1
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Lee SY, Lee KY. Conditional Cooperativity in RAS Assembly Pathways on Nanodiscs and Altered GTPase Cycling. Angew Chem Int Ed Engl 2024; 63:e202316942. [PMID: 38305637 DOI: 10.1002/anie.202316942] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 01/28/2024] [Accepted: 02/01/2024] [Indexed: 02/03/2024]
Abstract
Self-assemblies (i.e., nanoclusters) of the RAS GTPase on the membrane act as scaffolds that activate downstream RAF kinases and drive MAPK signaling for cell proliferation and tumorigenesis. However, the mechanistic details of nanoclustering remain largely unknown. Here, size-tunable nanodisc platforms and paramagnetic relaxation enhancement (PRE) analyses revealed the structural basis of the cooperative assembly processes of fully processed KRAS, mutated in a quarter of human cancers. The cooperativity is modulated by the mutation and nucleotide states of KRAS and the lipid composition of the membrane. Notably, the oncogenic mutants assemble in nonsequential pathways with two mutually cooperative 'α/α' and 'α/β' interfaces, while α/α dimerization of wild-type KRAS promotes the secondary α/β interaction sequentially. Mutation-based interface engineering was used to selectively trap the oligomeric intermediates of KRAS and probe their favorable interface interactions. Transiently exposed interfaces were available for the assembly. Real-time NMR demonstrated that higher-order oligomers retain higher numbers of active GTP-bound protomers in KRAS GTPase cycling. These data provide a deeper understanding of the nanocluster-enhanced signaling in response to the environment. Furthermore, our methodology is applicable to assemblies of many other membrane GTPases and lipid nanoparticle-based formulations of stable protein oligomers with enhanced cooperativity.
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Affiliation(s)
- Soo-Yeon Lee
- Department of Pharmacy, College of Pharmacy and Institute of Pharmaceutical Sciences, CHA University, Gyeonggi-Do, South Korea
| | - Ki-Young Lee
- Department of Pharmacy, College of Pharmacy and Institute of Pharmaceutical Sciences, CHA University, Gyeonggi-Do, South Korea
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2
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Lee KY. Membrane-Driven Dimerization of the Peripheral Membrane Protein KRAS: Implications for Downstream Signaling. Int J Mol Sci 2024; 25:2530. [PMID: 38473778 DOI: 10.3390/ijms25052530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 02/14/2024] [Accepted: 02/19/2024] [Indexed: 03/14/2024] Open
Abstract
Transient homo-dimerization of the RAS GTPase at the plasma membrane has been shown to promote the mitogen-activated protein kinase (MAPK) signaling pathway essential for cell proliferation and oncogenesis. To date, numerous crystallographic studies have focused on the well-defined GTPase domains of RAS isoforms, which lack the disordered C-terminal membrane anchor, thus providing limited structural insight into membrane-bound RAS molecules. Recently, lipid-bilayer nanodisc platforms and paramagnetic relaxation enhancement (PRE) analyses have revealed several distinct structures of the membrane-anchored homodimers of KRAS, an isoform that is most frequently mutated in human cancers. The KRAS dimerization interface is highly plastic and altered by biologically relevant conditions, including oncogenic mutations, the nucleotide states of the protein, and the lipid composition. Notably, PRE-derived structures of KRAS homodimers on the membrane substantially differ in terms of the relative orientation of the protomers at an "α-α" dimer interface comprising two α4-α5 regions. This interface plasticity along with the altered orientations of KRAS on the membrane impact the accessibility of KRAS to downstream effectors and regulatory proteins. Further, nanodisc platforms used to drive KRAS dimerization can be used to screen potential anticancer drugs that target membrane-bound RAS dimers and probe their structural mechanism of action.
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Affiliation(s)
- Ki-Young Lee
- Department of Pharmacy, College of Pharmacy and Institute of Pharmaceutical Sciences, CHA University, Pocheon-si 11160, Gyeonggi-Do, Republic of Korea
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3
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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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4
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Jurado M, Zorzano A, Castaño O. Cooperativity and oscillations: Regulatory mechanisms of K-Ras nanoclusters. Comput Biol Med 2023; 166:107455. [PMID: 37742420 DOI: 10.1016/j.compbiomed.2023.107455] [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: 11/28/2022] [Revised: 08/07/2023] [Accepted: 09/04/2023] [Indexed: 09/26/2023]
Abstract
K-Ras nanoclusters (NCs) concentrate all required molecules belonging to the extracellular signal-regulated kinase (ERK) mitogen-activated protein kinase (MAPK) pathway in a small area where signaling events take place, increasing efficiency and specificity of signaling. Such nanostructures are characterized by controlled sizes and lifetimes distributions, but there is a poor understanding of the mechanisms involved in their dynamics of growth/decay. Here, a minimum computational model is presented to analyze the behavior of K-Ras NCs as cooperative dynamic structures that self-regulate their growth and decay according to their size. Indeed, the proposed model reveals that the growth and the local production of a K-Ras nanocluster depend positively on its actual size, whilst its lifetime is inversely proportional to the root of its size. The cooperative binding between the structural constituents of the NC (K-Ras proteins) induces oscillations in the size distributions of K-Ras NCs allowing them to range within controlled values, regulating the growth/decay dynamics of these NCs. Thereby, the size of a K-Ras NC is proposed as a key factor to regulate cell signaling, opening a range of possibilities to develop strategies for use in chronic diseases and cancer.
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Affiliation(s)
- Manuel Jurado
- Faculty of Pharmacy, University of Barcelona, Barcelona, Spain
| | - Antonio Zorzano
- Institute for Research in Biomedicine (IRB), Barcelona Institute of Science and Technology (BIST), Barcelona, Spain; CIBER of Diabetes and Associated Metabolic Diseases, Barcelona, Spain; Department of Biochemistry and Molecular Biomedicine, Faculty of Biology, University of Barcelona, Barcelona, Spain.
| | - Oscar Castaño
- Electronics and Biomedical Engineering, Universitat de Barcelona (UB), Barcelona, Spain; Nanobioengineering and Biomaterials, Institute of Nanoscience and Nanotechnology of the University of Barcelona, Barcelona, Spain
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5
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Ingólfsson H, Bhatia H, Aydin F, Oppelstrup T, López CA, Stanton LG, Carpenter TS, Wong S, Di Natale F, Zhang X, Moon JY, Stanley CB, Chavez JR, Nguyen K, Dharuman G, Burns V, Shrestha R, Goswami D, Gulten G, Van QN, Ramanathan A, Van Essen B, Hengartner NW, Stephen AG, Turbyville T, Bremer PT, Gnanakaran S, Glosli JN, Lightstone FC, Nissley DV, Streitz FH. Machine Learning-Driven Multiscale Modeling: Bridging the Scales with a Next-Generation Simulation Infrastructure. J Chem Theory Comput 2023; 19:2658-2675. [PMID: 37075065 PMCID: PMC10173464 DOI: 10.1021/acs.jctc.2c01018] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Indexed: 04/20/2023]
Abstract
Interdependence across time and length scales is common in biology, where atomic interactions can impact larger-scale phenomenon. Such dependence is especially true for a well-known cancer signaling pathway, where the membrane-bound RAS protein binds an effector protein called RAF. To capture the driving forces that bring RAS and RAF (represented as two domains, RBD and CRD) together on the plasma membrane, simulations with the ability to calculate atomic detail while having long time and large length- scales are needed. The Multiscale Machine-Learned Modeling Infrastructure (MuMMI) is able to resolve RAS/RAF protein-membrane interactions that identify specific lipid-protein fingerprints that enhance protein orientations viable for effector binding. MuMMI is a fully automated, ensemble-based multiscale approach connecting three resolution scales: (1) the coarsest scale is a continuum model able to simulate milliseconds of time for a 1 μm2 membrane, (2) the middle scale is a coarse-grained (CG) Martini bead model to explore protein-lipid interactions, and (3) the finest scale is an all-atom (AA) model capturing specific interactions between lipids and proteins. MuMMI dynamically couples adjacent scales in a pairwise manner using machine learning (ML). The dynamic coupling allows for better sampling of the refined scale from the adjacent coarse scale (forward) and on-the-fly feedback to improve the fidelity of the coarser scale from the adjacent refined scale (backward). MuMMI operates efficiently at any scale, from a few compute nodes to the largest supercomputers in the world, and is generalizable to simulate different systems. As computing resources continue to increase and multiscale methods continue to advance, fully automated multiscale simulations (like MuMMI) will be commonly used to address complex science questions.
