Deregulated expression of the RanBP1 gene alters cell cycle progression in murine fibroblasts

1997 ◽  
Vol 110 (19) ◽  
pp. 2345-2357 ◽  
Author(s):  
A. Battistoni ◽  
G. Guarguaglini ◽  
F. Degrassi ◽  
C. Pittoggi ◽  
A. Palena ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Dna Replication ◽  
Cell Cycle Progression ◽  
Protein Import ◽  
Proliferating Cells ◽  
Cycle Progression ◽  
Ran Gtpase ◽  
Genes Encoding ◽  
Active Transcription ◽  
Gtpase Cycle

RanBP1 is a molecular partner of the Ran GTPase, which is implicated in the control of several processes, including DNA replication, mitotic entry and exit, cell cycle progression, nuclear structure, protein import and RNA export. While most genes encoding Ran-interacting partners are constitutively active, transcription of the RanBP1 mRNA is repressed in non proliferating cells, is activated at the G1/S transition in cycling cells and peaks during S phase. We report here that forced expression of the RanBP1 gene disrupts the orderly execution of the cell division cycle at several stages, causing inhibition of DNA replication, defective mitotic exit and failure of chromatin decondensation during the telophase-to-interphase transition in cells that achieve nuclear duplication and chromosome segregation. These results suggest that deregulated RanBP1 activity interferes with the Ran GTPase cycle and prevents the functioning of the Ran signalling system during the cell cycle.

scholarly journals Separate domains of the Ran GTPase interact with different factors to regulate nuclear protein import and RNA processing.

1995 ◽  
Vol 15 (4) ◽  
pp. 2117-2124 ◽  
Author(s):  
M Ren ◽  
A Villamarin ◽  
A Shih ◽  
E Coutavas ◽  
M S Moore ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Progression ◽  
Protein Import ◽  
Nuclear Protein ◽  
Nucleotide Exchange ◽  
Cycle Progression ◽  
Ran Gtpase ◽  
Guanine Nucleotide Exchange ◽  
Nuclear Protein Import ◽  
Ran Gtp

The small Ras-related GTP binding and hydrolyzing protein Ran has been implicated in a variety of processes, including cell cycle progression, DNA synthesis, RNA processing, and nuclear-cytosolic trafficking of both RNA and proteins. Like other small GTPases, Ran appears to function as a switch: Ran-GTP and Ran-GDP levels are regulated both by guanine nucleotide exchange factors and GTPase activating proteins, and Ran-GTP and Ran-GDP interact differentially with one or more effectors. One such putative effector, Ran-binding protein 1 (RanBP1), interacts selectively with Ran-GTP. Ran proteins contain a diagnostic short, acidic, carboxyl-terminal domain, DEDDDL, which, at least in the case of human Ran, is required for its role in cell cycle regulation. We show here that this domain is required for the interaction between Ran and RanBP1 but not for the interaction between Ran and a Ran guanine nucleotide exchange factor or between Ran and a Ran GTPase activating protein. In addition, Ran lacking this carboxyl-terminal domain functions normally in an in vitro nuclear protein import assay. We also show that RanBP1 interacts with the mammalian homolog of yeast protein RNA1, a protein involved in RNA transport and processing. These results are consistent with the hypothesis that Ran functions directly in at least two pathways, one, dependent on RanBP1, that affects cell cycle progression and RNA export, and another, independent of RanBP1, that affects nuclear protein import.

scholarly journals Regulation of Cell Division in Bacteria by Monitoring Genome Integrity and DNA Replication Status

2019 ◽  
Vol 202 (2) ◽  
Author(s):  
Peter E. Burby ◽  
Lyle A. Simmons
Keyword(s):  
Cell Cycle ◽  
Dna Damage ◽  
Cell Division ◽  
Dna Replication ◽  
Cell Cycle Progression ◽  
Genome Instability ◽  
Sos Response ◽  
Bacterial Cells ◽  
Cycle Progression ◽  
Content Type

ABSTRACT All organisms regulate cell cycle progression by coordinating cell division with DNA replication status. In eukaryotes, DNA damage or problems with replication fork progression induce the DNA damage response (DDR), causing cyclin-dependent kinases to remain active, preventing further cell cycle progression until replication and repair are complete. In bacteria, cell division is coordinated with chromosome segregation, preventing cell division ring formation over the nucleoid in a process termed nucleoid occlusion. In addition to nucleoid occlusion, bacteria induce the SOS response after replication forks encounter DNA damage or impediments that slow or block their progression. During SOS induction, Escherichia coli expresses a cytoplasmic protein, SulA, that inhibits cell division by directly binding FtsZ. After the SOS response is turned off, SulA is degraded by Lon protease, allowing for cell division to resume. Recently, it has become clear that SulA is restricted to bacteria closely related to E. coli and that most bacteria enforce the DNA damage checkpoint by expressing a small integral membrane protein. Resumption of cell division is then mediated by membrane-bound proteases that cleave the cell division inhibitor. Further, many bacterial cells have mechanisms to inhibit cell division that are regulated independently from the canonical LexA-mediated SOS response. In this review, we discuss several pathways used by bacteria to prevent cell division from occurring when genome instability is detected or before the chromosome has been fully replicated and segregated.

