1
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Girard E, Lopes P, Spoerner M, Dhaussy AC, Prangé T, Kalbitzer HR, Colloc'h N. High Pressure Promotes Binding of the Allosteric Inhibitor Zn 2+-Cyclen in Crystals of Activated H-Ras. Chemistry 2024:e202400304. [PMID: 38647362 DOI: 10.1002/chem.202400304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Revised: 04/18/2024] [Accepted: 04/22/2024] [Indexed: 04/25/2024]
Abstract
In this work, we experimentally investigate the potency of high pressure to drive a protein toward an excited state where an inhibitor targeted for this state can bind. Ras proteins are small GTPases cycling between active GTP-bound and inactive GDP-bound states. Various states of GTP-bound Ras in active conformation coexist in solution, amongst them, state 2 which binds to effectors, and state 1, weakly populated at ambient conditions, which has a low affinity for effectors. Zn2+-cyclen is an allosteric inhibitor of Ras protein, designed to bind specifically to the state 1. In H-Ras(wt).Mg2+.GppNHp crystals soaked with Zn2+-cyclen, no binding could be observed, as expected in the state 2 conformation which is the dominant state at ambient pressure. Interestingly, Zn2+-cyclen binding is observed at 500 MPa pressure, close to the nucleotide, in Ras protein that is driven by pressure to a state 1 conformer. The unknown binding mode of Zn2+-cyclen to H-Ras can thus be fully characterized in atomic details. As a more general conjunction from our study, high pressure x-ray crystallography turns out to be a powerful method to induce transitions allowing drug binding in proteins that are in low-populated conformations at ambient conditions, enabling the design of specific inhibitors.
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Affiliation(s)
- Eric Girard
- CEA, CNRS, IBS, Univ. Grenoble Alpes, Grenoble, France
| | - Pedro Lopes
- Institute for Biophysics and Physical Biochemistry, University of Regensburg, Regensburg, Germany
| | - Michael Spoerner
- Institute for Biophysics and Physical Biochemistry, University of Regensburg, Regensburg, Germany
| | | | - Thierry Prangé
- CiTCoM, CNRS, Faculté de Pharmacie, Université de Paris-Cité, Paris, France
| | - Hans Robert Kalbitzer
- Institute for Biophysics and Physical Biochemistry, University of Regensburg, Regensburg, Germany
| | - Nathalie Colloc'h
- ISTCT UMR6030, Centre Cyceron, CNRS - Université de Caen Normandie - Normandie Université, Caen, France
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2
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Hu F, Wang Y, Zeng J, Deng X, Xia F, Xu X. Unveiling the State Transition Mechanisms of Ras Proteins through Enhanced Sampling and QM/MM Simulations. J Phys Chem B 2024; 128:1418-1427. [PMID: 38323538 DOI: 10.1021/acs.jpcb.3c07666] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2024]
Abstract
In cells, wild-type RasGTP complexes exist in two distinct states: active State 2 and inactive State 1. These complexes regulate their functions by transitioning between the two states. However, the mechanisms underlying this state transition have not been clearly elucidated. To address this, we conducted a detailed simulation study to characterize the energetics of the stable states involved in the state transitions of the HRasGTP complex, specifically from State 2 to State 1. This was achieved by employing multiscale quantum mechanics/molecular mechanics and enhanced sampling molecular dynamics methods. Based on the simulation results, we constructed the two-dimensional free energy landscapes that provide crucial information about the conformational changes of the HRasGTP complex from State 2 to State 1. Furthermore, we also explored the conformational changes from the intermediate state to the product state during guanosine triphosphate hydrolysis. This study on the conformational changes involved in the HRas state transitions serves as a valuable reference for understanding the corresponding events of both KRas and NRas as well.
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Affiliation(s)
- Fangchen Hu
- School of Chemistry and Molecular Engineering, East China Normal University, Shanghai 200062, China
| | - Yiqiu Wang
- School of Chemistry and Molecular Engineering, East China Normal University, Shanghai 200062, China
| | - Juan Zeng
- School of Biomedical Engineering, Guangdong Medical University, Dongguan 523808, China
| | - Xianming Deng
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Fei Xia
- School of Chemistry and Molecular Engineering, East China Normal University, Shanghai 200062, China
| | - Xin Xu
- Collaborative Innovation Center of Chemistry for Energy Materials, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, MOE Key Laboratory of Computational Physical Sciences, Department of Chemistry, Fudan University, Shanghai 200433, China
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3
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Sharma AK, Pei J, Yang Y, Dyba M, Smith B, Rabara D, Larsen EK, Lightstone FC, Esposito D, Stephen AG, Wang B, Beltran PJ, Wallace E, Nissley DV, McCormick F, Maciag AE. Revealing the mechanism of action of a first-in-class covalent inhibitor of KRASG12C (ON) and other functional properties of oncogenic KRAS by 31P NMR. J Biol Chem 2024; 300:105650. [PMID: 38237681 PMCID: PMC10877953 DOI: 10.1016/j.jbc.2024.105650] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 12/27/2023] [Accepted: 12/29/2023] [Indexed: 02/17/2024] Open
Abstract
Individual oncogenic KRAS mutants confer distinct differences in biochemical properties and signaling for reasons that are not well understood. KRAS activity is closely coupled to protein dynamics and is regulated through two interconverting conformations: state 1 (inactive, effector binding deficient) and state 2 (active, effector binding enabled). Here, we use 31P NMR to delineate the differences in state 1 and state 2 populations present in WT and common KRAS oncogenic mutants (G12C, G12D, G12V, G13D, and Q61L) bound to its natural substrate GTP or a commonly used nonhydrolyzable analog GppNHp (guanosine-5'-[(β,γ)-imido] triphosphate). Our results show that GppNHp-bound proteins exhibit significant state 1 population, whereas GTP-bound KRAS is primarily (90% or more) in state 2 conformation. This observation suggests that the predominance of state 1 shown here and in other studies is related to GppNHp and is most likely nonexistent in cells. We characterize the impact of this differential conformational equilibrium of oncogenic KRAS on RAF1 kinase effector RAS-binding domain and intrinsic hydrolysis. Through a KRAS G12C drug discovery, we have identified a novel small-molecule inhibitor, BBO-8956, which is effective against both GDP- and GTP-bound KRAS G12C. We show that binding of this inhibitor significantly perturbs state 1-state 2 equilibrium and induces an inactive state 1 conformation in GTP-bound KRAS G12C. In the presence of BBO-8956, RAF1-RAS-binding domain is unable to induce a signaling competent state 2 conformation within the ternary complex, demonstrating the mechanism of action for this novel and active-conformation inhibitor.
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Affiliation(s)
- Alok K Sharma
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc, Frederick, Maryland, USA.
| | - Jun Pei
- Physical and Life Sciences (PLS) Directorate, Lawrence Livermore National Laboratory, Livermore, California, USA
| | - Yue Yang
- Physical and Life Sciences (PLS) Directorate, Lawrence Livermore National Laboratory, Livermore, California, USA
| | - Marcin Dyba
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc, Frederick, Maryland, USA
| | - Brian Smith
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc, Frederick, Maryland, USA
| | - Dana Rabara
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc, Frederick, Maryland, USA
| | - Erik K Larsen
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc, Frederick, Maryland, USA
| | - Felice C Lightstone
- Physical and Life Sciences (PLS) Directorate, Lawrence Livermore National Laboratory, Livermore, California, USA
| | - Dominic Esposito
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc, Frederick, Maryland, USA
| | - Andrew G Stephen
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc, Frederick, Maryland, USA
| | - Bin Wang
- BridgeBio Oncology Therapeutics, BridgeBio Pharma, Inc, Palo Alto, California, USA
| | - Pedro J Beltran
- BridgeBio Oncology Therapeutics, BridgeBio Pharma, Inc, Palo Alto, California, USA
| | - Eli Wallace
- BridgeBio Oncology Therapeutics, BridgeBio Pharma, Inc, Palo Alto, California, USA
| | - Dwight V Nissley
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc, Frederick, Maryland, USA
| | - Frank McCormick
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc, Frederick, Maryland, USA; BridgeBio Oncology Therapeutics, BridgeBio Pharma, Inc, Palo Alto, California, USA; Helen Diller Family Comprehensive Cancer Center, University of California San Francisco, San Francisco, California, USA
| | - Anna E Maciag
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc, Frederick, Maryland, USA.
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4
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Chan AH, Simanshu DK. Crystallographic Studies of KRAS in Complex with Small Molecules and RAS-Binding Proteins. Methods Mol Biol 2024; 2797:47-65. [PMID: 38570452 DOI: 10.1007/978-1-0716-3822-4_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/05/2024]
Abstract
RAS proteins play a vital role in regulating downstream signaling and essential cellular processes, positioning them as key players in normal cellular physiology and disease development. Among the various isoforms of RAS, KRAS stands out as one of the most frequently mutated genes in human cancer. The prevalence of RAS mutations in cancer often involves single amino acid substitutions at codons 12, 13, or 61. These mutations disrupt the RAS protein's inherent ability to transition between its active and inactive states, resulting in a constant activation signal and driving uncontrolled cell growth. Crystallization and structural analysis of KRAS with inhibitors and RAS-binding proteins play a pivotal role in unraveling the structural and mechanistic details of KRAS function, aiding in drug discovery efforts, and advancing our understanding of KRAS-driven diseases. Here, we present our experimental methodology for crystallizing KRAS in the presence of covalent or non-covalent small molecules and proteins acting as effectors or regulators of RAS. We detail the techniques for successful crystallization and the subsequent optimization of crystallization conditions. The resulting crystals and their structures will provide valuable insights into the key interactions between KRAS and its partner proteins or potential inhibitors, offering a foundation for developing targeted therapies that are more potent and selective against KRAS-driven cancers.
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Affiliation(s)
- Albert H Chan
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Dhirendra K Simanshu
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, MD, USA.
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5
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Larsen EK, Abreu-Blanco M, Rabara D, Stephen AG. KRAS4b:RAF-1 Homogenous Time-Resolved Fluorescence Resonance Energy Transfer Assay for Drug Discovery. Methods Mol Biol 2024; 2797:159-175. [PMID: 38570459 DOI: 10.1007/978-1-0716-3822-4_12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/05/2024]
Abstract
Homogenous time-resolved FRET (HTRF) assays have become one of the most popular tools for pharmaceutical drug screening efforts over the last two decades. Large Stokes shifts and long fluorescent lifetimes of lanthanide chelates lead to robust signal to noise, as well as decreased false positive rates compared to traditional assay techniques. In this chapter, we describe an HTRF protein-protein interaction (PPI) assay for the KRAS4b G-domain in the GppNHp-bound state and the RAF-1-RBD currently used for drug screens. Application of this assay contributes to the identification of lead compounds targeting the GTP-bound active state of K-RAS.
