scholarly journals Sporulation and rna2 lower ribosomal protein mRNA levels by different mechanisms in Saccharomyces cerevisiae.

1982 ◽  
Vol 2 (10) ◽  
pp. 1199-1204 ◽  
Author(s):  
E Kraig ◽  
J E Haber ◽  
M Rosbash
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Ribosomal Protein ◽  
Ribosomal Proteins ◽  
Relative Rate ◽  
Synthesis Rate ◽  
Temperature Sensitive ◽  
Restrictive Temperature ◽  
Mrna Levels ◽  
Ribosomal Protein Genes ◽  
Mrna Metabolism

In Saccharomyces cerevisiae, the levels of ribosomal protein mRNAs are regulated coordinately. Vegetative strains carrying the temperature-sensitive rna2 mutation exhibit a dramatic decrease in the levels of most ribosomal protein mRNAs at the restrictive temperature. Similarly, in wild-type cells induced to sporulate by nitrogen starvation, there is a fivefold reduction in the relative synthesis rate of ribosomal proteins. Using Northern gel analysis and cloned ribosomal protein genes, we compared the way in which ribosomal protein mRNA is affected under these two conditions. In vegetative rna2 cells, incubation at 34 degrees C led to the disappearance of ribosomal protein mRNAs and the accumulation of higher-molecular-weight precursor RNAs. A different phenotype was observed during sporulation. Although sporulating conditions led to a significant reduction in the relative abundance of ribosomal protein mRNA, there was no detectable accumulation of precursor RNAs even in rna2/rna2 diploids at 34 degrees C. A suppressor of rna2 and of other rna mutations, SRN1, at least partially relieved the block in the splicing of the ribosomal protein 51 intron in vegetative rna2 cells but did not detectably affect the level of ribosomal protein mRNA in sporulating cells. We concluded that the rna2 mutation and sporulation conditions affected ribosomal protein mRNA metabolism in two quite different ways. In vegetative cells the mutant rna2 effected a block which occurred primarily in post-transcriptional processing, whereas in sporulating cells the ribosomal protein mRNA levels were decreased by some other mechanism, presumably a change in the relative rate of transcription or mRNA turnover. Furthermore, the data suggest that the mutation rna2 has no additional effect on ribosomal protein mRNA metabolism in sporulating cells.

Sporulation and rna2 lower ribosomal protein mRNA levels by different mechanisms in Saccharomyces cerevisiae

1982 ◽  
Vol 2 (10) ◽  
pp. 1199-1204
Author(s):  
E Kraig ◽  
J E Haber ◽  
M Rosbash
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Ribosomal Protein ◽  
Ribosomal Proteins ◽  
Relative Rate ◽  
Synthesis Rate ◽  
Temperature Sensitive ◽  
Restrictive Temperature ◽  
Mrna Levels ◽  
Ribosomal Protein Genes ◽  
Mrna Metabolism

In Saccharomyces cerevisiae, the levels of ribosomal protein mRNAs are regulated coordinately. Vegetative strains carrying the temperature-sensitive rna2 mutation exhibit a dramatic decrease in the levels of most ribosomal protein mRNAs at the restrictive temperature. Similarly, in wild-type cells induced to sporulate by nitrogen starvation, there is a fivefold reduction in the relative synthesis rate of ribosomal proteins. Using Northern gel analysis and cloned ribosomal protein genes, we compared the way in which ribosomal protein mRNA is affected under these two conditions. In vegetative rna2 cells, incubation at 34 degrees C led to the disappearance of ribosomal protein mRNAs and the accumulation of higher-molecular-weight precursor RNAs. A different phenotype was observed during sporulation. Although sporulating conditions led to a significant reduction in the relative abundance of ribosomal protein mRNA, there was no detectable accumulation of precursor RNAs even in rna2/rna2 diploids at 34 degrees C. A suppressor of rna2 and of other rna mutations, SRN1, at least partially relieved the block in the splicing of the ribosomal protein 51 intron in vegetative rna2 cells but did not detectably affect the level of ribosomal protein mRNA in sporulating cells. We concluded that the rna2 mutation and sporulation conditions affected ribosomal protein mRNA metabolism in two quite different ways. In vegetative cells the mutant rna2 effected a block which occurred primarily in post-transcriptional processing, whereas in sporulating cells the ribosomal protein mRNA levels were decreased by some other mechanism, presumably a change in the relative rate of transcription or mRNA turnover. Furthermore, the data suggest that the mutation rna2 has no additional effect on ribosomal protein mRNA metabolism in sporulating cells.

