1
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Singh S, Bernal Astrain G, Hincapie AM, Goudreault M, Smith MJ. Complex interplay between RAS GTPases and RASSF effectors regulates subcellular localization of YAP. EMBO Rep 2024; 25:3574-3600. [PMID: 39009833 PMCID: PMC11316025 DOI: 10.1038/s44319-024-00203-9] [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: 12/06/2023] [Revised: 06/20/2024] [Accepted: 06/25/2024] [Indexed: 07/17/2024] Open
Abstract
RAS GTPases bind effectors to convert upstream cues to changes in cellular function. Effectors of classical H/K/NRAS are defined by RBD/RA domains which recognize the GTP-bound conformation of these GTPases, yet the specificity of RBD/RAs for over 160 RAS superfamily proteins remains poorly explored. We have systematically mapped interactions between BRAF and four RASSF effectors, the largest family of RA-containing proteins, with all RAS, RHO and ARF small GTPases. 39 validated complexes reveal plasticity in RASSF binding, while BRAF demonstrates tight specificity for classical H/K/NRAS. Complex between RASSF5 and diverse RAS GTPases at the plasma membrane can activate Hippo signalling and sequester YAP in the cytosol. RASSF8 undergoes liquid-liquid phase separation and resides in YAP-associated membraneless condensates, which also engage several RAS and RHO GTPases. The poorly studied RASSF3 has been identified as a first potential effector of mitochondrial MIRO proteins, and its co-expression with these GTPases impacts mitochondria and peroxisome distribution. These data reveal the complex nature of GTPase-effector interactions and show their systematic elucidation can reveal completely novel and biologically relevant cellular processes.
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Affiliation(s)
- Swati Singh
- Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, QC, H3T 1J4, Canada
| | - Gabriela Bernal Astrain
- Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, QC, H3T 1J4, Canada
| | - Ana Maria Hincapie
- Rosalind and Morris Goodman Cancer Institute, McGill University, Montréal, QC, H3A 1A3, Canada
| | - Marilyn Goudreault
- Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, QC, H3T 1J4, Canada
| | - Matthew J Smith
- Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, QC, H3T 1J4, Canada.
- Department of Pathology and Cell Biology, Faculty of Medicine, Université de Montréal, Montréal, QC, H3T 1J4, Canada.
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2
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Spencer-Smith R, Morrison DK. Regulation of RAF family kinases: new insights from recent structural and biochemical studies. Biochem Soc Trans 2024; 52:1061-1069. [PMID: 38695730 DOI: 10.1042/bst20230552] [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: 02/24/2024] [Revised: 04/18/2024] [Accepted: 04/22/2024] [Indexed: 06/27/2024]
Abstract
The RAF kinases are required for signal transduction through the RAS-RAF-MEK-ERK pathway, and their activity is frequently up-regulated in human cancer and the RASopathy developmental syndromes. Due to their complex activation process, developing drugs that effectively target RAF function has been a challenging endeavor, highlighting the need for a more detailed understanding of RAF regulation. This review will focus on recent structural and biochemical studies that have provided 'snapshots' into the RAF regulatory cycle, revealing structures of the autoinhibited BRAF monomer, active BRAF and CRAF homodimers, as well as HSP90/CDC37 chaperone complexes containing CRAF or BRAFV600E. In addition, we will describe the insights obtained regarding how BRAF transitions between its regulatory states and examine the roles that various BRAF domains and 14-3-3 dimers play in both maintaining BRAF as an autoinhibited monomer and in facilitating its transition to an active dimer. We will also address the function of the HSP90/CDC37 chaperone complex in stabilizing the protein levels of CRAF and certain oncogenic BRAF mutants, and in serving as a platform for RAF dephosphorylation mediated by the PP5 protein phosphatase. Finally, we will discuss the regulatory differences observed between BRAF and CRAF and how these differences impact the function of BRAF and CRAF as drivers of human disease.
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Affiliation(s)
- Russell Spencer-Smith
- Laboratory of Cell and Developmental Signaling, Center for Cancer Research, National Cancer Institute-Frederick, Frederick, MD 21702, U.S.A
| | - Deborah K Morrison
- Laboratory of Cell and Developmental Signaling, Center for Cancer Research, National Cancer Institute-Frederick, Frederick, MD 21702, U.S.A
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3
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Bonsor DA, Simanshu DK. RAS and SHOC2 Roles in RAF Activation and Therapeutic Considerations. ANNUAL REVIEW OF CANCER BIOLOGY 2024; 8:97-113. [PMID: 38882927 PMCID: PMC11178279 DOI: 10.1146/annurev-cancerbio-062822-030450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2024]
Abstract
Mutations in RAS proteins play a pivotal role in the development of human cancers, driving persistent RAF activation and deregulating the Mitogen-Activated Protein Kinase (MAPK) signaling pathway. While progress has been made in targeting specific oncogenic RAS proteins, effective drug-based therapies for the majority of RAS mutations remain limited. Recent investigations on RAS-RAF complexes and the SHOC2-MRAS-PP1C holoenzyme complex have provided crucial insights into the structural and functional aspects of RAF activation within the MAPK signaling pathway. Moreover, these studies have also unveiled new blueprints for developing inhibitors allowing us to think beyond the current RAS and MEK inhibitors. In this review, we explore the roles of RAS and SHOC2 in activating RAF and discuss potential therapeutic strategies to target these proteins. A comprehensive understanding of the molecular interactions involved in RAF activation and their therapeutic implications holds the potential to drive innovative approaches in combating RAS/RAF-driven cancers.
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Affiliation(s)
- Daniel A. Bonsor
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Dhirendra K. Simanshu
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
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4
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Liu NF, Enomoto M, Marshall CB, Ikura M. Reconstitution and characterization of BRAF in complex with 14-3-3 and KRAS4B on nanodiscs. Protein Sci 2024; 33:e5016. [PMID: 38747381 PMCID: PMC11094772 DOI: 10.1002/pro.5016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Revised: 04/17/2024] [Accepted: 04/25/2024] [Indexed: 05/19/2024]
Abstract
RAF kinases are key components of the RAS-MAPK signaling pathway, which drives cell growth and is frequently overactivated in cancer. Upstream signaling activates the small GTPase RAS, which recruits RAF to the cell membrane, driving a transition of the latter from an auto-inhibited monomeric conformation to an active dimer. Despite recent progress, mechanistic details underlying RAF activation remain unclear, particularly the role of RAS and the membrane in mediating this conformational rearrangement of RAF together with 14-3-3 to permit RAF kinase domain dimerization. Here, we reconstituted an active complex of dimeric BRAF, a 14-3-3 dimer and two KRAS4B on a nanodisc bilayer and verified that its assembly is GTP-dependent. Biolayer interferometry (BLI) was used to compare the binding affinities of monomeric versus dimeric full-length BRAF:14-3-3 complexes for KRAS4B-conjugated nanodiscs (RAS-ND) and to investigate the effects of membrane lipid composition and spatial density of KRAS4B on binding. 1,2-Dioleoyl-sn-glycero-3-phospho-L-serine (DOPS) and higher KRAS4B density enhanced the interaction of BRAF:14-3-3 with RAS-ND to different degrees depending on BRAF oligomeric state. We utilized our reconstituted system to dissect the effects of KRAS4B and the membrane on the kinase activity of monomeric and dimeric BRAF:14-3-3 complexes, finding that KRAS4B or nanodiscs alone were insufficient to stimulate activity, whereas RAS-ND increased activity of both states of BRAF. The reconstituted assembly of full-length BRAF with 14-3-3 and KRAS on a cell-free, defined lipid bilayer offers a more holistic biophysical perspective to probe regulation of this multimeric signaling complex at the membrane surface.
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Affiliation(s)
- Ningdi F. Liu
- Princess Margaret Cancer CentreUniversity Health NetworkTorontoOntarioCanada
- Department of Medical BiophysicsUniversity of TorontoTorontoOntarioCanada
| | - Masahiro Enomoto
- Princess Margaret Cancer CentreUniversity Health NetworkTorontoOntarioCanada
| | | | - Mitsuhiko Ikura
- Princess Margaret Cancer CentreUniversity Health NetworkTorontoOntarioCanada
- Department of Medical BiophysicsUniversity of TorontoTorontoOntarioCanada
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5
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Sanchez C, Ramirez A, Hodgson L. Unravelling molecular dynamics in living cells: Fluorescent protein biosensors for cell biology. J Microsc 2024. [PMID: 38357769 PMCID: PMC11324865 DOI: 10.1111/jmi.13270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Revised: 01/11/2024] [Accepted: 01/22/2024] [Indexed: 02/16/2024]
Abstract
Genetically encoded, fluorescent protein (FP)-based Förster resonance energy transfer (FRET) biosensors are microscopy imaging tools tailored for the precise monitoring and detection of molecular dynamics within subcellular microenvironments. They are characterised by their ability to provide an outstanding combination of spatial and temporal resolutions in live-cell microscopy. In this review, we begin by tracing back on the historical development of genetically encoded FP labelling for detection in live cells, which lead us to the development of early biosensors and finally to the engineering of single-chain FRET-based biosensors that have become the state-of-the-art today. Ultimately, this review delves into the fundamental principles of FRET and the design strategies underpinning FRET-based biosensors, discusses their diverse applications and addresses the distinct challenges associated with their implementation. We place particular emphasis on single-chain FRET biosensors for the Rho family of guanosine triphosphate hydrolases (GTPases), pointing to their historical role in driving our understanding of the molecular dynamics of this important class of signalling proteins and revealing the intricate relationships and regulatory mechanisms that comprise Rho GTPase biology in living cells.
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Affiliation(s)
- Colline Sanchez
- Gruss-Lipper Biophotonics Center, Albert Einstein College of Medicine, Bronx, New York, USA
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Andrea Ramirez
- Gruss-Lipper Biophotonics Center, Albert Einstein College of Medicine, Bronx, New York, USA
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Louis Hodgson
- Gruss-Lipper Biophotonics Center, Albert Einstein College of Medicine, Bronx, New York, USA
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, New York, USA
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6
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Bahar ME, Kim HJ, Kim DR. Targeting the RAS/RAF/MAPK pathway for cancer therapy: from mechanism to clinical studies. Signal Transduct Target Ther 2023; 8:455. [PMID: 38105263 PMCID: PMC10725898 DOI: 10.1038/s41392-023-01705-z] [Citation(s) in RCA: 20] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Revised: 11/03/2023] [Accepted: 11/12/2023] [Indexed: 12/19/2023] Open
Abstract
Metastatic dissemination of solid tumors, a leading cause of cancer-related mortality, underscores the urgent need for enhanced insights into the molecular and cellular mechanisms underlying metastasis, chemoresistance, and the mechanistic backgrounds of individuals whose cancers are prone to migration. The most prevalent signaling cascade governed by multi-kinase inhibitors is the mitogen-activated protein kinase (MAPK) pathway, encompassing the RAS-RAF-MAPK kinase (MEK)-extracellular signal-related kinase (ERK) pathway. RAF kinase is a primary mediator of the MAPK pathway, responsible for the sequential activation of downstream targets, such as MEK and the transcription factor ERK, which control numerous cellular and physiological processes, including organism development, cell cycle control, cell proliferation and differentiation, cell survival, and death. Defects in this signaling cascade are associated with diseases such as cancer. RAF inhibitors (RAFi) combined with MEK blockers represent an FDA-approved therapeutic strategy for numerous RAF-mutant cancers, including melanoma, non-small cell lung carcinoma, and thyroid cancer. However, the development of therapy resistance by cancer cells remains an important barrier. Autophagy, an intracellular lysosome-dependent catabolic recycling process, plays a critical role in the development of RAFi resistance in cancer. Thus, targeting RAF and autophagy could be novel treatment strategies for RAF-mutant cancers. In this review, we delve deeper into the mechanistic insights surrounding RAF kinase signaling in tumorigenesis and RAFi-resistance. Furthermore, we explore and discuss the ongoing development of next-generation RAF inhibitors with enhanced therapeutic profiles. Additionally, this review sheds light on the functional interplay between RAF-targeted therapies and autophagy in cancer.
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Affiliation(s)
- Md Entaz Bahar
- Department of Biochemistry and Convergence Medical Sciences and Institute of Medical Science, Gyeongsang National University, College of Medicine, Jinju, South Korea
| | - Hyun Joon Kim
- Department of Anatomy and Convergence Medical Sciences and Institute of Medical Science, Gyeongsang National University, College of Medicine, Jinju, South Korea
| | - Deok Ryong Kim
- Department of Biochemistry and Convergence Medical Sciences and Institute of Medical Science, Gyeongsang National University, College of Medicine, Jinju, South Korea.
