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Johnson CW, Fetics SK, Davis KP, Rodrigues JA, Mattos C. Allosteric site variants affect GTP hydrolysis on Ras. Protein Sci 2023; 32:e4767. [PMID: 37615343 PMCID: PMC10510474 DOI: 10.1002/pro.4767] [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: 04/21/2023] [Revised: 08/03/2023] [Accepted: 08/21/2023] [Indexed: 08/25/2023]
Abstract
RAS GTPases are proto-oncoproteins that regulate cell growth, proliferation, and differentiation in response to extracellular signals. The signaling functions of RAS, and other small GTPases, are dependent on their ability to cycle between GDP-bound and GTP-bound states. Structural analyses suggest that GTP hydrolysis catalyzed by HRAS can be regulated by an allosteric site located between helices 3, 4, and loop 7. Here we explore the relationship between intrinsic GTP hydrolysis on HRAS and the position of helix 3 and loop 7 through manipulation of the allosteric site, showing that the two sites are functionally connected. We generated several hydrophobic mutations in the allosteric site of HRAS to promote shifts in helix 3 relative to helix 4. By combining crystallography and enzymology to study these mutants, we show that closure of the allosteric site correlates with increased hydrolysis of GTP on HRAS in solution. Interestingly, binding to the RAS binding domain of RAF kinase (RAF-RBD) inhibits GTP hydrolysis in the mutants. This behavior may be representative of a cluster of mutations found in human tumors, which potentially cooperate with RAF complex formation to stabilize the GTP-bound state of RAS.
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Affiliation(s)
- Christian W. Johnson
- Department of Chemistry and Chemical BiologyNortheastern UniversityBostonMassachusettsUSA
| | - Susan K. Fetics
- Department of Molecular and Structural BiochemistryNorth Carolina State UniversityRaleighNorth CarolinaUSA
| | - Kathleen P. Davis
- Department of Molecular and Structural BiochemistryNorth Carolina State UniversityRaleighNorth CarolinaUSA
| | - Jose A. Rodrigues
- Department of Chemistry and Chemical BiologyNortheastern UniversityBostonMassachusettsUSA
| | - Carla Mattos
- Department of Chemistry and Chemical BiologyNortheastern UniversityBostonMassachusettsUSA
- Department of Molecular and Structural BiochemistryNorth Carolina State UniversityRaleighNorth CarolinaUSA
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2
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Kopra K, Valtonen S, Mahran R, Kapp JN, Hassan N, Gillette W, Dennis B, Li L, Westover KD, Plückthun A, Härmä H. Thermal Shift Assay for Small GTPase Stability Screening: Evaluation and Suitability. Int J Mol Sci 2022; 23:7095. [PMID: 35806100 PMCID: PMC9266822 DOI: 10.3390/ijms23137095] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 06/21/2022] [Accepted: 06/22/2022] [Indexed: 02/01/2023] Open
Abstract
Thermal unfolding methods are commonly used as a predictive technique by tracking the protein's physical properties. Inherent protein thermal stability and unfolding profiles of biotherapeutics can help to screen or study potential drugs and to find stabilizing or destabilizing conditions. Differential scanning calorimetry (DSC) is a 'Gold Standard' for thermal stability assays (TSA), but there are also a multitude of other methodologies, such as differential scanning fluorimetry (DSF). The use of an external probe increases the assay throughput, making it more suitable for screening studies, but the current methodologies suffer from relatively low sensitivity. While DSF is an effective tool for screening, interpretation and comparison of the results is often complicated. To overcome these challenges, we compared three thermal stability probes in small GTPase stability studies: SYPRO Orange, 8-anilino-1-naphthalenesulfonic acid (ANS), and the Protein-Probe. We studied mainly KRAS, as a proof of principle to obtain biochemical knowledge through TSA profiles. We showed that the Protein-Probe can work at lower concentration than the other dyes, and its sensitivity enables effective studies with non-covalent and covalent drugs at the nanomolar level. Using examples, we describe the parameters, which must be taken into account when characterizing the effect of drug candidates, of both small molecules and Designed Ankyrin Repeat Proteins.
