1
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Hutchins CM, Gorfe AA. From disorder comes function: Regulation of small GTPase function by intrinsically disordered lipidated membrane anchor. Curr Opin Struct Biol 2024; 87:102869. [PMID: 38943706 PMCID: PMC11283958 DOI: 10.1016/j.sbi.2024.102869] [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: 04/15/2024] [Revised: 05/23/2024] [Accepted: 06/04/2024] [Indexed: 07/01/2024]
Abstract
The intrinsically disordered, lipid-modified membrane anchor of small GTPases is emerging as a critical modulator of function through its ability to sort lipids in a conformation-dependent manner. We reviewed recent computational and experimental studies that have begun to shed light on the sequence-ensemble-function relationship in this unique class of lipidated intrinsically disordered regions (LIDRs).
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Affiliation(s)
- Chase M Hutchins
- Department of Integrative Biology and Pharmacology, McGovern Medical School, University of Texas Health Science Center at Houston, 6431 Fannin St., Houston, TX 77030, USA; Biochemistry and Cell Biology Program & Therapeutics and Pharmacology Program, MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, 6431 Fannin St., Houston, TX 77030, USA. https://twitter.com/chasedsims
| | - 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; Biochemistry and Cell Biology Program & Therapeutics and Pharmacology Program, MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, 6431 Fannin St., Houston, TX 77030, USA.
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2
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Gu X, Zhang Y, Long D. Conserved allosteric perturbation of the GTPase domains by region 1 of Ras hypervariable regions. Biophys J 2024; 123:839-846. [PMID: 38419331 PMCID: PMC10995424 DOI: 10.1016/j.bpj.2024.02.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Revised: 02/19/2024] [Accepted: 02/26/2024] [Indexed: 03/02/2024] Open
Abstract
Ras proteins are important intracellular signaling hubs that can interact with numerous downstream effectors and upstream regulators through their GTPase domains (G-domains) anchored to plasma membranes by the C-terminal hypervariable regions (HVRs). The biological functions of Ras were proposed to be regulated at multiple levels including the intramolecular G-domain-HVR interactions, of which the exact mechanism and specificity are still controversial. Here, we demonstrate that the HVRs, instead of having direct contacts, can weakly perturb the G-domains via an allosteric interaction that is restricted to a ∼20 Å range and highly conserved in the tested Ras isoforms (HRas and KRas4B) and nucleotide-bound states. The origin of this allosteric perturbation has been localized to a short segment (residues 167-171) coinciding with region 1 of HVRs, which exhibits moderate to weak α-helical propensities. A charge-reversal mutation (E168K) of KRas4B in region 1, previously described in the Catalog of Somatic Mutations in Cancer database, was found to induce similar chemical shift perturbations as truncation of the HVR does. Further membrane paramagnetic relaxation enhancement (mPRE) data show that this region 1 mutation alters the membrane orientations of KRas4B and moderately increases the relative population of the signaling-compatible state.
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Affiliation(s)
- Xue Gu
- MOE Key Laboratory for Cellular Dynamics, School of Life Sciences, University of Science and Technology of China, Hefei, China
| | - Yalong Zhang
- MOE Key Laboratory for Cellular Dynamics, School of Life Sciences, University of Science and Technology of China, Hefei, China
| | - Dong Long
- MOE Key Laboratory for Cellular Dynamics, School of Life Sciences, University of Science and Technology of China, Hefei, China; Department of Chemistry, University of Science and Technology of China, Hefei, China.
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3
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Farcas A, Janosi L. GTP-Bound N-Ras Conformational States and Substates Are Modulated by Membrane and Point Mutation. Int J Mol Sci 2024; 25:1430. [PMID: 38338709 PMCID: PMC11154311 DOI: 10.3390/ijms25031430] [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: 11/29/2023] [Revised: 01/11/2024] [Accepted: 01/17/2024] [Indexed: 02/12/2024] Open
Abstract
Oncogenic Ras proteins are known to present multiple conformational states, as reported by the great variety of crystallographic structures. The GTP-bound states are grouped into two main states: the "inactive" state 1 and the "active" state 2. Recent reports on H-Ras have shown that state 2 exhibits two substates, directly related to the orientation of Tyr32: toward the GTP-bound pocket and outwards. In this paper, we show that N-Ras exhibits another substate of state 2, related to a third orientation of Tyr32, toward Ala18 and parallel to the GTP-bound pocket. We also show that this substate is highly sampled in the G12V mutation of N-Ras and barely present in its wild-type form, and that the G12V mutation prohibits the sampling of the GTPase-activating protein (GAP) binding substate, rendering this mutation oncogenic. Furthermore, using molecular dynamics simulations, we explore the importance of the membrane on N-Ras' conformational state dynamics and its strong influence on Ras protein stability. Moreover, the membrane has a significant influence on the conformational (sub)states sampling of Ras. This, in turn, is of crucial importance in the activation/deactivation cycle of Ras, due to the binding of guanine nucleotide exchange factor proteins (GEFs)/GTPase-activating proteins (GAPs).
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Affiliation(s)
| | - Lorant Janosi
- Department of Molecular and Biomolecular Physics, National Institute for Research and Development of Isotopic and Molecular Technologies, 67-103 Donat Street, 400293 Cluj-Napoca, Romania;
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4
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Liang X, Jung SY, Fong LW, Bildik G, Gray JP, Mao W, Zhang S, Millward SW, Gorfe AA, Zhou Y, Lu Z, Bast RC. Membrane anchoring of the DIRAS3 N-terminal extension permits tumor suppressor function. iScience 2023; 26:108151. [PMID: 37915607 PMCID: PMC10616557 DOI: 10.1016/j.isci.2023.108151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 08/16/2023] [Accepted: 10/03/2023] [Indexed: 11/03/2023] Open
Abstract
DIRAS3 is an imprinted tumor suppressor gene encoding a GTPase that has a distinctive N-terminal extension (NTE) not found in other RAS proteins. This NTE and the prenylated C-terminus are required for DIRAS3-mediated inhibition of RAS/MAP signaling and PI3K activity at the plasma membrane. In this study, we applied biochemical, biophysical, and computational methods to characterize the structure and function of the NTE. The NTE peptide recognizes phosphoinositides PI(3,4,5)P3 and PI(4,5)P2 with rapid kinetics and strong affinity. Lipid binding induces NTE structural change from disorder to amphipathic helix. Mass spectrometry identified N-myristoylation of DIRAS3. All-atom molecular dynamic simulations predict DIRAS3 could adhere to the membrane through both termini, suggesting the NTE is involved in targeting and stabilizing DIRAS3 on the membrane by double anchoring. Overall, our results are consistent with DIRAS3's function as a tumor suppressor, whereby the membrane-bound DIRAS3 can effectively target PI3K and KRAS at the membrane.
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Affiliation(s)
- Xiaowen Liang
- Department of Experimental Therapeutics, University of Texas MD Anderson Cancer Center, Houston, TX 77054, USA
| | - Sung Yun Jung
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Lon Wolf Fong
- Department of Experimental Therapeutics, University of Texas MD Anderson Cancer Center, Houston, TX 77054, USA
| | - Gamze Bildik
- Department of Experimental Therapeutics, University of Texas MD Anderson Cancer Center, Houston, TX 77054, USA
| | - Joshua P. Gray
- Department of Experimental Therapeutics, University of Texas MD Anderson Cancer Center, Houston, TX 77054, USA
| | - Weiqun Mao
- Department of Experimental Therapeutics, University of Texas MD Anderson Cancer Center, Houston, TX 77054, USA
| | - Shuxing Zhang
- Department of Experimental Therapeutics, University of Texas MD Anderson Cancer Center, Houston, TX 77054, USA
| | - Steven W. Millward
- Department of Cancer Systems Imaging, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Alemayehu A. Gorfe
- Department of Integrative Biology and Pharmacology, McGovern Medical School, University of Texas Health Science Center, Houston, TX 77030, USA
| | - Yong Zhou
- Department of Integrative Biology and Pharmacology, McGovern Medical School, University of Texas Health Science Center, Houston, TX 77030, USA
| | - Zhen Lu
- Department of Experimental Therapeutics, University of Texas MD Anderson Cancer Center, Houston, TX 77054, USA
| | - Robert C. Bast
- Department of Experimental Therapeutics, University of Texas MD Anderson Cancer Center, Houston, TX 77054, USA
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5
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Araya MK, Gorfe AA. Conformational ensemble-dependent lipid recognition and segregation by prenylated intrinsically disordered regions in small GTPases. Commun Biol 2023; 6:1111. [PMID: 37919400 PMCID: PMC10622456 DOI: 10.1038/s42003-023-05487-6] [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: 05/15/2023] [Accepted: 10/19/2023] [Indexed: 11/04/2023] Open
Abstract
We studied diverse prenylated intrinsically disordered regions (PIDRs) of Ras and Rho family small GTPases using long timescale atomistic molecular dynamics simulations in an asymmetric model membrane of phosphatidylcholine (PC) and phosphatidylserine (PS) lipids. Here we show that conformational plasticity is a key determinant of lipid sorting by polybasic PIDRs and provide evidence for lipid sorting based on both headgroup and acyl chain structures. We further show that conformational ensemble-based lipid recognition is generalizable to all polybasic PIDRs, and that the sequence outside the polybasic domain (PBD) modulates the conformational plasticity, bilayer adsorption, and interactions of PIDRs with membrane lipids. Specifically, we find that palmitoylation, the ratio of basic to acidic residues, and the hydrophobic content of the sequence outside the PBD significantly impact the diversity of conformational substates and hence the extent of conformation-dependent lipid interactions. We thus propose that the PBD is required but not sufficient for the full realization of lipid sorting by prenylated PBD-containing membrane anchors, and that the membrane anchor is not only responsible for high affinity membrane binding but also directs the protein to the right target membrane where it participates in lipid sorting.
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Affiliation(s)
- Mussie K Araya
- McGovern Medical School, University of Texas Health Science Center at Houston, Department of Integrative Biology and Pharmacology, 6431 Fannin St., Houston, TX, 77030, USA
| | - Alemayehu A Gorfe
- McGovern Medical School, University of Texas Health Science Center at Houston, Department of Integrative Biology and Pharmacology, 6431 Fannin St., Houston, TX, 77030, USA.
- Biochemistry and Cell Biology Program & Therapeutics and Pharmacology Program, UTHealth MD Anderson Cancer Center Graduate School of Biomedical Sciences, Houston, 6431 Fannin St., TX, 77030, USA.
