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  1. Article ; Online: Study of PEG-

    Ashkenazi, Shaked / Matsanov, Pnina / Nassar-Marjiya, Eid / Farah, Shady / Weitz, Iris S

    ACS omega

    2024  Volume 9, Issue 11, Page(s) 13382–13390

    Abstract: A nanocapsule shell of poly(ethylene glycol)- ...

    Abstract A nanocapsule shell of poly(ethylene glycol)-
    Language English
    Publishing date 2024-03-05
    Publishing country United States
    Document type Journal Article
    ISSN 2470-1343
    ISSN (online) 2470-1343
    DOI 10.1021/acsomega.3c10447
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article: Effective cell-free drug screening protocol for protein-protein interaction

    Ashkenazi, Shaked / Alexander Plotnikov / Anat Bahat / Rivka Dikstein

    Analytical biochemistry. 2017 Sept. 01, v. 532

    2017  

    Abstract: Specific protein-protein interaction (PPI) is an essential feature of many cellular processes however, targeting these interactions by small molecules is highly challenging due to the nature of the interaction interface. Thus, screening for PPI ... ...

    Abstract Specific protein-protein interaction (PPI) is an essential feature of many cellular processes however, targeting these interactions by small molecules is highly challenging due to the nature of the interaction interface. Thus, screening for PPI inhibitors requires enormous number of compounds. Here we describe a simple and improved protocol designed for a search of direct PPI inhibitors. We engineered a bacterial expression system for the split-Renilla luciferase (RL) complementation assay that monitors PPI. This enables production of large quantities of the RL fusion proteins in a simple and cost effective manner that is suitable for very large screens. Subsequently, inhibitory compounds are analyzed in a similar complementation assay in living cultured mammalian cells to select for those that can penetrate cells. We applied this method to NF-κB, a family of dimeric transcription factors that plays central roles in immune responses, cell survival and aging, and its dysregulation is linked to many pathological states. This strategy led to the identification of several direct NF-κB inhibitors. As the described protocol is very straightforward and robust it may be suitable for many pairs of interacting proteins.
    Keywords cell viability ; chemical elements ; cost effectiveness ; drugs ; immune response ; luciferase ; mammals ; pathological processes and conditions ; protein-protein interactions ; screening ; transcription (genetics) ; transcription factor NF-kappa B
    Language English
    Dates of publication 2017-0901
    Size p. 53-59.
    Publishing place Elsevier Inc.
    Document type Article
    ZDB-ID 1110-1
    ISSN 1096-0309 ; 0003-2697
    ISSN (online) 1096-0309
    ISSN 0003-2697
    DOI 10.1016/j.ab.2017.05.030
    Database NAL-Catalogue (AGRICOLA)

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  3. Article ; Online: Effective cell-free drug screening protocol for protein-protein interaction.

    Ashkenazi, Shaked / Plotnikov, Alexander / Bahat, Anat / Dikstein, Rivka

    Analytical biochemistry

    2017  Volume 532, Page(s) 53–59

    Abstract: Specific protein-protein interaction (PPI) is an essential feature of many cellular processes however, targeting these interactions by small molecules is highly challenging due to the nature of the interaction interface. Thus, screening for PPI ... ...

    Abstract Specific protein-protein interaction (PPI) is an essential feature of many cellular processes however, targeting these interactions by small molecules is highly challenging due to the nature of the interaction interface. Thus, screening for PPI inhibitors requires enormous number of compounds. Here we describe a simple and improved protocol designed for a search of direct PPI inhibitors. We engineered a bacterial expression system for the split-Renilla luciferase (RL) complementation assay that monitors PPI. This enables production of large quantities of the RL fusion proteins in a simple and cost effective manner that is suitable for very large screens. Subsequently, inhibitory compounds are analyzed in a similar complementation assay in living cultured mammalian cells to select for those that can penetrate cells. We applied this method to NF-κB, a family of dimeric transcription factors that plays central roles in immune responses, cell survival and aging, and its dysregulation is linked to many pathological states. This strategy led to the identification of several direct NF-κB inhibitors. As the described protocol is very straightforward and robust it may be suitable for many pairs of interacting proteins.
    MeSH term(s) Drug Evaluation, Preclinical ; High-Throughput Screening Assays/methods ; Humans ; Luciferases, Renilla/metabolism ; Luminescent Measurements ; NF-kappa B/metabolism ; Protein Binding ; Protein Interaction Mapping/methods ; Protein Interaction Maps/drug effects ; Small Molecule Libraries/pharmacology
    Chemical Substances NF-kappa B ; Small Molecule Libraries ; Luciferases, Renilla (EC 1.13.12.5)
    Language English
    Publishing date 2017-09-01
    Publishing country United States
    Document type Journal Article
    ZDB-ID 1110-1
    ISSN 1096-0309 ; 0003-2697
    ISSN (online) 1096-0309
    ISSN 0003-2697
    DOI 10.1016/j.ab.2017.05.030
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article ; Online: Cancer-Associated Eukaryotic Translation Initiation Factor 1A Mutants Impair Rps3 and Rps10 Binding and Enhance Scanning of Cell Cycle Genes [Erratum: Mar. 2019, 39(6), p. e00049-19]