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Affiliation(s)
- Kari Kopra
- Department of Chemistry, University of Turku, Henrikinkatu 2, 20500 Turku, Finland; (S.V.); (R.M.); (N.H.); (H.H.)
| | - Salla Valtonen
- Department of Chemistry, University of Turku, Henrikinkatu 2, 20500 Turku, Finland; (S.V.); (R.M.); (N.H.); (H.H.)
| | - Randa Mahran
- Department of Chemistry, University of Turku, Henrikinkatu 2, 20500 Turku, Finland; (S.V.); (R.M.); (N.H.); (H.H.)
| | - Jonas N. Kapp
- Department of Biochemistry, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland; (J.N.K.); (A.P.)
| | - Nazia Hassan
- Department of Chemistry, University of Turku, Henrikinkatu 2, 20500 Turku, Finland; (S.V.); (R.M.); (N.H.); (H.H.)
| | - William Gillette
- Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, 8560 Progress Dr., Frederick, MD 21702, USA;
| | - Bryce Dennis
- Departments of Biochemistry and Radiation Oncology, University of Texas Southwestern Medical Center at Dallas, 5323 Harry Hines Blvd, L4.270, Dallas, TX 75390, USA; (B.D.); (L.L.); (K.D.W.)
| | - Lianbo Li
- Departments of Biochemistry and Radiation Oncology, University of Texas Southwestern Medical Center at Dallas, 5323 Harry Hines Blvd, L4.270, Dallas, TX 75390, USA; (B.D.); (L.L.); (K.D.W.)
| | - Kenneth D. Westover
- Departments of Biochemistry and Radiation Oncology, University of Texas Southwestern Medical Center at Dallas, 5323 Harry Hines Blvd, L4.270, Dallas, TX 75390, USA; (B.D.); (L.L.); (K.D.W.)
| | - Andreas Plückthun
- Department of Biochemistry, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland; (J.N.K.); (A.P.)
| | - Harri Härmä
- Department of Chemistry, University of Turku, Henrikinkatu 2, 20500 Turku, Finland; (S.V.); (R.M.); (N.H.); (H.H.)
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3
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Shishina AK, Kovrigina EA, Galiakhmetov AR, Rathore R, Kovrigin EL. Study of Förster Resonance Energy Transfer to Lipid Domain Markers Ascertains Partitioning of Semisynthetic Lipidated N-Ras in Lipid Raft Nanodomains. Biochemistry 2018; 57:872-881. [PMID: 29280621 DOI: 10.1021/acs.biochem.7b01181] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Cellular membranes are heterogeneous planar lipid bilayers displaying lateral phase separation with the nanometer-scale liquid-ordered phase (also known as "lipid rafts") surrounded by the liquid-disordered phase. Many membrane-associated proteins were found to permanently integrate into the lipid rafts, which is critical for their biological function. Isoforms H and N of Ras GTPase possess a unique ability to switch their lipid domain preference depending on the type of bound guanine nucleotide (GDP or GTP). This behavior, however, has never been demonstrated in vitro in model bilayers with recombinant proteins and therefore has been attributed to the action of binding of Ras to other proteins at the membrane surface. In this paper, we report the observation of the nucleotide-dependent switch of lipid domain preferences of the semisynthetic lipidated N-Ras in lipid raft vesicles in the absence of additional proteins. To detect segregation of Ras molecules in raft and disordered lipid domains, we measured Förster resonance energy transfer between the donor fluorophore, mant, attached to the protein-bound guanine nucleotides, and the acceptor, rhodamine-conjugated lipid, localized into the liquid-disordered domains. Herein, we established that N-Ras preferentially populated raft domains when bound to mant-GDP, while losing its preference for rafts when it was associated with a GTP mimic, mant-GppNHp. At the same time, the isolated lipidated C-terminal peptide of N-Ras was found to be localized outside of the liquid-ordered rafts, most likely in the bulk-disordered lipid. Substitution of the N-terminal G domain of N-Ras with a homologous G domain of H-Ras disrupted the nucleotide-dependent lipid domain switch.
