Localization of prenylation substrates Ras1 and Cdc42 is not impaired by loss of the postprenylation processing enzymes. To compare the membrane localization of Ras1 and Cdc42 in the postprenylation processing mutants, wild-type and mutant strains expressing mCh-RAS1 (top) or GFP-CDC42 (bottom) were incubated overnight in YPD, diluted 10-fold, and grown for 4 h at 25°C. (Top) mCh-Ras1 expression in wild-type (CBN121), rce1Δ (LKA7), rce1Δ ste24Δ (CBN48), and ste14Δ (CBN308) strains. (Bottom) Gfp-Cdc42 expression in wild-type (CBN302), rce1Δ (SKE15), rce1Δ ste24Δ (SKE22), and ste14Δ (SKE53) strains. Cells were imaged by fluorescence microscopy (Zeiss Axio Imager A1) using the appropriate filter. Bar, 5 µm.