Trans-acting regulatory mutations that alter transcription of Saccharomyces cerevisiae histone genes

1987 ◽  
Vol 7 (12) ◽  
pp. 4204-4210
Author(s):  
M A Osley ◽  
D Lycan
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Cycle ◽  
Fusion Gene ◽  
Chromosome Replication ◽  
Lacz Fusion ◽  
Histone Genes ◽  
Promoter Elements ◽  
Regulatory Mutations ◽  
Cycle Dependent ◽  
Beta Galactosidase

Using a Saccharomyces cerevisiae strain containing an integrated copy of an H2A-lacZ fusion gene, we screened for mutants which overexpressed beta-galactosidase as a way to identify genes which regulate transcription of the histone genes. Five recessive mutants with this phenotype were shown to contain altered regulatory genes because they had lost repression of HTA1 transcription which occurs upon inhibition of chromosome replication (D. E. Lycan, M. A. Osley, and L. Hereford, Mol. Cell. Biol. 7:614-621, 1987). Periodic transcription was affected in the mutants as well, since the HTA1 gene was transcribed during the G1 and G2 phases of the cell cycle, periods in the cell cycle when this gene is normally not expressed. A similar loss of cell cycle-dependent transcription was noted for two of the three remaining histone loci, while the HO and CDC9 genes continued to be expressed periodically. Using isolated promoter elements inserted into a heterologous cycl-lacZ fusion gene, we demonstrated that the mutations fell in genes which acted through a negative site in the TRT1 H2A-H2B promoter.

scholarly journals Trans-acting regulatory mutations that alter transcription of Saccharomyces cerevisiae histone genes.

1987 ◽  
Vol 7 (12) ◽  
pp. 4204-4210 ◽  
Author(s):  
M A Osley ◽  
D Lycan
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Cycle ◽  
Fusion Gene ◽  
Chromosome Replication ◽  
Lacz Fusion ◽  
Histone Genes ◽  
Promoter Elements ◽  
Regulatory Mutations ◽  
Cycle Dependent ◽  
Beta Galactosidase

Using a Saccharomyces cerevisiae strain containing an integrated copy of an H2A-lacZ fusion gene, we screened for mutants which overexpressed beta-galactosidase as a way to identify genes which regulate transcription of the histone genes. Five recessive mutants with this phenotype were shown to contain altered regulatory genes because they had lost repression of HTA1 transcription which occurs upon inhibition of chromosome replication (D. E. Lycan, M. A. Osley, and L. Hereford, Mol. Cell. Biol. 7:614-621, 1987). Periodic transcription was affected in the mutants as well, since the HTA1 gene was transcribed during the G1 and G2 phases of the cell cycle, periods in the cell cycle when this gene is normally not expressed. A similar loss of cell cycle-dependent transcription was noted for two of the three remaining histone loci, while the HO and CDC9 genes continued to be expressed periodically. Using isolated promoter elements inserted into a heterologous cycl-lacZ fusion gene, we demonstrated that the mutations fell in genes which acted through a negative site in the TRT1 H2A-H2B promoter.

Role of transcriptional and posttranscriptional regulation in expression of histone genes in Saccharomyces cerevisiae

1987 ◽  
Vol 7 (2) ◽  
pp. 614-621
Author(s):  
D E Lycan ◽  
M A Osley ◽  
L M Hereford
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Cycle ◽  
Dna Replication ◽  
Posttranscriptional Regulation ◽  
Cell Cycle Control ◽  
Dimensional Structure ◽  
Histone Genes ◽  
Transcriptional Regulatory Mechanisms ◽  
Rna Levels

We analyzed the role of posttranscriptional mechanisms in the regulation of histone gene expression in Saccharomyces cerevisiae. The rapid drop in histone RNA levels associated with the inhibition of ongoing DNA replication was postulated to be due to posttranscriptional degradation of histone transcripts. However, in analyzing the sequences required for this response, we showed that the coupling of histone RNA levels to DNA replication was due mostly, if not entirely, to transcriptional regulatory mechanisms. Furthermore, deletions which removed the negative, cell cycle control sequences from the histone promoter also uncoupled histone transcription from DNA replication. We propose that the arrest of DNA synthesis prematurely activates the regulatory pathway used in the normal cell cycle to repress transcription. Although posttranscriptional regulation did not appear to play a significant role in coupling histone RNA levels to DNA replication, it did affect the levels of histone RNA in the cell cycle. Posttranscriptional regulation could apparently restore much of the periodicity of histone RNA accumulation in cells which constitutively transcribed the histone genes. Unlike transcriptional regulation, periodic posttranscriptional regulation appears to operate on a clock which is independent of events in the mitotic DNA cycle. Posttranscriptional recognition of histone RNA must require either sequences in the 3' end of the RNA or an intact three-dimensional structure since H2A- and H2B-lacZ fusion transcripts, containing only 5' histone sequences, were insensitive to posttranscriptional controls.

