Figure 3.

Both Egd2p and Mft52p are involved in mitochondrial biogenesis. (a) Heterozygous (EGD2/Δegd2, MFT1/Δmft1) diploid yeast cells were sporulated, tetrads were dissected, and cells were incubated at 30°C on rich Glc medium for 2 days. (b) Mitochondria were prepared from wild-type (lane 1), Δegd2 (lane 2), Δmft1 (lane 3), and Δegd2, Δmft1 (lane 4) yeast cells expressing CoxIV-DHFR. DHFR delivered to the mitochondria was measured by immunoblotting after SDS/PAGE. The blots were reprobed with antisera recognizing cytochrome b₂. DHFR delivered to mitochondria was quantitated by densitometry and is expressed as a percentage of the wild-type level of DHFR:cytochrome b₂. (c) Wild-type (diploid) yeast cells were transformed to express CoxIV-GFP. The cells were viewed with Nomarski optics and analyzed by fluorescence microscopy. (d) The homozygous diploid Δegd2, Δmft1 cells.