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7
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Imoto H, Rauch N, Neve AJ, Khorsand F, Kreileder M, Alexopoulos LG, Rauch J, Okada M, Kholodenko BN, Rukhlenko OS. A Combination of Conformation-Specific RAF Inhibitors Overcome Drug Resistance Brought about by RAF Overexpression. Biomolecules 2023; 13:1212. [PMID: 37627277 PMCID: PMC10452107 DOI: 10.3390/biom13081212] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Revised: 07/26/2023] [Accepted: 07/31/2023] [Indexed: 08/27/2023] Open
Abstract
Cancer cells often adapt to targeted therapies, yet the molecular mechanisms underlying adaptive resistance remain only partially understood. Here, we explore a mechanism of RAS/RAF/MEK/ERK (MAPK) pathway reactivation through the upregulation of RAF isoform (RAFs) abundance. Using computational modeling and in vitro experiments, we show that the upregulation of RAFs changes the concentration range of paradoxical pathway activation upon treatment with conformation-specific RAF inhibitors. Additionally, our data indicate that the signaling output upon loss or downregulation of one RAF isoform can be compensated by overexpression of other RAF isoforms. We furthermore demonstrate that, while single RAF inhibitors cannot efficiently inhibit ERK reactivation caused by RAF overexpression, a combination of two structurally distinct RAF inhibitors synergizes to robustly suppress pathway reactivation.
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Affiliation(s)
- Hiroaki Imoto
- Systems Biology Ireland, School of Medicine, University College Dublin, D04 V1W8 Dublin, Ireland
| | - Nora Rauch
- Systems Biology Ireland, School of Medicine, University College Dublin, D04 V1W8 Dublin, Ireland
| | - Ashish J. Neve
- Systems Biology Ireland, School of Medicine, University College Dublin, D04 V1W8 Dublin, Ireland
| | - Fahimeh Khorsand
- Systems Biology Ireland, School of Medicine, University College Dublin, D04 V1W8 Dublin, Ireland
| | - Martina Kreileder
- Systems Biology Ireland, School of Medicine, University College Dublin, D04 V1W8 Dublin, Ireland
| | - Leonidas G. Alexopoulos
- Protavio Ltd., Demokritos Science Park, 153 43 Athens, Greece
- Department of Mechanical Engineering, National Technical University of Athens, 106 82 Athens, Greece
| | - Jens Rauch
- Systems Biology Ireland, School of Medicine, University College Dublin, D04 V1W8 Dublin, Ireland
- School of Biomolecular and Biomedical Science, University College Dublin, D04 V1W8 Dublin, Ireland
| | - Mariko Okada
- Institute for Protein Research, Osaka University, Osaka 565-0871, Japan
- Premium Research Institute for Human Metaverse Medicine (WPI-PRIMe), Osaka University, Osaka 565-0871, Japan
| | - Boris N. Kholodenko
- Systems Biology Ireland, School of Medicine, University College Dublin, D04 V1W8 Dublin, Ireland
- Conway Institute of Biomolecular and Biomedical Research, University College Dublin, D04 V1W8 Dublin, Ireland
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Oleksii S. Rukhlenko
- Systems Biology Ireland, School of Medicine, University College Dublin, D04 V1W8 Dublin, Ireland
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8
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Goebel L, Kirschner T, Koska S, Rai A, Janning P, Maffini S, Vatheuer H, Czodrowski P, Goody RS, Müller MP, Rauh D. Targeting oncogenic KRasG13C with nucleotide-based covalent inhibitors. eLife 2023; 12:82184. [PMID: 36972177 PMCID: PMC10042540 DOI: 10.7554/elife.82184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Accepted: 03/03/2023] [Indexed: 03/29/2023] Open
Abstract
Mutations within Ras proteins represent major drivers in human cancer. In this study, we report the structure-based design, synthesis, as well as biochemical and cellular evaluation of nucleotide-based covalent inhibitors for KRasG13C, an important oncogenic mutant of Ras that has not been successfully addressed in the past. Mass spectrometry experiments and kinetic studies reveal promising molecular properties of these covalent inhibitors, and X-ray crystallographic analysis has yielded the first reported crystal structures of KRasG13C covalently locked with these GDP analogues. Importantly, KRasG13C covalently modified with these inhibitors can no longer undergo SOS-catalysed nucleotide exchange. As a final proof-of-concept, we show that in contrast to KRasG13C, the covalently locked protein is unable to induce oncogenic signalling in cells, further highlighting the possibility of using nucleotide-based inhibitors with covalent warheads in KRasG13C-driven cancer.
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Affiliation(s)
- Lisa Goebel
- Department of Chemistry and Chemical Biology, TU Dortmund University, Dortmund, Germany
| | - Tonia Kirschner
- Department of Chemistry and Chemical Biology, TU Dortmund University, Dortmund, Germany
| | - Sandra Koska
- Department of Chemistry and Chemical Biology, TU Dortmund University, Dortmund, Germany
| | - Amrita Rai
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Petra Janning
- Department of Chemical Biology, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Stefano Maffini
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Helge Vatheuer
- Department of Chemistry and Chemical Biology, TU Dortmund University, Dortmund, Germany
| | - Paul Czodrowski
- Department of Chemistry and Chemical Biology, TU Dortmund University, Dortmund, Germany
| | - Roger S Goody
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Matthias P Müller
- Department of Chemistry and Chemical Biology, TU Dortmund University, Dortmund, Germany
| | - Daniel Rauh
- Department of Chemistry and Chemical Biology, TU Dortmund University, Dortmund, Germany
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9
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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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10
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The current state of the art and future trends in RAS-targeted cancer therapies. Nat Rev Clin Oncol 2022; 19:637-655. [PMID: 36028717 PMCID: PMC9412785 DOI: 10.1038/s41571-022-00671-9] [Citation(s) in RCA: 147] [Impact Index Per Article: 73.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/20/2022] [Indexed: 12/18/2022]
Abstract
Despite being the most frequently altered oncogenic protein in solid tumours, KRAS has historically been considered ‘undruggable’ owing to a lack of pharmacologically targetable pockets within the mutant isoforms. However, improvements in drug design have culminated in the development of inhibitors that are selective for mutant KRAS in its active or inactive state. Some of these inhibitors have proven efficacy in patients with KRASG12C-mutant cancers and have become practice changing. The excitement associated with these advances has been tempered by drug resistance, which limits the depth and/or duration of responses to these agents. Improvements in our understanding of RAS signalling in cancer cells and in the tumour microenvironment suggest the potential for several novel combination therapies, which are now being explored in clinical trials. Herein, we provide an overview of the RAS pathway and review the development and current status of therapeutic strategies for targeting oncogenic RAS, as well as their potential to improve outcomes in patients with RAS-mutant malignancies. We then discuss challenges presented by resistance mechanisms and strategies by which they could potentially be overcome. The RAS oncogenes are among the most common drivers of tumour development and progression but have historically been considered undruggable. The development of direct KRAS inhibitors has changed this paradigm, although currently clinical use of these novel therapeutics is limited to a select subset of patients, and intrinsic or acquired resistance presents an inevitable challenge to cure. Herein, the authors provide an overview of the RAS pathway in cancer and review the ongoing efforts to develop effective therapeutic strategies for RAS-mutant cancers. They also discuss the current understanding of mechanisms of resistance to direct KRAS inhibitors and strategies by which they might be overcome. Owing to intrinsic and extrinsic factors, KRAS and other RAS isoforms have until recently been impervious to targeting with small-molecule inhibitors. Inhibitors of the KRASG12C variant constitute a potential breakthrough in the treatment of many cancer types, particularly non-small-cell lung cancer, for which such an agent has been approved by the FDA. Several forms of resistance to KRAS inhibitors have been defined, including primary, adaptive and acquired resistance; these resistance mechanisms are being targeted in studies that combine KRAS inhibitors with inhibitors of horizontal or vertical signalling pathways. Mutant KRAS has important effects on the tumour microenvironment, including the immunological milieu; these effects must be considered to fully understand resistance to KRAS inhibitors and when designing novel treatment strategies.
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11
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Huynh MV, Parsonage D, Forshaw TE, Chirasani VR, Hobbs GA, Wu H, Lee J, Furdui CM, Poole LB, Campbell SL. Oncogenic KRAS G12C: Kinetic and redox characterization of covalent inhibition. J Biol Chem 2022; 298:102186. [PMID: 35753348 PMCID: PMC9352912 DOI: 10.1016/j.jbc.2022.102186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2022] [Revised: 06/14/2022] [Accepted: 06/16/2022] [Indexed: 12/02/2022] Open
Abstract
The recent development of mutant-selective inhibitors for the oncogenic KRASG12C allele has generated considerable excitement. These inhibitors covalently engage the mutant C12 thiol located within the phosphoryl binding loop of RAS, locking the KRASG12C protein in an inactive state. While clinical trials of these inhibitors have been promising, mechanistic questions regarding the reactivity of this thiol remain. Here, we show by NMR and an independent biochemical assay that the pKa of the C12 thiol is depressed (pKa ∼7.6), consistent with susceptibility to chemical ligation. Using a validated fluorescent KRASY137W variant amenable to stopped-flow spectroscopy, we characterized the kinetics of KRASG12C fluorescence changes upon addition of ARS-853 or AMG 510, noting that at low temperatures, ARS-853 addition elicited both a rapid first phase of fluorescence change (attributed to binding, Kd = 36.0 ± 0.7 μM) and a second, slower pH-dependent phase, taken to represent covalent ligation. Consistent with the lower pKa of the C12 thiol, we found that reversible and irreversible oxidation of KRASG12C occurred readily both in vitro and in the cellular environment, preventing the covalent binding of ARS-853. Moreover, we found that oxidation of the KRASG12C Cys12 to a sulfinate altered RAS conformation and dynamics to be more similar to KRASG12D in comparison to the unmodified protein, as assessed by molecular dynamics simulations. Taken together, these findings provide insight for future KRASG12C drug discovery efforts, and identify the occurrence of G12C oxidation with currently unknown biological ramifications.
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Affiliation(s)
- Minh V Huynh
- Department of Biochemistry & Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Derek Parsonage
- Department of Biochemistry, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
| | - Tom E Forshaw
- Department of Internal Medicine, Section on Molecular Medicine, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
| | - Venkat R Chirasani
- Department of Biochemistry & Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - G Aaron Hobbs
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA; Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Hanzhi Wu
- Department of Internal Medicine, Section on Molecular Medicine, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
| | - Jingyun Lee
- Wake Forest Baptist Comprehensive Cancer Center, Winston-Salem, North Carolina, USA
| | - Cristina M Furdui
- Department of Internal Medicine, Section on Molecular Medicine, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA; Wake Forest Baptist Comprehensive Cancer Center, Winston-Salem, North Carolina, USA; Center for Redox Biology and Medicine, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
| | - Leslie B Poole
- Department of Biochemistry, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA; Wake Forest Baptist Comprehensive Cancer Center, Winston-Salem, North Carolina, USA; Center for Redox Biology and Medicine, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA.
| | - Sharon L Campbell
- Department of Biochemistry & Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA; Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.
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12
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Chow A, Khan ZM, Marsiglia WM, Dar AC. Conformational control and regulation of the pseudokinase KSR via small molecule binding interactions. Methods Enzymol 2022; 667:365-402. [PMID: 35525547 PMCID: PMC9150438 DOI: 10.1016/bs.mie.2022.03.039] [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] [Indexed: 11/29/2022]
Abstract
Pseudokinases often operate through functionally related enzymes and receptors. A prime example is the pseudokinase KSR (Kinase Suppressor of RAS), which can act as both an amplifier and inhibitor of members in the RAS-MAPK (Mitogen Activated Protein Kinase) signaling pathway. KSR is structurally related to the active RAF kinases over multiple domains; moreover, the pseudokinase domain of KSR forms physical and regulatory complexes with both RAF and MEK through distinct interfaces. Characterization of small molecule interactions on KSR has been used to uncover novel chemical tools and understand the mechanism of action of clinical drugs. Here, we elaborate on assays and structural methods for measuring binding at orthosteric and interfacial binding sites on KSR. These distinct small molecule pockets provide therapeutic paths for targeting KSR1 and KSR2 pseudokinases in disease, including in RAS and RAF mutant cancers.
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Affiliation(s)
- Arthur Chow
- Department of Oncological Sciences, Department of Pharmacological Sciences, The Tisch Cancer Institute, Mount Sinai Centre for Therapeutic Discovery, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Zaigham M Khan
- Department of Oncological Sciences, Department of Pharmacological Sciences, The Tisch Cancer Institute, Mount Sinai Centre for Therapeutic Discovery, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - William M Marsiglia
- Department of Oncological Sciences, Department of Pharmacological Sciences, The Tisch Cancer Institute, Mount Sinai Centre for Therapeutic Discovery, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Arvin C Dar
- Department of Oncological Sciences, Department of Pharmacological Sciences, The Tisch Cancer Institute, Mount Sinai Centre for Therapeutic Discovery, Icahn School of Medicine at Mount Sinai, New York, NY, United States.
