Yeast TOR signaling: a mechanism for metabolic regulation.
Understanding how cell growth is regulated in response to environmental signals remains a challenging biological problem. Recent studies indicate the TOR (target of rapamycin) kinase acts within an intracellular regulatory network used by eukaryotic cells to regulate their growth according to nutrient availability. This network affects all aspects of gene expression, including transcription, translation, and protein stability, making TOR an excellent candidate as a global regulator of cellular activity. Here we review our recent studies of two specific transcriptional outputs controlled by TOR in the budding yeast, S. cerevisiae: (1) positive regulation of genes involved in ribosome biogenesis, and (2) negative regulation of genes required for de novo biosynthesis of glutamate and glutamine. These studies have raised the important issue as to how diverse nutritional cues can pass through a common signaling pathway and yet ultimately generate distinct transcriptional responses.
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Section of Molecular and Cellular Biology, Center for Genetics and Development, Division of Biological Sciences, University of California Davis, Davis, CA 95616, USA. tpowers@ucdavis.edu
Dilova
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Chen
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Wedaman
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D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; D009584:Nitrogen / Q000378:metabolism; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism / Q000502:physiology*; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000378:metabolism / Q000502:physiology*; D012270:Ribosomes / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000254:growth & development / Q000378:metabolism / Q000502:physiology; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology; D014157:Transcription Factors / Q000502:physiology
D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; D009584:Nitrogen; D019869:Phosphatidylinositol 3-Kinases; D017853:Phosphotransferases (Alcohol Group Acceptor); D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; C079378:RTG1 protein, S cerevisiae; C083324:TOR1 protein, S cerevisiae