scholarly journals Cep57 and Cep57L1 maintain centriole engagement in interphase to ensure centriole duplication cycle

2021 ◽  
Vol 220 (3) ◽  
Author(s):  
Kei K. Ito ◽  
Koki Watanabe ◽  
Haruki Ishida ◽  
Kyohei Matsuhashi ◽  
Takumi Chinen ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Chromosome Segregation ◽  
Copy Number ◽  
Cell Cycle Progression ◽  
Dependent Manner ◽  
Tight Control ◽  
Cycle Progression ◽  
Centriole Duplication ◽  
Duplication Cycle

Centrioles duplicate in interphase only once per cell cycle. Newly formed centrioles remain associated with their mother centrioles. The two centrioles disengage at the end of mitosis, which licenses centriole duplication in the next cell cycle. Therefore, timely centriole disengagement is critical for the proper centriole duplication cycle. However, the mechanisms underlying centriole engagement during interphase are poorly understood. Here, we show that Cep57 and Cep57L1 cooperatively maintain centriole engagement during interphase. Codepletion of Cep57 and Cep57L1 induces precocious centriole disengagement in interphase without compromising cell cycle progression. The disengaged daughter centrioles convert into centrosomes during interphase in a Plk1-dependent manner. Furthermore, the centrioles reduplicate and the centriole number increases, which results in chromosome segregation errors. Overall, these findings demonstrate that the maintenance of centriole engagement by Cep57 and Cep57L1 during interphase is crucial for the tight control of centriole copy number and thus for proper chromosome segregation.

scholarly journals Cep57 and Cep57L1 cooperatively maintain centriole engagement during interphase to ensure proper centriole duplication cycle

2020 ◽  
Author(s):  
Kei K. Ito ◽  
Koki Watanabe ◽  
Haruki Ishida ◽  
Kyohei Matsuhashi ◽  
Takumi Chinen ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Chromosome Segregation ◽  
Copy Number ◽  
Cell Cycle Progression ◽  
Dependent Manner ◽  
Tight Control ◽  
Cycle Progression ◽  
Centriole Duplication ◽  
Duplication Cycle

Centrioles duplicate in the interphase only once per cell cycle. Newly formed centrioles remain associated with their mother centrioles. The two centrioles disengage at the end of mitosis, which licenses centriole duplication in the next cell cycle. Therefore, timely centriole disengagement is critical for the proper centriole duplication cycle. However, the mechanisms underlying centriole engagement during interphase are poorly understood. Here, we show that Cep57 and Cep57L1 cooperatively maintain centriole engagement during interphase. Co-depletion of Cep57 and Cep57L1 induces precocious centriole disengagement in the interphase without compromising cell cycle progression. The disengaged daughter centrioles convert into centrosomes during interphase in a Plk1-dependent manner. Furthermore, the centrioles reduplicate and the centriole number increases, which results in chromosome segregation errors. Overall, these findings demonstrate that the maintenance of centriole engagement by Cep57 and Cep57L1 during interphase is crucial for the tight control of centriole copy number and thus for proper chromosome segregation.

scholarly journals Non‐redundant functions of H2A.Z.1 and H2A.Z.2 in chromosome segregation and cell cycle progression

EMBO Reports ◽  
2021 ◽  
Author(s):  
Raquel Sales‐Gil ◽  
Dorothee C Kommer ◽  
Ines J Castro ◽  
Hasnat A Amin ◽  
Veronica Vinciotti ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Chromosome Segregation ◽  
Cell Cycle Progression ◽  
Cycle Progression ◽  
Redundant Functions

scholarly journals Carvedilol Inhibits Angiotensin II-Induced Proliferation and Contraction in Hepatic Stellate Cells through the RhoA/Rho-Kinase Pathway

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Ying Wu ◽  
Zhen Li ◽  
Sining Wang ◽  
Aiyuan Xiu ◽  
Chunqing Zhang
Keyword(s):  
Cell Cycle ◽  
Angiotensin Ii ◽  
Liver Fibrosis ◽  
Cell Cycle Progression ◽  
Rho Kinase ◽  
Cell Counting ◽  
Type I ◽  
Dependent Manner ◽  
Ang Ii ◽  
Cycle Progression

