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Tariq M, Ikeya T, Togashi N, Fairall L, Kamei S, Mayooramurugan S, Abbott LR, Hasan A, Bueno-Alejo C, Sukegawa S, Romartinez-Alonso B, Muro Campillo MA, Hudson AJ, Ito Y, Schwabe JW, Dominguez C, Tanaka K. Structural insights into the complex of oncogenic KRas4B G12V and Rgl2, a RalA/B activator. Life Sci Alliance 2024; 7:e202302080. [PMID: 37833074 PMCID: PMC10576006 DOI: 10.26508/lsa.202302080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 09/28/2023] [Accepted: 10/02/2023] [Indexed: 10/15/2023] Open
Abstract
About a quarter of total human cancers carry mutations in Ras isoforms. Accumulating evidence suggests that small GTPases, RalA, and RalB, and their activators, Ral guanine nucleotide exchange factors (RalGEFs), play an essential role in oncogenic Ras-induced signalling. We studied the interaction between human KRas4B and the Ras association (RA) domain of Rgl2 (Rgl2RA), one of the RA-containing RalGEFs. We show that the G12V oncogenic KRas4B mutation changes the interaction kinetics with Rgl2RA The crystal structure of the KRas4BG12V: Rgl2RA complex shows a 2:2 heterotetramer where the switch I and switch II regions of each KRasG12V interact with both Rgl2RA molecules. This structural arrangement is highly similar to the HRasE31K:RALGDSRA crystal structure and is distinct from the well-characterised Ras:Raf complex. Interestingly, the G12V mutation was found at the dimer interface of KRas4BG12V with its partner. Our study reveals a potentially distinct mode of Ras:effector complex formation by RalGEFs and offers a possible mechanistic explanation for how the oncogenic KRas4BG12V hyperactivates the RalA/B pathway.
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Affiliation(s)
- Mishal Tariq
- https://ror.org/04h699437 Department of Molecular and Cell Biology, University of Leicester, Leicester, UK
| | - Teppei Ikeya
- https://ror.org/00ws30h19 Department of Chemistry, Tokyo Metropolitan University, Hachioji, Japan
| | - Naoyuki Togashi
- https://ror.org/00ws30h19 Department of Chemistry, Tokyo Metropolitan University, Hachioji, Japan
| | - Louise Fairall
- https://ror.org/04h699437 Department of Molecular and Cell Biology, University of Leicester, Leicester, UK
- https://ror.org/04h699437 Leicester Institute of Structure and Chemical Biology, University of Leicester, Leicester, UK
| | - Shun Kamei
- https://ror.org/00ws30h19 Department of Chemistry, Tokyo Metropolitan University, Hachioji, Japan
| | - Sannojah Mayooramurugan
- https://ror.org/04h699437 Department of Molecular and Cell Biology, University of Leicester, Leicester, UK
| | - Lauren R Abbott
- https://ror.org/04h699437 Department of Molecular and Cell Biology, University of Leicester, Leicester, UK
| | - Anab Hasan
- https://ror.org/04h699437 Department of Molecular and Cell Biology, University of Leicester, Leicester, UK
| | - Carlos Bueno-Alejo
- https://ror.org/04h699437 Leicester Institute of Structure and Chemical Biology, University of Leicester, Leicester, UK
| | - Sakura Sukegawa
- https://ror.org/00ws30h19 Department of Chemistry, Tokyo Metropolitan University, Hachioji, Japan
| | - Beatriz Romartinez-Alonso
- https://ror.org/04h699437 Department of Molecular and Cell Biology, University of Leicester, Leicester, UK
- https://ror.org/04h699437 Leicester Institute of Structure and Chemical Biology, University of Leicester, Leicester, UK
| | - Miguel Angel Muro Campillo
- https://ror.org/04h699437 Department of Molecular and Cell Biology, University of Leicester, Leicester, UK
| | - Andrew J Hudson
- https://ror.org/04h699437 Leicester Institute of Structure and Chemical Biology, University of Leicester, Leicester, UK
- https://ror.org/04h699437 Department of Chemistry, University of Leicester, Leicester, UK
| | - Yutaka Ito
- https://ror.org/00ws30h19 Department of Chemistry, Tokyo Metropolitan University, Hachioji, Japan
| | - John Wr Schwabe
- https://ror.org/04h699437 Department of Molecular and Cell Biology, University of Leicester, Leicester, UK
- https://ror.org/04h699437 Leicester Institute of Structure and Chemical Biology, University of Leicester, Leicester, UK
| | - Cyril Dominguez
- https://ror.org/04h699437 Department of Molecular and Cell Biology, University of Leicester, Leicester, UK