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Affiliation(s)
- Helgi
I. Ingólfsson
- Physical
and Life Sciences (PLS) Directorate, Lawrence
Livermore National Laboratory, Livermore, California 94550, United States
| | - Harsh Bhatia
- Computing
Directorate, Lawrence Livermore National
Laboratory, Livermore, California 94550, United States
| | - Fikret Aydin
- Physical
and Life Sciences (PLS) Directorate, Lawrence
Livermore National Laboratory, Livermore, California 94550, United States
| | - Tomas Oppelstrup
- Physical
and Life Sciences (PLS) Directorate, Lawrence
Livermore National Laboratory, Livermore, California 94550, United States
| | - Cesar A. López
- Theoretical
Biology and Biophysics Group, Los Alamos
National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Liam G. Stanton
- Department
of Mathematics and Statistics, San José
State University, San José, California 95192, United States
| | - Timothy S. Carpenter
- Physical
and Life Sciences (PLS) Directorate, Lawrence
Livermore National Laboratory, Livermore, California 94550, United States
| | - Sergio Wong
- Physical
and Life Sciences (PLS) Directorate, Lawrence
Livermore National Laboratory, Livermore, California 94550, United States
| | - Francesco Di Natale
- Computing
Directorate, Lawrence Livermore National
Laboratory, Livermore, California 94550, United States
| | - Xiaohua Zhang
- Physical
and Life Sciences (PLS) Directorate, Lawrence
Livermore National Laboratory, Livermore, California 94550, United States
| | - Joseph Y. Moon
- Computing
Directorate, Lawrence Livermore National
Laboratory, Livermore, California 94550, United States
| | - Christopher B. Stanley
- Computational
Sciences and Engineering Division, Oak Ridge
National Laboratory, Oak Ridge, Tennessee 37830, United States
| | - Joseph R. Chavez
- Computing
Directorate, Lawrence Livermore National
Laboratory, Livermore, California 94550, United States
| | - Kien Nguyen
- Theoretical
Biology and Biophysics Group, Los Alamos
National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Gautham Dharuman
- Physical
and Life Sciences (PLS) Directorate, Lawrence
Livermore National Laboratory, Livermore, California 94550, United States
| | - Violetta Burns
- Theoretical
Biology and Biophysics Group, Los Alamos
National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Rebika Shrestha
- RAS Initiative,
The Cancer Research Technology Program, Frederick National Laboratory, Frederick, Maryland 21701, United States
| | - Debanjan Goswami
- RAS Initiative,
The Cancer Research Technology Program, Frederick National Laboratory, Frederick, Maryland 21701, United States
| | - Gulcin Gulten
- RAS Initiative,
The Cancer Research Technology Program, Frederick National Laboratory, Frederick, Maryland 21701, United States
| | - Que N. Van
- RAS Initiative,
The Cancer Research Technology Program, Frederick National Laboratory, Frederick, Maryland 21701, United States
| | - Arvind Ramanathan
- Computing,
Environment & Life Sciences (CELS) Directorate, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Brian Van Essen
- Computing
Directorate, Lawrence Livermore National
Laboratory, Livermore, California 94550, United States
| | - Nicolas W. Hengartner
- Theoretical
Biology and Biophysics Group, Los Alamos
National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Andrew G. Stephen
- RAS Initiative,
The Cancer Research Technology Program, Frederick National Laboratory, Frederick, Maryland 21701, United States
| | - Thomas Turbyville
- RAS Initiative,
The Cancer Research Technology Program, Frederick National Laboratory, Frederick, Maryland 21701, United States
| | - Peer-Timo Bremer
- Computing
Directorate, Lawrence Livermore National
Laboratory, Livermore, California 94550, United States
| | - S. Gnanakaran
- Theoretical
Biology and Biophysics Group, Los Alamos
National Laboratory, Los Alamos, New Mexico 87545, United States
| | - James N. Glosli
- Physical
and Life Sciences (PLS) Directorate, Lawrence
Livermore National Laboratory, Livermore, California 94550, United States
| | - Felice C. Lightstone
- Physical
and Life Sciences (PLS) Directorate, Lawrence
Livermore National Laboratory, Livermore, California 94550, United States
| | - Dwight V. Nissley
- RAS Initiative,
The Cancer Research Technology Program, Frederick National Laboratory, Frederick, Maryland 21701, United States
| | - Frederick H. Streitz
- Physical
and Life Sciences (PLS) Directorate, Lawrence
Livermore National Laboratory, Livermore, California 94550, United States
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6
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Lee KY, Ikura M, Marshall CB. The Self-Association of the KRAS4b Protein is Altered by Lipid-Bilayer Composition and Electrostatics. Angew Chem Int Ed Engl 2023; 62:e202218698. [PMID: 36883374 DOI: 10.1002/anie.202218698] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2022] [Revised: 02/07/2023] [Accepted: 03/07/2023] [Indexed: 03/09/2023]
Abstract
KRAS is a peripheral membrane protein that regulates multiple signaling pathways, and is mutated in ≈30 % of cancers. Transient self-association of KRAS is essential for activation of the downstream effector RAF and oncogenicity. The presence of anionic phosphatidylserine (PS) lipids in the membrane was shown to promote KRAS self-assembly, however, the structural mechanisms remain elusive. Here, we employed nanodisc bilayers of defined lipid compositions, and probed the impact of PS concentration on KRAS self-association. Paramagnetic NMR experiments demonstrated the existence of two transient dimer conformations involving alternate electrostatic contacts between R135 and either D153 or E168 on the "α4/5-α4/5" interface, and revealed that lipid composition and salt modulate their dynamic equilibrium. These dimer interfaces were validated by charge-reversal mutants. This plasticity demonstrates how the dynamic KRAS dimerization interface responds to the environment, and likely extends to the assembly of other signaling complexes on the membrane.
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Affiliation(s)
- Ki-Young Lee
- Department of Pharmacy, College of Pharmacy and Institute of Pharmaceutical Sciences, CHA University, Gyeonggi-Do, South Korea
| | - Mitsuhiko Ikura
- Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, M5G 1L7, Canada
| | - Christopher B Marshall
- Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, M5G 1L7, Canada
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7
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Mouro PR, Sanches MN, Leite VBP, Chahine J. Exploring the Folding Mechanism of Dimeric Superoxide Dismutase. J Phys Chem B 2023; 127:1338-1349. [PMID: 36716437 DOI: 10.1021/acs.jpcb.2c08877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The Cu/Zn Human Superoxide Dismutase (SOD1) is a dimeric metalloenzyme whose genetic mutations are directly related to amyotrophic lateral sclerosis (ALS), so understanding its folding mechanism is of fundamental importance. Currently, the SOD1 dimer formation is studied via molecular dynamics simulations using a simplified structure-based model and an all-atom model. Results from the simplified model reveal a mechanism dependent on distances between monomers, which are limited by constraints to mimic concentration dependence. The stability of intermediates (during the int state) is significantly affected by this distance, as well as by the presence of two folded monomers prior to dimer formation. The kinetics of interface formation are also highly dependent on the separation distance. The folding temperature of the dimer is about 4.2% higher than that of the monomer, a value not too different from experimental data. All-atom simulations on the apo dimer give binding free energy between monomers similar to experimental values. An intermediate state is evident for the apo form at a separation distance between monomers slightly larger than the native distance which has little formed interface between monomers. We have shown that this intermediate is stabilized by non-native intra- and intercontacts.
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Affiliation(s)
- Paulo R Mouro
- São Paulo State University (UNESP), IBILCE, São José do Rio Preto15054-000, Brazil
| | - Murilo N Sanches
- São Paulo State University (UNESP), IBILCE, São José do Rio Preto15054-000, Brazil
| | - Vitor B P Leite
- São Paulo State University (UNESP), IBILCE, São José do Rio Preto15054-000, Brazil
| | - Jorge Chahine
- São Paulo State University (UNESP), IBILCE, São José do Rio Preto15054-000, Brazil
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8
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Abuasaker B, Garrido E, Vilaplana M, Gómez-Zepeda JD, Brun S, Garcia-Cajide M, Mauvezin C, Jaumot M, Pujol MD, Rubio-Martínez J, Agell N. α4-α5 Helices on Surface of KRAS Can Accommodate Small Compounds That Increase KRAS Signaling While Inducing CRC Cell Death. Int J Mol Sci 2023; 24:ijms24010748. [PMID: 36614192 PMCID: PMC9821572 DOI: 10.3390/ijms24010748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Revised: 12/28/2022] [Accepted: 12/29/2022] [Indexed: 01/03/2023] Open
Abstract
KRAS is the most frequently mutated oncogene associated with the genesis and progress of pancreatic, lung and colorectal (CRC) tumors. KRAS has always been considered as a therapeutic target in cancer but until now only two compounds that inhibit one specific KRAS mutation have been approved for clinical use. In this work, by molecular dynamics and a docking process, we describe a new compound (P14B) that stably binds to a druggable pocket near the α4-α5 helices of the allosteric domain of KRAS. This region had previously been identified as the binding site for calmodulin (CaM). Using surface plasmon resonance and pulldown analyses, we prove that P14B binds directly to oncogenic KRAS thus competing with CaM. Interestingly, P14B favors oncogenic KRAS interaction with BRAF and phosphorylated C-RAF, and increases downstream Ras signaling in CRC cells expressing oncogenic KRAS. The viability of these cells, but not that of the normal cells, is impaired by P14B treatment. These data support the significance of the α4-α5 helices region of KRAS in the regulation of oncogenic KRAS signaling, and demonstrate that drugs interacting with this site may destine CRC cells to death by increasing oncogenic KRAS downstream signaling.
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Affiliation(s)
- Baraa Abuasaker
- Departament de Biomedicina, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, 08036 Barcelona, Spain
| | - Eduardo Garrido
- Departament de Biomedicina, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, 08036 Barcelona, Spain
- Departament de Ciència de Materials i Química Física, Facultat de Química, Universitat de Barcelona & Institut de Recerca en Química Teòrica i Computacional (IQTCUB), 08028 Barcelona, Spain
| | - Marta Vilaplana
- Departament de Farmacologia, Toxicologia i Química Terapèutica, Facultat de Farmàcia i Ciències de l’Alimentació, Universitat de Barcelona, 08028 Barcelona, Spain
| | - Jesús Daniel Gómez-Zepeda
- Departament de Biomedicina, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, 08036 Barcelona, Spain
| | - Sonia Brun
- Departament de Biomedicina, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, 08036 Barcelona, Spain
| | - Marta Garcia-Cajide
- Departament de Biomedicina, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, 08036 Barcelona, Spain
| | - Caroline Mauvezin
- Departament de Biomedicina, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, 08036 Barcelona, Spain
| | - Montserrat Jaumot
- Departament de Biomedicina, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, 08036 Barcelona, Spain
| | - Maria Dolors Pujol
- Departament de Farmacologia, Toxicologia i Química Terapèutica, Facultat de Farmàcia i Ciències de l’Alimentació, Universitat de Barcelona, 08028 Barcelona, Spain
| | - Jaime Rubio-Martínez
- Departament de Ciència de Materials i Química Física, Facultat de Química, Universitat de Barcelona & Institut de Recerca en Química Teòrica i Computacional (IQTCUB), 08028 Barcelona, Spain
- Correspondence: (J.R.-M.); (N.A.); Tel.: +34-934039263 (J.R.-M.); +34-934035267 (N.A.)
| | - Neus Agell
- Departament de Biomedicina, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, 08036 Barcelona, Spain
- Correspondence: (J.R.-M.); (N.A.); Tel.: +34-934039263 (J.R.-M.); +34-934035267 (N.A.)
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9
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Hsueh SCC, Nijland M, Peng X, Hilton B, Plotkin SS. First Principles Calculation of Protein-Protein Dimer Affinities of ALS-Associated SOD1 Mutants. Front Mol Biosci 2022; 9:845013. [PMID: 35402516 PMCID: PMC8988244 DOI: 10.3389/fmolb.2022.845013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Accepted: 02/08/2022] [Indexed: 01/03/2023] Open
Abstract
Cu,Zn superoxide dismutase (SOD1) is a 32 kDa homodimer that converts toxic oxygen radicals in neurons to less harmful species. The dimerization of SOD1 is essential to the stability of the protein. Monomerization increases the likelihood of SOD1 misfolding into conformations associated with aggregation, cellular toxicity, and neuronal death in familial amyotrophic lateral sclerosis (fALS). The ubiquity of disease-associated mutations throughout the primary sequence of SOD1 suggests an important role of physicochemical processes, including monomerization of SOD1, in the pathology of the disease. Herein, we use a first-principles statistical mechanics method to systematically calculate the free energy of dimer binding for SOD1 using molecular dynamics, which involves sequentially computing conformational, orientational, and separation distance contributions to the binding free energy. We consider the effects of two ALS-associated mutations in SOD1 protein on dimer stability, A4V and D101N, as well as the role of metal binding and disulfide bond formation. We find that the penalty for dimer formation arising from the conformational entropy of disordered loops in SOD1 is significantly larger than that for other protein-protein interactions previously considered. In the case of the disulfide-reduced protein, this leads to a bound complex whose formation is energetically disfavored. Somewhat surprisingly, the loop free energy penalty upon dimerization is still significant for the holoprotein, despite the increased structural order induced by the bound metal cations. This resulted in a surprisingly modest increase in dimer binding free energy of only about 1.5 kcal/mol upon metalation of the protein, suggesting that the most significant stabilizing effects of metalation are on folding stability rather than dimer binding stability. The mutant A4V has an unstable dimer due to weakened monomer-monomer interactions, which are manifested in the calculation by a separation free energy surface with a lower barrier. The mutant D101N has a stable dimer partially due to an unusually rigid β-barrel in the free monomer. D101N also exhibits anticooperativity in loop folding upon dimerization. These computational calculations are, to our knowledge, the most quantitatively accurate calculations of dimer binding stability in SOD1 to date.