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6
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Liu J, Arora N, Zhou Y. RAS GTPases and Interleaflet Coupling in the Plasma Membrane. Cold Spring Harb Perspect Biol 2023; 15:a041414. [PMID: 37463719 PMCID: PMC10513163 DOI: 10.1101/cshperspect.a041414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/20/2023]
Abstract
RAS genes are frequently mutated in cancer. The primary signaling compartment of wild-type and constitutively active oncogenic mutant RAS proteins is the inner leaflet of the plasma membrane (PM). Thus, a better understanding of the unique environment of the PM inner leaflet is important to shed further light on RAS function. Over the past few decades, an integrated approach of superresolution imaging, molecular dynamic simulations, and biophysical assays has yielded new insights into the capacity of RAS proteins to sort lipids with specific headgroups and acyl chains, to assemble signaling nanoclusters on the inner PM. RAS proteins also sense and respond to changes in components of the outer PM leaflet, including glycophosphatidylinositol-anchored proteins, sphingophospholipids, glycosphingolipids, and galectins, as well as cholesterol that translocates between the two leaflets. Such communication between the inner and outer leaflets of the PM, called interleaflet coupling, allows RAS to potentially integrate extracellular mechanical and electrostatic information with intracellular biochemical signaling events, and reciprocally allows mutant RAS-transformed tumor cells to modify tumor microenvironments. Here, we review RAS-lipid interactions and speculate on potential mechanisms that allow communication between the opposing leaflets of the PM.
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Affiliation(s)
- Junchen Liu
- Department of Integrative Biology and Pharmacology, McGovern Medical School, University of Texas Health Science Center, Houston, Texas 77030, USA
| | - Neha Arora
- Department of Integrative Biology and Pharmacology, McGovern Medical School, University of Texas Health Science Center, Houston, Texas 77030, USA
| | - Yong Zhou
- Department of Integrative Biology and Pharmacology, McGovern Medical School, University of Texas Health Science Center, Houston, Texas 77030, USA
- Biochemistry and Cell Biology Program, Graduate School of Biomedical Sciences, MD Anderson Cancer Center and University of Texas, Houston, Texas 77030, USA
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7
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Pagba CV, Gupta AK, Gorfe AA. Small-Molecule Inhibition of KRAS through Conformational Selection. ACS OMEGA 2023; 8:31419-31426. [PMID: 37663463 PMCID: PMC10468774 DOI: 10.1021/acsomega.3c04013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Accepted: 08/09/2023] [Indexed: 09/05/2023]
Abstract
Mutations in KRAS account for about 20% of human cancers. Despite the major progress in recent years toward the development of KRAS inhibitors, including the discovery of covalent inhibitors of the G12C KRAS variant for the treatment of non-small-cell lung cancer, much work remains to be done to discover broad-acting inhibitors to treat many other KRAS-driven cancers. In a previous report, we showed that a 308.4 Da small-molecule ligand [(2R)-2-(N'-(1H-indole-3-carbonyl)hydrazino)-2-phenyl-acetamide] binds to KRAS with low micro-molar affinity [Chem. Biol. Drug Des.2019; 94(2):1441-1456]. Binding of this ligand, which we call ACA22, to the p1 pocket of KRAS and its interactions with residues at beta-strand 1 and the switch loops have been supported by data from nuclear magnetic resonance spectroscopy and microscale thermophoresis experiments. However, the inhibitory potential of the compound was not demonstrated. Here, we show that ACA22 inhibits KRAS-mediated signal transduction in cells expressing wild type (WT) and G12D mutant KRAS and reduces levels of guanosine triphosphate-loaded WT KRAS more effectively than G12D KRAS. We ruled out the direct effect on nucleotide exchange or effector binding as possible mechanisms of inhibition using a variety of biophysical assays. Combining these observations with binding data that show comparable affinities of the compound for the active and inactive forms of the mutant but not the WT, we propose conformational selection as a possible mechanism of action of ACA22.
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Affiliation(s)
- Cynthia V Pagba
- Department of Integrative Biology and Pharmacology, McGovern Medical School, University of Texas Health Science Center at Houston, 6431 Fannin Street, Houston, Texas 77030, United States
| | - Amit K Gupta
- Department of Integrative Biology and Pharmacology, McGovern Medical School, 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, McGovern Medical School, University of Texas Health Science Center at Houston, 6431 Fannin Street, Houston, Texas 77030, United States
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8
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Araya MK, Gorfe AA. Conformational ensemble dependent lipid recognition and segregation by prenylated intrinsically disordered regions in small GTPases. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.11.553039. [PMID: 37609330 PMCID: PMC10441427 DOI: 10.1101/2023.08.11.553039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/24/2023]
Abstract
We studied diverse prenylated intrinsically disordered regions (PIDRs) of Ras and Rho family small GTPases using long timescale atomistic molecular dynamics simulations in an asymmetric model membrane of phosphatidylcholine (PC) and phosphatidylserine (PS) lipids. We show that conformational plasticity is a key determinant of lipid sorting by polybasic PIDRs and provide evidence for lipid sorting based on both headgroup and acyl chain structures. We further show that conformational ensemble-based lipid recognition is generalizable to all polybasic PIDRs, and that the sequence outside the polybasic domain (PBD) modulates the conformational plasticity, bilayer adsorption, and interactions of PIDRs with membrane lipids. Specifically, we found that palmitoylation, the ratio of basic to acidic residues, and the hydrophobic content of the sequence outside the PBD significantly impact the diversity of conformational substates and hence the extent of conformation-dependent lipid interactions. We thus propose that the PBD is required but not sufficient for the full realization of lipid sorting by prenylated PBD-containing membrane anchors, and that the membrane anchor is not only responsible for high affinity membrane binding but also directs the protein to the right target membrane where it participates in lipid sorting.
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9
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Ikari M, Yagi H, Kasai T, Inomata K, Ito M, Higuchi K, Matsuda N, Ito Y, Kigawa T. Direct Observation of Membrane-Associated H-Ras in the Native Cellular Environment by In-Cell 19F-NMR Spectroscopy. JACS AU 2023; 3:1658-1669. [PMID: 37388687 PMCID: PMC10302746 DOI: 10.1021/jacsau.3c00108] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 05/15/2023] [Accepted: 05/15/2023] [Indexed: 07/01/2023]
Abstract
Ras acts as a molecular switch to control intracellular signaling on the plasma membrane (PM). Elucidating how Ras associates with PM in the native cellular environment is crucial for understanding its control mechanism. Here, we used in-cell nuclear magnetic resonance (NMR) spectroscopy combined with site-specific 19F-labeling to explore the membrane-associated states of H-Ras in living cells. The site-specific incorporation of p-trifluoromethoxyphenylalanine (OCF3Phe) at three different sites of H-Ras, i.e., Tyr32 in switch I, Tyr96 interacting with switch II, and Tyr157 on helix α5, allowed the characterization of their conformational states depending on the nucleotide-bound states and an oncogenic mutational state. Exogenously delivered 19F-labeled H-Ras protein containing a C-terminal hypervariable region was assimilated via endogenous membrane-trafficking, enabling proper association with the cell membrane compartments. Despite poor sensitivity of the in-cell NMR spectra of membrane-associated H-Ras, the Bayesian spectral deconvolution identified distinct signal components on three 19F-labeled sites, thus offering the conformational multiplicity of H-Ras on the PM. Our study may be helpful in elucidating the atomic-scale picture of membrane-associated proteins in living cells.
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Affiliation(s)
- Masaomi Ikari
- RIKEN
Center for Biosystems Dynamics Research, Kanagawa 230-0045, Japan
| | - Hiromasa Yagi
- RIKEN
Center for Biosystems Dynamics Research, Kanagawa 230-0045, Japan
| | - Takuma Kasai
- RIKEN
Center for Biosystems Dynamics Research, Kanagawa 230-0045, Japan
- PRESTO/Japan
Science and Technology Agency, Saitama 332-0012, Japan
| | - Kohsuke Inomata
- RIKEN
Center for Biosystems Dynamics Research, Kanagawa 230-0045, Japan
- PRESTO/Japan
Science and Technology Agency, Saitama 332-0012, Japan
| | - Masahiro Ito
- RIKEN
Center for Biosystems Dynamics Research, Kanagawa 230-0045, Japan
| | - Kae Higuchi
- RIKEN
Center for Biosystems Dynamics Research, Kanagawa 230-0045, Japan
| | - Natsuko Matsuda
- RIKEN
Center for Biosystems Dynamics Research, Kanagawa 230-0045, Japan
- SI Innovation
Center, Taiyo Nippon Sanso Corporation, Tokyo 206-0001, Japan
| | - Yutaka Ito
- Department
of Chemistry, Graduate School of Science, Tokyo Metropolitan University, Tokyo 192-0397, Japan
| | - Takanori Kigawa
- RIKEN
Center for Biosystems Dynamics Research, Kanagawa 230-0045, Japan
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10
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Gu X, Liu D, Yu Y, Wang H, Long D. Quantitative Paramagnetic NMR-Based Analysis of Protein Orientational Dynamics on Membranes: Dissecting the KRas4B-Membrane Interactions. J Am Chem Soc 2023; 145:10295-10303. [PMID: 37116086 DOI: 10.1021/jacs.3c01597] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/30/2023]
Abstract
Peripheral membrane proteins can adopt distinct orientations on the surfaces of lipid bilayers that are often short-lived and challenging to characterize by conventional experimental methods. Here we describe a robust approach for mapping protein orientational landscapes through quantitative interpretation of paramagnetic relaxation enhancement (PRE) data arising from membrane mimetics with spin-labeled lipids. Theoretical analysis, followed by experimental verification, reveals insights into the distinct properties of the PRE observables that are generally distorted in the case of stably membrane-anchored proteins. To suppress the artifacts, we demonstrate that undistorted Γ2 values can be obtained via transient membrane anchoring, based on which a computational framework is established for deriving accurate orientational ensembles obeying Boltzmann statistics. Application of the approach to KRas4B, a classical peripheral membrane protein whose orientations are critical for its functions and drug design, reveals four distinct orientational states that are close but not identical to those reported previously. Similar orientations are also found for a truncated KRas4B without the hypervariable region (HVR) that can sample a broader range of orientations, suggesting a confinement role of the HVR geometrically prohibiting severe tilting. Comparison of the KRas4B Γ2 rates measured using nanodiscs containing different types of anionic lipids reveals identical Γ2 patterns for the G-domain but different ones for the HVR, indicating only the latter is able to selectively interact with anionic lipids.
