+ Site Statistics
References:
52,654,530
Abstracts:
29,560,856
PMIDs:
28,072,755
+ Search Articles
+ Subscribe to Site Feeds
Most Shared
PDF Full Text
+ PDF Full Text
Request PDF Full Text
+ Follow Us
Follow on Facebook
Follow on Twitter
Follow on LinkedIn
+ Translate
+ Recently Requested

Deletion of the leader peptide of the mitochondrially encoded precursor of Saccharomyces cerevisiae cytochrome c oxidase subunit II



Deletion of the leader peptide of the mitochondrially encoded precursor of Saccharomyces cerevisiae cytochrome c oxidase subunit II



Genetics 145(4): 903-910



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. cereuisiae 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 rho- 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 preCox2p 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.

(PDF emailed within 1 workday: $29.90)

Accession: 008427269

Download citation: RISBibTeXText

PMID: 9093845


Related references

Rpm2, the protein subunit of mitochondrial RNase P in Saccharomyces cerevisiae, also has a role in the translation of mitochondrially encoded subunits of cytochrome c oxidase. Genetics 158(2): 573-585, 2001

Translocation and assembly of mitochondrially coded Saccharomyces cerevisiae cytochrome c oxidase subunit Cox2 by Oxa1 and Yme1 in the absence of Cox18. Genetics 182(2): 519-528, 2009

Thyroid hormone and dexamethasone increase the levels of a messenger ribonucleic acid for a mitochondrially encoded subunit but not for a nuclear-encoded subunit of cytochrome c oxidase. Endocrinology 127(1): 55-62, 1990

Mitochondrial assembly in respiration-deficient mutants of Saccharomyces cerevisiae. IV. Effects of nuclear amber suppressors on the accumulation of a mitochondrially made subunit of cytochrome c oxidase. Journal of Biological Chemistry 250(2): 775-782, 1975

A messenger rna maturase is encoded by the 1st intron of the mitochondrial gene for the subunit i of cytochrome oxidase in saccharomyces cerevisiae. Cell 35(3 PART 2): 733-742, 1983

An mRNA maturase is encoded by the first intron of the mitochondrial gene for the subunit 1 of cytochrome oxidase in Saccharomyces cerevisiae. Cell 35(2): 733-742, 1983

CBT1 interacts genetically with CBP1 and the mitochondrially encoded cytochrome b gene and is required to stabilize the mature cytochrome b mRNA of Saccharomyces cerevisiae. Genetics 171(3): 949-957, 2005

Deletion of the COX7 gene in Saccharomyces cerevisiae reveals a role for cytochrome c oxidase subunit VII in assembly of remaining subunits. Molecular Microbiology 5(7): 1769-1777, 1991

Homologous maturase-like proteins are encoded within the group I introns in different mitochondrial genes specifying Yarrowia lipolytica cytochrome c oxidase subunit 3 and Saccharomyces cerevisiae apocytochrome b. Current Genetics 26(5-6): 377-381, 1994

Is the mitochondrially made subunit 2 of cytochrome oxidase synthesized as a precursor in Neurospora crassa?. Febs Letters 107(2): 327-330, 1979

A pathogenic 15-base pair deletion in mitochondrial DNA-encoded cytochrome c oxidase subunit III results in the absence of functional cytochrome c oxidase. Journal of Biological Chemistry 275(18): 13994-14003, 2000

Study of a point mutation in the mitochondrially-encoded subunit III of cytochrome oxidase affecting the complex assembly in yeast. Biochemical Society Transactions 29(3): A66, 2001

Detection of the mitochondrially encoded cytochrome c oxidase subunit I in the trypanosomatid protozoan Leishmania tarentolae. Evidence for translation of unedited mRNA in the kinetoplast. Journal of Biological Chemistry 275(22): 17160-5, 2000

Deletion of subunit 9 of the Saccharomyces cerevisiae cytochrome bc-1 complex specifically impairs electron transfer at the ubiquinol oxidase site (center P) in the bc-1 complex. FEBS (Federation of European Biochemical Societies) Letters 313(3): 251-254, 1992

Nuclear functions required for cytochrome c oxidase biogenesis in Saccharomyces cerevisiae: multiple trans-acting nuclear genes exert specific effects on expression of each of the cytochrome c oxidase subunits encoded on mitochondrial DNA. Current Genetics 12(5): 311-322, 1987