Figure 3.

Left. A WT mitochondrion is shown with an intact CI–CV ETC chain (red squares). The five subunits of the ETC are shown as rectangles. As for the individual subunit proteins of CI mentioned below, Ndh51p is critically located at the ubiquinone reduction site within the CI where other NADH oxidoreductases are located. The location of Nuo1p and Nuo2p is not known. Right. The outer/inner membranes are shown. In the CI mutants as well as goa1Δ, a loss (disassembly) of the CI complex from the inner membrane is depicted. The CI in the WT is represented as larger in molecular mass versus the other complexes. For each mutant, the disassembly of the CI is represented. Table below. Upregulated and downregulated genes in each of the CI mutants and in the putative CI regulator (goa1Δ) are listed for specific gene categories. Nuo1p and Nuo2p are nearly functionally redundant. All of the mutants except goa1Δ have major upregulation in genes of the ETC complexes, except CI (left column). These data may suggest that mutants have ETC compensatory activities that include one of the two alternate oxidases AOX2 and the NDE1.