1
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Nguyen K, López CA, Neale C, Van QN, Carpenter TS, Di Natale F, Travers T, Tran TH, Chan AH, Bhatia H, Frank PH, Tonelli M, Zhang X, Gulten G, Reddy T, Burns V, Oppelstrup T, Hengartner N, Simanshu DK, Bremer PT, Chen D, Glosli JN, Shrestha R, Turbyville T, Streitz FH, Nissley DV, Ingólfsson HI, Stephen AG, Lightstone FC, Gnanakaran S. Exploring CRD mobility during RAS/RAF engagement at the membrane. Biophys J 2022; 121:3630-3650. [PMID: 35778842 PMCID: PMC9617161 DOI: 10.1016/j.bpj.2022.06.035] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 06/21/2022] [Accepted: 06/28/2022] [Indexed: 11/25/2022] Open
Abstract
During the activation of mitogen-activated protein kinase (MAPK) signaling, the RAS-binding domain (RBD) and cysteine-rich domain (CRD) of RAF bind to active RAS at the plasma membrane. The orientation of RAS at the membrane may be critical for formation of the RAS-RBDCRD complex and subsequent signaling. To explore how RAS membrane orientation relates to the protein dynamics within the RAS-RBDCRD complex, we perform multiscale coarse-grained and all-atom molecular dynamics (MD) simulations of KRAS4b bound to the RBD and CRD domains of RAF-1, both in solution and anchored to a model plasma membrane. Solution MD simulations describe dynamic KRAS4b-CRD conformations, suggesting that the CRD has sufficient flexibility in this environment to substantially change its binding interface with KRAS4b. In contrast, when the ternary complex is anchored to the membrane, the mobility of the CRD relative to KRAS4b is restricted, resulting in fewer distinct KRAS4b-CRD conformations. These simulations implicate membrane orientations of the ternary complex that are consistent with NMR measurements. While a crystal structure-like conformation is observed in both solution and membrane simulations, a particular intermolecular rearrangement of the ternary complex is observed only when it is anchored to the membrane. This configuration emerges when the CRD hydrophobic loops are inserted into the membrane and helices α3-5 of KRAS4b are solvent exposed. This membrane-specific configuration is stabilized by KRAS4b-CRD contacts that are not observed in the crystal structure. These results suggest modulatory interplay between the CRD and plasma membrane that correlate with RAS/RAF complex structure and dynamics, and potentially influence subsequent steps in the activation of MAPK signaling.
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Affiliation(s)
- Kien Nguyen
- Theoretical Biology and Biophysics Group, Los Alamos National Laboratory, Los Alamos, New Mexico
| | - Cesar A López
- Theoretical Biology and Biophysics Group, Los Alamos National Laboratory, Los Alamos, New Mexico
| | - Chris Neale
- Theoretical Biology and Biophysics Group, Los Alamos National Laboratory, Los Alamos, New Mexico
| | - Que N Van
- National Cancer Institute RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, Maryland
| | - Timothy S Carpenter
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California
| | - Francesco Di Natale
- Applications, Simulations, and Quality, Lawrence Livermore National Laboratory, Livermore, California
| | | | - Timothy H Tran
- National Cancer Institute RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, Maryland
| | - Albert H Chan
- National Cancer Institute RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, Maryland
| | - Harsh Bhatia
- Center for Applied Scientific Computing, Lawrence Livermore National Laboratory, Livermore, California
| | - Peter H Frank
- National Cancer Institute RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, Maryland
| | - Marco Tonelli
- National Magnetic Resonance Facility at Madison, Biochemistry Department, University of Wisconsin-Madison, Madison, Wisconsin
| | - Xiaohua Zhang
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California
| | - Gulcin Gulten
- National Cancer Institute RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, Maryland
| | - Tyler Reddy
- CCS-7, Los Alamos National Laboratory, Los Alamos, New Mexico
| | - Violetta Burns
- Theoretical Biology and Biophysics Group, Los Alamos National Laboratory, Los Alamos, New Mexico
| | - Tomas Oppelstrup
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California
| | - Nick Hengartner
- Theoretical Biology and Biophysics Group, Los Alamos National Laboratory, Los Alamos, New Mexico
| | - Dhirendra K Simanshu
- National Cancer Institute RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, Maryland
| | - Peer-Timo Bremer
- Center for Applied Scientific Computing, Lawrence Livermore National Laboratory, Livermore, California
| | - De Chen
- National Cancer Institute RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, Maryland
| | - James N Glosli
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California
| | - Rebika Shrestha
- National Cancer Institute RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, Maryland
| | - Thomas Turbyville
- National Cancer Institute RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, Maryland
| | - Frederick H Streitz
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California
| | - Dwight V Nissley
- National Cancer Institute RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, Maryland
| | - Helgi I Ingólfsson
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California
| | - Andrew G Stephen
- National Cancer Institute RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, Maryland
| | - Felice C Lightstone
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California
| | - Sandrasegaram Gnanakaran
- Theoretical Biology and Biophysics Group, Los Alamos National Laboratory, Los Alamos, New Mexico.
