GENES AFFECTING THE REGULATION OF SUC2 GENE EXPRESSION BY GLUCOSE REPRESSION IN SACCHAROMYCES CEREVISIAE

Genetics ◽  
1984 ◽  
Vol 108 (4) ◽  
pp. 845-858
Author(s):  
Lenore Neigeborn ◽  
Marian Carlson
Keyword(s):  
Gene Expression ◽  
Saccharomyces Cerevisiae ◽  
Glucose Repression ◽  
Invertase Activity ◽  
Recessive Mutations ◽  
Glycerol Utilization ◽  
Suc2 Gene ◽  
Complementation Groups ◽  
Low Levels ◽  
High Level

ABSTRACT Mutants of Saccharomyces cerevisiae with defects in sucrose or raffinose fermentation were isolated. In addition to mutations in the SUC2 structural gene for invertase, we recovered 18 recessive mutations that affected the regulation of invertase synthesis by glucose repression. These mutations included five new snf1 (sucrose nonfermenting) alleles and also defined five new complementation groups, designated snf2, snf3, snf4, snf5 and snf6. The snf2, snf4 and snf5 mutants produced little or no secreted invertase under derepressing conditions and were pleiotropically defective in galactose and glycerol utilization, which are both regulated by glucose repression. The snf6 mutant produced low levels of secreted invertase under derepressing conditions, and no pleiotropy was detected. The snf3 mutants derepressed secreted invertase to 10-35% the wild-type level but grew less well on sucrose than expected from their invertase activity; in addition, snf3 mutants synthesized some invertase under glucose-repressing conditions.—We examined the interactions between the different snf mutations and ssn6, a mutation causing constitutive (glucose-insensitive) high-level invertase synthesis that was previously isolated as a suppressor of snf1 . The ssn6 mutation completely suppressed the defects in derepression of invertase conferred by snf1, snf3, snf4 and snf6, and each double mutant showed the constitutivity for invertase typical of ssn6 single mutants. In contrast, snf2 ssn6 and snf5 ssn6 strains produced only moderate levels of invertase under derepressing conditions and very low levels under repressing conditions. These findings suggest roles for the SNF1 through SNF6 and SSN6 genes in the regulation of SUC2 gene expression by glucose repression.

Upstream region required for regulated expression of the glucose-repressible SUC2 gene of Saccharomyces cerevisiae

1984 ◽  
Vol 4 (12) ◽  
pp. 2750-2757
Author(s):  
L Sarokin ◽  
M Carlson
Keyword(s):  
Gene Expression ◽  
Glucose Repression ◽  
Transcriptional Start Site ◽  
Upstream Region ◽  
Yeast Genome ◽  
Base Pairs ◽  
Regulated Expression ◽  
Suc2 Gene ◽  
High Level

The SUC2 gene produces two mRNAs with different 5' ends that encode two forms of invertase. The 1.9-kilobase mRNA encoding secreted invertase is regulated by glucose repression (carbon catabolite repression), and the 1.8-kilobase mRNA encoding intracellular invertase is produced constitutively at low levels. To identify 5' noncoding sequences essential for regulated expression of SUC2, we constructed in vitro a series of deletions and inserted them into the yeast genome at the chromosomal SUC2 locus. Analysis of the effects of each deletion on SUC2 gene expression identified an upstream region required for derepression of secreted invertase synthesis. The 3' boundary of this region is near -418. The 5' boundary does not appear to be sharply defined, but lies ca. 100 base pairs upstream. A deletion extending from -418 to -140 allowed high-level derepression, indicating that no essential sequences lie between the upstream region and the TATA box at -133 and that the upstream region can be moved 279 base pairs closer to the transcriptional start site. Interactions between the deletions and several unlinked mutations affecting the regulation of SUC2 gene expression were examined. Sequences between -1,900 and -86 are dispensable for expression of the 1.8-kilobase mRNA.

scholarly journals Upstream region required for regulated expression of the glucose-repressible SUC2 gene of Saccharomyces cerevisiae.

