scholarly journals ERK1c regulates Golgi fragmentation during mitosis

2006 ◽  
Vol 172 (6) ◽  
pp. 885-897 ◽  
Author(s):  
Yoav D. Shaul ◽  
Rony Seger
Keyword(s):  
Small Interfering Rna ◽  
Cell Cycle Regulation ◽  
Mitotic Progression ◽  
Extracellular Signal Regulated Kinase ◽  
Extracellular Signal ◽  
Alternatively Spliced ◽  
Golgi Fragmentation ◽  
Cycle Regulation ◽  
Interfering Rna ◽  
Expression And Activity

Extracellular signal-regulated kinase 1c (ERK1c) is an alternatively spliced form of ERK1 that is regulated differently than other ERK isoforms. We studied the Golgi functions of ERK1c and found that it plays a role in MEK-induced mitotic Golgi fragmentation. Thus, in late G2 and mitosis of synchronized cells, the expression and activity of ERK1c was increased and it colocalized mainly with Golgi markers. Small interfering RNA of ERK1c significantly attenuated, whereas ERK1c overexpression facilitated, mitotic Golgi fragmentation. These effects were also reflected in mitotic progression, indicating that ERK1c is involved in cell cycle regulation via modulation of Golgi fragmentation. Although ERK1 was activated in mitosis as well, it could not replace ERK1c in regulating Golgi fragmentation. Therefore, MEKs regulate mitosis via all three ERK isoforms, where ERK1c acts specifically in the Golgi, whereas ERK1 and 2 regulate other mitosis-related processes. Thus, ERK1c extends the specificity of the Ras-MEK cascade by activating ERK1/2-independent processes.

scholarly journals Transcriptional Cross Talk between the Forkhead Transcription Factor Forkhead Box O1A and the Progesterone Receptor Coordinates Cell Cycle Regulation and Differentiation in Human Endometrial Stromal Cells

2007 ◽  
Vol 21 (10) ◽  
pp. 2334-2349 ◽  
Author(s):  
Masashi Takano ◽  
Zhenxiao Lu ◽  
Tomoko Goto ◽  
Luca Fusi ◽  
Jenny Higham ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Progesterone Receptor ◽  
Stromal Cells ◽  
Small Interfering Rna ◽  
Cell Cycle Regulation ◽  
Forkhead Transcription Factor ◽  
Endometrial Stromal Cells ◽  
Forkhead Box ◽  
Cycle Regulation ◽  
Interfering Rna

Abstract Differentiation of human endometrial stromal cells (HESCs) into decidual cells is associated with induction of the forkhead transcription factor forkhead box O1A (FOXO1). We performed a genomic screen to identify decidua-specific genes under FOXO1 control. Primary HESCs were transfected with small interfering RNA targeting FOXO1 or with nontargeting control small interfering RNA before treatment with a cAMP analogue and the progestin, medroxyprogesterone acetate for 72 h. Total RNA was processed for whole genome analysis using high-density oligonucleotide arrays. We identified 3405 significantly regulated genes upon decidualization of HESCs, 507 (15.3%) of which were aberrantly expressed upon FOXO1 knockdown. Among the most up-regulated FOXO1-dependent transcriptional targets were WNT signaling-related genes (WNT4, WNT16 ), the insulin receptor (INSR), differentiation markers (PRL, IGFBP1, and LEFTY2), and the cyclin-dependent kinase inhibitor p57Kip2 (CDKN1C). Analysis of FOXO1-dependent down-regulated genes uncovered several factors involved in cell cycle regulation, including CCNB1, CCNB2, MCM5, CDC2 and NEK2. Cell viability assay and cell cycle analysis demonstrated that FOXO1 silencing promotes proliferation of differentiating HESCs. Using a glutathione-S-transferase pull-down assay, we confirmed that FOXO1 interacts with progesterone receptor, irrespectively of the presence of ligand. In agreement, knockdown of PR disrupted the regulation of FOXO1 target genes involved in differentiation (IGFBP1, PRL, and WNT4) and cell cycle regulation (CDKN1, CCNB2 and CDC2) in HESCs treated with either cAMP plus medroxyprogesterone acetate or with cAMP alone. Together, the data demonstrate that FOXO1 engages in transcriptional cross talk with progesterone receptor to coordinate cell cycle regulation and differentiation of HESCs.