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Affiliation(s)
- Xue Gu
- MOE Key Laboratory for Cellular Dynamics, School of Life Sciences, University of Science and Technology of China, Hefei 230027, China
| | - Dan Liu
- MOE Key Laboratory for Cellular Dynamics, School of Life Sciences, University of Science and Technology of China, Hefei 230027, China
| | - Yongkui Yu
- MOE Key Laboratory for Cellular Dynamics, School of Life Sciences, University of Science and Technology of China, Hefei 230027, China
| | - Hui Wang
- MOE Key Laboratory for Cellular Dynamics, School of Life Sciences, University of Science and Technology of China, Hefei 230027, China
| | - Dong Long
- MOE Key Laboratory for Cellular Dynamics, School of Life Sciences, University of Science and Technology of China, Hefei 230027, China
- Department of Chemistry, University of Science and Technology of China, Hefei 230026, China
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11
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Babu Manoharan G, Guzmán C, Najumudeen AK, Abankwa D. Detection of Ras nanoclustering-dependent homo-FRET using fluorescence anisotropy measurements. Eur J Cell Biol 2023; 102:151314. [PMID: 37058825 DOI: 10.1016/j.ejcb.2023.151314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 03/10/2023] [Accepted: 04/10/2023] [Indexed: 04/16/2023] Open
Abstract
The small GTPase Ras is frequently mutated in cancer and a driver of tumorigenesis. The recent years have shown great progress in drug-targeting Ras and understanding how it operates on the plasma membrane. We now know that Ras is non-randomly organized into proteo-lipid complexes on the membrane, called nanoclusters. Nanoclusters contain only a few Ras proteins and are necessary for the recruitment of downstream effectors, such as Raf. If tagged with fluorescent proteins, the dense packing of Ras in nanoclusters can be analyzed by Förster/ fluorescence resonance energy transfer (FRET). Loss of FRET can therefore report on decreased nanoclustering and any process upstream of it, such as Ras lipid modifications and correct trafficking. Thus, cellular FRET screens employing Ras-derived fluorescence biosensors are potentially powerful tools to discover chemical or genetic modulators of functional Ras membrane organization. Here we implement fluorescence anisotropy-based homo-FRET measurements of Ras-derived constructs labelled with only one fluorescent protein on a confocal microscope and a fluorescence plate reader. We show that homo-FRET of both H-Ras- and K-Ras-derived constructs can sensitively report on Ras-lipidation and -trafficking inhibitors, as well as on genetic perturbations of proteins regulating membrane anchorage. By exploiting the switch I/II-binding Ras-dimerizing compound BI-2852, this assay is also suitable to report on the engagement of the K-Ras switch II pocket by small molecules such as AMG 510. Given that homo-FRET only requires one fluorescent protein tagged Ras construct, this approach has significant advantages to create Ras-nanoclustering FRET-biosensor reporter cell lines, as compared to the more common hetero-FRET approaches.
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Affiliation(s)
- Ganesh Babu Manoharan
- Cancer Cell Biology and Drug Discovery group, Department of Life Sciences and Medicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Camilo Guzmán
- Euro-BioImaging ERIC, Statutory Seat, Turku, Finland
| | - Arafath Kaja Najumudeen
- Institute of Biotechnology, HiLIFE Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
| | - Daniel Abankwa
- Cancer Cell Biology and Drug Discovery group, Department of Life Sciences and Medicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg.
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12
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Mathy CJP, Mishra P, Flynn JM, Perica T, Mavor D, Bolon DNA, Kortemme T. A complete allosteric map of a GTPase switch in its native cellular network. Cell Syst 2023; 14:237-246.e7. [PMID: 36801015 PMCID: PMC10173951 DOI: 10.1016/j.cels.2023.01.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2022] [Revised: 11/08/2022] [Accepted: 01/06/2023] [Indexed: 02/19/2023]
Abstract
Allosteric regulation is central to protein function in cellular networks. A fundamental open question is whether cellular regulation of allosteric proteins occurs only at a few defined positions or at many sites distributed throughout the structure. Here, we probe the regulation of GTPases-protein switches that control signaling through regulated conformational cycling-at residue-level resolution by deep mutagenesis in the native biological network. For the GTPase Gsp1/Ran, we find that 28% of the 4,315 assayed mutations show pronounced gain-of-function responses. Twenty of the sixty positions enriched for gain-of-function mutations are outside the canonical GTPase active site switch regions. Kinetic analysis shows that these distal sites are allosterically coupled to the active site. We conclude that the GTPase switch mechanism is broadly sensitive to cellular allosteric regulation. Our systematic discovery of new regulatory sites provides a functional map to interrogate and target GTPases controlling many essential biological processes.
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Affiliation(s)
- Christopher J P Mathy
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA 94158, USA; Quantitative Biosciences Institute, University of California, San Francisco, San Francisco, CA 94158, USA; The UC Berkeley-UCSF Graduate Program in Bioengineering, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Parul Mishra
- Department of Biochemistry and Molecular Biotechnology, University of Massachusetts Medical School, Worcester, MA 01605, USA; School of Life Sciences, University of Hyderabad, Hyderabad, Telangana, India
| | - Julia M Flynn
- Department of Biochemistry and Molecular Biotechnology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Tina Perica
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA 94158, USA; Quantitative Biosciences Institute, University of California, San Francisco, San Francisco, CA 94158, USA
| | - David Mavor
- Department of Biochemistry and Molecular Biotechnology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Daniel N A Bolon
- Department of Biochemistry and Molecular Biotechnology, University of Massachusetts Medical School, Worcester, MA 01605, USA.
| | - Tanja Kortemme
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA 94158, USA; Quantitative Biosciences Institute, University of California, San Francisco, San Francisco, CA 94158, USA; The UC Berkeley-UCSF Graduate Program in Bioengineering, University of California, San Francisco, San Francisco, CA 94158, USA; Chan Zuckerberg Biohub, San Francisco, CA 94158, USA.
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13
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Zhou Y, Hancock JF. RAS nanoclusters are cell surface transducers that convert extracellular stimuli to intracellular signalling. FEBS Lett 2023; 597:892-908. [PMID: 36595205 PMCID: PMC10919257 DOI: 10.1002/1873-3468.14569] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 12/05/2022] [Accepted: 12/12/2022] [Indexed: 01/04/2023]
Abstract
Mutations of rat sarcoma virus (RAS) oncogenes (HRAS, KRAS and NRAS) can contribute to the development of cancers and genetic disorders (RASopathies). The spatiotemporal organization of RAS is an important property that warrants further investigation. In order to function, wild-type or oncogenic mutants of RAS must be localized to the inner leaflet of the plasma membrane (PM), which is driven by interactions between their C-terminal membrane-anchoring domains and PM lipids. The isoform-specific RAS-lipid interactions promote the formation of nanoclusters on the PM. As main sites for effector recruitment, these nanoclusters are biologically important. Since the spatial distribution of lipids is sensitive to changing environments, such as mechanical and electrical perturbations, RAS nanoclusters act as transducers to convert external stimuli to intracellular mitogenic signalling. As such, effective inhibition of RAS oncogenesis requires consideration of the complex interplay between RAS nanoclusters and various cell surface and extracellular stimuli. In this review, we discuss in detail how, by sorting specific lipids in the PM, RAS nanoclusters act as transducers to convert external stimuli into intracellular signalling.
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Affiliation(s)
- Yong Zhou
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston, McGovern Medical School, TX, USA
- Graduate School of Biomedical Sciences, University of Texas MD Anderson Cancer Center and University of Texas Health Science Center, TX, USA
| | - John F Hancock
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston, McGovern Medical School, TX, USA
- Graduate School of Biomedical Sciences, University of Texas MD Anderson Cancer Center and University of Texas Health Science Center, TX, USA
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14
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Remodeling of the Plasma Membrane by Surface-Bound Protein Monomers and Oligomers: The Critical Role of Intrinsically Disordered Regions. J Membr Biol 2022; 255:651-663. [PMID: 35930019 PMCID: PMC9718270 DOI: 10.1007/s00232-022-00256-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Accepted: 07/07/2022] [Indexed: 12/24/2022]
Abstract
The plasma membrane (PM) of cells is a dynamic structure whose morphology and composition is in constant flux. PM morphologic changes are particularly relevant for the assembly and disassembly of signaling platforms involving surface-bound signaling proteins, as well as for many other mechanochemical processes that occur at the PM surface. Surface-bound membrane proteins (SBMP) require efficient association with the PM for their function, which is often achieved by the coordinated interactions of intrinsically disordered regions (IDRs) and globular domains with membrane lipids. This review focuses on the role of IDR-containing SBMPs in remodeling the composition and curvature of the PM. The ability of IDR-bearing SBMPs to remodel the Gaussian and mean curvature energies of the PM is intimately linked to their ability to sort subsets of phospholipids into nanoclusters. We therefore discuss how IDRs of many SBMPs encode lipid-binding specificity or facilitate cluster formation, both of which increase their membrane remodeling capacity, and how SBMP oligomers alter membrane shape by monolayer surface area expansion and molecular crowding.
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15
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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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16
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Volmar AY, Guterres H, Zhou H, Reid D, Pavlopoulos S, Makowski L, Mattos C. Mechanisms of isoform-specific residue influence on GTP-bound HRas, KRas, and NRas. Biophys J 2022; 121:3616-3629. [PMID: 35794829 PMCID: PMC9617160 DOI: 10.1016/j.bpj.2022.07.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 05/04/2022] [Accepted: 07/01/2022] [Indexed: 11/16/2022] Open
Abstract
HRas, KRas, and NRas are GTPases with a common set of effectors that control many cell-signaling pathways, including proliferation through Raf kinase. Their G-domains are nearly identical in sequence, with a few isoform-specific residues that have an effect on dynamics and biochemical properties. Here, we use accelerated molecular dynamics (aMD) simulations consistent with solution x-ray scattering experiments to elucidate mechanisms through which isoform-specific residues associated with each Ras isoform affects functionally important regions connected to the active site. HRas-specific residues cluster in loop 8 to stabilize the nucleotide-binding pocket, while NRas-specific residues on helix 3 directly affect the conformations of switch I and switch II. KRas, the most globally flexible of the isoforms, shows greatest fluctuations in the switch regions enhanced by a KRas-specific residue in loop 7 and a highly dynamic loop 8 region. The analysis of isoform-specific residue effects on Ras proteins is supported by NMR experiments and is consistent with previously published biochemical data.
