FIG. 10.

Overproduction of Tom6 suppresses Tom22 assembly and improves import phenotypes of sam37Δ cells. (A) Radiolabeled precursor of Tom22 was incubated with various mitochondria as described in the legend to Fig. 9A. Either samples were extracted with carbonate and pellets were analyzed by sodium dodecyl sulfate (SDS)-PAGE and autoradiography, or they were solubilized with 1% digitonin and analyzed by BN-PAGE and autoradiography. Bands corresponding to assembled TOM complex are indicated. The bands corresponding to Tom22 in the carbonate pellet (import) and assembled Tom22 (assembly, assayed by BN-PAGE) were quantified. The amount of protein imported into or assembled within mitochondria isolated from wild-type (WT) cells after the longest incubation period was set to 100%. An average for three experiments is presented. (B) Radiolabeled precursor of pSu9-DHFR was incubated with various mitochondria as described in the legend to Fig. 9A. Samples were treated with proteinase K, mitochondria were reisolated, and imported proteins were analyzed by SDS-PAGE and autoradiography. The precursor and mature forms are indicated by p and m, respectively. The bands corresponding to the mature form were quantified, and the amount of protein imported into mitochondria isolated from wild-type cells for the longest time period was set to 100%.