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Affiliation(s)
- Erik K Larsen
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, MD, USA.
| | - Maria Abreu-Blanco
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Dana Rabara
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Andrew G Stephen
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
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6
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Chao FA, Chan AH, Dharmaiah S, Schwieters CD, Tran TH, Taylor T, Ramakrishnan N, Esposito D, Nissley DV, McCormick F, Simanshu DK, Cornilescu G. Reduced dynamic complexity allows structure elucidation of an excited state of KRAS G13D. Commun Biol 2023; 6:594. [PMID: 37268708 DOI: 10.1038/s42003-023-04960-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2023] [Accepted: 05/19/2023] [Indexed: 06/04/2023] Open
Abstract
Localized dynamics of RAS, including regions distal to the nucleotide-binding site, is of high interest for elucidating the mechanisms by which RAS proteins interact with effectors and regulators and for designing inhibitors. Among several oncogenic mutants, methyl relaxation dispersion experiments reveal highly synchronized conformational dynamics in the active (GMPPNP-bound) KRASG13D, which suggests an exchange between two conformational states in solution. Methyl and 31P NMR spectra of active KRASG13D in solution confirm a two-state ensemble interconverting on the millisecond timescale, with a major Pγ atom peak corresponding to the dominant State 1 conformation and a secondary peak indicating an intermediate state different from the known State 2 conformation recognized by RAS effectors. High-resolution crystal structures of active KRASG13D and KRASG13D-RAF1 RBD complex provide snapshots of the State 1 and 2 conformations, respectively. We use residual dipolar couplings to solve and cross-validate the structure of the intermediate state of active KRASG13D, showing a conformation distinct from those of States 1 and 2 outside the known flexible switch regions. The dynamic coupling between the conformational exchange in the effector lobe and the breathing motion in the allosteric lobe is further validated by a secondary mutation in the allosteric lobe, which affects the conformational population equilibrium.
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Affiliation(s)
- Fa-An Chao
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Frederick, MD, 21701, USA.
| | - Albert H Chan
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Frederick, MD, 21701, USA
| | - Srisathiyanarayanan Dharmaiah
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Frederick, MD, 21701, USA
| | - Charles D Schwieters
- Division of Computational Bioscience, Center for Information Technology, National Institutes of Health, Building 12A, 20892-5624, Bethesda, MD, USA
| | - Timothy H Tran
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Frederick, MD, 21701, USA
| | - Troy Taylor
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Frederick, MD, 21701, USA
| | - Nitya Ramakrishnan
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Frederick, MD, 21701, USA
| | - Dominic Esposito
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Frederick, MD, 21701, USA
| | - Dwight V Nissley
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Frederick, MD, 21701, USA
| | - Frank McCormick
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Frederick, MD, 21701, USA
- Helen Diller Family Comprehensive Cancer Center, University of California San Francisco, 1450 3rd Street, San Francisco, CA, 94158, USA
| | - Dhirendra K Simanshu
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Frederick, MD, 21701, USA.
| | - Gabriel Cornilescu
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Frederick, MD, 21701, USA.
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7
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Pálfy G, Menyhárd DK, Ákontz‐Kiss H, Vida I, Batta G, Tőke O, Perczel A. The Importance of Mg 2+ -Free State in Nucleotide Exchange of Oncogenic K-Ras Mutants. Chemistry 2022; 28:e202201449. [PMID: 35781716 PMCID: PMC9804424 DOI: 10.1002/chem.202201449] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Indexed: 01/05/2023]
Abstract
For efficient targeting of oncogenic K-Ras interaction sites, a mechanistic picture of the Ras-cycle is necessary. Herein, we used NMR relaxation techniques and molecular dynamics simulations to decipher the role of slow dynamics in wild-type and three oncogenic P-loop mutants of K-Ras. Our measurements reveal a dominant two-state conformational exchange on the ms timescale in both GDP- and GTP-bound K-Ras. The identified low-populated higher energy state in GDP-loaded K-Ras has a conformation reminiscent of a nucleotide-bound/Mg2+ -free state characterized by shortened β2/β3-strands and a partially released switch-I region preparing K-Ras for the interaction with the incoming nucleotide exchange factor and subsequent reactivation. By providing insight into mutation-specific differences in K-Ras structural dynamics, our systematic analysis improves our understanding of prolonged K-Ras signaling and may aid the development of allosteric inhibitors targeting nucleotide exchange in K-Ras.
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Affiliation(s)
- Gyula Pálfy
- Laboratory of Structural Chemistry and BiologyInstitute of ChemistryEötvös Loránd University1/a Pázmány Péter stny.Budapest1117Hungary,MTA-ELTE Protein Modeling Research GroupEötvös Loránd Research Network (ELKH)1/a Pázmány Péter stny.Budapest1117Hungary
| | - Dóra K. Menyhárd
- MTA-ELTE Protein Modeling Research GroupEötvös Loránd Research Network (ELKH)1/a Pázmány Péter stny.Budapest1117Hungary
| | - Hanna Ákontz‐Kiss
- Laboratory of Structural Chemistry and BiologyInstitute of ChemistryEötvös Loránd University1/a Pázmány Péter stny.Budapest1117Hungary,Hevesy György PhD School of ChemistryEötvös Loránd University1/a Pázmány Péter stny.Budapest1117Hungary
| | - István Vida
- Laboratory of Structural Chemistry and BiologyInstitute of ChemistryEötvös Loránd University1/a Pázmány Péter stny.Budapest1117Hungary,Hevesy György PhD School of ChemistryEötvös Loránd University1/a Pázmány Péter stny.Budapest1117Hungary
| | - Gyula Batta
- Structural Biology Research GroupDepartment of Organic ChemistryUniversity of Debrecen1 Egyetem térDebrecen4032Hungary
| | - Orsolya Tőke
- Laboratory for NMR SpectroscopyResearch Centre for Natural Sciences (RCNS)2 Magyar tudósok körútjaBudapest1117Hungary
| | - András Perczel
- Laboratory of Structural Chemistry and BiologyInstitute of ChemistryEötvös Loránd University1/a Pázmány Péter stny.Budapest1117Hungary,MTA-ELTE Protein Modeling Research GroupEötvös Loránd Research Network (ELKH)1/a Pázmány Péter stny.Budapest1117Hungary
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8
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Zeng J, Chen J, Xia F, Cui Q, Deng X, Xu X. Identification of functional substates of KRas during GTP hydrolysis with enhanced sampling simulations. Phys Chem Chem Phys 2022; 24:7653-7665. [PMID: 35297922 PMCID: PMC8972078 DOI: 10.1039/d2cp00274d] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
As the hub of major signaling pathways, Ras proteins are implicated in 19% of tumor-caused cancers due to perturbations in their conformational and/or catalytic properties. Despite numerous studies, the functions of the conformational substates for the most important isoform, KRas, remain elusive. In this work, we perform an extensive simulation analysis on the conformational landscape of KRas in its various chemical states during the GTP hydrolysis cycle: the reactant state KRasGTP·Mg2+, the intermediate state KRasGDP·Pi·Mg2+ and the product state KRasGDP·Mg2+. The results from enhanced sampling simulations reveal that State 1 of KRasGTP·Mg2+ has multiple stable substates in solution, one of which might account for interacting with GEFs. State 2 of KRasGTP·Mg2+ features two substates "Tyr32in" and "Tyr32out", which are poised to interact with effectors and GAPs, respectively. For the intermediate state KRasGDP·Pi·Mg2+, Gln61 and Pi are found to assume a broad set of conformations, which might account for the weak oncogenic effect of Gln61 mutations in KRas in contrast to the situation in HRas and NRas. Finally, the product state KRasGDP·Mg2+ has more than two stable substates in solution, pointing to a conformation-selection mechanism for complexation with GEFs. Based on these results, some specific inhibition strategies for targeting the binding sites of the high-energy substates of KRas during GTP hydrolysis are discussed.
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Affiliation(s)
- Juan Zeng
- School of Biomedical Engineering, Guangdong Medical University, Dongguan 523808, China
| | - Jian Chen
- School of Chemistry and Molecular Engineering, NYU-ECNU Center for Computational Chemistry at NYU Shanghai, East China Normal University, Shanghai 200062, China.
| | - Fei Xia
- School of Chemistry and Molecular Engineering, NYU-ECNU Center for Computational Chemistry at NYU Shanghai, East China Normal University, Shanghai 200062, China.
| | - Qiang Cui
- Departments of Chemistry, Physics and Biomedical Engineering, Boston University, 590 Commonwealth Avenue, Boston, MA 02215, USA
| | - Xianming Deng
- State Key Laboratory of Cellular Stress Biology Innovation Center for Cell Signaling Network, School of Life Sciences, Xiamen University, Fujian 361101, China.
| | - Xin Xu
- Collaborative Innovation Center of Chemistry for Energy Materials, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, MOE Key Laboratory of Computational Physical Sciences, Department of Chemistry, Fudan University, Shanghai 200433, China.
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9
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Xiong Y, Zeng J, Xia F, Cui Q, Deng X, Xu X. Conformations and binding pockets of HRas and its guanine nucleotide exchange factors complexes in the guanosine triphosphate exchange process. J Comput Chem 2022; 43:906-916. [PMID: 35324017 PMCID: PMC9191747 DOI: 10.1002/jcc.26846] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2022] [Revised: 03/03/2022] [Accepted: 03/04/2022] [Indexed: 12/23/2022]
Abstract
The human Son of Sevenless (SOS) activates the signal-transduction protein Ras by forming the complex SOS·Ras and accelerating the guanosine triphosphate (GTP) exchange in Ras. Inhibition of SOS·Ras could regulate the function of Ras in cells and has emerged as an effective strategy for battling Ras related cancers. A key factor to the success of this approach is to understand the conformational change of Ras during the GTP exchange process. In this study, we perform an extensive molecular dynamics simulation to characterize the specific conformations of Ras without and with guanine nucleotide exchange factors (GEFs) of SOS, especially for the substates of State 1 of HRasGTP∙Mg2+ . The potent binding pockets on the surfaces of the RasGDP∙Mg2+ , the S1.1 and S1.2 substates in State 1 of RasGTP∙Mg2+ and the ternary complexes with SOS are predicted, including the binding sites of other domains of SOS. These findings help to obtain a more thorough understanding of Ras functions in the GTP cycling process and provide a structural foundation for future drug design.
