scholarly journals SAM2 encodes the second methionine S-adenosyl transferase in Saccharomyces cerevisiae: physiology and regulation of both enzymes.

1988 ◽  
Vol 8 (12) ◽  
pp. 5132-5139 ◽  
Author(s):  
D Thomas ◽  
R Rothstein ◽  
N Rosenberg ◽  
Y Surdin-Kerjan
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Gene Disruption ◽  
Double Mutant ◽  
State Level ◽  
Functional Complementation ◽  
The Other ◽  
Steady State Level ◽  
Duplicated Genes ◽  
Double Mutant Strain ◽  
Adomet Synthetase

In Saccharomyces cerevisiae the SAM1 and SAM2 genes encode two distinct forms of S-adenosylmethionine (AdoMet) synthetase. In a previous study we cloned and sequenced the SAM1 gene (D. Thomas and Y. Surdin-Kerjan, J. Biol. Chem. 262:16704-16709, 1987). In this work, the SAM2 gene was isolated by functional complementation of a yeast double-mutant strain, and its identity was ascertained by gene disruption. It has been sequenced and compared with the SAM1 gene. The degree of homology found between the two genes shows that SAM1 and SAM2 are duplicated genes. Using strains disrupted in one or the other SAM gene, we have studied the regulation of their expression by measuring the steady-state level of mRNA after growth under different conditions. The results show that the expression of the two SAM genes is regulated differently, SAM2 being induced by the presence of excess methionine in the growth medium and SAM1 being repressed under the same conditions. The level of mRNA in the parental strain shows that it is not the sum of the levels found in the two disrupted strains. This raises the question of how the two AdoMet synthetases in S. cerevisiae interact to control AdoMet synthesis.

SAM2 encodes the second methionine S-adenosyl transferase in Saccharomyces cerevisiae: physiology and regulation of both enzymes

1988 ◽  
Vol 8 (12) ◽  
pp. 5132-5139
Author(s):  
D Thomas ◽  
R Rothstein ◽  
N Rosenberg ◽  
Y Surdin-Kerjan
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Gene Disruption ◽  
Double Mutant ◽  
State Level ◽  
Functional Complementation ◽  
The Other ◽  
Steady State Level ◽  
Duplicated Genes ◽  
Double Mutant Strain ◽  
Adomet Synthetase

In Saccharomyces cerevisiae the SAM1 and SAM2 genes encode two distinct forms of S-adenosylmethionine (AdoMet) synthetase. In a previous study we cloned and sequenced the SAM1 gene (D. Thomas and Y. Surdin-Kerjan, J. Biol. Chem. 262:16704-16709, 1987). In this work, the SAM2 gene was isolated by functional complementation of a yeast double-mutant strain, and its identity was ascertained by gene disruption. It has been sequenced and compared with the SAM1 gene. The degree of homology found between the two genes shows that SAM1 and SAM2 are duplicated genes. Using strains disrupted in one or the other SAM gene, we have studied the regulation of their expression by measuring the steady-state level of mRNA after growth under different conditions. The results show that the expression of the two SAM genes is regulated differently, SAM2 being induced by the presence of excess methionine in the growth medium and SAM1 being repressed under the same conditions. The level of mRNA in the parental strain shows that it is not the sum of the levels found in the two disrupted strains. This raises the question of how the two AdoMet synthetases in S. cerevisiae interact to control AdoMet synthesis.

SPT10 and SPT21 are required for transcription of particular histone genes in Saccharomyces cerevisiae

1994 ◽  
Vol 14 (8) ◽  
pp. 5223-5228
Author(s):  
C Dollard ◽  
S L Ricupero-Hovasse ◽  
G Natsoulis ◽  
J D Boeke ◽  
F Winston
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Differential Expression ◽  
Double Mutant ◽  
The Other ◽  
Histone Genes ◽  
Related Gene ◽  
Histone Proteins ◽  
Histone Locus