Aim. Carvedilol is a nonselective beta-blocker used to reduce portal hypertension. This study investigated the effects and potential mechanisms of carvedilol in angiotensin II- (Ang II-) induced hepatic stellate cell (HSC) proliferation and contraction. Methods. The effect of carvedilol on HSC proliferation was measured by Cell Counting Kit-8 (CCK-8). Cell cycle progression and apoptosis in HSCs were determined by flow cytometry. A collagen gel assay was used to confirm HSC contraction. The extent of liver fibrosis in mice was evaluated by hematoxylin-eosin (H&E) and Sirius Red staining. Western blot analyses were performed to detect the expression of collagen I, collagen III, α-smooth muscle actin (α-SMA), Ang II type I receptor (AT1R), RhoA, Rho-kinase 2 (ROCK2), and others. Results. The results showed that carvedilol inhibited HSC proliferation and arrested the cell cycle at the G0/G1 phase in a dose-dependent manner. Carvedilol also modulated Bcl-2 family proteins and increased apoptosis in Ang II-treated HSCs. Furthermore, carvedilol inhibited HSC contraction induced by Ang II, an effect that was associated with AT1R-mediated RhoA/ROCK2 pathway interference. In addition, carvedilol reduced α-SMA expression and collagen deposition and attenuated liver fibrosis in carbon tetrachloride (CCl4)-treated mice. The in vivo data further confirmed that carvedilol inhibited the expression of angiotensin-converting enzyme (ACE), AT1R, RhoA, and ROCK2. Conclusions. The results indicated that carvedilol dose-dependently inhibited Ang II-induced HSC proliferation by impeding cell cycle progression, thus alleviating hepatic fibrosis. Furthermore, carvedilol could inhibit Ang II-induced HSC contraction by interfering with the AT1R-mediated RhoA/ROCK2 pathway.

scholarly journals Lamina-associated polypeptide 2α regulates cell cycle progression and differentiation via the retinoblastoma–E2F pathway

2006 ◽  
Vol 173 (1) ◽  
pp. 83-93 ◽  
Author(s):  
Daniela Dorner ◽  
Sylvia Vlcek ◽  
Nicole Foeger ◽  
Andreas Gajewski ◽  
Christian Makolm ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Progression ◽  
Target Genes ◽  
Serum Starvation ◽  
Dependent Manner ◽  
Cycle Progression ◽  
Promoter Sequences ◽  
Delayed Entry ◽  
Accelerated Proliferation

Lamina-associated polypeptide (LAP) 2α is a nonmembrane-bound LAP2 isoform that forms complexes with nucleoplasmic A-type lamins. In this study, we show that the overexpression of LAP2α in fibroblasts reduced proliferation and delayed entry into the cell cycle from a G0 arrest. In contrast, stable down-regulation of LAP2α by RNA interference accelerated proliferation and interfered with cell cycle exit upon serum starvation. The LAP2α-linked cell cycle phenotype is mediated by the retinoblastoma (Rb) protein because the LAP2α COOH terminus directly bound Rb, and overexpressed LAP2α inhibited E2F/Rb-dependent reporter gene activity in G1 phase in an Rb-dependent manner. Furthermore, LAP2α associated with promoter sequences in endogenous E2F/Rb-dependent target genes in vivo and negatively affected their expression. In addition, the expression of LAP2α in proliferating preadipocytes caused the accumulation of hypophosphorylated Rb, which is reminiscent of noncycling cells, and initiated partial differentiation into adipocytes. The effects of LAP2α on cell cycle progression and differentiation may be highly relevant for the cell- and tissue-specific phenotypes observed in laminopathic diseases.

Epigenetic dynamics across the cell cycle

2010 ◽  
Vol 48 ◽  
pp. 107-120 ◽  
Author(s):  
Tony Bou Kheir ◽  
Anders H. Lund
Keyword(s):  
Cell Cycle ◽  
Chromosome Segregation ◽  
Cell Cycle Progression ◽  
Current Knowledge ◽  
Chromatin Condensation ◽  
Chromatin Modifications ◽  
Cycle Progression ◽  
Daughter Cells ◽  
Mammalian Cell Cycle ◽  
Regulate Cell Cycle Progression

Progression of the mammalian cell cycle depends on correct timing and co-ordination of a series of events, which are managed by the cellular transcriptional machinery and epigenetic mechanisms governing genome accessibility. Epigenetic chromatin modifications are dynamic across the cell cycle, and are shown to influence and be influenced by cell-cycle progression. Chromatin modifiers regulate cell-cycle progression locally by controlling the expression of individual genes and globally by controlling chromatin condensation and chromosome segregation. The cell cycle, on the other hand, ensures a correct inheritance of epigenetic chromatin modifications to daughter cells. In this chapter, we summarize the current knowledge on the dynamics of epigenetic chromatin modifications during progression of the cell cycle.

scholarly journals Cell Cycle Progression in Monkey Cells Expressing Simian Virus 40 Small t Antigen from Adenovirus Vectors