scholarly journals Cell cycle–dependent phosphorylation of Sec4p controls membrane deposition during cytokinesis

2016 ◽  
Vol 214 (6) ◽  
pp. 691-703 ◽  
Author(s):  
Dante Lepore ◽  
Olya Spassibojko ◽  
Gabrielle Pinto ◽  
Ruth N. Collins
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Cycle ◽  
Membrane Trafficking ◽  
Intracellular Trafficking ◽  
Rab Gtpase ◽  
Rab Gtpases ◽  
Positive Regulator ◽  
Physiological Relevance ◽  
A Cell ◽  
Cycle Dependent

Intracellular trafficking is an essential and conserved eukaryotic process. Rab GTPases are a family of proteins that regulate and provide specificity for discrete membrane trafficking steps by harnessing a nucleotide-bound cycle. Global proteomic screens have revealed many Rab GTPases as phosphoproteins, but the effects of this modification are not well understood. Using the Saccharomyces cerevisiae Rab GTPase Sec4p as a model, we have found that phosphorylation negatively regulates Sec4p function by disrupting the interaction with the exocyst complex via Sec15p. We demonstrate that phosphorylation of Sec4p is a cell cycle–dependent process associated with cytokinesis. Through a genomic kinase screen, we have also identified the polo-like kinase Cdc5p as a positive regulator of Sec4p phosphorylation. Sec4p spatially and temporally localizes with Cdc5p exclusively when Sec4p phosphorylation levels peak during the cell cycle, indicating Sec4p is a direct Cdc5p substrate. Our data suggest the physiological relevance of Sec4p phosphorylation is to facilitate the coordination of membrane-trafficking events during cytokinesis.

scholarly journals Coupling Phosphate Homeostasis to Cell Cycle-Specific Transcription: Mitotic Activation of Saccharomyces cerevisiae PHO5 by Mcm1 and Forkhead Proteins

2009 ◽  
Vol 29 (18) ◽  
pp. 4891-4905 ◽  
Author(s):  
Santhi Pondugula ◽  
Daniel W. Neef ◽  
Warren P. Voth ◽  
Russell P. Darst ◽  
Archana Dhasarathy ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Cycle ◽  
Cell Cycle Progression ◽  
Mitotic Cell ◽  
Dependent Manner ◽  
Phosphate Homeostasis ◽  
Periodic Cell ◽  
M Phase ◽  
Cycle Dependent ◽  
Nutrient Homeostasis

ABSTRACT Cells devote considerable resources to nutrient homeostasis, involving nutrient surveillance, acquisition, and storage at physiologically relevant concentrations. Many Saccharomyces cerevisiae transcripts coding for proteins with nutrient uptake functions exhibit peak periodic accumulation during M phase, indicating that an important aspect of nutrient homeostasis involves transcriptional regulation. Inorganic phosphate is a central macronutrient that we have previously shown oscillates inversely with mitotic activation of PHO5. The mechanism of this periodic cell cycle expression remains unknown. To date, only two sequence-specific activators, Pho4 and Pho2, were known to induce PHO5 transcription. We provide here evidence that Mcm1, a MADS-box protein, is essential for PHO5 mitotic activation. In addition, we found that cells simultaneously lacking the forkhead proteins, Fkh1 and Fkh2, exhibited a 2.5-fold decrease in PHO5 expression. The Mcm1-Fkh2 complex, first shown to transactivate genes within the CLB2 cluster that drive G2/M progression, also associated directly at the PHO5 promoter in a cell cycle-dependent manner in chromatin immunoprecipitation assays. Sds3, a component specific to the Rpd3L histone deacetylase complex, was also recruited to PHO5 in G1. These findings provide (i) further mechanistic insight into PHO5 mitotic activation, (ii) demonstrate that Mcm1-Fkh2 can function combinatorially with other activators to yield late M/G1 induction, and (iii) couple the mitotic cell cycle progression machinery to cellular phosphate homeostasis.

scholarly journals Cell cycle-dependent expression of thymidylate synthase in Saccharomyces cerevisiae.

