The role of RBF in developmentally regulated cell proliferation in the eye disc and in Cyclin D/Cdk4 induced cellular growth

Development ◽  
2002 ◽  
Vol 129 (6) ◽  
pp. 1345-1356 ◽  
Author(s):  
Shijie Xin ◽  
Li Weng ◽  
Jinhua Xu ◽  
Wei Du
Keyword(s):  
Cell Proliferation ◽  
Eye Development ◽  
S Phase ◽  
Cellular Growth ◽  
Mutant Form ◽  
Cyclin D ◽  
Mitotic Wave ◽  
Eye Disc ◽  
Disc Cells

During Drosophila eye development, cell proliferation is coordinated with differentiation. Immediately posterior to the morphogenetic furrow, cells enter a synchronous round of S phase called second mitotic wave. We have examined the role of RBF, the Drosophila RB family homolog, in cell cycle progression in the second mitotic wave. RBF-280, a mutant form of RBF that has four putative cdk phosphorylation sites mutated, can no longer be regulated by Cyclin D or Cyclin E. Expression of RBF-280 in the developing eye revealed that RBF-280 does not inhibit G1/S transition in the second mitotic wave, rather it delays the completion of S phase and leads to abnormal eye development. These observations suggest that RB/E2F control the rate of S-phase progression instead of G1/S transition in the second mitotic wave. Characterization of the role of RBF in Cyclin D/Cdk4-mediated cellular growth showed that RBF-280 blocks Cyclin D/Cdk4 induced cellular growth in the proliferating wing disc cells but not in the non-dividing eye disc cells. By contrast, RBF-280 does not block activated Ras-induced cellular growth. These results suggest that the ability of Cyclin D/Cdk4 to drive growth in the proliferating wing cells is distinct from that in the none-dividing eye cells or the ability of activated Ras to induce growth, and that RBF may have a role in regulating growth in the proliferating wing discs.

scholarly journals Role of Serotonin Transporter in Eye Development of Drosophila melanogaster

2020 ◽  
Vol 21 (11) ◽  
pp. 4086
Author(s):  
Tuan L. A. Pham ◽  
Tran Duy Binh ◽  
Guanchen Liu ◽  
Thanh Q. C. Nguyen ◽  
Yen D. H. Nguyen ◽  
...  
Keyword(s):  
Cell Death ◽  
Drosophila Melanogaster ◽  
Serotonin Transporter ◽  
Compound Eye ◽  
Eye Development ◽  
S Phase ◽  
Eye Disc ◽  
Eye Imaginal Disc ◽  
The Brain

Serotonin transporter (SerT) in the brain is an important neurotransmitter transporter involved in mental health. However, its role in peripheral organs is poorly understood. In this study, we investigated the function of SerT in the development of the compound eye in Drosophila melanogaster. We found that SerT knockdown led to excessive cell death and an increased number of cells in S-phase in the posterior eye imaginal disc. Furthermore, the knockdown of SerT in the eye disc suppressed the activation of Akt, and the introduction of PI3K effectively rescued this phenotype. These results suggested that SerT plays a role in the healthy eye development of D. melanogaster by controlling cell death through the regulation of the PI3K/Akt pathway.

scholarly journals Cytosolic Ras Supports Eye Development in Drosophila

2010 ◽  
Vol 30 (24) ◽  
pp. 5649-5657 ◽  
Author(s):  
Pamela J. Sung ◽  
Aloma B. Rodrigues ◽  
Andrew Kleinberger ◽  
Steven Quatela ◽  
Erika A. Bach ◽  
...  
Keyword(s):  
Posttranslational Modifications ◽  
Eye Development ◽  
Mapk Signaling ◽  
Mitogen Activated Protein Kinase ◽  
Membrane Association ◽  
Ras Proteins ◽  
Eye Disc ◽  
Mosaic Analysis ◽  
Mitogen Activated Protein ◽  
Disc Cells

ABSTRACT Ras proteins associate with cellular membranes as a consequence of a series of posttranslational modifications of a C-terminal CAAX sequence that include prenylation and are thought to be required for biological activity. In Drosophila melanogaster, Ras1 is required for eye development. We found that Drosophila Ras1 is inefficiently prenylated as a consequence of a lysine in the A1 position of its CAAX sequence such that a significant pool remains soluble in the cytosol. We used mosaic analysis with a repressible cell marker (MARCM) to assess if various Ras1 transgenes could restore photoreceptor fate to eye disc cells that are null for Ras1. Surprisingly, we found that whereas Ras1 with an enhanced efficiency of membrane targeting could not rescue the Ras1 null phenotype, Ras1 that was not at all membrane targeted by virtue of a mutation of the CAAX cysteine was able to fully rescue eye development. In addition, constitutively active Ras112V,C186S not targeted to membranes produced a hypermorphic phenotype and stimulated mitogen-activated protein kinase (MAPK) signaling in S2 cells. We conclude that the membrane association of Drosophila Ras1 is not required for eye development.