    Sehrawat, Urmila / Koning, Femke / Ashkenazi, Shaked / Stelzer, Gil / Leshkowitz, Dena / Dikstein, Rivka

    Molecular and Cellular Biology. 2019 Feb. 1, v. 39, no. 3, p. e00441-18

    2019  

    Abstract: Protein synthesis is linked to cell proliferation, and its deregulation contributes to cancer. Eukaryotic translation initiation factor 1A (eIF1A) plays a key role in scanning and AUG selection and differentially affects the translation of distinct mRNAs. ...

    Abstract Protein synthesis is linked to cell proliferation, and its deregulation contributes to cancer. Eukaryotic translation initiation factor 1A (eIF1A) plays a key role in scanning and AUG selection and differentially affects the translation of distinct mRNAs. Its unstructured N-terminal tail (NTT) is frequently mutated in several malignancies. Here we report that eIF1A is essential for cell proliferation and cell cycle progression. Ribosome profiling of eIF1A knockdown cells revealed a substantial enrichment of cell cycle mRNAs among the downregulated genes, which are predominantly characterized by a lengthy 5′ untranslated region (UTR). Conversely, eIF1A depletion caused a broad stimulation of 5′ UTR initiation at a near cognate AUG, unveiling a prominent role of eIF1A in suppressing 5′ UTR translation. In addition, the AUG context-dependent autoregulation of eIF1 was disrupted by eIF1A depletion, suggesting their cooperation in AUG context discrimination and scanning. Importantly, cancer-associated eIF1A NTT mutants augmented the eIF1A positive effect on a long 5′ UTR, while they hardly affected AUG selection. Mechanistically, these mutations diminished the eIF1A interaction with Rps3 and Rps10 implicated in scanning arrest. Our findings suggest that the reduced binding of eIF1A NTT mutants to the ribosome retains its open state and facilitates scanning of long 5′ UTR-containing cell cycle genes.
    Keywords autoregulation ; cell cycle ; cell proliferation ; protein synthesis ; ribosomes ; 5′ UTR ; Rps10 ; Rps3 ; translation initiation ; eIF1 ; eIF1A ; eIF1AX
    Language English
    Dates of publication 2019-0201
    Size p. e00441-18
    Publishing place Taylor & Francis
    Document type Article ; Online
    ZDB-ID 779397-2
    ISSN 1098-5549 ; 0270-7306
    ISSN (online) 1098-5549
    ISSN 0270-7306
    DOI 10.1128/MCB.00441-18
    Database NAL-Catalogue (AGRICOLA)

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  5. Article ; Online: Erratum for Sehrawat et al., "Cancer-Associated Eukaryotic Translation Initiation Factor 1A Mutants Impair Rps3 and Rps10 Binding and Enhance Scanning of Cell Cycle Genes".

    Sehrawat, Urmila / Koning, Femke / Ashkenazi, Shaked / Stelzer, Gil / Leshkowitz, Dena / Dikstein, Rivka

    Molecular and cellular biology

    2019  Volume 39, Issue 6

    Language English
    Publishing date 2019-03-01
    Publishing country United States
    Document type Journal Article ; Published Erratum
    ZDB-ID 779397-2
    ISSN 1098-5549 ; 0270-7306
    ISSN (online) 1098-5549
    ISSN 0270-7306
    DOI 10.1128/MCB.00049-19
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article ; Online: Cancer-Associated Eukaryotic Translation Initiation Factor 1A Mutants Impair Rps3 and Rps10 Binding and Enhance Scanning of Cell Cycle Genes.

    Sehrawat, Urmila / Koning, Femke / Ashkenazi, Shaked / Stelzer, Gil / Leshkowitz, Dena / Dikstein, Rivka

    Molecular and cellular biology

    2019  Volume 39, Issue 3

    Abstract: Protein synthesis is linked to cell proliferation, and its deregulation contributes to cancer. Eukaryotic translation initiation factor 1A (eIF1A) plays a key role in scanning and AUG selection and differentially affects the translation of distinct mRNAs. ...

