Abstract
Cytochrome c oxidase subunit II (Cox2p) of Saccharomyces cerevisiae is synthesized within mitochondria as a precursor, pre-Cox2p. The 15-amino acid leader peptide is processed after export to the intermembrane space. Leader peptides are relatively unusual in mitochondrially coded proteins: indeed mammalian Cox2p lacks a leader peptide. We generated two deletions in the S. cerevisiae COX2 gene, removing either the leader peptide (cox2-20) or the leader peptide and processing site (cox2-21) without altering either the promoter or the mRNA-specific translational activation site. When inserted into mtDNA, both deletions substantially reduced the steady-state levels of Cox2p and caused a tight nonrespiratory phenotype. A respiring pseudorevertant of the cox2-20 mutant was heteroplasmic for the original mutant mtDNA and a ρ(-) mtDNA whose deletion fused the first 251 codons of the mitochondrial gene encoding cytochrome b to the cox2-20 sequence. The resulting fusion protein was processed to yield functional Cox2p. Thus, the presence of amino-terminal cytochrome b sequence bypassed the need for the pre-Cox2p leader peptide. We propose that the pre-Cox2p leader peptide contains a targeting signal necessary for membrane insertion, without which it remains in the matrix and is rapidly degraded.
Full Text
The Full Text of this article is available as a PDF (4.7 MB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Anderson S., de Bruijn M. H., Coulson A. R., Eperon I. C., Sanger F., Young I. G. Complete sequence of bovine mitochondrial DNA. Conserved features of the mammalian mitochondrial genome. J Mol Biol. 1982 Apr 25;156(4):683–717. doi: 10.1016/0022-2836(82)90137-1. [DOI] [PubMed] [Google Scholar]
- Attardi G., Schatz G. Biogenesis of mitochondria. Annu Rev Cell Biol. 1988;4:289–333. doi: 10.1146/annurev.cb.04.110188.001445. [DOI] [PubMed] [Google Scholar]
- Behrens M., Michaelis G., Pratje E. Mitochondrial inner membrane protease 1 of Saccharomyces cerevisiae shows sequence similarity to the Escherichia coli leader peptidase. Mol Gen Genet. 1991 Aug;228(1-2):167–176. doi: 10.1007/BF00282462. [DOI] [PubMed] [Google Scholar]
- Bordonné R., Dirheimer G., Martin R. P. Expression of the oxi1 and maturase-related RF1 genes in yeast mitochondria. Curr Genet. 1988 Mar;13(3):227–233. doi: 10.1007/BF00387768. [DOI] [PubMed] [Google Scholar]
- Cameron V. L., Fox T. D., Poyton R. O. Isolation and characterization of a yeast strain carrying a mutation in the mitochondrial promoter for COX2. J Biol Chem. 1989 Aug 15;264(23):13391–13394. [PubMed] [Google Scholar]
- Conde J., Fink G. R. A mutant of Saccharomyces cerevisiae defective for nuclear fusion. Proc Natl Acad Sci U S A. 1976 Oct;73(10):3651–3655. doi: 10.1073/pnas.73.10.3651. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Costanzo M. C., Fox T. D. Suppression of a defect in the 5' untranslated leader of mitochondrial COX3 mRNA by a mutation affecting an mRNA-specific translational activator protein. Mol Cell Biol. 1993 Aug;13(8):4806–4813. doi: 10.1128/mcb.13.8.4806. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Derman A. I., Puziss J. W., Bassford P. J., Jr, Beckwith J. A signal sequence is not required for protein export in prlA mutants of Escherichia coli. EMBO J. 1993 Mar;12(3):879–888. doi: 10.1002/j.1460-2075.1993.tb05728.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Dieckmann C. L., Staples R. R. Regulation of mitochondrial gene expression in Saccharomyces cerevisiae. Int Rev Cytol. 1994;152:145–181. doi: 10.1016/s0074-7696(08)62556-5. [DOI] [PubMed] [Google Scholar]
- Fearnley I. M., Walker J. E. Two overlapping genes in bovine mitochondrial DNA encode membrane components of ATP synthase. EMBO J. 1986 Aug;5(8):2003–2008. doi: 10.1002/j.1460-2075.1986.tb04456.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Folley L. S., Fox T. D. Site-directed mutagenesis of a Saccharomyces cerevisiae mitochondrial translation initiation codon. Genetics. 1991 Nov;129(3):659–668. doi: 10.1093/genetics/129.3.659. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Fox T. D. Five TGA "stop" codons occur within the translated sequence of the yeast mitochondrial gene for cytochrome c oxidase subunit II. Proc Natl Acad Sci U S A. 1979 Dec;76(12):6534–6538. doi: 10.1073/pnas.76.12.6534. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Fox T. D. Genetic and physical analysis of the mitochondrial gene for subunit II of yeast cytochrome c oxidase. J Mol Biol. 1979 May 5;130(1):63–82. doi: 10.1016/0022-2836(79)90552-7. [DOI] [PubMed] [Google Scholar]