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Affiliation(s)
- Shawn C. C. Hsueh
- Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada
| | - Mark Nijland
- Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada
- Laboratory of Organic Chemistry, Wageningen University and Research, Wageningen, Netherlands
- Laboratory of Physical Chemistry and Soft Matter, Wageningen University and Research, Wageningen, Netherlands
| | - Xubiao Peng
- Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada
- Center for Quantum Technology Research, School of Physics, Beijing Institute of Technology, Beijing, China
| | - Benjamin Hilton
- Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada
- Imperial College London, London, United Kingdom
| | - Steven S. Plotkin
- Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada
- Genome Science and Technology Program, University of British Columbia, Vancouver, BC, Canada
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10
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Ozdemir ES, Koester AM, Nan X. Ras Multimers on the Membrane: Many Ways for a Heart-to-Heart Conversation. Genes (Basel) 2022; 13:219. [PMID: 35205266 PMCID: PMC8872464 DOI: 10.3390/genes13020219] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 01/20/2022] [Accepted: 01/21/2022] [Indexed: 12/31/2022] Open
Abstract
Formation of Ras multimers, including dimers and nanoclusters, has emerged as an exciting, new front of research in the 'old' field of Ras biomedicine. With significant advances made in the past few years, we are beginning to understand the structure of Ras multimers and, albeit preliminary, mechanisms that regulate their formation in vitro and in cells. Here we aim to synthesize the knowledge accrued thus far on Ras multimers, particularly the presence of multiple globular (G-) domain interfaces, and discuss how membrane nanodomain composition and structure would influence Ras multimer formation. We end with some general thoughts on the potential implications of Ras multimers in basic and translational biology.
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Affiliation(s)
- E. Sila Ozdemir
- Cancer Early Detection Advanced Research Center, Knight Cancer Institute, Oregon Health & Science University, 2720 S Moody Ave., Portland, OR 97201, USA;
| | - Anna M. Koester
- Program in Quantitative and Systems Biology, Department of Biomedical Engineering, Oregon Health & Science University, 2730 S Moody Ave., Portland, OR 97201, USA;
| | - Xiaolin Nan
- Cancer Early Detection Advanced Research Center, Knight Cancer Institute, Oregon Health & Science University, 2720 S Moody Ave., Portland, OR 97201, USA;
- Program in Quantitative and Systems Biology, Department of Biomedical Engineering, Oregon Health & Science University, 2730 S Moody Ave., Portland, OR 97201, USA;
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11
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Wakchaure PD, Ganguly B. Deciphering the mechanism of action of 5FDQD and the design of new neutral analogues for the FMN riboswitch: a well-tempered metadynamics simulation study. Phys Chem Chem Phys 2022; 24:817-828. [PMID: 34928280 DOI: 10.1039/d1cp01348c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The FMN riboswitch is a novel drug target for the design of new antibiotics, and efforts have been made to design new charged and uncharged ligands. Uncharged ligands have shown advantages of not requiring any transporter for intracellular transport or proteins for their phosphorylation. 5FDQD (5-(3-(4-fluorophenyl)butyl)-7,8-dimethylpyrido(3,4-b)quinoxaline-1,3(2H,5H)-dione) is a recently reported neutral ligand for the FMN riboswitch active against Clostridium difficile infection in mice. However, the crystal structure of the 5FDQD bound FMN riboswitch is not available, and the mechanism of ligand binding and triggering the function of the riboswitch is not well understood. We have examined 5FDQD for its binding affinity with the FMN riboswitch using the well-tempered metadynamics (WT-MtD) simulation technique. The crystal structure of the FMN riboswitch shows that the FMN interacts with the J4/5 region through the phosphate group with G62; however, the uncharged ligands take advantage of π-π stacking interactions with the same residue of the riboswitch observed from the WT-MtD simulation results. The simulation results show that the presence of fluorine on the phenyl ring in 5FDQD is important to enhance the binding affinity of the neutral ligands with the FMN riboswitch. The WT-MtD results showed that the 1,2-difluoro substitution on the phenyl ring in 5FDQD (FMN-difluoro2) and the 1,3 positions in the phenyl ring (FMN-difluoro1) showed weaker binding energy with the FMN riboswitch compared to 5FDQD. The substitution of another fluorine atom at the 5-position of the phenyl ring (FMN-trifluoro) showed a comparable binding affinity (∼-31.4 kcal mol-1) to 5FDQD. Electron-donating substitution on the phenyl ring such as the amino group also lowered the binding affinity (-28.8 kcal mol-1) with the riboswitch compared to 5FDQD. The computed results suggest that the position and nature of substitution in the phenyl ring of the uncharged ligands affect the overall binding and such a delicate balance is important to achieve superior binding affinity with the FMN riboswitch.
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Affiliation(s)
- Padmaja D Wakchaure
- Computation and Simulation Unit (Analytical Discipline and Centralized Instrument Facility), CSIR-Central Salt and Marine Chemicals Research Institute, Bhavnagar-364002, Gujarat, India.,Academy of Scientific and Innovative Research, Ghaziabad, Uttar Pradesh-201 002, India.
| | - Bishwajit Ganguly
- Computation and Simulation Unit (Analytical Discipline and Centralized Instrument Facility), CSIR-Central Salt and Marine Chemicals Research Institute, Bhavnagar-364002, Gujarat, India.,Academy of Scientific and Innovative Research, Ghaziabad, Uttar Pradesh-201 002, India.
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12
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Ingólfsson HI, Neale C, Carpenter TS, Shrestha R, López CA, Tran TH, Oppelstrup T, Bhatia H, Stanton LG, Zhang X, Sundram S, Di Natale F, Agarwal A, Dharuman G, Kokkila Schumacher SIL, Turbyville T, Gulten G, Van QN, Goswami D, Jean-Francois F, Agamasu C, Chen D, Hettige JJ, Travers T, Sarkar S, Surh MP, Yang Y, Moody A, Liu S, Van Essen BC, Voter AF, Ramanathan A, Hengartner NW, Simanshu DK, Stephen AG, Bremer PT, Gnanakaran S, Glosli JN, Lightstone FC, McCormick F, Nissley DV, Streitz FH. Machine learning-driven multiscale modeling reveals lipid-dependent dynamics of RAS signaling proteins. Proc Natl Acad Sci U S A 2022; 119:e2113297119. [PMID: 34983849 PMCID: PMC8740753 DOI: 10.1073/pnas.2113297119] [Citation(s) in RCA: 44] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/24/2021] [Indexed: 01/17/2023] Open
Abstract
RAS is a signaling protein associated with the cell membrane that is mutated in up to 30% of human cancers. RAS signaling has been proposed to be regulated by dynamic heterogeneity of the cell membrane. Investigating such a mechanism requires near-atomistic detail at macroscopic temporal and spatial scales, which is not possible with conventional computational or experimental techniques. We demonstrate here a multiscale simulation infrastructure that uses machine learning to create a scale-bridging ensemble of over 100,000 simulations of active wild-type KRAS on a complex, asymmetric membrane. Initialized and validated with experimental data (including a new structure of active wild-type KRAS), these simulations represent a substantial advance in the ability to characterize RAS-membrane biology. We report distinctive patterns of local lipid composition that correlate with interfacially promiscuous RAS multimerization. These lipid fingerprints are coupled to RAS dynamics, predicted to influence effector binding, and therefore may be a mechanism for regulating cell signaling cascades.
