scholarly journals Tissue-specific regulation of cyclin E transcription during Drosophila melanogaster embryogenesis

Development ◽  
2000 ◽  
Vol 127 (21) ◽  
pp. 4619-4630 ◽  
Author(s):  
L. Jones ◽  
H. Richardson ◽  
R. Saint
Keyword(s):  
Cell Cycle ◽  
Nervous System ◽  
Transcriptional Regulation ◽  
Cyclin E ◽  
Regulatory Gene ◽  
Regulatory Elements ◽  
S Phase ◽  
Epidermal Cells ◽  
Phase Cell ◽  
Tissue Specific

Cyclin E is an essential regulator of S phase entry. We have previously shown that transcriptional regulation of the gene that encodes Drosophila cyclin E, DmcycE, plays an important role in the control of the G(1) to S phase transition during development. We report here the first comprehensive analysis of the transcriptional regulation of a G(1)phase cell cycle regulatory gene during embryogenesis. Analysis of deficiencies, a genomic transformant and reporter gene constructs revealed that DmcycE transcription is controlled by a large and complex cis-regulatory region containing tissue- and stage-specific components. Separate regulatory elements for transcription in epidermal cells during cell cycles 14–16, central nervous system cells and peripheral nervous system cells were found. An additional cis-regulatory element drives transcription in thoracic epidermal cells that undergo a 17th cell cycle when other epidermal cells have arrested in G(1)phase prior to terminal differentiation. The complexity of DmcycE transcriptional regulation argues against a model in which DmcycE transcription is regulated simply and solely by G(1) to S phase transcription regulators such as RB, E2F and DP. Rather, our study demonstrates that tissue-specific transcriptional regulatory mechanisms are important components of the control of cyclin E transcription and thus of cell proliferation in metazoans.

scholarly journals Identification of HiNF-P, a Key Activator of Cell Cycle-Controlled Histone H4 Genes at the Onset of S Phase

2003 ◽  
Vol 23 (22) ◽  
pp. 8110-8123 ◽  
Author(s):  
Partha Mitra ◽  
Rong-Lin Xie ◽  
Ricardo Medina ◽  
Hayk Hovhannisyan ◽  
S. Kaleem Zaidi ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Progression ◽  
Cyclin E ◽  
S Phase ◽  
Phase Cell ◽  
Regulatory Sequences ◽  
Histone H4 ◽  
Restriction Point ◽  
Histone H4 Gene

ABSTRACT At the G1/S phase cell cycle transition, multiple histone genes are expressed to ensure that newly synthesized DNA is immediately packaged as chromatin. Here we have purified and functionally characterized the critical transcription factor HiNF-P, which is required for E2F-independent activation of the histone H4 multigene family. Using chromatin immunoprecipitation analysis and ligation-mediated PCR-assisted genomic sequencing, we show that HiNF-P interacts with conserved H4 cell cycle regulatory sequences in vivo. Antisense inhibition of HiNF-P reduces endogenous histone H4 gene expression. Furthermore, we find that HiNF-P utilizes NPAT/p220, a substrate of the cyclin E/cyclin-dependent kinase 2 (CDK2) kinase complex, as a key coactivator to enhance histone H4 gene transcription. The biological role of HiNF-P is reflected by impeded cell cycle progression into S phase upon antisense-mediated reduction of HiNF-P levels. Our results establish that HiNF-P is the ultimate link in a linear signaling pathway that is initiated with the growth factor-dependent induction of cyclin E/CDK2 kinase activity at the restriction point and culminates in the activation of histone H4 genes through HiNF-P at the G1/S phase transition.

scholarly journals HiNF-P Directly Links the Cyclin E/CDK2/p220NPAT Pathway to Histone H4 Gene Regulation at the G1/S Phase Cell Cycle Transition

2005 ◽  
Vol 25 (14) ◽  
pp. 6140-6153 ◽  
Author(s):  
Angela Miele ◽  
Corey D. Braastad ◽  
William F. Holmes ◽  
Partha Mitra ◽  
Ricardo Medina ◽  
...  
Keyword(s):  
Gene Expression ◽  
Phase Transition ◽  
Cell Cycle ◽  
Cyclin E ◽  
S Phase ◽  
Phase Cell ◽  
Genome Replication ◽  
Dependent Manner ◽  
Histone H4 ◽  
Histone H4 Gene

