scholarly journals Regulation of alpha-factor production in Saccharomyces cerevisiae: a-factor pheromone-induced expression of the MF alpha 1 and STE13 genes.

1989 ◽  
Vol 9 (10) ◽  
pp. 4507-4514 ◽  
Author(s):  
T Achstetter
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Fusion Gene ◽  
Invertase Activity ◽  
Transcriptional Level ◽  
Alpha Cells ◽  
Mating Pheromone ◽  
Induced Expression ◽  
Alpha Factor ◽  
Suc2 Gene ◽  
Proteolytic Activities

Production of the mating pheromone alpha-factor was examined in Saccharomyces cerevisiae MAT alpha cells that had been exposed to the mating pheromone a-factor. A 2-h treatment with a-factor caused a significant increase in alpha-factor concentration in the medium as demonstrated by a halo assay. MF alpha 1 is one of the two genes coding for a precursor of alpha-factor. A Northern (RNA) analysis of total RNA from a-factor-treated MAT alpha cells revealed a rapid two- to threefold increase in MF alpha 1 transcript levels, reaching maximum within 60 min of exposure to the pheromone. Pheromone induction did not require ongoing protein synthesis. a-Factor-induced MF alpha 1 expression was quantitated by analysis of an MF alpha 1::SUC2 fusion gene whose product was assayed for invertase activity. Expression of the MF alpha 1::SUC2 gene in MAT alpha cells responded to the a-factor signal like the chromosomal version of MF alpha 1. Maturation of the alpha-factor precursor involves three proteolytic activities which are encoded by the KEX1, KEX2, and STE13 genes, respectively. Two of these genes, namely, KEX2 and STE13, were examined for pheromone-induced expression. Only the STE13 gene exhibited pheromone induction at the transcriptional level.

Regulation of alpha-factor production in Saccharomyces cerevisiae: a-factor pheromone-induced expression of the MF alpha 1 and STE13 genes

1989 ◽  
Vol 9 (10) ◽  
pp. 4507-4514
Author(s):  
T Achstetter
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Fusion Gene ◽  
Invertase Activity ◽  
Transcriptional Level ◽  
Alpha Cells ◽  
Mating Pheromone ◽  
Induced Expression ◽  
Alpha Factor ◽  
Suc2 Gene ◽  
Proteolytic Activities

Production of the mating pheromone alpha-factor was examined in Saccharomyces cerevisiae MAT alpha cells that had been exposed to the mating pheromone a-factor. A 2-h treatment with a-factor caused a significant increase in alpha-factor concentration in the medium as demonstrated by a halo assay. MF alpha 1 is one of the two genes coding for a precursor of alpha-factor. A Northern (RNA) analysis of total RNA from a-factor-treated MAT alpha cells revealed a rapid two- to threefold increase in MF alpha 1 transcript levels, reaching maximum within 60 min of exposure to the pheromone. Pheromone induction did not require ongoing protein synthesis. a-Factor-induced MF alpha 1 expression was quantitated by analysis of an MF alpha 1::SUC2 fusion gene whose product was assayed for invertase activity. Expression of the MF alpha 1::SUC2 gene in MAT alpha cells responded to the a-factor signal like the chromosomal version of MF alpha 1. Maturation of the alpha-factor precursor involves three proteolytic activities which are encoded by the KEX1, KEX2, and STE13 genes, respectively. Two of these genes, namely, KEX2 and STE13, were examined for pheromone-induced expression. Only the STE13 gene exhibited pheromone induction at the transcriptional level.

scholarly journals Isolation and genetic analysis of Saccharomyces cerevisiae mutants supersensitive to G1 arrest by a factor and alpha factor pheromones.