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Affiliation(s)
- Helgi I Ingólfsson
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA 94550
| | - Chris Neale
- Theoretical Biology and Biophysics Group, Los Alamos National Laboratory, Los Alamos, NM 87545
| | - Timothy S Carpenter
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA 94550
| | - Rebika Shrestha
- RAS Initiative, The Cancer Research Technology Program, Frederick National Laboratory, Frederick, MD 21701
| | - Cesar A López
- Theoretical Biology and Biophysics Group, Los Alamos National Laboratory, Los Alamos, NM 87545
| | - Timothy H Tran
- RAS Initiative, The Cancer Research Technology Program, Frederick National Laboratory, Frederick, MD 21701
| | - Tomas Oppelstrup
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA 94550
| | - Harsh Bhatia
- Computing Directorate, Lawrence Livermore National Laboratory, Livermore, CA 94550
| | - Liam G Stanton
- Department of Mathematics and Statistics, San José State University, San José, CA 95192
| | - Xiaohua Zhang
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA 94550
| | - Shiv Sundram
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA 94550
| | - Francesco Di Natale
- Computing Directorate, Lawrence Livermore National Laboratory, Livermore, CA 94550
| | - Animesh Agarwal
- Theoretical Biology and Biophysics Group, Los Alamos National Laboratory, Los Alamos, NM 87545
| | - Gautham Dharuman
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA 94550
| | | | - Thomas Turbyville
- RAS Initiative, The Cancer Research Technology Program, Frederick National Laboratory, Frederick, MD 21701
| | - Gulcin Gulten
- RAS Initiative, The Cancer Research Technology Program, Frederick National Laboratory, Frederick, MD 21701
| | - Que N Van
- RAS Initiative, The Cancer Research Technology Program, Frederick National Laboratory, Frederick, MD 21701
| | - Debanjan Goswami
- RAS Initiative, The Cancer Research Technology Program, Frederick National Laboratory, Frederick, MD 21701
| | - Frantz Jean-Francois
- RAS Initiative, The Cancer Research Technology Program, Frederick National Laboratory, Frederick, MD 21701
| | - Constance Agamasu
- RAS Initiative, The Cancer Research Technology Program, Frederick National Laboratory, Frederick, MD 21701
| | - De Chen
- RAS Initiative, The Cancer Research Technology Program, Frederick National Laboratory, Frederick, MD 21701
| | - Jeevapani J Hettige
- Theoretical Biology and Biophysics Group, Los Alamos National Laboratory, Los Alamos, NM 87545
| | - Timothy Travers
- Theoretical Biology and Biophysics Group, Los Alamos National Laboratory, Los Alamos, NM 87545
| | - Sumantra Sarkar
- Center for Nonlinear Studies, Los Alamos National Laboratory, Los Alamos, NM 87545
| | - Michael P Surh
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA 94550
| | - Yue Yang
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA 94550
| | - Adam Moody
- Computing Directorate, Lawrence Livermore National Laboratory, Livermore, CA 94550
| | - Shusen Liu
- Computing Directorate, Lawrence Livermore National Laboratory, Livermore, CA 94550
| | - Brian C Van Essen
- Computing Directorate, Lawrence Livermore National Laboratory, Livermore, CA 94550
| | - Arthur F Voter
- Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM 87545
| | - Arvind Ramanathan
- Computing, Environment & Life Sciences Directorate, Argonne National Laboratory, Lemont, IL 60439
| | - Nicolas W Hengartner
- Theoretical Biology and Biophysics Group, Los Alamos National Laboratory, Los Alamos, NM 87545
| | - Dhirendra K Simanshu
- RAS Initiative, The Cancer Research Technology Program, Frederick National Laboratory, Frederick, MD 21701
| | - Andrew G Stephen
- RAS Initiative, The Cancer Research Technology Program, Frederick National Laboratory, Frederick, MD 21701
| | - Peer-Timo Bremer
- Computing Directorate, Lawrence Livermore National Laboratory, Livermore, CA 94550
| | - S Gnanakaran
- Theoretical Biology and Biophysics Group, Los Alamos National Laboratory, Los Alamos, NM 87545
| | - James N Glosli
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA 94550
| | - Felice C Lightstone
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA 94550
| | - Frank McCormick
- RAS Initiative, The Cancer Research Technology Program, Frederick National Laboratory, Frederick, MD 21701;
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, CA 94115
| | - Dwight V Nissley
- RAS Initiative, The Cancer Research Technology Program, Frederick National Laboratory, Frederick, MD 21701;
| | - Frederick H Streitz
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA 94550;
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13
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Lee KY, Enomoto M, Gebregiworgis T, Gasmi-Seabrook GMC, Ikura M, Marshall CB. Oncogenic KRAS G12D mutation promotes dimerization through a second, phosphatidylserine-dependent interface: a model for KRAS oligomerization. Chem Sci 2021; 12:12827-12837. [PMID: 34703570 PMCID: PMC8494122 DOI: 10.1039/d1sc03484g] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Accepted: 09/04/2021] [Indexed: 12/02/2022] Open
Abstract
KRAS forms transient dimers and higher-order multimers (nanoclusters) on the plasma membrane, which drive MAPK signaling and cell proliferation. KRAS is a frequently mutated oncogene, and while it is well known that the most prevalent mutation, G12D, impairs GTP hydrolysis, thereby increasing KRAS activation, G12D has also been shown to enhance nanoclustering. Elucidating structures of dynamic KRAS assemblies on a membrane has been challenging, thus we have refined our NMR approach that uses nanodiscs to study KRAS associated with membranes. We incorporated paramagnetic relaxation enhancement (PRE) titrations and interface mutagenesis, which revealed that, in addition to the symmetric ‘α–α’ dimerization interface shared with wild-type KRAS, the G12D mutant also self-associates through an asymmetric ‘α–β’ interface. The ‘α–β’ association is dependent on the presence of phosphatidylserine lipids, consistent with previous reports that this lipid promotes KRAS self-assembly on the plasma membrane in cells. Experiments using engineered mutants to spoil each interface, together with PRE probes attached to the membrane or free in solvent, suggest that dimerization through the primary ‘α–α’ interface releases β interfaces from the membrane promoting formation of the secondary ‘α–β’ interaction, potentially initiating nanoclustering. In addition, the small molecule BI-2852 binds at a β–β interface, stabilizing a new dimer configuration that outcompetes native dimerization and blocks the effector-binding site. Our data indicate that KRAS self-association involves a delicately balanced conformational equilibrium between transient states, which is sensitive to disease-associated mutation and small molecule inhibitors. The methods developed here are applicable to biologically important transient interactions involving other membrane-associated proteins. Studies of membrane-dependent dimerization of KRAS on nanodiscs using paramagnetic NMR titrations and mutagenesis revealed a novel asymmetric ‘α–β’ interface that provides a potential mechanism for the enhanced assembly of KRAS–G12D nanoclusters.![]()
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Affiliation(s)
- Ki-Young Lee
- Princess Margaret Cancer Centre, University Health Network Toronto Ontario M5G 1L7 Canada
| | - Masahiro Enomoto
- Princess Margaret Cancer Centre, University Health Network Toronto Ontario M5G 1L7 Canada
| | - Teklab Gebregiworgis
- Princess Margaret Cancer Centre, University Health Network Toronto Ontario M5G 1L7 Canada
| | | | - Mitsuhiko Ikura
- Princess Margaret Cancer Centre, University Health Network Toronto Ontario M5G 1L7 Canada .,Department of Medical Biophysics, University of Toronto Toronto Ontario M5G 1L7 Canada
| | - Christopher B Marshall
- Princess Margaret Cancer Centre, University Health Network Toronto Ontario M5G 1L7 Canada
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14
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RAS Dimers: The Novice Couple at the RAS-ERK Pathway Ball. Genes (Basel) 2021; 12:genes12101556. [PMID: 34680951 PMCID: PMC8535645 DOI: 10.3390/genes12101556] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 09/27/2021] [Accepted: 09/28/2021] [Indexed: 02/07/2023] Open
Abstract
Signals conveyed through the RAS-ERK pathway constitute a pivotal regulatory element in cancer-related cellular processes. Recently, RAS dimerization has been proposed as a key step in the relay of RAS signals, critically contributing to RAF activation. RAS clustering at plasma membrane microdomains and endomembranes facilitates RAS dimerization in response to stimulation, promoting RAF dimerization and subsequent activation. Remarkably, inhibiting RAS dimerization forestalls tumorigenesis in cellular and animal models. Thus, the pharmacological disruption of RAS dimers has emerged as an additional target for cancer researchers in the quest for a means to curtail aberrant RAS activity.
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15
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Zhou Y, Gorfe AA, Hancock JF. RAS Nanoclusters Selectively Sort Distinct Lipid Headgroups and Acyl Chains. Front Mol Biosci 2021; 8:686338. [PMID: 34222339 PMCID: PMC8245699 DOI: 10.3389/fmolb.2021.686338] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Accepted: 05/13/2021] [Indexed: 12/12/2022] Open
Abstract
RAS proteins are lipid-anchored small GTPases that switch between the GTP-bound active and GDP-bound inactive states. RAS isoforms, including HRAS, NRAS and splice variants KRAS4A and KRAS4B, are some of the most frequently mutated proteins in cancer. In particular, constitutively active mutants of KRAS comprise ∼80% of all RAS oncogenic mutations and are found in 98% of pancreatic, 45% of colorectal and 31% of lung tumors. Plasma membrane (PM) is the primary location of RAS signaling in biology and pathology. Thus, a better understanding of how RAS proteins localize to and distribute on the PM is critical to better comprehend RAS biology and to develop new strategies to treat RAS pathology. In this review, we discuss recent findings on how RAS proteins sort lipids as they undergo macromolecular assembly on the PM. We also discuss how RAS/lipid nanoclusters serve as signaling platforms for the efficient recruitment of effectors and signal transduction, and how perturbing the PM biophysical properties affect the spatial distribution of RAS isoforms and their functions.
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Affiliation(s)
- Yong Zhou
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center, Houston, TX, United States
| | - Alemayehu A. Gorfe
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center, Houston, TX, United States
| | - John F. Hancock
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center, Houston, TX, United States
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16
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Packer MR, Parker JA, Chung JK, Li Z, Lee YK, Cookis T, Guterres H, Alvarez S, Hossain MA, Donnelly DP, Agar JN, Makowski L, Buck M, Groves JT, Mattos C. Raf promotes dimerization of the Ras G-domain with increased allosteric connections. Proc Natl Acad Sci U S A 2021; 118:e2015648118. [PMID: 33653954 PMCID: PMC7958358 DOI: 10.1073/pnas.2015648118] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Ras dimerization is critical for Raf activation. Here we show that the Ras binding domain of Raf (Raf-RBD) induces robust Ras dimerization at low surface densities on supported lipid bilayers and, to a lesser extent, in solution as observed by size exclusion chromatography and confirmed by SAXS. Community network analysis based on molecular dynamics simulations shows robust allosteric connections linking the two Raf-RBD D113 residues located in the Galectin scaffold protein binding site of each Raf-RBD molecule and 85 Å apart on opposite ends of the dimer complex. Our results suggest that Raf-RBD binding and Ras dimerization are concerted events that lead to a high-affinity signaling complex at the membrane that we propose is an essential unit in the macromolecular assembly of higher order Ras/Raf/Galectin complexes important for signaling through the Ras/Raf/MEK/ERK pathway.
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Affiliation(s)
- Morgan R Packer
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA 02115
| | - Jillian A Parker
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA 02115
| | - Jean K Chung
- Department of Chemistry, University of California, Berkeley, CA 94720
| | - Zhenlu Li
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, OH 44106
| | - Young Kwang Lee
- Department of Chemistry, University of California, Berkeley, CA 94720
| | - Trinity Cookis
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA 02115
| | - Hugo Guterres
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA 02115
| | - Steven Alvarez
- Department of Chemistry, University of California, Berkeley, CA 94720
- Department of Materials Science and Engineering, University of California, Berkeley, CA 94720
| | - Md Amin Hossain
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA 02115
| | - Daniel P Donnelly
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA 02115
| | - Jeffrey N Agar
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA 02115
- Department of Pharmaceutical Sciences, Northeastern University, Boston, MA 02115
| | - Lee Makowski
- Department of Bioengineering, Northeastern University, Boston, MA 02115
| | - Matthias Buck
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, OH 44106
| | - Jay T Groves
- Department of Chemistry, University of California, Berkeley, CA 94720
| | - Carla Mattos
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA 02115;
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17
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Van QN, Prakash P, Shrestha R, Balius TE, Turbyville TJ, Stephen AG. RAS Nanoclusters: Dynamic Signaling Platforms Amenable to Therapeutic Intervention. Biomolecules 2021; 11:377. [PMID: 33802474 PMCID: PMC8000715 DOI: 10.3390/biom11030377] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2021] [Revised: 02/24/2021] [Accepted: 02/24/2021] [Indexed: 01/18/2023] Open
Abstract
RAS proteins are mutated in approximately 20% of all cancers and are generally associated with poor clinical outcomes. RAS proteins are localized to the plasma membrane and function as molecular switches, turned on by partners that receive extracellular mitogenic signals. In the on-state, they activate intracellular signal transduction cascades. Membrane-bound RAS molecules segregate into multimers, known as nanoclusters. These nanoclusters, held together through weak protein-protein and protein-lipid associations, are highly dynamic and respond to cellular input signals and fluctuations in the local lipid environment. Disruption of RAS nanoclusters results in downregulation of RAS-mediated mitogenic signaling. In this review, we discuss the propensity of RAS proteins to display clustering behavior and the interfaces that are associated with these assemblies. Strategies to therapeutically disrupt nanocluster formation or the stabilization of signaling incompetent RAS complexes are discussed.