1984 ◽  
Vol 4 (12) ◽  
pp. 2858-2864 ◽  
Author(s):  
R K Storms ◽  
R W Ord ◽  
M T Greenwood ◽  
B Mirdamadi ◽  
F K Chu ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Cycle ◽  
Dna Synthesis ◽  
Thymidylate Synthase ◽  
S Phase ◽  
Mrna Levels ◽  
Activity Profile ◽  
S Period ◽  
Cycle Dependent ◽  
Specific Mrna

Synchronous populations of Saccharomyces cerevisiae cells, generated by two independent methods, have been used to show that thymidylate synthase, in contrast to the vast majority of cellular proteins thus far examined, fluctuates periodically during the S. cerevisiae cell cycle. The enzyme, as assayed by two different methods, accumulated during S period and peaked in mid to late S phase, and then its level dropped. These observations suggest that both periodic synthesis and the instability of the enzyme contribute to the activity profile seen during the cell cycle. Accumulation of thymidylate synthase is determined at the level of its transcript, with synthase-specific mRNA levels increasing at least 10-fold to peak near the beginning of S period and then falling dramatically to basal levels after the onset of DNA synthesis. This mRNA peak coincided with the time during the cell cycle when thymidylate synthase levels were increasing maximally and immediately preceded the peak of DNA synthesis, for which the enzyme provides precursor dTMP.

scholarly journals Characterization of a short, cis-acting DNA sequence which conveys cell cycle stage-dependent transcription in Saccharomyces cerevisiae.

1991 ◽  
Vol 11 (1) ◽  
pp. 329-337 ◽  
Author(s):  
E M McIntosh ◽  
T Atkinson ◽  
R K Storms ◽  
M Smith
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Cycle ◽  
Dna Replication ◽  
Transcription Initiation ◽  
Site Directed Mutagenesis ◽  
Upstream Region ◽  
Sequence Element ◽  
Cell Cycle Stage ◽  
Transcription System ◽  
Cycle Dependent

Comparison of the 5'-flanking regions of several cell cycle-regulated DNA replication genes of Saccharomyces cerevisiae has revealed the presence of a common sequence, 5'-ACGCGT-3', which is upstream and proximal to mapped transcription initiation sites. This sequence, which is the cleavage site for the restriction endonuclease MluI, is present twice in the upstream region of the yeast thymidylate synthase gene TMP1. Previous studies have implicated these MluI sites as critical components in the cell cycle-dependent transcription of TMP1. In this study, we examined more closely the importance of the ACGCGT sequences for the transcription of this gene. Using site-directed mutagenesis in combination with deletion analysis and subcloning experiments, we found that (i) while both of the TMP1 MluI sites contribute to the total transcription of this gene, the distal site is predominant and (ii) the 9-bp sequence ACGCGTTAA encompassing the distal MluI site exhibits properties of a cell cycle-stage dependent upstream activation sequence element. The results of this study support the notion that the ACGCGT sequence is an integral component of a transcription system which coordinates the cell cycle-dependent expression of DNA replication genes in S. cerevisiae.

scholarly journals Signals sufficient for 3'-end formation of yeast mRNA.

1996 ◽  
Vol 16 (6) ◽  
pp. 2772-2776 ◽  
Author(s):  
Z Guo ◽  
F Sherman
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Fusion Gene ◽  
Lacz Fusion ◽  
Yeast Saccharomyces Cerevisiae ◽  
Synthetic Signal ◽  
A Site

The following three elements were previously shown to be required for 3'-end formation of mRNA in the yeast Saccharomyces cerevisiae: (i) the efficiency element TATATA or related sequences, which function by enhancing the efficiency of downstream positioning elements; (ii) the positioning element AATAAA or related sequences, which position the poly(A) site; and (iii) the actual poly(A) site, which is usually Py(A)n. In this study, we synthesized a 39-pb poly(A) signal that contained the optimum sequences of these three elements. By inserting the synthetic 3'-end-forming signal into various positions of a CYC1-lacZ fusion gene, we showed that truncated transcripts of the expected sizes were generated. Furthermore, the poly(A) sites of the truncated transcripts were mapped to the expected poly(A) site within the synthetic signal. Our findings establish that the three elements are not only necessary but also sufficient for mRNA 3'-end formation in S. cerevisiae.

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