1984 ◽  
Vol 4 (12) ◽  
pp. 2750-2757 ◽  
Author(s):  
L Sarokin ◽  
M Carlson
Keyword(s):  
Gene Expression ◽  
Glucose Repression ◽  
Transcriptional Start Site ◽  
Upstream Region ◽  
Yeast Genome ◽  
Base Pairs ◽  
Regulated Expression ◽  
Suc2 Gene ◽  
High Level

The SUC2 gene produces two mRNAs with different 5' ends that encode two forms of invertase. The 1.9-kilobase mRNA encoding secreted invertase is regulated by glucose repression (carbon catabolite repression), and the 1.8-kilobase mRNA encoding intracellular invertase is produced constitutively at low levels. To identify 5' noncoding sequences essential for regulated expression of SUC2, we constructed in vitro a series of deletions and inserted them into the yeast genome at the chromosomal SUC2 locus. Analysis of the effects of each deletion on SUC2 gene expression identified an upstream region required for derepression of secreted invertase synthesis. The 3' boundary of this region is near -418. The 5' boundary does not appear to be sharply defined, but lies ca. 100 base pairs upstream. A deletion extending from -418 to -140 allowed high-level derepression, indicating that no essential sequences lie between the upstream region and the TATA box at -133 and that the upstream region can be moved 279 base pairs closer to the transcriptional start site. Interactions between the deletions and several unlinked mutations affecting the regulation of SUC2 gene expression were examined. Sequences between -1,900 and -86 are dispensable for expression of the 1.8-kilobase mRNA.

scholarly journals A SUPPRESSOR OF snf1 MUTATIONS CAUSES CONSTITUTIVE HIGH-LEVEL INVERTASE SYNTHESIS IN YEAST

Genetics ◽  
1984 ◽  
Vol 107 (1) ◽  
pp. 19-32
Author(s):  
Marian Carlson ◽  
Barbara C Osmond ◽  
Lenore Neigeborn ◽  
David Botstein
Keyword(s):  
Genetic Characterization ◽  
Glucose Repression ◽  
Invertase Activity ◽  
Complementation Group ◽  
Regulatory Function ◽  
Wild Type ◽  
Suppressor Mutations ◽  
Complementation Groups ◽  
High Level

ABSTRACT The SNF1 gene product of Saccharomyces cerevisiae is required to derepress expression of many glucose-repressible genes, including the SUC2 structural gene for invertase. Strains carrying a recessive snf1 mutation are unable to ferment sucrose. We have isolated 30 partial phenotypic revertants of a snf1 mutant that were able to ferment sucrose. Genetic characterization of these revertants showed that the suppressor mutations were all recessive and defined eight complementation groups, designated ssn1 through ssn8 (suppressor of snf1). The revertants were assayed for secreted invertase activity, and although activity was detected in members of each complementation group, only the ssn6 strains contained wild-type levels. Synthesis of secreted invertase in ssn6 strains was found to be constitutive, that is, insensitive to glucose repression; moreover, the ssn6 mutations also conferred constitutivity in a wild-type (SNF1) genetic background and are, therefore, not merely suppressors of snf1. Pleiotropic defects were observed in ssn6 mutants. Genetic analysis suggested that the ssn6 mutations are allelic to the cyc8 mutation isolated by R. J. Rothstein and F. Sherman, which causes increased production of iso-2-cytochrome c. The data suggest a regulatory function for SSN6.

scholarly journals MUTANTS OF YEAST DEFECTIVE IN SUCROSE UTILIZATION

Genetics ◽  
1981 ◽  
Vol 98 (1) ◽  
pp. 25-40
Author(s):  
Marian Carlson ◽  
Barbara C Osmond ◽  
David Botstein
Keyword(s):  
Glucose Repression ◽  
Single Gene ◽  
Regulation Of Gene Expression ◽  
Carbon Sources ◽  
Invertase Activity ◽  
Carbon Utilization ◽  
Recessive Mutations ◽  
Complementation Groups ◽  
General Defect ◽  
Sucrose Utilization

ABSTRACT Utilization of sucrose as a source of carbon and energy in yeast (Saccharomyces) is controlled by the classical SUC genes, which confer the ability to produce the sucrose-degrading enzyme invertase (Mortimer and Hawthorne 1969). Mutants of S. cerevisiae strain S288C (SUC2  +) unable to grow anaerobically on sucrose, but still able to use glucose, were isolated. Two major complementation groups were identified: twenty-four recessive mutations at the SUC2 locus (suc2  -); and five recessive mutations defining a new locus, SNF1 (for sucrose nonfermenting), essential for sucrose utilization. Two minor complementation groups, each comprising a single member with a leaky sucrose-nonfermenting phenotype, were also identified. The suc2 mutations isolated include four suppressible amber mutations and five mutations apparently exhibiting intragenic complementation; complementation analysis and mitotic mapping studies indicated that all of the suc2 mutations are alleles of a single gene. These results suggest that SUC2 encodes a protein, probably a dimer or multimer. No invertase activity was detected in suc2 mutants.—The SNF1 locus is not tightly linked to SUC2. The snf1 mutations were found to be pleiotropic, preventing sucrose utilization by SUC2  + and SUC7  + strains, and also preventing utilization of galactose, maltose and several nonfermentable carbon sources. Although snf1 mutants thus display a petite phenotype, classic petite mutations do not interfere with utilization of sucrose, galactose or maltose. A common feature of all the carbon utilization systems affected by SNF1 is that all are regulated by glucose repression. The snf1 mutants were found to produce the constitutive nonglycosylated form of invertase, but failed to produce the glucose-repressible, glycosylated, secreted invertase. This failure cannot be attributed to a general defect in production of glycosylated and secreted proteins because synthesis of acid phosphatase, a glycosylated secreted protein not subject to glucose repression, was not affected by snf1 mutations. These findings suggest that the SNF1 locus is involved in the regulation of gene expression by glucose repression.