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Affiliation(s)
| | | | | | | | | | - Andrew G. Stephen
- Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, National Cancer Institute RAS Initiative, Inc., Frederick, MD 21702, USA; (Q.N.V.); (P.P.); (R.S.); (T.E.B.); (T.J.T.)
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18
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Gorfe AA, Cho KJ. Approaches to inhibiting oncogenic K-Ras. Small GTPases 2021; 12:96-105. [PMID: 31438765 PMCID: PMC7849769 DOI: 10.1080/21541248.2019.1655883] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Revised: 07/29/2019] [Accepted: 08/06/2019] [Indexed: 02/06/2023] Open
Abstract
Activating somatic K-Ras mutations are associated with >15% all human tumors and up to 90% of specific tumor types such as pancreatic cancer. Successfully inhibiting abnormal K-Ras signaling would therefore be a game changer in cancer therapy. However, K-Ras has long been considered an undruggable target for various reasons. This view is now changing by the discovery of allosteric inhibitors that directly target K-Ras and inhibit its functions, and by the identification of new mechanisms to dislodge it from the plasma membrane and thereby abrogate its cellular activities. In this review, we will discuss recent progresses and challenges to inhibiting aberrant K-Ras functions by these two approaches. We will also provide a broad overview of other approaches such as inhibition of K-Ras effectors, and offer a brief perspective on the way forward.
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Affiliation(s)
- Alemayehu A. Gorfe
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, USA
- Programs of Biochemistry & Cell and Therapeutics & Pharmacology, MD Anderson UTHealth Graduate School of Biomedical Sciences, Houston, TX, USA
| | - Kwang-Jin Cho
- Department of Biochemistry and Molecular Biology, Boonshoft School of Medicine, Wright State University, Dayton, OH, USA
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19
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Abankwa D, Gorfe AA. Mechanisms of Ras Membrane Organization and Signaling: Ras Rocks Again. Biomolecules 2020; 10:E1522. [PMID: 33172116 PMCID: PMC7694788 DOI: 10.3390/biom10111522] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 11/03/2020] [Accepted: 11/04/2020] [Indexed: 12/17/2022] Open
Abstract
Ras is the most frequently mutated oncogene and recent drug development efforts have spurred significant new research interest. Here we review progress toward understanding how Ras functions in nanoscale, proteo-lipid signaling complexes on the plasma membrane, called nanoclusters. We discuss how G-domain reorientation is plausibly linked to Ras-nanoclustering and -dimerization. We then look at how these mechanistic features could cooperate in the engagement and activation of RAF by Ras. Moreover, we show how this structural information can be integrated with microscopy data that provide nanoscale resolution in cell biological experiments. Synthesizing the available data, we propose to distinguish between two types of Ras nanoclusters, an active, immobile RAF-dependent type and an inactive/neutral membrane anchor-dependent. We conclude that it is possible that Ras reorientation enables dynamic Ras dimerization while the whole Ras/RAF complex transits into an active state. These transient di/oligomer interfaces of Ras may be amenable to pharmacological intervention. We close by highlighting a number of open questions including whether all effectors form active nanoclusters and whether there is an isoform specific composition of Ras nanocluster.
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Affiliation(s)
- Daniel Abankwa
- Cancer Cell Biology and Drug Discovery Group, Department of Life Sciences and Medicine, University of Luxembourg, Esch-sur-Alzette 4362, Luxembourg
| | - Alemayehu A. Gorfe
- Department of Integrative Biology and Pharmacology, McGovern Medical School, University of Texas Health Science Center at Houston, 6431 Fannin St., Houston, TX 77030, USA
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20
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How to make an undruggable enzyme druggable: lessons from ras proteins. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2020. [PMID: 32951811 DOI: 10.1016/bs.apcsb.2020.05.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2023]
Abstract
Significant advances have been made toward discovering allosteric inhibitors for challenging drug targets such as the Ras family of membrane-associated signaling proteins. Malfunction of Ras proteins due to somatic mutations is associated with up to a quarter of all human cancers. Computational techniques have played critical roles in identifying and characterizing allosteric ligand-binding sites on these proteins, and to screen ligand libraries against those sites. These efforts, combined with a wide range of biophysical, structural, biochemical and cell biological experiments, are beginning to yield promising inhibitors to treat malignancies associated with mutated Ras proteins. In this chapter, we discuss some of these developments and how the lessons learned from Ras might be applied to similar other challenging drug targets.
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21
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Lee KY, Fang Z, Enomoto M, Gasmi-Seabrook G, Zheng L, Koide S, Ikura M, Marshall CB. Two Distinct Structures of Membrane-Associated Homodimers of GTP- and GDP-Bound KRAS4B Revealed by Paramagnetic Relaxation Enhancement. Angew Chem Int Ed Engl 2020; 59:11037-11045. [PMID: 32227412 PMCID: PMC7395670 DOI: 10.1002/anie.202001758] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Indexed: 11/07/2022]
Abstract
KRAS homo-dimerization has been implicated in the activation of RAF kinases, however, the mechanism and structural basis remain elusive. We developed a system to study KRAS dimerization on nanodiscs using paramagnetic relaxation enhancement (PRE) NMR spectroscopy, and determined distinct structures of membrane-anchored KRAS dimers in the active GTP- and inactive GDP-loaded states. Both dimerize through an α4-α5 interface, but the relative orientation of the protomers and their contacts differ substantially. Dimerization of KRAS-GTP, stabilized by electrostatic interactions between R135 and E168, favors an orientation on the membrane that promotes accessibility of the effector-binding site. Remarkably, "cross"-dimerization between GTP- and GDP-bound KRAS molecules is unfavorable. These models provide a platform to elucidate the structural basis of RAF activation by RAS and to develop inhibitors that can disrupt the KRAS dimerization. The methodology is applicable to many other farnesylated small GTPases.
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Affiliation(s)
- Ki-Young Lee
- Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, M5G 1L7, Canada
| | - Zhenhao Fang
- Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, M5G 1L7, Canada
| | - Masahiro Enomoto
- Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, M5G 1L7, Canada
| | | | - Le Zheng
- Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, M5G 1L7, Canada
| | - Shohei Koide
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, and Perlmutter Cancer Center, New York University Langone Health, New York, NY, 10016, USA
| | - Mitsuhiko Ikura
- Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, M5G 1L7, Canada
| | - Christopher B Marshall
- Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, M5G 1L7, Canada
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22
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Lee K, Fang Z, Enomoto M, Gasmi‐Seabrook G, Zheng L, Koide S, Ikura M, Marshall CB. Two Distinct Structures of Membrane‐Associated Homodimers of GTP‐ and GDP‐Bound KRAS4B Revealed by Paramagnetic Relaxation Enhancement. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202001758] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Ki‐Young Lee
- Princess Margaret Cancer CentreUniversity Health Network Toronto Ontario M5G 1L7 Canada
| | - Zhenhao Fang
- Princess Margaret Cancer CentreUniversity Health Network Toronto Ontario M5G 1L7 Canada
| | - Masahiro Enomoto
- Princess Margaret Cancer CentreUniversity Health Network Toronto Ontario M5G 1L7 Canada
| | | | - Le Zheng
- Princess Margaret Cancer CentreUniversity Health Network Toronto Ontario M5G 1L7 Canada
| | - Shohei Koide
- Department of Biochemistry and Molecular PharmacologyNew York University School of Medicine, and Perlmutter Cancer CenterNew York University Langone Health New York NY 10016 USA
| | - Mitsuhiko Ikura
- Princess Margaret Cancer CentreUniversity Health Network Toronto Ontario M5G 1L7 Canada
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Ngo VA, Sarkar S, Neale C, Garcia AE. How Anionic Lipids Affect Spatiotemporal Properties of KRAS4B on Model Membranes. J Phys Chem B 2020; 124:5434-5453. [PMID: 32438809 DOI: 10.1021/acs.jpcb.0c02642] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
RAS proteins are small membrane-anchored GTPases that regulate key cellular signaling networks. It has been recently shown that different anionic lipid types can affect the spatiotemporal properties of RAS through dimerization/clustering and signaling fidelity. To understand the effects of anionic lipids on key spatiotemporal properties of RAS, we dissected 1 ms of data from all-atom molecular dynamics simulations for KRAS4B on two model anionic lipid membranes that have 30% of POPS mixed with neutral POPC and 8% of PIP2 mixed with POPC. We unveiled the orientation space of KRAS4B, whose kinetics were slower and more distinguishable on the membrane containing PIP2 than the membrane containing POPS. Particularly, the PIP2-mixed membrane can differentiate a third kinetic orientation state from the other two known orientation states. We observed that each orientation state may yield different binding modes with an RAF kinase, which is required for activating the MAPK/ERK signaling pathway. However, an overall occluded probability, for which RAF kinases cannot bind KRAS4B, remains unchanged on the two different membranes. We identified rare fast diffusion modes of KRAS4B that appear coupled with orientations exposed to cytosolic RAF. Particularly, on the membrane having PIP2, we found nonlinear correlations between the orientation states and the conformations of the cationic farnesylated hypervariable region, which acts as an anchor in the membrane. Using diffusion coefficients estimated from the all-atom simulations, we quantified the effect of PIP2 and POPS on the KRAS4B dimerization via Green's function reaction dynamics simulations, in which the averaged dimerization rate is 12.5% slower on PIP2-mixed membranes.
