title: Premature termination of GAT1 transcription explains paradoxical negative correlation between nitrogen-responsive mRNA, but constitutive low-level protein production.
abstract: The first step in executing the genetic program of a cell is production of mRNA. In yeast, almost every gene is transcribed as multiple distinct isoforms, differing at their 5' and/or 3' termini. However, the implications and functional significance of the transcriptome-wide diversity of mRNA termini remains largely unexplored. In this paper, we show that the GAT1 gene, encoding a transcriptional activator of nitrogen-responsive catabolic genes, produces a variety of mRNAs differing in their 5' and 3' termini. Alternative transcription initiation leads to the constitutive, low level production of 2 full length proteins differing in their N-termini, whereas premature transcriptional termination generates a short, highly nitrogen catabolite repression- (NCR-) sensitive transcript that, as far as we can determine, is not translated under the growth conditions we used, but rather likely protects the cell from excess Gat1.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Georis
authors.affiliation: a Yeast Physiology ; Institut de Recherches Microbiologiques J. M. Wiame ; Laboratoire de Microbiologie Université Libre de Bruxelles ; Brussels , Belgium.
authors.forename: Georis
authors.initials: G
authors.lastname: Isabelle
authors.forename: Jennifer J
authors.initials: JJ
authors.lastname: Tate
authors.forename: Fabienne
authors.initials: F
authors.lastname: Vierendeels
authors.forename: Terrance G
authors.initials: TG
authors.lastname: Cooper
authors.forename: Evelyne
authors.initials: E
authors.lastname: Dubois
mesh_terms: D020413:3' Untranslated Regions / Q000235:genetics; D020121:5' Untranslated Regions / Q000235:genetics; D017398:Alternative Splicing; D000595:Amino Acid Sequence; D001483:Base Sequence; D015152:Blotting, Northern; D015153:Blotting, Western; D050980:GATA Transcription Factors / Q000235:genetics* / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal; D008957:Models, Genetic; D008969:Molecular Sequence Data; D009584:Nitrogen / Q000378:metabolism*; D010802:Phylogeny; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000235:genetics* / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012441:Saccharomyces cerevisiae / Q000145:classification / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics* / Q000378:metabolism; D061806:Transcription Termination, Genetic
chemical_list: D020413:3' Untranslated Regions; D020121:5' Untranslated Regions; C096100:GAT1 protein, S cerevisiae; D050980:GATA Transcription Factors; D012333:RNA, Messenger; D029701:Saccharomyces cerevisiae Proteins; D009584:Nitrogen
keywords: yeast, transcription, initiation, termination, GAT1