scholarly journals Identification of a New Site of Sumoylation on Tel (ETV6) Uncovers a PIAS-Dependent Mode of Regulating Tel Function

2008 ◽  
Vol 28 (7) ◽  
pp. 2342-2357 ◽  
Author(s):  
M. Guy Roukens ◽  
Mariam Alloul-Ramdhani ◽  
Alfred C. O. Vertegaal ◽  
Zeinab Anvarian ◽  
Crina I. A. Balog ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Fate ◽  
Control Of Gene Expression ◽  
Cell Proliferation And Differentiation ◽  
Proliferation And Differentiation ◽  
Spatiotemporal Control ◽  
Identification And Characterization ◽  
In Cells

ABSTRACT Cell proliferation and differentiation are governed by a finely controlled balance between repression and activation of gene expression. The vertebrate Ets transcriptional repressor Tel (ETV6) and its invertebrate orthologue Yan, play pivotal roles in cell fate determination although the precise mechanisms by which repression of gene expression by these factors is achieved are not clearly defined. Here, we report the identification and characterization of the primary site of sumoylation of Tel, lysine 11 (K11), which is highly conserved in vertebrates (except Danio rerio). We demonstrate that in cells PIAS3 binds to Tel and stimulates sumoylation of K11 in the nucleus. Both Tel monomers and oligomers are efficiently sumoylated on K11 in vitro; but in cells only Tel oligomers are found conjugated with SUMO, whereas sumoylation of Tel monomers is transitory and appears to sensitize them for proteasomal degradation. Mechanistically, sumoylation of K11 inhibits repression of gene expression by full-length Tel. In accordance with this observation, we found that sumoylation impedes Tel association with DNA. By contrast, a Tel isoform lacking K11 (TelM43) is strongly repressive. This isoform results from translation from an alternative initiation codon (M43) that is common to all Tel proteins that also contain the K11 sumoylation consensus site. We find that PIAS3 may have a dual, context-dependent influence on Tel; it mediates Tel sumoylation, but it also augments Tel's repressive function in a sumoylation-independent fashion. Our data support a model that suggests that PIAS-mediated sumoylation of K11 and the emergence of TelM43 in early vertebrates are linked and that this serves to refine spatiotemporal control of gene expression by Tel by establishing a pool of Tel molecules that are available either to be recycled to reinforce repression of gene expression or are degraded in a regulated fashion.

scholarly journals Identification and Characterization of a Novel IL-4 Receptor α Chain (IL-4Rα) Antagonist to Inhibit IL-4 Signalling

2015 ◽  
Vol 36 (3) ◽  
pp. 831-842 ◽  
Author(s):  
Nayyar Ahmed ◽  
Pathum Dhanapala ◽  
Cenk Suphioglu
Keyword(s):  
Phage Display ◽  
Synthetic Peptide ◽  
Specific Binding ◽  
Specific Ige ◽  
Psychological Burden ◽  
Cell Proliferation And Differentiation ◽  
Proliferation And Differentiation ◽  
Specific Ige Antibodies

Background/Aims: In recent times, allergy has become a financial, physical and psychological burden to the society as a whole. In allergic cascades, cytokine IL-4 binds to IL-4 receptor (IL-4R), consequently producing allergen-specific IgE antibodies by B cells. In addition, among other functions, IL-4 is also responsible for B and T cell proliferation and differentiation. Hence, characterization of novel antagonists that inhibit IL-4 signalling forms the overall aim of this study. Methods: Phage display was used to screen a random 12-mer synthetic peptide library with a human IL-4Rα to identify peptide candidates. Once identified, the peptides were commercially synthesized and used for in vitro immunoassays. Results: We have successfully used phage display to identify M13 phage clones that demonstrated specific binding to IL-4Rα. The peptide N1 was synthesized for use in ELISA, demonstrating significant binding to IL-4Rα and inhibiting interaction with cytokine IL-4. Furthermore, the peptide was tested in a transfected HEK-Blue IL-4 reporter cell line model, which produces alkaline phosphatase (AP). QUANTI-Blue, a substrate, breaks down in the presence of AP producing a blue coloration. Using this colorimetric analysis, >50% inhibition of IL-4 signalling was achieved. Conclusion: We have successfully identified and characterised a synthetic peptide antagonist against IL-4Rα, which effectively inhibits IL-4 interaction with the IL-4Rα in vitro. Since IL-4 interaction with IL-4Rα is a common pathway for many allergies, a prophylactic treatment can be devised by inhibiting this interaction for future treatment of allergies.

