Two systems of glucose repression of the GAL1 promoter in Saccharomyces cerevisiae

1990 ◽  
Vol 10 (9) ◽  
pp. 4757-4769
Author(s):  
J S Flick ◽  
M Johnston
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Base Pair ◽  
Glucose Repression ◽  
Gene Products ◽  
Gal1 Promoter ◽  
Base Pair Fragment ◽  
Common Signal ◽  
Multiple Sequences ◽  
Pair Fragment ◽  
Gal1 Gene

Expression of the GAL1 gene in Saccharomyces cerevisiae is strongly repressed by growth on glucose. We show that two sites within the GAL1 promoter mediate glucose repression. First, glucose inhibits transcription activation by GAL4 protein through UASG. Second, a promoter element, termed URSG, confers glucose repression independently of GAL4. We have localized the URSG sequences responsible for glucose repression to an 87-base-pair fragment located between UASG and the TATA box. Promoters deleted for small (20-base-pair) segments that span this sequence are still subject to glucose repression, suggesting that there are multiple sequences within this region that confer repression. Extended deletions across this region confirm that it contains at least two and possibly three URSG elements. To identify the gene products that confer repression upon UASG and URSG, we have analyzed glucose repression mutants and found that the GAL83, REG1, GRR1, and SSN6 genes are required for repression mediated by both UASG and URSG. In contrast, GAL82 and HXK2 are required only for UASG repression. A mutation designated urr1-1 (URSG repression resistant) was identified that specifically relieves URSG repression without affecting UASG repression. In addition, we observed that the SNF1-encoded protein kinase is essential for derepression of both UASG and URSG. We propose that repression of UASG and URSG is mediated by two independent pathways that respond to a common signal generated by growth on glucose.

scholarly journals Two systems of glucose repression of the GAL1 promoter in Saccharomyces cerevisiae.

1990 ◽  
Vol 10 (9) ◽  
pp. 4757-4769 ◽  
Author(s):  
J S Flick ◽  
M Johnston
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Base Pair ◽  
Glucose Repression ◽  
Gene Products ◽  
Gal1 Promoter ◽  
Base Pair Fragment ◽  
Common Signal ◽  
Multiple Sequences ◽  
Pair Fragment ◽  
Gal1 Gene

Expression of the GAL1 gene in Saccharomyces cerevisiae is strongly repressed by growth on glucose. We show that two sites within the GAL1 promoter mediate glucose repression. First, glucose inhibits transcription activation by GAL4 protein through UASG. Second, a promoter element, termed URSG, confers glucose repression independently of GAL4. We have localized the URSG sequences responsible for glucose repression to an 87-base-pair fragment located between UASG and the TATA box. Promoters deleted for small (20-base-pair) segments that span this sequence are still subject to glucose repression, suggesting that there are multiple sequences within this region that confer repression. Extended deletions across this region confirm that it contains at least two and possibly three URSG elements. To identify the gene products that confer repression upon UASG and URSG, we have analyzed glucose repression mutants and found that the GAL83, REG1, GRR1, and SSN6 genes are required for repression mediated by both UASG and URSG. In contrast, GAL82 and HXK2 are required only for UASG repression. A mutation designated urr1-1 (URSG repression resistant) was identified that specifically relieves URSG repression without affecting UASG repression. In addition, we observed that the SNF1-encoded protein kinase is essential for derepression of both UASG and URSG. We propose that repression of UASG and URSG is mediated by two independent pathways that respond to a common signal generated by growth on glucose.

scholarly journals REPRESSION OF MEIOTIC CROSSING OVER BY A CENTROMERE (CEN3) IN SACCHAROMYCES CEREVISIAE

Genetics ◽  
1986 ◽  
Vol 114 (3) ◽  
pp. 769-789
Author(s):  
Eric J Lambie ◽  
G Shirleen Roeder
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Base Pair ◽  
Crossing Over ◽  
Base Pair Fragment ◽  
Chromosome Iii ◽  
Pair Fragment

ABSTRACT The location of the centromere of chromosome III (CEN3) of Saccharomyces cerevisiae has been altered by means of transformation. The frequency of meiotic crossing over in the CEN3-PGK1 and LEU2-CEN3 intervals increases approximately 1.5- and fourfold, respectively, when CEN3 is repositioned at HIS4. The centromere-distal HIS4-LEU2 region experiences a three- to fivefold decrease in the frequency of meiotic exchange when CEN3 is repositioned at HIS4. The inhibition of meiotic crossing over is conferred by a 627-base-pair fragment of CEN3 DNA and is not dependent on the orientation of CEN3 relative to the rest of chromosome III.

scholarly journals An RNA polymerase I enhancer in Saccharomyces cerevisiae.