    Abstract Protein synthesis is linked to cell proliferation, and its deregulation contributes to cancer. Eukaryotic translation initiation factor 1A (eIF1A) plays a key role in scanning and AUG selection and differentially affects the translation of distinct mRNAs. Its unstructured N-terminal tail (NTT) is frequently mutated in several malignancies. Here we report that eIF1A is essential for cell proliferation and cell cycle progression. Ribosome profiling of eIF1A knockdown cells revealed a substantial enrichment of cell cycle mRNAs among the downregulated genes, which are predominantly characterized by a lengthy 5' untranslated region (UTR). Conversely, eIF1A depletion caused a broad stimulation of 5' UTR initiation at a near cognate AUG, unveiling a prominent role of eIF1A in suppressing 5' UTR translation. In addition, the AUG context-dependent autoregulation of eIF1 was disrupted by eIF1A depletion, suggesting their cooperation in AUG context discrimination and scanning. Importantly, cancer-associated eIF1A NTT mutants augmented the eIF1A positive effect on a long 5' UTR, while they hardly affected AUG selection. Mechanistically, these mutations diminished the eIF1A interaction with Rps3 and Rps10 implicated in scanning arrest. Our findings suggest that the reduced binding of eIF1A NTT mutants to the ribosome retains its open state and facilitates scanning of long 5' UTR-containing cell cycle genes.
    MeSH term(s) 5' Untranslated Regions ; Animals ; Cell Cycle Checkpoints/physiology ; Cell Proliferation/physiology ; Codon, Initiator ; Eukaryotic Initiation Factor-1/genetics ; Eukaryotic Initiation Factor-1/metabolism ; Fibroblasts ; HEK293 Cells ; Humans ; Mice ; Mouse Embryonic Stem Cells ; Mutation ; Neoplasms/genetics ; Protein Binding ; Protein Biosynthesis ; RNA, Messenger/genetics ; RNA, Messenger/metabolism ; Ribosomal Proteins/genetics ; Ribosomal Proteins/metabolism ; Ribosomes/metabolism
    Chemical Substances 5' Untranslated Regions ; Codon, Initiator ; Eukaryotic Initiation Factor-1 ; RNA, Messenger ; RPS10 protein, human ; RPS3 protein, human ; Ribosomal Proteins ; eukaryotic peptide initiation factor-1A
    Language English
    Publishing date 2019-01-16
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 779397-2
    ISSN 1098-5549 ; 0270-7306
    ISSN (online) 1098-5549
    ISSN 0270-7306
    DOI 10.1128/MCB.00441-18
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  7. Article ; Online: Inhibitors of eIF4G1-eIF1 uncover its regulatory role of ER/UPR stress-response genes independent of eIF2α-phosphorylation.

    Sehrawat, Urmila / Haimov, Ora / Weiss, Benjamin / Tamarkin-Ben Harush, Ana / Ashkenazi, Shaked / Plotnikov, Alexander / Noiman, Tzahi / Leshkowitz, Dena / Stelzer, Gil / Dikstein, Rivka

    Proceedings of the National Academy of Sciences of the United States of America

    2022  Volume 119, Issue 30, Page(s) e2120339119

    Abstract: During translation initiation, eIF4G1 dynamically interacts with eIF4E and eIF1. While the role of eIF4E-eIF4G1 is well established, the regulatory functions of eIF4G1-eIF1 are poorly understood. Here, we report the identification of the eIF4G1-eIF1 ... ...