ABSTRACT Genome replication in eukaryotic cells necessitates the stringent coupling of histone biosynthesis with the onset of DNA replication at the G1/S phase transition. A fundamental question is the mechanism that links the restriction (R) point late in G1 with histone gene expression at the onset of S phase. Here we demonstrate that HiNF-P, a transcriptional regulator of replication-dependent histone H4 genes, interacts directly with p220NPAT, a substrate of cyclin E/CDK2, to coactivate histone genes during S phase. HiNF-P and p220 are targeted to, and colocalize at, subnuclear foci (Cajal bodies) in a cell cycle-dependent manner. Genetic or biochemical disruption of the HiNF-P/p220 interaction compromises histone H4 gene activation at the G1/S phase transition and impedes cell cycle progression. Our results show that HiNF-P and p220 form a critical regulatory module that directly links histone H4 gene expression at the G1/S phase transition to the cyclin E/CDK2 signaling pathway at the R point.

A Drosophila G1-specific cyclin E homolog exhibits different modes of expression during embryogenesis

Development ◽  
1993 ◽  
Vol 119 (3) ◽  
pp. 673-690 ◽  
Author(s):  
H.E. Richardson ◽  
L.V. O'Keefe ◽  
S.I. Reed ◽  
R. Saint
Keyword(s):  
Phase Transition ◽  
Cell Cycle ◽  
Nervous System ◽  
Peripheral Nervous System ◽  
Cyclin E ◽  
S Phase ◽  
G1 Phase ◽  
Cycle Phase ◽  
E Gene ◽  
G1 Cyclin

We have isolated a Drosophila homolog of the human G1-specific cyclin E gene. Cyclin E proteins thus constitute an evolutionarily conserved subfamily of metazoan cyclins. The Drosophila cyclin E gene, DmcycE, encodes two proteins with a common C-terminal region and unique N-terminal regions. Unlike other Drosophila cyclins, DmcycE exhibits a dynamic pattern of expression during development. DmcycE is supplied maternally, but at the completion of the cleavage divisions and prior to mitosis 14, the maternal transcripts are rapidly degraded in all cells except the pole (germ) cells. Two modes of DmcycE expression are observed in the subsequent divisions. During cycles 14, 15 and 16 in non-neural cells, DmcycE mRNA levels show no cell-cycle-associated variation. DmcycE expression in these cells is therefore independent of the cell cycle phase. In contrast, expression in proliferating embryonic peripheral nervous system cells occurs during interphase as a brief pulse that initiates before and overlaps with S phase, demonstrating the presence of a G1 phase in these embryonic neural cell cycles. DmcycE appears not to be expressed in cells that undergo endoreplication cycles during polytenization. The structural homology to human cyclin E, the ability of DmcycE to rescue a G1 cyclin-deficient yeast strain, the presence of multiple PEST sequences characteristic of G1-specific cyclins and expression during G1 phase in proliferating peripheral nervous system cells all argue that Drosophila cyclin E is a G1 cyclin. Constitutive DmcycE expression in embryonic cycles lacking a G1 phase, in contrast to expression during the G1-S phase transition in cycles exhibiting a G1 phase, implicates DmcycE expression in the regulation of the G1 to S phase transition during Drosophila embryogenesis.

scholarly journals Characterization of the S-phase-specific transcription regulatory elements in a DNA replication-independent testis-specific H2B (TH2B) histone gene.

1990 ◽  
Vol 10 (2) ◽  
pp. 585-592 ◽  
Author(s):  
I W Hwang ◽  
K Lim ◽  
C B Chae
Keyword(s):  
Cell Cycle ◽  
Dna Replication ◽  
Biological Significance ◽  
Regulatory Elements ◽  
S Phase ◽  
Phase Cell ◽  
Dependent Manner ◽  
Base Pairs ◽  
Pachytene Spermatocytes ◽  
Cloned Gene

The testis-specific H2B histone (TH2B) gene is expressed in pachytene spermatocytes of meiotic prophase I during rat spermatogenesis. The TH2B RNA and histones are not synthesized in any other tissues, and the synthesis is independent of DNA replication. However, the cloned TH2B gene has two DNA sequence elements which stimulate transcription of the cloned gene in an S-phase-dependent manner when introduced into somatic cells. The factors interacting with the two elements, CCAAT at -127 base pairs and octamer ATTTGCAT at -93 base pairs, interact with each other to bring about a maximum stimulation of S-phase-dependent transcription. The level of CCAAT and octamer-binding proteins is unchanged during the cell cycle, and the S-phase-dependent transcription of TH2B and endogenous mouse H2B genes does not require synthesis of new proteins during the S phase. Cell cycle-specific posttranslational modification of regulatory proteins may be responsible for the S-phase-dependent transcription of H2B histone genes. The biological significance of the presence of S-phase-specific transcription regulatory elements in the DNA replication-independent and tissue-specific TH2B gene is not known.

scholarly journals Expression of E1A in terminally differentiated muscle cells reactivates the cell cycle and suppresses tissue-specific genes by separable mechanisms.