The Saccharomyces cerevisiae genome contains four loci that encode histone proteins. Two of these loci, HTA1-HTB1 and HTA2-HTB2, each encode histones H2A and H2B. The other two loci, HHT1-HHF1 and HHT2-HHF2, each encode histones H3 and H4. Because of their redundancy, deletion of any one histone locus does not cause lethality. Previous experiments demonstrated that mutations at one histone locus, HTA1-HTB1, do cause lethality when in conjunction with mutations in the SPT10 gene. SPT10 has been shown to be required for normal levels of transcription of several genes in S. cerevisiae. Motivated by this double-mutant lethality, we have now investigated the interactions of mutations in SPT10 and in a functionally related gene, SPT21, with mutations at each of the four histone loci. These experiments have demonstrated that both SPT10 and SPT21 are required for transcription at two particular histone loci, HTA2-HTB2 and HHF2-HHT2, but not at the other two histone loci. These results suggest that under some conditions, S. cerevisiae may control the level of histone proteins by differential expression of its histone genes.

scholarly journals Post-translational processing of urea amidolyase in Saccharomyces cerevisiae.

1982 ◽  
Vol 2 (7) ◽  
pp. 800-804 ◽  
Author(s):  
R A Sumrada ◽  
G Chisholm ◽  
T G Cooper
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Steady State ◽  
State Level ◽  
Steady State Level ◽  
Prosthetic Group ◽  
Apparent Paradox ◽  
Multifunctional Protein ◽  
Group A ◽  
Time Required ◽  
Sequential Induction

Urea amidolyase catalyzes the two reactions (urea carboxylase and a allophanate hydrolase) associated with urea degradation in Saccharomyces cerevisiae. Past work has shown that both reactions are catalyzed by a 204-kilodalton, multifunctional protein. In view of these observations, it was surprising to find that on induction at 22 degrees C, approximately 2 to 6 min elapsed between the appearance of allophanate hydrolase and urea carboxylase activities. In search of an explanation for this apparent paradox, we determined whether or not a detectable period of time elapsed between the appearance of allophanate hydrolase activity and activation of the urea carboxylase domain by the addition of biotin. We found that a significant portion of the protein produced immediately after the onset of induction lacked the prosthetic group. A steady-state level of biotin-free enzyme was reached 16 min after induction and persisted indefinitely thereafter. These data are consistent with the suggestion that sequential induction of allophanate hydrolase and urea carboxylase activities results from the time required to covalently bind biotin to the latter domain of the protein.

scholarly journals Regulation of CDC9, the Saccharomyces cerevisiae gene that encodes DNA ligase.

1985 ◽  
Vol 5 (1) ◽  
pp. 226-235 ◽  
Author(s):  
T A Peterson ◽  
L Prakash ◽  
S Prakash ◽  
M A Osley ◽  
S I Reed
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Cycle ◽  
Steady State ◽  
Uv Light ◽  
State Level ◽  
S Phase ◽  
Dna Ligase ◽  
Mrna Levels ◽  
Steady State Level ◽  
High Level

We have cloned CDC9, the structural gene for Saccharomyces cerevisiae DNA ligase, and investigated its transcriptional regulation both as a function of cell cycle stage and after UV irradiation. The steady-state level of DNA ligase mRNA increases at least fourfold in late G1, after the completion of start but before S phase. This high level of CDC9 mRNA then decays with an apparent half-life of ca. 20 min and remains at a low basal level throughout the rest of the cell cycle. The accumulation of CDC9 mRNA in late G1 is dependent upon the completion of start but not the CDC7 and CDC8 functions. Exposure of cells to UV light elicits an eightfold increase in DNA ligase mRNA levels.

scholarly journals Two Novel Techniques for Determination of Polysaccharide Cross-Links Show that Crh1p and Crh2p Attach Chitin to both β(1-6)- and β(1-3)Glucan in the Saccharomyces cerevisiae Cell Wall

2009 ◽  
Vol 8 (11) ◽  
pp. 1626-1636 ◽  
Author(s):  
Enrico Cabib
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Wall ◽  
Acetic Acid ◽  
Yeast Cell ◽  
Cell Walls ◽  
Double Mutant ◽  
The Other ◽  
Cross Links

