Protein import into the yeast mitochondrial matrix. A new translocation intermediate between the two mitochondrial membranes.
Import of authentic or artificial precursor proteins into the matrix of isolated yeast mitochondria can proceed via a translocation intermediate that is lodged between the two mitochondrial membranes. The intermediate accumulates when import is arrested by depleting mitochondria of ATP. Generation of the intermediate requires a potential across the inner membrane. The intermediate is membrane-bound, partly or completely processed (depending on the precursor), and chased into the matrix by added ATP. This chase does not require a potential across the inner membrane. The properties of this intermediate support the proposal (Hwang, S., Jascur, J., Vestweber, D., Pon, L., and Schatz, G. (1989) J. Cell Biol. 109, 487-493) that import into the matrix involves two distinct translocation systems in the outer and the inner mitochondrial membrane that are not permanently coupled to each other. Only translocation across the inner membrane requires ATP in the matrix.
Hwang
S T
ST
Biocenter, University of Basel, Switzerland.
Wachter
C
C
Schatz
G
G
D000255:Adenosine Triphosphate / Q000378:metabolism; D001693:Biological Transport, Active; D003576:Electron Transport Complex IV / Q000378:metabolism; D010450:Endopeptidases / Q000494:pharmacology; D005656:Fungal Proteins / Q000378:metabolism*; D006360:Heat-Shock Proteins / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007425:Intracellular Membranes / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism; D008928:Mitochondria / Q000378:metabolism*; D011487:Protein Conformation; D011498:Protein Precursors / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012441:Saccharomyces cerevisiae
D005656:Fungal Proteins; D006360:Heat-Shock Proteins; D008565:Membrane Proteins; D011498:Protein Precursors; D011993:Recombinant Fusion Proteins; D000255:Adenosine Triphosphate; D003576:Electron Transport Complex IV; D010450:Endopeptidases