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Affiliation(s)
- Yuqing Xiong
- School of Chemistry and Molecular Engineering, NYU-ECNU Center for Computational Chemistry at NYU Shanghai, East China Normal University, Shanghai, China
| | - Juan Zeng
- School of Biomedical Engineering, Guangdong Medical University, Dongguan, China
| | - Fei Xia
- School of Chemistry and Molecular Engineering, NYU-ECNU Center for Computational Chemistry at NYU Shanghai, East China Normal University, Shanghai, China
| | - Qiang Cui
- Departments of Chemistry, Physics and Biomedical Engineering, Boston University, Boston, Massachusetts, USA
| | - Xianming Deng
- State Key Laboratory of Cellular Stress Biology, Innovation Center for Cell Signaling Network, School of Life Sciences, Xiamen University, Xiamen, China
| | - Xin Xu
- Collaborative Innovation Center of Chemistry for Energy Materials, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, MOE Key Laboratory of Computational Physical Sciences, Departments of Chemistry, Fudan University, Shanghai, China
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10
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Chao FA, Dharmaiah S, Taylor T, Messing S, Gillette W, Esposito D, Nissley DV, McCormick F, Byrd RA, Simanshu DK, Cornilescu G. Insights into the Cross Talk between Effector and Allosteric Lobes of KRAS from Methyl Conformational Dynamics. J Am Chem Soc 2022; 144:4196-4205. [PMID: 35213144 PMCID: PMC10430694 DOI: 10.1021/jacs.2c00007] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
KRAS is the most frequently mutated RAS protein in cancer patients, and it is estimated that about 20% of the cancer patients in the United States carried mutant RAS proteins. To accelerate therapeutic development, structures and dynamics of RAS proteins had been extensively studied by various biophysical techniques for decades. Although 31P NMR studies revealed population equilibrium of the two major states in the active GMPPNP-bound form, more complex conformational dynamics in RAS proteins and oncogenic mutants subtly modulate the interactions with their downstream effectors. We established a set of customized NMR relaxation dispersion techniques to efficiently and systematically examine the ms-μs conformational dynamics of RAS proteins. This method allowed us to observe varying synchronized motions that connect the effector and allosteric lobes in KRAS. We demonstrated the role of conformational dynamics of KRAS in controlling its interaction with the Ras-binding domain of the downstream effector RAF1, the first kinase in the MAPK pathway. This allows one to explain, as well as to predict, the altered binding affinities of various KRAS mutants, which was neither previously reported nor apparent from the structural perspective.
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Affiliation(s)
- Fa-An Chao
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Frederick, Maryland 21701, United States
| | - Srisathiyanarayanan Dharmaiah
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Frederick, Maryland 21701, United States
| | - Troy Taylor
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Frederick, Maryland 21701, United States
| | - Simon Messing
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Frederick, Maryland 21701, United States
| | - William Gillette
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Frederick, Maryland 21701, United States
| | - Dominic Esposito
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Frederick, Maryland 21701, United States
| | - Dwight V Nissley
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Frederick, Maryland 21701, United States
| | - Frank McCormick
- Helen Diller Family Comprehensive Cancer Center, University of California San Francisco, 1450 3rd Street, San Francisco, California 94158, United States
| | - R Andrew Byrd
- Center for Structural Biology, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
| | - Dhirendra K Simanshu
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Frederick, Maryland 21701, United States
| | - Gabriel Cornilescu
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Frederick, Maryland 21701, United States
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11
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Girard E, Lopes P, Spoerner M, Dhaussy AC, Prangé T, Kalbitzer HR, Colloc'h N. Equilibria between conformational states of the Ras oncogene protein revealed by high pressure crystallography. Chem Sci 2022; 13:2001-2010. [PMID: 35308861 PMCID: PMC8848853 DOI: 10.1039/d1sc05488k] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Accepted: 01/12/2022] [Indexed: 01/04/2023] Open
Abstract
In this work, we experimentally investigate the allosteric transitions between conformational states on the Ras oncogene protein using high pressure crystallography. Ras protein is a small GTPase involved in central regulatory processes occurring in multiple conformational states. Ras acts as a molecular switch between active GTP-bound, and inactive GDP-bound states, controlling essential signal transduction pathways. An allosteric network of interactions between the effector binding regions and the membrane interacting regions is involved in Ras cycling. The conformational states which coexist simultaneously in solution possess higher Gibbs free energy than the ground state. Equilibria between these states can be shifted by applying pressure favouring conformations with lower partial molar volume, and has been previously analyzed by high-pressure NMR spectroscopy. High-pressure macromolecular crystallography (HPMX) is a powerful tool perfectly complementary to high-pressure NMR, allowing characterization at the molecular level with a high resolution the different allosteric states involved in the Ras cycling. We observe a transition above 300 MPa in the crystal leading to more stable conformers. Thus, we compare the crystallographic structures of Ras(wt)·Mg2+·GppNHp and Ras(D33K)·Mg2+·GppNHp at various high hydrostatic pressures. This gives insight into per-residue descriptions of the structural plasticity involved in allosteric equilibria between conformers. We have mapped out at atomic resolution the different segments of Ras protein which remain in the ground-state conformation or undergo structural changes, adopting excited-energy conformations corresponding to transient intermediate states. Such in crystallo phase transitions induced by pressure open the possibility to finely explore the structural determinants related to switching between Ras allosteric sub-states without any mutations nor exogenous partners. The equilibria between structural states induced by pressure within the crystal structure of Ras are illustrated with different colors corresponding to different Ras substates.![]()
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Affiliation(s)
- Eric Girard
- Univ. Grenoble Alpes, CEA, CNRS, IBS, Grenoble, France
| | - Pedro Lopes
- Institute of Biophysics and Physical Biochemistry, Centre of Magnetic Resonance in Chemistry and Biomedicine, University of Regensburg, Regensburg, Germany
| | - Michael Spoerner
- Institute of Biophysics and Physical Biochemistry, Centre of Magnetic Resonance in Chemistry and Biomedicine, University of Regensburg, Regensburg, Germany
| | | | - Thierry Prangé
- CiTCoM UMR 8038, CNRS Université de Paris, Faculté de Pharmacie, Paris, France
| | - Hans Robert Kalbitzer
- Institute of Biophysics and Physical Biochemistry, Centre of Magnetic Resonance in Chemistry and Biomedicine, University of Regensburg, Regensburg, Germany
| | - Nathalie Colloc'h
- ISTCT UMR 6030, CNRS, Université de Caen Normandie, CERVOxy Group, Centre Cyceron, Caen, France
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12
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Chen J, Zhang S, Wang W, Pang L, Zhang Q, Liu X. Mutation-Induced Impacts on the Switch Transformations of the GDP- and GTP-Bound K-Ras: Insights from Multiple Replica Gaussian Accelerated Molecular Dynamics and Free Energy Analysis. J Chem Inf Model 2021; 61:1954-1969. [PMID: 33739090 DOI: 10.1021/acs.jcim.0c01470] [Citation(s) in RCA: 79] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Mutations yield significant effect on the structural flexibility of two switch domains, SW1 and SW2, in K-Ras, which is considered as an important target of anticancer drug design. To unveil a molecular mechanism with regard to mutation-mediated tuning on the activity of K-Ras, multiple replica Gaussian accelerated molecular dynamics (MR-GaMD) simulations followed by analysis of free energy landscapes (FELs) are performed on the GDP- and GTP-bound wild-type (WT), G12V, and D33E K-Ras. The results suggest that G12V and D33E not only evidently change the flexibility of SW1 and SW2 but also greatly affect correlated motions of SW1 and SW2 separately relative to the P-loop and SW1, which exerts a certain tuning on the activity of K-Ras. The information stemming from the analyses of FELs reveals that the conformations of SW1 and SW2 are in high disorders in the GDP- and GTP-associated WT and mutated K-Ras, possibly producing significant effect on binding of guanine nucleotide exchange factors or effectors to K-Ras. The interaction networks of GDP and GTP with K-Ras are identified and the results uncover that the instability in hydrogen-bonding interactions of SW1 with GDP and GTP is mostly responsible for conformational disorder of SW1 and SW2 as well as tunes the activity of oncogenic K-Ras.
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Affiliation(s)
- Jianzhong Chen
- School of Science, Shandong Jiaotong University, Jinan 250357, China
| | - Shaolong Zhang
- School of Physics and Electronics, Shandong Normal University, Jinan, 250358, China
| | - Wei Wang
- School of Science, Shandong Jiaotong University, Jinan 250357, China
| | - Laixue Pang
- School of Science, Shandong Jiaotong University, Jinan 250357, China
| | - Qinggang Zhang
- School of Physics and Electronics, Shandong Normal University, Jinan, 250358, China
| | - Xinguo Liu
- School of Physics and Electronics, Shandong Normal University, Jinan, 250358, China
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13
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Lin Y, Lu S, Zhang J, Zheng Y. Structure of an inactive conformation of GTP-bound RhoA GTPase. Structure 2021; 29:553-563.e5. [PMID: 33497604 DOI: 10.1016/j.str.2020.12.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 11/22/2020] [Accepted: 12/23/2020] [Indexed: 12/12/2022]
Abstract
By using 31P NMR, we present evidence that the Rho family GTPase RhoA, similar to Ras GTPases, exists in an equilibrium of conformations when bound to GTP. High-resolution crystal structures of RhoA bound to the GTP analog GMPPNP and to GDP show that they display a similar overall inactive conformation. In contrast to the previously reported crystal structures of GTP analog-bound forms of two RhoA dominantly active mutants (G14V and Q63L), GMPPNP-bound RhoA assumes an open conformation in the Switch I loop with a previously unseen interaction between the γ-phosphate and Pro36, instead of the canonical Thr37. Molecular dynamics simulations found that the oncogenic RhoAG14V mutant displays a reduced flexibility in the Switch regions, consistent with a crystal structure of GDP-bound RhoAG14V. Thus, GDP- and GTP-bound RhoA can present similar inactive conformations, and the molecular dynamics in the Switch regions are likely to have a role in RhoA activation.
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Affiliation(s)
- Yuan Lin
- Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, 3333 Burnet Avenue, Cincinnati, OH 45229, USA
| | - Shaoyong Lu
- Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, 280 Chongqing South Road, Shanghai 200025, China
| | - Jian Zhang
- Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, 280 Chongqing South Road, Shanghai 200025, China
| | - Yi Zheng
- Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, 3333 Burnet Avenue, Cincinnati, OH 45229, USA.
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14
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Pálfy G, Menyhárd DK, Perczel A. Dynamically encoded reactivity of Ras enzymes: opening new frontiers for drug discovery. Cancer Metastasis Rev 2020; 39:1075-1089. [PMID: 32815102 PMCID: PMC7680338 DOI: 10.1007/s10555-020-09917-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Accepted: 06/22/2020] [Indexed: 12/11/2022]
Abstract
Decoding molecular flexibility in order to understand and predict biological processes-applying the principles of dynamic-structure-activity relationships (DSAR)-becomes a necessity when attempting to design selective and specific inhibitors of a protein that has overlapping interaction surfaces with its upstream and downstream partners along its signaling cascade. Ras proteins are molecular switches that meet this definition perfectly. The close-lying P-loop and the highly flexible switch I and switch II regions are the site of nucleotide-, assisting-, and effector-protein binding. Oncogenic mutations that also appear in this region do not cause easily characterized overall structural changes, due partly to the inherent conformational heterogeneity and pliability of these segments. In this review, we present an overview of the results obtained using approaches targeting Ras dynamics, such as nuclear magnetic resonance (NMR) measurements and experiment-based modeling calculations (mostly molecular dynamics (MD) simulations). These methodologies were successfully used to decipher the mutant- and isoform-specific nature of certain transient states, far-lying allosteric sites, and the internal interaction networks, as well as the interconnectivity of the catalytic and membrane-binding regions. This opens new therapeutic potential: the discovered interaction hotspots present hitherto not targeted, selective sites for drug design efforts in diverse locations of the protein matrix.