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Affiliation(s)
- Alicia Y Volmar
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, Massachusetts
| | - Hugo Guterres
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, Massachusetts
| | - Hao Zhou
- Department of Electrical and Computing Engineering, Northeastern University, Boston, Massachusetts
| | - Derion Reid
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, Massachusetts
| | - Spiro Pavlopoulos
- Department of Pharmaceutical Sciences, Northeastern University, Boston, Massachusetts
| | - Lee Makowski
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, Massachusetts; Department of Bioengineering, Northeastern University, Boston, Massachusetts
| | - Carla Mattos
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, Massachusetts.
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17
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Nanoscopic Spatial Association between Ras and Phosphatidylserine on the Cell Membrane Studied with Multicolor Super Resolution Microscopy. Biomolecules 2022; 12:biom12081033. [PMID: 35892343 PMCID: PMC9332490 DOI: 10.3390/biom12081033] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2022] [Revised: 07/02/2022] [Accepted: 07/22/2022] [Indexed: 11/17/2022] Open
Abstract
Recent work suggests that Ras small GTPases interact with the anionic lipid phosphatidylserine (PS) in an isoform-specific manner, with direct implications for their biological functions. Studies on PS-Ras associations in cells, however, have relied on immuno-EM imaging of membrane sheets. To study their spatial relationships in intact cells, we have combined the use of Lact-C2-GFP, a biosensor for PS, with multicolor super resolution imaging based on DNA-PAINT. At ~20 nm spatial resolution, the resulting super resolution images clearly show the nonuniform molecular distribution of PS on the cell membrane and its co-enrichment with caveolae, as well as with unidentified membrane structures. Two-color imaging followed by spatial analysis shows that KRas-G12D and HRas-G12V both co-enrich with PS in model U2OS cells, confirming previous observations, yet exhibit clear differences in their association patterns. Whereas HRas-G12V is almost always co-enriched with PS, KRas-G12D is strongly co-enriched with PS in about half of the cells, with the other half exhibiting a more moderate association. In addition, perturbations to the actin cytoskeleton differentially impact PS association with the two Ras isoforms. These results suggest that PS-Ras association is context-dependent and demonstrate the utility of multiplexed super resolution imaging in defining the complex interplay between Ras and the membrane.
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18
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Pavic K, Chippalkatti R, Abankwa D. Drug targeting opportunities en route to Ras nanoclusters. Adv Cancer Res 2022; 153:63-99. [PMID: 35101236 DOI: 10.1016/bs.acr.2021.07.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Disruption of the native membrane organization of Ras by the farnesyltransferase inhibitor tipifarnib in the late 1990s constituted the first indirect approach to drug target Ras. Since then, our understanding of how dynamically Ras shuttles between subcellular locations has changed significantly. Ras proteins have to arrive at the plasma membrane for efficient MAPK-signal propagation. On the plasma membrane Ras proteins are organized into isoform specific proteo-lipid assemblies called nanocluster. Recent evidence suggests that Ras nanocluster have a specific lipid composition, which supports the recruitment of effectors such as Raf. Conversely, effectors possess lipid-recognition motifs, which appear to serve as co-incidence detectors for the lipid domain of a given Ras isoform. Evidence suggests that dimeric Raf proteins then co-assemble dimeric Ras in an immobile complex, thus forming the minimal unit of an active nanocluster. Here we review established and novel trafficking chaperones and trafficking factors of Ras, along with the set of lipid and protein modulators of Ras nanoclustering. We highlight drug targeting approaches and opportunities against these determinants of functional Ras membrane organization. Finally, we reflect on implications for Ras signaling in polarized cells, such as epithelia, which are a common origin of tumorigenesis.
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Affiliation(s)
- Karolina Pavic
- Cancer Cell Biology and Drug Discovery Group, Department of Life Sciences and Medicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Rohan Chippalkatti
- Cancer Cell Biology and Drug Discovery Group, Department of Life Sciences and Medicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Daniel Abankwa
- Cancer Cell Biology and Drug Discovery Group, Department of Life Sciences and Medicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg.
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19
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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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20
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Prakash P, Gorfe AA. Determinants of Membrane Orientation Dynamics in Lipid-Modified Small GTPases. JACS AU 2022; 2:128-135. [PMID: 35098229 PMCID: PMC8790735 DOI: 10.1021/jacsau.1c00426] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Indexed: 05/30/2023]
Abstract
The transient membrane engagement and reorientation of the soluble catalytic domain of Ras proteins has emerged as an important modulator of their functions. However, there has been limited information on whether this phenomenon is applicable to other members of the Ras superfamily. To address this issue, we conducted long-time-scale atomistic molecular dynamics simulations (55 μs aggregate simulation time) on representatives of the Ras, Rho, and Arf family proteins that differ in sequence, lipid modification, and the rigidity of the linker between the lipid anchor and the catalytic G-domain. The results show that the concept of membrane reorientation is generalizable to most but not all members of the Ras superfamily. Specifically, C-terminally prenylated small GTPases that are anchored to membranes via a single flexible linker adopt multiple orientations, whereas those that are N-terminally myristoylated and harbor a rigid linker experience limited orientational dynamics. Combined with published reports on Ras proteins, these observations provide insights into the common principles and determinants of the orientational dynamics of lipidated small GTPases on membrane surfaces and offer new ways of thinking about the regulation and druggability of the Ras superfamily proteins.
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21
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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: 40] [Impact Index Per Article: 20.0] [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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22
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Wang X. Conformational Fluctuations in GTP-Bound K-Ras: A Metadynamics Perspective with Harmonic Linear Discriminant Analysis. J Chem Inf Model 2021; 61:5212-5222. [PMID: 34570515 DOI: 10.1021/acs.jcim.1c00844] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Biomacromolecules often undergo significant conformational rearrangements during function. In proteins, these motions typically consist in nontrivial, concerted rearrangement of multiple flexible regions. Mechanistic, thermodynamics, and kinetic predictions can be obtained via molecular dynamics simulations, provided that the simulation time is at least comparable to the relevant time scale of the process of interest. Because of the substantial computational cost, however, plain MD simulations often have difficulty in obtaining sufficient statistics for converged estimates, requiring the use of more-advanced techniques. Central in many enhanced sampling methods is the definition of a small set of relevant degrees of freedom (collective variables) that are able to describe the transitions between different metastable states of the system. The harmonic linear discriminant analysis (HLDA) has been shown to be useful for constructing low-dimensional collective variables in various complex systems. Here, we apply HLDA to study the free-energy landscape of a monomeric protein around its native state. More precisely, we study the K-Ras protein bound to GTP, focusing on two flexible loops and on the region associated with oncogenic mutations. We perform microsecond-long biased simulations on the wild type and on G12C, G12D, G12 V mutants, describe the resulting free-energy landscapes, and compare our predictions with previous experimental and computational studies. The fast interconversion between open and closed macroscopic states and their similar thermodynamic stabilities are observed. The mutation-induced effects include the alternations of the relative stabilities of different conformational states and the introduction of many microscopic metastable states. Together, our results demonstrate the applicability of the HLDA-based protocol for the conformational sampling of multiple flexible regions in folded proteins.
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Affiliation(s)
- Xiaohui Wang
- Beijing National Laboratory for Molecular Sciences, Institute of Theoretical and Computational Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
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23
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Mysore VP, Zhou ZW, Ambrogio C, Li L, Kapp JN, Lu C, Wang Q, Tucker MR, Okoro JJ, Nagy-Davidescu G, Bai X, Plückthun A, Jänne PA, Westover KD, Shan Y, Shaw DE. A structural model of a Ras-Raf signalosome. Nat Struct Mol Biol 2021; 28:847-857. [PMID: 34625747 PMCID: PMC8643099 DOI: 10.1038/s41594-021-00667-6] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Accepted: 08/25/2021] [Indexed: 01/29/2023]
Abstract
The protein K-Ras functions as a molecular switch in signaling pathways regulating cell growth. In the human mitogen-activated protein kinase (MAPK) pathway, which is implicated in many cancers, multiple K-Ras proteins are thought to assemble at the cell membrane with Ras effector proteins from the Raf family. Here we propose an atomistic structural model for such an assembly. Our starting point was an asymmetric guanosine triphosphate-mediated K-Ras dimer model, which we generated using unbiased molecular dynamics simulations and verified with mutagenesis experiments. Adding further K-Ras monomers in a head-to-tail fashion led to a compact helical assembly, a model we validated using electron microscopy and cell-based experiments. This assembly stabilizes K-Ras in its active state and presents composite interfaces to facilitate Raf binding. Guided by existing experimental data, we then positioned C-Raf, the downstream kinase MEK1 and accessory proteins (Galectin-3 and 14-3-3σ) on and around the helical assembly. The resulting Ras-Raf signalosome model offers an explanation for a large body of data on MAPK signaling.
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Affiliation(s)
| | - Zhi-Wei Zhou
- Departments of Biochemistry and Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Chiara Ambrogio
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA
- Department of Molecular Biotechnology and Health Sciences, Molecular Biotechnology Center, University of Turin, Turin, Italy
| | - Lianbo Li
- Departments of Biochemistry and Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Jonas N Kapp
- Department of Biochemistry, University of Zürich, Zürich, Switzerland
| | - Chunya Lu
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Department of Respiratory Medicine, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Qi Wang
- D. E. Shaw Research, New York, NY, USA
| | | | - Jeffrey J Okoro
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA
| | | | - Xiaochen Bai
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Andreas Plückthun
- Department of Biochemistry, University of Zürich, Zürich, Switzerland
| | - Pasi A Jänne
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA
- Belfer Center for Applied Cancer Science, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Kenneth D Westover
- Departments of Biochemistry and Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | | | - David E Shaw
- D. E. Shaw Research, New York, NY, USA.
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA.
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24
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Franz M, Mörchen B, Degenhart C, Gülden D, Shkura O, Wolters D, Koch U, Klebl B, Stoll R, Helfrich I, Scherkenbeck J. Sequence-Selective Covalent CaaX-Box Receptors Prevent Farnesylation of Oncogenic Ras Proteins and Impact MAPK/PI3 K Signaling. ChemMedChem 2021; 16:2504-2514. [PMID: 33899342 PMCID: PMC8453727 DOI: 10.1002/cmdc.202100167] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Indexed: 01/21/2023]
Abstract
Oncogenic Ras proteins are implicated in the most common life-threatening cancers. Despite intense research over the past two decades, the progress towards small-molecule inhibitors has been limited. One reason for this failure is that Ras proteins interact with their effectors only via protein-protein interactions, which are notoriously difficult to address with small organic molecules. Herein we describe an alternative strategy, which prevents farnesylation and subsequent membrane insertion, a prerequisite for the activation of Ras proteins. Our approach is based on sequence-selective supramolecular receptors which bind to the C-terminal farnesyl transferase recognition unit of Ras and Rheb proteins and covalently modify the essential cysteine in the so-called CaaX-box.