1982 ◽  
Vol 2 (1) ◽  
pp. 11-20 ◽  
Author(s):  
R K Chan ◽  
C A Otte
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Mating Type ◽  
Solid Medium ◽  
G1 Arrest ◽  
Alpha Cells ◽  
Opposite Mating Type ◽  
Alpha Factor ◽  
Complementation Groups ◽  
Chromosome Iii ◽  
The Right

Eight independently isolated mutants which are supersensitive (Sst-) to the G1 arrest induced by the tridecapeptide pheromone alpha factor were identified by screening mutagenized Saccharomyces cerevisiae MATa cells on solid medium for increased growth inhibition by alpha factor. These mutants carried lesions in two complementation groups, sst1 and sst2. Mutations at the sst1 locus were mating type specific: MATa sst1 cells were supersensitive to alpha factor, but MAT alpha sst1 cells were not supersensitive to a factor. In contrast, mutations at the sst2 locus conferred supersensitivity to the pheromones of the opposite mating type on both MATa and MAT alpha cells. Even in the absence of added alpha pheromone, about 10% of the cells in exponentially growing cultures of MATa strains carrying any of three different alleles of sst2 (including the ochre mutation sst2-4) had the aberrant morphology ("shmoo" shape) that normally develops only after MATa cells are exposed to alpha factor. This "self-shmooing" phenotype was genetically linked to the sst2 mutations, although the leakiest allele isolated (sst2-3) did not display this characteristic. Normal MATa/MAT alpha diploids do not respond to pheromones; diploids homozygous for an sst2 mutation (MATa/MAT alpha sst2-1/sst2-1) were still insensitive to alpha factor. The sst1 gene was mapped to within 6.9 centimorgans of his6 on chromosome IX. The sst2 gene was unlinked to sst1, was not centromere linked, and was shown to be neither linked to nor centromere distal to MAT on the right arm of chromosome III.

scholarly journals Alpha-factor structural gene mutations in Saccharomyces cerevisiae: effects on alpha-factor production and mating.

1985 ◽  
Vol 5 (4) ◽  
pp. 787-796 ◽  
Author(s):  
J Kurjan
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Structural Gene ◽  
Gene Mutations ◽  
Alpha Cells ◽  
Structural Genes ◽  
Coding Region ◽  
Considerable Decrease ◽  
Factor Production ◽  
Alpha Factor

The role of alpha-factor structural genes MF alpha 1 and MF alpha 2 in alpha-factor production and mating has been investigated by the construction of mf alpha 1 and mf alpha 2 mutations that totally eliminate gene function. An mf alpha 1 mutant in which the entire coding region is deleted shows a considerable decrease in alpha-factor production and a 75% decrease in mating. Mutations in mf alpha 2 have little or no effect on alpha-factor production or mating. The mf alpha 1 mf alpha 2 double mutants are completely defective in mating and alpha-factor production. These results indicate that at least one alpha-factor structural gene product is required for mating in MAT alpha cells, that MF alpha 1 is responsible for the majority of alpha-factor production, and that MF alpha 1 and MF alpha 2 are the only active alpha-factor genes.

Isolation and genetic analysis of Saccharomyces cerevisiae mutants supersensitive to G1 arrest by a factor and alpha factor pheromones

1982 ◽  
Vol 2 (1) ◽  
pp. 11-20
Author(s):  
R K Chan ◽  
C A Otte
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Mating Type ◽  
Solid Medium ◽  
G1 Arrest ◽  
Alpha Cells ◽  
Opposite Mating Type ◽  
Alpha Factor ◽  
Complementation Groups ◽  
Chromosome Iii ◽  
The Right