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13
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Burge RA, Hobbs GA. Not all RAS mutations are equal: A detailed review of the functional diversity of RAS hot spot mutations. Adv Cancer Res 2022; 153:29-61. [PMID: 35101234 DOI: 10.1016/bs.acr.2021.07.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The RAS family of small GTPases are among the most frequently mutated oncogenes in human cancer. Approximately 20% of cancers harbor a RAS mutation, and >150 different missense mutations have been detected. Many of these mutations have mutant-specific biochemical defects that alter nucleotide binding and hydrolysis, effector interactions and cell signaling, prompting renewed efforts in the development of anti-RAS therapies, including the mutation-specific strategies. Previously viewed as undruggable, the recent FDA approval of a KRASG12C-selective inhibitor has offered real promise to the development of allele-specific RAS therapies. A broader understanding of the mutational consequences on RAS function must be developed to exploit additional allele-specific vulnerabilities. Approximately 94% of RAS mutations occur at one of three mutational "hot spots" at Gly12, Gly13 and Gln61. Further, the single-nucleotide substitutions represent >99% of these mutations. Within this scope, we discuss the mutational frequencies of RAS isoforms in cancer, mutant-specific effector interactions and biochemical properties. By limiting our analysis to this mutational subset, we simplify the analysis while only excluding a small percentage of total mutations. Combined, these data suggest that the presence or absence of select RAS mutations in human cancers can be linked to their biochemical properties. Continuing to examine the biochemical differences in each RAS-mutant protein will continue to provide additional breakthroughs in allele-specific therapeutic strategies.
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Affiliation(s)
- Rachel A Burge
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Medical University of South Carolina, Charleston, SC, United States
| | - G Aaron Hobbs
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Medical University of South Carolina, Charleston, SC, United States; Hollings Cancer Center, Medical University of South Carolina, Charleston, SC, United States.
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14
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Structural insights into the BRAF monomer-to-dimer transition mediated by RAS binding. Nat Commun 2022; 13:486. [PMID: 35078985 PMCID: PMC8789793 DOI: 10.1038/s41467-022-28084-3] [Citation(s) in RCA: 51] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Accepted: 01/07/2022] [Indexed: 12/20/2022] Open
Abstract
RAF kinases are essential effectors of RAS, but how RAS binding initiates the conformational changes needed for autoinhibited RAF monomers to form active dimers has remained unclear. Here, we present cryo-electron microscopy structures of full-length BRAF complexes derived from mammalian cells: autoinhibited, monomeric BRAF:14-3-32:MEK and BRAF:14-3-32 complexes, and an inhibitor-bound, dimeric BRAF2:14-3-32 complex, at 3.7, 4.1, and 3.9 Å resolution, respectively. In both autoinhibited, monomeric structures, the RAS binding domain (RBD) of BRAF is resolved, revealing that the RBD forms an extensive contact interface with the 14-3-3 protomer bound to the BRAF C-terminal site and that key basic residues required for RBD-RAS binding are exposed. Moreover, through structure-guided mutational studies, our findings indicate that RAS-RAF binding is a dynamic process and that RBD residues at the center of the RBD:14-3-3 interface have a dual function, first contributing to RAF autoinhibition and then to the full spectrum of RAS-RBD interactions. RAF kinases are essential for RAS protein signalling but how RAS binding regulates dimerization and activation of RAF has remained unclear. Here, the authors report cryoEM structures that provide mechanistic insights into the RAS-mediated monomer-to-dimer transition of full-length BRAF.
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15
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Engineered variants of the Ras effector protein RASSF5 (NORE1A) promote anticancer activities in lung adenocarcinoma. J Biol Chem 2021; 297:101353. [PMID: 34717958 PMCID: PMC8605244 DOI: 10.1016/j.jbc.2021.101353] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Revised: 10/12/2021] [Accepted: 10/25/2021] [Indexed: 11/24/2022] Open
Abstract
Within the superfamily of small GTPases, Ras appears to be the master regulator of such processes as cell cycle progression, cell division, and apoptosis. Several oncogenic Ras mutations at amino acid positions 12, 13, and 61 have been identified that lose their ability to hydrolyze GTP, giving rise to constitutive signaling and eventually development of cancer. While disruption of the Ras/effector interface is an attractive strategy for drug design to prevent this constitutive activity, inhibition of this interaction using small molecules is impractical due to the absence of a cavity to which such molecules could bind. However, proteins and especially natural Ras effectors that bind to the Ras/effector interface with high affinity could disrupt Ras/effector interactions and abolish procancer pathways initiated by Ras oncogene. Using a combination of computational design and in vitro evolution, we engineered high-affinity Ras-binding proteins starting from a natural Ras effector, RASSF5 (NORE1A), which is encoded by a tumor suppressor gene. Unlike previously reported Ras oncogene inhibitors, the proteins we designed not only inhibit Ras-regulated procancer pathways, but also stimulate anticancer pathways initiated by RASSF5. We show that upon introduction into A549 lung carcinoma cells, the engineered RASSF5 mutants decreased cell viability and mobility to a significantly greater extent than WT RASSF5. In addition, these mutant proteins induce cellular senescence by increasing acetylation and decreasing phosphorylation of p53. In conclusion, engineered RASSF5 variants provide an attractive therapeutic strategy able to oppose cancer development by means of inhibiting of procancer pathways and stimulating anticancer processes.
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Abstract
As a member of small GTPase family, KRAS protein is a key physiological modulator of various cellular activities including proliferation. However, mutations of KRAS present in numerous cancer types, most frequently in pancreatic (> 60%), colorectal (> 40%), and lung cancers, drive oncogenic processes through overactivation of proliferation. The G12C mutation of KRAS protein is especially abundant in the case of these types of malignancies. Despite its key importance in human disease, KRAS was assumed to be non-druggable for a long time since the protein seemingly lacks potential drug-binding pockets except the nucleotide-binding site, which is difficult to be targeted due to the high affinity of KRAS for both GDP and GTP. Recently, a new approach broke the ice and provided evidence that upon covalent targeting of the G12C mutant KRAS, a highly dynamic pocket was revealed. This novel targeting is especially important since it serves with an inherent solution for drug selectivity. Based on these results, various structure-based drug design projects have been launched to develop selective KRAS mutant inhibitors. In addition to the covalent modification strategy mostly applicable for G12C mutation, different innovative solutions have been suggested for the other frequently occurring oncogenic G12 mutants. Here we summarize the latest advances of this field, provide perspectives for novel approaches, and highlight the special properties of KRAS, which might issue some new challenges.
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Affiliation(s)
- Kinga Nyíri
- Department of Applied Biotechnology and Food Sciences, Budapest University of Technology and Economics, Budapest, 1111, Hungary.
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, 1117, Hungary.
| | - Gergely Koppány
- Department of Applied Biotechnology and Food Sciences, Budapest University of Technology and Economics, Budapest, 1111, Hungary
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, 1117, Hungary
| | - Beáta G Vértessy
- Department of Applied Biotechnology and Food Sciences, Budapest University of Technology and Economics, Budapest, 1111, Hungary.
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, 1117, Hungary.
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17
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Osaka N, Hirota Y, Ito D, Ikeda Y, Kamata R, Fujii Y, Chirasani VR, Campbell SL, Takeuchi K, Senda T, Sasaki AT. Divergent Mechanisms Activating RAS and Small GTPases Through Post-translational Modification. Front Mol Biosci 2021; 8:707439. [PMID: 34307463 PMCID: PMC8295990 DOI: 10.3389/fmolb.2021.707439] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Accepted: 06/22/2021] [Indexed: 12/12/2022] Open
Abstract
RAS is a founding member of the RAS superfamily of GTPases. These small 21 kDa proteins function as molecular switches to initialize signaling cascades involved in various cellular processes, including gene expression, cell growth, and differentiation. RAS is activated by GTP loading and deactivated upon GTP hydrolysis to GDP. Guanine nucleotide exchange factors (GEFs) and GTPase-activating proteins (GAPs) accelerate GTP loading and hydrolysis, respectively. These accessory proteins play a fundamental role in regulating activities of RAS superfamily small GTPase via a conserved guanine binding (G)-domain, which consists of five G motifs. The Switch regions lie within or proximal to the G2 and G3 motifs, and undergo dynamic conformational changes between the GDP-bound "OFF" state and GTP-bound "ON" state. They play an important role in the recognition of regulatory factors (GEFs and GAPs) and effectors. The G4 and G5 motifs are the focus of the present work and lie outside Switch regions. These motifs are responsible for the recognition of the guanine moiety in GTP and GDP, and contain residues that undergo post-translational modifications that underlie new mechanisms of RAS regulation. Post-translational modification within the G4 and G5 motifs activates RAS by populating the GTP-bound "ON" state, either through enhancement of intrinsic guanine nucleotide exchange or impairing GAP-mediated down-regulation. Here, we provide a comprehensive review of post-translational modifications in the RAS G4 and G5 motifs, and describe the role of these modifications in RAS activation as well as potential applications for cancer therapy.
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Affiliation(s)
- Natsuki Osaka
- Institute for Advanced Biosciences, Keio University, Tsuruoka, Japan
| | - Yoshihisa Hirota
- Division of Hematology and Oncology, Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, OH, United States
- Department of Bioscience and Engineering, College of Systems Engineering and Science, Shibaura Institute of Technology, Saitama, Japan
| | - Doshun Ito
- Structural Biology Research Center, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), Tsukuba, Japan
- Faculty of Environment and Information Studies, Keio University, Fujisawa, Japan
| | - Yoshiki Ikeda
- Department of Molecular Genetics, Institute of Biomedical Science, Kansai Medical University, Osaka, Japan
| | - Ryo Kamata
- Institute for Advanced Biosciences, Keio University, Tsuruoka, Japan
| | - Yuki Fujii
- Division of Hematology and Oncology, Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, OH, United States
- Graduate School of Science, Osaka City University, Osaka, Japan
| | - Venkat R. Chirasani
- Department of Biochemistry and Biophysics and Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Sharon L. Campbell
- Department of Biochemistry and Biophysics and Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Koh Takeuchi
- Cellular and Molecular Biotechnology Research Institute, National Institute of Advanced Science and Technology, Tokyo, Japan
| | - Toshiya Senda
- Structural Biology Research Center, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), Tsukuba, Japan
- Department of Accelerator Science, School of High Energy Accelerator Science, SOKENDAI (The Graduate University for Advanced Studies), Tsukuba, Japan
- Faculty of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Japan
| | - Atsuo T. Sasaki
- Institute for Advanced Biosciences, Keio University, Tsuruoka, Japan
- Division of Hematology and Oncology, Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, OH, United States
- Department of Cancer Biology, University of Cincinnati College of Medicine, Columbus, OH, United States
- Department of Neurosurgery, Brain Tumor Center at UC Gardner Neuroscience Institute, Cincinnati, OH, United States
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18
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Baker MJ, Rubio I. Active GTPase Pulldown Protocol. METHODS IN MOLECULAR BIOLOGY (CLIFTON, N.J.) 2021; 2262:117-135. [PMID: 33977474 DOI: 10.1007/978-1-0716-1190-6_7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Ras and its related small GTPases are important signalling nodes that regulate a wide variety of cellular functions. The active form of these proteins exists in a transient GTP bound state that mediates downstream signalling events. The dysregulation of these GTPases has been associated with the progression of multiple diseases, most prominently cancer and developmental syndromes known as Rasopathies. Determining the activation state of Ras and its relatives has hence been of paramount importance for the investigation of the biochemical functions of small GTPases in the cellular signal transduction network. This chapter describes the most broadly employed approach for the rapid, label-free qualitative and semi-quantitative determination of the Ras GTPase activation state, which can readily be adapted to the analysis of other related GTPases. The method relies on the affinity-based isolation of the active GTP-bound fraction of Ras in cellular extracts, followed by its visualization via western blotting. Specifically, we describe the production of the recombinant affinity probes or baits that bind to the respective active GTPases and the pulldown method for isolating the active GTPase fraction from adherent or non-adherent cells. This method allows for the reproducible measurement of active Ras or Ras family GTPases in a wide variety of cellular contexts.
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Affiliation(s)
- Martin J Baker
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Ignacio Rubio
- Institute of Molecular Cell Biology, Center for Molecular Biomedicine, University Hospital Jena, Jena, Germany. .,Clinic for Anaesthesiology and Intensive Care, University Hospital Jena, Jena, Germany.
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19
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Sheffels E, Kortum RL. The Role of Wild-Type RAS in Oncogenic RAS Transformation. Genes (Basel) 2021; 12:genes12050662. [PMID: 33924994 PMCID: PMC8146411 DOI: 10.3390/genes12050662] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 04/23/2021] [Accepted: 04/27/2021] [Indexed: 02/06/2023] Open
Abstract
The RAS family of oncogenes (HRAS, NRAS, and KRAS) are among the most frequently mutated protein families in cancers. RAS-mutated tumors were originally thought to proliferate independently of upstream signaling inputs, but we now know that non-mutated wild-type (WT) RAS proteins play an important role in modulating downstream effector signaling and driving therapeutic resistance in RAS-mutated cancers. This modulation is complex as different WT RAS family members have opposing functions. The protein product of the WT RAS allele of the same isoform as mutated RAS is often tumor-suppressive and lost during tumor progression. In contrast, RTK-dependent activation of the WT RAS proteins from the two non-mutated WT RAS family members is tumor-promoting. Further, rebound activation of RTK–WT RAS signaling underlies therapeutic resistance to targeted therapeutics in RAS-mutated cancers. The contributions of WT RAS to proliferation and transformation in RAS-mutated cancer cells places renewed interest in upstream signaling molecules, including the phosphatase/adaptor SHP2 and the RasGEFs SOS1 and SOS2, as potential therapeutic targets in RAS-mutated cancers.