scholarly journals Inhibition of extracellular signal-regulated kinase 1 by adenovirus mediated small interfering RNA attenuates hepatic fibrosis in rats

Hepatology ◽  
2009 ◽  
Vol 50 (5) ◽  
pp. 1524-1536 ◽  
Author(s):  
Wei Zhong ◽  
Wei-Feng Shen ◽  
Bei-Fang Ning ◽  
Ping-Fang Hu ◽  
Yong Lin ◽  
...  
Keyword(s):  
Hepatic Fibrosis ◽  
Small Interfering Rna ◽  
Extracellular Signal Regulated Kinase ◽  
Extracellular Signal ◽  
Interfering Rna

scholarly journals Menin Missense Mutants Encoded by the MEN1 Gene that Are Targeted to the Proteasome: Restoration of Expression and Activity by CHIP siRNA

2012 ◽  
Vol 97 (2) ◽  
pp. E282-E291 ◽  
Author(s):  
Lucie Canaff ◽  
Jean-François Vanbellinghen ◽  
Ippei Kanazawa ◽  
Hayeon Kwak ◽  
Natasha Garfield ◽  
...  
Keyword(s):  
Small Interfering Rna ◽  
Target Genes ◽  
Kinase Inhibitors ◽  
Proteasome Inhibitors ◽  
Expression Vectors ◽  
Missense Mutations ◽  
Interacting Protein ◽  
Men1 Gene ◽  
Interfering Rna ◽  
Expression And Activity

Context: In multiple endocrine neoplasia type 1 (MEN1) characterized by tumors of parathyroid, enteropancreas, and anterior pituitary, missense mutations in the MEN1 gene product, menin, occur in a subset of cases. The mutant proteins are degraded by the proteasome. However, whether their expression and activity can be restored is not known. Objective: Our objective was to functionally characterize a panel of 16 menin missense mutants, including W423R and S443Y identified in new MEN1 families, with respect to protein stability, targeting to the proteasome and restoration of expression by proteasome inhibitors and expression and function by small interfering RNA technology. Methods: Flag-tagged wild-type (WT) and missense menin mutant expression vectors were transiently transfected in human embryonic kidney (HEK293) and/or rat insulinoma (Rin-5F) cells. Results: The majority of mutants were short-lived, whereas WT menin was stable. Proteasome inhibitors MG132 and PS-341 and inhibition of the chaperone, heat-shock protein 70 (Hsp70), or the ubiquitin ligase, COOH terminus of Hsp70-interacting protein (CHIP), by specific small interfering RNA, restored the levels of the mutants, whereas that of WT menin was largely unaffected. Inhibition of CHIP restored the ability of mutants to mediate normal functions of menin: TGF-β up-regulation of the promoters of its target genes, the cyclin-dependent kinase inhibitors p15 and p21 as well as TGF-β inhibition of cell numbers. Conclusion: When the levels of missense menin mutants that are targeted to the proteasome are normalized they may function similarly to WT menin. Potentially, targeting specific components of the proteasome chaperone pathway could be beneficial in treating a subset of MEN1 cases.

scholarly journals Validation of commercial ERK antibodies against the ERK orthologue of the scleractinian coral Stylophora pistillata

F1000Research ◽  
2017 ◽  
Vol 6 ◽  
pp. 577
Author(s):  
Lucile Courtial ◽  
Vincent Picco ◽  
Gilles Pagès ◽  
Christine Ferrier-Pagès
Keyword(s):  
Cell Fate ◽  
Cell Cycle Regulation ◽  
Signalling Pathway ◽  
Immune Reactivity ◽  
Cell Fate Determination ◽  
Stylophora Pistillata ◽  
Cellular Processes ◽  
Extracellular Signal ◽  
Living Organisms ◽  
Cycle Regulation

The extracellular signal-regulated protein kinase (ERK) signalling pathway controls key cellular processes, such as cell cycle regulation, cell fate determination and the response to external stressors. Although ERK functions are well studied in a variety of living organisms ranging from yeast to mammals, its functions in corals are still poorly known. The present work aims to give practical tools to study the expression level of ERK protein and the activity of the ERK signalling pathway in corals. The antibody characterisation experiment was performed five times and identical results were obtained. The present study validated the immune-reactivity of commercially available antibodies directed against ERK and its phosphorylated/activated forms on protein extracts of the reef-building coral Stylophora pistillata.