1986 ◽  
Vol 6 (6) ◽  
pp. 2089-2097 ◽  
Author(s):  
E A Elion ◽  
J R Warner
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Rna Polymerase ◽  
Base Pair ◽  
Transcription Initiation ◽  
Initiation Site ◽  
Rna Polymerase I ◽  
Promoter Element ◽  
Base Pair Fragment ◽  
Polymerase I ◽  
Pair Fragment

By the use of an artificial gene coding for rRNA (rDNA gene), we found that transcription of the major precursor rRNA in Saccharomyces cerevisiae cells is stimulated 15-fold by a positive control element located 2 kilobases upstream of the transcription initiation site. Analysis of in vitro runon transcripts suggests that this promoter element increases the frequency of initiation by RNA polymerase I molecules. A 190-base-pair fragment encompassing the promoter element can stimulate transcription on a centromere plasmid in either orientation, upstream or downstream of the transcription initiation site, suggesting that it is an enhancer element. Integration of artificial rDNA genes into a nonribosomal locus in the genome demonstrates that the rDNA enhancer functions either 5' or 3' to an rRNA transcription unit, suggesting it may operate in both directions within the rDNA tandem array. This is the first observation in S. cerevisiae of the stimulation of transcription by an element placed downstream. Finally, enhancer activity is dependent upon sequences that lie at both boundaries of the 190-base-pair fragment. In particular, a 5-base-pair deletion at the extreme 3' boundary of the 190-base-pair fragment greatly reduces the activation of transcription and implicates a set of inverted repeats.

An RNA polymerase I enhancer in Saccharomyces cerevisiae

1986 ◽  
Vol 6 (6) ◽  
pp. 2089-2097
Author(s):  
E A Elion ◽  
J R Warner
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Rna Polymerase ◽  
Base Pair ◽  
Transcription Initiation ◽  
Initiation Site ◽  
Rna Polymerase I ◽  
Promoter Element ◽  
Base Pair Fragment ◽  
Polymerase I ◽  
Pair Fragment

By the use of an artificial gene coding for rRNA (rDNA gene), we found that transcription of the major precursor rRNA in Saccharomyces cerevisiae cells is stimulated 15-fold by a positive control element located 2 kilobases upstream of the transcription initiation site. Analysis of in vitro runon transcripts suggests that this promoter element increases the frequency of initiation by RNA polymerase I molecules. A 190-base-pair fragment encompassing the promoter element can stimulate transcription on a centromere plasmid in either orientation, upstream or downstream of the transcription initiation site, suggesting that it is an enhancer element. Integration of artificial rDNA genes into a nonribosomal locus in the genome demonstrates that the rDNA enhancer functions either 5' or 3' to an rRNA transcription unit, suggesting it may operate in both directions within the rDNA tandem array. This is the first observation in S. cerevisiae of the stimulation of transcription by an element placed downstream. Finally, enhancer activity is dependent upon sequences that lie at both boundaries of the 190-base-pair fragment. In particular, a 5-base-pair deletion at the extreme 3' boundary of the 190-base-pair fragment greatly reduces the activation of transcription and implicates a set of inverted repeats.

scholarly journals Suppressors reveal two classes of glucose repression genes in the yeast Saccharomyces cerevisiae.

Genetics ◽  
1994 ◽  
Vol 136 (4) ◽  
pp. 1271-1278 ◽  
Author(s):  
J R Erickson ◽  
M Johnston
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Glucose Repression ◽  
Single Gene ◽  
The Other ◽  
Gene Products ◽  
Yeast Saccharomyces Cerevisiae ◽  
Similar Point ◽  
Normal Glucose ◽  
Gal Genes ◽  
Extragenic Suppressors

Abstract We selected and analyzed extragenic suppressors of mutations in four genes--GRR1, REG1, GAL82 and GAL83-required for glucose repression of the GAL genes in the yeast Saccharomyces cerevisiae. The suppressors restore normal or nearly normal glucose repression of GAL1 expression in these glucose repression mutants. Tests of the ability of each suppressor to cross-suppress mutations in the other glucose repression genes revealed two groups of mutually cross-suppressed genes: (1) REG1, GAL82 and GAL83 and (2) GRR1. Mutations of a single gene, SRG1, were found as suppressors of reg1, GAL83-2000 and GAL82-1, suggesting that these three gene products act at a similar point in the glucose repression pathway. Mutations in SRG1 do not cross-suppress grr1 or hxk2 mutations. Conversely, suppressors of grr1 (rgt1) do not cross-suppress any other glucose repression mutation tested. These results, together with what was previously known about these genes, lead us to propose a model for glucose repression in which Grr1p acts early in the glucose repression pathway, perhaps affecting the generation of the signal for glucose repression. We suggest that Reg1p, Gal82p and Gal83p act after the step(s) executed by Grr1p, possibly transmitting the signal for repression to the Snf1p protein kinase.

