title: General Amino Acid Control and 14-3-3 Proteins Bmh1/2 Are Required for Nitrogen Catabolite Repression-Sensitive Regulation of Gln3 and Gat1 Localization.
abstract: Nitrogen catabolite repression (NCR), the ability of Saccharomyces cerevisiae to use good nitrogen sources in preference to poor ones, derives from nitrogen-responsive regulation of the GATA family transcription activators Gln3 and Gat1 In nitrogen-replete conditions, the GATA factors are cytoplasmic and NCR-sensitive transcription minimal. When only poor nitrogen sources are available, Gln3 is nuclear, dramatically increasing GATA factor-mediated transcription. This regulation was originally attributed to mechanistic Tor protein kinase complex 1 (mTorC1)-mediated control of Gln3 However, we recently showed that two regulatory systems act cumulatively to maintain cytoplasmic Gln3 sequestration, only one of which is mTorC1. Present experiments demonstrate that the other previously elusive component is uncharged transfer RNA-activated, Gcn2 protein kinase-mediated general amino acid control (GAAC). Gcn2 and Gcn4 are required for NCR-sensitive nuclear Gln3-Myc13localization, and from epistasis experiments Gcn2 appears to function upstream of Ure2 Bmh1/2 are also required for nuclear Gln3-Myc13localization and appear to function downstream of Ure2 Overall, Gln3 phosphorylation levels decrease upon loss of Gcn2, Gcn4, or Bmh1/2 Our results add a new dimension to nitrogen-responsive GATA-factor regulation and demonstrate the cumulative participation of the mTorC1 and GAAC pathways, which respond oppositely to nitrogen availability, in the nitrogen-responsive control of catabolic gene expression in yeast.
authors.affiliation: Department of Microbiology, Immunology, and Biochemistry, University of Tennessee Health Science Center, Memphis, Tennessee 38163.
authors.forename: Jennifer J
authors.initials: JJ
authors.lastname: Tate
authors.affiliation: Department of Microbiology, Immunology, and Biochemistry, University of Tennessee Health Science Center, Memphis, Tennessee 38163.
authors.forename: David
authors.initials: D
authors.lastname: Buford
authors.affiliation: Department of Microbiology, Immunology, and Biochemistry, University of Tennessee Health Science Center, Memphis, Tennessee 38163.
authors.forename: Rajendra
authors.initials: R
authors.lastname: Rai
authors.affiliation: Department of Microbiology, Immunology, and Biochemistry, University of Tennessee Health Science Center, Memphis, Tennessee 38163 tcooper@uthsc.edu.
authors.forename: Terrance G
authors.initials: TG
authors.lastname: Cooper
mesh_terms: D048948:14-3-3 Proteins / Q000235:genetics / Q000378:metabolism*; D021581:Active Transport, Cell Nucleus; D000596:Amino Acids / Q000378:metabolism; D050976:Basic-Leucine Zipper Transcription Factors / Q000235:genetics / Q000378:metabolism*; D057465:Catabolite Repression; D002467:Cell Nucleus / Q000378:metabolism*; D004843:Epistasis, Genetic; D050980:GATA Transcription Factors / Q000235:genetics / Q000378:metabolism*; D005979:Glutathione Peroxidase / Q000235:genetics / Q000378:metabolism; D000076222:Mechanistic Target of Rapamycin Complex 1; D046912:Multiprotein Complexes / Q000235:genetics / Q000378:metabolism; D009584:Nitrogen / Q000378:metabolism; D010766:Phosphorylation; D011328:Prions / Q000235:genetics / Q000378:metabolism; D011499:Protein Processing, Post-Translational; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D058570:TOR Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D048948:14-3-3 Proteins; D000596:Amino Acids; D050976:Basic-Leucine Zipper Transcription Factors; C096100:GAT1 protein, S cerevisiae; D050980:GATA Transcription Factors; C501391:GCN4 protein, S cerevisiae; C071664:GLN3 protein, S cerevisiae; D046912:Multiprotein Complexes; D011328:Prions; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D005979:Glutathione Peroxidase; C067020:URE2 protein, S cerevisiae; C512912:GCN2 protein, S cerevisiae; D000076222:Mechanistic Target of Rapamycin Complex 1; D017346:Protein Serine-Threonine Kinases; D058570:TOR Serine-Threonine Kinases; D009584:Nitrogen
keywords: Bmh1/2; Gat1; Gcn2; Gln3; nitrogen catabolite repression