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Affiliation(s)
- Van A Ngo
- Center for Nonlinear Studies (CNLS), Los Alamos National Lab, Los Alamos, New Mexico 87545, United States
| | - Sumantra Sarkar
- Center for Nonlinear Studies (CNLS), Los Alamos National Lab, Los Alamos, New Mexico 87545, United States
| | - Chris Neale
- Theoretical Biology and Biophysics Group, T-6, Los Alamos National Lab, Los Alamos, New Mexico 87545, United States
| | - Angel E Garcia
- Center for Nonlinear Studies (CNLS), Los Alamos National Lab, Los Alamos, New Mexico 87545, United States
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24
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Großeholz R, Feldman-Salit A, Wanke F, Schulze S, Glöckner N, Kemmerling B, Harter K, Kummer U. Specifying the role of BAK1-interacting receptor-like kinase 3 in brassinosteroid signaling. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2020; 62:456-469. [PMID: 30912278 DOI: 10.1111/jipb.12803] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Accepted: 02/27/2019] [Indexed: 05/26/2023]
Abstract
Brassinosteroids (BR) are involved in the control of several developmental processes ranging from root elongation to senescence and adaptation to environmental cues. Thus, BR perception and signaling have to be precisely regulated. One regulator is BRI1-associated kinase 1 (BAK1)-interacting receptor-like kinase 3 (BIR3). In the absence of BR, BIR3 forms complexes with BR insensitive 1 (BRI1) and BAK1. However, the biophysical and energetic requirements for complex formation in the absence of the ligand have yet to be determined. Using computational modeling, we simulated the potential complexes between the cytoplasmic domains of BAK1, BRI1 and BIR3. Our calculations and experimental data confirm the interaction of BIR3 with BAK1 and BRI1, with the BAK1 BIR3 interaction clearly favored. Furthermore, we demonstrate that BIR3 and BRI1 share the same interaction site with BAK1. This suggests a competition between BIR3 and BRI1 for binding to BAK1, which results in preferential binding of BIR3 to BAK1 in the absence of the ligand thereby preventing the active participation of BAK1 in BR signaling. Our model also suggests that BAK1 and BRI1 can interact even while BAK1 is in complex with BIR3 at an additional binding site of BAK1 that does not allow active BR signaling.
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Affiliation(s)
- Ruth Großeholz
- Centre for Organismal Studies/ BioQuant, Heidelberg University, 69120, Heidelberg, Germany
| | - Anna Feldman-Salit
- Centre for Organismal Studies/ BioQuant, Heidelberg University, 69120, Heidelberg, Germany
| | - Friederike Wanke
- Center for Plant Molecular Biology (ZMBP), University Tübingen, 72076, Tübingen, Germany
| | - Sarina Schulze
- Center for Plant Molecular Biology (ZMBP), University Tübingen, 72076, Tübingen, Germany
| | - Nina Glöckner
- Center for Plant Molecular Biology (ZMBP), University Tübingen, 72076, Tübingen, Germany
| | - Birgit Kemmerling
- Center for Plant Molecular Biology (ZMBP), University Tübingen, 72076, Tübingen, Germany
| | - Klaus Harter
- Center for Plant Molecular Biology (ZMBP), University Tübingen, 72076, Tübingen, Germany
| | - Ursula Kummer
- Centre for Organismal Studies/ BioQuant, Heidelberg University, 69120, Heidelberg, Germany
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25
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Prakash P, Gorfe AA. Probing the Conformational and Energy Landscapes of KRAS Membrane Orientation. J Phys Chem B 2019; 123:8644-8652. [PMID: 31554397 DOI: 10.1021/acs.jpcb.9b05796] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Membrane reorientation of oncogenic RAS proteins is emerging as an important modulator of their functions. Previous studies have shown that the most common orientations include those with either the three C-terminal α-helices (OS1) or N-terminal β-strands (OS2) of the catalytic domain facing the membrane. OS1 and OS2 differ by the degree to which the effector-interacting surface is occluded by the membrane. However, the relative stability of these states and the rates of transition between them remained undetermined. How mutations might modulate preferences for specific orientation states is also far from clear. The current work attempted to address these questions through a comprehensive analysis of two 20 μs-long atomistic molecular dynamics simulations. The simulations were conducted on the oncogenic G12D and Q61H KRAS mutants bound to an anionic lipid bilayer. G12D and Q61H are among the most prevalent cancer-causing mutations at the P-loop and switch 2 regions of KRAS, respectively. We found that both mutants fluctuate in a similar manner between OS1 and OS2 via an intermediate orientation OS0, and both favor the signaling competent OS1 and OS0 over the occluded OS2. However, they differ in the details, such as in the extent to which they sample OS1. Analysis of the orientation free-energy landscapes estimated from the simulations indicate that OS1 and OS2 are the most stable states. However, the overall free energy surface is rugged, indicating a large diversity of conformations including at least two substates in each orientation state that differ in stability only by about 0.5-1.0 kcal/mol. Reversible transitions between OS1 and OS2 occur via two well-defined pathways that traverse OS0. In the minimum energy path, helix 4 remains close to the membrane as the angle of the catalytic domain from the membrane plane changes, resulting in a barrier of ∼1 kcal/mol for OS1/OS2 interconversions. Estimation of the rates of the various transitions based on survival probabilities yielded two rate constants in the order of 107 and 106 s-1, which we attribute to intrinsic protein conformational dynamics and transient protein-lipid interactions, respectively. The faster process dominates every transition, confirming a previous suggestion that RAS membrane reorientation is driven by conformational fluctuations rather than protein-lipid interactions.
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Affiliation(s)
- Priyanka Prakash
- McGovern Medical School , University of Texas Health Science Center at Houston , Department of Integrative Biology and Pharmacology , 6431 Fannin Street , Houston , Texas 77030 , United States
| | - Alemayehu A Gorfe
- McGovern Medical School , University of Texas Health Science Center at Houston , Department of Integrative Biology and Pharmacology , 6431 Fannin Street , Houston , Texas 77030 , United States.,MD Anderson Cancer Center , UTHealth Graduate School of Biomedical Sciences , 6431 Fannin Street , Houston , Texas 77030 , United States
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26
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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: 32] [Impact Index Per Article: 6.4] [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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Adeniji EA, Olotu FA, Soliman MES. Exploring the Lapse in Druggability: Sequence Analysis, Structural Dynamics and Binding Site Characterization of K-RasG12C Variant, a Feasible Oncotherapeutics Target. Anticancer Agents Med Chem 2019; 18:1540-1550. [PMID: 30019652 DOI: 10.2174/1871520618666180718110231] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Revised: 01/28/2018] [Accepted: 07/04/2018] [Indexed: 12/24/2022]
Abstract
BACKGROUND The difficulty in druggability of K-Ras variant has presented a challenge in the treatment of cancer diseases associated with its dysfunctionality. Despite the identification of different binding sites, limited information exists in the literature about their characteristics. Therefore, identification, crossvalidation and characterization of its druggable sites would aid the design of chemical compounds that will arrest its dysfunctionality related oncogenesis. OBJECTIVE This study entails the identification, cross-validation and characterization of K-Ras G12C variant's binding sites for potential druggability, coupled with the elucidation of alterations in 3D conformations and dynamics. METHOD Molecular dynamics simulation was carried out on the inactive, the active and the hyperactive K-RasG12Cvariant using the amber software package. The SiteMap software was employed in identifying and characterizing the druggable binding sites while the validation of the binding sites was carried out with the SiteHound and MetaPocket servers. RESULTS Four druggable binding sites were identified, validated and characterized based on physicochemical attributes such as size, volume, degree of enclosure or exposure, degree of contact, hydrophobic/hydrophilic character, hydrophobic/hydrophilic balance and hydrogen-bonding features. Conformational studies also revealed that the K-Ras variant exhibited notable structural instability, increased flexibility and a strongly anticorrelated movement compared to the inactive and active wildtype forms. CONCLUSION The attributes of the characterized druggable sites will be useful in designing site-specific K-Ras inhibitors for the treatment of K-Ras variant associated cancer diseases.
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Affiliation(s)
- Emmanuel A Adeniji
- Molecular Bio-Computation and Drug Design Laboratory, School of Health Sciences, University of KwaZulu-Natal, Westville Campus, Durban 4001, South Africa
| | - Fisayo A Olotu
- Molecular Bio-Computation and Drug Design Laboratory, School of Health Sciences, University of KwaZulu-Natal, Westville Campus, Durban 4001, South Africa
| | - Mahmoud E S Soliman
- Molecular Bio-Computation and Drug Design Laboratory, School of Health Sciences, University of KwaZulu-Natal, Westville Campus, Durban 4001, South Africa
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28
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Mamode Cassim A, Gouguet P, Gronnier J, Laurent N, Germain V, Grison M, Boutté Y, Gerbeau-Pissot P, Simon-Plas F, Mongrand S. Plant lipids: Key players of plasma membrane organization and function. Prog Lipid Res 2018; 73:1-27. [PMID: 30465788 DOI: 10.1016/j.plipres.2018.11.002] [Citation(s) in RCA: 124] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 11/07/2018] [Accepted: 11/09/2018] [Indexed: 12/29/2022]
Abstract
The plasma membrane (PM) is the biological membrane that separates the interior of all cells from the outside. The PM is constituted of a huge diversity of proteins and lipids. In this review, we will update the diversity of molecular species of lipids found in plant PM. We will further discuss how lipids govern global properties of the plant PM, explaining that plant lipids are unevenly distributed and are able to organize PM in domains. From that observation, it emerges a complex picture showing a spatial and multiscale segregation of PM components. Finally, we will discuss how lipids are key players in the function of PM in plants, with a particular focus on plant-microbe interaction, transport and hormone signaling, abiotic stress responses, plasmodesmata function. The last chapter is dedicated to the methods that the plant membrane biology community needs to develop to get a comprehensive understanding of membrane organization in plants.
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Affiliation(s)
- Adiilah Mamode Cassim
- Laboratoire de Biogenèse Membranaire (LBM), CNRS, University of Bordeaux, UMR 5200, F-33882 Villenave d'Ornon, France
| | - Paul Gouguet
- Laboratoire de Biogenèse Membranaire (LBM), CNRS, University of Bordeaux, UMR 5200, F-33882 Villenave d'Ornon, France
| | - Julien Gronnier
- Laboratoire de Biogenèse Membranaire (LBM), CNRS, University of Bordeaux, UMR 5200, F-33882 Villenave d'Ornon, France
| | - Nelson Laurent
- Agroécologie, AgroSup Dijon, INRA, University of Bourgogne Franche-Comté, F-21000 Dijon, ERL 6003 CNRS, Dijon, France
| | - Véronique Germain
- Laboratoire de Biogenèse Membranaire (LBM), CNRS, University of Bordeaux, UMR 5200, F-33882 Villenave d'Ornon, France
| | - Magali Grison
- Laboratoire de Biogenèse Membranaire (LBM), CNRS, University of Bordeaux, UMR 5200, F-33882 Villenave d'Ornon, France
| | - Yohann Boutté
- Laboratoire de Biogenèse Membranaire (LBM), CNRS, University of Bordeaux, UMR 5200, F-33882 Villenave d'Ornon, France
| | - Patricia Gerbeau-Pissot
- Agroécologie, AgroSup Dijon, INRA, University of Bourgogne Franche-Comté, F-21000 Dijon, ERL 6003 CNRS, Dijon, France
| | - Françoise Simon-Plas
- Agroécologie, AgroSup Dijon, INRA, University of Bourgogne Franche-Comté, F-21000 Dijon, ERL 6003 CNRS, Dijon, France.
| | - Sébastien Mongrand
- Laboratoire de Biogenèse Membranaire (LBM), CNRS, University of Bordeaux, UMR 5200, F-33882 Villenave d'Ornon, France.