The murine Ki-67 cell proliferation antigen accumulates in the nucleolar and heterochromatic regions of interphase cells and at the periphery of the mitotic chromosomes in a process essential for cell cycle progression

1996 ◽  
Vol 109 (1) ◽  
pp. 143-153 ◽  
Author(s):  
M. Starborg ◽  
K. Gell ◽  
E. Brundell ◽  
C. Hoog
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Progression ◽  
Tandem Repeats ◽  
Sequence Motifs ◽  
Mitotic Chromosomes ◽  
Proliferating Cells ◽  
Ki 67 ◽  
Cycle Progression ◽  
Conserved Sequence ◽  
Interphase Cells

We have isolated the murine homologue of the human Ki-67 antigen. The Ki-67 antigen is used as a marker to assess the proliferative capacity of tumour cells; however, its cellular function is not known. The murine Ki-67 cDNA sequence (TSG126) was found to contain 13 tandem repeats, making up more than half of the total protein size. A comparison of this repetitive sequence block to its human counterpart, which contains 16 consecutive repeat units, revealed several conserved sequence motifs, including one motif frequently observed in proteins interacting with DNA. An antiserum developed against the product of the TSG126 cDNA clone identified a protein with an apparent molecular mass of 360 kDa, mainly expressed in proliferating cells. The TSG126 protein begins to accumulate during the late G1 stage of the cell cycle and is first seen as numerous small granules evenly distributed throughout the nucleus. During the S and the G2 phases, larger foci that overlap with the nucleoli and the heterochromatic regions are formed. At the onset of mitosis the TSG126 protein undergoes a dramatic redistribution process and becomes associated with the surface of the condensed chromosomes. The relative absence of the TSG126 protein from G1 interphase cells strongly argues against a model where the association of the TSG126 protein with mitotic chromosomes merely reflects a mechanism for the symmetrical distribution of nucleolar proteins between daughter cells. Instead, the intracellular distribution of the TSG126 protein during the cell cycle suggests that it could have a chromatin-associated function in both interphase and mitotic cells. Microinjection of anti-TSG126 antibodies into proliferating Swiss-3T3 fibroblasts was found to delay cell cycle progression, indicating that the TSG126 protein has an essential nuclear function.

scholarly journals Molecular cloning of a novel mitogen-inducible nuclear protein with a Ran GTPase-activating domain that affects cell cycle progression.

1995 ◽  
Vol 15 (1) ◽  
pp. 552-560 ◽  
Author(s):  
M Hattori ◽  
N Tsukamoto ◽  
M S Nur-e-Kamal ◽  
B Rubinfeld ◽  
K Iwai ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Progression ◽  
Nuclear Protein ◽  
Interleukin 2 ◽  
Quiescent State ◽  
Cycle Progression ◽  
Ran Gtpase ◽  
G0 Phase ◽  
Nih 3T3

We have cloned a novel cDNA (Spa-1) which is little expressed in the quiescent state but induced in the interleukin 2-stimulated cycling state of an interleukin 2-responsive murine lymphoid cell line by differential hybridization. Spa-1 mRNA (3.5 kb) was induced in normal lymphocytes following various types of mitogenic stimulation. In normal organs it is preferentially expressed in both fetal and adult lymphohematopoietic tissues. A Spa-1-encoded protein of 68 kDa is localized mostly in the nucleus. Its N-terminal domain is highly homologous to a human Rap1 GTPase-activating protein (GAP), and a fusion protein of this domain (SpanN) indeed exhibited GAP activity for Rap1/Rsr1 but not for Ras or Rho in vitro. Unlike the human Rap1 GAP, however, SpanN also exhibited GAP activity for Ran, so far the only known Ras-related GTPase in the nucleus. In the presence of serum, stable Spa-1 cDNA transfectants of NIH 3T3 cells (NIH/Spa-1) hardly overexpressed Spa-1 (p68), and they grew as normally as did the parental cells. When NIH/Spa-1 cells were serum starved to be arrested in the G1/G0 phase of the cell cycle, however, they, unlike the control cells, exhibited progressive Spa-1 p68 accumulation, and following the addition of serum they showed cell death resembling mitotic catastrophes of the S phase during cell cycle progression. The results indicate that the novel nuclear protein Spa-1, with a potentially active Ran GAP domain, severely hampers the mitogen-induced cell cycle progression when abnormally and/or prematurely expressed. Functions of the Spa-1 protein and its regulation are discussed in the context of its possible interaction with the Ran/RCC-1 system, which is involved in the coordinated nuclear functions, including cell division.

