title: STA10 repression of STA gene expression is caused by a defective activator, flo8, in Saccharomyces cerevisiae.
abstract: The expression of STA genes that encode extracellular glucoamylase isozymes is repressed in most laboratory Saccharomyces cerevisiae strains, which are believed to contain an undefined repressor, designated STA10. To identify the regulator involved in STA10 repression, we investigate the FLO8, MSN1, MSS11, STE12, and TEC1 genes. The Deltaflo8 or Deltamss11 deletion mutants in the sta10 genetic background exhibit both a loss of flocculation ability and a reduction in extracellular glucoamylase activity, as in the STA10 strain. Moreover, the STA10 repression is suppressed completely or partially by the introduction of a single copy of the FLO8 or MSS11 genes. Sequence analysis and complementation testing of the STA10 strain reveal that it has an inactive, mutated flo8-1 allele. A random spore analysis and transplacement (allele replacement) experiment confirms that the repressive phenotype of STA10 is due to the amber mutation of the transcriptional activator, FLO8.
authors.affiliation: School of Biological Sciences, Seoul National University, Shillim-Dong, Kwanak-Gu, 151-742 Seoul, Korea.
authors.forename: Tae Soo
authors.initials: TS
authors.lastname: Kim
authors.forename: Ji Yeon
authors.initials: JY
authors.lastname: Ahn
authors.forename: Jin Ho
authors.initials: JH
authors.lastname: Yoon
authors.forename: Hyen Sam
authors.initials: HS
authors.lastname: Kang
mesh_terms: D000483:Alleles; D015971:Gene Expression Regulation, Enzymologic; D015966:Gene Expression Regulation, Fungal; D005087:Glucan 1,4-alpha-Glucosidase / Q000096:biosynthesis / Q000235:genetics*; D009154:Mutation; D009687:Nuclear Proteins / Q000235:genetics / Q000502:physiology*; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000502:physiology*; D013489:Suppression, Genetic; D015534:Trans-Activators / Q000235:genetics / Q000502:physiology*; D014157:Transcription Factors
chemical_list: C100940:FLO8 protein, S cerevisaie; C109358:MSS11 protein, S cerevisiae; D009687:Nuclear Proteins; D029701:Saccharomyces cerevisiae Proteins; D015534:Trans-Activators; D014157:Transcription Factors; D005087:Glucan 1,4-alpha-Glucosidase