scholarly journals Modulation of chromatin structure associated with derepression of the acid phosphatase gene of Saccharomyces cerevisiae.

1983 ◽  
Vol 258 (11) ◽  
pp. 7223-7227
Author(s):  
L W Bergman ◽  
R A Kramer
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Acid Phosphatase ◽  
Chromatin Structure ◽  
Acid Phosphatase Gene

scholarly journals Signal peptide specificity in posttranslational processing of the plant protein phaseolin in Saccharomyces cerevisiae.

1987 ◽  
Vol 7 (1) ◽  
pp. 121-128 ◽  
Author(s):  
J H Cramer ◽  
K Lea ◽  
M D Schaber ◽  
R A Kramer
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Acid Phosphatase ◽  
Signal Peptide ◽  
Regulatory Region ◽  
Cellular Protein ◽  
Proteolytic Processing ◽  
Coding Region ◽  
Molecular Weights ◽  
Amino Terminal ◽  
Acid Phosphatase Gene

We linked the cDNA coding region for the bean storage protein phaseolin to the promoter and regulatory region of the Saccharomyces cerevisiae repressible acid phosphatase gene (PHO5) in multicopy expression plasmids. Yeast transformants containing these plasmids expressed phaseolin at levels up to 3% of the total soluble cellular protein. Phaseolin polypeptides in S. cerevisiae were glycosylated, and their molecular weights suggested that the signal peptide had been processed. We also constructed a series of plasmids in which the phaseolin signal-peptide-coding region was either removed or replaced with increasing amounts of the amino-terminal coding region for acid phosphatase. Phaseolin polypeptides with no signal peptide were not posttranslationally modified in S. cerevisiae. Partial or complete substitution of the phaseolin signal peptide with that from acid phosphatase dramatically inhibited both signal peptide processing and glycosylation, suggesting that some specific feature of the phaseolin signal amino acid sequence was required for these modifications to occur. Larger hybrid proteins that included approximately one-half of the acid phosphatase sequence linked to the amino terminus of the mature phaseolin polypeptide did undergo proteolytic processing and glycosylation. However, these polypeptides were cleaved at several sites that are not normally used in the unaltered acid phosphatase protein.

scholarly journals Structure of the transcriptionally repressed phosphate-repressible acid phosphatase gene (PHO5) of Saccharomyces cerevisiae.

1986 ◽  
Vol 6 (1) ◽  
pp. 38-46 ◽  
Author(s):  
L W Bergman ◽  
M C Stranathan ◽  
L H Preis
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Acid Phosphatase ◽  
Copy Number ◽  
Regulatory Control ◽  
Gene Copy ◽  
Growth Media ◽  
Regulatory Sequences ◽  
Mrna Levels ◽  
Acid Phosphatase Gene ◽  
Negative Supercoils

We developed a high-copy-number plasmid system containing the entire structural and regulatory sequences of the phosphate-repressible acid phosphatase (PHO5) gene and the TRP1/ARS1 replicator sequences of the yeast Saccharomyces cerevisiae to investigate the mechanism of repression-derepression of transcription. The resulting plasmid was used to transform either wild-type cells or a number of strains which contain mutations in various trans-acting regulatory loci for the production of acid phosphatase. Results of analysis of mRNA levels isolated from the transformed strains grown under repressed or derepressed conditions suggested that normal transcriptional regulation of the gene persisted, although gene copy number was significantly increased. Analysis of changes in linking number (i.e., the number of negative supercoils) of the plasmid isolated under repressed and derepressed growth conditions revealed that the transcriptionally inactive plasmid contained approximately three more negative supercoils than the transcriptionally active plasmid. This difference in topological state was similarly seen in a plasmid containing a sequence-related acid phosphatase gene (PHO11) under the same regulatory control system, but it was not seen in plasmids isolated from some strains containing mutations which caused either fully constitutive or nonderepressible production of acid phosphatase. Finally, analysis of the nucleosome positioning along the inactive gene sequence revealed that an abnormally broad internucleosomal spacer is present in a region presumed to function in the regulation of transcription by the level of Pi in the growth media.

Signal peptide specificity in posttranslational processing of the plant protein phaseolin in Saccharomyces cerevisiae

1987 ◽  
Vol 7 (1) ◽  
pp. 121-128
Author(s):  
J H Cramer ◽  
K Lea ◽  
M D Schaber ◽  
R A Kramer
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Acid Phosphatase ◽  
Signal Peptide ◽  
Regulatory Region ◽  
Cellular Protein ◽  
Proteolytic Processing ◽  
Coding Region ◽  
Molecular Weights ◽  
Amino Terminal ◽  
Acid Phosphatase Gene

We linked the cDNA coding region for the bean storage protein phaseolin to the promoter and regulatory region of the Saccharomyces cerevisiae repressible acid phosphatase gene (PHO5) in multicopy expression plasmids. Yeast transformants containing these plasmids expressed phaseolin at levels up to 3% of the total soluble cellular protein. Phaseolin polypeptides in S. cerevisiae were glycosylated, and their molecular weights suggested that the signal peptide had been processed. We also constructed a series of plasmids in which the phaseolin signal-peptide-coding region was either removed or replaced with increasing amounts of the amino-terminal coding region for acid phosphatase. Phaseolin polypeptides with no signal peptide were not posttranslationally modified in S. cerevisiae. Partial or complete substitution of the phaseolin signal peptide with that from acid phosphatase dramatically inhibited both signal peptide processing and glycosylation, suggesting that some specific feature of the phaseolin signal amino acid sequence was required for these modifications to occur. Larger hybrid proteins that included approximately one-half of the acid phosphatase sequence linked to the amino terminus of the mature phaseolin polypeptide did undergo proteolytic processing and glycosylation. However, these polypeptides were cleaved at several sites that are not normally used in the unaltered acid phosphatase protein.