scholarly journals The Saccharomyces cerevisiae Anaphase-Promoting Complex Interacts with Multiple Histone-Modifying Enzymes To Regulate Cell Cycle Progression

2010 ◽  
Vol 9 (10) ◽  
pp. 1418-1431 ◽  
Author(s):  
Emma L. Turner ◽  
Mackenzie E. Malo ◽  
Marnie G. Pisclevich ◽  
Megan D. Dash ◽  
Gerald F. Davies ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Progression ◽  
Chromatin Assembly ◽  
Temperature Sensitive ◽  
Anaphase Promoting Complex ◽  
Cycle Progression ◽  
Ubiquitin Ligase Complex ◽  
Genes Encoding ◽  
Dependent Cell ◽  
Histone Modifying Enzymes

ABSTRACT The anaphase-promoting complex (APC), a large evolutionarily conserved ubiquitin ligase complex, regulates cell cycle progression through mitosis and G1. Here, we present data suggesting that APC-dependent cell cycle progression relies on a specific set of posttranslational histone-modifying enzymes. Multiple APC subunit mutants were impaired in total and modified histone H3 protein content. Acetylated H3K56 (H3K56Ac) levels were as reduced as those of total H3, indicating that loading histones with H3K56Ac is unaffected in APC mutants. However, under restrictive conditions, H3K9Ac and dimethylated H3K79 (H3K79me2) levels were more greatly reduced than those of total H3. In a screen for histone acetyltransferase (HAT) and histone deacetylase (HDAC) mutants that genetically interact with the apc5 CA (chromatin assembly) mutant, we found that deletion of GCN5 or ELP3 severely hampered apc5 CA temperature-sensitive (ts) growth. Further analyses showed that (i) the elp3Δ gcn5Δ double mutant ts defect was epistatic to that observed in apc5 CA cells; (ii) gcn5Δ and elp3Δ mutants accumulate in mitosis; and (iii) turnover of the APC substrate Clb2 is not impaired in elp3Δ gcn5Δ cells. Increased expression of ELP3 and GCN5, as well as genes encoding the HAT Rtt109 and the chromatin assembly factors Msi1 and Asf1, suppressed apc5 CA defects, while increased APC5 expression partially suppressed elp3Δ gcn5Δ growth defects. Finally, we demonstrate that Gcn5 is unstable during G1 and following G1 arrest and is stabilized in APC mutants. We present our working model in which Elp3/Gcn5 and the APC work together to facilitate passage through mitosis and G1. To progress into S, we propose that at least Gcn5 must then be targeted for degradation in an APC-dependent fashion.

scholarly journals Microarray gene expression profiling in colorectal (HCT116) and hepatocellular (HepG2) carcinoma cell lines treated withMelicope ptelefolialeaf extract reveals transcriptome profiles exhibiting anticancer activity

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5203 ◽  
Author(s):  
Mohammad Faujul Kabir ◽  
Johari Mohd Ali ◽  
Onn Haji Hashim
Keyword(s):  
Gene Expression ◽  
Cell Cycle ◽  
Dna Replication ◽  
Cell Lines ◽  
Microarray Data ◽  
Expression Profiling ◽  
Cell Cycle Progression ◽  
Anticancer Activities ◽  
Microarray Gene Expression ◽  
Cycle Progression

