The protein import receptor MOM19 of yeast mitochondria.
We have identified the protein import receptor MOM19 of Saccharomyces cerevisiae mitochondria. MOM19 is exposed on the outer membrane surface and present in the mitochondrial receptor complex. Antibodies raised against MOM19 strongly inhibited the import of preproteins into isolated yeast mitochondria. Fab fragments prepared from the antibodies showed the same inhibitory effect. By using mutant mitochondria, which lacked the second import receptor MOM72, we found that the import of preproteins via MOM19 did not require the presence of MOM72. We conclude that MOM19 is required for preprotein translocation across the yeast mitochondrial outer membrane and is able to function independently of the receptor MOM72.
Moczko
M
M
Biochemisches Institut, Universität Freiburg, Germany.
Gärtner
F
F
Pfanner
N
N
D000906:Antibodies; D001692:Biological Transport; D005656:Fungal Proteins / Q000378:metabolism; D007140:Immunoglobulin Fab Fragments; D008565:Membrane Proteins; D008928:Mitochondria / Q000378:metabolism*; D033681:Mitochondrial Membrane Transport Proteins; D000090622:Mitochondrial Precursor Protein Import Complex Proteins; D009154:Mutation; D009492:Neurospora crassa / Q000737:chemistry; D011498:Protein Precursors / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification / Q000502:physiology*; D018160:Receptors, Cytoplasmic and Nuclear; D012441:Saccharomyces cerevisiae / Q000737:chemistry / Q000648:ultrastructure*; D029701:Saccharomyces cerevisiae Proteins; D014357:Trypsin / Q000378:metabolism
D000906:Antibodies; D005656:Fungal Proteins; D007140:Immunoglobulin Fab Fragments; D008565:Membrane Proteins; D033681:Mitochondrial Membrane Transport Proteins; D000090622:Mitochondrial Precursor Protein Import Complex Proteins; D011498:Protein Precursors; D011956:Receptors, Cell Surface; D018160:Receptors, Cytoplasmic and Nuclear; D029701:Saccharomyces cerevisiae Proteins; C489350:TOM20 protein, S cerevisiae; C489039:TOM70 protein, S cerevisiae; D014357:Trypsin