The Amino Terminus of the Yeast F1-ATPase β-Subunit Precursor Functions as a Mitochondrial Import Signal

• Published in: The Journal of cell biology Vol. 102; no. 2; pp. 523 - 533
• Main Authors: Emr, Scott D., Vassarotti, Alessio, Garrett, Jinnie, Geller, Bruce L., Takeda, Masaharu, Douglas, Michael G.
• Format: Journal Article
• Language: English
• Published: New York, NY Rockefeller University Press 01-02-1986; The Rockefeller University Press
• Subjects: Amino Acid Sequence; Amino acids; Applied sciences; beta-Fructofuranosidase; beta-Galactosidase - genetics; Biological Transport; Cell Compartmentation; Cloning, Molecular; Cytochromes; DNA; DNA, Recombinant; Exact sciences and technology; Gene fusion; Genetic Vectors; Glycoside Hydrolases - genetics; Hybridity; Intracellular Membranes - metabolism; Macromolecular Substances; Mitochondria; Mitochondria - enzymology; Mitochondria - metabolism; Other techniques and industries; Phenotypes; Plasmids; Protein precursors; Proton-Translocating ATPases - genetics; Proton-Translocating ATPases - metabolism; Saccharomyces cerevisiae - metabolism; Saccharomyces cerevisiae - ultrastructure; Structure-Activity Relationship; Yeasts
• ISSN: 0021-9525; 1540-8140
• DOI: 10.1083/jcb.102.2.523

The ATP2 gene of Saccharomyces cerevisiae codes for the cytoplasmically synthesized β-subunit protein of the mitochondrial F1-ATPase. To define the amino acid sequence determinants necessary for the in vivo targeting and import of this protein into mitochondria, we have constructed gene fusions between the ATP2 gene and either the Escherichia coli lacZ gene or the S. cerevisiae SUC2 gene (which codes for invertase). The ATP2-lacZ and ATP2-SUC2 gene fusions code for hybrid proteins that are efficiently targeted to yeast mitochondria in vivo. The mitochondrially associated hybrid proteins fractionate with the inner mitochondrial membrane and are resistant to proteinase digestion in the isolated organelle. Results obtained with the gene fusions and with targeting-defective ATP2 deletion mutants provide evidence that the amino-terminal 27 amino acids of the β-subunit protein precursor are sufficient to direct both specific sorting of this protein to yeast mitochondria and its import into the organelle. Also, we have observed that certain of the mitochondrially associated Atp2-LacZ and Atp2-Suc2 hybrid proteins confer a novel respiration-defective phenotype to yeast cells.