scholarly journals Identification of a DNA segment that is necessary and sufficient for alpha-specific gene control in Saccharomyces cerevisiae: implications for regulation of alpha-specific and a-specific genes.

1988 ◽  
Vol 8 (1) ◽  
pp. 309-320 ◽  
Author(s):  
E E Jarvis ◽  
D C Hagen ◽  
G F Sprague
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Binding Site ◽  
Transcript Level ◽  
Cell Types ◽  
Specific Gene ◽  
Alpha Cells ◽  
Transcription Activator ◽  
Noncoding Sequences ◽  
Necessary And Sufficient ◽  
Activation Sequence

STE3 mRNA is present only in Saccharomyces cerevisiae alpha cells, not in a or a/alpha cells, and the transcript level increases about fivefold when cells are treated with a-factor mating pheromone. Deletions in the 5' noncoding region of STE3 defined a 43-base-pair (bp) upstream activation sequence (UAS) that can impart both modes of regulation to a CYC1-lacZ fusion when substituted for the native CYC1 UAS. UAS activity required the alpha 1 product of MAT alpha, which is known to be required for transcription of alpha-specific genes. A chromosomal deletion that removed only 14 bp of the STE3 UAS reduced STE3 transcript levels 50- to 100-fold, indicating that the UAS is essential for expression. The STE3 UAS shares a 26-bp homology with the 5' noncoding sequences of the only other known alpha-specific genes, MF alpha 1 and MF alpha 2. We view the homology as having two components--a nearly palindromic 16-bp "P box" and an adjacent 10-bp "Q box." A synthetic STE3 P box was inactive as a UAS; a perfect palindrome P box was active in all three cell types. We propose that the P box is the binding site for a transcription activator, but that alpha 1 acting via the Q box is required for this activator to bind to the imperfect P boxes of alpha-specific genes. Versions of the P box are also found upstream of a-specific genes, within the binding sites of the repressor alpha 2 encoded by MAT alpha. Thus, the products of MAT alpha may render gene expression alpha or a-specific by controlling access of the same transcription activator to its binding site, the P box.

Identification of a DNA segment that is necessary and sufficient for alpha-specific gene control in Saccharomyces cerevisiae: implications for regulation of alpha-specific and a-specific genes

1988 ◽  
Vol 8 (1) ◽  
pp. 309-320 ◽  
Author(s):  
E E Jarvis ◽  
D C Hagen ◽  
G F Sprague
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Binding Site ◽  
Transcript Level ◽  
Cell Types ◽  
Specific Gene ◽  
Alpha Cells ◽  
Transcription Activator ◽  
Noncoding Sequences ◽  
Necessary And Sufficient ◽  
Activation Sequence

STE3 mRNA is present only in Saccharomyces cerevisiae alpha cells, not in a or a/alpha cells, and the transcript level increases about fivefold when cells are treated with a-factor mating pheromone. Deletions in the 5' noncoding region of STE3 defined a 43-base-pair (bp) upstream activation sequence (UAS) that can impart both modes of regulation to a CYC1-lacZ fusion when substituted for the native CYC1 UAS. UAS activity required the alpha 1 product of MAT alpha, which is known to be required for transcription of alpha-specific genes. A chromosomal deletion that removed only 14 bp of the STE3 UAS reduced STE3 transcript levels 50- to 100-fold, indicating that the UAS is essential for expression. The STE3 UAS shares a 26-bp homology with the 5' noncoding sequences of the only other known alpha-specific genes, MF alpha 1 and MF alpha 2. We view the homology as having two components--a nearly palindromic 16-bp "P box" and an adjacent 10-bp "Q box." A synthetic STE3 P box was inactive as a UAS; a perfect palindrome P box was active in all three cell types. We propose that the P box is the binding site for a transcription activator, but that alpha 1 acting via the Q box is required for this activator to bind to the imperfect P boxes of alpha-specific genes. Versions of the P box are also found upstream of a-specific genes, within the binding sites of the repressor alpha 2 encoded by MAT alpha. Thus, the products of MAT alpha may render gene expression alpha or a-specific by controlling access of the same transcription activator to its binding site, the P box.

scholarly journals Transcription of alpha-specific genes in Saccharomyces cerevisiae: DNA sequence requirements for activity of the coregulator alpha 1.

