scholarly journals Complex formation with the fibroin gene enhancer through a protein-protein interaction analyzed by a modified DNA-binding assay

1989 ◽  
Vol 264 (8) ◽  
pp. 4599-4604
Author(s):  
K Matsuno ◽  
T Suzuki ◽  
S Takiya ◽  
Y Suzuki
Keyword(s):  
Dna Binding ◽  
Complex Formation ◽  
Protein Interaction ◽  
Binding Assay ◽  
Protein Protein Interaction ◽  
Modified Dna ◽  
Fibroin Gene ◽  
Gene Enhancer ◽  
Dna Binding Assay

scholarly journals Targeting NF-κB Signaling by Calebin A, a Compound of Turmeric, in Multicellular Tumor Microenvironment: Potential Role of Apoptosis Induction in CRC Cells

Biomedicines ◽  
2020 ◽  
Vol 8 (8) ◽  
pp. 236 ◽  
Author(s):  
Constanze Buhrmann ◽  
Parviz Shayan ◽  
Kishore Banik ◽  
Ajaikumar B. Kunnumakkara ◽  
Peter Kubatka ◽  
...  
Keyword(s):  
Tumor Microenvironment ◽  
Dna Binding ◽  
Binding Assay ◽  
Nuclear Translocation ◽  
Hct116 Cell ◽  
Direct Interaction ◽  
Dependent Manner ◽  
Natural Agents ◽  
Iκb Kinase ◽  
Dna Binding Assay

Increasing lines of evidence suggest that chronic inflammation mediates most chronic diseases, including cancer. The transcription factor, NF-κB, has been shown to be a major regulator of inflammation and metastasis in tumor cells. Therefore, compounds or any natural agents that can inhibit NF-κB activation have the potential to prevent and treat cancer. However, the mechanism by which Calebin A, a component of turmeric, regulates inflammation and disrupts the interaction between HCT116 colorectal cancer (CRC) cells and multicellular tumor microenvironment (TME) is still poorly understood. The 3D-alginate HCT116 cell cultures in TME were treated with Calebin A, BMS-345541, and dithiothreitol (DTT) and examined for invasiveness, proliferation, and apoptosis. The mechanism of TME-induced malignancy of cancer cells was confirmed by phase contrast, Western blotting, immunofluorescence, and DNA-binding assay. We found through DNA binding assay, that Calebin A inhibited TME-induced NF-κB activation in a dose-dependent manner. As a result of this inhibition, NF-κB phosphorylation and NF-κB nuclear translocation were down-modulated. Calebin A, or IκB-kinase (IKK) inhibitor (BMS-345541) significantly inhibited the direct interaction of nuclear p65 to DNA, and interestingly this interaction was reversed by DTT. Calebin A also suppressed the expression of NF-κB-promoted anti-apoptotic (Bcl-2, Bcl-xL, survivin), proliferation (Cyclin D1), invasion (MMP-9), metastasis (CXCR4), and down-regulated apoptosis (Caspase-3) gene biomarkers, leading to apoptosis in HCT116 cells. These results suggest that Calebin A can suppress multicellular TME-promoted CRC cell invasion and malignancy by inhibiting the NF-κB-promoting inflammatory pathway associated with carcinogenesis, underlining the potential of Calebin A for CRC treatment.

Establishment of a robust dengue virus NS3–NS5 binding assay for identification of protein–protein interaction inhibitors

2012 ◽  
Vol 96 (3) ◽  
pp. 305-314 ◽  
Author(s):  
Hirotaka Takahashi ◽  
Chikako Takahashi ◽  
Nicole J. Moreland ◽  
Young-Tae Chang ◽  
Tatsuya Sawasaki ◽  
...  
Keyword(s):  
Dengue Virus ◽  
Protein Interaction ◽  
Binding Assay ◽  
Protein Protein Interaction

scholarly journals GT198 Is a Target of Oncology Drugs and Anticancer Herbs

2021 ◽  
Vol 2 ◽  
Author(s):  
Junfeng Pang ◽  
Jie Gao ◽  
Liyong Zhang ◽  
Nahid F. Mivechi ◽  
Lan Ko
Keyword(s):  
Dna Binding ◽  
Natural Product ◽  
Tumor Angiogenesis ◽  
Drug Target ◽  
Binding Assay ◽  
Organic Chemical ◽  
High Efficacy ◽  
Compound Identification ◽  
Dna Binding Assay