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2
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Nussinov R, Zhang M, Maloney R, Liu Y, Tsai CJ, Jang H. Allostery: Allosteric Cancer Drivers and Innovative Allosteric Drugs. J Mol Biol 2022; 434:167569. [PMID: 35378118 PMCID: PMC9398924 DOI: 10.1016/j.jmb.2022.167569] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 03/11/2022] [Accepted: 03/25/2022] [Indexed: 01/12/2023]
Abstract
Here, we discuss the principles of allosteric activating mutations, propagation downstream of the signals that they prompt, and allosteric drugs, with examples from the Ras signaling network. We focus on Abl kinase where mutations shift the landscape toward the active, imatinib binding-incompetent conformation, likely resulting in the high affinity ATP outcompeting drug binding. Recent pharmacological innovation extends to allosteric inhibitor (GNF-5)-linked PROTAC, targeting Bcr-Abl1 myristoylation site, and broadly, allosteric heterobifunctional degraders that destroy targets, rather than inhibiting them. Designed chemical linkers in bifunctional degraders can connect the allosteric ligand that binds the target protein and the E3 ubiquitin ligase warhead anchor. The physical properties and favored conformational state of the engineered linker can precisely coordinate the distance and orientation between the target and the recruited E3. Allosteric PROTACs, noncompetitive molecular glues, and bitopic ligands, with covalent links of allosteric ligands and orthosteric warheads, increase the effective local concentration of productively oriented and placed ligands. Through covalent chemical or peptide linkers, allosteric drugs can collaborate with competitive drugs, degrader anchors, or other molecules of choice, driving innovative drug discovery.
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Affiliation(s)
- Ruth Nussinov
- Computational Structural Biology Section, Frederick National Laboratory for Cancer Research in the Laboratory of Cancer Immunometabolism, National Cancer Institute, Frederick, MD 21702, USA; Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel.
| | - Mingzhen Zhang
- Computational Structural Biology Section, Frederick National Laboratory for Cancer Research in the Laboratory of Cancer Immunometabolism, National Cancer Institute, Frederick, MD 21702, USA
| | - Ryan Maloney
- Computational Structural Biology Section, Frederick National Laboratory for Cancer Research in the Laboratory of Cancer Immunometabolism, National Cancer Institute, Frederick, MD 21702, USA
| | - Yonglan Liu
- Computational Structural Biology Section, Frederick National Laboratory for Cancer Research in the Laboratory of Cancer Immunometabolism, National Cancer Institute, Frederick, MD 21702, USA
| | - Chung-Jung Tsai
- Computational Structural Biology Section, Frederick National Laboratory for Cancer Research in the Laboratory of Cancer Immunometabolism, National Cancer Institute, Frederick, MD 21702, USA
| | - Hyunbum Jang
- Computational Structural Biology Section, Frederick National Laboratory for Cancer Research in the Laboratory of Cancer Immunometabolism, National Cancer Institute, Frederick, MD 21702, USA
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3
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Nussinov R, Tsai CJ, Jang H. Allostery, and how to define and measure signal transduction. Biophys Chem 2022; 283:106766. [PMID: 35121384 PMCID: PMC8898294 DOI: 10.1016/j.bpc.2022.106766] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 01/21/2022] [Accepted: 01/24/2022] [Indexed: 12/15/2022]
Abstract
Here we ask: What is productive signaling? How to define it, how to measure it, and most of all, what are the parameters that determine it? Further, what determines the strength of signaling from an upstream to a downstream node in a specific cell? These questions have either not been considered or not entirely resolved. The requirements for the signal to propagate downstream to activate (repress) transcription have not been considered either. Yet, the questions are pivotal to clarify, especially in diseases such as cancer where determination of signal propagation can point to cell proliferation and to emerging drug resistance, and to neurodevelopmental disorders, such as RASopathy, autism, attention-deficit/hyperactivity disorder (ADHD), and cerebral palsy. Here we propose a framework for signal transduction from an upstream to a downstream node addressing these questions. Defining cellular processes, experimentally measuring them, and devising powerful computational AI-powered algorithms that exploit the measurements, are essential for quantitative science.