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Affiliation(s)
- Matthias Franz
- Faculty of Mathematics and Natural SciencesUniversity of Wuppertal42119WuppertalGermany
| | - Britta Mörchen
- Vascular Oncology & MetastasisUniversity Hospital Essen45147EssenGermany
| | | | - Daniel Gülden
- Faculty of Mathematics and Natural SciencesUniversity of Wuppertal42119WuppertalGermany
| | - Oleksandr Shkura
- Faculty of Chemistry and BiochemistryRuhr-University Bochum44780BochumGermany
| | - Dirk Wolters
- Faculty of Chemistry and BiochemistryRuhr-University Bochum44780BochumGermany
| | - Uwe Koch
- Lead Discovery Center GmbH44227DortmundGermany
| | - Bert Klebl
- Lead Discovery Center GmbH44227DortmundGermany
| | - Raphael Stoll
- Faculty of Chemistry and BiochemistryRuhr-University Bochum44780BochumGermany
| | - Iris Helfrich
- Vascular Oncology & MetastasisUniversity Hospital Essen45147EssenGermany
| | - Jürgen Scherkenbeck
- Faculty of Mathematics and Natural SciencesUniversity of Wuppertal42119WuppertalGermany
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25
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Intrinsically disordered proteins and membranes: a marriage of convenience for cell signalling? Biochem Soc Trans 2021; 48:2669-2689. [PMID: 33155649 PMCID: PMC7752083 DOI: 10.1042/bst20200467] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Revised: 10/05/2020] [Accepted: 10/08/2020] [Indexed: 02/07/2023]
Abstract
The structure-function paradigm has guided investigations into the molecules involved in cellular signalling for decades. The peripheries of this paradigm, however, start to unravel when considering the co-operation between proteins and the membrane in signalling processes. Intrinsically disordered regions hold distinct advantages over folded domains in terms of their binding promiscuity, sensitivity to their particular environment and their ease of modulation through post-translational modifications. Low sequence complexity and bias towards charged residues are also favourable for the multivalent electrostatic interactions that occur at the surfaces of lipid bilayers. This review looks at the principles behind the successful marriage between protein disorder and membranes in addition to the role of this partnership in modifying and regulating signalling in cellular processes. The HVR (hypervariable region) of small GTPases is highlighted as a well-studied example of the nuanced role a short intrinsically disordered region can play in the fine-tuning of signalling pathways.
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26
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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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27
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Ras Variant Biology and Contributions to Human Disease. METHODS IN MOLECULAR BIOLOGY (CLIFTON, N.J.) 2021; 2262:3-18. [PMID: 33977468 DOI: 10.1007/978-1-0716-1190-6_1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Analysis of cancer and RASopathy genetic databases reveals that ~19% of all cancer cases and ~4% of developmental disorders contain Ras mutations. Ras isoform and mutation variants differentially contribute to these diseases and provide an opportunity for deeper understanding of Ras function. The putative mechanisms underpinning these differences, new approaches that are being applied, and some of the key questions and challenges that remain are discussed.
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28
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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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29
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Kiel C, Matallanas D, Kolch W. The Ins and Outs of RAS Effector Complexes. Biomolecules 2021; 11:236. [PMID: 33562401 PMCID: PMC7915224 DOI: 10.3390/biom11020236] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2021] [Revised: 01/31/2021] [Accepted: 02/03/2021] [Indexed: 12/12/2022] Open
Abstract
RAS oncogenes are among the most commonly mutated proteins in human cancers. They regulate a wide range of effector pathways that control cell proliferation, survival, differentiation, migration and metabolic status. Including aberrations in these pathways, RAS-dependent signaling is altered in more than half of human cancers. Targeting mutant RAS proteins and their downstream oncogenic signaling pathways has been elusive. However, recent results comprising detailed molecular studies, large scale omics studies and computational modeling have painted a new and more comprehensive portrait of RAS signaling that helps us to understand the intricacies of RAS, how its physiological and pathophysiological functions are regulated, and how we can target them. Here, we review these efforts particularly trying to relate the detailed mechanistic studies with global functional studies. We highlight the importance of computational modeling and data integration to derive an actionable understanding of RAS signaling that will allow us to design new mechanism-based therapies for RAS mutated cancers.
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Affiliation(s)
- Christina Kiel
- Systems Biology Ireland, School of Medicine, University College Dublin, Dublin 4, Ireland; (C.K.); (D.M.)
- UCD Charles Institute of Dermatology, School of Medicine, University College Dublin, Dublin 4, Ireland
| | - David Matallanas
- Systems Biology Ireland, School of Medicine, University College Dublin, Dublin 4, Ireland; (C.K.); (D.M.)
| | - Walter Kolch
- Systems Biology Ireland, School of Medicine, University College Dublin, Dublin 4, Ireland; (C.K.); (D.M.)
- Conway Institute of Biomolecular & Biomedical Research, University College Dublin, Dublin 4, Ireland
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30
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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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31
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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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32
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Kattan WE, Hancock JF. RAS Function in cancer cells: translating membrane biology and biochemistry into new therapeutics. Biochem J 2020; 477:2893-2919. [PMID: 32797215 PMCID: PMC7891675 DOI: 10.1042/bcj20190839] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 07/20/2020] [Accepted: 07/22/2020] [Indexed: 02/07/2023]
Abstract
The three human RAS proteins are mutated and constitutively activated in ∼20% of cancers leading to cell growth and proliferation. For the past three decades, many attempts have been made to inhibit these proteins with little success. Recently; however, multiple methods have emerged to inhibit KRAS, the most prevalently mutated isoform. These methods and the underlying biology will be discussed in this review with a special focus on KRAS-plasma membrane interactions.
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Affiliation(s)
- Walaa E. Kattan
- Department of Integrative Biology and Pharmacology, McGovern Medical School University of Texas Health Science Center at Houston, TX 77030, USA
- The University of Texas MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, TX 77030, USA
| | - John F. Hancock
- Department of Integrative Biology and Pharmacology, McGovern Medical School University of Texas Health Science Center at Houston, TX 77030, USA
- The University of Texas MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, TX 77030, USA
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33
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Prakash P. A regulatory role of membrane by direct modulation of the catalytic kinase domain. Small GTPases 2020; 12:246-256. [PMID: 32663062 DOI: 10.1080/21541248.2020.1788886] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Cell membrane modulates the function and activity of specific proteins and acts more than just a non-specific scaffolding machinery. In this review, I focus on studies that highlight a direct membrane-mediated modulation of the catalytic kinase domain of a variety of kinases thereby regulating the kinase activity. It emerges that membrane provides a second level of regulation once kinase domain is relieved of its inactive auto-inhibitory state. For the first time a generalized regulatory role of membrane is proposed that governs the kinase activity by modulating the catalytic kinase domain. Striking similarities among a variety of multi-domain kinases as well as single-domain lipidated enzymes such as RAS proteins are presented.
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Affiliation(s)
- Priyanka Prakash
- Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston, Houston, TX, USA
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34
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Abstract
RAS was identified as a human oncogene in the early 1980s and subsequently found to be mutated in nearly 30% of all human cancers. More importantly, RAS plays a central role in driving tumor development and maintenance. Despite decades of effort, there remain no FDA approved drugs that directly inhibit RAS. The prevalence of RAS mutations in cancer and the lack of effective anti-RAS therapies stem from RAS' core role in growth factor signaling, unique structural features, and biochemistry. However, recent advances have brought promising new drugs to clinical trials and shone a ray of hope in the field. Here, we will exposit the details of RAS biology that illustrate its key role in cell signaling and shed light on the difficulties in therapeutically targeting RAS. Furthermore, past and current efforts to develop RAS inhibitors will be discussed in depth.
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Affiliation(s)
- J Matthew Rhett
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Hollings Cancer Center, Medical University of South Carolina, Charleston, SC, United States; Ralph H. Johnson VA Medical Center, Charleston, SC, United States
| | - Imran Khan
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Hollings Cancer Center, Medical University of South Carolina, Charleston, SC, United States; Ralph H. Johnson VA Medical Center, Charleston, SC, United States
| | - John P O'Bryan
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Hollings Cancer Center, Medical University of South Carolina, Charleston, SC, United States; Ralph H. Johnson VA Medical Center, Charleston, SC, United States.
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35
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Chen K, Shang Z, Dai AL, Dai PL. Novel PI3K/Akt/mTOR pathway inhibitors plus radiotherapy: Strategy for non-small cell lung cancer with mutant RAS gene. Life Sci 2020; 255:117816. [PMID: 32454155 DOI: 10.1016/j.lfs.2020.117816] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 05/07/2020] [Accepted: 05/16/2020] [Indexed: 02/07/2023]
Abstract
Non-small cell lung cancer (NSCLC) with RAS -mutant gene has been the most difficult obstacle to overcome. Over 25% of muted lung adenocarcinomas have RAS mutation. The prognosis of NSCLC patients with RAS-mutant genes is always poor because there is no effective drug to suppress RAS-mutant genes. NSCLC patients with RAS-mutant usually develop resistance to radiotherapy and chemotherapy, which in some cases leads to a 5-10% survival rate for non-small cell lung cancer (NSCLC). As little clinical symptom of NSCLC was presented at its early stages, thus it always brings in disappointing treatment outcome. Currently, NSCLC presents the highest morbidity and mortality all over the world. The combination of PI3K/AKT/mTOR pathway inhibitors with radiotherapy is a novel strategy to improve radiosensitivity and therapeutic outcome of NSCLC with a RAS-mutant gene. There have been many preclinical studies and clinical trials on the effect of PI3K/AKT/mTOR pathway inhibitors combined with radiotherapy in NSCLC with a RAS-mutant gene have been reported in the past years. This review provides current knowledge of the combination of PI3K/Akt/mTOR pathway inhibitors with radiotherapy, which prove to be a significant improvement for the treatment of NSCLC patients with RAS mutations and will benefit NSCLC patients with RAS mutations.
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Affiliation(s)
- Kai Chen
- The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou 325027, China
| | - Zhongjun Shang
- Third Affiliated Hospital of Kunming Medical University, Tumor Hospital of Yunnan Province, Kunming 650118, China
| | - Ai-Lin Dai
- Kunming Medical University Haiyuan School, Kunming 650100, China; Maternal and Child Health and Family Planning Service Center of Wenshan state, 663000, China
| | - Pei-Ling Dai
- Third Affiliated Hospital of Kunming Medical University, Tumor Hospital of Yunnan Province, Kunming 650118, China; Kunming Medical University, Kunming 650100, China.
