Saccharomyces cerevisiae
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA305091 | ENA |
REPOSITORIES: ENA
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Project description:The cell cycle is thought to be initiated by cyclin-dependent kinases (Cdk) inactivating transcriptional inhibitors of cell cycle gene-expression. In budding yeast, the G1 cyclin Cln3-Cdk1 complex is thought to directly phosphorylate Whi5, thereby releasing the transcription factor SBF and committing cells to division. Here, we report that Cln3-Cdk1 does not phosphorylate Whi5, but instead phosphorylates the RNA Polymerase II subunit Rpb1’s C-terminal domain (CTD) on S5 of its heptapeptide repeats. Cln3-Cdk1 binds SBF-regulated promoters(8) and Cln3’s function can be performed by the canonical S5 kinase Ccl1-Kin28 when synthetically recruited to SBF. Thus, Cln3-Cdk1 triggers cell division by phosphorylating Rpb1 at SBF-regulated promoters to promote transcription. Our findings blur the distinction between cell cycle and transcriptional Cdks to highlight the ancient relationship between these processes.
2021-12-01 | GSE169271 | GEO
Project description:Yeast cell cycle transcription dynamics in two S. cerevisae strains: BF264-15DU (MATa ade1 his2 leu2-3, 112 trp1-1 ura3Dns, bar1) [referred to as wild type] and a mutant of the wild type strain, clb1,2,3,4,5,6 GAL1-CLB1, [referred to as cyclin mutant] that does not express S-phase and mitotic cyclins. Both strains were synchronized by elutriation and released into YEP 2% dextrose/1M sorbitol at 30c. 15 samples were taken at 16 min intervals covering ~2 cycles in wild-type and ~1.5 cycles for the mutants. A significant fraction of the Saccharomyces cerevisiae genome is transcribed periodically during the cell division cycle, suggesting that properly timed gene expression is important for regulating cell cycle events. Genomic analyses of transcription factor localization and expression dynamics suggest that a network of sequentially expressed transcription factors could control the temporal program of transcription during the cell cycle. However, directed studies interrogating small numbers of genes indicate that their periodic transcription is governed by the activity of cyclin-dependent kinases (CDKs). To determine the extent to which the global cell cycle transcription program is controlled by cyclin/CDK complexes, we compared genome-wide transcription dynamics in wild type budding yeast to mutants that do not express S-phase and mitotic cyclins. Experiment Overall Design: Cell cycle synchrony/time series experiments. G1 cells collected by elutriation was examined over time for 2 cell cycles. Strains compared: wild type vs cyclin mutants. 15 samples per time course at 16 min resolution. 2 biological replicates per strain.
2008-06-20 | E-GEOD-8799 | biostudies-arrayexpress
Project description:We previously proposed a detailed, 39-variable model for the network of cyclin-dependent kinases (Cdks) that controls progression along the successive phases of the mammalian cell cycle. Here, we propose a skeleton, 5-variable model for the Cdk network that can be seen as the backbone of the more detailed model for the mammalian cell cycle. In the presence of sufficient amounts of growth factor, the skeleton model also passes from a stable steady state to sustained oscillations of the various cyclin/Cdk complexes. This transition corresponds to the switch from quiescence to cell proliferation. Sequential activation of the cyclin/Cdk complexes allows the ordered progression along the G1, S, G2 and M phases of the cell cycle. The 5-variable model can also account for the existence of a restriction point in G1, and for endoreplication. Like the detailed model, it contains multiple oscillatory circuits and can display complex oscillatory behaviour such as quasi-periodic oscillations and chaos. We compare the dynamical properties of the skeleton model with those of the more detailed model for the mammalian cell cycle.