Mild temperature shock alters the transcription of a discrete class of Saccharomyces cerevisiae genes

1983 ◽  
Vol 3 (3) ◽  
pp. 457-465
Author(s):  
C H Kim ◽  
J R Warner
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Ribosomal Protein ◽  
Ribosomal Proteins ◽  
Temperature Shift ◽  
Restrictive Temperature ◽  
Ribosomal Protein Genes ◽  
Wild Type ◽  
Temperature Shock ◽  
Mild Temperature ◽  
Mutant Cells

In Saccharomyces cerevisiae the synthesis of ribosomal proteins declines temporarily after a culture has been subjected to a mild temperature shock, i.e., a shift from 23 to 36 degrees C, each of which support growth. Using cloned genes for several S. cerevisiae ribosomal proteins, we found that the changes in the synthesis of ribosomal proteins parallel the changes in the concentration of mRNA of each. The disappearance and reappearance of the mRNA is due to a brief but severe inhibition of the transcription of each of the ribosomal protein genes, although the total transcription of mRNA in the cells is relatively unaffected by the temperature shock. The precisely coordinated response of these genes, which are scattered throughout the genome, suggests that either they or the enzyme which transcribes them has unique properties. In certain S. cerevisiae mutants, the synthesis of ribosomal proteins never recovers from a temperature shift. Yet both the decline and the resumption of transcription of these genes during the 30 min after the temperature shift are indistinguishable from those in wild-type cells. The failure of the mutant cells to grow at the restrictive temperature appears to be due to their inability to process the RNA transcribed from genes which have introns (Rosbash et al., Cell 24:679-686, 1981), a large proportion of which appear to be ribosomal protein genes.

A suppressor of temperature-sensitive rna mutations that affect mRNA metabolism in Saccharomyces cerevisiae

1982 ◽  
Vol 2 (5) ◽  
pp. 571-577
Author(s):  
N J Pearson ◽  
P C Thorburn ◽  
J E Haber
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Temperature Sensitive ◽  
Mrna Levels ◽  
Ribosomal Protein Genes ◽  
Mrna Synthesis ◽  
Yeast Saccharomyces Cerevisiae ◽  
Double Mutation ◽  
Mrna Metabolism ◽  
Intervening Sequences ◽  
Dominant Suppressor

We have isolated a dominant suppressor of rna mutation (SRN1) that relieves the temperature-sensitive inhibition of mRNA synthesis of ribosomal protein genes in the yeast Saccharomyces cerevisiae. The suppressor was selected for its ability to alleviate simultaneously the temperature-sensitive growth phenotypes of rna2 and rna6. Several independently isolated suppressors appeared to be recessive lethal mutations. One suppressor, SRN1, was recovered as viable in haploid strains. SRN1 can suppress rna2, rna3, rna4, rna5, rna6, and rna8 singly or in pairs, although some combinations of rna mutations are less well suppressed than others. The suppressor allows strains with rna mutations to grow at 34 degrees C but is unable to suppress at 37 degrees C; however, SRN1 does not, by itself, prevent growth at 37 degrees C. In addition, SRN1 suppresses the rna1 mutation which affects general mRNA levels and also leads to the accumulation of precursor tRNA for those tRNAs that have intervening sequences. SRN1 can suppress the rna1 mutation as well as the rna1 rna2 double mutation at 34 degrees C. The suppressor does not affect the temperature-sensitive growth of two unrelated temperature-sensitive mutations, cdc4 and cdc7.

scholarly journals Mild temperature shock alters the transcription of a discrete class of Saccharomyces cerevisiae genes.

1983 ◽  
Vol 3 (3) ◽  
pp. 457-465 ◽  
Author(s):  
C H Kim ◽  
J R Warner
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Ribosomal Protein ◽  
Ribosomal Proteins ◽  
Temperature Shift ◽  
Restrictive Temperature ◽  
Ribosomal Protein Genes ◽  
Wild Type ◽  
Temperature Shock ◽  
Mild Temperature ◽  
Mutant Cells