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36
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Neale C, García AE. The Plasma Membrane as a Competitive Inhibitor and Positive Allosteric Modulator of KRas4B Signaling. Biophys J 2020; 118:1129-1141. [PMID: 32027820 PMCID: PMC7063485 DOI: 10.1016/j.bpj.2019.12.039] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 12/04/2019] [Accepted: 12/18/2019] [Indexed: 12/31/2022] Open
Abstract
Mutant Ras proteins are important drivers of human cancers, yet no approved drugs act directly on this difficult target. Over the last decade, the idea has emerged that oncogenic signaling can be diminished by molecules that drive Ras into orientations in which effector-binding interfaces are occluded by the cell membrane. To support this approach to drug discovery, we characterize the orientational preferences of membrane-bound K-Ras4B in 1.45-ms aggregate time of atomistic molecular dynamics simulations. Individual simulations probe active or inactive states of Ras on membranes with or without anionic lipids. We find that the membrane orientation of Ras is relatively insensitive to its bound guanine nucleotide and activation state but depends strongly on interactions with anionic phosphatidylserine lipids. These lipids slow Ras' translational and orientational diffusion and promote a discrete population in which small changes in orientation control Ras' competence to bind multiple regulator and effector proteins. Our results suggest that compound-directed conversion of constitutively active mutant Ras into functionally inactive forms may be accessible via subtle perturbations of Ras' orientational preferences at the membrane surface.
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Affiliation(s)
- Chris Neale
- Theoretical Biology and Biophysics, Los Alamos National Laboratory, Los Alamos, New Mexico
| | - Angel E García
- Center for Nonlinear Studies, Los Alamos National Laboratory, Los Alamos, New Mexico.
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37
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Marcus K, Mattos C. Water in Ras Superfamily Evolution. J Comput Chem 2020; 41:402-414. [PMID: 31483874 DOI: 10.1002/jcc.26060] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 07/17/2019] [Accepted: 08/16/2019] [Indexed: 01/14/2023]
Abstract
The Ras GTPase superfamily of proteins coordinates a diverse set of cellular outcomes, including cell morphology, vesicle transport, and cell proliferation. Primary amino acid sequence analysis has identified Specificity determinant positions (SDPs) that drive diversified functions specific to the Ras, Rho, Rab, and Arf subfamilies (Rojas et al. 2012, J Cell Biol 196:189-201). The inclusion of water molecules in structural and functional adaptation is likely to be a major response to the selection pressures that drive evolution, yet hydration patterns are not included in phylogenetic analysis. This article shows that conserved crystallographic water molecules coevolved with SDP residues in the differentiation of proteins within the Ras superfamily of small GTPases. The patterns of water conservation between protein subfamilies parallel those of sequence-based evolutionary trees. Thus, hydration patterns have the potential to help elucidate functional significance in the evolution of amino acid residues observed in phylogenetic analysis of homologous proteins. © 2019 Wiley Periodicals, Inc.
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Affiliation(s)
- Kendra Marcus
- Department of Chemistry and Chemical Biology, Northeastern University, 360 Huntington Ave, Boston, Massachusetts, 02115
| | - Carla Mattos
- Department of Chemistry and Chemical Biology, Northeastern University, 360 Huntington Ave, Boston, Massachusetts, 02115
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38
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Khan I, Rhett JM, O'Bryan JP. Therapeutic targeting of RAS: New hope for drugging the "undruggable". BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2020; 1867:118570. [PMID: 31678118 PMCID: PMC6937383 DOI: 10.1016/j.bbamcr.2019.118570] [Citation(s) in RCA: 68] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 10/01/2019] [Accepted: 10/14/2019] [Indexed: 12/18/2022]
Abstract
RAS is the most frequently mutated oncogene in cancer and a critical driver of oncogenesis. Therapeutic targeting of RAS has been a goal of cancer research for more than 30 years due to its essential role in tumor formation and maintenance. Yet the quest to inhibit this challenging foe has been elusive. Although once considered "undruggable", the struggle to directly inhibit RAS has seen recent success with the development of pharmacological agents that specifically target the KRAS(G12C) mutant protein, which include the first direct RAS inhibitor to gain entry to clinical trials. However, the limited applicability of these inhibitors to G12C-mutant tumors demands further efforts to identify more broadly efficacious RAS inhibitors. Understanding allosteric influences on RAS may open new avenues to inhibit RAS. Here, we provide a brief overview of RAS biology and biochemistry, discuss the allosteric regulation of RAS, and summarize the various approaches to develop RAS inhibitors.
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Affiliation(s)
- Imran Khan
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Hollings Cancer Center, Medical University of South Carolina, Charleston, SC 29425, United States of America; Ralph H. Johnson VA Medical Center, Charleston, SC 29401, United States of America
| | - J Matthew Rhett
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Hollings Cancer Center, Medical University of South Carolina, Charleston, SC 29425, United States of America; Ralph H. Johnson VA Medical Center, Charleston, SC 29401, United States of America
| | - John P O'Bryan
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Hollings Cancer Center, Medical University of South Carolina, Charleston, SC 29425, United States of America; Ralph H. Johnson VA Medical Center, Charleston, SC 29401, United States of America.
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39
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Gorfe AA, Sligar SG. Membrane-Bound Ras as a Conformational Clock. Biophys J 2020; 118:991-993. [PMID: 32023437 DOI: 10.1016/j.bpj.2020.01.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Accepted: 01/14/2020] [Indexed: 01/18/2023] Open
Affiliation(s)
- Alemayehu A Gorfe
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, Texas.
| | - Stephen G Sligar
- Department of Biochemistry, University of Illinois, Urbana, Illinois.
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40
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Schuster R, Anton V, Simões T, Altin S, den Brave F, Hermanns T, Hospenthal M, Komander D, Dittmar G, Dohmen RJ, Escobar-Henriques M. Dual role of a GTPase conformational switch for membrane fusion by mitofusin ubiquitylation. Life Sci Alliance 2020; 3:e201900476. [PMID: 31857350 PMCID: PMC6925385 DOI: 10.26508/lsa.201900476] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 12/11/2019] [Accepted: 12/11/2019] [Indexed: 12/13/2022] Open
Abstract
Mitochondria are essential organelles whose function is upheld by their dynamic nature. This plasticity is mediated by large dynamin-related GTPases, called mitofusins in the case of fusion between two mitochondrial outer membranes. Fusion requires ubiquitylation, attached to K398 in the yeast mitofusin Fzo1, occurring in atypical and conserved forms. Here, modelling located ubiquitylation to α4 of the GTPase domain, a critical helix in Ras-mediated events. Structure-driven analysis revealed a dual role of K398. First, it is required for GTP-dependent dynamic changes of α4. Indeed, mutations designed to restore the conformational switch, in the absence of K398, rescued wild-type-like ubiquitylation on Fzo1 and allowed fusion. Second, K398 is needed for Fzo1 recognition by the pro-fusion factors Cdc48 and Ubp2. Finally, the atypical ubiquitylation pattern is stringently required bilaterally on both involved mitochondria. In contrast, exchange of the conserved pattern with conventional ubiquitin chains was not sufficient for fusion. In sum, α4 lysines from both small and large GTPases could generally have an electrostatic function for membrane interaction, followed by posttranslational modifications, thus driving membrane fusion events.
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Affiliation(s)
- Ramona Schuster
- Institute for Genetics, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Vincent Anton
- Institute for Genetics, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Tânia Simões
- Institute for Genetics, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Selver Altin
- Institute for Genetics, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Fabian den Brave
- Department of Molecular Cell Biology, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Thomas Hermanns
- Institute for Genetics, University of Cologne, Cologne, Germany
| | - Manuela Hospenthal
- Institute of Molecular Biology and Biophysics, Eidgenössische Technische Hochschule Zürich, Zürich, Switzerland
| | - David Komander
- Medical Research Council Laboratory of Molecular Biology, Cambridge, UK
- Ubiquitin Signalling Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
- Department of Medical Biology, The University of Melbourne, Melbourne, Australia
| | - Gunnar Dittmar
- Proteomics of Cellular Signalling, Luxembourg Institute of Health, Strassen, Luxembourg
| | - R Jürgen Dohmen
- Institute for Genetics, University of Cologne, Cologne, Germany
| | - Mafalda Escobar-Henriques
- Institute for Genetics, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
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41
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Nussinov R, Tsai CJ, Jang H. Does Ras Activate Raf and PI3K Allosterically? Front Oncol 2019; 9:1231. [PMID: 31799192 PMCID: PMC6874141 DOI: 10.3389/fonc.2019.01231] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Accepted: 10/28/2019] [Indexed: 12/11/2022] Open
Abstract
The mechanism through which oncogenic Ras activates its effectors is vastly important to resolve. If allostery is at play, then targeting allosteric pathways could help in quelling activation of MAPK (Raf/MEK/ERK) and PI3K (PI3K/Akt/mTOR) cell proliferation pathways. On the face of it, allosteric activation is reasonable: Ras binding perturbs the conformational ensembles of its effectors. Here, however, we suggest that at least for Raf, PI3K, and NORE1A (RASSF5), that is unlikely. Raf's long disordered linker dampens effective allosteric activation. Instead, we suggest that the high-affinity Ras–Raf binding relieves Raf's autoinhibition, shifting Raf's ensemble from the inactive to the nanocluster-mediated dimerized active state, as Ras also does for NORE1A. PI3K is recruited and allosterically activated by RTK (e.g., EGFR) at the membrane. Ras restrains PI3K's distribution and active site orientation. It stabilizes and facilitates PIP2 binding at the active site and increases the PI3K residence time at the membrane. Thus, RTKs allosterically activate PI3Kα; however, merging their action with Ras accomplishes full activation. Here we review their activation mechanisms in this light and draw attention to implications for their pharmacology.