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Affiliation(s)
- Ruth Nussinov
- Computational Structural Biology Section, Frederick National Laboratory for Cancer Research in the Laboratory of Cancer Immunometabolism, National Cancer Institute, Frederick, MD 21702, USA; Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel.
| | - Chung-Jung Tsai
- Computational Structural Biology Section, Frederick National Laboratory for Cancer Research in the Laboratory of Cancer Immunometabolism, National Cancer Institute, Frederick, MD 21702, USA
| | - Hyunbum Jang
- Computational Structural Biology Section, Frederick National Laboratory for Cancer Research in the Laboratory of Cancer Immunometabolism, National Cancer Institute, Frederick, MD 21702, USA
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4
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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:genes13020219. [PMID: 35205266 PMCID: PMC8872464 DOI: 10.3390/genes13020219] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [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;
- Correspondence:
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5
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Nussinov R, Zhang M, Maloney R, Tsai CJ, Yavuz BR, Tuncbag N, Jang H. Mechanism of activation and the rewired network: New drug design concepts. Med Res Rev 2021; 42:770-799. [PMID: 34693559 PMCID: PMC8837674 DOI: 10.1002/med.21863] [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: 04/29/2021] [Revised: 07/06/2021] [Accepted: 10/07/2021] [Indexed: 12/13/2022]
Abstract
Precision oncology benefits from effective early phase drug discovery decisions. Recently, drugging inactive protein conformations has shown impressive successes, raising the cardinal questions of which targets can profit and what are the principles of the active/inactive protein pharmacology. Cancer driver mutations have been established to mimic the protein activation mechanism. We suggest that the decision whether to target an inactive (or active) conformation should largely rest on the protein mechanism of activation. We next discuss the recent identification of double (multiple) same-allele driver mutations and their impact on cell proliferation and suggest that like single driver mutations, double drivers also mimic the mechanism of activation. We further suggest that the structural perturbations of double (multiple) in cis mutations may reveal new surfaces/pockets for drug design. Finally, we underscore the preeminent role of the cellular network which is deregulated in cancer. Our structure-based review and outlook updates the traditional Mechanism of Action, informs decisions, and calls attention to the intrinsic activation mechanism of the target protein and the rewired tumor-specific network, ushering innovative considerations in precision medicine.
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Affiliation(s)
- Ruth Nussinov
- Computational Structural Biology Section, Frederick National Laboratory for Cancer Research in the Laboratory of Cancer Immunometabolism, National Cancer Institute, Frederick, Maryland, USA.,Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Mingzhen Zhang
- Computational Structural Biology Section, Frederick National Laboratory for Cancer Research in the Laboratory of Cancer Immunometabolism, National Cancer Institute, Frederick, Maryland, USA
| | - Ryan Maloney
- Computational Structural Biology Section, Frederick National Laboratory for Cancer Research in the Laboratory of Cancer Immunometabolism, National Cancer Institute, Frederick, Maryland, USA
| | - Chung-Jung Tsai
- Computational Structural Biology Section, Frederick National Laboratory for Cancer Research in the Laboratory of Cancer Immunometabolism, National Cancer Institute, Frederick, Maryland, USA
| | - Bengi Ruken Yavuz
- Department of Health Informatics, Graduate School of Informatics, Middle East Technical University, Ankara, Turkey
| | - Nurcan Tuncbag
- Department of Health Informatics, Graduate School of Informatics, Middle East Technical University, Ankara, Turkey.,Department of Chemical and Biological Engineering, College of Engineering, Koc University, Istanbul, Turkey.,Koc University Research Center for Translational Medicine, School of Medicine, Koc University, Istanbul, Turkey
| | - Hyunbum Jang
- Computational Structural Biology Section, Frederick National Laboratory for Cancer Research in the Laboratory of Cancer Immunometabolism, National Cancer Institute, Frederick, Maryland, USA
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6
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Raf promotes dimerization of the Ras G-domain with increased allosteric connections. Proc Natl Acad Sci U S A 2021; 118:2015648118. [PMID: 33653954 DOI: 10.1073/pnas.2015648118] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [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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7