In Saccharomyces cerevisiae the synthesis of ribosomal proteins declines temporarily after a culture has been subjected to a mild temperature shock, i.e., a shift from 23 to 36 degrees C, each of which support growth. Using cloned genes for several S. cerevisiae ribosomal proteins, we found that the changes in the synthesis of ribosomal proteins parallel the changes in the concentration of mRNA of each. The disappearance and reappearance of the mRNA is due to a brief but severe inhibition of the transcription of each of the ribosomal protein genes, although the total transcription of mRNA in the cells is relatively unaffected by the temperature shock. The precisely coordinated response of these genes, which are scattered throughout the genome, suggests that either they or the enzyme which transcribes them has unique properties. In certain S. cerevisiae mutants, the synthesis of ribosomal proteins never recovers from a temperature shift. Yet both the decline and the resumption of transcription of these genes during the 30 min after the temperature shift are indistinguishable from those in wild-type cells. The failure of the mutant cells to grow at the restrictive temperature appears to be due to their inability to process the RNA transcribed from genes which have introns (Rosbash et al., Cell 24:679-686, 1981), a large proportion of which appear to be ribosomal protein genes.

scholarly journals A suppressor of temperature-sensitive rna mutations that affect mRNA metabolism in Saccharomyces cerevisiae.

1982 ◽  
Vol 2 (5) ◽  
pp. 571-577 ◽  
Author(s):  
N J Pearson ◽  
P C Thorburn ◽  
J E Haber
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Temperature Sensitive ◽  
Mrna Levels ◽  
Ribosomal Protein Genes ◽  
Mrna Synthesis ◽  
Yeast Saccharomyces Cerevisiae ◽  
Double Mutation ◽  
Mrna Metabolism ◽  
Intervening Sequences ◽  
Dominant Suppressor

We have isolated a dominant suppressor of rna mutation (SRN1) that relieves the temperature-sensitive inhibition of mRNA synthesis of ribosomal protein genes in the yeast Saccharomyces cerevisiae. The suppressor was selected for its ability to alleviate simultaneously the temperature-sensitive growth phenotypes of rna2 and rna6. Several independently isolated suppressors appeared to be recessive lethal mutations. One suppressor, SRN1, was recovered as viable in haploid strains. SRN1 can suppress rna2, rna3, rna4, rna5, rna6, and rna8 singly or in pairs, although some combinations of rna mutations are less well suppressed than others. The suppressor allows strains with rna mutations to grow at 34 degrees C but is unable to suppress at 37 degrees C; however, SRN1 does not, by itself, prevent growth at 37 degrees C. In addition, SRN1 suppresses the rna1 mutation which affects general mRNA levels and also leads to the accumulation of precursor tRNA for those tRNAs that have intervening sequences. SRN1 can suppress the rna1 mutation as well as the rna1 rna2 double mutation at 34 degrees C. The suppressor does not affect the temperature-sensitive growth of two unrelated temperature-sensitive mutations, cdc4 and cdc7.

scholarly journals Continued functioning of the secretory pathway is essential for ribosome synthesis.

1994 ◽  
Vol 14 (4) ◽  
pp. 2493-2502 ◽  
Author(s):  
K Mizuta ◽  
J R Warner
Keyword(s):  
Ribosomal Protein ◽  
Ribosomal Proteins ◽  
Secretory Pathway ◽  
Regulatory Elements ◽  
Carboxypeptidase Y ◽  
Temperature Sensitive ◽  
Mrna Levels ◽  
Nonpermissive Temperature ◽  
Ribosome Synthesis ◽  
Secretion Pathway

To explore the regulatory elements that maintain the balanced synthesis of the components of the ribosome, we isolated a temperature-sensitive (ts) mutant of Saccharomyces cerevisiae in which transcription both of rRNA and of ribosomal protein genes is defective at the nonpermissive temperature. Temperature sensitivity for growth is recessive and segregates 2:2. A gene that complements the ts phenotype was cloned from a genomic DNA library. Sequence analysis revealed that this gene is SLY1, encoding a protein essential for protein and vesicle transport between the endoplasmic reticulum and the Golgi apparatus. In the strain carrying our ts allele of SLY1, accumulation of the carboxypeptidase Y precursor was detected at the nonpermissive temperature, indicating that the secretory pathway is defective. To ask whether the effect of the ts allele on ribosome synthesis was specific for sly1 or was a general result of the inactivation of the secretion pathway, we assayed the levels of mRNA for several ribosomal proteins in cells carrying ts alleles of sec1, sec7, sec11, sec14, sec18, sec53, or sec63, representing all stages of secretion. In each case, the mRNA levels were severely depressed, suggesting that this is a common feature in mutants of protein secretion. For the mutants tested, transcription of rRNA was also substantially reduced. Furthermore, treatment of a sensitive strain with brefeldin A at a concentration sufficient to block the secretion pathway also led to a decrease of the level of ribosomal protein mRNA, with kinetics suggesting that the effect of a secretion defect is manifest within 15 to 30 min. We conclude that the continued function of the entire secretion pathway is essential for the maintenance of ribosome synthesis. The apparent coupling of membrane synthesis and ribosome synthesis suggest the existence of a regulatory network that connects the production of the various structural elements of the cell.