1993 ◽  
Vol 13 (11) ◽  
pp. 6866-6875 ◽  
Author(s):  
D C Hagen ◽  
L Bruhn ◽  
C A Westby ◽  
G F Sprague
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Binding Site ◽  
Dna Sequences ◽  
Point Mutations ◽  
Transcription Activation ◽  
Specific Gene ◽  
Binding Assays ◽  
Weak Binding

Transcription activation of alpha-specific genes in Saccharomyces cerevisiae is regulated by two proteins, MCM1 and alpha 1, which bind to DNA sequences, called P'Q elements, found upstream of alpha-specific genes. Neither MCM1 nor alpha 1 alone binds efficiently to P'Q elements. Together, however, they bind cooperatively in a manner that requires both the P' sequence, which is a weak binding site for MCM1, and the Q sequence, which has been postulated to be the binding site for alpha 1. We analyzed a collection of point mutations in the P'Q element of the STE3 gene to determine the importance of individual base pairs for alpha-specific gene transcription. Within the 10-bp conserved Q sequence, mutations at only three positions strongly affected transcription activation in vivo. These same mutations did not affect the weak binding to P'Q displayed by MCM1 alone. In vitro DNA binding assays showed a direct correlation between the ability of the mutant sequences to form ternary P'Q-MCM1-alpha 1 complexes and the degree to which transcription was activated in vivo. Thus, the ability of alpha 1 and MCM1 to bind cooperatively to P'Q elements is critical for activation of alpha-specific genes. In all natural alpha-specific genes the Q sequence is adjacent to the degenerate side of P'. To test the significance of this geometry, we created several novel juxtapositions of P, P', and Q sequences. When the Q sequence was opposite the degenerate side, the composite QP' element was inactive as a promoter element in vivo and unable to form stable ternary QP'-MCM1-alpha 1 complexes in vitro. We also found that addition of a Q sequence to a strong MCM1 binding site allows the addition of alpha 1 to the complex. This finding, together with the observation that Q-element point mutations affected ternary complex formation but not the weak binding of MCM1 alone, supports the idea that the Q sequence serves as a binding site for alpha 1.

scholarly journals The SPS4 gene of Saccharomyces cerevisiae encodes a major sporulation-specific mRNA.

1986 ◽  
Vol 6 (12) ◽  
pp. 4478-4485 ◽  
Author(s):  
A T Garber ◽  
J Segall
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Polyacrylamide Gel Electrophoresis ◽  
Specific Protein ◽  
Polyacrylamide Gel ◽  
In Vitro Translation ◽  
Specific Gene ◽  
Alpha Cells ◽  
Two Dimensional ◽  
Isoelectric Ph

The SPS4 gene of Saccharomyces cerevisiae, a sporulation-specific gene identified previously in a differential hybridization screen of a genomic yeast DNA library, has been characterized further. The protein encoded by this gene was inferred from its nucleotide sequence to be 38,600 daltons with an isoelectric pH of 8.2. Consistent with this, two-dimensional polyacrylamide gel electrophoresis of the in vitro translation products of RNA purified by hybridization with the cloned SPS4 DNA indicated that the SPS4 gene product is a 39-kilodalton, basic protein. This protein was found to be identical in size and charge to a major, sporulation-specific protein identified in a two-dimensional polyacrylamide gel electrophoretic comparison of the in vitro translation products of total RNA from sporulating MATa/MAT alpha cells and asporogenous MAT alpha/MAT alpha cells. A MATa/MAT alpha strain homozygous for a partial deletion of the SPS4 gene appeared, however, to be unaffected in its ability to form viable ascospores.

scholarly journals Role of IME1 expression in regulation of meiosis in Saccharomyces cerevisiae.

1990 ◽  
Vol 10 (12) ◽  
pp. 6103-6113 ◽  
Author(s):  
H E Smith ◽  
S S Su ◽  
L Neigeborn ◽  
S E Driscoll ◽  
A P Mitchell
Keyword(s):  
Gene Expression ◽  
Saccharomyces Cerevisiae ◽  
Amino Acid ◽  
Specific Gene ◽  
Alpha Cells ◽  
Cell Type ◽  
Yeast Saccharomyces Cerevisiae ◽  
Specific Gene Expression ◽  
Gal1 Promoter ◽  
Acid Protein