- Fox T. D., Sanford J. C., McMullin T. W. Plasmids can stably transform yeast mitochondria lacking endogenous mtDNA. Proc Natl Acad Sci U S A. 1988 Oct;85(19):7288–7292. doi: 10.1073/pnas.85.19.7288. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Gavel Y., von Heijne G. The distribution of charged amino acids in mitochondrial inner-membrane proteins suggests different modes of membrane integration for nuclearly and mitochondrially encoded proteins. Eur J Biochem. 1992 May 1;205(3):1207–1215. doi: 10.1111/j.1432-1033.1992.tb16892.x. [DOI] [PubMed] [Google Scholar]
- Glick B. S., Von Heijne G. Saccharomyces cerevisiae mitochondria lack a bacterial-type sec machinery. Protein Sci. 1996 Dec;5(12):2651–2652. doi: 10.1002/pro.5560051229. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hardy C. M., Clark-Walker G. D. Nucleotide sequence of the cytochrome oxidase subunit 2 and val-tRNA genes and surrounding sequences from Kluyveromyces lactis K8 mitochondrial DNA. Yeast. 1990 Sep-Oct;6(5):403–410. doi: 10.1002/yea.320060505. [DOI] [PubMed] [Google Scholar]
- Herrmann J. M., Koll H., Cook R. A., Neupert W., Stuart R. A. Topogenesis of cytochrome oxidase subunit II. Mechanisms of protein export from the mitochondrial matrix. J Biol Chem. 1995 Nov 10;270(45):27079–27086. doi: 10.1074/jbc.270.45.27079. [DOI] [PubMed] [Google Scholar]
- Hoffman C. S., Winston F. A ten-minute DNA preparation from yeast efficiently releases autonomous plasmids for transformation of Escherichia coli. Gene. 1987;57(2-3):267–272. doi: 10.1016/0378-1119(87)90131-4. [DOI] [PubMed] [Google Scholar]
- Leonhardt S. A., Fearson K., Danese P. N., Mason T. L. HSP78 encodes a yeast mitochondrial heat shock protein in the Clp family of ATP-dependent proteases. Mol Cell Biol. 1993 Oct;13(10):6304–6313. doi: 10.1128/mcb.13.10.6304. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lu B., Hanson M. R. A single homogeneous form of ATP6 protein accumulates in petunia mitochondria despite the presence of differentially edited atp6 transcripts. Plant Cell. 1994 Dec;6(12):1955–1968. doi: 10.1105/tpc.6.12.1955. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Mannhaupt G., Beyreuther K., Michaelis G. Cytochrome b, the var 1 protein, and subunits I and III of cytochrome c oxidase are synthesized without transient presequences in Saccharomyces cerevisiae. Eur J Biochem. 1985 Aug 1;150(3):435–439. doi: 10.1111/j.1432-1033.1985.tb09039.x. [DOI] [PubMed] [Google Scholar]
- Michon T., Galante M., Velours J. NH2-terminal sequence of the isolated yeast ATP synthase subunit 6 reveals post-translational cleavage. Eur J Biochem. 1988 Mar 15;172(3):621–625. doi: 10.1111/j.1432-1033.1988.tb13934.x. [DOI] [PubMed] [Google Scholar]
- Mulero J. J., Fox T. D. Alteration of the Saccharomyces cerevisiae COX2 mRNA 5'-untranslated leader by mitochondrial gene replacement and functional interaction with the translational activator protein PET111. Mol Biol Cell. 1993 Dec;4(12):1327–1335. doi: 10.1091/mbc.4.12.1327. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Mulero J. J., Fox T. D. PET111 acts in the 5'-leader of the Saccharomyces cerevisiae mitochondrial COX2 mRNA to promote its translation. Genetics. 1993 Mar;133(3):509–516. doi: 10.1093/genetics/133.3.509. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Nakai T., Yasuhara T., Fujiki Y., Ohashi A. Multiple genes, including a member of the AAA family, are essential for degradation of unassembled subunit 2 of cytochrome c oxidase in yeast mitochondria. Mol Cell Biol. 1995 Aug;15(8):4441–4452. doi: 10.1128/mcb.15.8.4441. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Nobrega F. G., Tzagoloff A. Assembly of the mitochondrial membrane system. DNA sequence and organization of the cytochrome b gene in Saccharomyces cerevisiae D273-10B. J Biol Chem. 1980 Oct 25;255(20):9828–9837. [PubMed] [Google Scholar]