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Affiliation(s)
- Gyula Pálfy
- Laboratory of Structural Chemistry and Biology, Institute of Chemistry, ELTE, Eötvös Loránd University, Pázmány Péter sétány 1/A, 1117, Budapest, Hungary
- Protein Modeling Group HAS-ELTE, Institute of Chemistry, Eötvös Loránd University, P.O.B. 32, Budapest, 1538, Hungary
| | - Dóra K Menyhárd
- Laboratory of Structural Chemistry and Biology, Institute of Chemistry, ELTE, Eötvös Loránd University, Pázmány Péter sétány 1/A, 1117, Budapest, Hungary.
- Protein Modeling Group HAS-ELTE, Institute of Chemistry, Eötvös Loránd University, P.O.B. 32, Budapest, 1538, Hungary.
| | - András Perczel
- Laboratory of Structural Chemistry and Biology, Institute of Chemistry, ELTE, Eötvös Loránd University, Pázmány Péter sétány 1/A, 1117, Budapest, Hungary.
- Protein Modeling Group HAS-ELTE, Institute of Chemistry, Eötvös Loránd University, P.O.B. 32, Budapest, 1538, Hungary.
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15
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Chen X, Gao H, Long D. Millisecond Allosteric Dynamics of Activated Ras Reproduced with a Slowly Hydrolyzable GTP Analogue. Chembiochem 2020; 22:1079-1083. [PMID: 33140496 DOI: 10.1002/cbic.202000698] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 11/01/2020] [Indexed: 12/29/2022]
Abstract
The millisecond timescale dynamics of activated Ras transiently sample a low-populated conformational state that has distinct surface property from the major state and represents a promising target for binding of small-molecule compounds. To avoid the complications of hydrolysis, dynamics and other properties of active Ras have so far been routinely investigated by using non-hydrolyzable GTP analogues, which, however, were previously reported to alter both the kinetics and distribution of the conformational exchange. In this study, we quantitatively measured and validated the internal dynamics of Ras complexed with a slowly hydrolyzable GTP analogue, GTPγS, which increases the lifetime of active Ras by 23 times relative to that of native GTP. It was found that GTPγS, in addition to its better mimicking of the exchange kinetics than the commonly used non-hydrolyzable analogues GppNHp and GppCH2 p, can rigorously reproduce the natural dynamics network in active Ras, thus indicating its fitness for use in the development of allosteric inhibitors.
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Affiliation(s)
- Xiaomin Chen
- Hefei National Laboratory for Physical Sciences at the Microscale, MOE Key Laboratory for Membraneless Organelles & Cellular Dynamics, and School of Life Sciences, University of Science and Technology of China, 443 Huangshan Street, Hefei, Anhui, 230027, P. R. China
| | - Hexuan Gao
- Hefei National Laboratory for Physical Sciences at the Microscale, MOE Key Laboratory for Membraneless Organelles & Cellular Dynamics, and School of Life Sciences, University of Science and Technology of China, 443 Huangshan Street, Hefei, Anhui, 230027, P. R. China
| | - Dong Long
- Hefei National Laboratory for Physical Sciences at the Microscale, MOE Key Laboratory for Membraneless Organelles & Cellular Dynamics, and School of Life Sciences, University of Science and Technology of China, 443 Huangshan Street, Hefei, Anhui, 230027, P. R. China.,Department of Chemistry, University of Science and Technology of China Hefei, Anhui 230026, P. R. China
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16
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Coban MA, Fraga S, Caulfield TR. Structural And Computational Perspectives of Selectively Targeting Mutant Proteins. Curr Drug Discov Technol 2020; 18:365-378. [PMID: 32160847 DOI: 10.2174/1570163817666200311114819] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Revised: 01/24/2020] [Accepted: 01/28/2020] [Indexed: 11/22/2022]
Abstract
Diseases are often caused by mutant proteins. Many drugs have limited effectiveness and/or toxic side effects because of a failure to selectively target the disease-causing mutant variant, rather than the functional wild type protein. Otherwise, the drugs may even target different proteins with similar structural features. Designing drugs that successfully target mutant proteins selectively represents a major challenge. Decades of cancer research have led to an abundance of potential therapeutic targets, often touted to be "master regulators". For many of these proteins, there are no FDA-approved drugs available; for others, off-target effects result in dose-limiting toxicity. Cancer-related proteins are an excellent medium to carry the story of mutant-specific targeting, as the disease is both initiated and sustained by mutant proteins; furthermore, current chemotherapies generally fail at adequate selective distinction. This review discusses some of the challenges associated with selective targeting from a structural biology perspective, as well as some of the developments in algorithm approach and computational workflow that can be applied to address those issues. One of the most widely researched proteins in cancer biology is p53, a tumor suppressor. Here, p53 is discussed as a specific example of a challenging target, with contemporary drugs and methodologies used as examples of burgeoning successes. The oncogene KRAS, which has been described as "undruggable", is another extensively investigated protein in cancer biology. This review also examines KRAS to exemplify progress made towards selective targeting of diseasecausing mutant proteins. Finally, possible future directions relevant to the topic are discussed.
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Affiliation(s)
- Mathew A Coban
- Department of Cancer Biology, Mayo Clinic, Jacksonville, FL, 32224, United States
| | - Sarah Fraga
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, 32224, United States
| | - Thomas R Caulfield
- Department of Cancer Biology, Mayo Clinic, Jacksonville, FL, 32224, United States
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17
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Neale C, García AE. The Plasma Membrane as a Competitive Inhibitor and Positive Allosteric Modulator of KRas4B Signaling. Biophys J 2020; 118:1129-1141. [PMID: 32027820 DOI: 10.1016/j.bpj.2019.12.039] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 12/04/2019] [Accepted: 12/18/2019] [Indexed: 12/31/2022] Open
Abstract
Mutant Ras proteins are important drivers of human cancers, yet no approved drugs act directly on this difficult target. Over the last decade, the idea has emerged that oncogenic signaling can be diminished by molecules that drive Ras into orientations in which effector-binding interfaces are occluded by the cell membrane. To support this approach to drug discovery, we characterize the orientational preferences of membrane-bound K-Ras4B in 1.45-ms aggregate time of atomistic molecular dynamics simulations. Individual simulations probe active or inactive states of Ras on membranes with or without anionic lipids. We find that the membrane orientation of Ras is relatively insensitive to its bound guanine nucleotide and activation state but depends strongly on interactions with anionic phosphatidylserine lipids. These lipids slow Ras' translational and orientational diffusion and promote a discrete population in which small changes in orientation control Ras' competence to bind multiple regulator and effector proteins. Our results suggest that compound-directed conversion of constitutively active mutant Ras into functionally inactive forms may be accessible via subtle perturbations of Ras' orientational preferences at the membrane surface.
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Affiliation(s)
- Chris Neale
- Theoretical Biology and Biophysics, Los Alamos National Laboratory, Los Alamos, New Mexico
| | - Angel E García
- Center for Nonlinear Studies, Los Alamos National Laboratory, Los Alamos, New Mexico.
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18
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Khaled M, Gorfe A, Sayyed-Ahmad A. Conformational and Dynamical Effects of Tyr32 Phosphorylation in K-Ras: Molecular Dynamics Simulation and Markov State Models Analysis. J Phys Chem B 2019; 123:7667-7675. [PMID: 31419909 PMCID: PMC7020251 DOI: 10.1021/acs.jpcb.9b05768] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Phosphorylation of tyrosine 32 in K-Ras has been shown to influence function by disrupting the GTPase cycle. To shed light on the underlying mechanism and atomic basis of this process, we carried out a comparative investigation of the oncogenic G12D K-Ras mutant and its phosphorylated variant (pTyr32) using all-atom molecular dynamics simulations and Markov state models. We show that, despite sharing a number of common features, G12D and pTyr32-G12D K-Ras exhibit some distinct conformational states and fluctuations. In addition to notable differences in conformation and dynamics of residues surrounding the GTP binding site, nonlocal changes were observed at a number of loops. Switch I is more flexible in pTyr32-G12D K-Ras while switch II is more flexible in G12D K-Ras. We also used time-lagged independent component analysis and k-means clustering to identify five metastable states for each system. We utilized transition path theory to calculate the transition probabilities for each state to build a Markov state model for each system. These models and other close inspections suggest that the phosphorylation of Tyr32 strongly affects protein dynamics and the active site conformation, especially with regards to the canonical switch conformations and dynamics.
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Affiliation(s)
- Mohammed Khaled
- Department of Physics, Birzeit University, PO Box 14, Birzeit, Palestine
| | - Alemayehu Gorfe
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston, 6431 Fannin Street, Houston, Texas 77030, United States
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19
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Munte CE, Karl M, Kauter W, Eberlein L, Pham TV, Erlach MB, Kast SM, Kremer W, Kalbitzer HR. High pressure response of 1H NMR chemical shifts of purine nucleotides. Biophys Chem 2019; 254:106261. [PMID: 31522070 DOI: 10.1016/j.bpc.2019.106261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2019] [Revised: 09/01/2019] [Accepted: 09/01/2019] [Indexed: 11/25/2022]
Abstract
The study of the pressure response by NMR spectroscopy provides information on the thermodynamics of conformational equilibria in proteins and nucleic acids. For obtaining a database for expected pressure effects on free nucleotides and nucleotides bound in macromolecular complexes, the pressure response of 1H chemical shifts and J-coupling constants of the purine 5'-ribonucleotides AMP, ADP, ATP, GMP, GDP, and GTP were studied in the absence and presence of Mg2+-ions. Experiments are supported by quantum-chemical calculations of populations and chemical shift differences in order to corroborate structural interpretations and to estimate missing data for AMP. The preference of the ribose S puckering obtained from the analysis of the experimental J-couplings is also confirmed by the calculations. In addition, the pressure response of the non-hydrolysable GTP analogues GppNHp, GppCH2p, and GTPγS was examined within a pressure range up to 200 MPa. As observed earlier for 31P NMR chemical shifts of these nucleotides the pressure dependence of chemical shifts is clearly non-linear in most cases. In di- and tri-phospho nucleosides, the resonances of the two protons bound to the ribose 5' carbon are non-equivalent and can be observed separately. The gg-rotamer at C4'- C5' bond is strongly preferred and the downfield shifted resonance can be assigned to the H5″ proton in the nucleotides. In contrast, in adenosine itself the frequencies of the two resonances are interchanged.
