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Yeast mitochondrial ATPase subunit 8, normally a mitochondrial gene product, expressed in vitro and imported back into the organelle.
Author(s) -
Gearing D.P.,
Nagley P.
Publication year - 1986
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1002/j.1460-2075.1986.tb04695.x
Subject(s) - biology , organelle , protein subunit , mitochondrion , gene , yeast , atpase , mitochondrial dna , gene product , microbiology and biotechnology , in vitro , genetics , gene expression , biochemistry , enzyme
Subunit 8 of yeast mitochondrial F1F0‐ATPase is a proteolipid made on mitochondrial ribosomes and inserted directly into the inner membrane for assembly with the other F0 membrane‐sector components. We have investigated the possibility of expressing this extremely hydrophobic, mitochondrially encoded protein outside the organelle and directing its import back into mitochondria using a suitable N‐terminal targeting presequence. This report describes the successful import in vitro of ATPase subunit 8 proteolipid into yeast mitochondria when fused to the targeting sequence derived from the precursor of Neurospora crassa ATPase subunit 9. The predicted cleavage site of matrix protease was correctly recognized in the fusion protein. A targeting sequence from the precursor of yeast cytochrome oxidase subunit VI was unable to direct the subunit 8 proteolipid into mitochondria. The proteolipid subunit 8 exhibited a strong tendency to embed itself in mitochondrial membranes, which interfered with its ability to be properly imported when part of a synthetic precursor.