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Affiliation(s)
- Ruth Nussinov
- Cancer and Inflammation Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, National Cancer Institute at Frederick, Frederick, MD, United States.,Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Chung-Jung Tsai
- Cancer and Inflammation Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, National Cancer Institute at Frederick, Frederick, MD, United States
| | - Hyunbum Jang
- Cancer and Inflammation Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, National Cancer Institute at Frederick, Frederick, MD, United States
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42
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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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43
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Roy NS, Jian X, Soubias O, Zhai P, Hall JR, Dagher JN, Coussens NP, Jenkins LM, Luo R, Akpan IO, Hall MD, Byrd RA, Yohe ME, Randazzo PA. Interaction of the N terminus of ADP-ribosylation factor with the PH domain of the GTPase-activating protein ASAP1 requires phosphatidylinositol 4,5-bisphosphate. J Biol Chem 2019; 294:17354-17370. [PMID: 31591270 DOI: 10.1074/jbc.ra119.009269] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Revised: 10/02/2019] [Indexed: 12/15/2022] Open
Abstract
Arf GAP with Src homology 3 domain, ankyrin repeat, and pleckstrin homology (PH) domain 1 (ASAP1) is a multidomain GTPase-activating protein (GAP) for ADP-ribosylation factor (ARF)-type GTPases. ASAP1 affects integrin adhesions, the actin cytoskeleton, and invasion and metastasis of cancer cells. ASAP1's cellular function depends on its highly-regulated and robust ARF GAP activity, requiring both the PH and the ARF GAP domains of ASAP1, and is modulated by phosphatidylinositol 4,5-bisphosphate (PIP2). The mechanistic basis of PIP2-stimulated GAP activity is incompletely understood. Here, we investigated whether PIP2 controls binding of the N-terminal extension of ARF1 to ASAP1's PH domain and thereby regulates its GAP activity. Using [Δ17]ARF1, lacking the N terminus, we found that PIP2 has little effect on ASAP1's activity. A soluble PIP2 analog, dioctanoyl-PIP2 (diC8PIP2), stimulated GAP activity on an N terminus-containing variant, [L8K]ARF1, but only marginally affected activity on [Δ17]ARF1. A peptide comprising residues 2-17 of ARF1 ([2-17]ARF1) inhibited GAP activity, and PIP2-dependently bound to a protein containing the PH domain and a 17-amino acid-long interdomain linker immediately N-terminal to the first β-strand of the PH domain. Point mutations in either the linker or the C-terminal α-helix of the PH domain decreased [2-17]ARF1 binding and GAP activity. Mutations that reduced ARF1 N-terminal binding to the PH domain also reduced the effect of ASAP1 on cellular actin remodeling. Mutations in the ARF N terminus that reduced binding also reduced GAP activity. We conclude that PIP2 regulates binding of ASAP1's PH domain to the ARF1 N terminus, which may partially regulate GAP activity.
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Affiliation(s)
- Neeladri Sekhar Roy
- Laboratory of Cellular and Molecular Biology, Center for Cancer Research, NCI, National Institutes of Health, Bethesda, Maryland 20892
| | - Xiaoying Jian
- Laboratory of Cellular and Molecular Biology, Center for Cancer Research, NCI, National Institutes of Health, Bethesda, Maryland 20892
| | - Olivier Soubias
- Structural Biophysics Laboratory, Center for Cancer Research, NCI, National Institutes of Health, Frederick, Maryland 21702
| | - Peng Zhai
- Laboratory of Cellular and Molecular Biology, Center for Cancer Research, NCI, National Institutes of Health, Bethesda, Maryland 20892
| | - Jessica R Hall
- Chemical Genomics Center, National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, Maryland 20892
| | - Jessica N Dagher
- Chemical Genomics Center, National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, Maryland 20892
| | - Nathan P Coussens
- Chemical Genomics Center, National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, Maryland 20892
| | - Lisa M Jenkins
- Laboratory of Cell Biology, Center for Cancer Research, NCI, National Institutes of Health, Bethesda, Maryland 20892
| | - Ruibai Luo
- Laboratory of Cellular and Molecular Biology, Center for Cancer Research, NCI, National Institutes of Health, Bethesda, Maryland 20892
| | - Itoro O Akpan
- Laboratory of Cellular and Molecular Biology, Center for Cancer Research, NCI, National Institutes of Health, Bethesda, Maryland 20892
| | - Matthew D Hall
- Chemical Genomics Center, National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, Maryland 20892
| | - R Andrew Byrd
- Structural Biophysics Laboratory, Center for Cancer Research, NCI, National Institutes of Health, Frederick, Maryland 21702
| | - Marielle E Yohe
- Laboratory of Cellular and Molecular Biology, Center for Cancer Research, NCI, National Institutes of Health, Bethesda, Maryland 20892 .,Pediatric Oncology Branch, Center for Cancer Research, NCI, National Institutes of Health, Bethesda, Maryland 20892
| | - Paul A Randazzo
- Laboratory of Cellular and Molecular Biology, Center for Cancer Research, NCI, National Institutes of Health, Bethesda, Maryland 20892
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44
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Barklis E, Stephen AG, Staubus AO, Barklis RL, Alfadhli A. Organization of Farnesylated, Carboxymethylated KRAS4B on Membranes. J Mol Biol 2019; 431:3706-3717. [PMID: 31330153 PMCID: PMC6733658 DOI: 10.1016/j.jmb.2019.07.025] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 07/10/2019] [Accepted: 07/12/2019] [Indexed: 11/24/2022]
Abstract
Mutations of the Ras proteins HRAS, KRAS4A, KRAS4B, and NRAS are associated with a high percentage of all human cancers. The proteins are composed of highly homologous N-terminal catalytic or globular domains, plus C-terminal hypervariable regions (HVRs). Post-translational modifications of all RAS HVRs helps target RAS proteins to cellular membrane locations where they perform their signaling functions. For the predominant KRAS4 isoform, KRAS4B, post-translational farnesylation and carboxymethylation, along with a patch of HVR basic residues help foster membrane binding. Recent investigations implicate membrane-bound RAS dimers, oligomers, and nanoclusters as landing pads for effector proteins that relay RAS signals. The details of these RAS signaling platforms have not been elucidated completely, in part due to the difficulties in preparing modified proteins. We have employed properly farnesylated and carboxymethylated KRAS4B in lipid monolayer incubations to examine how the proteins assemble on membranes. Our results reveal novel insights into to how KRAS4B may organize on membranes.
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Affiliation(s)
- Eric Barklis
- Department of Molecular Microbiology and Immunology, Oregon Health & Sciences University, 3181 SW Sam Jackson Park Road, Portland, 97239, OR, USA.
| | - Andrew G Stephen
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, MD 21072, USA
| | - August O Staubus
- Department of Molecular Microbiology and Immunology, Oregon Health & Sciences University, 3181 SW Sam Jackson Park Road, Portland, 97239, OR, USA
| | - Robin Lid Barklis
- Department of Molecular Microbiology and Immunology, Oregon Health & Sciences University, 3181 SW Sam Jackson Park Road, Portland, 97239, OR, USA
| | - Ayna Alfadhli
- Department of Molecular Microbiology and Immunology, Oregon Health & Sciences University, 3181 SW Sam Jackson Park Road, Portland, 97239, OR, USA
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45
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Liang H, Mu H, Jean-Francois F, Lakshman B, Sarkar-Banerjee S, Zhuang Y, Zeng Y, Gao W, Zaske AM, Nissley DV, Gorfe AA, Zhao W, Zhou Y. Membrane curvature sensing of the lipid-anchored K-Ras small GTPase. Life Sci Alliance 2019; 2:e201900343. [PMID: 31296567 PMCID: PMC6625090 DOI: 10.26508/lsa.201900343] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 07/01/2019] [Accepted: 07/02/2019] [Indexed: 12/26/2022] Open
Abstract
Plasma membrane (PM) curvature defines cell shape and intracellular organelle morphologies and is a fundamental cell property. Growth/proliferation is more stimulated in flatter cells than the same cells in elongated shapes. PM-anchored K-Ras small GTPase regulates cell growth/proliferation and plays key roles in cancer. The lipid-anchored K-Ras form nanoclusters selectively enriched with specific phospholipids, such as phosphatidylserine (PS), for efficient effector recruitment and activation. K-Ras function may, thus, be sensitive to changing lipid distribution at membranes with different curvatures. Here, we used complementary methods to manipulate membrane curvature of intact/live cells, native PM blebs, and synthetic liposomes. We show that the spatiotemporal organization and signaling of an oncogenic mutant K-Ras G12V favor flatter membranes with low curvature. Our findings are consistent with the more stimulated growth/proliferation in flatter cells. Depletion of endogenous PS abolishes K-Ras G12V PM curvature sensing. In cells and synthetic bilayers, only mixed-chain PS species, but not other PS species tested, mediate K-Ras G12V membrane curvature sensing. Thus, K-Ras nanoclusters act as relay stations to convert mechanical perturbations to mitogenic signaling.
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Affiliation(s)
- Hong Liang
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Huanwen Mu
- School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore
| | - Frantz Jean-Francois
- National Cancer Institute RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Bindu Lakshman
- National Cancer Institute RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | | | - Yinyin Zhuang
- School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore
| | - Yongpeng Zeng
- School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore
| | - Weibo Gao
- School of Physics and Mathematical Science, Nanyang Technological University, Singapore
| | - Ana Maria Zaske
- Internal Medicine, Cardiology Division, University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Dwight V Nissley
- National Cancer Institute RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Alemayehu A Gorfe
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Wenting Zhao
- School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore
| | - Yong Zhou
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston, Houston, TX, USA
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46
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Muller MP, Jiang T, Sun C, Lihan M, Pant S, Mahinthichaichan P, Trifan A, Tajkhorshid E. Characterization of Lipid-Protein Interactions and Lipid-Mediated Modulation of Membrane Protein Function through Molecular Simulation. Chem Rev 2019; 119:6086-6161. [PMID: 30978005 PMCID: PMC6506392 DOI: 10.1021/acs.chemrev.8b00608] [Citation(s) in RCA: 133] [Impact Index Per Article: 26.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The cellular membrane constitutes one of the most fundamental compartments of a living cell, where key processes such as selective transport of material and exchange of information between the cell and its environment are mediated by proteins that are closely associated with the membrane. The heterogeneity of lipid composition of biological membranes and the effect of lipid molecules on the structure, dynamics, and function of membrane proteins are now widely recognized. Characterization of these functionally important lipid-protein interactions with experimental techniques is however still prohibitively challenging. Molecular dynamics (MD) simulations offer a powerful complementary approach with sufficient temporal and spatial resolutions to gain atomic-level structural information and energetics on lipid-protein interactions. In this review, we aim to provide a broad survey of MD simulations focusing on exploring lipid-protein interactions and characterizing lipid-modulated protein structure and dynamics that have been successful in providing novel insight into the mechanism of membrane protein function.