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20
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Cook FA, Cook SJ. Inhibition of RAF dimers: it takes two to tango. Biochem Soc Trans 2021; 49:237-251. [PMID: 33367512 PMCID: PMC7924995 DOI: 10.1042/bst20200485] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 11/17/2020] [Accepted: 11/23/2020] [Indexed: 02/07/2023]
Abstract
The RAS-regulated RAF-MEK1/2-ERK1/2 pathway promotes cell proliferation and survival and RAS and BRAF proteins are commonly mutated in cancer. This has fuelled the development of small molecule kinase inhibitors including ATP-competitive RAF inhibitors. Type I and type I½ ATP-competitive RAF inhibitors are effective in BRAFV600E/K-mutant cancer cells. However, in RAS-mutant cells these compounds instead promote RAS-dependent dimerisation and paradoxical activation of wild-type RAF proteins. RAF dimerisation is mediated by two key regions within each RAF protein; the RKTR motif of the αC-helix and the NtA-region of the dimer partner. Dimer formation requires the adoption of a closed, active kinase conformation which can be induced by RAS-dependent activation of RAF or by the binding of type I and I½ RAF inhibitors. Binding of type I or I½ RAF inhibitors to one dimer partner reduces the binding affinity of the other, thereby leaving a single dimer partner uninhibited and able to activate MEK. To overcome this paradox two classes of drug are currently under development; type II pan-RAF inhibitors that induce RAF dimer formation but bind both dimer partners thus allowing effective inhibition of both wild-type RAF dimer partners and monomeric active class I mutant RAF, and the recently developed "paradox breakers" which interrupt BRAF dimerisation through disruption of the αC-helix. Here we review the regulation of RAF proteins, including RAF dimers, and the progress towards effective targeting of the wild-type RAF proteins.
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Affiliation(s)
- Frazer A. Cook
- Signalling Programme, The Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, U.K
| | - Simon J. Cook
- Signalling Programme, The Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, U.K
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21
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Chang CC, Hsia KC. More than a zip code: global modulation of cellular function by nuclear localization signals. FEBS J 2020; 288:5569-5585. [PMID: 33296547 DOI: 10.1111/febs.15659] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2020] [Revised: 12/03/2020] [Accepted: 12/07/2020] [Indexed: 12/27/2022]
Abstract
Extensive structural and functional studies have been carried out in the field of nucleocytoplasmic transport. Nuclear transport factors, such as Importin-α/-β, recognize nuclear localization signals (NLSs) on cargo, and together with the small GTPase Ran, facilitate their nuclear localization. However, it is now emerging that binding of nuclear transport factors to NLSs not only mediates nuclear transport but also contributes to a variety of cellular functions in eukaryotes. Here, we describe recent advances that reveal how NLSs facilitate diverse cellular functions beyond nuclear transport activity. We review separately NLS-mediated regulatory mechanisms at different levels of biological organization, including (a) assembly of higher-order structures; (b) cellular organelle dynamics; and (c) modulation of cellular stress responses and viral infections. Finally, we provide mechanistic insights into how NLSs can regulate such a broad range of functions via their structural and biochemical properties.
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Affiliation(s)
- Chih-Chia Chang
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Kuo-Chiang Hsia
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan.,Institute of Biochemistry and Molecular Biology, College of Life Sciences, National Yang-Ming University, Taipei, Taiwan
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22
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Gasper R, Wittinghofer F. The Ras switch in structural and historical perspective. Biol Chem 2020; 401:143-163. [PMID: 31600136 DOI: 10.1515/hsz-2019-0330] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Accepted: 09/23/2019] [Indexed: 12/22/2022]
Abstract
Since its discovery as an oncogene more than 40 years ago, Ras has been and still is in the focus of many academic and pharmaceutical labs around the world. A huge amount of work has accumulated on its biology. However, many questions about the role of the different Ras isoforms in health and disease still exist and a full understanding will require more intensive work in the future. Here we try to survey some of the structural findings in a historical perspective and how it has influenced our understanding of structure-function and mechanistic relationships of Ras and its interactions. The structures show that Ras is a stable molecular machine that uses the dynamics of its switch regions for the interaction with all regulators and effectors. This conformational flexibility has been used to create small molecule drug candidates against this important oncoprotein.
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Affiliation(s)
- Raphael Gasper
- Max-Planck-Institut für molekulare Physiologie, Otto-Hahn-Str. 11, D-44227 Dortmund, Germany
| | - Fred Wittinghofer
- Max-Planck-Institut für molekulare Physiologie, Otto-Hahn-Str. 11, D-44227 Dortmund, Germany
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23
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Travers T, López CA, Agamasu C, Hettige JJ, Messing S, García AE, Stephen AG, Gnanakaran S. Anionic Lipids Impact RAS-Binding Site Accessibility and Membrane Binding Affinity of CRAF RBD-CRD. Biophys J 2020; 119:525-538. [PMID: 32649863 PMCID: PMC7399501 DOI: 10.1016/j.bpj.2020.06.021] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 06/12/2020] [Accepted: 06/18/2020] [Indexed: 11/25/2022] Open
Abstract
CRAF activation requires binding to membrane-anchored and active GTP-bound RAS. Whereas its RAS-binding domain (RBD) contains the main binding interface to the RAS G domain, its cysteine-rich domain (CRD) is responsible for association to anionic lipid-rich membranes. Both RAF domains are connected by a short linker, and it remains unclear if the two domains act independently or if one domain can impact the function of the other. Here, we used a combination of coarse-grained and all-atom molecular dynamics simulations of a CRAF RBD-CRD construct to investigate the dynamics of the RBD when it is tethered to CRD that is anchored to a POPC:POPS model membrane. First, we show that the RBD positioning is very dynamic with a preferential localization near the membrane surface. Next, we show that membrane-localized RBD has its RAS-binding interface mostly inaccessible because of its proximity to the membrane. Several positively charged residues in this interface were identified from simulations as important for driving RBD association to the membrane. Surface plasmon resonance (SPR) measurements confirmed that mutations of these RBD residues reduced the liposome partitioning of RBD-CRD. Last, simulations indicated that the presence of RBD near the membrane led to a local enrichment of anionic lipids that could potentially enhance the membrane affinity of the entire RBD-CRD construct. This was supported by SPR measurements that showed stronger liposome partitioning of RBD-CRD relative to CRD alone. These findings thus suggest that the RBD and CRD have synergistic effects on their membrane dynamics, with CRD bringing RBD closer to the membrane that impacts its accessibility to RAS and with RBD causing local anionic lipid enrichment that enhances the overall affinity between the membrane and RBD-CRD. These mechanisms have potential implications on the order of events of the interactions between RAS and CRAF at the membrane.
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Affiliation(s)
- Timothy Travers
- Theoretical Biology and Biophysics Group, Los Alamos, New Mexico; Center for Nonlinear Studies, Los Alamos National Laboratory, Los Alamos, New Mexico
| | - Cesar A López
- Theoretical Biology and Biophysics Group, Los Alamos, New Mexico
| | - Constance Agamasu
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Reseach, Inc., Frederick, Maryland
| | | | - Simon Messing
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Reseach, Inc., Frederick, Maryland
| | - Angel E García
- Center for Nonlinear Studies, Los Alamos National Laboratory, Los Alamos, New Mexico
| | - Andrew G Stephen
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Reseach, Inc., Frederick, Maryland
| | - S Gnanakaran
- Theoretical Biology and Biophysics Group, Los Alamos, New Mexico.
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Lowegard AU, Frenkel MS, Holt GT, Jou JD, Ojewole AA, Donald BR. Novel, provable algorithms for efficient ensemble-based computational protein design and their application to the redesign of the c-Raf-RBD:KRas protein-protein interface. PLoS Comput Biol 2020; 16:e1007447. [PMID: 32511232 PMCID: PMC7329130 DOI: 10.1371/journal.pcbi.1007447] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 07/01/2020] [Accepted: 05/13/2020] [Indexed: 11/25/2022] Open
Abstract
The K* algorithm provably approximates partition functions for a set of states (e.g., protein, ligand, and protein-ligand complex) to a user-specified accuracy ε. Often, reaching an ε-approximation for a particular set of partition functions takes a prohibitive amount of time and space. To alleviate some of this cost, we introduce two new algorithms into the osprey suite for protein design: fries, a Fast Removal of Inadequately Energied Sequences, and EWAK*, an Energy Window Approximation to K*. fries pre-processes the sequence space to limit a design to only the most stable, energetically favorable sequence possibilities. EWAK* then takes this pruned sequence space as input and, using a user-specified energy window, calculates K* scores using the lowest energy conformations. We expect fries/EWAK* to be most useful in cases where there are many unstable sequences in the design sequence space and when users are satisfied with enumerating the low-energy ensemble of conformations. In combination, these algorithms provably retain calculational accuracy while limiting the input sequence space and the conformations included in each partition function calculation to only the most energetically favorable, effectively reducing runtime while still enriching for desirable sequences. This combined approach led to significant speed-ups compared to the previous state-of-the-art multi-sequence algorithm, BBK*, while maintaining its efficiency and accuracy, which we show across 40 different protein systems and a total of 2,826 protein design problems. Additionally, as a proof of concept, we used these new algorithms to redesign the protein-protein interface (PPI) of the c-Raf-RBD:KRas complex. The Ras-binding domain of the protein kinase c-Raf (c-Raf-RBD) is the tightest known binder of KRas, a protein implicated in difficult-to-treat cancers. fries/EWAK* accurately retrospectively predicted the effect of 41 different sets of mutations in the PPI of the c-Raf-RBD:KRas complex. Notably, these mutations include mutations whose effect had previously been incorrectly predicted using other computational methods. Next, we used fries/EWAK* for prospective design and discovered a novel point mutation that improves binding of c-Raf-RBD to KRas in its active, GTP-bound state (KRasGTP). We combined this new mutation with two previously reported mutations (which were highly-ranked by osprey) to create a new variant of c-Raf-RBD, c-Raf-RBD(RKY). fries/EWAK* in osprey computationally predicted that this new variant binds even more tightly than the previous best-binding variant, c-Raf-RBD(RK). We measured the binding affinity of c-Raf-RBD(RKY) using a bio-layer interferometry (BLI) assay, and found that this new variant exhibits single-digit nanomolar affinity for KRasGTP, confirming the computational predictions made with fries/EWAK*. This new variant binds roughly five times more tightly than the previous best known binder and roughly 36 times more tightly than the design starting point (wild-type c-Raf-RBD). This study steps through the advancement and development of computational protein design by presenting theory, new algorithms, accurate retrospective designs, new prospective designs, and biochemical validation. Computational structure-based protein design is an innovative tool for redesigning proteins to introduce a particular or novel function. One such function is improving the binding of one protein to another, which can increase our understanding of important protein systems. Herein we introduce two novel, provable algorithms, fries and EWAK*, for more efficient computational structure-based protein design as well as their application to the redesign of the c-Raf-RBD:KRas protein-protein interface. These new algorithms speed-up computational structure-based protein design while maintaining accurate calculations, allowing for larger, previously infeasible protein designs. Additionally, using fries and EWAK* within the osprey suite, we designed the tightest known binder of KRas, a heavily studied cancer target that interacts with a number of different proteins. This previously undiscovered variant of a KRas-binding domain, c-Raf-RBD, has potential to serve as a tool to further probe the protein-protein interface of KRas with its effectors and its discovery alone emphasizes the potential for more successful applications of computational structure-based protein design.