scholarly journals Golgi Oncoprotein GOLPH3 Gene Expression Is Regulated by Functional E2F and CREB/ATF Promoter Elements

Genes ◽  
2019 ◽  
Vol 10 (3) ◽  
pp. 247 ◽  
Author(s):  
Beatriz Peñalver-González ◽  
Jon Vallejo-Rodríguez ◽  
Gartze Mentxaka ◽  
Asier Fullaondo ◽  
Ainhoa Iglesias-Ara ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Messenger Rna ◽  
Cell Cycle Regulation ◽  
Luciferase Reporter ◽  
Luciferase Reporter Construct ◽  
Daughter Cells ◽  
Genes Encoding ◽  
E2f Transcription Factors ◽  
Cycle Regulation ◽  
Interfering Rna

The Golgi organelle duplicates its protein and lipid content to segregate evenly between two daughter cells after mitosis. However, how Golgi biogenesis is regulated during interphase remains largely unknown. Here we show that messenger RNA (mRNA) expression of GOLPH3 and GOLGA2, two genes encoding Golgi proteins, is induced specifically in G1 phase, suggesting a link between cell cycle regulation and Golgi growth. We have examined the role of E2F transcription factors, critical regulators of G1 to S progression of the cell cycle, in the expression of Golgi proteins during interphase. We show that promoter activity for GOLPH3, a Golgi protein that is also oncogenic, is induced by E2F1-3 and repressed by E2F7. Mutation of the E2F motifs present in the GOLPH3 promoter region abrogates E2F1-mediated induction of a GOLPH3 luciferase reporter construct. Furthermore, we identify a critical CREB/ATF element in the GOLPH3 promoter that is required for its steady state and ATF2-induced expression. Interestingly, depletion of GOLPH3 with small interfering RNA (siRNA) delays the G1 to S transition in synchronized U2OS cells. Taken together, our results reveal a link between cell cycle regulation and Golgi function, and suggest that E2F-mediated regulation of Golgi genes is required for the timely progression of the cell cycle.

Proinflammatory treatment of astrocytes with lipopolysaccharide results in augmented Ca2+ signaling through increased expression of VIA phospholipase A2 (iPLA2)

2011 ◽  
Vol 300 (3) ◽  
pp. C542-C549 ◽  
Author(s):  
Mikhail Strokin ◽  
Marina Sergeeva ◽  
Georg Reiser
Keyword(s):  
Endoplasmic Reticulum ◽  
Small Interfering Rna ◽  
Signal Transmission ◽  
Brain Inflammation ◽  
Inflammatory Conditions ◽  
Bromoenol Lactone ◽  
Interfering Rna ◽  
The Brain ◽  
Expression And Activity

Many Ca2+-regulated intracellular processes are involved in the development of neuroinflammation. However, the changes of Ca2+ signaling in the brain under inflammatory conditions were hardly studied. ATP-induced Ca2+ signaling is a central event of signal transmission in astrocytic networks. We investigated primary astrocytes after proinflammatory stimulation with lipopolysaccharide (LPS; 100 ng/ml) for 6–24 h. We reveal that Ca2+ responses to purinergic ATP stimulation are significantly increased in amplitude and duration after stimulation with LPS. We detected that increased amplitudes of Ca2+ responses to ATP in LPS-treated astrocytes can be explained by substantial increase of Ca2+ load in stores in endoplasmic reticulum. The mechanism implies enhanced Ca2+ store refilling due to the amplification of capacitative Ca2+ entry. The reason for the increased duration of Ca2+ responses in LPS-treated cells is also the amplified capacitative Ca2+ entry. Next, we established that the molecular mechanism for the LPS-induced amplification of Ca2+ responses in astrocytes is increased expression and activity of VIA phospholipase A2 (VIA iPLA2). Indeed, both gene silencing with specific small interfering RNA and pharmacological inhibition of VIA iPLA2 with S-bromoenol lactone reduced the load of the Ca2+ stores and caused a decrease in the amplitudes of Ca2+ responses in LPS-treated astrocytes to values, which were comparable with those in untreated cells. Our findings highlight a novel regulatory role of VIA iPLA2 in development of inflammation in brain. We suggest that this enzyme might be a possible target for treatment of pathologies related to brain inflammation.

Sign in / Sign up

Export Citation Format

Share Document