Nucleotide sequence of the cytochrome oxidase subunit 2 and <i>val</i>‐tRNA genes and surrounding sequences from <i>Kluyveromyces lactis</i> K8 mitochondrial DNA

Hardy, Christopher M.; Clark-Walker, G. D.

doi:10.1002/yea.320060505

Cited by 24 publications

(12 citation statements)

References 47 publications

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“…Thus the prospects for defining an activator target appear best here. Indeed, Clark-Walker and coworkers have identified a short conserved sequence in the COX2 5'-UTLs of several budding yeasts [40,41]. Mutational analysis of the S. cerevisiae COX2 5'-UTL in this lab has defined a 31 base region required for translation, that includes this conserved sequence in a stem structure (H. M. Dunstan and T. D. Fox, unpublished observation).…”

Section: Mrna-specific Translational Activators Recognize Sites In Thmentioning

confidence: 90%

Translational control of endogenous and recoded nuclear genes in yeast mitochondria: Regulation and membrane targeting

Fox

1996

Experientia

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Mitochondrial gene expression in yeast, Saccharomyces cerevisiae, depends on translational activation of individual mRNAs by distinct proteins encoded in the nucleus. These unclearly coded mRNA-specific translational activators are bound to the inner membrane and function to mediate the interaction between mRNAs and mitochondrial ribosomes. This complex system, found to date only in organelles, appears to be an adaptation for targeting the synthesis of mitochondrially coded integral membrane proteins to the membrane. In addition, mRNA-specific translational activation is a rate-limiting step used to modulate expression of at least one mitochondrial gene in response to environmental conditions. Direct study of mitochondrial gene regulation and the targeting of mitochondrially coded proteins in vivo will now be possible using synthetic genes inserted into mtDNA that encode soluble reporter/passenger proteins.

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Section: Mrna-specific Translational Activators Recognize Sites In Thmentioning

confidence: 90%

Translational control of endogenous and recoded nuclear genes in yeast mitochondria: Regulation and membrane targeting

Fox

1996

Experientia

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“…The leader peptide sequences from several fungal and plant species are not strongly conserved (20,25), and animal forms of Cox2p lack it entirely. While a previous study indicated that the leader peptide causes membrane association of a passenger protein (21), our present findings demonstrate that several amino acid sequences, which were generated by frameshifts and various peptide lengths, can effectively carry out this and/or any other steps necessary for cytochrome oxidase assembly.…”

Section: Discussionmentioning

confidence: 99%

“…While the leader peptide causes membrane association of a soluble passenger protein fused to it, it does not function as a classical signal sequence since it is incapable of directing translocation of the passenger protein through the inner membrane (21). Nucleic acid sequence comparisons indicate that the pre-Cox2p leader peptides of various budding yeast species, including Neurospora crassa, and plants are not highly conserved (20,25). Mammalian Cox2p entirely lacks a leader peptide (3,50).…”

mentioning

confidence: 99%

Mitochondrial Translation of Saccharomyces cerevisiae COX2 mRNA Is Controlled by the Nucleotide Sequence Specifying the Pre-Cox2p Leader Peptide

Bonnefoy

Bsat

Fox

2001

Molecular and Cellular Biology

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The mitochondrial gene encoding yeast cytochrome oxidase subunit II (Cox2p) specifies a precursor protein with a 15-amino-acid leader peptide. Deletion of the entire leader peptide coding region is known to block Cox2p accumulation posttranscriptionally. Here, we examined in vivo the role of the pre-Cox2p leader peptide and the mRNA sequence that encodes it in the expression of a mitochondrial reporter gene, ARG8 m , fused to the 91st codon of COX2. We found within the coding sequence antagonistic elements that control translation: the positive element includes sequences in the first 14 codons specifying the leader peptide, while the negative element appears to be within codons 15 to 91. Partial deletions, point mutations, and local frameshifts within the leader peptide coding region were placed in both the cox2::ARG8 m reporter and in COX2 itself. Surprisingly, the mRNA sequence of the first six codons specifying the leader peptide plays an important role in positively controlling translation, while the amino acid sequence of the leader peptide itself is relatively unconstrained. Two mutations that partially block translation can be suppressed by nearby sequence substitutions that weaken a predicted stem structure and by overproduction of either the COX2 mRNA-specific translational activator Pet111p or the large-subunit mitochondrial ribosomal protein MrpL36p. We propose that regulatory elements embedded in the translated COX2 mRNA sequence could play a role, together with trans-acting factors, in coupling regulated synthesis of nascent pre-Cox2p to its insertion in the mitochondrial inner membrane.

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“…Further, the leader peptide is essential for accumulation of functional Cox2p, as deletion of the leader peptide coding sequence inhibits respiration (Torello et al 1997). Interestingly, however, mammalian Cox2p is synthesized without a leader peptide (Steffens and Buse 1979;Anderson et al 1982), and the leader peptide sequences of pre-Cox2p or other mitochondrial precursor proteins in other fungi (Hardy and Clark-Walker 1990;Hoeben et al 1993) and in plants (Lu and Hanson 1994) show little similarity to each other.…”

Section: Introductionmentioning

confidence: 99%

Antagonistic signals within the COX2 mRNA coding sequence control its translation in Saccharomyces cerevisiae mitochondria

Williams¹,

Fox²

2003

RNA

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Translation of the mitochondrially coded COX2 mRNA within the organelle in yeast produces the precursor of Cox2p (preCox2p), which is processed and assembled into cytochrome c oxidase. The mRNA sequence of the first 14 COX2 codons, specifying the pre-Cox2p leader peptide, was previously shown to contain a positively acting element required for translation of a mitochondrial reporter gene, ARG8 m , fused to the 91st codon of COX2. Here we show that three relatively short sequences within the COX2 mRNA coding sequence, or structures they form in vivo, inhibit translation of the reporter in the absence of the positive element. One negative element was localized within codons 15 to 25 and shown to function at the level of the mRNA sequence, whereas two others are within predicted stem-loop structures formed by codons 22-44 and by codons 46-74. All three of these inhibitory elements are antagonized in a sequence-specific manner by reintroduction of the upstream positive-acting sequence. These interactions appear to be independent of 5-and 3-untranslated leader sequences, as they are also observed when the same reporter constructs are expressed from the COX3 locus. Overexpression of MRS2, which encodes a mitochondrial magnesium carrier, partially suppresses translational inhibition by each isolated negatively acting element, but does not suppress them in combination. We hypothesize that interplay among these signals during translation in vivo may ensure proper timing of pre-Cox2p synthesis and assembly into cytochrome c oxidase.

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Nucleotide sequence of the cytochrome oxidase subunit 2 and val‐tRNA genes and surrounding sequences from Kluyveromyces lactis K8 mitochondrial DNA

Cited by 24 publications

References 47 publications

Translational control of endogenous and recoded nuclear genes in yeast mitochondria: Regulation and membrane targeting

Translational control of endogenous and recoded nuclear genes in yeast mitochondria: Regulation and membrane targeting

Mitochondrial Translation of Saccharomyces cerevisiae COX2 mRNA Is Controlled by the Nucleotide Sequence Specifying the Pre-Cox2p Leader Peptide

Antagonistic signals within the COX2 mRNA coding sequence control its translation in Saccharomyces cerevisiae mitochondria

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