Translational control of GCN4: an in vivo barometer of initiation-factor activity.
Phosphorylation of translation initiation factor-2 (eIF-2) is an adaptive mechanism for downregulating protein synthesis under conditions of starvation and stress. The yeast Saccharomyces has evolved a sophisticated means of increasing translation of GCN4 mRNA when eIF-2 is phosphorylated, allowing the induction of an important stress-response protein when expression of most other genes is decreasing. Because translation of GCN4 mRNA is so tightly coupled to eIF-2 activity, genetic analysis of this system has provided unexpected insights into the regulation of eIF-2 and its guanine nucleotide exchange factor, eIF-2B.
Hinnebusch
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Section on Molecular Genetics of Lower Eukaryotes, National Institute of Child Health and Human Development, Bethesda, MD 20892.
D000596:Amino Acids / Q000008:administration & dosage; D004268:DNA-Binding Proteins; D015852:Eukaryotic Initiation Factor-2 / Q000378:metabolism; D005656:Fungal Proteins / Q000235:genetics*; D015966:Gene Expression Regulation, Fungal; D010766:Phosphorylation; D014176:Protein Biosynthesis; D011494:Protein Kinases / Q000235:genetics*; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000502:physiology; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors / Q000235:genetics*
D000596:Amino Acids; D004268:DNA-Binding Proteins; D015852:Eukaryotic Initiation Factor-2; D005656:Fungal Proteins; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D011494:Protein Kinases