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Affiliation(s)
- Claudia E Munte
- University of Regensburg, Institute of Biophysics and Physical Biochemistry, Center of Magnetic Resonance in Chemistry and Biomedicine, Universitätsstraße 31, 93053 Regensburg, Germany
| | - Matthias Karl
- University of Regensburg, Institute of Biophysics and Physical Biochemistry, Center of Magnetic Resonance in Chemistry and Biomedicine, Universitätsstraße 31, 93053 Regensburg, Germany
| | - Waldemar Kauter
- University of Regensburg, Institute of Biophysics and Physical Biochemistry, Center of Magnetic Resonance in Chemistry and Biomedicine, Universitätsstraße 31, 93053 Regensburg, Germany
| | - Lukas Eberlein
- TU Dortmund University, Physical Chemistry III, Otto-Hahn-Straße 4a, 44227 Dortmund, Germany
| | - Thuy-Vy Pham
- University of Regensburg, Institute of Biophysics and Physical Biochemistry, Center of Magnetic Resonance in Chemistry and Biomedicine, Universitätsstraße 31, 93053 Regensburg, Germany
| | - Markus Beck Erlach
- University of Regensburg, Institute of Biophysics and Physical Biochemistry, Center of Magnetic Resonance in Chemistry and Biomedicine, Universitätsstraße 31, 93053 Regensburg, Germany
| | - Stefan M Kast
- TU Dortmund University, Physical Chemistry III, Otto-Hahn-Straße 4a, 44227 Dortmund, Germany
| | - Werner Kremer
- University of Regensburg, Institute of Biophysics and Physical Biochemistry, Center of Magnetic Resonance in Chemistry and Biomedicine, Universitätsstraße 31, 93053 Regensburg, Germany
| | - Hans Robert Kalbitzer
- University of Regensburg, Institute of Biophysics and Physical Biochemistry, Center of Magnetic Resonance in Chemistry and Biomedicine, Universitätsstraße 31, 93053 Regensburg, Germany.
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20
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Feng H, Zhang Y, Bos PH, Chambers JM, Dupont MM, Stockwell BR. K-Ras G12D Has a Potential Allosteric Small Molecule Binding Site. Biochemistry 2019; 58:2542-2554. [PMID: 31042025 DOI: 10.1021/acs.biochem.8b01300] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
KRAS is the most commonly mutated oncogene in human cancer, with particularly high mutation frequencies in pancreatic cancers, colorectal cancers, and lung cancers [Ostrem, J. M., and Shokat, K. M. (2016) Nat. Rev. Drug Discovery 15, 771-785]. The high prevalence of KRAS mutations and its essential role in many cancers make it a potentially attractive drug target; however, it has been difficult to create small molecule inhibitors of mutant K-Ras proteins. Here, we identified a putative small molecule binding site on K-RasG12D using computational analyses of the protein structure and then used a combination of computational and biochemical approaches to discover small molecules that may bind to this pocket, which we have termed the P110 site, due to its adjacency to proline 110. We confirmed that one compound, named K-Ras allosteric ligand KAL-21404358, bound to K-RasG12D, as measured by microscale thermophoresis, a thermal shift assay, and nuclear magnetic resonance spectroscopy. KAL-21404358 did not bind to four mutants in the P110 site, supporting our hypothesis that KAL-21404358 binds to the P110 site of K-RasG12D. This compound impaired the interaction of K-RasG12D with B-Raf and disrupted the RAF-MEK-ERK and PI3K-AKT signaling pathways. We synthesized additional compounds, based on the KAL-21404358 scaffold with more potent binding and greater aqueous solubility. In summary, these findings suggest that the P110 site is a potential site for binding of small molecule allosteric inhibitors of K-RasG12D.
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21
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Winter R. Interrogating the Structural Dynamics and Energetics of Biomolecular Systems with Pressure Modulation. Annu Rev Biophys 2019; 48:441-463. [DOI: 10.1146/annurev-biophys-052118-115601] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
High hydrostatic pressure affects the structure, dynamics, and stability of biomolecular systems and is a key parameter in the context of the exploration of the origin and the physical limits of life. This review lays out the conceptual framework for exploring the conformational fluctuations, dynamical properties, and activity of biomolecular systems using pressure perturbation. Complementary pressure-jump relaxation studies are useful tools to study the kinetics and mechanisms of biomolecular phase transitions and structural transformations, such as membrane fusion or protein and nucleic acid folding. Finally, the advantages of using pressure to explore biomolecular assemblies and modulate enzymatic reactions are discussed.
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Affiliation(s)
- Roland Winter
- Faculty of Chemistry and Chemical Biology, Biophysical Chemistry, TU Dortmund University, D-44227 Dortmund, Germany
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22
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O'Bryan JP. Pharmacological targeting of RAS: Recent success with direct inhibitors. Pharmacol Res 2018; 139:503-511. [PMID: 30366101 DOI: 10.1016/j.phrs.2018.10.021] [Citation(s) in RCA: 98] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Revised: 10/19/2018] [Accepted: 10/21/2018] [Indexed: 02/06/2023]
Abstract
RAS has long been viewed as undruggable due to its lack of deep pockets for binding of small molecule inhibitors. However, recent successes in the development of direct RAS inhibitors suggest that the goal of pharmacological inhibition of RAS in patients may soon be realized. This review will discuss the role of RAS in cancer, the approaches used to develop direct RAS inhibitors, and highlight recent successes in the development of novel RAS inhibitory compounds that target different aspects of RAS biochemistry. In particular, this review will discuss the different properties of RAS that have been targeted by various inhibitors including membrane localization, the different activation states of RAS, effector binding, and nucleotide exchange. In addition, this review will highlight the recent success with mutation-specific inhibitors that exploit the unique biochemistry of the RAS(G12C) mutant. Although this mutation in KRAS accounts for 11% of all KRAS mutations in cancer, it is the most prominent KRAS mutant in lung cancer suggesting that G12C-specific inhibitors may provide a new approach for treating the subset of lung cancer patients harboring this mutant allele. Finally, this review will discuss the involvement of dimerization in RAS function and highlight new approaches to inhibit RAS by specifically interfering with RAS:RAS interaction.
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Affiliation(s)
- John P O'Bryan
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Hollings Cancer Center, Medical University of South Carolina, Charleston, SC, 29425, United States; Ralph H. Johnson VA Medical Center, Charleston, SC, 29401, United States.
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23
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Li Y, Zhang Y, Großerüschkamp F, Stephan S, Cui Q, Kötting C, Xia F, Gerwert K. Specific Substates of Ras To Interact with GAPs and Effectors: Revealed by Theoretical Simulations and FTIR Experiments. J Phys Chem Lett 2018; 9:1312-1317. [PMID: 29488771 PMCID: PMC6692134 DOI: 10.1021/acs.jpclett.8b00342] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The oncogenic Ras protein adopts various specific conformational states to execute its function in signal transduction. The large number of Ras structures obtained from X-ray and NMR experiments illustrates the diverse conformations that Ras adopts. It is difficult, however, to connect specific structural features with Ras functions. We report the free-energy landscape of Ras·GTP based on extensive explicit solvent simulations. The free-energy map clearly shows that the functional state 2 of Ras·GTP in fact has two distinct substates, denoted here as "Tyr32in" and "Tyr32out". Unbiased MD simulations show that the two substrates interconvert on the submicrosecond scale in solution, pointing to a novel mechanism for Ras·GTP to selectively interact with GAPs and effectors. This proposal is further supported by time-resolved FTIR experiments, which demonstrate that Tyr32 destabilizes the Ras·GAP complex and facilitates an efficient termination of Ras signaling.
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Affiliation(s)
- Yang Li
- School of Chemistry and Molecular Engineering , East China Normal University , Shanghai 200062 , China
- School of Information Science and Engineering , Shandong Agricultural University , Taian 271018 , China
| | - Yuwei Zhang
- School of Chemistry and Molecular Engineering , East China Normal University , Shanghai 200062 , China
| | | | - Sara Stephan
- Department of Biophysics , Ruhr-University Bochum , ND 04 North , 44780 Bochum , Germany
| | - Qiang Cui
- Department of Chemistry and Theoretical Chemistry Institute , University of Wisconsin , 1101 University Avenue , Madison , Wisconsin 53706 , United States
| | - Carsten Kötting
- Department of Biophysics , Ruhr-University Bochum , ND 04 North , 44780 Bochum , Germany
| | - Fei Xia
- School of Chemistry and Molecular Engineering , East China Normal University , Shanghai 200062 , China
- NYU-ECNU Center for Computational Chemistry at NYU Shanghai , Shanghai 200062 , China
| | - Klaus Gerwert
- Department of Biophysics , Ruhr-University Bochum , ND 04 North , 44780 Bochum , Germany
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24
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Mann D, Güldenhaupt J, Schartner J, Gerwert K, Kötting C. The protonation states of GTP and GppNHp in Ras proteins. J Biol Chem 2018; 293:3871-3879. [PMID: 29382720 DOI: 10.1074/jbc.ra117.001110] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2017] [Revised: 01/29/2018] [Indexed: 01/09/2023] Open
Abstract
The small GTPase Ras transmits signals in a variety of cellular signaling pathways, most prominently in cell proliferation. GTP hydrolysis in the active center of Ras acts as a prototype for many GTPases and is the key to the understanding of several diseases, including cancer. Therefore, Ras has been the focus of intense research over the last decades. A recent neutron diffraction crystal structure of Ras indicated a protonated γ-guanylyl imidodiphosphate (γ-GppNHp) group, which has put the protonation state of GTP in question. A possible protonation of GTP was not considered in previously published mechanistic studies. To determine the detailed prehydrolysis state of Ras, we calculated infrared and NMR spectra from quantum mechanics/molecular mechanics (QM/MM) simulations and compared them with those from previous studies. Furthermore, we measured infrared spectra of GTP and several GTP analogs bound to lipidated Ras on a membrane system under near-native conditions. Our findings unify results from previous studies and indicate a structural model confirming the hypothesis that γ-GTP is fully deprotonated in the prehydrolysis state of Ras.
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Affiliation(s)
- Daniel Mann
- From the Department of Biophysics, Ruhr University Bochum, 44780 Bochum, Germany and
| | - Jörn Güldenhaupt
- From the Department of Biophysics, Ruhr University Bochum, 44780 Bochum, Germany and
| | - Jonas Schartner
- From the Department of Biophysics, Ruhr University Bochum, 44780 Bochum, Germany and
| | - Klaus Gerwert
- From the Department of Biophysics, Ruhr University Bochum, 44780 Bochum, Germany and .,Max-Planck-Gesellschaft-Chinese Academy of Sciences (MPG-CAS) Partner Institute for Computational Biology (PICB), Shanghai 200031, China
| | - Carsten Kötting
- From the Department of Biophysics, Ruhr University Bochum, 44780 Bochum, Germany and
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25
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De Cicco M, Kiss L, Dames SA. NMR analysis of the backbone dynamics of the small GTPase Rheb and its interaction with the regulatory protein FKBP38. FEBS Lett 2017; 592:130-146. [PMID: 29194576 DOI: 10.1002/1873-3468.12925] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Revised: 10/06/2017] [Accepted: 11/17/2017] [Indexed: 12/19/2022]
Abstract
Ras homolog enriched in brain (Rheb) is a small GTPase that regulates mammalian/mechanistic target of rapamycin complex 1 (mTORC1) and, thereby, cell growth and metabolism. Here we show that cycling between the inactive GDP- and the active GTP-bound state modulates the backbone dynamics of a C-terminal truncated form, RhebΔCT, which is suggested to influence its interactions. We further investigated the interactions between RhebΔCT and the proposed Rheb-binding domain of the regulatory protein FKBP38. The observed weak interactions with the GTP-analogue- (GppNHp-) but not the GDP-bound state, appear to accelerate the GDP to GTP exchange, but only very weakly compared to a genuine GEF. Thus, FKBP38 is most likely not a GEF but a Rheb effector that may function in membrane targeting of Rheb.