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Affiliation(s)
- Anna U. Lowegard
- Program in Computational Biology and Bioinformatics, Duke University Medical Center, Durham, North Carolina, United States of America
- Department of Computer Science, Duke University, Durham, North Carolina, United States of America
| | - Marcel S. Frenkel
- Department of Biochemistry, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Graham T. Holt
- Program in Computational Biology and Bioinformatics, Duke University Medical Center, Durham, North Carolina, United States of America
- Department of Computer Science, Duke University, Durham, North Carolina, United States of America
| | - Jonathan D. Jou
- Department of Computer Science, Duke University, Durham, North Carolina, United States of America
| | - Adegoke A. Ojewole
- Program in Computational Biology and Bioinformatics, Duke University Medical Center, Durham, North Carolina, United States of America
- Department of Computer Science, Duke University, Durham, North Carolina, United States of America
| | - Bruce R. Donald
- Department of Computer Science, Duke University, Durham, North Carolina, United States of America
- Department of Biochemistry, Duke University Medical Center, Durham, North Carolina, United States of America
- * E-mail:
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25
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Li L, Möbitz S, Winter R. Characterization of the Spatial Organization of Raf Isoforms Interacting with K-Ras4B in the Lipid Membrane. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:5944-5953. [PMID: 32390436 DOI: 10.1021/acs.langmuir.0c00770] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Activation of Raf kinases by the membrane-anchored protein K-Ras4B is a key step of cellular signal regulation. As a predominant variant of the Ras family, K-Ras4B has been considered to be a major drug target in cancer therapy. Therefore, an integrated study of Raf interaction with membrane-associated K-Ras4B is essential. While the Ras-binding domain (RBD) of Raf contains the main binding interface to K-Ras4B, its cysteine-rich domain (CRD) is thought to be responsible for its association with the membrane interface. We applied time-lapse tapping-mode atomic force microscopy to visualize and characterize the interaction of these binding motifs of A-, B-, and C-Raf isoforms with K-Ras4B in a raft-like anionic model biomembrane. However, we found that the RBDs of the Raf isomers are readily recruited to K-Ras4B nanoclusters in the lipid membrane, with different efficiencies. Unexpectedly and different from A-Raf-RBD, B- and C-Raf-RBD are able to bind markedly also directly to the lipid membrane. We also found that Raf-RBD-CRD is readily recruited to the K-Ras4B forming nanoclusters in the fluid membrane phase, with the CRD domains binding to the lipid interface. The K-Ras4B-nanoclusters are likely to enhance Raf binding and activate signaling by enriching the Raf proteins and facilitating formation of Raf dimers. Interestingly, A-, B-, and C-Raf-RBD-CRD are also able to bind directly to the heterogeneous membrane surrounding the K-Ras4B nanoclusters, which could potentially enhance the overall affinity to K-Ras4B in a Raf-isoform-dependent manner. Overall, these results provide new insights into the spatial organization of the membrane-associated Raf-Ras signaling module for the various Raf isoforms, which is important for understanding the activation of Raf kinases and required for the development of drugs against cancers through targeting Raf-Ras interactions.
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Affiliation(s)
- Lei Li
- Faculty of Chemistry and Chemical Biology, Physical Chemistry I-Biophysical Chemistry, TU Dortmund University, Otto-Hahn-Str. 4a, D-44227 Dortmund, Germany
| | - Simone Möbitz
- Faculty of Chemistry and Chemical Biology, Physical Chemistry I-Biophysical Chemistry, TU Dortmund University, Otto-Hahn-Str. 4a, D-44227 Dortmund, Germany
| | - Roland Winter
- Faculty of Chemistry and Chemical Biology, Physical Chemistry I-Biophysical Chemistry, TU Dortmund University, Otto-Hahn-Str. 4a, D-44227 Dortmund, Germany
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26
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Jang H, Zhang M, Nussinov R. The quaternary assembly of KRas4B with Raf-1 at the membrane. Comput Struct Biotechnol J 2020; 18:737-748. [PMID: 32257057 PMCID: PMC7125320 DOI: 10.1016/j.csbj.2020.03.018] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Revised: 03/17/2020] [Accepted: 03/19/2020] [Indexed: 02/07/2023] Open
Abstract
Proximally located in the membrane, oncogenic Ras dimers (or nanoclusters) can recruit and promote Raf dimerization and MAPK (Raf/MEK/ERK) signaling. Among Ras isoforms, KRas4B is the most frequently mutated. Recent data on the binary KRas4B–Raf-1 complex suggested that Raf-1 CRD not only executes membrane anchorage, but also supports the high-affinity interaction of Raf-1 RBD with KRas4B catalytic domain. For a detailed mechanistic picture of Raf activation at the membrane, we employ explicit MD simulations of the quaternary KRas4B–Raf-1 complex. The complex contains two active GTP-bound KRas4B proteins forming a dimer through the allosteric lobe interface and two tandem RBD-CRD segments of Raf-1 interacting with the effector lobes at both ends of the KRas4B dimer. We show that Raf-1 RBD-CRD supports stable KRas4B dimer at preferred interface and orientation at the membrane, thereby cooperatively enhancing the affinity of the KRas4B–Raf-1 interaction. We propose that a Ras dimer at the membrane can increase the population of proximal Raf kinase domains, promoting kinase domain dimerization in the cytoplasm. Collectively, the dynamic Ras–Raf assembly promotes Raf activation not by allostery; instead, Ras activates Raf by shifting its ensemble toward kinase domain-accessible states through enhanced affinity at the membrane.
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Affiliation(s)
- Hyunbum Jang
- Computational Structural Biology Section, Basic Science Program, Frederick National Laboratory for Cancer Research, Frederick, MD 21702, USA
| | - Mingzhen Zhang
- Computational Structural Biology Section, Basic Science Program, Frederick National Laboratory for Cancer Research, Frederick, MD 21702, USA
| | - Ruth Nussinov
- Computational Structural Biology Section, Basic Science Program, Frederick National Laboratory for Cancer Research, Frederick, MD 21702, USA.,Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
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27
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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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28
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Hobbs GA, Baker NM, Miermont AM, Thurman RD, Pierobon M, Tran TH, Anderson AO, Waters AM, Diehl JN, Papke B, Hodge RG, Klomp JE, Goodwin CM, DeLiberty JM, Wang J, Ng RWS, Gautam P, Bryant KL, Esposito D, Campbell SL, Petricoin EF, Simanshu DK, Aguirre AJ, Wolpin BM, Wennerberg K, Rudloff U, Cox AD, Der CJ. Atypical KRAS G12R Mutant Is Impaired in PI3K Signaling and Macropinocytosis in Pancreatic Cancer. Cancer Discov 2020; 10:104-123. [PMID: 31649109 PMCID: PMC6954322 DOI: 10.1158/2159-8290.cd-19-1006] [Citation(s) in RCA: 120] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 10/17/2019] [Accepted: 10/18/2019] [Indexed: 11/16/2022]
Abstract
Allele-specific signaling by different KRAS alleles remains poorly understood. The KRAS G12R mutation displays uneven prevalence among cancers that harbor the highest occurrence of KRAS mutations: It is rare (∼1%) in lung and colorectal cancers, yet relatively common (∼20%) in pancreatic ductal adenocarcinoma (PDAC), suggesting context-specific properties. We evaluated whether KRASG12R is functionally distinct from the more common KRASG12D- or KRASG12V-mutant proteins (KRASG12D/V). We found that KRASG12D/V but not KRASG12R drives macropinocytosis and that MYC is essential for macropinocytosis in KRASG12D/V- but not KRASG12R-mutant PDAC. Surprisingly, we found that KRASG12R is defective for interaction with a key effector, p110α PI3K (PI3Kα), due to structural perturbations in switch II. Instead, upregulated KRAS-independent PI3Kγ activity was able to support macropinocytosis in KRASG12R-mutant PDAC. Finally, we determined that KRASG12R-mutant PDAC displayed a distinct drug sensitivity profile compared with KRASG12D-mutant PDAC but is still responsive to the combined inhibition of ERK and autophagy. SIGNIFICANCE: We determined that KRASG12R is impaired in activating a key effector, p110α PI3K. As such, KRASG12R is impaired in driving macropinocytosis. However, overexpression of PI3Kγ in PDAC compensates for this deficiency, providing one basis for the prevalence of this otherwise rare KRAS mutant in pancreatic cancer but not other cancers.See related commentary by Falcomatà et al., p. 23.This article is highlighted in the In This Issue feature, p. 1.
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Affiliation(s)
- G Aaron Hobbs
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Nicole M Baker
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | | | - Ryan D Thurman
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Mariaelena Pierobon
- Center for Applied Proteomics and Molecular Medicine, George Mason University, Manassas, Virginia
| | - Timothy H Tran
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc., Frederick, Maryland
| | | | - Andrew M Waters
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - J Nathaniel Diehl
- Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Bjoern Papke
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Richard G Hodge
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Jennifer E Klomp
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Craig M Goodwin
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Jonathan M DeLiberty
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Junning Wang
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts
| | - Raymond W S Ng
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts
| | - Prson Gautam
- Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Helsinki, Finland
| | - Kirsten L Bryant
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Dominic Esposito
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc., Frederick, Maryland
| | - Sharon L Campbell
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Emanuel F Petricoin
- Center for Applied Proteomics and Molecular Medicine, George Mason University, Manassas, Virginia
| | - Dhirendra K Simanshu
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc., Frederick, Maryland
| | - Andrew J Aguirre
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts
| | - Brian M Wolpin
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts
| | - Krister Wennerberg
- Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Helsinki, Finland
- Biotech Research and Innovation Centre (BRIC), University of Copenhagen, Copenhagen, Denmark
| | - Udo Rudloff
- Thoracic and GI Oncology Branch, NCI, Bethesda, Maryland.
- Rare Tumor Initiative, Pediatric Oncology Branch, NCI, Bethesda, Maryland
| | - Adrienne D Cox
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
- Department of Radiation Oncology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Channing J Der
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
- Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
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29
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Mattox TE, Chen X, Maxuitenko YY, Keeton AB, Piazza GA. Exploiting RAS Nucleotide Cycling as a Strategy for Drugging RAS-Driven Cancers. Int J Mol Sci 2019; 21:ijms21010141. [PMID: 31878223 PMCID: PMC6982188 DOI: 10.3390/ijms21010141] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Revised: 12/20/2019] [Accepted: 12/20/2019] [Indexed: 12/12/2022] Open
Abstract
Oncogenic mutations in RAS genes result in the elevation of cellular active RAS protein levels and increased signal propagation through downstream pathways that drive tumor cell proliferation and survival. These gain-of-function mutations drive over 30% of all human cancers, presenting promising therapeutic potential for RAS inhibitors. However, many have deemed RAS “undruggable” after nearly 40 years of failed drug discovery campaigns aimed at identifying a RAS inhibitor with clinical activity. Here we review RAS nucleotide cycling and the opportunities that RAS biochemistry presents for developing novel RAS inhibitory compounds. Additionally, compounds that have been identified to inhibit RAS by exploiting various aspects of RAS biology and biochemistry will be covered. Our current understanding of the biochemical properties of RAS, along with reports of direct-binding inhibitors, both provide insight on viable strategies for the discovery of novel clinical candidates with RAS inhibitory activity.
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Affiliation(s)
- Tyler E. Mattox
- Drug Discovery Research Center, University of South Alabama Mitchell Cancer Institute, Mobile, AL 36604, USA; (X.C.); (Y.Y.M.); (A.B.K.); (G.A.P.)
- Correspondence:
| | - Xi Chen
- Drug Discovery Research Center, University of South Alabama Mitchell Cancer Institute, Mobile, AL 36604, USA; (X.C.); (Y.Y.M.); (A.B.K.); (G.A.P.)
- ADT Pharmaceuticals, Orange Beach, AL 36561, USA
| | - Yulia Y. Maxuitenko
- Drug Discovery Research Center, University of South Alabama Mitchell Cancer Institute, Mobile, AL 36604, USA; (X.C.); (Y.Y.M.); (A.B.K.); (G.A.P.)
| | - Adam B. Keeton
- Drug Discovery Research Center, University of South Alabama Mitchell Cancer Institute, Mobile, AL 36604, USA; (X.C.); (Y.Y.M.); (A.B.K.); (G.A.P.)
- ADT Pharmaceuticals, Orange Beach, AL 36561, USA
| | - Gary A. Piazza
- Drug Discovery Research Center, University of South Alabama Mitchell Cancer Institute, Mobile, AL 36604, USA; (X.C.); (Y.Y.M.); (A.B.K.); (G.A.P.)
- ADT Pharmaceuticals, Orange Beach, AL 36561, USA
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30
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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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31
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Yoshino H, Yin G, Kawaguchi R, Popov KI, Temple B, Sasaki M, Kofuji S, Wolfe K, Kofuji K, Okumura K, Randhawa J, Malhotra A, Majd N, Ikeda Y, Shimada H, Kahoud ER, Haviv S, Iwase S, Asara JM, Campbell SL, Sasaki AT. Identification of lysine methylation in the core GTPase domain by GoMADScan. PLoS One 2019; 14:e0219436. [PMID: 31390367 PMCID: PMC6685615 DOI: 10.1371/journal.pone.0219436] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Accepted: 06/24/2019] [Indexed: 12/19/2022] Open
Abstract
RAS is the founding member of a superfamily of GTPases and regulates signaling pathways involved in cellular growth control. While recent studies have shown that the activation state of RAS can be controlled by lysine ubiquitylation and acetylation, the existence of lysine methylation of the RAS superfamily GTPases remains unexplored. In contrast to acetylation, methylation does not alter the side chain charge and it has been challenging to deduce its impact on protein structure by conventional amino acid substitutions. Herein, we investigate lysine methylation on RAS and RAS-related GTPases. We developed GoMADScan (Go language-based Modification Associated Database Scanner), a new user-friendly application that scans and extracts posttranslationally modified peptides from databases. The GoMADScan search on PhosphoSitePlus databases identified methylation of conserved lysine residues in the core GTPase domain of RAS superfamily GTPases, including residues corresponding to RAS Lys-5, Lys-16, and Lys-117. To follow up on these observations, we immunoprecipitated endogenous RAS from HEK293T cells, conducted mass spectrometric analysis and found that RAS residues, Lys-5 and Lys-147, undergo dimethylation and monomethylation, respectively. Since mutations of Lys-5 have been found in cancers and RASopathies, we set up molecular dynamics (MD) simulations to assess the putative impact of Lys-5 dimethylation on RAS structure. Results from our MD analyses predict that dimethylation of Lys-5 does not significantly alter RAS conformation, suggesting that Lys-5 methylation may alter existing protein interactions or create a docking site to foster new interactions. Taken together, our findings uncover the existence of lysine methylation as a novel posttranslational modification associated with RAS and the RAS superfamily GTPases, and putative impact of Lys-5 dimethylation on RAS structure.