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Nussinov R, Zhang M, Maloney R, Jang H. Ras isoform-specific expression, chromatin accessibility, and signaling. Biophys Rev 2021; 13:489-505. [PMID: 34466166 PMCID: PMC8355297 DOI: 10.1007/s12551-021-00817-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Accepted: 06/29/2021] [Indexed: 12/12/2022] Open
Abstract
The anchorage of Ras isoforms in the membrane and their nanocluster formations have been studied extensively, including their detailed interactions, sizes, preferred membrane environments, chemistry, and geometry. However, the staggering challenge of their epigenetics and chromatin accessibility in distinct cell states and types, which we propose is a major factor determining their specific expression, still awaits unraveling. Ras isoforms are distinguished by their C-terminal hypervariable region (HVR) which acts in intracellular transport, regulation, and membrane anchorage. Here, we review some isoform-specific activities at the plasma membrane from a structural dynamic standpoint. Inspired by physics and chemistry, we recognize that understanding functional specificity requires insight into how biomolecules can organize themselves in different cellular environments. Within this framework, we suggest that isoform-specific expression may largely be controlled by the chromatin density and physical compaction, which allow (or curb) access to "chromatinized DNA." Genes are preferentially expressed in tissues: proteins expressed in pancreatic cells may not be equally expressed in lung cells. It is the rule-not an exception, and it can be at least partly understood in terms of chromatin organization and accessibility state. Genes are expressed when they can be sufficiently exposed to the transcription machinery, and they are less so when they are persistently buried in dense chromatin. Notably, chromatin accessibility can similarly determine expression of drug resistance genes.
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Affiliation(s)
- Ruth Nussinov
- Computational Structural Biology Section Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research in the Laboratory of Cancer Immunometabolism National Cancer Institute, 1050 Boyles St, Frederick, MD 21702 USA
- Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine Tel Aviv University, 69978 Tel Aviv, Israel
| | - Mingzhen Zhang
- Computational Structural Biology Section Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research in the Laboratory of Cancer Immunometabolism National Cancer Institute, 1050 Boyles St, Frederick, MD 21702 USA
| | - Ryan Maloney
- Computational Structural Biology Section Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research in the Laboratory of Cancer Immunometabolism National Cancer Institute, 1050 Boyles St, Frederick, MD 21702 USA
| | - Hyunbum Jang
- Computational Structural Biology Section Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research in the Laboratory of Cancer Immunometabolism National Cancer Institute, 1050 Boyles St, Frederick, MD 21702 USA
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8
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Senyuz S, Jang H, Nussinov R, Keskin O, Gursoy A. Mechanistic Differences of Activation of Rac1 P29S and Rac1 A159V. J Phys Chem B 2021; 125:3790-3802. [PMID: 33848152 PMCID: PMC8154616 DOI: 10.1021/acs.jpcb.1c00883] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 03/31/2021] [Indexed: 12/26/2022]
Abstract
Rac1 is a small GTPase that plays key roles in actin reorganization, cell motility, and cell survival/growth as well as in various cancer types and neurodegenerative diseases. Similar to other Ras superfamily GTPases, Rac1 switches between active GTP-bound and inactive GDP-bound states. Switch I and II regions open and close during GDP/GTP exchange. P29S and A159V (paralogous to K-RasA146) mutations are the two most common somatic mutations of Rac1. Rac1P29S is a known hotspot for melanoma, whereas Rac1A159V most commonly occurs in head and neck cancer. To investigate how these substitutions induce the Rac1 dynamics, we used atomistic molecular dynamics simulations on the wild-type Rac1 and two mutant systems (P29S and A159V) in the GTP bound state, and on the wild-type Rac1 and P29S mutated system in the GDP bound state. Here, we show that P29S and A159V mutations activate Rac1 with different mechanisms. In Rac1P29S-GTP, the substitution increases the flexibility of Switch I based on RMSF and dihedral angle calculations and leads to an open conformation. We propose that the open Switch I conformation is one of the underlying reasons for rapid GDP/GTP exchange of Rac1P29S. On the other hand, in Rac1A159V-GTP, some of the contacts of the guanosine ring of GTP with Rac1 are temporarily lost, enabling the guanosine ring to move toward Switch I and subsequently close the switch. Rac1A159V-GTP adopts a Ras state 2 like conformation, where both switch regions are in closed conformation and Thr35 forms a hydrogen bond with the nucleotide.
