Chloroplast RNA Editing Required for Functional Acetyl-CoA Carboxylase in Plants

Sasaki, Yukiko; Kozaki, Akiko; Ohmori, Akira; Iguchi, Hiro; Nagano, Yukio

doi:10.1074/jbc.m008166200

Cited by 74 publications

(66 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Few mRNAs in plastids do not contain either start or stop codons; therefore, C-to-U editing enables the expression of functional proteins by generating start or stop codons and modifying amino acid sequences (34)(35)(36). In plastids, C-to-U RNA editing occurs in mRNAs but not in other RNA types, including transfer RNA (tRNA) and ribosome RNA (rRNA).…”

Section: C-to-u Rna Editing In Mammalsmentioning

confidence: 99%

C-to-U editing and site-directed RNA editing for the correction of genetic mutations

Tsukahara

2017

BST

View full text Add to dashboard Cite

Section: C-to-u Rna Editing In Mammalsmentioning

confidence: 99%

C-to-U editing and site-directed RNA editing for the correction of genetic mutations

Tsukahara

2017

BST

View full text Add to dashboard Cite

“…Most editing events occur in protein-coding regions and restore codons to conserved amino acids. In chloroplasts, editing of psbF, petB, and accD mRNAs has been reported to be necessary for the function of their products (8)(9)(10), indicating that at least some RNA editing events are essential posttranscriptional steps. However, one RNA editing event was observed in the third position of a codon and did not lead to amino acid substitution (11).…”

mentioning

confidence: 99%

A site-specific factor interacts directly with its cognate RNA editing site in chloroplast transcripts

Miyamoto

Obokata

Sugiura

2003

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

RNA editing involves a variety of genetic systems and occurs by different mechanisms. In higher plant chloroplasts, specific sites of some transcripts are subject to C-to-U conversion. We have previously shown that site-specific trans-acting factors for psbE and petB mRNA editing bind corresponding cis-elements, which are located 5 nucleotides upstream from the editing site. Here we report that, by using mRNAs labeled either at the center of the upstream cis-element or at the editing site, the site-specific factors can be cross-linked with nucleotides at both positions. Mutations of nucleotides in the proximal region of the editing site revealed a correlation between editing activity and cross-linking efficiency of factors with the editing site, even though cross-linking with the upstream cis-element was unaffected. These observations suggest that the site-specific factor binds stably to the upstream ciselement, whereas it interacts weakly with the editing site. This finding raises the intriguing possibility that the site-specific factor is involved in both site-determination and C-to-U conversion in chloroplast RNA editing. R NA editing is one of the posttranscriptional processes involved in transcript maturation in a variety of organisms, including viruses, fungi, plants, and mammals (1). This process can be subdivided into insertion͞deletion of nucleotides and base modification. RNA editing in plant organelles belongs to the latter case; specific sites of some transcripts are subject to C-to-U (and rarely U-to-C) conversions (2-7). Most editing events occur in protein-coding regions and restore codons to conserved amino acids. In chloroplasts, editing of psbF, petB, and accD mRNAs has been reported to be necessary for the function of their products (8-10), indicating that at least some RNA editing events are essential posttranscriptional steps. However, one RNA editing event was observed in the third position of a codon and did not lead to amino acid substitution (11). Hence, at least one case of editing seems to have no biological significance.At present, 34 C-to-U editing sites have been found in tobacco chloroplast transcripts (12). Cis-analysis has been pursued for several sites by transplastomic approaches, and all defined cis-acting elements are located within Ϸ30 nucleotides of editing sites (13-15). Sequences surrounding editing sites exhibit no common characteristics, except most of the 5Ј neighboring residues of editing sites are pyrimidines and the 3Ј neighbors are A residues, both in chloroplast and mitochondrial transcripts (16,17). The importance of 5Ј neighbors for editing efficiency has been reported in psbL and ndhB mRNA (site V) editing (13,14).We have recently studied the mechanism of psbE and petB mRNA editing in tobacco and pea chloroplasts (18). Both chloroplast genes possess single editing sites that depend on plant species. The 72nd codon of psbE is encoded as Ser (UCU) at the DNA level in spinach, pea, and maize, whereas tobacco, Arabidopsis, and black pine restore this codon from Pro...

