Plant growth: the translational connection.
The TOR (target of rapamycin) pathway is a phylogenetically conserved transduction system in eukaryotes linking the energy status of the cell to the protein synthesis apparatus and to cell growth. The TOR protein is specifically inhibited by a rapamycin-FKBP12 complex (where FKBP stands for FK506-binding protein) in yeast and animal cells. Whereas plants appear insensitive to rapamycin, Arabidopsis thaliana harbours a single TOR gene, which is essential for embryonic development. It was found that the product of this gene was capable of binding to rapamycin and yeast FKBP12. In-frame fusion with a GUS reporter gene shows that the TOR protein is produced essentially in proliferating zones, whereas the TOR mRNA can be detected in all organs suggesting a translational regulation of TOR. Phenotypic analysis of Arabidopsis TOR mutants indicates that the plant TOR pathway fulfils the same role in controlling cell growth as its other eukaryotic counterparts.
Laboratoire de Génétique et Biophysique des Plantes, Département d'Ecophysiologie Végétale et Microbiologie, UMR 6191 CNRS-CEA-Université de la Méditerranée, Luminy, Marseille, France. ROBAGLIA@dsvsud.cea.fr
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Menand
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Lei
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Sormani
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Nicolaï
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Gery
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Teoulé
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Deprost
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Meyer
D018506:Gene Expression Regulation, Plant; D063245:Plant Development; D010944:Plants / Q000235:genetics; D014176:Protein Biosynthesis; D012323:RNA Processing, Post-Transcriptional