title: Avoiding unscheduled transcription in shared promoters: Saccharomyces cerevisiae Sum1p represses the divergent gene pair SPS18-SPS19 through a midsporulation element (MSE).
abstract: The sporulation-specific gene SPS18 shares a common promoter region with the oleic acid-inducible gene SPS19. Both genes are transcribed in sporulating diploid cells, albeit unevenly in favour of SPS18, whereas in haploid cells grown on fatty acids only SPS19 is highly activated. Here, SPS19 oleate-response element (ORE) conferred activation on a basal CYC1-lacZ reporter gene equally in both orientations, but promoter analysis using SPS18-lacZ reporter constructs with deletions identified a repressing fragment containing a midsporulation element (MSE) that could be involved in imposing directionality towards SPS19 in oleic acid-induced cells. In sporulating diploids, MSEs recruit the Ndt80p transcription factor for activation, whereas under vegetative conditions, certain MSEs are targeted by the Sum1p repressor in association with Hst1p and Rfm1p. Quantitative real-time PCR demonstrated that in haploid sum1Delta, hst1Delta, or rfm1Delta cells, oleic acid-dependent expression of SPS18 was higher compared with the situation in wild-type cells, but in the sum1Delta mutant, this effect was diminished in the absence of Oaf1p or Pip2p. We conclude that SPS18 MSE is a functional element repressing the expression of both SPS18 and SPS19, and is a component of a stricture mechanism shielding SPS18 from the dramatic increase in ORE-dependent transcription of SPS19 in oleic acid-grown cells.
authors: Center for Physiology, Pathophysiology and Immunology, Institute of Physiology, Section of Physiology of Lipid Metabolism, Medical University of Vienna, Vienna, Austria. aner.gurvitz@meduniwien.ac.at
authors: Aner
authors: A
authors: Gurvitz
authors: Fumi
authors: F
authors: Suomi
authors: Hanspeter
authors: H
authors: Rottensteiner
authors: J Kalervo
authors: JK
authors: Hiltunen
authors: Ian W
authors: IW
authors: Dawes
mesh_terms: D019677:Artificial Gene Fusion; D001483:Base Sequence; D015966:Gene Expression Regulation, Fungal; D005800:Genes, Fungal; D017930:Genes, Reporter; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000502:physiology*; D011401:Promoter Regions, Genetic; D012097:Repressor Proteins / Q000502:physiology*; D012441:Saccharomyces cerevisiae / Q000502:physiology*; D029701:Saccharomyces cerevisiae Proteins / Q000502:physiology*; D013172:Spores, Fungal / Q000502:physiology*; D014158:Transcription, Genetic; D001616:beta-Galactosidase / Q000378:metabolism
chemical_list: D009687:Nuclear Proteins; D012097:Repressor Proteins; C100925:SUM1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D001616:beta-Galactosidase