Molecular analysis of SNF2 and SNF5, genes required for expression of glucose-repressible genes in Saccharomyces cerevisiae

1986 ◽  
Vol 6 (11) ◽  
pp. 3643-3651
Author(s):  
E Abrams ◽  
L Neigeborn ◽  
M Carlson
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Acid Phosphatase ◽  
Molecular Analysis ◽  
Glucose Repression ◽  
Glucose Deprivation ◽  
Invertase Activity ◽  
Multiple Copy ◽  
High Level Expression ◽  
Chromosomal Locus ◽  
High Level

The SNF2 and SNF5 genes are required for derepression of SUC2 and other glucose-repressible genes of Saccharomyces cerevisiae in response to glucose deprivation. Previous genetic evidence suggested that SNF2 and SNF5 have functionally related roles. We cloned both genes by complementation and showed that the cloned DNA was tightly linked to the corresponding chromosomal locus. Both genes in multiple copy complemented only the cognate snf mutation. The SNF2 gene encodes a 5.7-kilobase RNA, and the SNF5 gene encodes a 3-kilobase RNA. Both RNAs contained poly(A) and were present in low abundance. Neither was regulated by glucose repression, and the level of SNF2 RNA was not dependent on SNF5 function or vice versa. Disruption of either gene at its chromosomal locus still allowed low-level derepression of secreted invertase activity, suggesting that these genes are required for high-level expression but are not directly involved in regulation. Further evidence was the finding that snf2 and snf5 mutants failed to derepress acid phosphatase, which is not regulated by glucose repression. The SNF2 and SNF5 functions were required for derepression of SUC2 mRNA.

scholarly journals Molecular analysis of SNF2 and SNF5, genes required for expression of glucose-repressible genes in Saccharomyces cerevisiae.

1986 ◽  
Vol 6 (11) ◽  
pp. 3643-3651 ◽  
Author(s):  
E Abrams ◽  
L Neigeborn ◽  
M Carlson
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Acid Phosphatase ◽  
Molecular Analysis ◽  
Glucose Repression ◽  
Glucose Deprivation ◽  
Invertase Activity ◽  
Multiple Copy ◽  
High Level Expression ◽  
Chromosomal Locus ◽  
High Level

The SNF2 and SNF5 genes are required for derepression of SUC2 and other glucose-repressible genes of Saccharomyces cerevisiae in response to glucose deprivation. Previous genetic evidence suggested that SNF2 and SNF5 have functionally related roles. We cloned both genes by complementation and showed that the cloned DNA was tightly linked to the corresponding chromosomal locus. Both genes in multiple copy complemented only the cognate snf mutation. The SNF2 gene encodes a 5.7-kilobase RNA, and the SNF5 gene encodes a 3-kilobase RNA. Both RNAs contained poly(A) and were present in low abundance. Neither was regulated by glucose repression, and the level of SNF2 RNA was not dependent on SNF5 function or vice versa. Disruption of either gene at its chromosomal locus still allowed low-level derepression of secreted invertase activity, suggesting that these genes are required for high-level expression but are not directly involved in regulation. Further evidence was the finding that snf2 and snf5 mutants failed to derepress acid phosphatase, which is not regulated by glucose repression. The SNF2 and SNF5 functions were required for derepression of SUC2 mRNA.

