scholarly journals Regulation of STA1 gene expression by MAT during the life cycle of Saccharomyces cerevisiae.

1989 ◽  
Vol 9 (9) ◽  
pp. 3992-3998 ◽  
Author(s):  
A M Dranginis
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Mating Type ◽  
Yeast Cells ◽  
Specific Gene ◽  
Activity Levels ◽  
Sporulation Medium ◽  
Mrna Levels ◽  
Yeast Saccharomyces Cerevisiae ◽  
Type Locus ◽  
Diploid Cells

STA1 encodes a secreted glucoamylase of the yeast Saccharomyces cerevisiae var. diastaticus. Glucoamylase secretion is controlled by the mating type locus MAT; a and alpha haploid yeast cells secrete high levels of the enzyme, but a/alpha diploid cells produce undetectable amounts. It has been suggested that STA1 is regulated by MATa2 (I. Yamashita, Y. Takano, and S. Fukui, J. Bacteriol. 164:769-773, 1985), which is a MAT transcript of previously unknown function. In contrast, this work shows that deletion of the entire MATa2 gene had no effect on STA1 regulation but that deletion of MATa1 sequences completely abolished mating-type control. In all cases, glucoamylase activity levels reflected STA1 mRNA levels. It appears that STA1 is a haploid-specific gene that is regulated by MATa1 and a product of the MAT alpha locus and that this regulation occurs at the level of RNA accumulation. STA1 expression was also shown to be glucose repressible. STA1 mRNA was induced in diploids during sporulation along with SGA, a closely linked gene that encodes an intracellular sporulation-specific glucoamylase of S. cerevisiae. A diploid strain with a MATa1 deletion showed normal induction of STA1 in sporulation medium, but SGA expression was abolished. Therefore, these two homologous and closely linked glucoamylase genes are induced by different mechanisms during sporulation. STA1 induction may be a response to the starvation conditions necessary for sporulation, while SGA induction is governed by the pathway by which MAT regulates sporulation. The strain containing a complete deletion of MATa2 grew, mated, and sporulated normally.

Regulation of STA1 gene expression by MAT during the life cycle of Saccharomyces cerevisiae

1989 ◽  
Vol 9 (9) ◽  
pp. 3992-3998
Author(s):  
A M Dranginis
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Mating Type ◽  
Yeast Cells ◽  
Specific Gene ◽  
Activity Levels ◽  
Sporulation Medium ◽  
Mrna Levels ◽  
Yeast Saccharomyces Cerevisiae ◽  
Type Locus ◽  
Diploid Cells

STA1 encodes a secreted glucoamylase of the yeast Saccharomyces cerevisiae var. diastaticus. Glucoamylase secretion is controlled by the mating type locus MAT; a and alpha haploid yeast cells secrete high levels of the enzyme, but a/alpha diploid cells produce undetectable amounts. It has been suggested that STA1 is regulated by MATa2 (I. Yamashita, Y. Takano, and S. Fukui, J. Bacteriol. 164:769-773, 1985), which is a MAT transcript of previously unknown function. In contrast, this work shows that deletion of the entire MATa2 gene had no effect on STA1 regulation but that deletion of MATa1 sequences completely abolished mating-type control. In all cases, glucoamylase activity levels reflected STA1 mRNA levels. It appears that STA1 is a haploid-specific gene that is regulated by MATa1 and a product of the MAT alpha locus and that this regulation occurs at the level of RNA accumulation. STA1 expression was also shown to be glucose repressible. STA1 mRNA was induced in diploids during sporulation along with SGA, a closely linked gene that encodes an intracellular sporulation-specific glucoamylase of S. cerevisiae. A diploid strain with a MATa1 deletion showed normal induction of STA1 in sporulation medium, but SGA expression was abolished. Therefore, these two homologous and closely linked glucoamylase genes are induced by different mechanisms during sporulation. STA1 induction may be a response to the starvation conditions necessary for sporulation, while SGA induction is governed by the pathway by which MAT regulates sporulation. The strain containing a complete deletion of MATa2 grew, mated, and sporulated normally.

