Degradation of Cytochrome Oxidase Subunits in Mutants of Yeast Lacking Cytochrome c and Suppression of the Degradation by Mutation of yme1(*)
- From the Department of Biochemistry, University of Rochester School of Medicine and Dentistry, Rochester, New York 14642
- § To whom correspondence should be addressed. Tel.: 716-275-2766; Fax: 716-271-2683;
Abstract
We have confirmed by spectral analysis that cytochrome oxidase is not present in strains of the yeast Saccharomyces cerevisiae having a primary deficiency in cytochrome c, and we have demonstrated by immunological procedures that such strains lack the mitochondrially encoded subunits I, II,
and III of cytochrome oxidase. Furthermore, pulse-chase experiments demonstrated that subunit II is rapidly degraded in vivo. This degradation can be at least partially suppressed by disruption of the nuclear gene YME1, which encodes a putative ATP-Zn
-dependent protease. We suggest that the cytochrome oxidase subunits are not properly assembled in the absence of cytochrome
c, and that Yme1 and possibly other proteases degrade the unassembled mitochondrial-encoded subunits of cytochrome oxidase.
Footnotes
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↵* This work was supported in part by National Institutes of Health Grant RO1 GM 12702 and in part by National Science Foundation Grant CHE9123792. The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore by hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
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↵1L. Calavetta and R. A. Capaldi, manuscript in preparation.
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↵2E. R. Weber, T. Hanekamp, and P. E. Thorsness, manuscript in preparation.
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- Received June 8, 1995.
- © 1995 by The American Society for Biochemistry and Molecular Biology, Inc.