scholarly journals MiRNA-144-3p inhibits high glucose induced cell proliferation through suppressing FGF16

2019 ◽  
Vol 39 (7) ◽  
Author(s):  
Cuimin Chen ◽  
Chunyan Zhao ◽  
Cao Gu ◽  
Xiao Cui ◽  
Jinhui Wu
Keyword(s):  
Cell Proliferation ◽  
High Glucose ◽  
Developed Countries ◽  
Mapk Signaling ◽  
S Phase ◽  
Luciferase Reporter ◽  
Direct Target ◽  
The Developed Countries ◽  
Western Blotting Assay

Abstract As a major cause of blindness, diabetic retinopathy (DR) is often found in the developed countries. Our previous study identified a down-regulated miRNA: miR-144-3p in response to hyperglycemia. The present study aims to investigate the role of miR-144-3p in proliferation of microvascular epithelial cells. Endothelial cells were treated with different concentrations of glucose, after which miR-144-3p were detected with real-time PCR assay. MiR-144-3p mimics or inhibitors were used to increase or knockdown the level of this miRNA. Western blotting assay and ELISA assay were used to measure the expression and concentration of VEGF protein. 5-Bromo-2-deoxyUridine (BrdU) labeled cell cycle assay was used to detect cells in S phase. MiRNA targets were predicted by using a TargetScan tool, and were further verified by luciferase reporter assay. In the present study, we focussed on a significantly down-regulated miRNA, miR-144-3p, and investigated its role in high glucose (HG) induced cell proliferation. Our data showed that miR-144-3p mimics significantly inhibited HG induced cell proliferation and reduced the percentage of cells in S phase. HG induced up-regulation of VEGF was also prohibited by miR-144-3p mimics. Through wound-healing assay, we found that miR-144-3p suppressed cell migration after HG treatments. Moreover, we predicted and proved that fibroblast growth factor (FGF)16 is a direct target of miR-144-3p. Finally, miR-144-3p attenuated HG induced MAPK activation. In conclusion, we demonstrated that miR-144-3p inhibited high glucose-induced cell proliferation through suppressing FGF16 and MAPK signaling pathway, suggesting a possible role of miR-144-FGF16 in the development of DR.

Role of the p53 protein in cell proliferation as studied by microinjection of monoclonal antibodies

1984 ◽  
Vol 4 (2) ◽  
pp. 276-281
Author(s):  
W E Mercer ◽  
C Avignolo ◽  
R Baserga
Keyword(s):  
Cell Proliferation ◽  
Monoclonal Antibodies ◽  
Mammalian Cells ◽  
P53 Protein ◽  
S Phase ◽  
Human Cells ◽  
Antigenic Determinants ◽  
3T3 Cells ◽  
Species Specific

Two monoclonal antibodies against the p53 protein, PAb 122 and 200-47, were microinjected into mammalian cells as a probe to determine the role of the p53 protein in cell proliferation. PAb 122 recognizes the p53 proteins of mouse and human cells but not of hamster cells, whereas 200-47 recognizes the p53 proteins of mouse and hamster cells but not of human cells. The ability of these antibodies to inhibit serum-stimulated DNA synthesis of cells in culture correlates with their ability to recognize the species-specific antigenic determinants. More important, however, is the observation that microinjected PAb 122 inhibits the transition of Swiss 3T3 cells from G0 to S phase, but has no effect on the progression of these cells from mitosis to the S phase.

Drosophila homologues of the transcriptional coactivation complex subunits TRAP240 and TRAP230 are required for identical processes in eye-antennal disc development

Development ◽  
2001 ◽  
Vol 128 (4) ◽  
pp. 603-615 ◽  
Author(s):  
J. Treisman
Keyword(s):  
Cell Proliferation ◽  
Notch Signaling ◽  
Hedgehog Signaling ◽  
Blind Spot ◽  
Mediator Complex ◽  
Eye Disc ◽  
Disc Cells ◽  
Inappropriate Expression ◽  
Mutant Cells ◽  
Antennal Disc

We have identified mutations in two genes, blind spot and kohtalo, that encode Drosophila homologues of human TRAP240 and TRAP230, components of a large transcriptional coactivation complex homologous to the yeast Mediator complex. Loss of either blind spot or kohtalo has identical effects on the development of the eye-antennal disc. Eye disc cells mutant for either gene can express decapentaplegic and atonal in response to Hedgehog signaling, but they maintain inappropriate expression of these genes and fail to differentiate further. Mutant cells in the antennal disc lose expression of Distal-less and misexpress eyeless, suggesting a partial transformation towards the eye fate. blind spot and kohtalo are not required for cell proliferation or survival, and their absence cannot be rescued by activation of the Hedgehog or Notch signaling pathways. These novel and specific phenotypes suggest that TRAP240 and TRAP230 act in concert to mediate an unknown developmental signal or a combination of signals.

scholarly journals Role of the p53 protein in cell proliferation as studied by microinjection of monoclonal antibodies.

