Translational regulation of Arabidopsis XIPOTL1 is modulated by phosphocholine levels via the phylogenetically conserved upstream open reading frame 30
In Arabidopsis thaliana, XIPOTL1 encodes a phosphoethanolamine N-methyltransferase with a central role in phosphatidylcholine biosynthesis via the methylation pathway. To gain further insights into the mechanisms that regulate XIPOTL1 expression, the effect of upstream open reading frame 30 (uORF30)...
| Veröffentlicht in: | Journal of experimental botany. - 1985. - 63(2012), 14 vom: 12. Sept., Seite 5203-21 |
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| 1. Verfasser: | |
| Weitere Verfasser: | , , , , , , , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2012
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| Zugriff auf das übergeordnete Werk: | Journal of experimental botany |
| Schlagworte: | Journal Article Research Support, Non-U.S. Gov't Arabidopsis Proteins DNA, Plant Phosphorylcholine 107-73-3 Methyltransferases EC 2.1.1.- phosphoethanolamine methyltransferase Choline |
| Zusammenfassung: | In Arabidopsis thaliana, XIPOTL1 encodes a phosphoethanolamine N-methyltransferase with a central role in phosphatidylcholine biosynthesis via the methylation pathway. To gain further insights into the mechanisms that regulate XIPOTL1 expression, the effect of upstream open reading frame 30 (uORF30) on the translation of the major ORF (mORF) in the presence or absence of endogenous choline (Cho) or phosphocholine (PCho) was analysed in Arabidopsis seedlings. Dose-response assays with Cho or PCho revealed that both metabolites at physiological concentrations are able to induce the translational repression of a mORF located downstream of the intact uORF30, without significantly altering its mRNA levels. PCho profiles showed a correlation between increased endogenous PCho levels and translation efficiency of a uORF30-containing mORF, while no correlation was detectable with Cho levels. Enhanced expression of a uORF30-containing mORF and decreased PCho levels were observed in the xipotl1 mutant background relative to wild type, suggesting that PCho is the true mediator of uORF30-driven translational repression. In Arabidopsis, endogenous PCho content increases during plant development and affects root meristem size, cell division, and cell elongation. Because XIPOTL1 is preferentially expressed in Arabidopsis root tips, higher PCho levels are found in roots than shoots, and there is a higher sensitivity of this tissue to translational uORF30-mediated control, it is proposed that root tips are the main site for PCho biosynthesis in Arabidopsis |
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| Beschreibung: | Date Completed 24.01.2013 Date Revised 21.11.2013 published: Print-Electronic Citation Status MEDLINE |
| ISSN: | 1460-2431 |
| DOI: | 10.1093/jxb/ers180 |