scholarly journals SSB, Encoding a Ribosome-Associated Chaperone, Is Coordinately Regulated with Ribosomal Protein Genes

1999 ◽  
Vol 181 (10) ◽  
pp. 3136-3143 ◽  
Author(s):  
Nelson Lopez ◽  
John Halladay ◽  
William Walter ◽  
Elizabeth A. Craig
Keyword(s):  
Heat Shock ◽  
Ribosomal Protein ◽  
Ribosomal Proteins ◽  
Chain Complex ◽  
Mrna Levels ◽  
Ribosomal Protein Genes ◽  
Genes Encoding ◽  
Synthetic Capacity ◽  
Translational Apparatus ◽  
Temperature Upshift

ABSTRACT Genes encoding ribosomal proteins and other components of the translational apparatus are coregulated to efficiently adjust the protein synthetic capacity of the cell. Ssb, a Saccharomyces cerevisiae Hsp70 cytosolic molecular chaperone, is associated with the ribosome-nascent chain complex. To determine whether this chaperone is coregulated with ribosomal proteins, we studied the mRNA regulation of SSB under several environmental conditions. Ssb and the ribosomal protein rpL5 mRNAs were up-regulated upon carbon upshift and down-regulated upon amino acid limitation, unlike the mRNA of another cytosolic Hsp70, Ssa. Ribosomal protein and Ssb mRNAs, like many mRNAs, are down-regulated upon a rapid temperature upshift. The mRNA reduction of several ribosomal protein genes and Ssb was delayed by the presence of an allele, EXA3-1, of the gene encoding the heat shock factor (HSF). However, upon a heat shock theEXA3-1 mutation did not significantly alter the reduction in the mRNA levels of two genes encoding proteins unrelated to the translational apparatus. Analysis of gene fusions indicated that the transcribed region, but not the promoter of SSB, is sufficient for this HSF-dependent regulation. Our studies suggest that Ssb is regulated like a core component of the ribosome and that HSF is required for proper regulation of SSB and ribosomal mRNA after a temperature upshift.

scholarly journals Hierarchy of elements regulating synthesis of ribosomal proteins in Saccharomyces cerevisiae.

1981 ◽  
Vol 1 (11) ◽  
pp. 1016-1023 ◽  
Author(s):  
D R Kief ◽  
J R Warner
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Protein Synthesis ◽  
Ribosomal Protein ◽  
Ribonucleic Acid ◽  
Ribosomal Proteins ◽  
Temperature Sensitive ◽  
Wild Type ◽  
Messenger Ribonucleic Acid ◽  
Ribosomal Protein Synthesis ◽  
Stimulation Of

Saccharomyces cerevisiae cells respond to a heat shock by temporarily slowing the synthesis of ribosomal proteins (C. Gorenstein and J. R. Warner, Proc. Natl. Acad. Sci. U.S.A. 73:1574-1551, 1976). When cultures growing oxidatively on ethanol as the sole carbon source were shifted from 23 to 36 degrees C, the synthesis of ribosomal proteins was coordinately inhibited twice as rapidly and 45% more severely than in comparable cultures growing fermentatively on glucose. Within 15 min, the relative rates of synthesis of at least 30 ribosomal proteins declined to less than one-sixth their initial values, whereas the overall rate of protein synthesis increased at least threefold. We suggest that this is due primarily to controls at the level of synthesis of messenger ribonucleic acid for ribosomal proteins but may also involve changes in messenger ribonucleic acid stability. In contrast, a nutritional shift-up causes a stimulation of the synthesis of ribosomal proteins. Experiments designed to determine the hierarchy of stimuli affecting the synthesis of these proteins demonstrated that temperature shock was dominant to glucose stimulation. When a culture growing on ethanol was shifted from 23 to 36 degrees C and glucose was added shortly afterward, the decline in ribosomal protein synthesis continued unabated. However, in wild-type cells ribosomal protein synthesis began to recover within 15 min. In mutants temperature sensitive for ribosome synthesis, e.g., rna2, there was no recovery in the synthesis of most ribosomal proteins, suggesting that the product of rna2 is essential for the production of these proteins under all vegetative conditions.

scholarly journals Posttranscriptional regulation and assembly into ribosomes of a Saccharomyces cerevisiae ribosomal protein-beta-galactosidase fusion.

