title: NPR1 kinase and RSP5-BUL1/2 ubiquitin ligase control GLN3-dependent transcription in Saccharomyces cerevisiae.
abstract: The GATA transcription factors GLN3 and GAT1 activate nitrogen-regulated genes in Saccharomyces cerevisiae. NPR1 is a protein kinase that controls post-Golgi sorting of amino acid permeases. In the presence of a good nitrogen source, TOR (target of rapamycin) maintains GLN3 and NPR1 phosphorylated and inactive by inhibiting the type 2A-related phosphatase SIT4. We identified NPR1 as a regulator of GLN3. Specifically, loss of NPR1 causes nuclear translocation and activation of GLN3, but not GAT1, in nitrogen-rich conditions. NPR1-mediated inhibition of GLN3 is independent of the phosphatase SIT4. We also demonstrate that the E3/E4 ubiquitin-protein ligase proteins RSP5 and BUL1/2 are required for GLN3 activation under poor nitrogen conditions. Thus, NPR1 and BUL1/2 antagonistically control GLN3-dependent transcription, suggesting a role for regulated ubiquitination in the control of nutrient-responsive transcription.
authors.affiliation: Division of Biochemistry, University of Basel, Basel, Switzerland.
authors.forename: José L
authors.initials: JL
authors.lastname: Crespo
authors.forename: Stephen B
authors.initials: SB
authors.lastname: Helliwell
authors.forename: Christa
authors.initials: C
authors.lastname: Wiederkehr
authors.forename: Philippe
authors.initials: P
authors.lastname: Demougin
authors.forename: Brian
authors.initials: B
authors.lastname: Fowler
authors.forename: Michael
authors.initials: M
authors.lastname: Primig
authors.forename: Michael N
authors.initials: MN
authors.lastname: Hall
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000502:physiology*; D056827:Endosomal Sorting Complexes Required for Transport; D009584:Nitrogen / Q000502:physiology; D011392:Proline / Q000378:metabolism; D011494:Protein Kinases / Q000502:physiology*; D012097:Repressor Proteins / Q000235:genetics*; D012441:Saccharomyces cerevisiae / Q000201:enzymology*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics* / Q000502:physiology*; D020123:Sirolimus / Q000494:pharmacology; D014157:Transcription Factors / Q000235:genetics*; D014158:Transcription, Genetic / Q000502:physiology*; D043743:Ubiquitin-Protein Ligase Complexes / Q000502:physiology*; D044767:Ubiquitin-Protein Ligases
chemical_list: D048868:Adaptor Proteins, Signal Transducing; C099939:BUL1 protein, S cerevisiae; C117205:BUL2 protein, S cerevisiae; D056827:Endosomal Sorting Complexes Required for Transport; C071664:GLN3 protein, S cerevisiae; D012097:Repressor Proteins; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; C066958:NPR1 protein, S cerevisiae; D011392:Proline; D043743:Ubiquitin-Protein Ligase Complexes; D044767:Ubiquitin-Protein Ligases; D011494:Protein Kinases; C469287:RSP5 protein, S cerevisiae; D009584:Nitrogen; D020123:Sirolimus