TOR controls translation initiation and early G1 progression in yeast

Barbet, N.C. and Schneider, U. and Helliwell, S.B. and Stansfield, I. and Tuite, M.F. and Hall, M.N. (1996) TOR controls translation initiation and early G1 progression in yeast. Molecular Biology of the Cell, 7 (1). pp. 25-42. ISSN 1059-1524. (The full text of this publication is not available from this repository)

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Abstract

Saccharomyces cerevisiae cells treated with the immunosuppressant rapamycin or depleted for the targets of rapamycin TOR1 and TOR2 arrest growth in the early G1 phase of the cell cycle. Loss of TOR function also causes an early inhibition of translation initiation and induces several other physiological changes characteristic of starved cells entering stationary phase (G0). A G1 cyclin mRNA whose translational control is altered by substitution of the UBI4 5' leader region (UBI4 is normally translated under starvation conditions) suppresses the rapamycin-induced G1 arrest and confers starvation sensitivity. These results suggest that the block in translation initiation is a direct consequence of loss of TOR function and the cause of the G1 arrest. We propose that the TORs, two related phosphatidylinositol kinase homologues, are part of a novel signaling pathway that activates eIF-4E-dependent protein synthesis and, thereby, G1 progression in response to nutrient availability. Such a pathway may constitute a checkpoint that prevents early G1 progression and growth in the absence of nutrients.

Item Type: Article
Additional information: Document Type: Review
Subjects: Q Science > QH Natural history > QH301 Biology
Q Science > QP Physiology (Living systems) > QP506 Molecular biology
Divisions: Faculties > Science Technology and Medical Studies > School of Biosciences
Depositing User: M.A. Ziai
Date Deposited: 16 May 2009 17:47
Last Modified: 16 May 2009 17:47
Resource URI: http://kar.kent.ac.uk/id/eprint/18799 (The current URI for this page, for reference purposes)
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