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Affiliation(s)
- Hirofumi Yoshino
- Division of Hematology and Oncology, Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
| | - Guowei Yin
- Department of Biochemistry and Biophysics and Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, Chapel Hill, North Carolina, United States of America
| | - Risa Kawaguchi
- Division of Hematology and Oncology, Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, University of Tokyo, Kashiwa, Chiba, Japan
| | - Konstantin I. Popov
- Department of Biochemistry and Biophysics and Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, Chapel Hill, North Carolina, United States of America
| | - Brenda Temple
- University of North Carolina, R. L. Juliano Structural Bioinformatics Core Facility, Chapel Hill, North Carolina, United States of America
| | - Mika Sasaki
- Division of Hematology and Oncology, Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
| | - Satoshi Kofuji
- Division of Hematology and Oncology, Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
| | - Kara Wolfe
- Division of Hematology and Oncology, Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
| | - Kaori Kofuji
- Division of Hematology and Oncology, Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
| | - Koichi Okumura
- Division of Hematology and Oncology, Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
| | - Jaskirat Randhawa
- Division of Hematology and Oncology, Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
| | - Akshiv Malhotra
- Division of Hematology and Oncology, Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
| | - Nazanin Majd
- Department of Neurology, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
| | - Yoshiki Ikeda
- Division of Hematology and Oncology, Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
| | - Hiroko Shimada
- Division of Hematology and Oncology, Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
| | - Emily Rose Kahoud
- Harvard Medical School, Department of Medicine and Beth Israel Deaconess Medical Center, Division of Signal Transduction, Boston, Massachusetts, United States of America
| | - Sasson Haviv
- Harvard Medical School, Department of Medicine and Beth Israel Deaconess Medical Center, Division of Signal Transduction, Boston, Massachusetts, United States of America
| | - Shigeki Iwase
- Department of Human Genetics, University of Michigan, 5815 Medical Science II, Ann Arbor, Michigan, United States of America
| | - John M. Asara
- Harvard Medical School, Department of Medicine and Beth Israel Deaconess Medical Center, Division of Signal Transduction, Boston, Massachusetts, United States of America
| | - Sharon L. Campbell
- Department of Biochemistry and Biophysics and Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, Chapel Hill, North Carolina, United States of America
| | - Atsuo T. Sasaki
- Division of Hematology and Oncology, Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
- Department of Cancer Biology, University of Cincinnati College of Medicine, Ohio, United States of America
- Department of Neurosurgery, Brain Tumor Center at UC Gardner Neuroscience Institute, Cincinnati, Ohio, United States of America
- Institute for Advanced Biosciences, Keio University, Tsuruoka, Yamagata, Japan
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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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IQGAP-related protein IqgC suppresses Ras signaling during large-scale endocytosis. Proc Natl Acad Sci U S A 2019; 116:1289-1298. [PMID: 30622175 DOI: 10.1073/pnas.1810268116] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Macropinocytosis and phagocytosis are evolutionarily conserved forms of bulk endocytosis used by cells to ingest large volumes of fluid and solid particles, respectively. Both processes are regulated by Ras signaling, which is precisely controlled by mechanisms involving Ras GTPase activating proteins (RasGAPs) responsible for terminating Ras activity on early endosomes. While regulation of Ras signaling during large-scale endocytosis in WT Dictyostelium has been, for the most part, attributed to the Dictyostelium ortholog of human RasGAP NF1, in commonly used axenic laboratory strains, this gene is mutated and inactive. Moreover, none of the RasGAPs characterized so far have been implicated in the regulation of Ras signaling in large-scale endocytosis in axenic strains. In this study, we establish, using biochemical approaches and complementation assays in live cells, that Dictyostelium IQGAP-related protein IqgC interacts with active RasG and exhibits RasGAP activity toward this GTPase. Analyses of iqgC - and IqgC-overexpressing cells further revealed participation of this GAP in the regulation of both types of large-scale endocytosis and in cytokinesis. Moreover, given the localization of IqgC to phagosomes and, most prominently, to macropinosomes, we propose IqgC acting as a RasG-specific GAP in large-scale endocytosis. The data presented here functionally distinguish IqgC from other members of the Dictyostelium IQGAP family and call for repositioning of this genuine RasGAP outside of the IQGAP group.
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Terrell EM, Morrison DK. Ras-Mediated Activation of the Raf Family Kinases. Cold Spring Harb Perspect Med 2019; 9:cshperspect.a033746. [PMID: 29358316 DOI: 10.1101/cshperspect.a033746] [Citation(s) in RCA: 103] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The extracellular signal-regulated kinase (ERK) cascade comprised of the Raf, MEK, and ERK protein kinases constitutes a key effector cascade used by the Ras GTPases to relay signals regulating cell growth, survival, proliferation, and differentiation. Of the ERK cascade components, the regulation of the Raf kinases is by far the most complex, involving changes in subcellular localization, protein and lipid interactions, as well as alterations in the Raf phosphorylation state. The Raf kinases interact directly with active, membrane-localized Ras, and this interaction is often the first step in the Raf activation process, which ultimately results in ERK activation and the downstream phosphorylation of cellular targets that will specify a particular biological response. Here, we will examine our current understanding of how Ras promotes Raf activation, focusing on the molecular mechanisms that contribute to the Raf activation/inactivation cycle.
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Affiliation(s)
- Elizabeth M Terrell
- Laboratory of Cell and Developmental Signaling, NCI-Frederick, Frederick, Maryland 21702
| | - Deborah K Morrison
- Laboratory of Cell and Developmental Signaling, NCI-Frederick, Frederick, Maryland 21702
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Structural snapshots of RAF kinase interactions. Biochem Soc Trans 2018; 46:1393-1406. [PMID: 30381334 DOI: 10.1042/bst20170528] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2018] [Revised: 07/25/2018] [Accepted: 07/30/2018] [Indexed: 02/07/2023]
Abstract
RAF (rapidly accelerated fibrosarcoma) Ser/Thr kinases (ARAF, BRAF, and CRAF) link the RAS (rat sarcoma) protein family with the MAPK (mitogen-activated protein kinase) pathway and control cell growth, differentiation, development, aging, and tumorigenesis. Their activity is specifically modulated by protein-protein interactions, post-translational modifications, and conformational changes in specific spatiotemporal patterns via various upstream regulators, including the kinases, phosphatase, GTPases, and scaffold and modulator proteins. Dephosphorylation of Ser-259 (CRAF numbering) and dissociation of 14-3-3 release the RAF regulatory domains RAS-binding domain and cysteine-rich domain for interaction with RAS-GTP and membrane lipids. This, in turn, results in RAF phosphorylation at Ser-621 and 14-3-3 reassociation, followed by its dimerization and ultimately substrate binding and phosphorylation. This review focuses on structural understanding of how distinct binding partners trigger a cascade of molecular events that induces RAF kinase activation.
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Gao XJ, Chong LS, Kim MS, Elowitz MB. Programmable protein circuits in living cells. Science 2018; 361:1252-1258. [PMID: 30237357 DOI: 10.1126/science.aat5062] [Citation(s) in RCA: 198] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Accepted: 08/14/2018] [Indexed: 12/11/2022]
Abstract
Synthetic protein-level circuits could enable engineering of powerful new cellular behaviors. Rational protein circuit design would be facilitated by a composable protein-protein regulation system in which individual protein components can regulate one another to create a variety of different circuit architectures. In this study, we show that engineered viral proteases can function as composable protein components, which can together implement a broad variety of circuit-level functions in mammalian cells. In this system, termed CHOMP (circuits of hacked orthogonal modular proteases), input proteases dock with and cleave target proteases to inhibit their function. These components can be connected to generate regulatory cascades, binary logic gates, and dynamic analog signal-processing functions. To demonstrate the utility of this system, we rationally designed a circuit that induces cell death in response to upstream activators of the Ras oncogene. Because CHOMP circuits can perform complex functions yet be encoded as single transcripts and delivered without genomic integration, they offer a scalable platform to facilitate protein circuit engineering for biotechnological applications.
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Affiliation(s)
- Xiaojing J Gao
- Howard Hughes Medical Institute, Division of Biology and Biological Engineering, Broad Center, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125, USA
| | - Lucy S Chong
- Howard Hughes Medical Institute, Division of Biology and Biological Engineering, Broad Center, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125, USA
| | - Matthew S Kim
- Howard Hughes Medical Institute, Division of Biology and Biological Engineering, Broad Center, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125, USA
| | - Michael B Elowitz
- Howard Hughes Medical Institute, Division of Biology and Biological Engineering, Broad Center, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125, USA.
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Exploring major signaling cascades in melanomagenesis: a rationale route for targetted skin cancer therapy. Biosci Rep 2018; 38:BSR20180511. [PMID: 30166456 PMCID: PMC6167501 DOI: 10.1042/bsr20180511] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Revised: 08/14/2018] [Accepted: 08/24/2018] [Indexed: 02/06/2023] Open
Abstract
Although most melanoma cases may be treated by surgical intervention upon early diagnosis, a significant portion of patients can still be refractory, presenting low survival rates within 5 years after the discovery of the illness. As a hallmark, melanomas are highly prone to evolve into metastatic sites. Moreover, melanoma tumors are highly resistant to most available drug therapies and their incidence have increased over the years, therefore leading to public health concerns about the development of novel therapies. Therefore, researches are getting deeper in unveiling the mechanisms by which melanoma initiation can be triggered and sustained. In this context, important progress has been achieved regarding the roles and the impact of cellular signaling pathways in melanoma. This knowledge has provided tools for the development of therapies based on the intervention of signal(s) promoted by these cascades. In this review, we summarize the importance of major signaling pathways (mitogen-activated protein kinase (MAPK), phosphoinositide 3-kinase (PI3K)-Akt, Wnt, nuclear factor κ-light-chain-enhancer of activated B cell (NF-κB), Janus kinase (JAK)-signal transducer and activator of transcription (STAT), transforming growth factor β (TGF-β) and Notch) in skin homeostasis and melanoma progression. Available and developing melanoma therapies interfering with these signaling cascades are further discussed.
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38
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Autoinhibition in Ras effectors Raf, PI3Kα, and RASSF5: a comprehensive review underscoring the challenges in pharmacological intervention. Biophys Rev 2018; 10:1263-1282. [PMID: 30269291 PMCID: PMC6233353 DOI: 10.1007/s12551-018-0461-0] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Accepted: 09/17/2018] [Indexed: 02/06/2023] Open
Abstract
Autoinhibition is an effective mechanism that guards proteins against spurious activation. Despite its ubiquity, the distinct organizations of the autoinhibited states and their release mechanisms differ. Signaling is most responsive to the cell environment only if a small shift in the equilibrium is required to switch the system from an inactive (occluded) to an active (exposed) state. Ras signaling follows this paradigm. This underscores the challenge in pharmacological intervention to exploit and enhance autoinhibited states. Here, we review autoinhibition and release mechanisms at the membrane focusing on three representative Ras effectors, Raf protein kinase, PI3Kα lipid kinase, and NORE1A (RASSF5) tumor suppressor, and point to the ramifications to drug discovery. We further touch on Ras upstream and downstream signaling, Ras activation, and the Ras superfamily in this light, altogether providing a broad outlook of the principles and complexities of autoinhibition.
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39
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Sheffels E, Sealover NE, Wang C, Kim DH, Vazirani IA, Lee E, M Terrell E, Morrison DK, Luo J, Kortum RL. Oncogenic RAS isoforms show a hierarchical requirement for the guanine nucleotide exchange factor SOS2 to mediate cell transformation. Sci Signal 2018; 11:11/546/eaar8371. [PMID: 30181243 DOI: 10.1126/scisignal.aar8371] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
About a third of tumors have activating mutations in HRAS, NRAS, or KRAS, genes encoding guanosine triphosphatases (GTPases) of the RAS family. In these tumors, wild-type RAS cooperates with mutant RAS to promote downstream effector activation and cell proliferation and transformation, suggesting that upstream activators of wild-type RAS are important modulators of mutant RAS-driven oncogenesis. The guanine nucleotide exchange factor (GEF) SOS1 mediates KRAS-driven proliferation, but little is understood about the role of SOS2. We found that RAS family members have a hierarchical requirement for the expression and activity of SOS2 to drive cellular transformation. In mouse embryonic fibroblasts (MEFs), SOS2 critically mediated mutant KRAS-driven, but not HRAS-driven, transformation. Sos2 deletion reduced epidermal growth factor (EGF)-dependent activation of wild-type HRAS and phosphorylation of the kinase AKT in cells expressing mutant RAS isoforms. Assays using pharmacological inhibitors revealed a hierarchical requirement for signaling by phosphoinositide 3-kinase (PI3K) in promoting RAS-driven cellular transformation that mirrored the requirement for SOS2. KRAS-driven transformation required the GEF activity of SOS2 and was restored in Sos2-/- MEFs by expression of constitutively activated PI3K. Finally, CRISPR/Cas9-mediated deletion of SOS2 reduced EGF-stimulated AKT phosphorylation and synergized with MEK inhibition to revert the transformed phenotype of human KRAS mutant pancreatic and lung tumor cells. These results indicate that SOS2-dependent PI3K signaling mediates mutant KRAS-driven transformation, revealing therapeutic targets in KRAS-driven cancers. Our data also reveal the importance of three-dimensional culture systems in investigating the mediators of mutant KRAS.