1996 ◽  
Vol 16 (10) ◽  
pp. 5302-5312 ◽  
Author(s):  
M Tiainen ◽  
D Spitkovsky ◽  
P Jansen-Dürr ◽  
A Sacchi ◽  
M Crescenzi
Keyword(s):  
Cell Cycle ◽  
Kinase Inhibitor ◽  
Cyclin E ◽  
Muscle Cells ◽  
S Phase ◽  
Specific Gene ◽  
Muscle Creatine Kinase ◽  
Tissue Specific ◽  
Adenovirus E1a ◽  
Differentiated Cells

Terminally differentiated cells are characterized by permanent withdrawal from the cell cycle; they do not enter S phase even when stimulated by growth factors or retroviral oncogenes. We have shown, however, that the adenovirus E1A oncogene can reactivate the cell cycle in terminally differentiated cells. In this report, we describe the molecular events triggered by E1A in terminally differentiated skeletal muscle cells. We found that in myotubes infected with the adenovirus mutant dl520, 12S E1A bypasses the early G1 phase and activates the expression of late-G1 genes, such as the cyclin E and cyclin A genes, cdk2, PCNA, and B-myb. Of these, the cyclin E gene and cdk2 were significantly overexpressed in comparison with levels in proliferating, undifferentiated myoblasts. p130 and pRb were phosphorylated before the infected myotubes entered S phase, despite the high expression of the cyclin-dependent kinase inhibitor p21, and E2F was released. Our results suggest that one of the mechanisms that E1A uses to overcome the proliferative block of terminally differentiated cells involves coordinated overexpression of cyclin E and cdk2. Following E1A expression, the myogenic transcription factors MyoD and myogenin and the muscle-specific structural genes encoding muscle creatine kinase and myosin heavy chain were downregulated. The muscle regulatory factors were also silenced in myotubes infected with adenovirus E1A mutants incapable of reactivating the cell cycle in terminally differentiated muscle cells. Thus, the suppression of the differentiation program is not a consequence of cell cycle reactivation in myotubes, and it is induced by an independent mechanism. Our results show that E1A reactivates the cell cycle and suppresses tissue-specific gene expression in terminally differentiated muscle cells, thus causing dedifferentiation.

scholarly journals Characterization of the S-phase-specific transcription regulatory elements in a DNA replication-independent testis-specific H2B (TH2B) histone gene

1990 ◽  
Vol 10 (2) ◽  
pp. 585-592
Author(s):  
I W Hwang ◽  
K Lim ◽  
C B Chae
Keyword(s):  
Cell Cycle ◽  
Dna Replication ◽  
Biological Significance ◽  
Regulatory Elements ◽  
S Phase ◽  
Phase Cell ◽  
Dependent Manner ◽  
Base Pairs ◽  
Pachytene Spermatocytes ◽  
Cloned Gene

The testis-specific H2B histone (TH2B) gene is expressed in pachytene spermatocytes of meiotic prophase I during rat spermatogenesis. The TH2B RNA and histones are not synthesized in any other tissues, and the synthesis is independent of DNA replication. However, the cloned TH2B gene has two DNA sequence elements which stimulate transcription of the cloned gene in an S-phase-dependent manner when introduced into somatic cells. The factors interacting with the two elements, CCAAT at -127 base pairs and octamer ATTTGCAT at -93 base pairs, interact with each other to bring about a maximum stimulation of S-phase-dependent transcription. The level of CCAAT and octamer-binding proteins is unchanged during the cell cycle, and the S-phase-dependent transcription of TH2B and endogenous mouse H2B genes does not require synthesis of new proteins during the S phase. Cell cycle-specific posttranslational modification of regulatory proteins may be responsible for the S-phase-dependent transcription of H2B histone genes. The biological significance of the presence of S-phase-specific transcription regulatory elements in the DNA replication-independent and tissue-specific TH2B gene is not known.