1984 ◽  
Vol 4 (2) ◽  
pp. 276-281 ◽  
Author(s):  
W E Mercer ◽  
C Avignolo ◽  
R Baserga
Keyword(s):  
Cell Proliferation ◽  
Monoclonal Antibodies ◽  
Mammalian Cells ◽  
P53 Protein ◽  
S Phase ◽  
Human Cells ◽  
Antigenic Determinants ◽  
3T3 Cells ◽  
Species Specific

Two monoclonal antibodies against the p53 protein, PAb 122 and 200-47, were microinjected into mammalian cells as a probe to determine the role of the p53 protein in cell proliferation. PAb 122 recognizes the p53 proteins of mouse and human cells but not of hamster cells, whereas 200-47 recognizes the p53 proteins of mouse and hamster cells but not of human cells. The ability of these antibodies to inhibit serum-stimulated DNA synthesis of cells in culture correlates with their ability to recognize the species-specific antigenic determinants. More important, however, is the observation that microinjected PAb 122 inhibits the transition of Swiss 3T3 cells from G0 to S phase, but has no effect on the progression of these cells from mitosis to the S phase.

scholarly journals Involvement of the STAT5-cyclin D/CDK4-pRb pathway in β-cell proliferation stimulated by prolactin during pregnancy

2019 ◽  
Vol 316 (1) ◽  
pp. E135-E144 ◽  
Author(s):  
Xin Zhao ◽  
Yili Xu ◽  
Ya Wu ◽  
Hui Zhang ◽  
Houxia Shi ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Cell Cycle Progression ◽  
Cell Mass ◽  
Cyclin D ◽  
Β Cell ◽  
Cycle Progression ◽  
Rb Phosphorylation ◽  
Insulinoma Cells

During pregnancy, maternal pancreatic β-cells undergo a compensatory expansion in response to the state of insulin resistance, where prolactin (PRL) plays a major role. Retinoblastoma protein (Rb) has been shown to critically regulate islet proliferation and function. The aim of the study was to explore the role of Rb in β-cell mass expansion during pregnancy. Expression of pocket protein family and E2Fs were examined in mouse islets during pregnancy and in insulinoma cells (INS-1) stimulated by PRL. PRL-stimulated INS-1 cells were used to explore the signaling pathway that regulates Rb downstream of the PRL receptor. Pancreas-specific Rb-knockout (Rb-KO) mice were assessed to evaluate the in vivo function of Rb in β-cell proliferation during pregnancy. During pregnancy, expression of Rb, phospho-Rb (p-Rb), p107, and E2F1 increased, while p130 decreased in maternal islets. With PRL stimulation, induction of Rb expression occurred mainly in the nucleus, while p-Rb was predominantly in the cytoplasm. Inhibition of STAT5 significantly restrained the expression of CDK4, Rb, p-Rb, and E2F1 in PRL-stimulated INS-1 cells with attenuation in cell cycle progression. Reduction of Rb phosphorylation by CDK4 inhibition blocked PRL-mediated proliferation of INS-1 cells. On the other hand, knockdown of Rb using siRNA led to an induction in E2F1 leading to cell cycle progression from G1 to S and G2/M phase, similar to the effects of PRL-mediated induction of p-Rb that led to cell proliferation. With Rb knockdown, PRL did not lead to further increase in cell cycle progression. Similarly, while Rb-KO pregnant mice displayed better glucose tolerance and higher insulin secretion, they had similar β-cell mass and proliferation to wild-type pregnant controls, supporting the essential role of Rb suppression in augmenting β-cell proliferation during pregnancy. Rb-E2F1 regulation plays a pivotal role in PRL-stimulated β-cell proliferation. PRL promotes Rb phosphorylation and E2F1 upregulation via STAT5-cyclin D/CDK4 pathway during pregnancy.