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29
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Garrido E, Lázaro J, Jaumot M, Agell N, Rubio-Martinez J. Modeling and subtleties of K-Ras and Calmodulin interaction. PLoS Comput Biol 2018; 14:e1006552. [PMID: 30376570 PMCID: PMC6226203 DOI: 10.1371/journal.pcbi.1006552] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Revised: 11/09/2018] [Accepted: 10/08/2018] [Indexed: 12/12/2022] Open
Abstract
K-Ras, one of the most common small GTPases of the cell, still presents many riddles, despite the intense efforts to unveil its mysteries. Such is the case of its interaction with Calmodulin, a small acidic protein known for its role as a calcium ion sensor. Although the interaction between these two proteins and its biological implications have been widely studied, a model of their interaction has not been performed. In the present work we analyse this intriguing interaction by computational means. To do so, both conventional molecular dynamics and scaled molecular dynamics have been used. Our simulations suggest a model in which Calmodulin would interact with both the hypervariable region and the globular domain of K-Ras, using a lobe to interact with each of them. According to the presented model, the interface of helixes α4 and α5 of the globular domain of K-Ras would be relevant for the interaction with a lobe of Calmodulin. These results were also obtained when bringing the proteins together in a step wise manner with the umbrella sampling methodology. The computational results have been validated using SPR to determine the relevance of certain residues. Our results demonstrate that, when mutating residues of the α4-α5 interface described to be relevant for the interaction with Calmodulin, the interaction of the globular domain of K-Ras with Calmodulin diminishes. However, it is to be considered that our simulations indicate that the bulk of the interaction would fall on the hypervariable region of K-Ras, as many more interactions are identified in said region. All in all our simulations present a suitable model in which K-Ras could interact with Calmodulin at membrane level using both its globular domain and its hypervariable region to stablish an interaction that leads to an altered signalling. K-Ras is one of the most mutated oncogenes in human cancer. Although several studies validate K-Ras protein as good candidate for direct therapeutic targeting, pharmacologic targeting has not been successful. During the last years increasing evidences demonstrate that oncogenic K-Ras activity can be modulated in vivo by dimerization, nanoclustering at the plasma membrane or interaction with non-effector proteins, consequently opening new therapeutic strategies. We have previously demonstrated that Calmodulin, an ubiquitous Ca2+-binding protein, is one of this K-Ras interacting proteins and that it negatively modulates K-Ras signaling. Although experimental data were available showing the relevant regions for this interaction, a model of K-Ras and Calmodulin interaction was missing. In the present work by using different computational modeling techniques we obtained a model for this interaction that agrees with the experimental data. We believe the present model will help to better understand K-Ras regulation, and to design new inhibitors. For instance, base on our model, we can predict that the interaction can take place at the plasma membrane, and that since the surface of K-Ras that interact with Calmodulin is the same that it uses for dimerization, that Calmodulin could be inhibiting K-Ras dimerization.
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Affiliation(s)
- Eduardo Garrido
- Department of Materials Science and Physical Chemistry, Universitat de Barcelona, Institut de Recerca en Química Teòrica i Computacional (IQTCUB), Barcelona, Spain
- Department de Biomedicina, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, IDIBAPS, Barcelona, Spain
| | - Juan Lázaro
- Department de Biomedicina, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, IDIBAPS, Barcelona, Spain
| | - Montserrat Jaumot
- Department de Biomedicina, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, IDIBAPS, Barcelona, Spain
| | - Neus Agell
- Department de Biomedicina, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, IDIBAPS, Barcelona, Spain
- * E-mail: (NA); (JRM)
| | - Jaime Rubio-Martinez
- Department of Materials Science and Physical Chemistry, Universitat de Barcelona, Institut de Recerca en Química Teòrica i Computacional (IQTCUB), Barcelona, Spain
- * E-mail: (NA); (JRM)
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30
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Zhou Y, Prakash P, Gorfe AA, Hancock JF. Ras and the Plasma Membrane: A Complicated Relationship. Cold Spring Harb Perspect Med 2018; 8:cshperspect.a031831. [PMID: 29229665 DOI: 10.1101/cshperspect.a031831] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The primary site of Ras signal transduction is the plasma membrane (PM). On the PM, the ubiquitously expressed Ras isoforms, H-, N-, and K-Ras, spatially segregate to nonoverlapping nanometer-sized domains, called nanoclusters, with further lateral segregation into nonoverlapping guanosine triphosphate (GTP)-bound and guanosine diphosphate (GDP)-bound nanoclusters. Effector binding and activation is restricted to GTP nanoclusters, rendering the underlying assembly mechanism essential to Ras signaling. Ras nanoclusters have distinct lipid compositions as a result of lipid-sorting specificity encoded in each Ras carboxy-terminal membrane anchor. The role of the G-domain in regulating anchor-membrane interactions is becoming clearer. Ras G-domains undergo significant conformational orientation changes on guanine nucleotide switch, leading to differential direct contacts between the G-domain and reorganization of the membrane anchor. Ras G-domains also contain weak dimer interfaces, resulting in homodimerization, which is an obligate step of nanoclustering. Modulating the formation of Ras dimers, the lipid composition of the PM or lateral dynamics of key PM phospholipids represent novel mechanisms whereby the extent of Ras nanoclustering can be regulated to tune the gain in Ras signaling circuits.
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Affiliation(s)
- Yong Zhou
- 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
| | - John F Hancock
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston, Houston, Texas 77030
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31
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Chung JK, Lee YK, Denson JP, Gillette WK, Alvarez S, Stephen AG, Groves JT. K-Ras4B Remains Monomeric on Membranes over a Wide Range of Surface Densities and Lipid Compositions. Biophys J 2018; 114:137-145. [PMID: 29320680 PMCID: PMC5984903 DOI: 10.1016/j.bpj.2017.10.042] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Revised: 09/22/2017] [Accepted: 10/30/2017] [Indexed: 11/23/2022] Open
Abstract
Ras is a membrane-anchored signaling protein that serves as a hub for many signaling pathways and also plays a prominent role in cancer. The intrinsic behavior of Ras on the membrane has captivated the biophysics community in recent years, especially the possibility that it may form dimers. In this article, we describe results from a comprehensive series of experiments using fluorescence correlation spectroscopy and single-molecule tracking to probe the possible dimerization of natively expressed and fully processed K-Ras4B in supported lipid bilayer membranes. Key to these studies is the fact that K-Ras4B has its native membrane anchor, including both the farnesylation and methylation of the terminal cysteine, enabling detailed exploration of possible effects of cholesterol and lipid composition on K-Ras4B membrane organization. The results from all conditions studied indicate that full-length K-Ras4B lacks intrinsic dimerization capability. This suggests that any lateral organization of Ras in living cell membranes likely stems from interactions with other factors.
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Affiliation(s)
- Jean K Chung
- Department of Chemistry, University of California Berkeley, Berkeley, California
| | - Young Kwang Lee
- Department of Chemistry, University of California Berkeley, Berkeley, California
| | - John-Paul Denson
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc., Frederick, Maryland
| | - William K Gillette
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc., Frederick, Maryland
| | - Steven Alvarez
- Department of Materials Science and Engineering, University of California Berkeley, Berkeley, California
| | - Andrew G Stephen
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc., Frederick, Maryland
| | - Jay T Groves
- Department of Chemistry, University of California Berkeley, Berkeley, California.
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32
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Atsmon-Raz Y, Tieleman DP. Parameterization of Palmitoylated Cysteine, Farnesylated Cysteine, Geranylgeranylated Cysteine, and Myristoylated Glycine for the Martini Force Field. J Phys Chem B 2017; 121:11132-11143. [PMID: 29144135 DOI: 10.1021/acs.jpcb.7b10175] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Peripheral membrane proteins go through various post-translational modifications that covalently bind fatty acid tails to specific amino acids. These post-translational modifications significantly alter the lipophilicity of the modified proteins and allow them to anchor to biological membranes. Over 1000 different proteins have been identified to date that require such membrane-protein interactions to carry out their biological functions, including members of the Src and Ras superfamilies that play key roles in cell signaling and carcinogenesis. We have used all-atom simulations with the CHARMM36 force field to parameterize four of the most common post-translational modifications for the Martini 2.2 force field: palmitoylated cysteine, farnesylated cysteine, geranylgeranylated cysteine, and myristoylated glycine. The parameters reproduce the key features of clusters of configurations of the different anchors in lipid membranes as well as the water-octanol partitioning free energies of the anchors, which are crucial for the correct reproduction of the expected biophysical behavior of peripheral membrane proteins at the membrane-water interface. Implementation in existing Martini setup tools facilitates the use of the new parameters.
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Affiliation(s)
- Yoav Atsmon-Raz
- Department of Biological Sciences, Centre for Molecular Simulation, University of Calgary , 2500 University Drive NW, Calgary, Alberta, Canada T2N 1N4
| | - D Peter Tieleman
- Department of Biological Sciences, Centre for Molecular Simulation, University of Calgary , 2500 University Drive NW, Calgary, Alberta, Canada T2N 1N4
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33
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Molecular Dynamics Simulations and Dynamic Network Analysis Reveal the Allosteric Unbinding of Monobody to H-Ras Triggered by R135K Mutation. Int J Mol Sci 2017; 18:ijms18112249. [PMID: 29072601 PMCID: PMC5713219 DOI: 10.3390/ijms18112249] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Revised: 10/13/2017] [Accepted: 10/24/2017] [Indexed: 12/12/2022] Open
Abstract
Ras proteins, as small GTPases, mediate cell proliferation, survival and differentiation. Ras mutations have been associated with a broad spectrum of human cancers and thus targeting Ras represents a potential way forward for cancer therapy. A recently reported monobody NS1 allosterically disrupts the Ras-mediated signaling pathway, but its efficacy is reduced by R135K mutation in H-Ras. However, the detailed mechanism is unresolved. Here, using molecular dynamics (MD) simulations and dynamic network analysis, we explored the molecular mechanism for the unbinding of NS1 to H-Ras and shed light on the underlying allosteric network in H-Ras. MD simulations revealed that the overall structures of the two complexes did not change significantly, but the H-Ras–NS1 interface underwent significant conformational alteration in the mutant Binding free energy analysis showed that NS1 binding was unfavored after R135K mutation, which resulted in the unfavorable binding of NS1. Furthermore, the critical residues on H-Ras responsible for the loss of binding of NS1 were identified. Importantly, the allosteric networks for these important residues were revealed, which yielded a novel insight into the allosteric regulatory mechanism of H-Ras.