1985 ◽  
Vol 5 (12) ◽  
pp. 3436-3442 ◽  
Author(s):  
L Gritz ◽  
N Abovich ◽  
J L Teem ◽  
M Rosbash
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Fusion Protein ◽  
Ribosomal Protein ◽  
Posttranscriptional Regulation ◽  
Fusion Gene ◽  
Mrna Levels ◽  
Galactosidase Activity ◽  
Ribosomal Protein Genes ◽  
Coding Region ◽  
Beta Galactosidase

To study the regulation of ribosomal protein genes, we constructed a 'lacZ fusion of the Saccharomyces cerevisiae RP51A gene, containing the first 64 codons of RP51A. In a strain lacking an intact RP51A gene (cells are viable due to the presence of an active RP51B gene), beta-galactosidase activity is 10-fold greater than in a strain containing RP51A. RP51A-lacZ mRNA levels are equal in the two strains, indicating that regulation is posttranscriptional. In the absence of the RP51A gene, the fusion protein is predominantly cytoplasmic and associated with polysomes, whereas in the presence of RP51A, the fusion protein is predominantly nuclear, and none is associated with polysomes. Deletions were made in the RP51A-coding portion of the fusion gene. The most extensively deleted gene, containing only the first seven RP51A codons fused to lacZ, produced a high level of beta-galactosidase activity in both the presence and the absence of the RP51A gene. In both cases, little or none of this shorter fusion protein was found associated with polysomes. Thus, a regulatory site (or sites) lies in the protein-coding region of RP51A. We suggest that posttranscriptional regulation of the rp51 fusion protein is related to assembly of the protein into ribosomes.

scholarly journals Continued functioning of the secretory pathway is essential for ribosome synthesis

1994 ◽  
Vol 14 (4) ◽  
pp. 2493-2502
Author(s):  
K Mizuta ◽  
J R Warner
Keyword(s):  
Ribosomal Protein ◽  
Ribosomal Proteins ◽  
Secretory Pathway ◽  
Regulatory Elements ◽  
Carboxypeptidase Y ◽  
Temperature Sensitive ◽  
Mrna Levels ◽  
Nonpermissive Temperature ◽  
Ribosome Synthesis ◽  
Secretion Pathway

To explore the regulatory elements that maintain the balanced synthesis of the components of the ribosome, we isolated a temperature-sensitive (ts) mutant of Saccharomyces cerevisiae in which transcription both of rRNA and of ribosomal protein genes is defective at the nonpermissive temperature. Temperature sensitivity for growth is recessive and segregates 2:2. A gene that complements the ts phenotype was cloned from a genomic DNA library. Sequence analysis revealed that this gene is SLY1, encoding a protein essential for protein and vesicle transport between the endoplasmic reticulum and the Golgi apparatus. In the strain carrying our ts allele of SLY1, accumulation of the carboxypeptidase Y precursor was detected at the nonpermissive temperature, indicating that the secretory pathway is defective. To ask whether the effect of the ts allele on ribosome synthesis was specific for sly1 or was a general result of the inactivation of the secretion pathway, we assayed the levels of mRNA for several ribosomal proteins in cells carrying ts alleles of sec1, sec7, sec11, sec14, sec18, sec53, or sec63, representing all stages of secretion. In each case, the mRNA levels were severely depressed, suggesting that this is a common feature in mutants of protein secretion. For the mutants tested, transcription of rRNA was also substantially reduced. Furthermore, treatment of a sensitive strain with brefeldin A at a concentration sufficient to block the secretion pathway also led to a decrease of the level of ribosomal protein mRNA, with kinetics suggesting that the effect of a secretion defect is manifest within 15 to 30 min. We conclude that the continued function of the entire secretion pathway is essential for the maintenance of ribosome synthesis. The apparent coupling of membrane synthesis and ribosome synthesis suggest the existence of a regulatory network that connects the production of the various structural elements of the cell.

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