- https://ror.org/04h699437 Leicester Institute of Structure and Chemical Biology, University of Leicester, Leicester, UK
| | - Kayoko Tanaka
- https://ror.org/04h699437 Department of Molecular and Cell Biology, University of Leicester, Leicester, UK
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Orritt KM, Feng L, Newell JF, Sutton JN, Grossman S, Germe T, Abbott LR, Jackson HL, Bury BKL, Maxwell A, McPhillie MJ, Fishwick CWG. De novo design of type II topoisomerase inhibitors as potential antimicrobial agents targeting a novel binding region. RSC Med Chem 2022; 13:831-839. [PMID: 35919336 PMCID: PMC9298182 DOI: 10.1039/d2md00049k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 05/30/2022] [Indexed: 11/21/2022] Open
Abstract
By 2050, it is predicted that antimicrobial resistance will be responsible for 10 million global deaths annually, more deaths than cancer, costing the world economy $100 trillion. Clearly, strategies to address this problem are essential as bacterial evolution is rendering our current antibiotics ineffective. The discovery of an allosteric binding site on the established antibacterial target DNA gyrase offers a new medicinal chemistry strategy. As this site is distinct from the fluoroquinolone binding site, resistance is not yet documented. Using in silico molecular design methods, we have designed and synthesised a novel series of biphenyl-based inhibitors inspired by a published thiophene-based allosteric inhibitor. This series was evaluated in vitro against Escherichia coli DNA gyrase and E. coli topoisomerase IV with the most potent compounds exhibiting IC50 values towards the low micromolar range for DNA gyrase and only ∼2-fold less active against topoisomerase IV. The structure–activity relationships reported herein suggest insights to further exploit this allosteric site, offering a pathway to overcome developing fluoroquinolone resistance. A computational design, make and test strategy was used to identify antibacterial inhibitors of bacterial DNA gyrase and topoisomerase IV, proposed to bind at a novel allosteric site.![]()
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Affiliation(s)
- Kyle M. Orritt
- School of Chemistry, University of Leeds, Leeds, LS2 9JT, UK
| | - Lipeng Feng
- Dept. Biochemistry & Metabolism, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
| | | | - Jack N. Sutton
- School of Chemistry, University of Leeds, Leeds, LS2 9JT, UK
| | - Scott Grossman
- School of Chemistry, University of Leeds, Leeds, LS2 9JT, UK
| | - Thomas Germe
- Dept. Biochemistry & Metabolism, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
| | - Lauren R. Abbott
- Dept. Biochemistry & Metabolism, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
| | | | | | - Anthony Maxwell
- Dept. Biochemistry & Metabolism, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
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Bush NG, Diez-Santos I, Abbott LR, Maxwell A. Quinolones: Mechanism, Lethality and Their Contributions to Antibiotic Resistance. Molecules 2020; 25:E5662. [PMID: 33271787 PMCID: PMC7730664 DOI: 10.3390/molecules25235662] [Citation(s) in RCA: 116] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 11/27/2020] [Accepted: 11/28/2020] [Indexed: 12/05/2022] Open
Abstract
Fluoroquinolones (FQs) are arguably among the most successful antibiotics of recent times. They have enjoyed over 30 years of clinical usage and become essential tools in the armoury of clinical treatments. FQs target the bacterial enzymes DNA gyrase and DNA topoisomerase IV, where they stabilise a covalent enzyme-DNA complex in which the DNA is cleaved in both strands. This leads to cell death and turns out to be a very effective way of killing bacteria. However, resistance to FQs is increasingly problematic, and alternative compounds are urgently needed. Here, we review the mechanisms of action of FQs and discuss the potential pathways leading to cell death. We also discuss quinolone resistance and how quinolone treatment can lead to resistance to non-quinolone antibiotics.
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Affiliation(s)
| | | | | | - Anthony Maxwell
- Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK; (N.G.B.); (I.D.-S.); (L.R.A.)