Structure of the transcriptionally repressed phosphate-repressible acid phosphatase gene (PHO5) of Saccharomyces cerevisiae

1986 ◽  
Vol 6 (1) ◽  
pp. 38-46
Author(s):  
L W Bergman ◽  
M C Stranathan ◽  
L H Preis
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Acid Phosphatase ◽  
Copy Number ◽  
Regulatory Control ◽  
Gene Copy ◽  
Growth Media ◽  
Regulatory Sequences ◽  
Mrna Levels ◽  
Acid Phosphatase Gene ◽  
Negative Supercoils

We developed a high-copy-number plasmid system containing the entire structural and regulatory sequences of the phosphate-repressible acid phosphatase (PHO5) gene and the TRP1/ARS1 replicator sequences of the yeast Saccharomyces cerevisiae to investigate the mechanism of repression-derepression of transcription. The resulting plasmid was used to transform either wild-type cells or a number of strains which contain mutations in various trans-acting regulatory loci for the production of acid phosphatase. Results of analysis of mRNA levels isolated from the transformed strains grown under repressed or derepressed conditions suggested that normal transcriptional regulation of the gene persisted, although gene copy number was significantly increased. Analysis of changes in linking number (i.e., the number of negative supercoils) of the plasmid isolated under repressed and derepressed growth conditions revealed that the transcriptionally inactive plasmid contained approximately three more negative supercoils than the transcriptionally active plasmid. This difference in topological state was similarly seen in a plasmid containing a sequence-related acid phosphatase gene (PHO11) under the same regulatory control system, but it was not seen in plasmids isolated from some strains containing mutations which caused either fully constitutive or nonderepressible production of acid phosphatase. Finally, analysis of the nucleosome positioning along the inactive gene sequence revealed that an abnormally broad internucleosomal spacer is present in a region presumed to function in the regulation of transcription by the level of Pi in the growth media.

Regulation of repressible acid phosphatase gene transcription in Saccharomyces cerevisiae

1985 ◽  
Vol 5 (8) ◽  
pp. 2131-2141
Author(s):  
J M Lemire ◽  
T Willcocks ◽  
H O Halvorson ◽  
K A Bostian
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Acid Phosphatase ◽  
Gene Transcription ◽  
Transcriptional Activation ◽  
Regulatory Gene ◽  
Genetic System ◽  
Yeast Genome ◽  
Mrna Synthesis ◽  
Protein Factor ◽  
Acid Phosphatase Gene

We examined the genetic system responsible for transcriptional regulation of repressible acid phosphatase (APase; orthophosphoric-monoester phosphohydrolase [acid optimum, EC 3.1.3.2]) in Saccharomyces cerevisiae at the molecular level by analysis of previously isolated and genetically well-defined regulatory gene mutants known to affect APase expression. These mutants identify numerous positive- (PHO4, PHO2, PHO81) and negative-acting (PHO80, PHO85) regulatory loci dispersed throughout the yeast genome. We showed that the interplay of these positive and negative regulatory genes occurs before or during APase gene transcription and that their functions are all indispensible for normal regulation of mRNA synthesis. Biochemical evidence suggests that the regulatory gene products they encode are expressed constitutively. More detailed investigation of APase synthesis is a conditional PHO80(Ts) mutant indicated that neither PHO4 nor any other protein factor necessary for APase mRNA synthesis is transcriptionally regulated by PHO80. Moreover, in the absence of PHO80, the corepressor, presumed to be a metabolite of Pi, did not inhibit their function in the transcriptional activation of APase.

Physiological control of repressible acid phosphatase gene transcripts in Saccharomyces cerevisiae

1983 ◽  
Vol 3 (5) ◽  
pp. 839-853
Author(s):  
K A Bostian ◽  
J M Lemire ◽  
H O Halvorson
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Acid Phosphatase ◽  
Accumulation Rate ◽  
Mrna Levels ◽  
Phosphorus Metabolism ◽  
Physiological Control ◽  
Phosphatase Regulation ◽  
Gene Transcripts ◽  
Acid Phosphatase Gene ◽  
Polyphosphate Degradation

We have examined the regulation of repressible acid phosphatase (APase; orthophosphoric-monoester phosphohydrolase [acid optimum], EC 3.1.3.2) in Saccharomyces cerevisiae at the physiological and molecular levels, through a series of repression and derepression experiments. We demonstrated that APase synthesis is tightly regulated throughout the growth phase and is influenced by exogenous and endogenous Pi pools. During growth in a nonlimiting Pi medium, APase is repressed. When external Pi becomes limiting, there is a biphasic appearance of APase mRNA and enzyme. Our data on APase mRNA half-lives and on the flux of intracellular Pi and polyphosphate during derepression are consistent with a mechanism of transcriptional autoregulation for the biphasic appearance of APase mRNA. Accordingly, preculture concentrations of Pi control the level of corepressor generated from intracellular polyphosphate degradation. When cells are fully derepressed, APase mRNA levels are constant, and the maximal linear accumulation rate of APase is observed. A scheme to integrate phosphorus metabolism and phosphatase regulation in S. cerevisiae is proposed.

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