains were arrested at 37°C and the accumulation of a Far1–LacZ fusion protein was quantified and plotted as Miller Units deduced from three independent experiments. Note that Far1–LacZp accumulates in cdc34 mutants independently of the cell cycle arrest point; no accumulation was observed in cdc16 cells or cells deleted for SIC1. (C) Far1-22–LacZp accumulates in wild-type (K699) and cdc16 (K4102) mutant cells but is produced at levels similar to wild-type Far1–LacZp in cdc34 (YMT670) and cdc34 Δsic1 (ES464) cells.