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Affiliation(s)
- Maristella De Cicco
- Technische Universität München, Department of Chemistry, Biomolecular NMR Spectroscopy, Garching, Germany
| | - Leo Kiss
- Technische Universität München, Department of Chemistry, Biomolecular NMR Spectroscopy, Garching, Germany
| | - Sonja A Dames
- Technische Universität München, Department of Chemistry, Biomolecular NMR Spectroscopy, Garching, Germany.,Institute of Structural Biology, Helmholtz Zentrum München, Neuherberg, Germany
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26
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Sayyed-Ahmad A, Prakash P, Gorfe AA. Distinct dynamics and interaction patterns in H- and K-Ras oncogenic P-loop mutants. Proteins 2017; 85:1618-1632. [PMID: 28498561 DOI: 10.1002/prot.25317] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2017] [Revised: 04/27/2017] [Accepted: 05/05/2017] [Indexed: 12/31/2022]
Abstract
Despite years of study, the structural or dynamical basis for the differential reactivity and oncogenicity of Ras isoforms and mutants remains unclear. In this study, we investigated the effects of amino acid variations on the structure and dynamics of wild type and oncogenic mutants G12D, G12V, and G13D of H- and K-Ras proteins. Based on data from µs-scale molecular dynamics simulations, we show that the overall structure of the proteins remains similar but there are important differences in dynamics and interaction networks. We identified differences in residue interaction patterns around the canonical switch and distal loop regions, and persistent sodium ion binding near the GTP particularly in the G13D mutants. Our results also suggest that different Ras variants have distinct local structural features and interactions with the GTP, variations that have the potential to affect GTP release and hydrolysis. Furthermore, we found that H-Ras proteins and particularly the G12V and G13D variants are significantly more flexible than their K-Ras counterparts. Finally, while most of the simulated proteins sampled the effector-interacting state 2 conformational state, G12V and G13D H-Ras adopted an open switch state 1 conformation that is defective in effector interaction. These differences have implications for Ras GTPase activity, effector or exchange factor binding, dimerization and membrane interaction. Proteins 2017; 85:1618-1632. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Abdallah Sayyed-Ahmad
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston, Houston, Texas, 77030
| | - Priyanka Prakash
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston, Houston, Texas, 77030
| | - Alemayehu A Gorfe
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston, Houston, Texas, 77030
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27
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Ozgur B, Ozdemir ES, Gursoy A, Keskin O. Relation between Protein Intrinsic Normal Mode Weights and Pre-Existing Conformer Populations. J Phys Chem B 2017; 121:3686-3700. [DOI: 10.1021/acs.jpcb.6b10401] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Beytullah Ozgur
- Center for Computational Biology and Bioinformatics, ‡Chemical and Biological
Engineering, and §Computer Engineering,
College of Engineering, Koc University, 34450 Istanbul, Turkey
| | - E. Sila Ozdemir
- Center for Computational Biology and Bioinformatics, ‡Chemical and Biological
Engineering, and §Computer Engineering,
College of Engineering, Koc University, 34450 Istanbul, Turkey
| | - Attila Gursoy
- Center for Computational Biology and Bioinformatics, ‡Chemical and Biological
Engineering, and §Computer Engineering,
College of Engineering, Koc University, 34450 Istanbul, Turkey
| | - Ozlem Keskin
- Center for Computational Biology and Bioinformatics, ‡Chemical and Biological
Engineering, and §Computer Engineering,
College of Engineering, Koc University, 34450 Istanbul, Turkey
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28
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Spoerner M, Karl M, Lopes P, Hoering M, Loeffel K, Nuehs A, Adelsberger J, Kremer W, Kalbitzer HR. High pressure 31P NMR spectroscopy on guanine nucleotides. JOURNAL OF BIOMOLECULAR NMR 2017; 67:1-13. [PMID: 28012125 DOI: 10.1007/s10858-016-0079-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Accepted: 12/05/2016] [Indexed: 06/06/2023]
Abstract
The 31P NMR pressure response of guanine nucleotides bound to proteins has been studied in the past for characterizing the pressure perturbation of conformational equilibria. The pressure response of the 31P NMR chemical shifts of the phosphate groups of GMP, GDP, and GTP as well as the commonly used GTP analogs GppNHp, GppCH2p and GTPγS was measured in the absence and presence of Mg2+-ions within a pressure range up to 200 MPa. The pressure dependence of chemical shifts is clearly non-linear. For all nucleotides a negative first order pressure coefficient B 1 was determined indicating an upfield shift of the resonances with pressure. With exception of the α-phosphate group of Mg2+·GMP and Mg2+·GppNHp the second order pressure coefficients are positive. To describe the data of Mg2+·GppCH2p and GTPγS a Taylor expansion of 3rd order is required. For distinguishing pH effects from pressure effects a complete pH titration set is presented for GMP, as well as GDP and GTP in absence and presence of Mg2+ ions using indirect referencing to DSS under identical experimental conditions. By a comparison between high pressure 31P NMR data on free Mg2+-GDP and Mg2+-GDP in complex with the proto-oncogene Ras we demonstrate that pressure induced changes in chemical shift are clearly different between both forms.
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Affiliation(s)
- Michael Spoerner
- Centre of Magnetic Resonance in Chemistry and Biomedicine, Institute of Biophysics and Physical Biochemistry, University of Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany
| | - Matthias Karl
- Centre of Magnetic Resonance in Chemistry and Biomedicine, Institute of Biophysics and Physical Biochemistry, University of Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany
| | - Pedro Lopes
- Centre of Magnetic Resonance in Chemistry and Biomedicine, Institute of Biophysics and Physical Biochemistry, University of Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany
| | - Marcus Hoering
- Centre of Magnetic Resonance in Chemistry and Biomedicine, Institute of Biophysics and Physical Biochemistry, University of Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany
| | - Karoline Loeffel
- Centre of Magnetic Resonance in Chemistry and Biomedicine, Institute of Biophysics and Physical Biochemistry, University of Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany
| | - Andrea Nuehs
- Centre of Magnetic Resonance in Chemistry and Biomedicine, Institute of Biophysics and Physical Biochemistry, University of Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany
| | - Joseph Adelsberger
- Centre of Magnetic Resonance in Chemistry and Biomedicine, Institute of Biophysics and Physical Biochemistry, University of Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany
| | - Werner Kremer
- Centre of Magnetic Resonance in Chemistry and Biomedicine, Institute of Biophysics and Physical Biochemistry, University of Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany
| | - Hans Robert Kalbitzer
- Centre of Magnetic Resonance in Chemistry and Biomedicine, Institute of Biophysics and Physical Biochemistry, University of Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany.
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29
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Knyphausen P, Lang F, Baldus L, Extra A, Lammers M. Insights into K-Ras 4B regulation by post-translational lysine acetylation. Biol Chem 2016; 397:1071-85. [DOI: 10.1515/hsz-2016-0118] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Accepted: 05/03/2016] [Indexed: 11/15/2022]
Abstract
Abstract
Ras is a molecular switch cycling between an active, GTP-bound and an inactive, GDP-bound state. Mutations in Ras, mostly affecting the off-switch, are found in many human tumours. Recently, it has been shown that K-Ras 4B is targeted by lysine acetylation at K104. Based on results obtained for an acetylation mimetic Ras mutant (K104Q), it was hypothesised that K104-acetylation might interfere with its oncogenicity by impairing SOS-catalysed guanine-nucleotide exchange. We prepared site-specifically K104-acetylated K-Ras 4B and the corresponding oncogenic mutant protein G12V using the genetic-code expansion concept. We found that SOS-catalysed nucleotide exchange, also of allosterically activated SOS, was neither affected by acetylation of K104 in wildtype K-Ras 4B nor in the G12V mutant, suggesting that glutamine is a poor mimetic for acetylation at this site. In vitro, the lysine-acetyltransferases CBP and p300 were able to acetylate both, wildtype and G12V K-Ras 4B. In addition to K104 we identified further acetylation sites in K-Ras 4B, including K147, within the important G5/SAK-motif. However, the intrinsic and the SOS-catalysed nucleotide exchange was not affected by K147-acetylation of K-Ras 4B. Finally, we show that Sirt2 and HDAC6 do neither deacetylate K-Ras 4B if acetylated at K104 nor if acetylated at K147 in vitro.
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30
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Mishra AK, Lambright DG. Invited review: Small GTPases and their GAPs. Biopolymers 2016; 105:431-48. [PMID: 26972107 PMCID: PMC5439442 DOI: 10.1002/bip.22833] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Revised: 02/16/2016] [Accepted: 03/10/2016] [Indexed: 12/11/2022]
Abstract
Widespread utilization of small GTPases as major regulatory hubs in many different biological systems derives from a conserved conformational switch mechanism that facilitates cycling between GTP-bound active and GDP-bound inactive states under control of guanine nucleotide exchange factors (GEFs) and GTPase activating proteins (GAPs), which accelerate slow intrinsic rates of activation by nucleotide exchange and deactivation by GTP hydrolysis, respectively. Here we review developments leading to current understanding of intrinsic and GAP catalyzed GTP hydrolytic reactions in small GTPases from structural, molecular and chemical mechanistic perspectives. Despite the apparent simplicity of the GTPase cycle, the structural bases underlying the hallmark hydrolytic reaction and catalytic acceleration by GAPs are considerably more diverse than originally anticipated. Even the most fundamental aspects of the reaction mechanism have been challenging to decipher. Through a combination of experimental and in silico approaches, the outlines of a consensus view have begun to emerge for the best studied paradigms. Nevertheless, recent observations indicate that there is still much to be learned. © 2016 Wiley Periodicals, Inc. Biopolymers 105: 431-448, 2016.