show abstract

“…Previous studies on ACCase in plants addressed such questions as tissue-specific expression (Hawke and Leech, 1987;Bao et al, 1997;Ke et al, 1997;Caffrey et al, 1998;Thelen et al, 2001;O'Hara et al, 2002), the role of phosphorylation (Savage and Ohlrogge, 1999), light and redox status of the enzyme (Sasaki et al, 1997;Kozaki et al, 2000), mRNA editing (Sasaki et al, 2001), and protein biotinylation (Alban et al, 2000). Possible sources of acetyl-CoA for plastid and cytosolic ACCase and related problems of carbon partitioning in plastid metabolism have been investigated Eastmond and Rawsthorne, 2000;Ke et al, 2000;Ohlrogge et al, 2000;Rawsthorne, 2002).…”

mentioning

confidence: 99%

Expression of Cytosolic and Plastid Acetyl-Coenzyme A Carboxylase Genes in Young Wheat Plants,

et al. 2003

View full text Add to dashboard Cite

Expression of cytosolic and plastid acetyl-coenzyme A carboxylase (ACCase) gene families at the mRNA level was analyzed in developing wheat (Triticum aestivum) plants. The major plastid ACCase mRNA level is high in the middle part of the plant and low in roots and leaf blades. An alternative plastid ACCase transcript initiated at a different promoter and using an alternative 5Ј splice site for the first intron accumulates to its highest level in roots. Cytosolic ACCase mRNA also consists of two species, one of which is present at approximately a constant level, whereas the other accumulates to a high level in the lower sheath section. It is likely that different promoters are also responsible for the two forms of cytosolic ACCase mRNA. The abundances of cytosolic and plastid ACCase mRNAs in the sheath section of the plant are similar. ACCase protein level is significantly lower in the leaf blades, in parallel with changes in the total ACCase mRNA level. Homoeologous ACCase genes show the same expression patterns and similar mRNA levels, suggesting that none of the genes was silenced or acquired new tissue specificity after polyploidization.Acetyl-CoA carboxylase (ACCase) directs the flow of carbon from photosynthesis to primary and secondary metabolites in plants. One ACCase isozyme supplies malonyl-CoA for de novo fatty acid biosynthesis in plastids. A second ACCase isozyme supplies malonyl-CoA for fatty acid elongation and flavonoid biosynthesis in the cytosol. Their activity is expected to be fine tuned, responding to the demand for specific metabolites determined by plant development and by the environment. Our study focused on correlations between major developmental processes in the young wheat (Triticum aestivum) plant and expression of the ACCase gene families. The wheat leaf provides a succession of cells of different age and characteristics, from dividing cells of the leaf meristem located at the leaf base, to cells undergoing rapid enlargement accompanied by chloroplast maturation, to fully photosynthetically active cells in the leaf blade. These cells can be contrasted with photosynthetically inactive cells in the roots.ACCase and its product, malonyl-CoA, play a key role in regulating metabolite flux through the fatty acid biosynthetic and degradative pathways, and are important regulators of carbon allocation and energy homeostasis. In mammals, ACCase is regulated by multiple mechanisms including tissue-specific promoters, reversible phosphorylation, and feedback by a number of metabolites (Kim, 1997;Munday and Hemingway, 2001). In Escherichia coli, transcription of ACCase genes is correlated with the rate of cellular growth, overexpression of all four subunits of ACCase increasing the rate of fatty acid biosynthesis (Davis et al., 2000). The expression of the ACCase gene in yeast (Saccharomyces cerevisiae) is coordinated with phospholipid metabolism (Haslacher et al., 1993). For plants, it has been suggested that plastid ACCase activity controls flux through the de novo fatty acid biosynthetic pat...

show abstract

Chloroplast RNA Editing Required for Functional Acetyl-CoA Carboxylase in Plants

Cited by 74 publications

References 32 publications

C-to-U editing and site-directed RNA editing for the correction of genetic mutations

C-to-U editing and site-directed RNA editing for the correction of genetic mutations

A site-specific factor interacts directly with its cognate RNA editing site in chloroplast transcripts

Expression of Cytosolic and Plastid Acetyl-Coenzyme A Carboxylase Genes in Young Wheat Plants,

Contact Info

Product

Resources

About