1932

Abstract

Abstract

Cells reprogram gene expression in response to environmental changes by mobilizing transcriptional activators. The activator protein Gcn4 of the yeast is regulated by an intricate translational control mechanism, which is the primary focus of this review, and also by the modulation of its stability in response to nutrient availability. Translation of mRNA is derepressed in amino acid-deprived cells, leading to transcriptional induction of nearly all genes encoding amino acid biosynthetic enzymes. The -acting proteins that control translation have general functions in the initiation of protein synthesis, or regulate the activities of initiation factors, so that the molecular events that induce translation also reduce the rate of general protein synthesis. This dual regulatory response enables cells to limit their consumption of amino acids while diverting resources into amino acid biosynthesis in nutrient-poor environments. Remarkably, mammalian cells use the same strategy to downregulate protein synthesis while inducing transcriptional activators of stress-response genes under various stressful conditions, including amino acid starvation.

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/content/journals/10.1146/annurev.micro.59.031805.133833
2005-10-13
2024-06-24
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  • Article Type: Review Article
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