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The RNA editing pattern of cox2 mRNA is affected by point mutations in plant mitochondria.

Castandet B, Araya A - PLoS ONE (2011)

Bottom Line: It has been reported that a short region surrounding the target C forms the cis-recognition elements, but individual residues on it do not play similar roles for the different editing sites.We found that four different recognition patterns can be distinguished: (a) +1 dependency, (b) -1 dependency, (c) +1/-1 dependency, and (d) no dependency on nearest neighbor residues.Our data suggest that the complex response observed for cox2 mRNA may be a consequence of the fate of the transcript during mitochondrial gene expression.

View Article: PubMed Central - PubMed

Affiliation: Laboratoire de Microbiologie Cellulaire et Moléculaire et Pathogénicité, MCMP- UMR5234, Centre National de la Recherche Scientifique and Université Bordeaux Segalen. Bordeaux, France.

ABSTRACT
The mitochondrial transcriptome from land plants undergoes hundreds of specific C-to-U changes by RNA editing. These events are important since most of them occur in the coding region of mRNAs. One challenging question is to understand the mechanism of recognition of a selected C residue (editing sites) on the transcript. It has been reported that a short region surrounding the target C forms the cis-recognition elements, but individual residues on it do not play similar roles for the different editing sites. Here, we studied the role of the -1 and +1 nucleotide in wheat cox2 editing site recognition using an in organello approach. We found that four different recognition patterns can be distinguished: (a) +1 dependency, (b) -1 dependency, (c) +1/-1 dependency, and (d) no dependency on nearest neighbor residues. A striking observation was that whereas a 23 nt cis region is necessary for editing, some mutants affect the editing efficiency of unmodified distant sites. As a rule, mutations or pre-edited variants of the transcript have an impact on the complete set of editing targets. When some Cs were changed into Us, the remaining editing sites presented a higher efficiency of C-to-U conversion than in wild type mRNA. Our data suggest that the complex response observed for cox2 mRNA may be a consequence of the fate of the transcript during mitochondrial gene expression.

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Editing of cox2 transcripts carrying pre-edited sites.Residues C259, C466, C467, C550 and C704 were changed into T (pre-edited) on the cox2 transgene. The editing efficiency of the remaining sites was determined by sequencing at least 16 independent RT-PCR clones obtained from spliced products. Gray bars represent the values obtained from wild type transcripts. Blue bars indicate the values from mutated mRNAs. Pre-edited sites are depicted by light gray bars. The results presented are representative from at least two separate experiments. Editing efficiency variations in replicates was lower than 10%.
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pone-0020867-g003: Editing of cox2 transcripts carrying pre-edited sites.Residues C259, C466, C467, C550 and C704 were changed into T (pre-edited) on the cox2 transgene. The editing efficiency of the remaining sites was determined by sequencing at least 16 independent RT-PCR clones obtained from spliced products. Gray bars represent the values obtained from wild type transcripts. Blue bars indicate the values from mutated mRNAs. Pre-edited sites are depicted by light gray bars. The results presented are representative from at least two separate experiments. Editing efficiency variations in replicates was lower than 10%.

Mentions: To verify whether the editing status of one site may have an impact on the editing efficiency of others, we decided to modify the residues that are highly edited in wild type transcripts. For this purpose, sites C259, C466, C467, C550 and C704 were mutated into Ts (pre-edited state). Notably, sites C77, C167, C169, C482, C638 and C682 were more efficiently edited in pre-edited than in wild type mRNAs. The editing efficiency of sites C30, C385, C449, C563 and C620 showed minor differences or none at all. Interestingly, site C587 behaves differently as it was less edited in the pre-edited context than in the wild type one (Fig. 3).


The RNA editing pattern of cox2 mRNA is affected by point mutations in plant mitochondria.

Castandet B, Araya A - PLoS ONE (2011)

Editing of cox2 transcripts carrying pre-edited sites.Residues C259, C466, C467, C550 and C704 were changed into T (pre-edited) on the cox2 transgene. The editing efficiency of the remaining sites was determined by sequencing at least 16 independent RT-PCR clones obtained from spliced products. Gray bars represent the values obtained from wild type transcripts. Blue bars indicate the values from mutated mRNAs. Pre-edited sites are depicted by light gray bars. The results presented are representative from at least two separate experiments. Editing efficiency variations in replicates was lower than 10%.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3113845&req=5

pone-0020867-g003: Editing of cox2 transcripts carrying pre-edited sites.Residues C259, C466, C467, C550 and C704 were changed into T (pre-edited) on the cox2 transgene. The editing efficiency of the remaining sites was determined by sequencing at least 16 independent RT-PCR clones obtained from spliced products. Gray bars represent the values obtained from wild type transcripts. Blue bars indicate the values from mutated mRNAs. Pre-edited sites are depicted by light gray bars. The results presented are representative from at least two separate experiments. Editing efficiency variations in replicates was lower than 10%.
Mentions: To verify whether the editing status of one site may have an impact on the editing efficiency of others, we decided to modify the residues that are highly edited in wild type transcripts. For this purpose, sites C259, C466, C467, C550 and C704 were mutated into Ts (pre-edited state). Notably, sites C77, C167, C169, C482, C638 and C682 were more efficiently edited in pre-edited than in wild type mRNAs. The editing efficiency of sites C30, C385, C449, C563 and C620 showed minor differences or none at all. Interestingly, site C587 behaves differently as it was less edited in the pre-edited context than in the wild type one (Fig. 3).

Bottom Line: It has been reported that a short region surrounding the target C forms the cis-recognition elements, but individual residues on it do not play similar roles for the different editing sites.We found that four different recognition patterns can be distinguished: (a) +1 dependency, (b) -1 dependency, (c) +1/-1 dependency, and (d) no dependency on nearest neighbor residues.Our data suggest that the complex response observed for cox2 mRNA may be a consequence of the fate of the transcript during mitochondrial gene expression.

View Article: PubMed Central - PubMed

Affiliation: Laboratoire de Microbiologie Cellulaire et Moléculaire et Pathogénicité, MCMP- UMR5234, Centre National de la Recherche Scientifique and Université Bordeaux Segalen. Bordeaux, France.

ABSTRACT
The mitochondrial transcriptome from land plants undergoes hundreds of specific C-to-U changes by RNA editing. These events are important since most of them occur in the coding region of mRNAs. One challenging question is to understand the mechanism of recognition of a selected C residue (editing sites) on the transcript. It has been reported that a short region surrounding the target C forms the cis-recognition elements, but individual residues on it do not play similar roles for the different editing sites. Here, we studied the role of the -1 and +1 nucleotide in wheat cox2 editing site recognition using an in organello approach. We found that four different recognition patterns can be distinguished: (a) +1 dependency, (b) -1 dependency, (c) +1/-1 dependency, and (d) no dependency on nearest neighbor residues. A striking observation was that whereas a 23 nt cis region is necessary for editing, some mutants affect the editing efficiency of unmodified distant sites. As a rule, mutations or pre-edited variants of the transcript have an impact on the complete set of editing targets. When some Cs were changed into Us, the remaining editing sites presented a higher efficiency of C-to-U conversion than in wild type mRNA. Our data suggest that the complex response observed for cox2 mRNA may be a consequence of the fate of the transcript during mitochondrial gene expression.

Show MeSH