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Affiliation(s)
- Erin Sheffels
- Department of Pharmacology and Molecular Therapeutics, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA
| | - Nancy E Sealover
- Department of Pharmacology and Molecular Therapeutics, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA
| | - Chenyue Wang
- Department of Pharmacology and Molecular Therapeutics, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA
| | - Do Hyung Kim
- Department of Pharmacology and Molecular Therapeutics, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA
| | - Isabella A Vazirani
- Department of Pharmacology and Molecular Therapeutics, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA
| | - Elizabeth Lee
- Department of Pharmacology and Molecular Therapeutics, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA
| | - Elizabeth M Terrell
- Laboratory of Cell and Developmental Signaling, National Cancer Institute (NCI)-Frederick, Frederick, MD 21702, USA
| | - Deborah K Morrison
- Laboratory of Cell and Developmental Signaling, National Cancer Institute (NCI)-Frederick, Frederick, MD 21702, USA
| | - Ji Luo
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, NCI, National Institutes of Health, Bethesda, MD 20892, USA
| | - Robert L Kortum
- Department of Pharmacology and Molecular Therapeutics, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA.
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Travers T, López CA, Van QN, Neale C, Tonelli M, Stephen AG, Gnanakaran S. Molecular recognition of RAS/RAF complex at the membrane: Role of RAF cysteine-rich domain. Sci Rep 2018; 8:8461. [PMID: 29855542 PMCID: PMC5981303 DOI: 10.1038/s41598-018-26832-4] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Accepted: 05/18/2018] [Indexed: 01/14/2023] Open
Abstract
Activation of RAF kinase involves the association of its RAS-binding domain (RBD) and cysteine-rich domain (CRD) with membrane-anchored RAS. However, the overall architecture of the RAS/RBD/CRD ternary complex and the orientations of its constituent domains at the membrane remain unclear. Here, we have combined all-atom and coarse-grained molecular dynamics (MD) simulations with experimental data to construct and validate a model of membrane-anchored CRD, and used this as a basis to explore models of membrane-anchored RAS/RBD/CRD complex. First, simulations of the CRD revealed that it anchors to the membrane via insertion of its two hydrophobic loops, which is consistent with our NMR measurements of CRD bound to nanodiscs. Simulations of the CRD in the context of membrane-anchored RAS/RBD then show how CRD association with either RAS or RBD could play an unexpected role in guiding the membrane orientations of RAS/RBD. This finding has implications for the formation of RAS-RAS dimers, as different membrane orientations of RAS expose distinct putative dimerization interfaces.
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Affiliation(s)
- Timothy Travers
- Theoretical Biology and Biophysics Group, Los Alamos National Laboratory, Los Alamos, New Mexico, 87545, United States
- Center for Nonlinear Studies, Los Alamos National Laboratory, Los Alamos, New Mexico, 87545, United States
| | - Cesar A López
- Theoretical Biology and Biophysics Group, Los Alamos National Laboratory, Los Alamos, New Mexico, 87545, United States
| | - Que N Van
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc., Frederick, Maryland, 21702, United States
| | - Chris Neale
- Center for Nonlinear Studies, Los Alamos National Laboratory, Los Alamos, New Mexico, 87545, United States
| | - Marco Tonelli
- National Magnetic Resource Facility at Madison, Biochemistry Department, University of Wisconsin-Madison, Madison, Wisconsin, 53706, United States
| | - Andrew G Stephen
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc., Frederick, Maryland, 21702, United States
| | - S Gnanakaran
- Theoretical Biology and Biophysics Group, Los Alamos National Laboratory, Los Alamos, New Mexico, 87545, United States.
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Schöpel M, Shkura O, Seidel J, Kock K, Zhong X, Löffek S, Helfrich I, Bachmann HS, Scherkenbeck J, Herrmann C, Stoll R. Allosteric Activation of GDP-Bound Ras Isoforms by Bisphenol Derivative Plasticisers. Int J Mol Sci 2018; 19:ijms19041133. [PMID: 29642594 PMCID: PMC5979466 DOI: 10.3390/ijms19041133] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Revised: 04/04/2018] [Accepted: 04/05/2018] [Indexed: 01/13/2023] Open
Abstract
The protein family of small GTPases controls cellular processes by acting as a binary switch between an active and an inactive state. The most prominent family members are H-Ras, N-Ras, and K-Ras isoforms, which are highly related and frequently mutated in cancer. Bisphenols are widespread in modern life because of their industrial application as plasticisers. Bisphenol A (BPA) is the best-known member and has gained significant scientific as well as public attention as an endocrine disrupting chemical, a fact that eventually led to its replacement. However, compounds used to replace BPA still contain the molecular scaffold of bisphenols. BPA, BPAF, BPB, BPE, BPF, and an amine-substituted BPAF-derivate all interact with all GDP-bound Ras-Isoforms through binding to a common site on these proteins. NMR-, SOScat-, and GDI- assay-based data revealed a new bisphenol-induced, allosterically activated GDP-bound Ras conformation that define these plasticisers as Ras allosteric agonists.
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Affiliation(s)
- Miriam Schöpel
- Faculty of Chemistry and Biochemistry, Ruhr University of Bochum, Universitätsstr. 150, D-44780 Bochum, Germany.
| | - Oleksandr Shkura
- Faculty of Chemistry and Biochemistry, Ruhr University of Bochum, Universitätsstr. 150, D-44780 Bochum, Germany.
| | - Jana Seidel
- Faculty of Chemistry and Biochemistry, Ruhr University of Bochum, Universitätsstr. 150, D-44780 Bochum, Germany.
| | - Klaus Kock
- Faculty of Chemistry and Biochemistry, Ruhr University of Bochum, Universitätsstr. 150, D-44780 Bochum, Germany.
| | - Xueyin Zhong
- Faculty of Chemistry and Biochemistry, Ruhr University of Bochum, Universitätsstr. 150, D-44780 Bochum, Germany.
| | - Stefanie Löffek
- Skin Cancer Unit of the Dermatology Department, West German Cancer Center, University Hospital Essen, University Duisburg-Essen and the German Cancer Consortium (DKTK), D-45147 Essen, Germany.
| | - Iris Helfrich
- Skin Cancer Unit of the Dermatology Department, West German Cancer Center, University Hospital Essen, University Duisburg-Essen and the German Cancer Consortium (DKTK), D-45147 Essen, Germany.
| | - Hagen S Bachmann
- Institute of Pharmacology and Toxicology, Witten/Herdecke University, Stockumer Str. 10, D-58453 Witten, Germany.
| | - Jürgen Scherkenbeck
- Faculty of Mathematics and Natural Sciences, University of Wuppertal, Gaußstr. 20, D-42119 Wuppertal, Germany.
| | - Christian Herrmann
- Faculty of Chemistry and Biochemistry, Ruhr University of Bochum, Universitätsstr. 150, D-44780 Bochum, Germany.
| | - Raphael Stoll
- Faculty of Chemistry and Biochemistry, Ruhr University of Bochum, Universitätsstr. 150, D-44780 Bochum, Germany.
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Podkalicka J, Biernatowska A, Olszewska P, Tabaczar S, Sikorski AF. The microdomain-organizing protein MPP1 is required for insulin-stimulated activation of H-Ras. Oncotarget 2018; 9:18410-18421. [PMID: 29719614 PMCID: PMC5915081 DOI: 10.18632/oncotarget.24847] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Accepted: 02/27/2018] [Indexed: 12/21/2022] Open
Abstract
Signaling complexes are localized to distinct plasma-membrane domains which undergo precise spatiotemporal regulation. A crucial link between membrane dynamics and the small GTPase, H-Ras, has been suggested, connecting membrane localization, clustering and scaffolding with its activity and signal transduction. Results of this study suggest a relationship between MPP1 and/or MPP1-dependent plasma-membrane organization and H-Ras activation. Namely, we show here that in HEL cells, MPP1 knock-down lead to the disruption of signaling cascade(s) from the activated insulin receptor. The signal inhibition occurred at the level of H-Ras, as it showed impaired GDP-to-GTP exchange and further interaction with its effector molecule, Raf. Moreover, in these cells H-Ras detergent-resistant membrane localization was not sensitive to insulin treatment which may imply molecular mechanism via which MPP1 affects functions of other proteins which may be connected with functional domain formation. Understanding the link between MPP1 and activation of H-Ras, may provide an important insight into the complexity of Ras related signaling pathways which may become a potential target for associated cancer therapies.
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Affiliation(s)
- Joanna Podkalicka
- Laboratory of Cytobiochemistry, Faculty of Biotechnology, University of Wrocław, 50-383 Wrocław, Poland
| | - Agnieszka Biernatowska
- Laboratory of Cytobiochemistry, Faculty of Biotechnology, University of Wrocław, 50-383 Wrocław, Poland
| | - Paulina Olszewska
- Laboratory of Cytobiochemistry, Faculty of Biotechnology, University of Wrocław, 50-383 Wrocław, Poland
| | - Sabina Tabaczar
- Laboratory of Cytobiochemistry, Faculty of Biotechnology, University of Wrocław, 50-383 Wrocław, Poland
| | - Aleksander F Sikorski
- Laboratory of Cytobiochemistry, Faculty of Biotechnology, University of Wrocław, 50-383 Wrocław, Poland
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43
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Li S, Jang H, Zhang J, Nussinov R. Raf-1 Cysteine-Rich Domain Increases the Affinity of K-Ras/Raf at the Membrane, Promoting MAPK Signaling. Structure 2018; 26:513-525.e2. [PMID: 29429878 PMCID: PMC8183739 DOI: 10.1016/j.str.2018.01.011] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Revised: 11/08/2017] [Accepted: 01/12/2018] [Indexed: 12/30/2022]
Abstract
K-Ras4B preferentially activates Raf-1. The high-affinity interaction of Ras-binding domain (RBD) of Raf with Ras was solved, but the relative position of Raf's cysteine-rich domain (CRD) in the Ras/Raf complex at the membrane and key question of exactly how it affects Raf signaling are daunting. We show that CRD stably binds anionic membranes inserting a positively charged loop into the amphipathic interface. Importantly, when in complex with Ras/RBD, covalently connected CRD presents the same membrane interaction mechanism, with CRD locating at the space between the RBD and membrane. To date, CRD's role was viewed in terms of stabilizing Raf-membrane interaction. Our observations argue for a key role in reducing Ras/RBD fluctuations at the membrane, thereby increasing Ras/RBD affinity. Even without K-Ras, via CRD, Raf-1 can recruit to the membrane; however, by reducing the Ras/RBD fluctuations and enhancing Ras/RBD affinity at the membrane, CRD promotes Raf's activation and MAPK signaling over other pathways.
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Affiliation(s)
- Shuai Li
- Department of Pathophysiology, Shanghai Universities E-Institute for Chemical Biology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University, School of Medicine, Shanghai 200025, China
| | - Hyunbum Jang
- Cancer and Inflammation Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, National Cancer Institute at Frederick, Frederick, MD 21702, USA
| | - Jian Zhang
- Department of Pathophysiology, Shanghai Universities E-Institute for Chemical Biology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University, School of Medicine, Shanghai 200025, China
| | - Ruth Nussinov
- Cancer and Inflammation Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, National Cancer Institute at Frederick, Frederick, MD 21702, USA; Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel.
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44
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Nguyen B, Hartich D, Seifert U, Rios PDL. Thermodynamic Bounds on the Ultra- and Infra-affinity of Hsp70 for Its Substrates. Biophys J 2017; 113:362-370. [PMID: 28746847 DOI: 10.1016/j.bpj.2017.06.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Revised: 05/31/2017] [Accepted: 06/09/2017] [Indexed: 12/16/2022] Open
Abstract
The 70 kDa heat shock protein Hsp70 has several essential functions in living systems, such as protecting cells against protein aggregation, assisting protein folding, remodeling protein complexes, and driving translocation into organelles. These functions require high affinity for nonspecific amino acid sequences that are ubiquitous in proteins. It has been recently shown that this high affinity, called ultra-affinity, depends on a process driven out of equilibrium by ATP hydrolysis. Here, we establish the thermodynamic bounds for ultra-affinity, and further show that the same reaction scheme can in principle be used both to strengthen and to weaken affinities (leading in this case to infra-affinity). We show that cofactors are essential to achieve affinity beyond the equilibrium range. Finally, biological implications are discussed.