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Affiliation(s)
- Anna K Shishina
- Chemistry Department, Marquette University , P.O. Box 1881, Milwaukee, Wisconsin 53201, United States
| | - Elizaveta A Kovrigina
- Chemistry Department, Marquette University , P.O. Box 1881, Milwaukee, Wisconsin 53201, United States
| | - Azamat R Galiakhmetov
- Chemistry Department, Marquette University , P.O. Box 1881, Milwaukee, Wisconsin 53201, United States
| | - Rajendra Rathore
- Chemistry Department, Marquette University , P.O. Box 1881, Milwaukee, Wisconsin 53201, United States
| | - Evgenii L Kovrigin
- Chemistry Department, Marquette University , P.O. Box 1881, Milwaukee, Wisconsin 53201, United States
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4
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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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5
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Bandaru P, Shah NH, Bhattacharyya M, Barton JP, Kondo Y, Cofsky JC, Gee CL, Chakraborty AK, Kortemme T, Ranganathan R, Kuriyan J. Deconstruction of the Ras switching cycle through saturation mutagenesis. eLife 2017; 6:e27810. [PMID: 28686159 PMCID: PMC5538825 DOI: 10.7554/elife.27810] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Accepted: 07/05/2017] [Indexed: 02/02/2023] Open
Abstract
Ras proteins are highly conserved signaling molecules that exhibit regulated, nucleotide-dependent switching between active and inactive states. The high conservation of Ras requires mechanistic explanation, especially given the general mutational tolerance of proteins. Here, we use deep mutational scanning, biochemical analysis and molecular simulations to understand constraints on Ras sequence. Ras exhibits global sensitivity to mutation when regulated by a GTPase activating protein and a nucleotide exchange factor. Removing the regulators shifts the distribution of mutational effects to be largely neutral, and reveals hotspots of activating mutations in residues that restrain Ras dynamics and promote the inactive state. Evolutionary analysis, combined with structural and mutational data, argue that Ras has co-evolved with its regulators in the vertebrate lineage. Overall, our results show that sequence conservation in Ras depends strongly on the biochemical network in which it operates, providing a framework for understanding the origin of global selection pressures on proteins.
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Affiliation(s)
- Pradeep Bandaru
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States,California Institute for Quantitative Biosciences, University of California, Berkeley, Berkeley, United States,Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, United States
| | - Neel H Shah
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States,California Institute for Quantitative Biosciences, University of California, Berkeley, Berkeley, United States,Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, United States
| | - Moitrayee Bhattacharyya
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States,California Institute for Quantitative Biosciences, University of California, Berkeley, Berkeley, United States,Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, United States
| | - John P Barton
- Ragon Institute of MGH, MIT and Harvard, Cambridge, United States,Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, United States,Department of Physics, Massachusetts Institute of Technology, Cambridge, United States,Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, United States
| | - Yasushi Kondo
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States,California Institute for Quantitative Biosciences, University of California, Berkeley, Berkeley, United States,Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, United States
| | - Joshua C Cofsky
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States,California Institute for Quantitative Biosciences, University of California, Berkeley, Berkeley, United States,Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, United States
| | - Christine L Gee
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States,California Institute for Quantitative Biosciences, University of California, Berkeley, Berkeley, United States,Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, United States
| | - Arup K Chakraborty
- Ragon Institute of MGH, MIT and Harvard, Cambridge, United States,Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, United States,Department of Physics, Massachusetts Institute of Technology, Cambridge, United States,Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, United States,Department of Chemistry, Massachusetts Institute of Technology, Cambridge, United States,Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, United States
| | - Tanja Kortemme
- Department of Bioengineering and Therapeutic Sciences, California Institute for Quantitative Biomedical Research, University of California, San Francisco, San Francisco, United States
| | - Rama Ranganathan
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, United States,Green Center for Systems Biology, University of Texas Southwestern Medical Center, Dallas, United States,Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, United States, (RR)
| | - John Kuriyan
