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.
Robaglia
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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
Menand
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B
Lei
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Y
Sormani
R
R
Nicolaï
M
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Gery
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C
Teoulé
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Deprost
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Meyer
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D018506:Gene Expression Regulation, Plant; D063245:Plant Development; D010944:Plants / Q000235:genetics; D014176:Protein Biosynthesis; D012323:RNA Processing, Post-Transcriptional