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.

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.

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.

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.

Identification of regulatory regions within the Ty1 transposable element that regulate iso-2-cytochrome c production in the CYC7-H2 yeast mutant

1984 ◽  
Vol 4 (7) ◽  
pp. 1393-1401
Author(s):  
B Errede ◽  
T S Cardillo ◽  
M A Teague ◽  
F Sherman
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cytochrome C ◽  
Transposable Element ◽  
Yeast Cells ◽  
Yeast Mutant ◽  
Yeast Saccharomyces Cerevisiae ◽  
Specific Restriction ◽  
Restriction Endonuclease Cleavage

The CYC7-H2 mutation in the yeast Saccharomyces cerevisiae was caused by insertion of a Ty1 transposable element in front of the iso-2-cytochrome c structural gene, CYC7. The Ty1 insertion places iso-2-cytochrome c production under control of regulatory signals that are normally required for mating functions in yeast cells. We have investigated the regions of the Ty1 insertion that are responsible for the aberrant production of iso-2-cytochrome c in the CYC7-H2 mutant. Five alterations of the CYC7-H2 gene were obtained by specific restriction endonuclease cleavage of the cloned DNA and ligation of appropriate fragments. The CYC7+, CYC7-H2, and modified CYC7-H2 genes were each inserted into the yeast vector YIp5 and used to transform a cytochrome c-deficient yeast strain. Expression and regulation of each allele integrated at the CYC7 locus have been compared in vivo by determination of the amount of iso-2-cytochrome c produced. These results show that distal regions of the Ty1 element are not essential for the CYC7-H2 overproducing phenotype. In contrast, alterations in the vicinity of the proximal Ty1 junction abolish the CYC7-H2 expression and give rise to different phenotypes.

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 Identification of regulatory regions within the Ty1 transposable element that regulate iso-2-cytochrome c production in the CYC7-H2 yeast mutant.

1984 ◽  
Vol 4 (7) ◽  
pp. 1393-1401 ◽  
Author(s):  
B Errede ◽  
T S Cardillo ◽  
M A Teague ◽  
F Sherman
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cytochrome C ◽  
Transposable Element ◽  
Yeast Cells ◽  
Yeast Mutant ◽  
Yeast Saccharomyces Cerevisiae ◽  
Specific Restriction ◽  
Restriction Endonuclease Cleavage

The CYC7-H2 mutation in the yeast Saccharomyces cerevisiae was caused by insertion of a Ty1 transposable element in front of the iso-2-cytochrome c structural gene, CYC7. The Ty1 insertion places iso-2-cytochrome c production under control of regulatory signals that are normally required for mating functions in yeast cells. We have investigated the regions of the Ty1 insertion that are responsible for the aberrant production of iso-2-cytochrome c in the CYC7-H2 mutant. Five alterations of the CYC7-H2 gene were obtained by specific restriction endonuclease cleavage of the cloned DNA and ligation of appropriate fragments. The CYC7+, CYC7-H2, and modified CYC7-H2 genes were each inserted into the yeast vector YIp5 and used to transform a cytochrome c-deficient yeast strain. Expression and regulation of each allele integrated at the CYC7 locus have been compared in vivo by determination of the amount of iso-2-cytochrome c produced. These results show that distal regions of the Ty1 element are not essential for the CYC7-H2 overproducing phenotype. In contrast, alterations in the vicinity of the proximal Ty1 junction abolish the CYC7-H2 expression and give rise to different phenotypes.

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.

scholarly journals Structure of the Saccharomyces cerevisiae HO gene and analysis of its upstream regulatory region.

1986 ◽  
Vol 6 (12) ◽  
pp. 4281-4294 ◽  
Author(s):  
D W Russell ◽  
R Jensen ◽  
M J Zoller ◽  
J Burke ◽  
B Errede ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Mating Type ◽  
Dna Sequences ◽  
Regulatory Region ◽  
Initiation Codon ◽  
Upstream Region ◽  
Lacz Gene ◽  
Type Locus ◽  
Reading Frame ◽  
Ho Gene

The HO gene product of Saccharomyces cerevisiae is a site-specific endonuclease that initiates mating type interconversion. We have determined the nucleotide sequence of a 3,129-base-pair (bp) segment containing HO. The segment contains a single long open reading frame encoding a polypeptide of 586 amino acids, which has unusual (unbiased) codon usage and is preceded by 762 bp of upstream region. The predicted HO protein is basic (16% lysine and arginine) and is calculated to have a secondary structure that is 30% helical. The corresponding transcript is initiated approximately 50 nucleotides prior to the presumed initiation codon. Insertion of an Escherichia coli lacZ gene fragment into the putative HO coding segment inactivated HO and formed a hybrid HO-lacZ gene whose beta-galactosidase activity was regulated by the mating type locus in the same manner as HO (repressed by a 1-alpha 2). Upstream regions of 1,360 and 762 bp conferred strong repression; 436 bp led to partial constitutivity and 301 bp to full constitutivity. Thus, DNA sequences that confer repression of HO by a1-alpha 2 are at least 250 nucleotides upstream of the transcription start point and are within 436 nucleotides of the HO initiation codon. The progressive loss of repression suggests that both the -762 to -436 and the -436 to -301 intervals contain sites for regulation by a1-alpha 2. The HO gene contains two distinct regions that promote autonomous replication of plasmids in S. cerevisiae. These regions contain sequences that are homologous to the two conserved sequences that are associated with ARS activity.

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.

Sign in / Sign up

Export Citation Format

Share Document