- Nunnari J., Fox T. D., Walter P. A mitochondrial protease with two catalytic subunits of nonoverlapping specificities. Science. 1993 Dec 24;262(5142):1997–2004. doi: 10.1126/science.8266095. [DOI] [PubMed] [Google Scholar]
- Pearce D. A., Sherman F. Degradation of cytochrome oxidase subunits in mutants of yeast lacking cytochrome c and suppression of the degradation by mutation of yme1. J Biol Chem. 1995 Sep 8;270(36):20879–20882. doi: 10.1074/jbc.270.36.20879. [DOI] [PubMed] [Google Scholar]
- Poutre C. G., Fox T. D. PET111, a Saccharomyces cerevisiae nuclear gene required for translation of the mitochondrial mRNA encoding cytochrome c oxidase subunit II. Genetics. 1987 Apr;115(4):637–647. doi: 10.1093/genetics/115.4.637. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Poyton R. O., Duhl D. M., Clarkson G. H. Protein export from the mitochondrial matrix. Trends Cell Biol. 1992 Dec;2(12):369–375. doi: 10.1016/0962-8924(92)90049-s. [DOI] [PubMed] [Google Scholar]
- Pratje E., Mannhaupt G., Michaelis G., Beyreuther K. A nuclear mutation prevents processing of a mitochondrially encoded membrane protein in Saccharomyces cerevisiae. EMBO J. 1983;2(7):1049–1054. doi: 10.1002/j.1460-2075.1983.tb01544.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Schatz G., Dobberstein B. Common principles of protein translocation across membranes. Science. 1996 Mar 15;271(5255):1519–1526. doi: 10.1126/science.271.5255.1519. [DOI] [PubMed] [Google Scholar]
- Schneider A., Behrens M., Scherer P., Pratje E., Michaelis G., Schatz G. Inner membrane protease I, an enzyme mediating intramitochondrial protein sorting in yeast. EMBO J. 1991 Feb;10(2):247–254. doi: 10.1002/j.1460-2075.1991.tb07944.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Steele D. F., Butler C. A., Fox T. D. Expression of a recoded nuclear gene inserted into yeast mitochondrial DNA is limited by mRNA-specific translational activation. Proc Natl Acad Sci U S A. 1996 May 28;93(11):5253–5257. doi: 10.1073/pnas.93.11.5253. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Steffens G. J., Buse G. Studies on cytochrome c oxidase, IV[1--3]. Primary structure and function of subunit II. Hoppe Seylers Z Physiol Chem. 1979 Apr;360(4):613–619. [PubMed] [Google Scholar]
- Trumpower B. L. Cytochrome bc1 complexes of microorganisms. Microbiol Rev. 1990 Jun;54(2):101–129. doi: 10.1128/mr.54.2.101-129.1990. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Tzagoloff A., Yue J., Jang J., Paul M. F. A new member of a family of ATPases is essential for assembly of mitochondrial respiratory chain and ATP synthetase complexes in Saccharomyces cerevisiae. J Biol Chem. 1994 Oct 21;269(42):26144–26151. [PubMed] [Google Scholar]
- Van Dyck L., Pearce D. A., Sherman F. PIM1 encodes a mitochondrial ATP-dependent protease that is required for mitochondrial function in the yeast Saccharomyces cerevisiae. J Biol Chem. 1994 Jan 7;269(1):238–242. [PubMed] [Google Scholar]
- Weber E. R., Hanekamp T., Thorsness P. E. Biochemical and functional analysis of the YME1 gene product, an ATP and zinc-dependent mitochondrial protease from S. cerevisiae. Mol Biol Cell. 1996 Feb;7(2):307–317. doi: 10.1091/mbc.7.2.307. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wickner W., Driessen A. J., Hartl F. U. The enzymology of protein translocation across the Escherichia coli plasma membrane. Annu Rev Biochem. 1991;60:101–124. doi: 10.1146/annurev.bi.60.070191.000533. [DOI] [PubMed] [Google Scholar]
- Wilson T. M., Cameron V. Replacement of a conserved glycine residue in subunit II of cytochrome c oxidase interferes with protein function. Curr Genet. 1994 Mar;25(3):233–238. doi: 10.1007/BF00357167. [DOI] [PubMed] [Google Scholar]
- Yaffe M. P. Analysis of mitochondrial function and assembly. Methods Enzymol. 1991;194:627–643. doi: 10.1016/0076-6879(91)94046-f. [DOI] [PubMed] [Google Scholar]
- van den Boogaart P., van Dijk S., Agsteribbe E. The mitochondrially made subunit 2 of Neurospora crassa cytochrome aa3 is synthesized as a precursor protein. FEBS Lett. 1982 Oct 4;147(1):97–100. doi: 10.1016/0014-5793(82)81019-3. [DOI] [PubMed] [Google Scholar]