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34
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Vetter IR. Interface analysis of small GTP binding protein complexes suggests preferred membrane orientations. Biol Chem 2017; 398:637-651. [PMID: 28002022 DOI: 10.1515/hsz-2016-0287] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Accepted: 12/12/2016] [Indexed: 11/15/2022]
Abstract
Crystal structures of small GTP binding protein complexes with their effectors and regulators reveal that one particularly flat side of the G domain that contains helix α4 and the C-terminal helix α5 is practically devoid of contacts. Although this observation seems trivial as the main binding targets are the switch I and II regions opposite of this side, the fact that all interacting proteins, even the largest ones, seem to avoid occupying this area (except for Ran, that does not localize to membranes) is very striking. An orientation with this 'flat' side parallel to the membrane was proposed before and would allow simultaneous interaction of the lipidated C-terminus and positive charges in the α4 helix with the membrane while being bound to effector or regulator molecules. Furthermore, this 'flat' side might be involved in regulatory mechanisms: a Ras dimer that is found in different crystal forms interacts exactly at this side. Additional interface analysis of GTPase complexes nicely confirms the effect of different flexibilities of the GTP and GDP forms. Besides Ran proteins, guanine nucleotide exchange factors (GEFs) bury the largest surface areas to provide the binding energy to open up the switch regions for nucleotide exchange.
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Affiliation(s)
- Ingrid R Vetter
- Max Planck Institute of Molecular Physiology, Department of Mechanistic Cell Biology, Otto-Hahn-Str. 11, D-44227 Dortmund
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Gerwert K, Mann D, Kötting C. Common mechanisms of catalysis in small and heterotrimeric GTPases and their respective GAPs. Biol Chem 2017; 398:523-533. [PMID: 28245182 DOI: 10.1515/hsz-2016-0314] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Accepted: 02/15/2017] [Indexed: 01/15/2023]
Abstract
GTPases are central switches in cells. Their dysfunctions are involved in severe diseases. The small GTPase Ras regulates cell growth, differentiation and apoptosis by transmitting external signals to the nucleus. In one group of oncogenic mutations, the 'switch-off' reaction is inhibited, leading to persistent activation of the signaling pathway. The switch reaction is regulated by GTPase-activating proteins (GAPs), which catalyze GTP hydrolysis in Ras, and by guanine nucleotide exchange factors, which catalyze the exchange of GDP for GTP. Heterotrimeric G-proteins are activated by G-protein coupled receptors and are inactivated by GTP hydrolysis in the Gα subunit. Their GAPs are called regulators of G-protein signaling. In the same way that Ras serves as a prototype for small GTPases, Gαi1 is the most well-studied Gα subunit. By utilizing X-ray structural models, time-resolved infrared-difference spectroscopy, and biomolecular simulations, we elucidated the detailed molecular reaction mechanism of the GTP hydrolysis in Ras and Gαi1. In both proteins, the charge distribution of GTP is driven towards the transition state, and an arginine is precisely positioned to facilitate nucleophilic attack of water. In addition to these mechanistic details of GTP hydrolysis, Ras dimerization as an emerging factor in signal transduction is discussed in this review.
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Affiliation(s)
- Klaus Gerwert
- Department of Biophysics, Ruhr-University Bochum, Universitätsstrasse 150, D-44801 Bochum
| | - Daniel Mann
- Department of Biophysics, Ruhr-University Bochum, Universitätsstrasse 150, D-44801 Bochum
| | - Carsten Kötting
- Department of Biophysics, Ruhr-University Bochum, Universitätsstrasse 150, D-44801 Bochum
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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: 41] [Impact Index Per Article: 5.9] [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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Sayyed-Ahmad A, Gorfe AA. Mixed-Probe Simulation and Probe-Derived Surface Topography Map Analysis for Ligand Binding Site Identification. J Chem Theory Comput 2017; 13:1851-1861. [PMID: 28252958 DOI: 10.1021/acs.jctc.7b00130] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Membrane proteins represent a considerable fraction of pharmaceutical drug targets. A computational technique to identify ligand binding pockets in these proteins is therefore of great importance. We recently reported such a technique called pMD-membrane that utilizes small molecule probes to detect ligand binding sites and surface hotspots on membrane proteins based on probe-based molecular dynamics simulation. The current work extends pMD-membrane to a diverse set of small organic molecular species that can be used as cosolvents during simulation of membrane proteins. We also describe a projection technique for globally quantifying probe densities on the protein surface and introduce a technique to construct surface topography maps directly from the probe-binding propensity of surface residues. The map reveals surface patterns and geometric features that aid in filtering out high probe density hotspots lacking pocketlike characteristics. We demonstrate the applicability of the extended pMD-membrane and the new analysis tool by exploring the druggability of full-length G12D, G12V, and G13D oncogenic K-Ras mutants bound to a negatively charged lipid bilayer. Using data from 30 pMD-membrane runs conducted in the presence of a 2.8 M cosolvent made up of an equal proportion of seven small organic molecules, we show that our approach robustly identifies known allosteric ligand binding sites and other reactive regions on K-Ras. Our results also show that accessibility of some pockets is modulated by differential membrane interactions.
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Affiliation(s)
- Abdallah Sayyed-Ahmad
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston , 6431 Fannin Street, Houston, Texas 77030, United States
| | - Alemayehu A 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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Computational and biochemical characterization of two partially overlapping interfaces and multiple weak-affinity K-Ras dimers. Sci Rep 2017; 7:40109. [PMID: 28067274 PMCID: PMC5220301 DOI: 10.1038/srep40109] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Accepted: 12/01/2016] [Indexed: 02/02/2023] Open
Abstract
Recent studies found that membrane-bound K-Ras dimers are important for biological function. However, the structure and thermodynamic stability of these complexes remained unknown because they are hard to probe by conventional approaches. Combining data from a wide range of computational and experimental approaches, here we describe the structure, dynamics, energetics and mechanism of assembly of multiple K-Ras dimers. Utilizing a range of techniques for the detection of reactive surfaces, protein-protein docking and molecular simulations, we found that two largely polar and partially overlapping surfaces underlie the formation of multiple K-Ras dimers. For validation we used mutagenesis, electron microscopy and biochemical assays under non-denaturing conditions. We show that partial disruption of a predicted interface through charge reversal mutation of apposed residues reduces oligomerization while introduction of cysteines at these positions enhanced dimerization likely through the formation of an intermolecular disulfide bond. Free energy calculations indicated that K-Ras dimerization involves direct but weak protein-protein interactions in solution, consistent with the notion that dimerization is facilitated by membrane binding. Taken together, our atomically detailed analyses provide unique mechanistic insights into K-Ras dimer formation and membrane organization as well as the conformational fluctuations and equilibrium thermodynamics underlying these processes.
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RASSF5: An MST activator and tumor suppressor in vivo but opposite in vitro. Curr Opin Struct Biol 2016; 41:217-224. [DOI: 10.1016/j.sbi.2016.09.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Accepted: 09/01/2016] [Indexed: 01/05/2023]
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Lu S, Jang H, Gu S, Zhang J, Nussinov R. Drugging Ras GTPase: a comprehensive mechanistic and signaling structural view. Chem Soc Rev 2016; 45:4929-52. [PMID: 27396271 PMCID: PMC5021603 DOI: 10.1039/c5cs00911a] [Citation(s) in RCA: 142] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Ras proteins are small GTPases, cycling between inactive GDP-bound and active GTP-bound states. Through these switches they regulate signaling that controls cell growth and proliferation. Activating Ras mutations are associated with approximately 30% of human cancers, which are frequently resistant to standard therapies. Over the past few years, structural biology and in silico drug design, coupled with improved screening technology, led to a handful of promising inhibitors, raising the possibility of drugging Ras proteins. At the same time, the invariable emergence of drug resistance argues for the critical importance of additionally honing in on signaling pathways which are likely to be involved. Here we overview current advances in Ras structural knowledge, including the conformational dynamic of full-length Ras in solution and at the membrane, therapeutic inhibition of Ras activity by targeting its active site, allosteric sites, and Ras-effector protein-protein interfaces, Ras dimers, the K-Ras4B/calmodulin/PI3Kα trimer, and targeting Ras with siRNA. To mitigate drug resistance, we propose signaling pathways that can be co-targeted along with Ras and explain why. These include pathways leading to the expression (or activation) of YAP1 and c-Myc. We postulate that these and Ras signaling pathways, MAPK/ERK and PI3K/Akt/mTOR, act independently and in corresponding ways in cell cycle control. The structural data are instrumental in the discovery and development of Ras inhibitors for treating RAS-driven cancers. Together with the signaling blueprints through which drug resistance can evolve, this review provides a comprehensive and innovative master plan for tackling mutant Ras proteins.
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Affiliation(s)
- Shaoyong Lu
- Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Children’s Medical Center, Shanghai Jiao Tong University, School of Medicine, Shanghai, 200127, China
| | - Hyunbum Jang
- Cancer and Inflammation Program, Leidos Biomedical Research, Inc., Frederick National Laboratory, National Cancer Institute, Frederick, MD 21702, U.S.A
| | - Shuo Gu
- Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Children’s Medical Center, Shanghai Jiao Tong University, School of Medicine, Shanghai, 200127, China
| | - Jian Zhang
- Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Children’s Medical Center, Shanghai Jiao Tong University, School of Medicine, Shanghai, 200127, China
| | - Ruth Nussinov
- Cancer and Inflammation Program, Leidos Biomedical Research, Inc., Frederick National Laboratory, National Cancer Institute, Frederick, MD 21702, U.S.A
- Department of Human Genetics and Molecular Medicine, Sackler School of Medicine, Sackler Institute of Molecular Medicine, Tel Aviv University, Tel Aviv 69978, Israel
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Abstract
Lipid-modified GTPases in the Ras superfamily that mediate a variety of cell signaling processes were thought to be passively anchored to membranes. However, an increasing number of recent studies are finding that membrane binding of these proteins is hardly a passive process, and it involves the soluble catalytic domain as well as the lipid anchor. The catalytic domain adopts multiple orientations on the membrane surface due to internal fluctuations that are modulated by activation status and mutations. Distinct orientation preferences among small GTPases likely lead to differential signaling outcomes, as downstream effectors can sense different orientations. We review recent studies behind this important conclusion.
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Affiliation(s)
- Priyanka Prakash
- a Department of Integrative Biology and Pharmacology , University of Texas Health Science Center at Houston , Houston , TX , USA
| | - Alemayehu A Gorfe
- a Department of Integrative Biology and Pharmacology , University of Texas Health Science Center at Houston , Houston , TX , USA
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