Import of transcription factor MTF1 into the yeast mitochondria takes place through an unusual pathway.
We report studies of the import into mitochondria of MTF1, a nucleus-encoded factor that markedly stimulates the specific transcription of mitochondrial DNA. Unlike most of the mitochondrial precursor proteins studied so far, import of MTF1 does not appear to require a receptor on the outer membrane, membrane potential across the inner membrane, or ATP hydrolysis. Its import is not affected by low temperature. It lacks a cleavable presequence but translocates across the inner membrane through its amino terminus; its sorting is independent of hsp60. Our results indicate an unusual and distinct import pathway for MTF1 into the yeast mitochondria.
Sanyal
A
A
Deparment of Pathology, University of Chicago, Illinois 60637, USA.
Getz
G S
GS
D001692:Biological Transport / Q000187:drug effects; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone / Q000494:pharmacology; D002467:Cell Nucleus / Q000378:metabolism; D004072:Digitonin / Q000494:pharmacology; D004492:Edetic Acid / Q000494:pharmacology; D019286:Endopeptidase K; D005656:Fungal Proteins / Q000378:metabolism*; D007425:Intracellular Membranes / Q000187:drug effects / Q000378:metabolism; D008564:Membrane Potentials; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism*; D024101:Mitochondrial Proteins; D010618:Phenanthrolines / Q000494:pharmacology; D011498:Protein Precursors / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins; D012697:Serine Endopeptidases / Q000494:pharmacology; D013696:Temperature; D014157:Transcription Factors / Q000378:metabolism*; D014357:Trypsin / Q000494:pharmacology; D014634:Valinomycin / Q000494:pharmacology
D005656:Fungal Proteins; C071720:MTF1 protein, S cerevisiae; D024101:Mitochondrial Proteins; D010618:Phenanthrolines; D011498:Protein Precursors; D011993:Recombinant Fusion Proteins; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D014634:Valinomycin; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone; D004492:Edetic Acid; D012697:Serine Endopeptidases; D014357:Trypsin; D019286:Endopeptidase K; D004072:Digitonin; C025205:1,10-phenanthroline