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Affiliation(s)
- Simge Senyuz
- Computational
Science and Engineering, Koc University, Rumelifeneri Yolu, 34450 Sariyer, Istanbul, Turkey
| | - Hyunbum Jang
- Computational
Structural Biology Section, Frederick National Laboratory for Cancer
Research in the Laboratory of Cancer Immunometabolism, National Cancer Institute, Frederick, Maryland 21702, United States
| | - Ruth Nussinov
- Computational
Structural Biology Section, Frederick National Laboratory for Cancer
Research in the Laboratory of Cancer Immunometabolism, National Cancer Institute, Frederick, Maryland 21702, United States
- Department
of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Ozlem Keskin
- Chemical
and Biological Engineering, Koc University, Rumelifeneri Yolu, 34450 Sariyer, Istanbul, Turkey
| | - Attila Gursoy
- Computer
Engineering, Koc University, Rumelifeneri Yolu, 34450 Sariyer, Istanbul, Turkey
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9
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Jepson TA, Chung JK. Diffusion-based determination of protein homodimerization on reconstituted membrane surfaces. BMB Rep 2021. [PMID: 33408000 PMCID: PMC8016661 DOI: 10.5483/bmbrep.2021.54.3.228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
The transient interactions between cellular components, particularly on membrane surfaces, are critical in the proper function of many biochemical reactions. For example, many signaling pathways involve dimerization, oligomerization, or other types of clustering of signaling proteins as a key step in the signaling cascade. However, it is often experimentally challenging to directly observe and characterize the molecular mechanisms such interactions—the greatest difficulty lies in the fact that living cells have an unknown number of background processes that may or may not participate in the molecular process of interest, and as a consequence, it is usually impossible to definitively correlate an observation to a well-defined cellular mechanism. One of the experimental methods that can quantitatively capture these interactions is through membrane reconstitution, whereby a lipid bilayer is fabricated to mimic the membrane environment, and the biological components of interest are systematically introduced, without unknown background processes. This configuration allows the extensive use of fluorescence techniques, particularly fluorescence fluctuation spectroscopy and single-molecule fluorescence microscopy. In this review, we describe how the equilibrium diffusion of two proteins, K-Ras4B and the PH domain of Bruton’s tyrosine kinase (Btk), on fluid lipid membranes can be used to determine the kinetics of homodimerization reactions.
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Affiliation(s)
- Tyler A. Jepson
- Department of Chemistry, Colorado State University, Fort Collins, CO 80523, USA
| | - Jean K. Chung
- Department of Chemistry, Colorado State University, Fort Collins, CO 80523, USA
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10
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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: 16] [Impact Index Per Article: 5.3] [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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11
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Nussinov R, Jang H, Gursoy A, Keskin O, Gaponenko V. Inhibition of Nonfunctional Ras. Cell Chem Biol 2021; 28:121-133. [PMID: 33440168 PMCID: PMC7897307 DOI: 10.1016/j.chembiol.2020.12.012] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 10/28/2020] [Accepted: 12/21/2020] [Indexed: 02/07/2023]
Abstract
Intuitively, functional states should be targeted; not nonfunctional ones. So why could drugging the inactive K-Ras4BG12Cwork-but drugging the inactive kinase will likely not? The reason is the distinct oncogenic mechanisms. Kinase driver mutations work by stabilizing the active state and/or destabilizing the inactive state. Either way, oncogenic kinases are mostly in the active state. Ras driver mutations work by quelling its deactivation mechanisms, GTP hydrolysis, and nucleotide exchange. Covalent inhibitors that bind to the inactive GDP-bound K-Ras4BG12C conformation can thus work. By contrast, in kinases, allosteric inhibitors work by altering the active-site conformation to favor orthosteric drugs. From the translational standpoint this distinction is vital: it expedites effective pharmaceutical development and extends the drug classification based on the mechanism of action. Collectively, here we postulate that drug action relates to blocking the mechanism of activation, not to whether the protein is in the active or inactive state.