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States,California Institute for Quantitative Biosciences, University of California, Berkeley, Berkeley, United States,Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, United States,Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, United States, (JK)
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6
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Kovrigina EA, Galiakhmetov AR, Kovrigin EL. The Ras G Domain Lacks the Intrinsic Propensity to Form Dimers. Biophys J 2016; 109:1000-8. [PMID: 26331257 DOI: 10.1016/j.bpj.2015.07.020] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2015] [Revised: 05/27/2015] [Accepted: 07/07/2015] [Indexed: 12/24/2022] Open
Abstract
Ras GTPase is a molecular switch controlling a number of cellular pathways including growth, proliferation, differentiation, and apoptosis. Recent reports indicated that Ras undergoes dimerization at the membrane surface through protein-protein interactions. If firmly established this property of Ras would require profound reassessment of a large amount of published data and modification of the Ras signaling paradigm. One proposed mechanism of dimerization involves formation of salt bridges between the two GTPase domains (G domains) leading to formation of a compact dimer as observed in Ras crystal structures. In this work, we interrogated the intrinsic ability of Ras to self-associate in solution by creating conditions of high local concentration through irreversibly tethering the two G domains together at their unstructured C-terminal tails. We evaluated possible self-association in this inverted tandem conjugate via analysis of the time-domain fluorescence anisotropy and NMR chemical shift perturbations. We did not observe the increased rotational correlation time expected for the G domain dimer. Variation of the ionic strength (to modulate stability of the salt bridges) did not affect the rotational correlation time in the tandem further supporting independent rotational diffusion of two G domains. In a parallel line of experiments to detect and map weak self-association of the G domains, we analyzed NMR chemical shifts perturbations at a number of sites near the crystallographic dimer interface. The nearly complete lack of chemical shift perturbations in the tandem construct supported a simple model with the independent G domains repelled from each other by their overall negative charge. These results lead us to the conclusion that self-association of the G domains cannot be responsible for homodimerization of Ras reported in the literature.
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7
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Waudby CA, Ramos A, Cabrita LD, Christodoulou J. Two-Dimensional NMR Lineshape Analysis. Sci Rep 2016; 6:24826. [PMID: 27109776 PMCID: PMC4843008 DOI: 10.1038/srep24826] [Citation(s) in RCA: 130] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Accepted: 03/31/2016] [Indexed: 12/18/2022] Open
Abstract
NMR titration experiments are a rich source of structural, mechanistic, thermodynamic and kinetic information on biomolecular interactions, which can be extracted through the quantitative analysis of resonance lineshapes. However, applications of such analyses are frequently limited by peak overlap inherent to complex biomolecular systems. Moreover, systematic errors may arise due to the analysis of two-dimensional data using theoretical frameworks developed for one-dimensional experiments. Here we introduce a more accurate and convenient method for the analysis of such data, based on the direct quantum mechanical simulation and fitting of entire two-dimensional experiments, which we implement in a new software tool, TITAN (TITration ANalysis). We expect the approach, which we demonstrate for a variety of protein-protein and protein-ligand interactions, to be particularly useful in providing information on multi-step or multi-component interactions.
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Affiliation(s)
- Christopher A Waudby
- Institute of Structural and Molecular Biology, University College London and Birkbeck College, London WC1E 6BT, UK
| | - Andres Ramos
- Institute of Structural and Molecular Biology, University College London and Birkbeck College, London WC1E 6BT, UK
| | - Lisa D Cabrita
- Institute of Structural and Molecular Biology, University College London and Birkbeck College, London WC1E 6BT, UK
| | - John Christodoulou
- Institute of Structural and Molecular Biology, University College London and Birkbeck College, London WC1E 6BT, UK
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8
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Amin N, Chiarparin E, Coyle J, Nietlispach D, Williams G. 1H, 15N and 13C backbone assignments of GDP-bound human H-Ras mutant G12V. BIOMOLECULAR NMR ASSIGNMENTS 2016; 10:121-3. [PMID: 26373425 DOI: 10.1007/s12104-015-9649-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Accepted: 09/09/2015] [Indexed: 05/27/2023]
Abstract
Harvey Ras (H-Ras) is a membrane-associated GTPase with critical functions in cell proliferation and differentiation. The G12V mutant of H-Ras is one of the most commonly encountered oncoproteins in human cancer. This mutation disrupts the GTPase activity of H-Ras, leading to constitutive activation and aberrant downstream signalling. Here we report the backbone resonance assignments of human H-Ras mutant G12V lacking the C-terminal membrane attachment domain.