Involvement of the p38 MAPK signaling pathway in S-phase cell-cycle arrest induced by Furazolidone in human hepatoma G2 cells

2012 ◽  
Vol 33 (12) ◽  
pp. 1500-1505 ◽  
Author(s):  
Yu Sun ◽  
Shusheng Tang ◽  
Xi Jin ◽  
Chaoming Zhang ◽  
Wenxia Zhao ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Arrest ◽  
Signaling Pathway ◽  
P38 Mapk ◽  
Mapk Signaling ◽  
S Phase ◽  
Mapk Signaling Pathway ◽  
Phase Cell ◽  
Human Hepatoma ◽  
Cycle Arrest

scholarly journals S-Phase Cell Cycle Arrest, Apoptosis, and Molecular Mechanisms of Aplasia Ras homolog Member I–Induced Human Ovarian Cancer SKOV3 Cell Lines

2014 ◽  
Vol 24 (4) ◽  
pp. 629-634 ◽  
Author(s):  
Qiaoying Zhu ◽  
Jianming Hu ◽  
Huijuan Meng ◽  
Yufei Shen ◽  
Jinhua Zhou ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Ovarian Cancer ◽  
Molecular Mechanisms ◽  
Significant Inhibition ◽  
S Phase ◽  
Phase Cell ◽  
Cell Cycle Distribution ◽  
Human Ovarian Cancer ◽  
Skov3 Cell ◽  
Skov3 Cells

ObjectiveAplasia Ras homolog member I (ARHI) is associated with human ovarian cancer (HOC) growth and proliferation; however, the mechanisms are unclear. The purpose of this study was to investigateARHIeffects in HOC SKOV3 cells.MethodsWe transfected SKOV3 cells with PIRES2-EGFP-ARHI and measured growth inhibition rates, cell cycle distribution, apoptosis rates, and expression of P-STAT3 (phosphorylated signal transduction and activators of transcription 3) and P-ERK (phosphorylated extracellular signal regulated protein kinase).ResultsOur data showed significant inhibition of growth, significantly increased S-phase arrest and apoptosis rates, and reduction of P-STAT3 and P-ERK1/2 expression levels.ConclusionsWe propose the mechanism may involveARHI-induced phosphorylation of ERK1/2 and STAT3 protein kinases, thereby blocking proliferation signaling pathways, to induce HOC SKOV3 apoptosis.

scholarly journals Cdc5L interacts with ATR and is required for the S‐phase cell‐cycle checkpoint

EMBO Reports ◽  
2009 ◽  
Vol 10 (9) ◽  
pp. 1029-1035 ◽  
Author(s):  
Nianxiang Zhang ◽  
Ramandeep Kaur ◽  
Shamima Akhter ◽  
Randy J Legerski
Keyword(s):  
Cell Cycle ◽  
S Phase ◽  
Cell Cycle Checkpoint ◽  
Phase Cell ◽  
Cycle Checkpoint

scholarly journals Xanthohumol Induces Growth Inhibition and Apoptosis in Ca Ski Human Cervical Cancer Cells

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Wai Kuan Yong ◽  
Sri Nurestri Abd Malek
Keyword(s):  
Cell Cycle ◽  
Cervical Cancer ◽  
Cancer Cells ◽  
Cancer Cell ◽  
Morphological Changes ◽  
S Phase ◽  
Phase Cell ◽  
Cervical Cancer Cell Line ◽  
Dependent Manner ◽  
Cervical Cancer Cells

We investigate induction of apoptosis by xanthohumol on Ca Ski cervical cancer cell line. Xanthohumol is a prenylated chalcone naturally found in hop plants, previously reported to be an effective anticancer agent in various cancer cell lines. The present study showed that xanthohumol was effective to inhibit proliferation of Ca Ski cells based on IC50values using sulforhodamine B (SRB) assay. Furthermore, cellular and nuclear morphological changes were observed in the cells using phase contrast microscopy and Hoechst/PI fluorescent staining. In addition, 48-hour long treatment with xanthohumol triggered externalization of phosphatidylserine, changes in mitochondrial membrane potential, and DNA fragmentation in the cells. Additionally, xanthohumol mediated S phase arrest in cell cycle analysis and increased activities of caspase-3, caspase-8, and caspase-9. On the other hand, Western blot analysis showed that the expression levels of cleaved PARP, p53, and AIF increased, while Bcl-2 and XIAP decreased in a dose-dependent manner. Taken together, these findings indicate that xanthohumol-induced cell death might involve intrinsic and extrinsic apoptotic pathways, as well as downregulation of XIAP, upregulation of p53 proteins, and S phase cell cycle arrest in Ca Ski cervical cancer cells. This work suggests that xanthohumol is a potent chemotherapeutic candidate for cervical cancer.

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