Disruption of the outer membrane restores protein import to trypsin-treated yeast mitochondria.
Treatment of isolated yeast mitochondria with high levels (1 mg/ml) of trypsin severely inhibits protein import but does not destroy the integrity of the outer membrane or abolish mitochondrial energy coupling. If the outer membrane of these trypsin-inactivated mitochondria is disrupted by osmotic shock, the resulting mitoplasts are again able to import proteins. Protein import into mitoplasts, like that into intact mitochondria, is energy-dependent; however, whereas import into mitochondria is inhibited by antibody against 45-kd proteins of the outer membrane [Ohba and Schatz, EMBO J., 6, 2109-2115 (1987)], import into mitoplasts not affected by this antibody. Protein import into mitoplasts appears to bypass one or more steps normally occurring at the mitochondrial surface.
Ohba
M
M
Biocenter, University of Basel, Switzerland.
Schatz
G
G
D000906:Antibodies; D001692:Biological Transport / Q000187:drug effects; D007425:Intracellular Membranes / Q000187:drug effects / Q000378:metabolism*; D007700:Kinetics; D008564:Membrane Potentials; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism*; D008970:Molecular Weight; D011506:Proteins / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D014357:Trypsin / Q000494:pharmacology*
D000906:Antibodies; D011506:Proteins; D014357:Trypsin