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Affiliation(s)
- Basile Nguyen
- II. Institut für Theoretische Physik, Universität Stuttgart, Stuttgart, Germany; Laboratory of Statistical Biophysics, Institute of Physics, School of Basic Science and Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.
| | - David Hartich
- II. Institut für Theoretische Physik, Universität Stuttgart, Stuttgart, Germany
| | - Udo Seifert
- II. Institut für Theoretische Physik, Universität Stuttgart, Stuttgart, Germany
| | - Paolo De Los Rios
- Laboratory of Statistical Biophysics, Institute of Physics, School of Basic Science and Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
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45
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Ke H, Matsumoto S, Murashima Y, Taniguchi-Tamura H, Miyamoto R, Yoshikawa Y, Tsuda C, Kumasaka T, Mizohata E, Edamatsu H, Kataoka T. Structural basis for intramolecular interaction of post-translationally modified H-Ras•GTP prepared by protein ligation. FEBS Lett 2017; 591:2470-2481. [PMID: 28730604 DOI: 10.1002/1873-3468.12759] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Revised: 07/09/2017] [Accepted: 07/10/2017] [Indexed: 01/26/2023]
Abstract
Ras undergoes post-translational modifications including farnesylation, proteolysis, and carboxymethylation at the C terminus, which are necessary for membrane recruitment and effector recognition. Full activation of c-Raf-1 requires cooperative interaction of the farnesylated C terminus and the activator region of Ras with its cysteine-rich domain (CRD). However, the molecular basis for this interaction remains unclear because of difficulties in preparing modified Ras in amounts sufficient for structural studies. Here, we use Sortase A-catalyzed protein ligation to prepare modified Ras in sufficient amounts for NMR and X-ray crystallographic analyses. The results show that the farnesylated C terminus establishes an intramolecular interaction with the catalytic domain and brings the farnesyl moiety to the proximity of the activator region, which may be responsible for their cooperative recognition of c-Raf-1-CRD.
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Affiliation(s)
- Haoliang Ke
- Division of Molecular Biology, Department of Biochemistry and Molecular Biology, Kobe University Graduate School of Medicine, Chuo-ku, Kobe, Japan
| | - Shigeyuki Matsumoto
- Division of Molecular Biology, Department of Biochemistry and Molecular Biology, Kobe University Graduate School of Medicine, Chuo-ku, Kobe, Japan
| | - Yosuke Murashima
- Division of Molecular Biology, Department of Biochemistry and Molecular Biology, Kobe University Graduate School of Medicine, Chuo-ku, Kobe, Japan
| | - Haruka Taniguchi-Tamura
- Division of Molecular Biology, Department of Biochemistry and Molecular Biology, Kobe University Graduate School of Medicine, Chuo-ku, Kobe, Japan
| | - Ryo Miyamoto
- Division of Molecular Biology, Department of Biochemistry and Molecular Biology, Kobe University Graduate School of Medicine, Chuo-ku, Kobe, Japan
| | - Yoko Yoshikawa
- Division of Molecular Biology, Department of Biochemistry and Molecular Biology, Kobe University Graduate School of Medicine, Chuo-ku, Kobe, Japan
| | - Chiemi Tsuda
- Division of Molecular Biology, Department of Biochemistry and Molecular Biology, Kobe University Graduate School of Medicine, Chuo-ku, Kobe, Japan
| | - Takashi Kumasaka
- Japan Synchrotron Radiation Research Institute (JASRI), Sayo-gun, Hyogo, Japan
| | - Eiichi Mizohata
- Department of Applied Chemistry, Graduate School of Engineering, Osaka University, Suita, Osaka, Japan
| | - Hironori Edamatsu
- Division of Molecular Biology, Department of Biochemistry and Molecular Biology, Kobe University Graduate School of Medicine, Chuo-ku, Kobe, Japan
| | - Tohru Kataoka
- Division of Molecular Biology, Department of Biochemistry and Molecular Biology, Kobe University Graduate School of Medicine, Chuo-ku, Kobe, Japan
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Messina S, Di Zazzo E, Moncharmont B. Early and Late Induction of KRAS and HRAS Proto-Oncogenes by Reactive Oxygen Species in Primary Astrocytes. Antioxidants (Basel) 2017; 6:antiox6030048. [PMID: 28661467 PMCID: PMC5618076 DOI: 10.3390/antiox6030048] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Revised: 06/17/2017] [Accepted: 06/19/2017] [Indexed: 12/13/2022] Open
Abstract
Astrocytes, one of the predominant types of glial cells, function as both supportive and metabolic cells for the brain. Among mammalian tissues, the highest levels of p21Ras protein are detected in the brain. Here, we investigated the expression of KRAS and HRAS proto-oncogenes in primary astrocytes following acute oxidative stimulation. Reactive oxygen species (ROS) changed the expression of proto-oncogenes at both transcriptional and translational levels. De novo protein synthesis analysis measured approximate values of proteins half-life, ranging from 1–4 h, of the different H- and K- isoforms by western blot analysis. Quantitative gene expression analysis of KRAS and HRAS revealed an unexpected short-term induction of KRAS mRNA in primary astrocytes in response to acute stimulation. Indeed, cultured astrocytes responded to proteasomal inhibition by preventing the reduction of c-K-Ras. A fraction of K-Ras protein accumulated in the presence of ROS and cycloheximide, while a substantial proportion was continuously synthesized. These data indicate that ROS regulate in a complementary fashion p21Ras isoforms in primary astrocytes: K-Ras is rapidly and transiently induced by post-translational and post-transcriptional mechanisms, while H-Ras is stably induced by mRNA accumulation. We suggest that K-Ras and H-Ras are ROS sensors that adapt cells to metabolic needs and oxidative stress.
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Affiliation(s)
- Samantha Messina
- Department of Human Sciences, Society and Health, University of Cassino and Southern Lazio, Cassino 03043, Italy.
| | - Erika Di Zazzo
- Department of Medicine and Health Sciences "Vincenzo Tiberio", University of Molise, Campobasso 86100, Italy.
| | - Bruno Moncharmont
- Department of Medicine and Health Sciences "Vincenzo Tiberio", University of Molise, Campobasso 86100, Italy.
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Sayyed-Ahmad A, Prakash P, Gorfe AA. Distinct dynamics and interaction patterns in H- and K-Ras oncogenic P-loop mutants. Proteins 2017; 85:1618-1632. [PMID: 28498561 DOI: 10.1002/prot.25317] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2017] [Revised: 04/27/2017] [Accepted: 05/05/2017] [Indexed: 12/31/2022]
Abstract
Despite years of study, the structural or dynamical basis for the differential reactivity and oncogenicity of Ras isoforms and mutants remains unclear. In this study, we investigated the effects of amino acid variations on the structure and dynamics of wild type and oncogenic mutants G12D, G12V, and G13D of H- and K-Ras proteins. Based on data from µs-scale molecular dynamics simulations, we show that the overall structure of the proteins remains similar but there are important differences in dynamics and interaction networks. We identified differences in residue interaction patterns around the canonical switch and distal loop regions, and persistent sodium ion binding near the GTP particularly in the G13D mutants. Our results also suggest that different Ras variants have distinct local structural features and interactions with the GTP, variations that have the potential to affect GTP release and hydrolysis. Furthermore, we found that H-Ras proteins and particularly the G12V and G13D variants are significantly more flexible than their K-Ras counterparts. Finally, while most of the simulated proteins sampled the effector-interacting state 2 conformational state, G12V and G13D H-Ras adopted an open switch state 1 conformation that is defective in effector interaction. These differences have implications for Ras GTPase activity, effector or exchange factor binding, dimerization and membrane interaction. Proteins 2017; 85:1618-1632. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Abdallah Sayyed-Ahmad
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston, Houston, Texas, 77030
| | - Priyanka Prakash
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston, Houston, Texas, 77030
| | - Alemayehu A Gorfe
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston, Houston, Texas, 77030
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48
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Koturenkiene A, Makbul C, Herrmann C, Constantinescu-Aruxandei D. Kinetic characterization of apoptotic Ras signaling through Nore1-MST1 complex formation. Biol Chem 2017; 398:701-707. [PMID: 28141542 DOI: 10.1515/hsz-2016-0291] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Accepted: 01/24/2017] [Indexed: 01/13/2023]
Abstract
Ras-mediated apoptotic signaling is expected to be mediated via Rassf-MST complexes, but the system has been poorly characterized in vitro until now. Here we demonstrate that active H-Ras, Nore1A and MST1 form a stable ternary complex in vitro without other external factors, Nore1A interacting simultaneously with H-Ras and MST1 via its RBD and SARAH domain, respectively. Moreover, our data show for the first time that the SARAH domain of Nore1A plays a role in the Nore1A binding to H-Ras. Finally, we analyze the relation between the electrostatic and hydrophobic forces and kinetic constants of the Nore1A - H-Ras complex.
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Affiliation(s)
- Agne Koturenkiene
- Department of Physical Chemistry I, Ruhr University Bochum, Universitätsstraße 150, D-44780 Bochum
| | - Cihan Makbul
- Department of Physical Chemistry I, Ruhr University Bochum, Universitätsstraße 150, D-44780 Bochum
| | - Christian Herrmann
- Department of Physical Chemistry I, Ruhr University Bochum, Universitätsstraße 150, D-44780 Bochum
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Nakhaeizadeh H, Amin E, Nakhaei-Rad S, Dvorsky R, Ahmadian MR. The RAS-Effector Interface: Isoform-Specific Differences in the Effector Binding Regions. PLoS One 2016; 11:e0167145. [PMID: 27936046 PMCID: PMC5147862 DOI: 10.1371/journal.pone.0167145] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Accepted: 11/09/2016] [Indexed: 12/31/2022] Open
Abstract
RAS effectors specifically interact with the GTP-bound form of RAS in response to extracellular signals and link them to downstream signaling pathways. The molecular nature of effector interaction by RAS is well-studied but yet still incompletely understood in a comprehensive and systematic way. Here, structure-function relationships in the interaction between different RAS proteins and various effectors were investigated in detail by combining our in vitro data with in silico data. Equilibrium dissociation constants were determined for the binding of HRAS, KRAS, NRAS, RRAS1 and RRAS2 to both the RAS binding (RB) domain of CRAF and PI3Kα, and the RAS association (RA) domain of RASSF5, RALGDS and PLCε, respectively, using fluorescence polarization. An interaction matrix, constructed on the basis of available crystal structures, allowed identification of hotspots as critical determinants for RAS-effector interaction. New insights provided by this study are the dissection of the identified hotspots in five distinct regions (R1 to R5) in spite of high sequence variability not only between, but also within, RB/RA domain-containing effectors proteins. Finally, we propose that intermolecular β-sheet interaction in R1 is a central recognition region while R3 may determine specific contacts of RAS versus RRAS isoforms with effectors.
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Affiliation(s)
- Hossein Nakhaeizadeh
- Institute of Biochemistry and Molecular Biology II, Medical Faculty of the Heinrich-Heine University, Düsseldorf, Germany
| | - Ehsan Amin
- Institute of Biochemistry and Molecular Biology II, Medical Faculty of the Heinrich-Heine University, Düsseldorf, Germany
| | - Saeideh Nakhaei-Rad
- Institute of Biochemistry and Molecular Biology II, Medical Faculty of the Heinrich-Heine University, Düsseldorf, Germany
| | - Radovan Dvorsky
- Institute of Biochemistry and Molecular Biology II, Medical Faculty of the Heinrich-Heine University, Düsseldorf, Germany
| | - Mohammad Reza Ahmadian
- Institute of Biochemistry and Molecular Biology II, Medical Faculty of the Heinrich-Heine University, Düsseldorf, Germany
- * E-mail:
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50
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L'RRK de Triomphe: a solution for LRRK2 GTPase activity? Biochem Soc Trans 2016; 44:1625-1634. [DOI: 10.1042/bst20160240] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Revised: 09/15/2016] [Accepted: 09/23/2016] [Indexed: 01/01/2023]
Abstract
Leucine-rich repeat kinase 2 (LRRK2) is a central protein in the pathogenesis of Parkinson's disease (PD), yet its normal function has proved stubbornly hard to elucidate. Even though it remains unclear how pathogenic mutations affect LRRK2 to cause PD, recent findings provide increasing cause for optimism. We summarise here the developing consensus over the effect of pathogenic mutations in the Ras of complex proteins and C-terminal of Roc domains on LRRK2 GTPase activity. This body of work has been greatly reinforced by our own study of the protective R1398H variant contained within the LRRK2 GTPase domain. Collectively, data point towards the pathogenicity of GTP-bound LRRK2 and strengthen a working model for LRRK2 GTPase function as a GTPase activated by dimerisation. Together with the identification of the protective R1398H variant as a valuable control for pathogenic mutations, we have no doubt that these triumphs for the LRRK2 field will accelerate research towards resolving LRRK2 function and towards new treatments for PD.
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