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Affiliation(s)
- Ruth Nussinov
- Computational Structural Biology Section, Frederick National Laboratory for Cancer Research in the Laboratory of Cancer Immunometabolism, National Cancer Institute, Frederick, MD 21702, USA; Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel.
| | - Hyunbum Jang
- Computational Structural Biology Section, Frederick National Laboratory for Cancer Research in the Laboratory of Cancer Immunometabolism, National Cancer Institute, Frederick, MD 21702, USA
| | - Attila Gursoy
- Department of Computer Engineering, Koc University, Istanbul 34450, Turkey
| | - Ozlem Keskin
- Department of Chemical and Biological Engineering, Koc University, Istanbul 34450, Turkey
| | - Vadim Gaponenko
- Department of Biochemistry and Molecular Genetics, University of Illinois at Chicago, Chicago, IL 60607, USA.
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12
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Chen X, Gao H, Long D. Millisecond Allosteric Dynamics of Activated Ras Reproduced with a Slowly Hydrolyzable GTP Analogue. Chembiochem 2020; 22:1079-1083. [PMID: 33140496 DOI: 10.1002/cbic.202000698] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 11/01/2020] [Indexed: 12/29/2022]
Abstract
The millisecond timescale dynamics of activated Ras transiently sample a low-populated conformational state that has distinct surface property from the major state and represents a promising target for binding of small-molecule compounds. To avoid the complications of hydrolysis, dynamics and other properties of active Ras have so far been routinely investigated by using non-hydrolyzable GTP analogues, which, however, were previously reported to alter both the kinetics and distribution of the conformational exchange. In this study, we quantitatively measured and validated the internal dynamics of Ras complexed with a slowly hydrolyzable GTP analogue, GTPγS, which increases the lifetime of active Ras by 23 times relative to that of native GTP. It was found that GTPγS, in addition to its better mimicking of the exchange kinetics than the commonly used non-hydrolyzable analogues GppNHp and GppCH2 p, can rigorously reproduce the natural dynamics network in active Ras, thus indicating its fitness for use in the development of allosteric inhibitors.
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Affiliation(s)
- Xiaomin Chen
- Hefei National Laboratory for Physical Sciences at the Microscale, MOE Key Laboratory for Membraneless Organelles & Cellular Dynamics, and School of Life Sciences, University of Science and Technology of China, 443 Huangshan Street, Hefei, Anhui, 230027, P. R. China
| | - Hexuan Gao
- Hefei National Laboratory for Physical Sciences at the Microscale, MOE Key Laboratory for Membraneless Organelles & Cellular Dynamics, and School of Life Sciences, University of Science and Technology of China, 443 Huangshan Street, Hefei, Anhui, 230027, P. R. China
| | - Dong Long
- Hefei National Laboratory for Physical Sciences at the Microscale, MOE Key Laboratory for Membraneless Organelles & Cellular Dynamics, and School of Life Sciences, University of Science and Technology of China, 443 Huangshan Street, Hefei, Anhui, 230027, P. R. China.,Department of Chemistry, University of Science and Technology of China Hefei, Anhui 230026, P. R. China
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KRAS(G12C)-AMG 510 interaction dynamics revealed by all-atom molecular dynamics simulations. Sci Rep 2020; 10:11992. [PMID: 32686745 PMCID: PMC7371895 DOI: 10.1038/s41598-020-68950-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Accepted: 07/03/2020] [Indexed: 01/02/2023] Open
Abstract
The first KRAS(G12C) targeting inhibitor in clinical development, AMG 510, has shown promising antitumor activity in clinical trials. On the molecular level, however, the interaction dynamics of this covalently bound drug–protein complex has been undetermined. Here, we disclose the interaction dynamics of the KRAS(G12C)–AMG 510 complex by long timescale all-atom molecular dynamics (MD) simulations (total of 75 μs). Moreover, we investigated the influence of the recently reported post-translational modification (PTM) of KRAS’ N-terminus, removal of initiator methionine (iMet1) with acetylation of Thr2, to this complex. Our results demonstrate that AMG 510 does not entrap KRAS into a single conformation, as one would expect based on the crystal structure, but rather into an ensemble of conformations. AMG 510 binding is extremely stable regardless of highly dynamic interface of KRAS’ switches. Overall, KRAS(G12C)–AMG 510 complex partially mimic the native dynamics of GDP bound KRAS; however, AMG 510 stabilizes the α3-helix region. N-terminally modified KRAS displays similar interaction dynamics with AMG 510 as when Met1 is present, but this PTM appears to stabilize β2–β3-loop. These results provide novel conformational insights on the molecular level to KRAS(G12C)–AMG 510 interactions and dynamics, providing new perspectives to RAS related drug discovery.
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