Extracellular matrices and the control of cell proliferation and differentiation in vitro

1983 ◽  
Vol 41 ◽  
pp. 664-667
Author(s):  
D. Gospodarowicz
Keyword(s):  
Cultured Cells ◽  
Cell Attachment ◽  
Control Of Gene Expression ◽  
Serum Factors ◽  
Culture Techniques ◽  
Cell Proliferation And Differentiation ◽  
Proliferation And Differentiation ◽  
Tissue Culture Techniques

Recent investigations suggest that, in vitro, cell-substratum interactions may play other roles in addition to cell anchorage. The extracellular matrix (ECM) that cells can produce and upon which they rest can be held responsible for the final shape the cells will adopt. This shape in turn may play a role in the cell's response to serum factors and its differential response to various growth factors. Components of the ECM produced by cells have also been shown to be involved in cell differentiation and the control of gene expression, as well as in cell attachment. Even soluble matrix components can affect cell shape and the organization of their basal surface and cytoskeleton by stimulating ECM synthesis.One of the major limitations of tissue culture techniques currently in use is that cells rest on plastic. Unless cultured cells can produce their own ECM, the possibility exists that contact with plastic could inhibit them from proliferating or could cause them to lose rapidly their ability to express their correct phenotype. In the present review, we will outline recent studies of the behavior of cells maintained on dishes coated with ECM of known composition. The use of such a substrate for the long-term culture of normal diploid and tumor cells will be described.

scholarly journals Nanotechnology Facilitated Cultured Neuronal Network and Its Applications

2021 ◽  
Vol 22 (11) ◽  
pp. 5552
Author(s):  
Satnam Singh ◽  
Sachin Mishra ◽  
Song Juha ◽  
Manojit Pramanik ◽  
Parasuraman Padmanabhan ◽  
...  
Keyword(s):  
Cell Fate ◽  
Neuronal Network ◽  
Neural Cells ◽  
Cell Proliferation And Differentiation ◽  
Proliferation And Differentiation ◽  
3D Architecture ◽  
Tools And Techniques ◽  
Insight Into

The development of a biomimetic neuronal network from neural cells is a big challenge for researchers. Recent advances in nanotechnology, on the other hand, have enabled unprecedented tools and techniques for guiding and directing neural stem cell proliferation and differentiation in vitro to construct an in vivo-like neuronal network. Nanotechnology allows control over neural stem cells by means of scaffolds that guide neurons to reform synaptic networks in suitable directions in 3D architecture, surface modification/nanopatterning to decide cell fate and stimulate/record signals from neurons to find out the relationships between neuronal circuit connectivity and their pathophysiological functions. Overall, nanotechnology-mediated methods facilitate precise physiochemical controls essential to develop tools appropriate for applications in neuroscience. This review emphasizes the newest applications of nanotechnology for examining central nervous system (CNS) roles and, therefore, provides an insight into how these technologies can be tested in vitro before being used in preclinical and clinical research and their potential role in regenerative medicine and tissue engineering.

scholarly journals Downregulation of Vertebrate Tel (ETV6) and Drosophila Yan Is Facilitated by an Evolutionarily Conserved Mechanism of F-Box-Mediated Ubiquitination

2008 ◽  
Vol 28 (13) ◽  
pp. 4394-4406 ◽  
Author(s):  
M. Guy Roukens ◽  
Mariam Alloul-Ramdhani ◽  
Setareh Moghadasi ◽  
Marjolein Op den Brouw ◽  
David A. Baker
Keyword(s):  
Gene Expression ◽  
Posttranslational Modifications ◽  
Transcriptional Activation ◽  
Proteasomal Degradation ◽  
Control Of Gene Expression ◽  
Evolutionarily Conserved ◽  
Cell Growth And Differentiation ◽  
F Box Protein ◽  
Spatiotemporal Control