2024-09-02 | BIOMD0000000941 | BioModels
Project description:Cyclin dependent kinases (CDKs) are high value therapeutical targets owing to their important roles in regulating transcription and the cell cycle — two pathways commonly altered in cancer and especially in multiple myeloma (MM). Among CDKs, CDK7 uniquely bridges cell cycle and transcriptional control by activating other cell cycle CDKs and forming the general transcription factor TFIIH. Utilizing a recently developed highly selective covalent inhibitor of CDK7, we demonstrate that CDK7 inhibition elicits a strong therapeutic response in MM blocking proliferation in vitro and driving tumor regression and prolonged survival in vivo. CDK7 inhibition counteracts molecular hallmarks of deregulated cell cycle control at the G1/S checkpoint. Additionally, we show CDK7 inhibition selectively downregulates oncogenic E2F and cell cycle gene expression programs. Combination treatment with JQ1 which target oncogenic enhancer driven gene expression programs proved highly synergistic. These results support CDK7 as an attractive and therapeutically actionable molecular vulnerability in MM. Cell count normalized RNA-seq in Sensitive MM cell lines (H929 and MM1S; 24 total samples; 3 technical replicates) upon treatment with the selective covalent CDK7 inhibitor YKL-5-124 Mariateresa,Fulciniti Nikhil,Munshi
2022-04-01 | GSE172444 | GEO
Project description:Cyclin dependent kinases (CDKs) are high value therapeutical targets owing to their important roles in regulating transcription and the cell cycle — two pathways commonly altered in cancer and especially in multiple myeloma (MM). Among CDKs, CDK7 uniquely bridges cell cycle and transcriptional control by activating other cell cycle CDKs and forming the general transcription factor TFIIH. Utilizing a recently developed highly selective covalent inhibitor of CDK7, we demonstrate that CDK7 inhibition elicits a strong therapeutic response in MM blocking proliferation in vitro and driving tumor regression and prolonged survival in vivo. CDK7 inhibition counteracts molecular hallmarks of deregulated cell cycle control at the G1/S checkpoint. Additionally, we show CDK7 inhibition selectively downregulates oncogenic E2F and cell cycle gene expression programs. Combination treatment with JQ1 which target oncogenic enhancer driven gene expression programs proved highly synergistic. These results support CDK7 as an attractive and therapeutically actionable molecular vulnerability in MM. Cell count normalized RNA-seq in Resistant MM cell lines (XG1 and AMO1; 18 total samples; 3 technical replicates) upon treatment with the selective covalent CDK7 inhibitor YKL-5-124 Mariateresa,Fulciniti Nikhil,Munshi
2022-04-01 | GSE172443 | GEO
Project description:Cyclin dependent kinases (CDKs) are high value therapeutical targets owing to their important roles in regulating transcription and the cell cycle — two pathways commonly altered in cancer and especially in multiple myeloma (MM). Among CDKs, CDK7 uniquely bridges cell cycle and transcriptional control by activating other cell cycle CDKs and forming the general transcription factor TFIIH. Utilizing a recently developed highly selective covalent inhibitor of CDK7, we demonstrate that CDK7 inhibition elicits a strong therapeutic response in MM blocking proliferation in vitro and driving tumor regression and prolonged survival in vivo. CDK7 inhibition counteracts molecular hallmarks of deregulated cell cycle control at the G1/S checkpoint. Additionally, we show CDK7 inhibition selectively downregulates oncogenic E2F and cell cycle gene expression programs. Combination treatment with JQ1 which target oncogenic enhancer driven gene expression programs proved highly synergistic. These results support CDK7 as an attractive and therapeutically actionable molecular vulnerability in MM. Cell count normalized RNA-seq in Resistant MM cell lines (XG1 and AMO1; 18 total samples; 3 technical replicates) upon treatment with the selective covalent CDK7 inhibitor YKL-5-124 Mariateresa,Fulciniti Nikhil,Munshi
2022-04-01 | GSE172442 | GEO
Project description:In the budding yeast Saccharomyces cerevisiae, transcription factors (TFs) regulate the periodic expression of many genes during the cell cycle, including gene products required for progression through cell-cycle events. Experimental evidence coupled with quantitative models suggest that a network of interconnected TFs is capable of regulating periodic genes over the cell cycle. Importantly, these dynamical models were built on transcriptomics data and assumed that TF protein levels and activity are directly correlated with mRNA abundance. To ask whether TF transcripts match protein expression levels as cells progress through the cell cycle, we applied a multiplexed targeted mass spectrometry approach (parallel reaction monitoring) on synchronized populations of cells. We found that protein expression of many TFs and cell-cycle regulators closely followed their respective mRNA transcript dynamics in cycling wild-type cells. Discordant mRNA/protein expression dynamics were also observed for a subset of cell-cycle TFs and for proteins targeted for degradation by E3 ubiquitin ligase complexes such as SCF (Skp1/Cul1/F-box) and APC/C (anaphase-promoting complex/cyclosome). We further profiled mutant cells lacking B-type cyclin/CDK activity (clb1-6), where oscillations in ubiquitin ligase activity, cyclin/CDKs, and cell-cycle progression are halted. We found that a number of proteins were no longer periodically degraded in clb1-6 mutants compared to wild type, highlighting the importance of post-transcriptional regulation. Finally, the TF complexes responsible for activating G1/S transcription (SBF and MBF) were more constitutively expressed at the protein level than their periodic mRNA expression levels in both wild-type and mutant cells. This comprehensive investigation of cell-cycle regulators reveals that multiple layers of regulation (transcription, protein stability, and proteasome targeting) affect protein expression dynamics during the cell cycle.