On the role of TRPC1 in control of Ca2+ influx, cell volume, and cell cycle

2012 ◽  
Vol 303 (6) ◽  
pp. C625-C634 ◽  
Author(s):  
C. P. Madsen ◽  
T. K. Klausen ◽  
A. Fabian ◽  
B. J. Hansen ◽  
S. F. Pedersen ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Cell Volume ◽  
Volume Regulation ◽  
Cell Cycle Progression ◽  
Regulatory Volume Decrease ◽  
Cell Volume Regulation ◽  
S Phase ◽  
Cycle Progression

Ca+ signaling plays a crucial role in control of cell cycle progression, but the understanding of the dynamics of Ca2+ influx and release of Ca2+ from intracellular stores during the cell cycle is far from complete. The aim of the present study was to investigate the role of the free extracellular Ca2+ concentration ([Ca2+]o) in cell proliferation, the pattern of changes in the free intracellular Ca2+ concentration ([Ca2+]i) during cell cycle progression, and the role of the transient receptor potential (TRP)C1 in these changes as well as in cell cycle progression and cell volume regulation. In Ehrlich Lettré Ascites (ELA) cells, [Ca2+]i decreased significantly, and the thapsigargin-releasable Ca2+ pool in the intracellular stores increased in G1 as compared with G0. Store-depletion-operated Ca2+ entry (SOCE) and TRPC1 protein expression level were both higher in G1 than in G0 and S phase, in parallel with a more effective volume regulation after swelling [regulatory volume decrease (RVD)] in G1 as compared with S phase. Furthermore, reduction of [Ca2+]o, as well as two unspecific SOCE inhibitors, 2-APB (2-aminoethyldiphenyl borinate) and SKF96365 (1-(β-[3-(4-methoxy-phenyl)propoxyl-4-methoxyphenethyl)1H-imidazole-hydrochloride), inhibited ELA cell proliferation. Finally, Madin-Darby canine kidney cells in which TRPC1 was stably silenced [TRPC1 knockdown (TRPC1-KD) MDCK] exhibited reduced SOCE, slower RVD, and reduced cell proliferation compared with mock controls. In conclusion, in ELA cells, SOCE and TRPC1 both seem to be upregulated in G1 as compared with S phase, concomitant with an increased rate of RVD. Furthermore, TRPC1-KD MDCK cells exhibit decreased SOCE, decreased RVD, and decreased proliferation, suggesting that, at least in certain cell types, TRPC1 is regulated during cell cycle progression and is involved in SOCE, RVD, and cell proliferation.

scholarly journals The S-phase-induced lncRNA SUNO1 promotes cell proliferation by controlling YAP1/Hippo signaling pathway

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Qinyu Hao ◽  
Xinying Zong ◽  
Qinyu Sun ◽  
Yo-Chuen Lin ◽  
You Jin Song ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Rna Polymerase Ii ◽  
Cell Cycle Progression ◽  
S Phase ◽  
Cancer Prognosis ◽  
Cycle Phase ◽  
Hippo Signaling ◽  
Cycle Progression

Cell cycle is a cellular process that is subject to stringent control. In contrast to the wealth of knowledge of proteins controlling the cell cycle, very little is known about the molecular role of lncRNAs (long noncoding RNAs) in cell-cycle progression. By performing genome-wide transcriptome analyses in cell-cycle-synchronized cells, we observed cell-cycle phase-specific induction of >2000 lncRNAs. Further, we demonstrate that an S-phase-upregulated lncRNA, SUNO1, facilitates cell-cycle progression by promoting YAP1-mediated gene expression. SUNO1 facilitates the cell-cycle-specific transcription of WTIP, a positive regulator of YAP1, by promoting the co-activator, DDX5-mediated stabilization of RNA polymerase II on chromatin. Finally, elevated SUNO1 levels are associated with poor cancer prognosis and tumorigenicity, implying its pro-survival role. Thus, we demonstrate the role of a S-phase up-regulated lncRNA in cell-cycle progression via modulating the expression of genes controlling cell proliferation.

scholarly journals Role of Plk2 (Snk) in Mouse Development and Cell Proliferation

2003 ◽  
Vol 23 (19) ◽  
pp. 6936-6943 ◽  
Author(s):  
Sheng Ma ◽  
Jean Charron ◽  
Raymond L. Erikson
Keyword(s):  
Cell Proliferation ◽  
Hippocampal Neurons ◽  
Cultured Cells ◽  
Skeletal Development ◽  
Postnatal Growth ◽  
S Phase ◽  
Mouse Development ◽  
Embryonic Fibroblasts ◽  
Delayed Entry

ABSTRACT Plk2 (Snk) is a polo-like kinase expressed at G1 in cultured cells and mainly in the hippocampal neurons in the brains of adult rodents, but its function is poorly understood. We have generated mice deficient in Plk2 by gene targeting. Although Plk2 is not required for postnatal growth, Plk2−/− embryos show retarded growth and skeletal development late in gestation. The labyrinthine zone of the placenta is diminished in Plk2−/− embryos due to decreased cell proliferation. Cultured Plk2−/− embryonic fibroblasts grow more slowly than normal cells and show delayed entry into S phase. These data suggest a role for Plk2 in the cell cycle.

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