Mutations Causing Constitutive Invertase Synthesis in Yeast: Genetic Interactions with snf Mutations

Genetics ◽  
1987 ◽  
Vol 115 (2) ◽  
pp. 247-253
Author(s):  
Lenore Neigeborn ◽  
Marian Carlson
Keyword(s):  
Regulatory Region ◽  
Constitutive Expression ◽  
Genetic Interactions ◽  
The Third ◽  
Recessive Mutations ◽  
Constitutive Mutation ◽  
Complementation Groups ◽  
High Level ◽  
Yeast Genetic ◽  
Very High

ABSTRACT We have selected 210 mutants able to grow on sucrose in the presence of 2-deoxyglucose. We identified recessive mutations in three major complementation groups that cause constitutive (glucose-insensitive) secreted invertase synthesis. Two groups comprise alleles of the previously identified HXK2 and REG1 genes, and the third group was designated cid1 (constitutive invertase derepression). The effect of cid1 on SUC2 expression is mediated by the SUC2 upstream regulatory region, as judged by the constitutive expression of a SUC2-LEU2-lacZ fusion in which the LEU2 promoter is under control of SUC2 upstream sequences. A cid1 mutation also causes glucose-insensitive expression of maltase. The previously isolated constitutive mutation ssn6 is epistatic to cid1, reg1 and hxk2 for very high level constitutive invertase expression. Mutations in SNF genes that prevent derepression of invertase are epistatic to cid1, reg1 and hxk2; we have previously shown that ssn6 has different epistasis relationships with snf mutations. The constitutive mutation tup1 was found to resemble ssn6 in its genetic interactions with snf mutations. These findings suggest that CID1, REG1 and HXK2 are functionally distinct from SSN6 and TUP1.

High-level heterologous gene expression in Saccharomyces cerevisiae from a stable 2μm plasmid system

Gene ◽  
1993 ◽  
Vol 132 (1) ◽  
pp. 33-40 ◽  
Author(s):  
Dale L. Ludwig ◽  
Simone Ugolini ◽  
Carlo V. Bruschi
Keyword(s):  
Gene Expression ◽  
Saccharomyces Cerevisiae ◽  
Heterologous Gene Expression ◽  
Heterologous Gene ◽  
High Level

RPD3 encodes a second factor required to achieve maximum positive and negative transcriptional states in Saccharomyces cerevisiae

1991 ◽  
Vol 11 (12) ◽  
pp. 6317-6327 ◽  
Author(s):  
M Vidal ◽  
R F Gaber
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Target Genes ◽  
Current Data ◽  
Regulatory Function ◽  
Fourfold Increase ◽  
Recessive Mutations ◽  
Activation Of Transcription ◽  
Transcriptional Regulatory ◽  
Low Levels ◽  
Full Activation

In Saccharomyces cerevisiae, TRK1 and TRK2 encode the high- and low-affinity K+ transporters, respectively. In cells containing a deletion of TRK1, transcription levels of TRK2 are extremely low and are limiting for growth in media containing low levels of K+ (Trk- phenotype). Recessive mutations in RPD1 and RPD3 suppress the TRK2, conferring an approximately fourfold increase in transcription. rpd3 mutations confer pleiotropic phenotypes, including (i) mating defects, (ii) hypersensitivity to cycloheximide, (iii) inability to sporulate as homozygous diploids, and (iv) constitutive derepression of acid phosphatase. RPD3 was cloned and is predicted to encode a 48-kDa protein with no extensive similarity to proteins contained in current data bases. Deletion of RPD3 is not lethal but confers phenotypes identical to those caused by spontaneous mutations. RPD3 is required for both full repression and full activation of transcription of target genes including PHO5, STE6, and TY2. RPD3 is the second gene required for this function, since RPD1 is also required. The effects of mutations in RPD1 and RPD3 are not additive, suggesting that these genes are involved in the same transcriptional regulatory function or pathway.

scholarly journals Divergent MLS1 promoters lie on a fitness plateau for gene expression

2015 ◽  
Author(s):  
Andrew C Bergen ◽  
Gerilyn M Olsen ◽  
Justin C Fay
Keyword(s):  
Gene Expression ◽  
Saccharomyces Cerevisiae ◽  
Dynamic Response ◽  
Yeast Species ◽  
Glucose Repression ◽  
Gene Activation ◽  
Malate Synthase ◽  
Expression Divergence ◽  
Fitness Effects ◽  
Single Promoter

Qualitative patterns of gene activation and repression are often conserved despite an abundance of quantitative variation in expression levels within and between species. A major challenge to interpreting patterns of expression divergence is knowing which changes in gene expression affect fitness. To characterize the fitness effects of gene expression divergence we placed orthologous promoters from eight yeast species upstream of malate synthase (MLS1) in Saccharomyces cerevisiae. As expected, we found these promoters varied in their expression level under activated and repressed conditions as well as in their dynamic response following loss of glucose repression. Despite these differences, only a single promoter driving near basal levels of expression caused a detectable loss of fitness. We conclude that the MLS1 promoter lies on a fitness plateau whereby even large changes in gene expression can be tolerated without a substantial loss of fitness.

Sign in / Sign up

Export Citation Format

Share Document