Eight independently isolated mutants which are supersensitive (Sst-) to the G1 arrest induced by the tridecapeptide pheromone alpha factor were identified by screening mutagenized Saccharomyces cerevisiae MATa cells on solid medium for increased growth inhibition by alpha factor. These mutants carried lesions in two complementation groups, sst1 and sst2. Mutations at the sst1 locus were mating type specific: MATa sst1 cells were supersensitive to alpha factor, but MAT alpha sst1 cells were not supersensitive to a factor. In contrast, mutations at the sst2 locus conferred supersensitivity to the pheromones of the opposite mating type on both MATa and MAT alpha cells. Even in the absence of added alpha pheromone, about 10% of the cells in exponentially growing cultures of MATa strains carrying any of three different alleles of sst2 (including the ochre mutation sst2-4) had the aberrant morphology ("shmoo" shape) that normally develops only after MATa cells are exposed to alpha factor. This "self-shmooing" phenotype was genetically linked to the sst2 mutations, although the leakiest allele isolated (sst2-3) did not display this characteristic. Normal MATa/MAT alpha diploids do not respond to pheromones; diploids homozygous for an sst2 mutation (MATa/MAT alpha sst2-1/sst2-1) were still insensitive to alpha factor. The sst1 gene was mapped to within 6.9 centimorgans of his6 on chromosome IX. The sst2 gene was unlinked to sst1, was not centromere linked, and was shown to be neither linked to nor centromere distal to MAT on the right arm of chromosome III.

Multiple regulation of STE2, a mating-type-specific gene of Saccharomyces cerevisiae

1986 ◽  
Vol 6 (6) ◽  
pp. 2106-2114
Author(s):  
A Hartig ◽  
J Holly ◽  
G Saari ◽  
V L MacKay
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Gene Regulation ◽  
Gene Product ◽  
Mating Type ◽  
Type A ◽  
Specific Gene ◽  
Alpha Cells ◽  
Pheromone Response ◽  
Mating Pheromone ◽  
A Cells

The Saccharomyces cerevisiae STE2 gene, which is required for pheromone response and conjugation specifically in mating-type a cells, was cloned by complementation of the ste2 mutation. Transcription of STE2 is repressed by the MAT alpha 2 gene product, so that the 1.4-kilobase STE2 RNA is detected only in a or mat alpha 2 strains, not in alpha or a/alpha cells. However, STE2 RNA levels are also increased by the mating pheromone alpha-factor and decreased in strains bearing mutations in the nonspecific STE4 gene. Regulation of STE2 expression in a cells is therefore achieved by several mechanisms.

Alpha-factor structural gene mutations in Saccharomyces cerevisiae: effects on alpha-factor production and mating

1985 ◽  
Vol 5 (4) ◽  
pp. 787-796
Author(s):  
J Kurjan
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Structural Gene ◽  
Gene Mutations ◽  
Alpha Cells ◽  
Structural Genes ◽  
Coding Region ◽  
Considerable Decrease ◽  
Factor Production ◽  
Alpha Factor

The role of alpha-factor structural genes MF alpha 1 and MF alpha 2 in alpha-factor production and mating has been investigated by the construction of mf alpha 1 and mf alpha 2 mutations that totally eliminate gene function. An mf alpha 1 mutant in which the entire coding region is deleted shows a considerable decrease in alpha-factor production and a 75% decrease in mating. Mutations in mf alpha 2 have little or no effect on alpha-factor production or mating. The mf alpha 1 mf alpha 2 double mutants are completely defective in mating and alpha-factor production. These results indicate that at least one alpha-factor structural gene product is required for mating in MAT alpha cells, that MF alpha 1 is responsible for the majority of alpha-factor production, and that MF alpha 1 and MF alpha 2 are the only active alpha-factor genes.

scholarly journals SPT3 is required for normal levels of a-factor and alpha-factor expression in Saccharomyces cerevisiae.

1988 ◽  
Vol 8 (2) ◽  
pp. 822-827 ◽  
Author(s):  
J N Hirschhorn ◽  
F Winston
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Mating Type ◽  
Transcription Initiation ◽  
Nuclear Fusion ◽  
Mating Pheromone ◽  
Noncoding Regions ◽  
Factor Expression ◽  
Alpha Factor ◽  
Cellular Fusion ◽  
Insertion Mutations

Mutations in the Saccharomyces cerevisiae SPT3 gene were previously found to cause suppression of Ty and delta insertion mutations in 5'-noncoding regions of genes. This suppression likely results from the fact that SPT3 is required for transcription initiation in delta sequences. Other additional phenotypes of spt3 mutants, including a mating defect, suggest that SPT3 is required for normal levels of expression of other genes. We analyzed the mating defect in spt3 mutants and showed that the levels of transcripts of the three major mating pheromone genes, MF alpha 1, MFa1, MFa2, were all reduced. The reduction in expression of these genes in spt3 mutants was not due to expression of a silent mating type cassette. Furthermore, we showed that the spt3 mating defect was manifest at the levels of both cellular fusion and nuclear fusion.

scholarly journals Inhibition of glycogen synthesis in Saccharomyces cerevisiae by the mating pheromone alpha-factor.

