title: The yeast repeated element sigma contains a hormone-inducible promoter.
abstract: A genomic clone (lambda ScG7) from Saccharomyces cerevisiae encoded a 650-nucleotide poly(A)-containing [poly(A)+] RNA that was about 50 times more abundant in MATa cells that had been exposed to the peptide pheromone alpha-factor than in untreated cells. This RNA was transcribed from a cluster of repetitive sequences: both intact and truncated delta and sigma elements adjacent to a tRNATrp gene. Strand-specific probes indicated that this RNA initiated within an intact sigma element and contained sigma sequences at its 5' end. MATa cells produced two other prominent poly(A)+ RNAs (500 and 5,300 bases) in response to alpha-factor that were homologous to the same strand of sigma but transcribed from other locations in the genome. Induction of the sigma-related transcripts was rapid, was not blocked by inhibition of protein synthesis, required a functional receptor (STE2 gene product), and hence appeared to be a primary response to pheromone. Pulse-labeling confirmed that accumulation of sigma RNA following alpha-factor administration was accounted for by an increase in its rate of transcription. The sigma RNAs also were induced in MAT alpha cells that had been treated with a-factor, but were not present at significant levels in MATa/MAT alpha diploids. In MATa cells transformed with a plasmid in which the lambda ScG7 sigma element was inserted just upstream of a gene coding for the intracellular form of invertase (SUC2) lacking its own promoter, a new poly(A)+ RNA (2.2 kilobases) appeared in response to alpha-factor that hybridized to both sigma and SUC2 probes, and intracellular invertase activity was elevated about 10-fold within 30 min. Primer extension showed that transcription from the hybrid gene initiated exclusively within the sigma sequence (117 nucleotides from the 3' end of the element).
mesh_terms: D002874:Chromosome Mapping; D005786:Gene Expression Regulation; D006026:Glycoside Hydrolases / Q000235:genetics; D000072235:Mating Factor; D010455:Peptides / Q000502:physiology*; D011401:Promoter Regions, Genetic; D012331:RNA, Fungal / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000235:genetics; D012091:Repetitive Sequences, Nucleic Acid; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D014158:Transcription, Genetic; D043324:beta-Fructofuranosidase
chemical_list: D010455:Peptides; D012331:RNA, Fungal; D011993:Recombinant Fusion Proteins; D000072235:Mating Factor; D006026:Glycoside Hydrolases; D043324:beta-Fructofuranosidase