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Affiliation(s)
- Ashwini K Mishra
- Program in Molecular Medicine and Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA, 01605
| | - David G Lambright
- Program in Molecular Medicine and Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA, 01605
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31
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Lu S, Jang H, Muratcioglu S, Gursoy A, Keskin O, Nussinov R, Zhang J. Ras Conformational Ensembles, Allostery, and Signaling. Chem Rev 2016; 116:6607-65. [PMID: 26815308 DOI: 10.1021/acs.chemrev.5b00542] [Citation(s) in RCA: 259] [Impact Index Per Article: 32.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Ras proteins are classical members of small GTPases that function as molecular switches by alternating between inactive GDP-bound and active GTP-bound states. Ras activation is regulated by guanine nucleotide exchange factors that catalyze the exchange of GDP by GTP, and inactivation is terminated by GTPase-activating proteins that accelerate the intrinsic GTP hydrolysis rate by orders of magnitude. In this review, we focus on data that have accumulated over the past few years pertaining to the conformational ensembles and the allosteric regulation of Ras proteins and their interpretation from our conformational landscape standpoint. The Ras ensemble embodies all states, including the ligand-bound conformations, the activated (or inactivated) allosteric modulated states, post-translationally modified states, mutational states, transition states, and nonfunctional states serving as a reservoir for emerging functions. The ensemble is shifted by distinct mutational events, cofactors, post-translational modifications, and different membrane compositions. A better understanding of Ras biology can contribute to therapeutic strategies.
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Affiliation(s)
- Shaoyong Lu
- Department of Pathophysiology, Shanghai Universities E-Institute for Chemical Biology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University, School of Medicine , Shanghai, 200025, China.,Cancer and Inflammation Program, Leidos Biomedical Research, Inc., Frederick National Laboratory, National Cancer Institute , Frederick, Maryland 21702, United States
| | - Hyunbum Jang
- Cancer and Inflammation Program, Leidos Biomedical Research, Inc., Frederick National Laboratory, National Cancer Institute , Frederick, Maryland 21702, United States
| | | | | | | | - Ruth Nussinov
- Cancer and Inflammation Program, Leidos Biomedical Research, Inc., Frederick National Laboratory, National Cancer Institute , Frederick, Maryland 21702, United States.,Department of Human Genetics and Molecular Medicine, Sackler School of Medicine, Sackler Institute of Molecular Medicine, Tel Aviv University , Tel Aviv 69978, Israel
| | - Jian Zhang
- Department of Pathophysiology, Shanghai Universities E-Institute for Chemical Biology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University, School of Medicine , Shanghai, 200025, China
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32
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Knihtila R, Holzapfel G, Weiss K, Meilleur F, Mattos C. Neutron Crystal Structure of RAS GTPase Puts in Question the Protonation State of the GTP γ-Phosphate. J Biol Chem 2015; 290:31025-36. [PMID: 26515069 DOI: 10.1074/jbc.m115.679860] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2015] [Indexed: 11/06/2022] Open
Abstract
RAS GTPase is a prototype for nucleotide-binding proteins that function by cycling between GTP and GDP, with hydrogen atoms playing an important role in the GTP hydrolysis mechanism. It is one of the most well studied proteins in the superfamily of small GTPases, which has representatives in a wide range of cellular functions. These proteins share a GTP-binding pocket with highly conserved motifs that promote hydrolysis to GDP. The neutron crystal structure of RAS presented here strongly supports a protonated γ-phosphate at physiological pH. This counters the notion that the phosphate groups of GTP are fully deprotonated at the start of the hydrolysis reaction, which has colored the interpretation of experimental and computational data in studies of the hydrolysis mechanism. The neutron crystal structure presented here puts in question our understanding of the pre-catalytic state associated with the hydrolysis reaction central to the function of RAS and other GTPases.
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Affiliation(s)
- Ryan Knihtila
- From the Department of Chemistry and Chemical Biology, Northeastern University, Boston, Massachusetts 02115
| | - Genevieve Holzapfel
- the Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, North Carolina 27695, and
| | - Kevin Weiss
- the Biology and Soft Matter Division, Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831
| | - Flora Meilleur
- the Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, North Carolina 27695, and the Biology and Soft Matter Division, Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831
| | - Carla Mattos
- From the Department of Chemistry and Chemical Biology, Northeastern University, Boston, Massachusetts 02115, the Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, North Carolina 27695, and
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33
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Luong TQ, Kapoor S, Winter R. Pressure-A Gateway to Fundamental Insights into Protein Solvation, Dynamics, and Function. Chemphyschem 2015; 16:3555-71. [DOI: 10.1002/cphc.201500669] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Indexed: 01/11/2023]
Affiliation(s)
- Trung Quan Luong
- Department of Chemistry and Chemical Biology, Physical Chemistry; TU Dortmund University, Dortmund; Otto-Hahn-Str. 6 d-44221 Dortmund Germany
| | - Shobhna Kapoor
- Department of Chemistry and Chemical Biology, Physical Chemistry; TU Dortmund University, Dortmund; Otto-Hahn-Str. 6 d-44221 Dortmund Germany
| | - Roland Winter
- Department of Chemistry and Chemical Biology, Physical Chemistry; TU Dortmund University, Dortmund; Otto-Hahn-Str. 6 d-44221 Dortmund Germany
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34
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Cromm PM, Spiegel J, Grossmann TN, Waldmann H. Direkte Modulation von Aktivität und Funktion kleiner GTPasen. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201504357] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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35
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Cromm PM, Spiegel J, Grossmann TN, Waldmann H. Direct Modulation of Small GTPase Activity and Function. Angew Chem Int Ed Engl 2015; 54:13516-37. [DOI: 10.1002/anie.201504357] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Indexed: 12/19/2022]
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36
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Aramini JM, Vorobiev SM, Tuberty LM, Janjua H, Campbell ET, Seetharaman J, Su M, Huang YJ, Acton TB, Xiao R, Tong L, Montelione GT. The RAS-Binding Domain of Human BRAF Protein Serine/Threonine Kinase Exhibits Allosteric Conformational Changes upon Binding HRAS. Structure 2015; 23:1382-1393. [PMID: 26165597 DOI: 10.1016/j.str.2015.06.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2015] [Revised: 05/27/2015] [Accepted: 06/04/2015] [Indexed: 02/07/2023]
Abstract
RAS binding is a critical step in the activation of BRAF protein serine/threonine kinase and stimulation of the mitogen-activated protein kinase signaling pathway. Mutations in both RAS and BRAF are associated with many human cancers. Here, we report the solution nuclear magnetic resonance (NMR) and X-ray crystal structures of the RAS-binding domain (RBD) from human BRAF. We further studied the complex between BRAF RBD and the GppNHp bound form of HRAS in solution. Backbone, side-chain, and (19)F NMR chemical shift perturbations reveal unexpected changes distal to the RAS-binding face that extend through the core of the RBD structure. Moreover, backbone amide hydrogen/deuterium exchange NMR data demonstrate conformational ensemble changes in the RBD core structure upon complex formation. These changes in BRAF RBD reveal a basis for allosteric regulation of BRAF structure and function, and suggest a mechanism by which RAS binding can signal the drastic domain rearrangements required for activation of BRAF kinase.
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Affiliation(s)
- James M Aramini
- Center for Advanced Biotechnology and Medicine, Department of Molecular Biology and Biochemistry, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA; Northeast Structural Genomics Consortium, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA.
| | - Sergey M Vorobiev
- Department of Biological Sciences, Northeast Structural Genomics Consortium, Columbia University, New York, NY 10027, USA
| | - Lynda M Tuberty
- Center for Advanced Biotechnology and Medicine, Department of Molecular Biology and Biochemistry, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
| | - Haleema Janjua
- Center for Advanced Biotechnology and Medicine, Department of Molecular Biology and Biochemistry, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA; Northeast Structural Genomics Consortium, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
| | - Elliot T Campbell
- Center for Advanced Biotechnology and Medicine, Department of Molecular Biology and Biochemistry, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
| | - Jayaraman Seetharaman
- Department of Biological Sciences, Northeast Structural Genomics Consortium, Columbia University, New York, NY 10027, USA
| | - Min Su
- Department of Biological Sciences, Northeast Structural Genomics Consortium, Columbia University, New York, NY 10027, USA
| | - Yuanpeng J Huang
- Center for Advanced Biotechnology and Medicine, Department of Molecular Biology and Biochemistry, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA; Northeast Structural Genomics Consortium, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
| | - Thomas B Acton
- Center for Advanced Biotechnology and Medicine, Department of Molecular Biology and Biochemistry, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA; Northeast Structural Genomics Consortium, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
| | - Rong Xiao
- Center for Advanced Biotechnology and Medicine, Department of Molecular Biology and Biochemistry, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA; Northeast Structural Genomics Consortium, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
| | - Liang Tong
- Department of Biological Sciences, Northeast Structural Genomics Consortium, Columbia University, New York, NY 10027, USA
| | - Gaetano T Montelione
- Center for Advanced Biotechnology and Medicine, Department of Molecular Biology and Biochemistry, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA; Northeast Structural Genomics Consortium, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA; Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA.
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37
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Abstract
Proteins usually exist in multiple conformational states in solution. High pressure NMR spectroscopy is a well-suited method to identify these states. In addition, these states can be characterized by their thermodynamic parameters, the free enthalpies at ambient pressure, the partial molar volumes, and the partial molar compressibility that can be obtained from the analysis of the high pressure NMR data. Two main types of states of proteins exist, functional states and folding states. There is a strong link between these two types, the functional states represent essential folding states (intermediates), other folding states may have no functional meaning (optional folding states). In this chapter, this concept is tested on the Ras protein, an important proto-oncogen in humans where all substates required by theory can be identified experimentally by high pressure NMR spectroscopy. Finally, we show how these data can be used to develop allosteric inhibitors of proteins.
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38
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Rosnizeck IC, Filchtinski D, Lopes RP, Kieninger B, Herrmann C, Kalbitzer HR, Spoerner M. Elucidating the mode of action of a typical Ras state 1(T) inhibitor. Biochemistry 2014; 53:3867-78. [PMID: 24866928 DOI: 10.1021/bi401689w] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The small GTPase Ras is an essential component of signal transduction pathways within the cell, controlling proliferation, differentiation, and apoptosis. Only in the GTP-bound form does Ras interact strongly with effector molecules such as Raf-kinase, thus acting as a molecular switch. In the GTP-bound form, Ras exists in a dynamic equilibrium between at least two distinct conformational states, 1(T) and 2(T), offering different functional properties of the protein. Zn2+-cyclen is a typical state 1(T) inhibitor; i.e., it interacts selectively with Ras in conformational state 1(T), a weak effector binding state. Here we report that active K-Ras4B, which is prominently found to be mutated in human tumors, exhibits a dynamic equilibrium like H-Ras, which can be modulated by Zn2+-cyclen. The titration experiments of Ras with Zn2+-cyclen indicate a cooperatively coupled binding of the ligands to the two interaction sites on Ras that could be identified for H-Ras previously. Our data further indicate that as in state 2(T) where induced fit produces the substate 2(T)* after effector binding, a corresponding substate 1(T)* can be detected at the state 1(T) mutant Ras(T35A). The interaction of Zn2+-cyclen with Ras not only shifts the equilibrium toward the weak effector binding state 1(T) but also perturbs the formation of substate 1(T)*, thus enhancing the inhibitory effect. Although Zn2+-cyclen shows an affinity for Ras in only the millimolar range, its potency of inhibition corresponds to a competitive state 2 inhibitor with micromolar binding affinity. Thus, the results demonstrate the mode of action and potency of this class of allosteric Ras inhibitors.
