Figure 4
Mitochondrial protein synthesis in pet mutants showing an altered translation pattern. Yeast strains were grown in raffinose-containing minimal medium to logarithmic growth phase, cytosolic translation was stopped by the addition of cycloheximide, and newly synthesized mitochondrial proteins were labeled by the addition of 35S methionine. After an incubation of 30 minutes at 30°C, labeling of mitochondrial proteins was stopped by the addition of cold methionine and chloramphenicol, and cell extracts were analyzed by SDS-PAGE, transfer of proteins to nitrocellulose and autoradiography. All mutants have been analyzed in at least three independent experiments. The samples shown here have all been analyzed on the same gel (one lane has been spliced out as indicated by the thin line between lanes 3 and 4). For each strain the same amount of total cellular protein has been loaded per lane. Mutants that were previously not known to be affected in the synthesis of specific mitochondria-encoded proteins are in bold letters. Alterations of the translation pattern mentioned in the text are marked with asterisks. Black asterisks mark bands that are absent, and the white asterisk marks an additional band present in Δcyc3. WT, wild type.