INTERCONVERSION OF YEAST MATING TYPES II. RESTORATION OF MATING ABILITY TO STERILE MUTANTS IN HOMOTHALLIC AND HETEROTHALLIC STRAINS

Genetics ◽  
1977 ◽  
Vol 85 (3) ◽  
pp. 373A-393
Author(s):  
James B Hicks ◽  
Ira Herskowitz
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Mating Type ◽  
Yeast Cells ◽  
Mating Types ◽  
Yeast Saccharomyces Cerevisiae ◽  
Type Locus ◽  
Mating Ability ◽  
Mating Type Locus ◽  
Regulatory Information ◽  
Ho Gene

ABSTRACT The two mating types of the yeast Saccharomyces cerevisiae can be interconverted in both homothallic and heterothallic strains. Previous work indicates that all yeast cells contain the information to be both a and α and that the HO gene (in homothallic strains) promotes a change in mating type by causing a change at the mating type locus itself. In both heterothallic and homothallic strains, a defective α mating type locus can be converted to a functional a locus and subsequently to a functional α locus. In contrast, action of the HO gene does not restore mating ability to a strain defective in another gene for mating which is not at the mating type locus. These observations indicate that a yeast cell contains an additional copy (or copies) of α information, and lead to the "cassette" model for mating type interconversion. In this model, HM  a and hmα loci are blocs of unexpressed α regulatory information, and HMα and hm  a loci are blocs of unexpressed a regulatory information. These blocs are silent because they lack an essential site for expression, and become active upon insertion of this information (or a copy of the information) into the mating type locus by action of the HO gene.

Transcriptional control of the sporulation-specific glucoamylase gene in the yeast Saccharomyces cerevisiae

1985 ◽  
Vol 5 (11) ◽  
pp. 3069-3073
Author(s):  
I Yamashita ◽  
S Fukui
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Mating Type ◽  
Transcriptional Control ◽  
Northern Blot Analysis ◽  
Insertion Mutation ◽  
Yeast Saccharomyces Cerevisiae ◽  
Type Locus ◽  
Mating Type Genes ◽  
Diploid Cells ◽  
Glucoamylase Gene

In the yeast Saccharomyces cerevisiae, glucoamylase activity appears specifically in sporulating cells heterozygous for the mating-type locus (MAT). We identified a sporulation-specific glucoamylase gene (SGA) and show that expression of SGA is positively regulated by the mating-type genes, both MATa1 and MAT alpha 2. Northern blot analysis revealed that control of SGA is exerted at the level of RNA production. Expression of SGA or the consequent degradation of glycogen to glucose in cells is not required for meiosis or sporulation, since MATa/MAT alpha diploid cells homozygous for an insertion mutation at SGA still formed four viable ascospores.

scholarly journals Transcriptional control of the sporulation-specific glucoamylase gene in the yeast Saccharomyces cerevisiae.

1985 ◽  
Vol 5 (11) ◽  
pp. 3069-3073 ◽  
Author(s):  
I Yamashita ◽  
S Fukui
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Mating Type ◽  
Transcriptional Control ◽  
Northern Blot Analysis ◽  
Insertion Mutation ◽  
Yeast Saccharomyces Cerevisiae ◽  
Type Locus ◽  
Mating Type Genes ◽  
Diploid Cells ◽  
Glucoamylase Gene

In the yeast Saccharomyces cerevisiae, glucoamylase activity appears specifically in sporulating cells heterozygous for the mating-type locus (MAT). We identified a sporulation-specific glucoamylase gene (SGA) and show that expression of SGA is positively regulated by the mating-type genes, both MATa1 and MAT alpha 2. Northern blot analysis revealed that control of SGA is exerted at the level of RNA production. Expression of SGA or the consequent degradation of glycogen to glucose in cells is not required for meiosis or sporulation, since MATa/MAT alpha diploid cells homozygous for an insertion mutation at SGA still formed four viable ascospores.