Null mutations in the SNF3 gene of Saccharomyces cerevisiae cause a different phenotype than do previously isolated missense mutations

1986 ◽  
Vol 6 (11) ◽  
pp. 3569-3574
Author(s):  
L Neigeborn ◽  
P Schwartzberg ◽  
R Reid ◽  
M Carlson
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Glucose Uptake ◽  
Gene Disruption ◽  
Glucose Repression ◽  
Gene Products ◽  
Missense Mutations ◽  
Chromosomal Locus ◽  
Growth Properties ◽  
Invertase Gene ◽  
Regulatory Functions

Missense mutations in the SNF3 gene of Saccharomyces cerevisiae were previously found to cause defects in both glucose repression and derepression of the SUC2 (invertase) gene. In addition, the growth properties of snf3 mutants suggested that they were defective in uptake of glucose and fructose. We have cloned the SNF3 gene by complementation and demonstrated linkage of the cloned DNA to the chromosomal SNF3 locus. The gene encodes a 3-kilobase poly(A)-containing RNA, which was fivefold more abundant in cells deprived of glucose. The SNF3 gene was disrupted at its chromosomal locus by several methods to create null mutations. Disruption resulted in growth phenotypes consistent with a defect in glucose uptake. Surprisingly, gene disruption did not cause aberrant regulation of SUC2 expression. We discuss possible mechanisms by which abnormal SNF3 gene products encoded by missense alleles could perturb regulatory functions.

scholarly journals Characterization of the human p53 gene promoter.

1989 ◽  
Vol 9 (5) ◽  
pp. 2163-2172 ◽  
Author(s):  
S P Tuck ◽  
L Crawford
Keyword(s):  
Base Pair ◽  
Accurate Determination ◽  
Gene Promoter ◽  
Simian Virus 40 ◽  
P53 Gene ◽  
Simian Virus ◽  
Stem Loop ◽  
Base Pair Fragment ◽  
Exon 1 ◽  
Pair Fragment

Transcriptional deregulation of the p53 gene may play an important part in the genesis of some tumors. We report here an accurate determination of the transcriptional start sites of the human p53 gene and show that the majority of p53 mRNA molecules do not contain a postulated stem-loop structure at their 5' ends. Recombinant plasmids of the human p53 promoter-leader region fused to the bacterial chloramphenicol acetyltransferase gene (cat) were constructed. After transfection into rodent or human cells, a 350-base-pair fragment spanning the promoter region conferred 4% of the CAT activity mediated by the simian virus 40 early promoter/enhancer. We monitored the efficiency with which 15 3' and 5' promoter deletion constructs initiated transcription. Our results show that an 85-base-pair fragment, previously thought to have resided in exon 1, is all that is required for full promoter activity.

scholarly journals Null mutations in the SNF3 gene of Saccharomyces cerevisiae cause a different phenotype than do previously isolated missense mutations.

1986 ◽  
Vol 6 (11) ◽  
pp. 3569-3574 ◽  
Author(s):  
L Neigeborn ◽  
P Schwartzberg ◽  
R Reid ◽  
M Carlson
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Glucose Uptake ◽  
Gene Disruption ◽  
Glucose Repression ◽  
Gene Products ◽  
Missense Mutations ◽  
Chromosomal Locus ◽  
Growth Properties ◽  
Invertase Gene ◽  
Regulatory Functions

Missense mutations in the SNF3 gene of Saccharomyces cerevisiae were previously found to cause defects in both glucose repression and derepression of the SUC2 (invertase) gene. In addition, the growth properties of snf3 mutants suggested that they were defective in uptake of glucose and fructose. We have cloned the SNF3 gene by complementation and demonstrated linkage of the cloned DNA to the chromosomal SNF3 locus. The gene encodes a 3-kilobase poly(A)-containing RNA, which was fivefold more abundant in cells deprived of glucose. The SNF3 gene was disrupted at its chromosomal locus by several methods to create null mutations. Disruption resulted in growth phenotypes consistent with a defect in glucose uptake. Surprisingly, gene disruption did not cause aberrant regulation of SUC2 expression. We discuss possible mechanisms by which abnormal SNF3 gene products encoded by missense alleles could perturb regulatory functions.

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