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39
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Lin J, Gerwert K, Kötting C. A modified infrared spectrometer with high time resolution and its application for investigating fast conformational changes of the GTPase Ras. APPLIED SPECTROSCOPY 2014; 68:531-535. [PMID: 25014595 DOI: 10.1366/13-07320] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Time-resolved infrared spectroscopy is a valuable tool for the investigation of proteins and protein interactions. The investigation of many biological processes is possible by means of caged compounds, which set free biologically active substances upon light activation. Some caged compounds could provide sub-nanosecond time resolution, e.g., para-hydroxyphenacyl-guanosine 5'-triphosphate (GTP) forms GTP in picoseconds. However, the time resolution in single shot experiments with rapid-scan Fourier transform infrared (FT-IR) spectrometers is limited to about 10 ms. Here we use an infrared diode laser instead of the conventional globar and achieve a time resolution of 100 ns. This allows for the time-resolved measurement of the fast Ras(off) to Ras(on) conformational change at room temperature. We quantified the activation parameters for this reaction and found that the free energy of activation for this reaction is mainly enthalpic. Investigation of the same reaction in the presence of the Ras binding domain of the effector Raf (RafRBD) reveals a four orders of magnitude faster reaction, indicating that Ras·RafRBD complex formation directly induces the conformational change. Recent developments of broadly tunable quantum cascade lasers will further improve time resolution and usability of the setup. The reported 100 ns time resolution is the best achieved for a non-repetitive experiment so far.
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Affiliation(s)
- Jie Lin
- Department of Biophysics, Ruhr-University Bochum, Universitäetsstr. 150, Bochum 44801, Germany
| | - Klaus Gerwert
- Department of Biophysics, Ruhr-University Bochum, Universitäetsstr. 150, Bochum 44801, Germany
| | - Carsten Kötting
- Department of Biophysics, Ruhr-University Bochum, Universitäetsstr. 150, Bochum 44801, Germany
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Kalbitzer HR, Rosnizeck IC, Munte CE, Narayanan SP, Kropf V, Spoerner M. Intrinsische allosterische Hemmung von Signalproteinen durch Stabilisierung gering besetzter, durch Hochdruck-NMR-Spektroskopie nachweisbarer Interaktionszustände. Angew Chem Int Ed Engl 2013. [DOI: 10.1002/ange.201305741] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Kalbitzer HR, Rosnizeck IC, Munte CE, Narayanan SP, Kropf V, Spoerner M. Intrinsic Allosteric Inhibition of Signaling Proteins by Targeting Rare Interaction States Detected by High-Pressure NMR Spectroscopy. Angew Chem Int Ed Engl 2013; 52:14242-6. [DOI: 10.1002/anie.201305741] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2013] [Revised: 08/20/2013] [Indexed: 11/10/2022]
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Long D, Marshall CB, Bouvignies G, Mazhab-Jafari MT, Smith MJ, Ikura M, Kay LE. A Comparative CEST NMR Study of Slow Conformational Dynamics of Small GTPases Complexed with GTP and GTP Analogues. Angew Chem Int Ed Engl 2013. [DOI: 10.1002/ange.201305434] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Long D, Marshall CB, Bouvignies G, Mazhab-Jafari MT, Smith MJ, Ikura M, Kay LE. A comparative CEST NMR study of slow conformational dynamics of small GTPases complexed with GTP and GTP analogues. Angew Chem Int Ed Engl 2013; 52:10771-4. [PMID: 24039022 DOI: 10.1002/anie.201305434] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2013] [Indexed: 01/14/2023]
Affiliation(s)
- Dong Long
- Departments of Molecular Genetics, Biochemistry, and Chemistry, University of Toronto, Toronto, Ontario M5S 1A8 (Canada)
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Khazak V, Eyrisch S, Kato J, Tamanoi F, Golemis EA. A two-hybrid approach to identify inhibitors of the RAS-RAF interaction. Enzymes 2013; 33 Pt A:213-48. [PMID: 25033807 DOI: 10.1016/b978-0-12-416749-0.00010-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
MCP compounds were developed with the idea to inhibit RAS/RAF interaction. They were identified by carrying out high-throughput screens of chemical compounds for their ability to inhibit RAS/RAF interaction in the yeast two-hybrid assay. A number of compounds including MCP1, MCP53, and MCP110 were identified as active compounds. Their inhibition of the RAS signaling was demonstrated by examining RAF and MEK activities, phosphorylation of ERK as well as characterizing their effects on events downstream of RAF. Direct evidence for the inhibition of RAS/RAF interaction was obtained by carrying out co-IP experiments. MCP compounds inhibit proliferation of a wide range of human cancer cell lines. Combination studies with other drugs showed that MCP compounds synergize with MAPK pathway inhibitors as well as with microtubule-targeting chemotherapeutics. In particular, a strong synergy with paclitaxel was observed. Efficacy to inhibit tumor formation was demonstrated using mouse xenograft models. Combination of MCP110 and paclitaxel was particularly effective in inhibiting tumor growth in a mouse xenograft model of colorectal carcinoma.
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Affiliation(s)
- Vladimir Khazak
- Program in Biology, Priaxon Inc., Philadelphia, Pennsylvania, USA.
| | | | - Juran Kato
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, California, USA
| | - Fuyuhiko Tamanoi
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, California, USA
| | - Erica A Golemis
- Program in Biology, Priaxon Inc., Philadelphia, Pennsylvania, USA; Program in Developmental Therapeutics, Fox Chase Cancer Center, Philadelphia, Pennsylvania, USA.
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Prakash P, Gorfe AA. Lessons from computer simulations of Ras proteins in solution and in membrane. Biochim Biophys Acta Gen Subj 2013; 1830:5211-8. [PMID: 23906604 DOI: 10.1016/j.bbagen.2013.07.024] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2013] [Revised: 07/23/2013] [Accepted: 07/24/2013] [Indexed: 12/22/2022]
Abstract
BACKGROUND A great deal has been learned over the last several decades about the function of Ras proteins in solution and membrane environments. While much of this knowledge has been derived from a plethora of experimental techniques, computer simulations have also played a substantial role. SCOPE OF REVIEW Our goal here is to summarize the contribution of molecular simulations to our current understanding of normal and aberrant Ras function. We focus on lessons from molecular dynamics simulations in aqueous and membrane environments. MAJOR CONCLUSIONS The central message is that a close interaction between theory and simulation on the one hand and cell-biological, spectroscopic and other experimental approaches on the other has played, and will likely continue to play, a vital role in Ras research. GENERAL SIGNIFICANCE Atomistic insights emerging from detailed simulations of Ras in solution and in bilayers may be the key to unlock the secret that to date prevented development of selective anti-Ras inhibitors for cancer therapy.
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Affiliation(s)
- Priyanka Prakash
- University of Texas Health Science Center at Houston, Department of Integrative Biology and Pharmacology, 6431 Fannin St., Houston, TX 77030, USA
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Rosnizeck IC, Spoerner M, Harsch T, Kreitner S, Filchtinski D, Herrmann C, Engel D, König B, Kalbitzer HR. Metal-Bis(2-picolyl)amine Complexes as State 1(T) Inhibitors of Activated Ras Protein. Angew Chem Int Ed Engl 2012; 51:10647-51. [DOI: 10.1002/anie.201204148] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2012] [Indexed: 11/10/2022]
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Rosnizeck IC, Spoerner M, Harsch T, Kreitner S, Filchtinski D, Herrmann C, Engel D, König B, Kalbitzer HR. Metall-Bis(2-picolyl)amin-Komplexe als Zustand-1(T)-Inhibitoren für aktiviertes Ras-Protein. Angew Chem Int Ed Engl 2012. [DOI: 10.1002/ange.201204148] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Wittinghofer A, Vetter IR. Structure-function relationships of the G domain, a canonical switch motif. Annu Rev Biochem 2011; 80:943-71. [PMID: 21675921 DOI: 10.1146/annurev-biochem-062708-134043] [Citation(s) in RCA: 330] [Impact Index Per Article: 25.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
GTP-binding (G) proteins constitute a class of P-loop (phosphate-binding loop) proteins that work as molecular switches between the GDP-bound OFF and the GTP-bound ON state. The common principle is the 160-180-residue G domain with an α,β topology that is responsible for nucleotide-dependent conformational changes and drives many biological functions. Although the G domain uses a universally conserved switching mechanism, its structure, function, and GTPase reaction are modified for many different pathways and processes.
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Meierhofer T, Eberhardt M, Spoerner M. Conformational states of ADP ribosylation factor 1 complexed with different guanosine triphosphates as studied by 31P NMR spectroscopy. Biochemistry 2011; 50:6316-27. [PMID: 21702511 DOI: 10.1021/bi101573j] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Guanine nucleotide binding proteins (GNB-proteins) play an essential role in cellular signaling, acting as molecular switches, cycling between the inactive, GDP-bound form and the active, GTP-bound form. It has been shown that conformational equilibria also exist within the active form of GNB-proteins between conformational states with different functional properties. Here we present (31)P NMR data on ADP ribosylation factor 1 (Arf1), a GNB-protein involved in Golgi traffic, promoting the coating of secretory vesicles. To investigate conformational equilibria in active Arf1, the wild type and switch I mutants complexed with GTP and a variety of commonly used GTP analogues, namely, GppCH(2)p, GppNHp, and GTPγS, were analyzed. To gain deeper insight into the conformational state of active Arf1, we titrated with Cu(2+)-cyclen and GdmCl and formed the complex with the Sec7 domain of nucleotide exchange factor ARNO and an effector GAT domain. In contrast to the related proteins Ras, Ral, Cdc42, and Ran, from (31)P NMR spectroscopic view, Arf1 exists predominantly in a single conformation independent of the GTP analogue used. This state seems to correspond to the so-called state 2(T) conformation, according to Ras nomenclature, which is interacting with the effector domain. The exchange of the highly conserved threonine in position 48 with alanine led to a shift of the equilibrium toward a conformational state with typical properties obtained for state 1(T) in Ras, such as interaction with guanine nucleotide exchange factors, a lower affinity for nucleoside triphosphates, and greater sensitivity to chaotropic agents. In active Arf1(wt), the effector interacting conformation is strongly favored. These intrinsic conformational equilibria of active GNB-proteins could be a fine-tuning mechanism of regulation and thereby an interesting target for the modulation of protein activity.
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Affiliation(s)
- Tanja Meierhofer
- University of Regensburg, Institute of Biophysics and Physical Biochemistry, Universitätsstrasse 31, D-93053 Regensburg, Germany
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