Cross regulation of four GATA factors that control nitrogen catabolic gene expression in Saccharomyces cerevisiae

Abstract

Nitrogen catabolic gene expression in Saccharomyces cerevisiae has been reported to be regulated by three GATA family proteins, the positive regulators Gln3p and Gat1p/Nil1p and the negative regulator Dal80p/ Uga43p. We show here that a fourth member of the yeast GATA family, the Dal80p homolog Deh1p, also negatively regulates expression of some, but not all, nitrogen catabolic genes, i.e., GAP1, DAL80, and UGA4 expression increases in a deh1⌬ mutant. Consistent with Deh1p regulation of these genes is the observation that Deh1p forms specific DNA-protein complexes with GATAA-containing UGA4 and GAP1 promoter fragments in electrophoretic mobility shift assays. Deh1p function is demonstrable, however, only when a repressive nitrogen source such as glutamine is present; deh1⌬ mutants exhibit no detectable phenotype with a poor nitrogen source such as proline. Our experiments also demonstrate that GATA factor gene expression is highly regulated by the GATA factors themselves in an interdependent manner. DAL80 expression is Gln3p and Gat1p dependent and Dal80p regulated. Moreover, Gln3p and Dal80p bind to DAL80 promoter fragments. In turn, GAT1 expression is Gln3p dependent and Dal80p regulated but is not autogenously regulated like DAL80. DEH1 expression is largely Gln3p independent, modestly Gat1p dependent, and most highly regulated by Dal80p. Paradoxically, the high-level DEH1 expression observed in a dal80::hisG disruption mutant is highly sensitive to nitrogen catabolite repression.

Saccharomyces cerevisiae GATA Sequences Function as TATA Elements during Nitrogen Catabolite Repression and When Gln3p Is Excluded from the Nucleus by Overproduction of Ure2p

“…In other words, the lower species is regulated like any well studied NCR-sensitive gene, e.g. DAL5 or DAL80 (5,20). The upper species, in contrast, is expressed only in a gln3⌬ or when cells are grown under repressive conditions (with glutamine) (Fig.…”

Life in the midst of scarcity: adaptations to nutrient availability in Saccharomyces cerevisiae

“…This pathway ensures that genes encoding proteins required for the usage of poor nitrogen sources are repressed when rich nitrogen sources, such as glutamine, are present in sufficient quantities. Four GATA family zinc-finger transcription factors are involved in the transcriptional control exerted by the NDP: two activators, Gln3 and Gat1, and two repressors, Dal80 and Gzf3 (Minehart and Magasanik 1991;Coffman et al 1995Coffman et al , 1996Coffman et al , 1997Cooper 2002). TORC1 inhibits transcription of NDP genes by controlling Gln3 and Gat1 function (Beck et al 1999;Cardenas et al 1999;Hardwick et al 1999;Shamji et al 2000).…”

Constitutive and Nitrogen Catabolite Repression-sensitive Production of Gat1 Isoforms

“…NCR-sensitive, GATA factorregulated transcription of GAT1 also correlated with the presence of six cis-acting UAS GATA elements, the core of which was GATAAG, in its promoter (16). Finally, Gln3, Dal80, Gzf3/ Deh1, and Gat1 bind in vitro and in vivo to the GAT1 promoter and specifically to the UAS GATA elements of multiple NCRsensitive genes (17,(22)(23)(24). In other words, GAT1 expression exhibited all of the characteristics of a typical NCR-sensitive gene.…”