    Abstract During translation initiation, eIF4G1 dynamically interacts with eIF4E and eIF1. While the role of eIF4E-eIF4G1 is well established, the regulatory functions of eIF4G1-eIF1 are poorly understood. Here, we report the identification of the eIF4G1-eIF1 inhibitors i14G1-10 and i14G1-12. i14G1s directly bind eIF4G1 and inhibit translation in vitro and in the cell, and their effects on translation are dependent on eIF4G1 levels. Translatome analyses revealed that i14G1s mimic eIF1 and eIF4G1 perturbations on the stringency of start codon selection and the opposing roles of eIF1-eIF4G1 in scanning-dependent and scanning-independent short 5' untranslated region (UTR) translation. Remarkably, i14G1s activate ER/unfolded protein response (UPR) stress-response genes via enhanced ribosome loading, elevated 5'UTR translation at near-cognate AUGs, and unexpected concomitant up-regulation of coding-region translation. These effects are, at least in part, independent of eIF2α-phosphorylation. Interestingly, eIF4G1-eIF1 interaction itself is negatively regulated by ER stress and mTOR inhibition. Thus, i14G1s uncover an unknown mechanism of ER/UPR translational stress response and are valuable research tools and potential drugs against diseases exhibiting dysregulated translation.
    MeSH term(s) Animals ; Codon, Initiator ; Endoplasmic Reticulum Stress/genetics ; Eukaryotic Initiation Factor-2/metabolism ; Eukaryotic Initiation Factor-4G/antagonists & inhibitors ; Eukaryotic Initiation Factor-4G/metabolism ; Eukaryotic Initiation Factors/antagonists & inhibitors ; Eukaryotic Initiation Factors/metabolism ; Humans ; Mice ; Neoplasm Proteins/antagonists & inhibitors ; Neoplasm Proteins/metabolism ; Nerve Tissue Proteins/antagonists & inhibitors ; Nerve Tissue Proteins/metabolism ; Phosphorylation ; Protein Biosynthesis ; Unfolded Protein Response/genetics
    Chemical Substances Codon, Initiator ; EIF1 protein, human ; EIF2S1 protein, human ; EIF4G1 protein, human ; Eukaryotic Initiation Factor-2 ; Eukaryotic Initiation Factor-4G ; Eukaryotic Initiation Factors ; Neoplasm Proteins ; Nerve Tissue Proteins
    Language English
    Publishing date 2022-07-20
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 209104-5
    ISSN 1091-6490 ; 0027-8424
    ISSN (online) 1091-6490
    ISSN 0027-8424
    DOI 10.1073/pnas.2120339119
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  8. Article ; Online: COVID-19 Compromises In The Medical Practice And The Consequential Effect On Endometriosis Patients

    Ashkenazi, Shaked / Huseby, Ole Linvaag / Kroken, Gard / Soto, Luis Adrian / Pents, Marius / Tran, Grace / Lewandowska, Roksanna / Lo Schivo, Alessandra / kwiatkowski, Sebastian

    medRxiv

    Abstract: Background and purpose In response to the ongoing coronavirus disease 2019 (COVID-19) pandemic, self-isolation practices aimed to curb the spread of COVID-19 have severely complicated the medical management of patients suffering from endometriosis and ... ...

    Abstract Background and purpose In response to the ongoing coronavirus disease 2019 (COVID-19) pandemic, self-isolation practices aimed to curb the spread of COVID-19 have severely complicated the medical management of patients suffering from endometriosis and their physical and mental well- being. Endometriosis, the main cause for chronic pelvic pain (CPP), is a highly prevalent disease characterized by the presence of endometrial tissue in locations outside the uterine cavity that affects up to 10% of women in their reproductive age. This study aimed to explore the effects of the global COVID-19 pandemic on patients suffering from endometriosis across multiple countries, and to investigate the different approaches to the medical management of these patients based on their self- reported experiences. Methods A cross-sectional survey, partially based on validated quality of life questionnaires for endometriosis patients, was initially created in English, which was then reviewed by experts. Through the process of assessing face and content validity, the questionnaire was then translated to fifteen different languages following the WHO recommendations for medical translation. After evaluation, the questionnaire was converted into a web form and distributed across different platforms. An analysis of 2964 responses of participants from 59 countries suffering from self-reported endometriosis was then conducted. Results The data shows an association between COVID-19 imposed compromises with the reported worsening of the mental state of the participants, as well as with the aggravation of their symptoms. For the 1174 participants who had their medical appointments cancelled, 43.7% (n=513) reported that their symptoms had been aggravated, and 49.3% (n=579) reported that their mental state had worsened. In comparison, of the 1180 participants who kept their appointments, only 29.4% (n=347) stated that their symptoms had been aggravated, and 27.5% (n=325) stated their mental health had worsened. 610 participants did not have medical appointments scheduled, and these participants follow a similar pattern as the participants who kept their appointments, with 29.0% (n=177) reporting aggravation of symptoms and 28.2% (n=172) reporting that their mental state had worsened. Conclusions These findings suggest that COVID-19 pandemic has had a clinically significant negative effect on the mental and physical well-being of participants suffering from endometriosis based on their self-reported experiences. Thus, they show the importance of further assessment and reevaluation of the current and future management of this condition in medical practices worldwide. Keywords Endometriosis, COVID-19, questionnaire, Quality of life, Mental health, Physical health
    Keywords covid19
    Language English
    Publishing date 2021-05-10
    Publisher Cold Spring Harbor Laboratory Press
    Document type Article ; Online
    DOI 10.1101/2021.05.04.21255000
    Database COVID19

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  9. Article ; Online: A Novel Allosteric Mechanism of NF-κB Dimerization and DNA Binding Targeted by an Anti-Inflammatory Drug

    Ashkenazi, Shaked / Plotnikov, Alexander / Bahat, Anat / Ben-Zeev, Efrat / Warszawski, Shira / Dikstein, Rivka

    Molecular and Cellular Biology. 2016 Apr. 1, v. 36, no. 8 p.1237-1247

    2016  

    Abstract: The NF-κB family plays key roles in immune and stress responses, and its deregulation contributes to several diseases. Therefore its modulation has become an important therapeutic target. Here, we used a high-throughput screen for small molecules that ... ...