Identification of sequence elements that confer cell-type-specific control of MF alpha 1 expression in Saccharomyces cerevisiae

1987 ◽  
Vol 7 (9) ◽  
pp. 3185-3193
Author(s):  
K Inokuchi ◽  
A Nakayama ◽  
F Hishinuma
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Mating Type ◽  
Specific Gene ◽  
Cell Type ◽  
Coding Region ◽  
Transcription Start ◽  
Specific Expression ◽  
Type Locus ◽  
Mating Type Locus ◽  
Cell Type Specific

The MF alpha 1 gene of Saccharomyces cerevisiae, a major structural gene for mating pheromone alpha factor, is an alpha-specific gene whose expression is regulated by the mating-type locus. To study the role of sequences upstream of MF alpha 1 in its expression and regulation, we generated two sets of promoter deletions: upstream deletions and internal deletions. By analyzing these deletions, we have identified a TATA box and two closely related, tandemly arranged upstream activation sites as necessary elements for MF alpha 1 expression. Two upstream activation sites were located ca. 300 and 250 base pairs upstream of the MF alpha 1 transcription start points, which were also determined in this study. Each site contained a homologous 22-base-pair sequence, and both sites were required for maximum transcription level. The distance between the upstream activation sites and the transcription start points could be altered without causing loss of transcription efficiency, and the sites were active in either orientation with respect to the coding region. These elements conferred cell type-specific expression on a heterologous promoter. Analysis with host mating-type locus mutants indicates that these sequences are the sites through which the MAT alpha 1 product exerts its action to activate the MF alpha 1 gene. Homologous sequences with these elements were found in other alpha-specific genes, MF alpha 2 and STE3, and may mediate activation of this set of genes by MAT alpha 1.

scholarly journals Evidence for cooperation between cells during sporulation of the yeast Saccharomyces cerevisiae.

1988 ◽  
Vol 8 (12) ◽  
pp. 5166-5178 ◽  
Author(s):  
H Jakubowski ◽  
E Goldman
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Density ◽  
De Novo ◽  
High Cell Density ◽  
Degradation Products ◽  
Yeast Cells ◽  
High Cell ◽  
Yeast Saccharomyces Cerevisiae ◽  
Type Locus ◽  
Low Cell Density

Diploid Saccharomyces cerevisiae cells heterozygous for the mating type locus (MATa/MAT alpha) undergo meiosis and sporulation when starved for nitrogen in the presence of a poor carbon source such as potassium acetate. Diploid yeast adenine auxotrophs sporulated well at high cell density (10(7) cells per ml) under these conditions but failed to differentiate at low cell density (10(5) cells per ml). The conditional sporulation-deficient phenotype of adenine auxotrophs could be complemented by wild-type yeast cells, by medium from cultures that sporulate at high cell density, or by exogenously added adenine (or hypoxanthine with some mutants). Adenine and hypoxanthine in addition to guanine, adenosine, and numerous nucleotides were secreted into the medium, each in its unique temporal pattern, by sporulating auxotrophic and prototrophic yeast strains. The major source of these compounds was degradation of RNA. The data indicated that differentiating yeast cells cooperate during sporulation in maintaining sufficiently high concentrations of extracellular purines which are absolutely required for sporulation of adenine auxotrophs. Yeast prototrophs, which also sporulated less efficiently at low cell density (10(3) cells per ml), reutilized secreted purines in preference to de novo-made purine nucleotides whose synthesis was in fact inhibited during sporulation at high cell density. Adenine enhanced sporulation of yeast prototrophs at low cell density. The behavior of adenine auxotrophs bearing additional mutations in purine salvage pathway genes (ade apt1, ade aah1 apt1, ade hpt1) supports a model in which secretion of degradation products, uptake, and reutilization of these products is a signal between cells synchronizing the sporulation process.

scholarly journals MATING-TYPE REGULATION OF METHYL METHANESULFONATE SENSITIVITY IN SACCHAROMYCES CEREVISIAE

Genetics ◽  
1980 ◽  
Vol 95 (2) ◽  
pp. 259-271
Author(s):  
George P Livi ◽  
Vivian L Mackay
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Mating Type ◽  
S Phase ◽  
Methyl Methanesulfonate ◽  
Survival Curves ◽  
Repair Capacity ◽  
Type Locus ◽  
X Ray ◽  
G2 Phase ◽  
Diploid Cells