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Affiliation(s)
- Nader Amin
- Astex Pharmaceuticals, 436 Cambridge Science Park, Cambridge, CB4 0QA, UK
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK
| | - Elisabetta Chiarparin
- Astex Pharmaceuticals, 436 Cambridge Science Park, Cambridge, CB4 0QA, UK
- AstraZeneca, 310 Cambridge Science Park, Cambridge, CB4 0FZ, UK
| | - Joe Coyle
- Astex Pharmaceuticals, 436 Cambridge Science Park, Cambridge, CB4 0QA, UK
| | - Daniel Nietlispach
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Rd, Cambridge, CB2 1GA, UK
| | - Glyn Williams
- Astex Pharmaceuticals, 436 Cambridge Science Park, Cambridge, CB4 0QA, UK.
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9
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McCarthy M, Prakash P, Gorfe AA. Computational allosteric ligand binding site identification on Ras proteins. Acta Biochim Biophys Sin (Shanghai) 2016; 48:3-10. [PMID: 26487442 DOI: 10.1093/abbs/gmv100] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Accepted: 08/16/2015] [Indexed: 12/19/2022] Open
Abstract
A number of computational techniques have been proposed to expedite the process of allosteric ligand binding site identification in inherently flexible and hence challenging drug targets. Some of these techniques have been instrumental in the discovery of allosteric ligand binding sites on Ras proteins, a group of elusive anticancer drug targets. This review provides an overview of these techniques and their application to Ras proteins. A summary of molecular docking and binding site identification is provided first, followed by a more detailed discussion of two specific techniques for binding site identification in ensembles of Ras conformations generated by molecular simulations.
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Affiliation(s)
- Michael McCarthy
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Priyanka Prakash
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Alemayehu A Gorfe
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
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10
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Fetics SK, Guterres H, Kearney BM, Buhrman G, Ma B, Nussinov R, Mattos C. Allosteric effects of the oncogenic RasQ61L mutant on Raf-RBD. Structure 2015; 23:505-516. [PMID: 25684575 PMCID: PMC7755167 DOI: 10.1016/j.str.2014.12.017] [Citation(s) in RCA: 175] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Revised: 12/07/2014] [Accepted: 12/17/2014] [Indexed: 10/24/2022]
Abstract
The Ras/Raf/MEK/ERK signal transduction pathway is a major regulator of cell proliferation activated by Ras-guanosine triphosphate (GTP). The oncogenic mutant RasQ61L is not able to hydrolyze GTP in the presence of Raf and thus is a constitutive activator of this mitogenic pathway. The Ras/Raf interaction is essential for the activation of the Raf kinase domain through a currently unknown mechanism. We present the crystal structures of the Ras-GppNHp/Raf-RBD and RasQ61L-GppNHp/Raf-RBD complexes, which, in combination with MD simulations, reveal differences in allosteric interactions leading from the Ras/Raf interface to the Ras calcium-binding site and to the remote Raf-RBD loop L4. In the presence of Raf, the RasQ61L mutant has a rigid switch II relative to the wild-type and increased flexibility at the interface with switch I, which propagates across Raf-RBD. We show that in addition to local perturbations on Ras, RasQ61L has substantial long-range effects on the Ras allosteric lobe and on Raf-RBD.
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Affiliation(s)
- Susan K Fetics
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA 02115, USA; Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, NC 27695, USA
| | - Hugo Guterres
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA 02115, USA
| | - Bradley M Kearney
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA 02115, USA; Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, NC 27695, USA
| | - Greg Buhrman
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, NC 27695, USA
| | - Buyong Ma
- Basic Science Program, Leidos Biomedical Research, Inc., Cancer and Inflammation Program, National Cancer Institute, Frederick, MD 21702, USA
| | - Ruth Nussinov
- Basic Science Program, Leidos Biomedical Research, Inc., Cancer and Inflammation Program, National Cancer Institute, Frederick, MD 21702, USA; Department of Human Genetics, Sackler Institute of Molecular Medicine, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Carla Mattos
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA 02115, USA; Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, NC 27695, USA.
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11
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Johnson CW, Mattos C. The Allosteric Switch and Conformational States in Ras GTPase Affected by Small Molecules. INHIBITORS OF THE RAS SUPERFAMILY G-PROTEINS, PART A 2013; 33 Pt A:41-67. [DOI: 10.1016/b978-0-12-416749-0.00003-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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