Figures & data
Table 1. The localization of import components within respiratory complexes in plant mitochondria. The locations of import components, Preprotein and Amino acid Transporters (PRAT) and Complex I subunits in the Arabidopsis mitochondrial protein complex proteome, as shown in Klodmann et al., 2011 and Wang et al., 2012. The PRAT components and import components are indicated in bold
Figure 1. Diagrammatic representation of the interaction between Tim23–2 and Complex I in Arabidopsis mitochondria. Top left panel – Static – represents the TOM, TIM and respiratory complexes I and III as defined by biochemical and genetic studies. The bottom left panel – Dynamic- represents the interactions between the complexes, and Tim21 and Tim23. Imported Tim23 is incorporated into Complex I, and imported Tim21 is incorporated into Complex III. However, as most of the Tim23 and Tim21 proteins are present in the TIM17:23 complex, and the respiratory complexes are more abundant than TIM17:23 complexes, the association of Tim23 and Tim21 with Complex I and Complex III is not in stoichiometric levels, indicated in blue. A supercomplex of complex I+III is indicated, which does not contain Tim23, Tim21 or the Complex I subunit B14.7. The right panel shows what happens when an increase in Tim23–2 or decrease in Complex I occurs. There is an increase in the Tom20 receptors proteins and proteins of the TIM17:23sort complex, indicated in red. Monomeric Complex I is almost completely absent, as indicated by open blue symbols, and the super-complex I+III is reduced in abundance, indicated in blue. In addition, there are global changes in the cell transcriptome, which includes an increase in mitochondrial transcription and translation, constituting mitochondrial biogenesis.