Two signals are required for meiosis and spore formation in the yeast Saccharomyces cerevisiae: starvation and the MAT products a1 and alpha 2, which determine the a/alpha cell type. These signals lead to increased expression of the IME1 (inducer of meiosis) gene, which is required for sporulation and sporulation-specific gene expression. We report here the sequence of the IME1 gene and the consequences of IME1 expression from the GAL1 promoter. The deduced IME1 product is a 360-amino-acid protein with a tyrosine-rich C-terminal region. Expression of PGAL1-IME1 in vegetative a/alpha cells led to moderate accumulation of four early sporulation-specific transcripts (IME2, SPO11, SPO13, and HOP1); the transcripts accumulated 3- to 10-fold more after starvation. Two sporulation-specific transcripts normally expressed later (SPS1 and SPS2) did not accumulate until PGAL1-IME1 strains were starved, and the intact IME1 gene was not activated by PGAL1-IME1 expression. In a or alpha cells, which lack alpha 2 or a1, expression of PGAL1-IME1 led to the same pattern of IME2 and SPO13 expression as in a/alpha cells, as measured with ime2::lacZ and spo13::lacZ fusions. Thus, in wild-type strains, the increased expression of IME1 in starved a/alpha cells can account entirely for cell type control, but only partially for nutritional control, of early sporulation-specific gene expression. PGAL1-IME1 expression did not cause growing cells to sporulate but permitted efficient sporulation of amino acid-limited cells, which otherwise sporulated poorly. We suggest that IME1 acts primarily as a positive regulator of early sporulation-specific genes and that growth arrest is an independent prerequisite for execution of the sporulation program.

scholarly journals Yeast alpha 2 repressor positions nucleosomes in TRP1/ARS1 chromatin.

1990 ◽  
Vol 10 (5) ◽  
pp. 2247-2260 ◽  
Author(s):  
S Y Roth ◽  
A Dean ◽  
R T Simpson
Keyword(s):  
Binding Site ◽  
Mating Type ◽  
Chromatin Structure ◽  
Nucleosome Position ◽  
Cell Types ◽  
Alpha Cells ◽  
Cell Type ◽  
Yeast Plasmid ◽  
A Cells ◽  
Cell Type Specific

The yeast alpha 2 repressor suppresses expression of a-mating-type-specific genes in haploid alpha and diploid a/alpha cell types. We inserted the alpha 2-binding site into the multicopy TRP1/ARS1 yeast plasmid and examined the effects of alpha 2 on the chromatin structure of the derivative plasmids in alpha cells, and a/alpha cells. Whereas no effect on nucleosome position was observed in a cells, nucleosomes were precisely and stably positioned over sequences flanking the alpha 2 operator in alpha and a/alpha cells. In addition, when the alpha 2 operator was located upstream of the TRP1 gene, an extended array of positioned nucleosomes was formed in alpha cells and a/alpha cells, with formation of a nucleosome not present in a cells, and TRP1 mRNA production was substantially reduced. These data indicate that alpha 2 causes a positioning of nucleosomes over sequences proximal to its operator in TRP1/ARS1 chromatin and suggest that changes in chromatin structure may be related to alpha 2 repression of cell-type-specific genes.

Yeast alpha 2 repressor positions nucleosomes in TRP1/ARS1 chromatin

1990 ◽  
Vol 10 (5) ◽  
pp. 2247-2260
Author(s):  
S Y Roth ◽  
A Dean ◽  
R T Simpson
Keyword(s):  
Binding Site ◽  
Mating Type ◽  
Chromatin Structure ◽  
Nucleosome Position ◽  
Cell Types ◽  
Alpha Cells ◽  
Cell Type ◽  
Yeast Plasmid ◽  
A Cells ◽  
Cell Type Specific

The yeast alpha 2 repressor suppresses expression of a-mating-type-specific genes in haploid alpha and diploid a/alpha cell types. We inserted the alpha 2-binding site into the multicopy TRP1/ARS1 yeast plasmid and examined the effects of alpha 2 on the chromatin structure of the derivative plasmids in alpha cells, and a/alpha cells. Whereas no effect on nucleosome position was observed in a cells, nucleosomes were precisely and stably positioned over sequences flanking the alpha 2 operator in alpha and a/alpha cells. In addition, when the alpha 2 operator was located upstream of the TRP1 gene, an extended array of positioned nucleosomes was formed in alpha cells and a/alpha cells, with formation of a nucleosome not present in a cells, and TRP1 mRNA production was substantially reduced. These data indicate that alpha 2 causes a positioning of nucleosomes over sequences proximal to its operator in TRP1/ARS1 chromatin and suggest that changes in chromatin structure may be related to alpha 2 repression of cell-type-specific genes.

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.

scholarly journals Isolation of DNA sequences preferentially expressed during sporulation in Saccharomyces cerevisiae.