| PXD010937 | panorama
Project description:The p53 tumour suppressor is a transcription factor that can regulate the expression of numerous genes encoding either proteins or microRNAs (miRNAs). The predominant outcomes of a typical p53 response are the initiation of apoptotic cascades and the activation of cell cycle checkpoints. HT29-tsp53 cells express a temperature sensitive variant of p53 and in the absence of exogenous DNA damage, these cells preferentially undergo G1 phase cell cycle arrest at the permissive temperature that correlates with increased expression of the cyclin-dependent kinase inhibitor p21WAF1. Recent evidence also suggests that a variety of miRNAs can induce G1 arrest by inhibiting the expression of proteins like CDK4 and CDK6. Here we used oligonucleotide microarrays to identify p53-regulated miRNAs that are induced in these cells undergoing G1 arrest. At the permissive temperature, the expression of several miRNAs was increased through a combination of either transcriptional or post-transcriptional regulation. In particular, miR-34a-5p, miR-143-3p and miR-145-5p were strongly induced and they reached levels comparable to that of reference miRNAs (miR-191 and miR-103). Importantly, miR-34a-5p and miR-145-5p are known to silence the Cdk4 and/or Cdk6 G1 cyclin-dependent kinases (cdks). Surprisingly, there was no p53-dependent decrease in the expression of either of these G1 cdks. To search for other potential targets of p53-regulated miRNAs, p53-downregulated mRNAs were identified through parallel microarray analysis of mRNA expression. Once again, there was no clear effect of p53 on the repression of mRNAs under these conditions despite a remarkable increase in p53-induced mRNA expression. Therefore, despite a strong p53 transcriptional response, there was no clear evidence that p53-responsive miRNA contributed to gene silencing. Taken together, the changes in cell cycle distribution in this cell line at the permissive temperature is likely attributable to transcriptional upregulation of the CDKN1A mRNA and p21WAF1 protein and not to the down regulation of CDK4 or CDK6 by p53-regulated miRNAs. Two independent experiments were performed with 2 samples in each experiment (1 control and 1 treatment condition). In the control sample, RNA was isolated cells maintained at the restrictive temperature (37ËC). The treatment treated sample, was incubated for 16 hours at the permissive temperature (32ËC).
2016-01-07 | E-GEOD-76576 | biostudies-arrayexpress
Project description:Entry into the cell cycle requires activation of G1 cyclin-dependent kinases (CDKs) and the initiation of the G1/S transcriptional program. Unregulated transcription of this gene expression program can lead to genomic instability and aneuploidy. In fission yeast, the MBF complex is the key transcription factor that drives early cell-cycle gene expression. MBF-dependent transcription is triggered in metaphase and is suppressed at the end of S phase by a robust feedback mechanism involving the cyclin Cig2 and the co-repressors Nrm1 and Yox1. Under replicative stress, Yox1 is phosphorylated to release its repressive activity; however, the precise mechanism activating MBF in an unperturbed cell cycle remains unclear. Here, we identify Nrm1 as the primary target of the cell cycle machinery in regulating MBF activity through a two-step control mechanism. We demonstrate that CDK1-mediated phosphorylation of Nrm1 initiates its release, along with Yox1, from chromatin in metaphase. This mechanism overlaps with the irreversible degradation of unphosphorylated Nrm1 (which originates from de novo synthesis or by dephosphorylation of pre-existing Nrm1 during anaphase), preventing its re-association with MBF until the end of the following S phase. These parallel mechanisms, which sense cell cycle status, create a regulated window in which MBF-dependent transcription is relieved from repression, supporting orderly cell cycle progression.
2025-07-23 | GSE287772 | GEO
Project description:Cell cycle progression is governed by complexes of the cyclin-dependent kinases (CDKs) and their regulatory subunits cyclin and Cks1. CDKs phosphorylate hundreds of substrates, often at multiple sites. Multisite phosphorylation depends on Cks1, which binds initial priming phosphorylation sites to promote secondary phosphorylation at other sites. Here, we describe a similar role for a recently discovered phosphate-binding pocket (PP) on B-type cyclins. Mutation of the PP in Clb2, the major mitotic cyclin of budding yeast, alters bud morphology and delays the onset of anaphase. Mutation of the PP reduces multi-site phosphorylation of CDK substrates in vitro, including the Cdc16 and Cdc27 subunits of the anaphase-promoting complex/cyclosome and the Bud6 and Spa2 subunits of the polarisome. We conclude that the cyclin PP, like Cks1, controls the pattern of multisite phosphorylation on CDK substrates, thereby helping to establish the robust timing of cell-cycle events.
2025-05-19 | PXD062428 | Pride