1998 ◽  
Vol 72 (12) ◽  
pp. 9637-9644 ◽  
Author(s):  
Alan K. Howe ◽  
Stéphanie Gaillard ◽  
John S. Bennett ◽  
Kathleen Rundell
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Progression ◽  
Mapk Pathway ◽  
Simian Virus 40 ◽  
Simian Virus ◽  
T Antigen ◽  
Dependent Manner ◽  
Cycle Progression ◽  
Adenovirus Vectors ◽  
Small T Antigen

ABSTRACT The simian virus 40 small t antigen (small-t) is required for optimal viral replication and transformation, especially during the infection of nondividing cells, suggesting that the function of small-t is to promote cell cycle progression. The mechanism through which small-t promotes cell growth reflects, in part, its binding and inhibition of protein phosphatase 2A (PP2A). The use of recombinant adenoviruses allows small-t expression in a majority of cells in a population, thus providing a convenient source of cells for biochemical analyses. In monkey kidney CV1 cells, small-t expressed from these adenovirus vectors activated the mitogen-activated protein kinase (MAPK) pathway, induced JNK activity, and increased AP-1 DNA-binding activity, all in a PP2A-dependent manner. Expression of small-t also caused an increase in the phosphorylation of the Na+/H+ antiporter, a mitogen-activated ion exchanger whose activity correlates with its phosphorylation. At least part of the antiporter phosphorylation induced by small-t reflected activation of the MAPK pathway, as suggested by results of assays using a chemical inhibitor of the MAPK-activating kinase, MEK. Finally, small-t expression from adenovirus vectors promoted efficient cell cycle progression by growth-arrested cells. These vectors should facilitate further analysis of effects of small-t on cell cycle mediators.

scholarly journals Cyclin F-Chk1 synthetic lethality mediated by E2F1 degradation

2019 ◽  
Author(s):  
Kamila Burdova ◽  
Hongbin Yang ◽  
Roberta Faedda ◽  
Samuel Hume ◽  
Daniel Ebner ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Dna Replication ◽  
Cell Cycle Progression ◽  
Kinase Inhibitors ◽  
Synthetic Lethality ◽  
Checkpoint Inhibitors ◽  
Dependent Manner ◽  
Cycle Progression ◽  
Multiple Substrates ◽  
Cyclin F

SummaryCyclins are central engines of cell cycle progression when partnered with Cyclin Dependent Kinases (CDKs). Among the different cyclins controlling cell cycle progression, cyclin F does not partner with a CDK, but forms an E3 ubiquitin ligase, assembling through the F-box domain, an Skp1-Cul1-F-box (SCF) module. Although multiple substrates of cyclin F have been identified the vulnerabilities of cells lacking cyclin F are not known. Thus, we assessed viability of cells lacking cyclin F upon challenging cells with more than 200 kinase inhibitors. The screen revealed a striking synthetic lethality between Chk1 inhibition and cyclin F loss. Chk1 inhibition in cells lacking cyclin F leads to DNA replication catastrophe. The DNA replication catastrophe depends on the accumulation of E2F1 in cyclin F depleted cells. We observe that SCFcyclin F promotes E2F1 degradation after Chk1 inhibitors in a CDK dependent manner. Thus, Cyclin F restricts E2F1 activity during cell cycle and upon checkpoint inhibition to prevent DNA replication stress. Our findings pave the way for patient selection in the clinical use of checkpoint inhibitors.

scholarly journals Transcriptome profiling of embryonic retinal pigment epithelium reprogramming

2021 ◽  
Author(s):  
Jared A Tangeman ◽  
Agustín Luz-Madrigal ◽  
Sutharzan Sreeskandarajan ◽  
Erika Grajales- Esquivel ◽  
Lin Liu ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Retinal Pigment Epithelium ◽  
Cell Cycle Progression ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Enrichment Analysis ◽  
Gene Set Enrichment Analysis ◽  
Dependent Manner ◽  
Cycle Progression ◽  
Retina Development