Tumor angiogenesis is a hallmark of cancer. Therapeutic drug inhibitors targeting angiogenesis are clinically effective. We have previously identified GT198 (gene symbol PSMC3IP, also known as Hop2) as an oncoprotein that induces tumor angiogenesis in human cancers, including oral cancer. In this study, we show that the GT198 protein is a direct drug target of more than a dozen oncology drugs and several clinically successful anticancer herbs. GT198 is a DNA repair protein that binds to DNA. Using an in vitro DNA-binding assay, we tested the approved oncology drug set VII from the National Cancer Institute containing 129 oncology drugs. Identified GT198 inhibitors include but are not limited to mitoxantrone, doxorubicin, paclitaxel, etoposide, dactinomycin, and imatinib. Paclitaxel and etoposide have higher binding affinities, whereas doxorubicin has higher binding efficacy due to competitive inhibition. GT198 shares protein sequence homology with DNA topoisomerases, which are known drug targets, so that GT198 is likely a new drug target previously unrecognized. To seek more powerful GT198 inhibitors, we further tested several anticancer herbal extracts. The positive anticancer herbs with high affinity and high efficacy are all clinically successful ones, including allspice from Jamaica, Gleditsia sinensis or honey locust from China, and BIRM from Ecuador. Partial purification of allspice using an organic chemical approach demonstrated great feasibility of natural product purification, when the activity is monitored by the in vitro DNA-binding assay using GT198 as a target. Together, our study reveals GT198 as a new targeting mechanism for existing oncology drugs. The study also delivers an excellent drug target suitable for compound identification and natural product purification. In particular, this study opens an opportunity to rapidly identify drugs with high efficacy and low toxicity from nature.

Functional interference between the ubiquitous and constitutive octamer transcription factor 1 (OTF-1) and the glucocorticoid receptor by direct protein-protein interaction involving the homeo subdomain of OTF-1

1992 ◽  
Vol 12 (11) ◽  
pp. 4960-4969
Author(s):  
E Kutoh ◽  
P E Strömstedt ◽  
L Poellinger
Keyword(s):  
Transcription Factor ◽  
Dna Binding ◽  
Glucocorticoid Receptor ◽  
Protein Interaction ◽  
Binding Activity ◽  
Dependent Manner ◽  
Protein Protein Interaction ◽  
Dna Binding Activity ◽  
Functional Interference

The ubiquitous and constitutive octamer transcription factor OTF-1 (Oct 1) is the target of positive regulation by the potent herpes simplex virus trans-activator VP16, which forms a complex with the homeodomain of OTF-1. Here we present evidence that the glucocorticoid receptor can negatively regulate OTF-1 function by a mechanism that is independent of DNA binding. In vivo-expressed glucocorticoid receptor inhibited in a hormone-dependent manner activation of a minimal promoter construct carrying a functional octamer site. Moreover, expression of the receptor in vivo resulted in hormone-dependent repression of OTF-1-dependent DNA-binding activity in nuclear extract. In vitro, the DNA-binding activity of partially purified OTF-1 was repressed following incubation with purified glucocorticoid receptor. Cross-linking and immunoprecipitation experiments indicated that the functional interference may be due to a strong association between these two proteins in solution. Finally, preliminary evidence indicates that the homeo subdomain of OTF-1 that directs formation of a complex with VP16 may also be critical for interaction with the glucocorticoid receptor. Thus, OTF-1 is a target for both positive and negative regulation by protein-protein interaction. Moreover, the functional interference between OTF-1 and the glucocorticoid receptor represents a novel regulatory mechanism in the cross-coupling of signal transduction pathways of nuclear receptors and constitutive transcription factors.

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