Protein import into yeast mitochondria is accelerated by the outer membrane protein MAS70.

V Hines, Anders Brandt, G Griffiths, H Horstmann, H Brütsch, G Schatz

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

The yeast mitochondrial outer membrane contains a major 70 kd protein with an amino-terminal hydrophobic membrane anchor and a hydrophilic 60 kd domain exposed to the cytosol. We now show that this protein (which we term MAS70) accelerates the mitochondrial import of many (but not all) precursor proteins. Anti-MAS70 IgGs or removal of MAS70 from the mitochondria by either mild trypsin treatment or by disrupting the nuclear MAS70 gene inhibits import of the F1-ATPase beta-subunit, the ADP/ATP translocator, and of several other precursors into isolated mitochondria by up to 75%, but has little effect on the import of porin. Intact cells of a mas70 null mutant import the F1-ATPase alpha-subunit and beta-subunits, cytochrome c1 and other precursors at least several fold more slowly than wild-type cells. Removal of MAS70 from wild-type mitochondria inhibits binding of the ADP/ATP translocator to the mitochondrial surface, indicating that MAS70 mediates one of the earliest import steps. Several precursors are thus imported by a pathway in which MAS70 functions as a receptor-like component. MAS70 is not essential for import of these precursors, but only accelerates this process.
Original languageEnglish
JournalE M B O Journal
Volume9
Issue number10
Pages (from-to)3191-3200
ISSN0261-4189
Publication statusPublished - 1990
Externally publishedYes

Fingerprint Dive into the research topics of 'Protein import into yeast mitochondria is accelerated by the outer membrane protein MAS70.'. Together they form a unique fingerprint.

Cite this