1984 ◽  
Vol 4 (1) ◽  
pp. 142-150 ◽  
Author(s):  
A Percival-Smith ◽  
J Segall
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Dna Sequences ◽  
Vegetative Growth ◽  
Cdna Probe ◽  
Cell Types ◽  
Sporulation Medium ◽  
Alpha Cells ◽  
Yeast Saccharomyces Cerevisiae ◽  
Dna Library ◽  
Vector Pbr322

A differential hybridization screen has been used to identify genes cloned from the yeast Saccharomyces cerevisiae that are expressed preferentially during sporulation. Duplicate copies of a partial Sau3A yeast DNA library prepared in the vector pBR322 were hybridized with radioactive cDNA probes representing the mRNA populations of sporulating a alpha cells and asporogenous alpha alpha cells at various times after transfer to sporulation medium. Thirty-eight clones showed an enhanced hybridization signal with the a alpha sporulation probe relative to the alpha alpha control cDNA probe. A comparison of the array of fragments produced by restriction endonuclease digestion of these plasmids suggested that 15 different sequences had been cloned. An RNA blot analysis using these cloned DNAs to probe RNAs purified from aa, a alpha, and alpha alpha cells harvested either during vegetative growth or at 10 h after transfer to sporulation medium indicated that 14 different sporulation-specific genes had been identified. Transcripts complementary to these genes are present only in a alpha cells after transfer to sporulation medium. Three of these clones contain two sporulation-specific genes. Three genes have been identified that are expressed in all cell types during vegetative growth and only in a alpha cells in sporulation medium.

Courtship in Saccharomyces cerevisiae: an early cell-cell interaction during mating

1990 ◽  
Vol 10 (5) ◽  
pp. 2202-2213
Author(s):  
C L Jackson ◽  
L H Hartwell
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Interaction ◽  
Yeast Cells ◽  
Induced Response ◽  
Specific Gene ◽  
Gene Products ◽  
Alpha Cells ◽  
Wild Type ◽  
Opposite Mating Type ◽  
Mating Partner

During conjugation in Saccharomyces cerevisiae, two cells of opposite mating type (MATa and MAT alpha) fuse to form a diploid zygote. Conjugation requires that each cell locate an appropriate mating partner. To investigate how yeast cells select a mating partner, we developed a competition mating assay in which wild-type MAT alpha cells have a choice of two MATa cell mating partners. We first demonstrated that sterile MAT alpha 1 cells (expressing no a- or alpha-specific gene products) do not compete with fertile MATa cells in the assay; hence, wild-type MATa and MAT alpha cells can efficiently locate an appropriate mating partner. Second, we showed that a MATa strain need not be fertile to compete with a fertile MATa strain in the assay. This result defines an early step in conjugation, which we term courtship. We showed that the ability to agglutinate is not necessary in MATa cells for courtship but that production of a-pheromone and response to alpha-pheromone are necessary. Thus, MATa cells must not only transmit but must also receive and then respond to information for effective courtship; hence, there is a "conversation" between the courting cells. We showed that the only alpha-pheromone-induced response necessary in MATa cells for courtship is production of a-pheromone. In all cases tested, a strain producing a higher level of a-pheromone was more proficient in courtship than one producing a lower level. We propose that during courtship, a MAT alpha cell selects the adjacent MATa cell producing the highest level of a-pheromone.

The SPS4 gene of Saccharomyces cerevisiae encodes a major sporulation-specific mRNA

1986 ◽  
Vol 6 (12) ◽  
pp. 4478-4485
Author(s):  
A T Garber ◽  
J Segall
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Polyacrylamide Gel Electrophoresis ◽  
Specific Protein ◽  
Polyacrylamide Gel ◽  
In Vitro Translation ◽  
Specific Gene ◽  
Alpha Cells ◽  
Two Dimensional ◽  
Isoelectric Ph

The SPS4 gene of Saccharomyces cerevisiae, a sporulation-specific gene identified previously in a differential hybridization screen of a genomic yeast DNA library, has been characterized further. The protein encoded by this gene was inferred from its nucleotide sequence to be 38,600 daltons with an isoelectric pH of 8.2. Consistent with this, two-dimensional polyacrylamide gel electrophoresis of the in vitro translation products of RNA purified by hybridization with the cloned SPS4 DNA indicated that the SPS4 gene product is a 39-kilodalton, basic protein. This protein was found to be identical in size and charge to a major, sporulation-specific protein identified in a two-dimensional polyacrylamide gel electrophoretic comparison of the in vitro translation products of total RNA from sporulating MATa/MAT alpha cells and asporogenous MAT alpha/MAT alpha cells. A MATa/MAT alpha strain homozygous for a partial deletion of the SPS4 gene appeared, however, to be unaffected in its ability to form viable ascospores.

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