AbstractThe plasticity of human retinal pigment epithelium (RPE) has been observed during proliferative vitreoretinopathy, a defective repair process during which injured RPE gives rise to fibrosis. In contrast, following injury, the RPE of the embryonic chicken can be reprogrammed to regenerate neural retina in an FGF2-dependent manner. To characterize the mechanisms underlying embryonic RPE reprogramming, we used laser capture microdissection to isolate RNA from 1) intact RPE, 2) transiently reprogrammed RPE (t-rRPE) 6 hours post-retinectomy, and 3) reprogrammed RPE (rRPE) 6 hours post-retinectomy with FGF2 treatment. Using RNA-seq, we observed the acute repression of genes related to cell cycle progression in the injured t-rRPE, as well as up-regulation of genes associated with injury. In contrast, the rRPE was strongly enriched for MAPK-responsive genes and retina development factors, confirming that FGF2 and the downstream MAPK cascade are the main drivers of embryonic RPE reprogramming. Clustering and pathway enrichment analysis were used to create an integrated network of the core processes associated with RPE reprogramming, including key terms pertaining to injury response, migration, actin dynamics, and cell cycle progression. Finally, we employed gene set enrichment analysis to suggest a previously uncovered role for epithelial-mesenchymal transition (EMT) machinery in the initiation of embryonic chick RPE reprogramming. The EMT program is accompanied by extensive, coordinated regulation of extracellular matrix (ECM) regulators, and these observations together suggest an early role for ECM and EMT-like dynamics during reprogramming. Our study provides for the first time an in-depth transcriptomic analysis of embryonic RPE reprogramming and will prove useful in guiding future efforts to understand proliferative disorders of the RPE and to promote retinal regeneration.

scholarly journals Functional oscillation of a multienzyme glucosome assembly during cell cycle progression

2022 ◽  
Author(s):  
Miji Jeon ◽  
Danielle L Schmitt ◽  
Minjoung Kyoung ◽  
Songon An
Keyword(s):  
Cell Cycle ◽  
Glucose Metabolism ◽  
Single Cell ◽  
Cell Biology ◽  
Cell Cycle Progression ◽  
Metabolic Adaptation ◽  
Dependent Manner ◽  
Cycle Progression ◽  
Size Dependent ◽  
A Cell

Glucose metabolism has been studied extensively to understand functional interplays between metabolism and a cell cycle. However, our understanding of cell cycle-dependent metabolic adaptation particularly in human cells remains largely elusive. Meanwhile, human enzymes in glucose metabolism are shown to functionally organize into three different sizes of a multienzyme metabolic assembly, the glucosome, to regulate glucose flux in a size-dependent manner. Here, using fluorescence single-cell imaging techniques, we discover that glucosomes spatiotemporally oscillate during a cell cycle in an assembly size-dependent manner. Importantly, their oscillation at single-cell levels is in accordance with functional contributions of glucose metabolism to cell cycle progression at a population level. Collectively, we demonstrate functional oscillation of glucosomes during cell cycle progression and thus their biological significance to human cell biology.

scholarly journals Imperatorin as a Promising Chemotherapeutic Agent against Human Larynx Cancer and Rhabdomyosarcoma Cells

Molecules ◽  
2020 ◽  
Vol 25 (9) ◽  
pp. 2046 ◽  
Author(s):  
Aneta Grabarska ◽  
Krystyna Skalicka-Woźniak ◽  
Michał Kiełbus ◽  
Magdalena Dmoszyńska-Graniczka ◽  
Paulina Miziak ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Cycle ◽  
Cell Lines ◽  
Cancer Cell ◽  
Cell Cycle Progression ◽  
Cancer Cell Lines ◽  
Larynx Cancer ◽  
Dependent Manner ◽  
Cycle Progression ◽  
Angelica Archangelica

Naturally occurring coumarins are bioactive compounds widely used in Asian traditional medicine. They have been shown to inhibit proliferation, induce apoptosis, and/or enhance the cytotoxicity of currently used drugs against a variety of cancer cell types. The aim of our study was to examine the antiproliferative activity of different linear furanocoumarins on human rhabdomyosarcoma, lung, and larynx cancer cell lines, and dissolve their cellular mechanism of action. The coumarins were isolated from fruits of Angelica archangelica L. or Pastinaca sativa L., and separated using high-performance counter-current chromatography (HPCCC). The identity and purity of isolated compounds were confirmed by HPLC-DAD and NMR analyses. Cell viability and toxicity assessments were performed by means of methylthiazolyldiphenyl-tetrazolium bromide (MTT) and lactate dehydrogenase (LDH) assays, respectively. Induction of apoptosis and cell cycle progression were measured using flow cytometry analysis. qPCR method was applied to detect changes in gene expression. Linear furanocoumarins in a dose-dependent manner inhibited proliferation of cancer cells with diverse activity regarding compounds and cancer cell type specificity. Imperatorin (IMP) exhibited the most potent growth inhibitory effects against human rhabdomyosarcoma and larynx cancer cell lines owing to inhibition of the cell cycle progression connected with specific changes in gene expression, including CDKN1A. As there are no specific chemotherapy treatments dedicated to laryngeal squamous cell carcinoma and rhabdomyosarcoma, and IMP seems to be non-toxic for normal cells, our results could open a new direction in the search for effective anti-cancer agents.

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