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Affiliation(s)
- Melanie P. Muller
- NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology
- Department of Biochemistry
- Center for Biophysics and Quantitative Biology
- College of Medicine
- University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Tao Jiang
- NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology
- Department of Biochemistry
- Center for Biophysics and Quantitative Biology
- University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Chang Sun
- NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology
- Department of Biochemistry
- University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Muyun Lihan
- NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology
- Department of Biochemistry
- Center for Biophysics and Quantitative Biology
- University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Shashank Pant
- NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology
- Department of Biochemistry
- Center for Biophysics and Quantitative Biology
- University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Paween Mahinthichaichan
- NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology
- Department of Biochemistry
- University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Anda Trifan
- NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology
- Department of Biochemistry
- Center for Biophysics and Quantitative Biology
- University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Emad Tajkhorshid
- NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology
- Department of Biochemistry
- Center for Biophysics and Quantitative Biology
- College of Medicine
- University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
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47
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Edler E, Stein M. Recognition and stabilization of geranylgeranylated human Rab5 by the GDP Dissociation Inhibitor (GDI). Small GTPases 2019; 10:227-242. [PMID: 29065764 PMCID: PMC6548291 DOI: 10.1080/21541248.2017.1371268] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Revised: 08/18/2017] [Accepted: 08/18/2017] [Indexed: 01/13/2023] Open
Abstract
The small GTPase Rab5 is the key regulator of early endosomal fusion. It is post-translationally modified by covalent attachment of two geranylgeranyl (GG) chains to adjacent cysteine residues of the C-terminal hypervariable region (HVR). The GDP dissociation inhibitor (GDI) recognizes membrane-associated Rab5(GDP) and serves to release it into the cytoplasm where it is kept in a soluble state. A detailed new structural and dynamic model for human Rab5(GDP) recognition and binding with human GDI at the early endosome membrane and in its dissociated state is presented. In the cytoplasm, the GDI protein accommodates the GG chains in a transient hydrophobic binding pocket. In solution, two different binding modes of the isoprenoid chains inserted into the hydrophobic pocket of the Rab5(GDP):GDI complex can be identified. This equilibrium between the two states helps to stabilize the protein-protein complex in solution. Interprotein contacts between the Rab5 switch regions and characteristic patches of GDI residues from the Rab binding platform (RBP) and the C-terminus coordinating region (CCR) reveal insight on the formation of such a stable complex. GDI binding to membrane-anchored Rab5(GDP) is initially mediated by the solvent accessible switch regions of the Rab-specific RBP. Formation of the membrane-associated Rab5(GDP):GDI complex induces a GDI reorientation to establish additional interactions with the Rab5 HVR. These results allow to devise a detailed structural model for the process of extraction of GG-Rab5(GDP) by GDI from the membrane and the dissociation from targeting factors and effector proteins prior to GDI binding.
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Affiliation(s)
- Eileen Edler
- Molecular Simulations and Design Group, Max Planck Institute for Dynamics of Complex Technical Systems, Magdeburg, Germany
| | - Matthias Stein
- Molecular Simulations and Design Group, Max Planck Institute for Dynamics of Complex Technical Systems, Magdeburg, Germany
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48
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Cao S, Chung S, Kim S, Li Z, Manor D, Buck M. K-Ras G-domain binding with signaling lipid phosphatidylinositol (4,5)-phosphate (PIP2): membrane association, protein orientation, and function. J Biol Chem 2019; 294:7068-7084. [PMID: 30792310 DOI: 10.1074/jbc.ra118.004021] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Revised: 12/12/2018] [Indexed: 12/14/2022] Open
Abstract
Ras genes potently drive human cancers, with mutated proto-oncogene GTPase KRAS4B (K-Ras4B) being the most abundant isoform. Targeted inhibition of oncogenic gene products is considered the "holy grail" of present-day cancer therapy, and recent discoveries of small-molecule KRas4B inhibitors were made thanks to a deeper understanding of the structure and dynamics of this GTPase. Because interactions with biological membranes are key for Ras function, Ras-lipid interactions have become a major focus, especially because such interactions evidently involve both the Ras C terminus for lipid anchoring and its G-protein domain. Here, using NMR spectroscopy and molecular dynamics simulations complemented by biophysical- and cell-biology assays, we investigated the interaction between K-Ras4B with the signaling lipid phosphatidylinositol (4,5)-phosphate (PIP2). We discovered that the β2 and β3 strands as well as helices 4 and 5 of the GTPase G-domain bind to PIP2 and identified the specific residues in these structural elements employed in these interactions, likely occurring in two K-Ras4B orientation states relative to the membrane. Importantly, we found that some of these residues known to be oncogenic when mutated (D47K, D92N, K104M, and D126N) are critical for K-Ras-mediated transformation of fibroblast cells, but do not substantially affect basal and assisted nucleotide hydrolysis and exchange. Moreover, the K104M substitution abolished localization of K-Ras to the plasma membrane. The findings suggest that specific G-domain residues can critically regulate Ras function by mediating interactions with membrane-associated PIP2 lipids; these insights that may inform the future design of therapeutic reagents targeting Ras activity.
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Affiliation(s)
- Shufen Cao
- From the Departments of Physiology and Biophysics
| | | | | | - Zhenlu Li
- From the Departments of Physiology and Biophysics
| | - Danny Manor
- Nutrition, .,Pharmacology, and.,the Case Comprehensive Cancer Center and
| | - Matthias Buck
- From the Departments of Physiology and Biophysics, .,the Case Comprehensive Cancer Center and.,Neurosciences, Case Western Reserve University, School of Medicine, Cleveland, Ohio 44106 and.,Center for Proteomics and Bioinformatics, Case Western Reserve University, School of Medicine, Cleveland, Ohio 44106
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49
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Three distinct regions of cRaf kinase domain interact with membrane. Sci Rep 2019; 9:2057. [PMID: 30765804 PMCID: PMC6375958 DOI: 10.1038/s41598-019-38770-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Accepted: 12/19/2018] [Indexed: 12/18/2022] Open
Abstract
Raf kinases are downstream effectors of small GTPase Ras. Mutations in Ras and Raf are associated with a variety of cancers and genetic disorders. Of the three Raf isoforms, cRaf is most frequently involved in tumor initiation by Ras. Cytosolic Raf is auto-inhibited and becomes active upon recruitment to the plasma membrane. Since the catalytic domain of Raf is its kinase domain, we ask the following: does the kinase domain of Raf has potential to interact with membrane and if yes, what role does the membrane interaction play? We present a model of cRaf kinase domain in complex with a heterogeneous membrane bilayer using atomistic molecular dynamics simulation. We show that the kinase domain of cRaf has three distinct membrane-interacting regions: a polybasic motif (R.RKTR) from the regulatory αC-helix, an aromatic/hydrophobic cluster from the N-terminal acidic region (NtA) and positively charged/aromatic cluster from the activation segment (AS). We show that residues from these regions form an extended membrane-interacting surface that resembles the membrane-interacting residues from known membrane-binding domains. Activating phosphorylatable regions (NtA and AS), make direct contact with the membrane whereas R.RKTR forms specific multivalent salt bridges with PA. PA lipids dwell for longer times around the R.RKTR motif. Our results suggest that membrane interaction of monomeric cRaf kinase domain likely orchestrates the Raf activation process and modulates its function. We show that R.RKTR is a hotspot that interacts with membrane when cRaf is monomeric and becomes part of the interface upon Raf dimerization. We propose that in terms of utilizing a specific hotspot to form membrane interaction and dimer formation, both Raf and its upstream binding partner KRas, are similar.
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50
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Prakash P, Litwin D, Liang H, Sarkar-Banerjee S, Dolino D, Zhou Y, Hancock JF, Jayaraman V, Gorfe AA. Dynamics of Membrane-Bound G12V-KRAS from Simulations and Single-Molecule FRET in Native Nanodiscs. Biophys J 2019; 116:179-183. [PMID: 30616834 PMCID: PMC6350008 DOI: 10.1016/j.bpj.2018.12.011] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 12/06/2018] [Accepted: 12/14/2018] [Indexed: 12/30/2022] Open
Abstract
Recent studies have shown that the small GTPase KRAS adopts multiple orientations with respect to the plane of anionic model membranes, whereby either the three C-terminal helices or the three N-terminal β-strands of the catalytic domain face the membrane. This has functional implications because, in the latter, the membrane occludes the effector-interacting surface. However, it remained unclear how membrane reorientation occurs and, critically, whether it occurs in the cell in which KRAS operates as a molecular switch in signaling pathways. Herein, using data from a 20 μs-long atomistic molecular dynamics simulation of the oncogenic G12V-KRAS mutant in a phosphatidylcholine/phosphatidylserine bilayer, we first show that internal conformational fluctuations of flexible regions in KRAS result in three distinct membrane orientations. We then show, using single-molecule fluorescence resonance energy transfer measurements in native lipid nanodiscs derived from baby hamster kidney cells, that G12V-KRAS samples three conformational states that correspond to the predicted orientations. The combined results suggest that relatively small energy barriers separate orientation states and that signaling-competent conformations dominate the overall population.
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Affiliation(s)
- Priyanka Prakash
- Department of Integrative Biology and Pharmacology, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, Texas
| | - Douglas Litwin
- Department of Biochemistry and Molecular Biology, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, Texas; Biochemistry and Cell Biology Program, MD Anderson University of Texas Health Science Center at Houston, Graduate School of Biochemical Sciences, Houston, Texas
| | - Hong Liang
- Department of Integrative Biology and Pharmacology, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, Texas
| | - Suparna Sarkar-Banerjee
- Department of Integrative Biology and Pharmacology, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, Texas
| | - Drew Dolino
- Department of Biochemistry and Molecular Biology, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, Texas
| | - Yong Zhou
- Department of Integrative Biology and Pharmacology, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, Texas; Biochemistry and Cell Biology Program, MD Anderson University of Texas Health Science Center at Houston, Graduate School of Biochemical Sciences, Houston, Texas
| | - John F Hancock
- Department of Integrative Biology and Pharmacology, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, Texas; Biochemistry and Cell Biology Program, MD Anderson University of Texas Health Science Center at Houston, Graduate School of Biochemical Sciences, Houston, Texas
| | - Vasanthi Jayaraman
- Department of Biochemistry and Molecular Biology, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, Texas; Biochemistry and Cell Biology Program, MD Anderson University of Texas Health Science Center at Houston, Graduate School of Biochemical Sciences, Houston, Texas
| | - Alemayehu A Gorfe
- Department of Integrative Biology and Pharmacology, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, Texas; Biochemistry and Cell Biology Program, MD Anderson University of Texas Health Science Center at Houston, Graduate School of Biochemical Sciences, Houston, Texas.
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