    Abstract The NF-κB family plays key roles in immune and stress responses, and its deregulation contributes to several diseases. Therefore its modulation has become an important therapeutic target. Here, we used a high-throughput screen for small molecules that directly inhibit dimerization of the NF-κB protein p65. One of the identified inhibitors is withaferin A (WFA), a documented anticancer and anti-inflammatory compound. Computational modeling suggests that WFA contacts the dimerization interface on one subunit and surface residues E285 and Q287 on the other. Despite their locations far from the dimerization site, E285 and Q287 substitutions diminished both dimerization and the WFA effect. Further investigation revealed that their effects on dimerization are associated with their proximity to a conserved hydrophobic core domain (HCD) that is crucial for dimerization and DNA binding. Our findings established NF-κB dimerization as a drug target and uncovered an allosteric domain as a target of WFA action.
    Keywords DNA ; anti-inflammatory agents ; cell biology ; dimerization ; hydrophobicity ; therapeutics
    Language English
    Dates of publication 2016-0401
    Size p. 1237-1247.
    Publishing place Taylor & Francis
    Document type Article ; Online
    ZDB-ID 779397-2
    ISSN 1098-5549 ; 0270-7306
    ISSN (online) 1098-5549
    ISSN 0270-7306
    DOI 10.1128/MCB.00895-15
    Database NAL-Catalogue (AGRICOLA)

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  10. Article ; Online: A Novel Allosteric Mechanism of NF-κB Dimerization and DNA Binding Targeted by an Anti-Inflammatory Drug.

    Ashkenazi, Shaked / Plotnikov, Alexander / Bahat, Anat / Ben-Zeev, Efrat / Warszawski, Shira / Dikstein, Rivka

    Molecular and cellular biology

    2016  Volume 36, Issue 8, Page(s) 1237–1247

    Abstract: The NF-κB family plays key roles in immune and stress responses, and its deregulation contributes to several diseases. Therefore its modulation has become an important therapeutic target. Here, we used a high-throughput screen for small molecules that ... ...

    Abstract The NF-κB family plays key roles in immune and stress responses, and its deregulation contributes to several diseases. Therefore its modulation has become an important therapeutic target. Here, we used a high-throughput screen for small molecules that directly inhibit dimerization of the NF-κB protein p65. One of the identified inhibitors is withaferin A (WFA), a documented anticancer and anti-inflammatory compound. Computational modeling suggests that WFA contacts the dimerization interface on one subunit and surface residues E285 and Q287 on the other. Despite their locations far from the dimerization site, E285 and Q287 substitutions diminished both dimerization and the WFA effect. Further investigation revealed that their effects on dimerization are associated with their proximity to a conserved hydrophobic core domain (HCD) that is crucial for dimerization and DNA binding. Our findings established NF-κB dimerization as a drug target and uncovered an allosteric domain as a target of WFA action.
    MeSH term(s) Allosteric Regulation/drug effects ; Amino Acid Sequence ; Anti-Inflammatory Agents/chemistry ; Anti-Inflammatory Agents/pharmacology ; DNA/metabolism ; HEK293 Cells ; Humans ; Molecular Docking Simulation ; Molecular Sequence Data ; NF-kappa B/chemistry ; NF-kappa B/metabolism ; Protein Multimerization/drug effects ; Sequence Alignment ; Transcription Factor RelA/antagonists & inhibitors ; Transcription Factor RelA/chemistry ; Transcription Factor RelA/metabolism ; Withanolides/chemistry ; Withanolides/pharmacology
    Chemical Substances Anti-Inflammatory Agents ; NF-kappa B ; Transcription Factor RelA ; Withanolides ; DNA (9007-49-2) ; withaferin A (L6DO3QW4K5)
    Language English
    Publishing date 2016-04
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 779397-2
    ISSN 1098-5549 ; 0270-7306
    ISSN (online) 1098-5549
    ISSN 0270-7306
    DOI 10.1128/MCB.00895-15
    Database MEDical Literature Analysis and Retrieval System OnLINE

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