Protein import into plant mitochondria: precursor proteins differ in ATP and membrane potential requirements.
The import pathways of the alternative oxidase and the F(A)d subunit of the ATP synthase from soybean were characterised. The F(A)d precursor does not require extramitochondrial ATP for import and this was shown to be a characteristic of the mature protein. The alternative oxidase and F(A)d precursors were shown to differ in their requirement for a membrane potential. The membrane potential was modified using malonate, a competitive inhibitor to complex II. The alternative oxidase could be imported at higher malonate concentrations compared to the F(A)d. This difference could not be ascribed to the number of positive charges in each presequence as would be predicted from similar studies in fungi.
Tanudji
M
M
Department of Biochemistry, University of Western Australia, Nedlands, Australia.
Dessi
P
P
Murcha
M
M
Whelan
J
J
D000255:Adenosine Triphosphate / Q000378:metabolism; D001692:Biological Transport; D004792:Enzyme Precursors / Q000378:metabolism; D007425:Intracellular Membranes / Q000502:physiology; D008564:Membrane Potentials; D008928:Mitochondria / Q000378:metabolism*; D024101:Mitochondrial Proteins; D010088:Oxidoreductases / Q000378:metabolism; D010940:Plant Proteins / Q000378:metabolism*; D011499:Protein Processing, Post-Translational; D021122:Protein Subunits; D006180:Proton-Translocating ATPases / Q000378:metabolism; D013025:Glycine max; D000099188:Alternative Oxidase
D000255:Adenosine Triphosphate; D004792:Enzyme Precursors; D024101:Mitochondrial Proteins; D010088:Oxidoreductases; D010940:Plant Proteins; D021122:Protein Subunits; D006180:Proton-Translocating ATPases; D000099188:Alternative Oxidase