ABSTRACT Heterozygosity at the mating-type locus (MAT) in Saccharomyces cerevisiae has been shown previously to enhance X-ray survival in diploid cells. We now show that a/α diploids are also more resistant to the radiomimetic agent methyl methanesulfonate (MMS) that are diploids that are homozygous at MAT (i.e., either a/a or α/α). Log-phase a/α cultures exhibit biphasic MMS survival curves, in which the more resistant fraction consists of budded cells (those cells in the S and G2 phases of the cell cycle). Survival curves for log-phase cultures of a/a or α/α diploids have little if any biphasic nature, suggesting that the enhanced S- and G2-phase repair capacity of a/α cells may be associated with heterozygosity at MAT. The survival of cells arrested at the beginning of the S phase with hydroxyurea indicates that MAT-dependent MMS repair is limited to S and G2, whereas MAT-independent repair can occur in Gl.

scholarly journals DEPENDENCE ON MATING TYPE FOR THE OVERPRODUCTION OF ISO-2-CYTOCHROME c IN THE YEAST MUTANT CYC7–H2

Genetics ◽  
1980 ◽  
Vol 94 (4) ◽  
pp. 891-898
Author(s):  
Rodney J Rothstein ◽  
Fred Sherman
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cytochrome C ◽  
Mating Type ◽  
Regulatory Region ◽  
The Other ◽  
Yeast Mutant ◽  
Yeast Saccharomyces Cerevisiae ◽  
Type Locus ◽  
Active Expression ◽  
Structural Region

ABSTRACT The CYC7-H2 mutation causes an approximately 20-fold overproduction of iso-2-cytochromo c in a and α haploid strains of the yeast Saccharomyces cerevisiae due to an alteration in the nontranslated regulatory region that is presumably contiguous with the structural region. In this investigation, we demonstrated that heterozygosity at the mating type locus, a /α or a/a/α/α, prevents expression of the overproduction, while homozygosity, a/a and α/α and hemizygosity, a/O and α/O, allow full expression of the CYC7-H2 mutation, equivalent to the expression observed in a and α haploid strains. There is no decrease in the overproduction of iso-2-cytochrome c in a/α diploid strains containing either of the other two similar mutations, CYC7-H1 and CYC7-H3. It appears as if active expression of one or another of the mating-type alleles is required for the overproduction of iso-2-cytochrome c in CYC7-H2 mutants.

scholarly journals Mechanisms that ensure monogamous mating in Saccharomyces cerevisiae

2021 ◽  
pp. mbc.E20-12-0757
Author(s):  
Corrina G. Robertson ◽  
Manuella R. Clark-Cotton ◽  
Daniel J. Lew
Keyword(s):  
Gene Expression ◽  
Saccharomyces Cerevisiae ◽  
Mating Type ◽  
Multiple Mating ◽  
The Other ◽  
Specific Gene ◽  
Fusion Event ◽  
Yeast Saccharomyces Cerevisiae ◽  
Multiple Partners ◽  
Potential Partner

Haploid cells of the budding yeast Saccharomyces cerevisiae communicate using secreted pheromones and mate to form diploid zygotes. Mating is monogamous, resulting in the fusion of precisely one cell of each mating type. Monogamous mating in crowded conditions, where cells have access to more than one potential partner, raises the question of how multiple-mating outcomes are prevented. Here we identify mutants capable of mating with multiple partners, revealing the mechanisms that ensure monogamous mating. Before fusion, cells develop polarity foci oriented towards potential partners. Competition between these polarity foci within each cell leads to disassembly of all but one focus, thus favoring a single fusion event. Fusion promotes the formation of heterodimeric complexes between subunits that are uniquely expressed in each mating type. One complex shuts off haploid-specific gene expression, and the other shuts off the ability to respond to pheromone. Zygotes able to form either complex remain monogamous, but zygotes lacking both can re-mate.

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