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Bisson JI, van Deursen R, Hannigan B, Kitchiner N, Barawi K, Jones K, Pickles T, Skipper J, Young C, Abbott LR, van Gelderen M, Nijdam MJ, Vermetten E. Randomized controlled trial of multi-modular motion-assisted memory desensitization and reconsolidation (3MDR) for male military veterans with treatment-resistant post-traumatic stress disorder. Acta Psychiatr Scand 2020; 142:141-151. [PMID: 32495381 DOI: 10.1111/acps.13200] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/28/2020] [Indexed: 11/29/2022]
Abstract
OBJECTIVE To explore the potential efficacy of multi-modular motion-assisted memory desensitization and reprocessing (3MDR) in British military veterans with treatment-resistant service-related PTSD. METHODS Exploratory single-blind, randomized, parallel arm, cross-over controlled trial with nested process evaluation to assess fidelity, adherence and factors that influence outcome. RESULTS A total of 42 participants (all male) were randomized with 83% retention at 12 weeks and 86% at 26 weeks. The difference in mean Clinician-Administered PTSD Scale for DSM-5 scores between the immediate and delayed 3MDR arms was -9.38 (95% CI -17.33 to -1.44, P = 0.021) at 12 weeks and -3.59 (-14.39 to 7.20, P = 0.513) at 26 weeks when both groups had received 3MDR. The likely effect size of 3MDR was found to be 0.65. Improvements were maintained at 26-week follow-up. 3MDR was found to be acceptable to most, but not all, participants. Several factors that may impact efficacy and acceptability of 3MDR were identified. CONCLUSION 3MDR is a promising new intervention for treatment-resistant PTSD with emerging evidence of effect.
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Affiliation(s)
- J I Bisson
- School of Medicine, Cardiff University, Cardiff, UK
| | - R van Deursen
- School of Healthcare Sciences, Cardiff University, Cardiff, UK
| | - B Hannigan
- School of Healthcare Sciences, Cardiff University, Cardiff, UK
| | - N Kitchiner
- Veterans' NHS Wales, Cardiff and Vale University Health Board, Cardiff, UK
| | - K Barawi
- School of Medicine, Cardiff University, Cardiff, UK
| | - K Jones
- School of Healthcare Sciences, Cardiff University, Cardiff, UK
| | - T Pickles
- Centre for Trials Research, Cardiff University, Cardiff, UK
| | - J Skipper
- School of Medicine, Cardiff University, Cardiff, UK
| | - C Young
- Cardiff and Vale University Health Board, Cardiff, UK
| | - L R Abbott
- School of Healthcare Sciences, Cardiff University, Cardiff, UK
| | - M van Gelderen
- Department of Psychiatry, Leiden University Medical Center, Leiden, The Netherlands
| | - M J Nijdam
- ARQ Centrum'45, ARQ National Psychotrauma Centre, Diemen, The Netherlands.,Department of Psychiatry, Amsterdam University Medical Centres, Amsterdam, The Netherlands
| | - E Vermetten
- Department of Psychiatry, Leiden University Medical Center, Leiden, The Netherlands
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Cowan PJ, Tsang D, Pedic CM, Abbott LR, Shinkel TA, d'Apice AJ, Pearse MJ. The human ICAM-2 promoter is endothelial cell-specific in vitro and in vivo and contains critical Sp1 and GATA binding sites. J Biol Chem 1998; 273:11737-44. [PMID: 9565596 DOI: 10.1074/jbc.273.19.11737] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The expression of intercellular adhesion molecule 2 (ICAM-2) in adult tissues is restricted to vascular endothelial cells and megakaryocytes. We have previously shown that the endothelial-specific in vivo activity of the human ICAM-2 promoter is contained within a small (0.33-kilobase (kbp)) 5'-flanking region of the gene. Here we describe the in vitro characterization of this region. The ICAM-2 promoter is TATA-less, and transcription in endothelial cells initiates at four sites. Reporter gene expression directed by the promoter was 125-fold greater than vector alone in bovine aortic endothelial cells but less than 2-fold vector alone in non-endothelial (COS) cells, confirming that specificity in vivo was paralleled in vitro. The addition of 2.7 kbp of 5'-flanking region to the 0.33-kbp fragment had no effect on promoter activity or specificity. The mutation of an Sp1 motif centered at base pair -194 or an eight-base pair palindrome at -268 each reduced promoter activity by 70%. Mutation of GATA motifs at -145 and -53 reduced promoter activity by 78 and 61%, respectively. Specific binding of bovine aortic endothelial cells nuclear proteins to the Sp1 and GATA sites was demonstrated by gel shift analysis. Promoter activity in COS cells was transactivated 3-4-fold by overexpression of GATA-2. The results presented here suggest that transcription from the ICAM-2 promoter in endothelial cells is regulated by the interplay of several positive-acting factors and provide the basis for further analysis of endothelial-specific gene expression.
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Affiliation(s)
- P J Cowan
- Immunology Research Center, St Vincent's Hospital, Fitzroy 3065, Victoria, Australia
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Rubbo SD, Abbott LR. Filtration efficiency of surgical masks: a new method of evaluation. Aust N Z J Surg 1968; 38:80-3. [PMID: 5245839] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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