BackgroundWe have previously reported anticancer activities ofMelicope ptelefolia(MP) leaf extracts on four different cancer cell lines. However, the underlying mechanisms of actions have yet to be deciphered. In the present study, the anticancer activity of MP hexane extract (MP-HX) on colorectal (HCT116) and hepatocellular carcinoma (HepG2) cell lines was characterized through microarray gene expression profiling.MethodsHCT116 and HepG2 cells were treated with MP-HX for 24 hr. Total RNA was extracted from the cells and used for transcriptome profiling using Applied Biosystem GeneChip™ Human Gene 2.0 ST Array. Gene expression data was analysed using an Applied Biosystems Expression Console and Transcriptome Analysis Console software. Pathway enrichment analyses was performed using Ingenuity Pathway Analysis (IPA) software. The microarray data was validated by profiling the expression of 17 genes through quantitative reverse transcription PCR (RT-qPCR).ResultsMP-HX induced differential expression of 1,290 and 1,325 genes in HCT116 and HepG2 cells, respectively (microarray data fold change, MA_FC ≥ ±2.0). The direction of gene expression change for the 17 genes assayed through RT-qPCR agree with the microarray data. In both cell lines, MP-HX modulated the expression of many genes in directions that support antiproliferative activity. IPA software analyses revealed MP-HX modulated canonical pathways, networks and biological processes that are associated with cell cycle, DNA replication, cellular growth and cell proliferation. In both cell lines, upregulation of genes which promote apoptosis, cell cycle arrest and growth inhibition were observed, while genes that are typically overexpressed in diverse human cancers or those that promoted cell cycle progression, DNA replication and cellular proliferation were downregulated. Some of the genes upregulated by MP-HX include pro-apoptotic genes (DDIT3, BBC3, JUN), cell cycle arresting (CDKN1A, CDKN2B), growth arrest/repair (TP53, GADD45A) and metastasis suppression (NDRG1). MP-HX downregulated the expression of genes that could promote anti-apoptotic effect, cell cycle progression, tumor development and progression, which include BIRC5, CCNA2, CCNB1, CCNB2, CCNE2, CDK1/2/6, GINS2, HELLS, MCM2/10 PLK1, RRM2 and SKP2. It is interesting to note that all six top-ranked genes proposed to be cancer-associated (PLK1, MCM2, MCM3, MCM7, MCM10 and SKP2) were downregulated by MP-HX in both cell lines.DiscussionThe present study showed that the anticancer activities of MP-HX are exerted through its actions on genes regulating apoptosis, cell proliferation, DNA replication and cell cycle progression. These findings further project the potential use of MP as a nutraceutical agent for cancer therapeutics.

scholarly journals Evidence for a dual role for TC4 protein in regulating nuclear structure and cell cycle progression.

1994 ◽  
Vol 125 (4) ◽  
pp. 705-719 ◽  
Author(s):  
S Kornbluth ◽  
M Dasso ◽  
J Newport
Keyword(s):  
Cell Cycle ◽  
Dna Replication ◽  
Nuclear Structure ◽  
Cell Cycle Progression ◽  
Cycle Progression ◽  
Nuclear Assembly ◽  
Egg Extracts ◽  
A Cell ◽  
Xenopus Egg Extracts

TC4, a ras-like G protein, has been implicated in the feedback pathway linking the onset of mitosis to the completion of DNA replication. In this report we find distinct roles for TC4 in both nuclear assembly and cell cycle progression. Mutant and wild-type forms of TC4 were added to Xenopus egg extracts capable of assembling nuclei around chromatin templates in vitro. We found that a mutant TC4 protein defective in GTP binding (GDP-bound form) suppressed nuclear growth and prevented DNA replication. Nuclear transport under these conditions approximated normal levels. In a separate set of experiments using a cell-free extract of Xenopus eggs that cycles between S and M phases, the GDP-bound form of TC4 had dramatic effects, blocking entry into mitosis even in the complete absence of nuclei. The effect of this mutant TC4 protein on cell cycle progression is mediated by phosphorylation of p34cdc2 on tyrosine and threonine residues, negatively regulating cdc2 kinase activity. Therefore, we provide direct biochemical evidence for a role of TC4 in both maintaining nuclear structure and in the signaling pathways that regulate entry into mitosis.

scholarly journals Identification of DHX9 as a cell cycle regulated nucleolar recruitment factor for CIZ1

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Urvi Thacker ◽  
Tekle Pauzaite ◽  
James Tollitt ◽  
Maria Twardowska ◽  
Charlotte Harrison ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Dna Replication ◽  
Cell Cycle Progression ◽  
Zinc Finger Protein ◽  
S Phase ◽  
Cycle Progression ◽  
Inactive X Chromosome ◽  
Functional Characterisation ◽  
Interaction Partners

Abstract CIP1-interacting zinc finger protein 1 (CIZ1) is a nuclear matrix associated protein that facilitates a number of nuclear functions including initiation of DNA replication, epigenetic maintenance and associates with the inactive X-chromosome. Here, to gain more insight into the protein networks that underpin this diverse functionality, molecular panning and mass spectrometry are used to identify protein interaction partners of CIZ1, and CIZ1 replication domain (CIZ1-RD). STRING analysis of CIZ1 interaction partners identified 2 functional clusters: ribosomal subunits and nucleolar proteins including the DEAD box helicases, DHX9, DDX5 and DDX17. DHX9 shares common functions with CIZ1, including interaction with XIST long-non-coding RNA, epigenetic maintenance and regulation of DNA replication. Functional characterisation of the CIZ1-DHX9 complex showed that CIZ1-DHX9 interact in vitro and dynamically colocalise within the nucleolus from early to mid S-phase. CIZ1-DHX9 nucleolar colocalisation is dependent upon RNA polymerase I activity and is abolished by depletion of DHX9. In addition, depletion of DHX9 reduced cell cycle progression from G1 to S-phase in mouse fibroblasts. The data suggest that DHX9-CIZ1 are required for efficient cell cycle progression at the G1/S transition and that nucleolar recruitment is integral to their mechanism of action.

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