ABSTRACT The vertebrate Ets transcriptional repressor Tel (ETV6) and its invertebrate orthologue, Yan, are both indispensable for development, and they orchestrate cell growth and differentiation by binding to DNA, thus inhibiting gene expression. To trigger cell differentiation, these barriers to transcriptional activation must be relieved, and it is established that posttranslational modifications, such as phosphorylation and sumoylation, can specifically impair the repressive functions of Tel and Yan and are crucial for modulating their transcriptional activity. To date, however, relatively little is known about the control of Tel and Yan protein degradation. In recent years, there has been a concentrated effort to assign functions to the large number of F-box proteins encoded by both vertebrate and invertebrate genomes. Here, we report the identification and characterization of a previously unreported, evolutionarily conserved F-box protein named Fbl6. We isolated both human and Drosophila melanogaster fbl6 cDNA and show that the encoded Fbl6 protein binds to both Tel and Yan via their SAM domains. We demonstrate that both Tel and Yan are ubiquitinated, a process which is stimulated by Fbl6 and leads to proteasomal degradation. We recently established that the sumoylation of Tel on lysine 11 negatively regulates its repressive function and that the sumoylation of Tel monomers, but not that of Tel oligomers, may sensitize Tel for proteasomal degradation. Here, we found that Fbl6 regulates Tel/Yan protein stability and allows appropriate spatiotemporal control of gene expression by these repressors.

scholarly journals The Banana Root Endophytome: Differences between Mother Plants and Suckers and Evaluation of Selected Bacteria to Control Fusarium oxysporum f.sp. cubense

2021 ◽  
Vol 7 (3) ◽  
pp. 194
Author(s):  
Carmen Gómez-Lama Cabanás ◽  
Antonio J. Fernández-González ◽  
Martina Cardoni ◽  
Antonio Valverde-Corredor ◽  
Javier López-Cepero ◽  
...  
Keyword(s):  
Fusarium Oxysporum ◽  
Canary Islands ◽  
High Throughput Sequencing ◽  
Fungal Communities ◽  
Phenological Stage ◽  
Mother Plants ◽  
Fusarium Wilt Of Banana ◽  
Identification And Characterization

This study aimed to disentangle the structure, composition, and co-occurrence relationships of the banana (cv. Dwarf Cavendish) root endophytome comparing two phenological plant stages: mother plants and suckers. Moreover, a collection of culturable root endophytes (>1000) was also generated from Canary Islands. In vitro antagonism assays against Fusarium oxysporum f.sp. cubense (Foc) races STR4 and TR4 enabled the identification and characterization of potential biocontrol agents (BCA). Eventually, three of them were selected and evaluated against Fusarium wilt of banana (FWB) together with the well-known BCA Pseudomonas simiae PICF7 under controlled conditions. Culturable and non-culturable (high-throughput sequencing) approaches provided concordant information and showed low microbial diversity within the banana root endosphere. Pseudomonas appeared as the dominant genus and seemed to play an important role in the banana root endophytic microbiome according to co-occurrence networks. Fungal communities were dominated by the genera Ophioceras, Cyphellophora, Plecosphaerella, and Fusarium. Overall, significant differences were found between mother plants and suckers, suggesting that the phenological stage determines the recruitment and organization of the endophytic microbiome. While selected native banana endophytes showed clear antagonism against Foc strains, their biocontrol performance against FWB did not improve the outcome observed for a non-indigenous reference BCA (strain PICF7).

scholarly journals Computational design and experimental characterization of a photo-controlled mRNA-cap guanine-N7 methyltransferase

2021 ◽  
Author(s):  
Dennis Reichert ◽  
Helena Schepers ◽  
Julian Simke ◽  
Horst Lechner ◽  
Wolfgang Dörner ◽  
...  
Keyword(s):  
Gene Expression ◽  
Computational Design ◽  
Eukaryotic Cells ◽  
Transcriptional Level ◽  
Experimental Characterization ◽  
Temporal Control ◽  
Control Of Gene Expression ◽  
Multicellular Organisms

The spatial and temporal control of gene expression at the post-transcriptional level is essential in eukaryotic cells and developing multicellular organisms. In recent years optochemical and optogenetic tools have enabled...

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