scholarly journals Alteration of RNA Splicing by Small-Molecule Inhibitors of the Interaction between NHP2L1 and U4

2017 ◽  
Vol 23 (2) ◽  
pp. 164-173 ◽  
Author(s):  
Barthelemy Diouf ◽  
Wenwei Lin ◽  
Asli Goktug ◽  
Christy R. R. Grace ◽  
Michael Brett Waddell ◽  
...  

Splicing is an important eukaryotic mechanism for expanding the transcriptome and proteome, influencing a number of biological processes. Understanding its regulation and identifying small molecules that modulate this process remain a challenge. We developed an assay based on time-resolved fluorescence resonance energy transfer (TR-FRET) to detect the interaction between the protein NHP2L1 and U4 RNA, which are two key components of the spliceosome. We used this assay to identify small molecules that interfere with this interaction in a high-throughput screening (HTS) campaign. Topotecan and other camptothecin derivatives were among the top hits. We confirmed that topotecan disrupts the interaction between NHP2L1 and U4 by binding to U4 and inhibits RNA splicing. Our data reveal new functions of known drugs that could facilitate the development of therapeutic strategies to modify splicing and alter gene function.

2007 ◽  
Vol 13 (1) ◽  
pp. 17-28 ◽  
Author(s):  
Thomas Schröter ◽  
Dmitriy Minond ◽  
Amiee Weiser ◽  
Chinh Dao ◽  
Jeff Habel ◽  
...  

Kinases are important drug discovery targets for a wide variety of therapeutic indications; consequently, the measurement of kinase activity remains a common high-throughput screening (HTS) application. Recently, enzyme-coupled luciferase-kinase (LK) format assays have been introduced. This format measures luminescence resulting from metabolism of adenosine triphosphate (ATP) via a luciferin/luciferase-coupled reaction. In the research presented here, 1536-well format time-resolved fluorescence resonance energy transfer (TR-FRET) and LK assays were created to identify novel Rho-associated kinase II (ROCK-II) inhibitors. HTS campaigns for both assays were conducted in this miniaturized format. It was found that both assays were able to consistently reproduce the expected pharmacology of inhibitors known to be specific to ROCK-II (fasudil IC50: 283 ± 27 nM and 336 ± 54 nM for TR-FRET and LK assays, respectively; Y-27632 IC50: 133 ± 7.8 nM and 150 ± 22 nM for TR-FRET and LK assays, respectively). In addition, both assays proved robust for HTS efforts, demonstrating excellent plate Z′ values during the HTS campaign (0.84 ± 0.03; 0.72 ± 0.05 for LK and TR-FRET campaigns, respectively). Both formats identified scaffolds of known and novel ROCK-II inhibitors with similar sensitivity. A comparison of the performance of these 2 assay formats in an HTS campaign was enabled by the existence of a subset of 25,000 compounds found in both our institutional and the Molecular Library Screening Center Network screening files. Analysis of the HTS campaign results based on this subset of common compounds showed that both formats had comparable total hit rates, hit distributions, amount of hit clusters, and format-specific artifact. It can be concluded that both assay formats are suitable for the discovery of ROCK-II inhibitors, and the choice of assay format depends on reagents and/or screening technology available. ( Journal of Biomolecular Screening 2008:17-28)


2003 ◽  
Vol 8 (4) ◽  
pp. 381-392 ◽  
Author(s):  
Xiang Wu ◽  
J. Fraser Glickman ◽  
Benjamin R. Bowen ◽  
Matthew A. Sills

Many assay technologies currently exist to develop high-throughput screening assays, and the number of choices continues to increase. Results from a previous study comparing assay technologies in our laboratory do not support the common assumption that the same hits would be found regardless of which assay technology is used. To extend this investigation, a nuclear receptor antagonist assay was developed using 3 assay formats: AlphaScreen, time-resolved fluorescence (TRF), and time-resolved fluorescence resonance energy transfer (TR-FRET). Compounds (∼42,000) from the Novartis library were evaluated in all 3 assay formats. A total of 128 compounds were evaluated in dose-response experiments, and 109 compounds were confirmed active from all 3 formats. The AlphaScreen, TRF, and TR-FRET assay technologies identified 104, 23, and 57 active compounds, respectively, with only 18 compounds active in all 3 assay formats. A total of 128 compounds were evaluated in a cell-based functional assay, and 35 compounds demonstrated activity in this cellular assay. Furthermore, 34, 11, and 16 hits that were originally identified in the dose-response experiment by AlphaScreen, TRF, and TR-FRET assay technologies, respectively, were functionally active. The results of the study indicated that AlphaScreen identified the greatest number of functional antagonists.


2009 ◽  
Vol 14 (10) ◽  
pp. 1263-1268 ◽  
Author(s):  
Nunzianna Doti ◽  
Daniela Marasco ◽  
Carlo Pedone ◽  
Marco Sabatella ◽  
Menotti Ruvo

Using a commercially available time-resolved fluorescence resonance energy transfer (TR-FRET)—based assay for IKKβ, the authors have automated the assay procedure on a high-throughput screening station to carry out screening campaigns on multiwell plates. They have determined the Z′ factor and optimized volumes, times, and time-resolved fluorescence parameters. They have also compared 2 kinases with different fusion tags, the influence of different enzyme/substrate ratios and of DMSO presence at different concentration. The authors found that glutathione S-transferase (GST)—fused IKKβ shows better signal-to-noise (S/N) ratios over the poly-histidine-tagged variant. The substrate can be used at 50 nM with optimal performances when the enzyme is used at 2 nM. DMSO at 0.2% and 1% only slightly affects the S/N ratio, whereas when used at 2%, the final concentration deriving from a 50-fold dilution from a 5-mM stock solution in pure solvent, S/N undergoes a decrease of about 15%. Under the optimized conditions, the assay Z′ factor calculated over 192 data points has an optimized value of 0.881 and allows the testing of 94 molecules in quadruplicate in 140 min.


Biochemistry ◽  
2005 ◽  
Vol 44 (11) ◽  
pp. 4312-4321 ◽  
Author(s):  
Olivier Dalmas ◽  
Marie-Ange Do Cao ◽  
Miguel R. Lugo ◽  
Frances J. Sharom ◽  
Attilio Di Pietro ◽  
...  

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