ABSTRACT Previous work, using solubilization of yeast cell walls by carboxymethylation, before or after digestion with β(1-3)- or β(1-6)glucanase, followed by size chromatography, showed that the transglycosylases Crh1p and Crh2p/Utr2p were redundantly required for the attachment of chitin to β(1-6)glucan. With this technique, crh1Δ crh2Δ mutants still appeared to contain a substantial percentage of chitin linked to β(1-3)glucan. Two novel procedures have now been developed for the analysis of polysaccharide cross-links in the cell wall. One is based on the affinity of curdlan, a β(1-3)glucan, for β(1-3)glucan chains in carboxymethylated cell walls. The other consists of in situ deacetylation of cell wall chitin, generating chitosan, which can be extracted with acetic acid, either directly (free chitosan) or after digestion with different glucanases (bound chitosan). Both methodologies indicated that all of the chitin in crh1Δ crh2Δ strains is free. Reexamination of the previously used procedure revealed that the β(1-3)glucanase preparation used (zymolyase) is contaminated with a small amount of endochitinase, which caused erroneous results with the double mutant. After removing the chitinase from the zymolyase, all three procedures gave coincident results. Therefore, Crh1p and Crh2p catalyze the transfer of chitin to both β(1-3)- and β(1-6)glucan, and the biosynthetic mechanism for all chitin cross-links in the cell wall has been established.

scholarly journals Transcriptional regulation of SSA3, an HSP70 gene from Saccharomyces cerevisiae.

1990 ◽  
Vol 10 (6) ◽  
pp. 3262-3267 ◽  
Author(s):  
W R Boorstein ◽  
E A Craig
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Heat Shock ◽  
Double Mutant ◽  
Optimal Growth ◽  
Growth Conditions ◽  
Hsp70 Gene ◽  
Base Pairs ◽  
Double Mutant Strain ◽  
Low Levels ◽  
Necessary And Sufficient

The SSA3 gene of Saccharomyces cerevisiae, a member of the HSP70 multigene family, is expressed at low levels under optimal growth conditions and is dramatically induced in response to heat shock. Sequences coinciding with two overlapping heat shock elements, located 156 base pairs upstream of the transcribed region, were necessary and sufficient for regulation of heat induction. The SSA3 promoter was also activated in an ssa1ssa2 double-mutant strain. This increase in the expression of SSA3 was mediated via the same upstream activating sequences that activated transcription in response to heat shock.

Regulation of CDC9, the Saccharomyces cerevisiae gene that encodes DNA ligase

1985 ◽  
Vol 5 (1) ◽  
pp. 226-235
Author(s):  
T A Peterson ◽  
L Prakash ◽  
S Prakash ◽  
M A Osley ◽  
S I Reed
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Cycle ◽  
Steady State ◽  
Uv Light ◽  
State Level ◽  
S Phase ◽  
Dna Ligase ◽  
Mrna Levels ◽  
Steady State Level ◽  
High Level

We have cloned CDC9, the structural gene for Saccharomyces cerevisiae DNA ligase, and investigated its transcriptional regulation both as a function of cell cycle stage and after UV irradiation. The steady-state level of DNA ligase mRNA increases at least fourfold in late G1, after the completion of start but before S phase. This high level of CDC9 mRNA then decays with an apparent half-life of ca. 20 min and remains at a low basal level throughout the rest of the cell cycle. The accumulation of CDC9 mRNA in late G1 is dependent upon the completion of start but not the CDC7 and CDC8 functions. Exposure of cells to UV light elicits an eightfold increase in DNA ligase mRNA levels.

Post-translational processing of urea amidolyase in Saccharomyces cerevisiae

1982 ◽  
Vol 2 (7) ◽  
pp. 800-804
Author(s):  
R A Sumrada ◽  
G Chisholm ◽  
T G Cooper
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Steady State ◽  
State Level ◽  
Steady State Level ◽  
Prosthetic Group ◽  
Apparent Paradox ◽  
Multifunctional Protein ◽  
Group A ◽  
Time Required ◽  
Sequential Induction