1991 ◽  
Vol 266 (10) ◽  
pp. 6174-6180
Author(s):  
J François ◽  
D L Higgins ◽  
F Chang ◽  
K Tatchell
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Glycogen Synthesis ◽  
Mating Pheromone ◽  
Alpha Factor

scholarly journals Mutants of Saccharomyces cerevisiae unresponsive to cell division control by polypeptide mating hormone.

1980 ◽  
Vol 85 (3) ◽  
pp. 811-822 ◽  
Author(s):  
L H Hartwell
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Types ◽  
Temperature Sensitive ◽  
Restrictive Temperature ◽  
Alpha Cells ◽  
Wild Type ◽  
Cell Type ◽  
Mating Test ◽  
Alpha Factor ◽  
Cell Division Control

Temperature-sensitive mutations that produce insensitivity to division arrest by alpha-factor, a mating pheromone, were isolated in an MATa strain of Saccharomyces cerevisiae and shown by complementation studies to difine eight genes. All of these mutations (designated ste) produce sterility at the restrictive temperature in MATa cells, and mutations in seven of the genes produce sterility in MAT alpha cells. In no case was the sterility associated with these mutations coorectible by including wild-type cells of the same mating type in the mating test nor did nay of the mutants inhibit mating of the wild-type cells; the defect appears to be intrinsic to the cell for mutations in each of the genes. Apparently, none of the mutants is defective exclusively in division arrest by alpha-factor, as the sterility of none is suppressed by a temperature-sensitive cdc 28 mutation (the latter imposes division arrest at the correct cell cycle stage for mating). The mutants were examined for features that are inducible in MATa cells by alpha-factor (agglutinin synthesis as well as division arrest) and for the characteristics that constitutively distinguish MATa from MAT alpha cells (a-factor production, alpha-factor destruction). ste2 Mutants are defective specifically in the two inducible properties, whereas ste4, 5, 7, 8, 9, 11, and 12 mutants are defective, to varying degrees, in constitutive as well as inducible aspects. Mutations in ste8 and 9 assume a polar budding pattern unlike either MATa or MAT alpha cells but characteristic of MATa/alpha cells. This study defines seven genes that function in two cell types (MATa and alpha) to control the differentiation of cell type and one gene, ste2, that functions exclusively in MATa cells to mediate responsiveness to polypeptide hormone.

scholarly journals Bud formation by the yeast Saccharomyces cerevisiae is directly dependent on "start".

1984 ◽  
Vol 98 (2) ◽  
pp. 678-684 ◽  
Author(s):  
R A Singer ◽  
D P Bedard ◽  
G C Johnston
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Cycle ◽  
Gene Mutation ◽  
Mating Pheromone ◽  
Yeast Saccharomyces Cerevisiae ◽  
Bud Formation ◽  
Yeast Mating ◽  
Alpha Factor ◽  
Mutant Cells

Cells of the yeast Saccharomyces cerevisiae, which bear a cdc4 gene mutation, arrest early in the cell cycle but continue to produce buds in a periodic fashion. We show here that this periodic bud formation by cells already arrested at the CDC4 step is inhibited if the cell cycle regulatory step "start" is also specifically blocked by mutation or by the presence of the yeast mating pheromone alpha-factor. Thus, the characteristic periodic bud formation by cdc4 mutant cells requires the continued ability to perform start. This finding raises questions concerning the nature of start; these issues are discussed.

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