The WD protein Cpc2p is required for repression of Gcn4 protein activity in yeast in the absence of amino-acid starvation.
The CPC2 gene of the budding yeast Saccharomyces cerevisiae encodes a G beta-like WD protein which is involved in regulating the activity of the general control activator Gcn4p. The CPC2 gene encodes a premRNA which is spliced and constitutively expressed in the presence or absence of amino acids. Loss of CPC2 gene function suppresses a deletion of the GCN2 gene encoding the general control sensor kinase, but not a deletion in the GCN4 gene. The resulting phenotype has resistance against amino-acid analogues. The Neurospora crassa cpc-2 and the rat RACK1 genes are homologues of CPC2 that complement the yeast cpc2 deletion. The cpc2 delta mutation leads to increased transcription of Gcn4p-dependent genes under non-starvation conditions without increasing GCN4 expression or the DNA binding activity of Gcn4p. Cpc2p-mediated transcriptional repression requires the Gcn4p transcriptional activator and a Gcn4p recognition element in the target promoter. Frameshift mutations resulting in a shortened G beta-like protein cause a different phenotype that has sensitivity against amino-acid analogues similar to a gcn2 deletion. Cpc2p seems to be part of an additional control of Gcn4p activity, independent of its translational regulation.
Institute for Microbiology and Genetics, Georg August University, Göttingen, Germany.
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Hoffmann
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HU
Mösch
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Sattlegger
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IB
Barthelmess
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Hinnebusch
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Braus
D000085:Acetates / Q000494:pharmacology; D000199:Actins / Q000235:genetics; D000596:Amino Acids / Q000502:physiology*; D000640:Amitrole / Q000494:pharmacology; D029681:Arabidopsis Proteins; D001483:Base Sequence; D015152:Blotting, Northern; D015153:Blotting, Western; D003574:Cytochrome c Group / Q000235:genetics; D045304:Cytochromes c; D004268:DNA-Binding Proteins; D004843:Epistasis, Genetic; D016368:Frameshift Mutation; D005656:Fungal Proteins / Q000235:genetics* / Q000502:physiology*; D015966:Gene Expression Regulation, Fungal; D005838:Genotype; D005947:Glucose / Q000494:pharmacology; D006128:Growth; D006836:Hydro-Lyases / Q000235:genetics; D007521:Isocitrate Dehydrogenase / Q000032:analysis; D007763:Lac Operon; D008969:Molecular Sequence Data; D009491:Neurospora / Q000235:genetics; D011494:Protein Kinases / Q000235:genetics / Q000502:physiology*; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins; D013997:Time Factors; D001616:beta-Galactosidase / Q000032:analysis
C098619:AAC1 protein, Arabidopsis; D000085:Acetates; D000199:Actins; D000596:Amino Acids; D029681:Arabidopsis Proteins; C095233:CPC-2 protein, Neurospora crassa; C014059:CYC1 protein, S cerevisiae; D003574:Cytochrome c Group; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D029701:Saccharomyces cerevisiae Proteins; D045304:Cytochromes c; D007521:Isocitrate Dehydrogenase; D011494:Protein Kinases; D001616:beta-Galactosidase; D006836:Hydro-Lyases; C021434:imidazoleglycerolphosphate dehydratase; D005947:Glucose; D000640:Amitrole