Urea amidolyase catalyzes the two reactions (urea carboxylase and a allophanate hydrolase) associated with urea degradation in Saccharomyces cerevisiae. Past work has shown that both reactions are catalyzed by a 204-kilodalton, multifunctional protein. In view of these observations, it was surprising to find that on induction at 22 degrees C, approximately 2 to 6 min elapsed between the appearance of allophanate hydrolase and urea carboxylase activities. In search of an explanation for this apparent paradox, we determined whether or not a detectable period of time elapsed between the appearance of allophanate hydrolase activity and activation of the urea carboxylase domain by the addition of biotin. We found that a significant portion of the protein produced immediately after the onset of induction lacked the prosthetic group. A steady-state level of biotin-free enzyme was reached 16 min after induction and persisted indefinitely thereafter. These data are consistent with the suggestion that sequential induction of allophanate hydrolase and urea carboxylase activities results from the time required to covalently bind biotin to the latter domain of the protein.

scholarly journals SPT10 and SPT21 are required for transcription of particular histone genes in Saccharomyces cerevisiae.

1994 ◽  
Vol 14 (8) ◽  
pp. 5223-5228 ◽  
Author(s):  
C Dollard ◽  
S L Ricupero-Hovasse ◽  
G Natsoulis ◽  
J D Boeke ◽  
F Winston
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Differential Expression ◽  
Double Mutant ◽  
The Other ◽  
Histone Genes ◽  
Related Gene ◽  
Histone Proteins ◽  
Histone Locus

The Saccharomyces cerevisiae genome contains four loci that encode histone proteins. Two of these loci, HTA1-HTB1 and HTA2-HTB2, each encode histones H2A and H2B. The other two loci, HHT1-HHF1 and HHT2-HHF2, each encode histones H3 and H4. Because of their redundancy, deletion of any one histone locus does not cause lethality. Previous experiments demonstrated that mutations at one histone locus, HTA1-HTB1, do cause lethality when in conjunction with mutations in the SPT10 gene. SPT10 has been shown to be required for normal levels of transcription of several genes in S. cerevisiae. Motivated by this double-mutant lethality, we have now investigated the interactions of mutations in SPT10 and in a functionally related gene, SPT21, with mutations at each of the four histone loci. These experiments have demonstrated that both SPT10 and SPT21 are required for transcription at two particular histone loci, HTA2-HTB2 and HHF2-HHT2, but not at the other two histone loci. These results suggest that under some conditions, S. cerevisiae may control the level of histone proteins by differential expression of its histone genes.

scholarly journals Hormonal regulation of collagenolysis in uterine cervical fibroblasts. Modulation of synthesis of procollagenase, prostromelysin and tissue inhibitor of metalloproteinases (TIMP) by progesterone and oestradiol-17 β

1991 ◽  
Vol 275 (3) ◽  
pp. 645-650 ◽  
Author(s):  
T Sato ◽  
A Ito ◽  
Y Mori ◽  
K Yamashita ◽  
T Hayakawa ◽  
...  
Keyword(s):  
Steady State ◽  
Hormonal Regulation ◽  
Culture Media ◽  
Interleukin 1 ◽  
State Level ◽  
The Other ◽  
Steady State Level ◽  
Tissue Inhibitor Of Metalloproteinases ◽  
Tissue Inhibitor ◽  
Steady State Levels

Rabbit uterine cervical fibroblasts produced a large amount of matrix metalloproteinases (MMPs) such as collagenase (MMP-1) and stromelysin (MMP-3) and a small relatively amount of tissue inhibitor of metalloproteinases (TIMP). When cells were treated with progesterone or oestradiol-17 beta, both steroids concurrently decreased the level of procollagenase and prostromelysin in the culture media and the steady-state levels of the respective mRNAs. On the other hand, the level of TIMP in the culture media and the steady-state level of its mRNA were simultaneously increased by these steroids. Similarly, the suppression of production of MMPs and the augmentation of TIMP production by both steroids were observed with interleukin 1 (IL-1)-treated cells, but the action of progesterone was more effective than that of oestradiol-17 beta in the IL-1-untreated and -treated cells. These results suggest that collagenolysis in uterine cervical fibroblasts is negatively regulated by steroid hormones via the acceleration of TIMP production and the suppression of synthesis of MMPs at the pretranslational level.

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