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Henkels KM, Miller TE, Naji A, van der Hoeven R, Liang H, Zhou Y, Hammond GR, Hancock JF, Cho KJ. Myotubularin-related proteins regulate KRAS function by controlling plasma membrane levels of polyphosphoinositides and phosphatidylserine. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.22.576612. [PMID: 38328115 PMCID: PMC10849561 DOI: 10.1101/2024.01.22.576612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2024]
Abstract
KRAS is a small GTPase, ubiquitously expressed in mammalian cells, that functions as a molecular switch to regulate cell proliferation and differentiation. Oncogenic mutations that render KRAS constitutively active occur frequently in human cancers. KRAS must localize to the plasma membrane (PM) for biological activity. KRAS PM binding is mediated by interactions of the KRAS membrane anchor with phosphatidylserine (PtdSer), therefore, depleting PM PtdSer content abrogates KRAS PM binding and oncogenic function. From a genome-wide siRNA screen to search for genes that regulate KRAS PM localization, we identified a set of phosphatidylinositol (PI) 3-phosphatase family members: myotubularin-related (MTMR) proteins 2, 3, 4 and 7. Here we show that knockdown of MTMR 2/3/4/7 expression disrupts KRAS PM interactions. The molecular mechanism involves depletion of PM PI 4-phosphate (PI4P) levels, which in turn disrupts the subcellular localization and operation of oxysterol-binding protein related protein (ORP) 5, a PtdSer lipid transfer protein that maintains PM PtdSer content. Concomitantly, silencing MTMR 2/3/4/7 expression elevates PM levels of PI3P and reduces PM and total cellular levels of PtdSer. In summary we propose that the PI 3-phosphatase activity provided by MTMR proteins is required to generate PM PI for the synthesis of PM PI4P, which in turn, promotes the PM localization of PtdSer and KRAS.
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Affiliation(s)
- Karen M. Henkels
- Department of Biochemistry and Molecular Biology, Boonshoft School of Medicine, Wright State University, Dayton, Ohio 45435, USA
| | - Taylor E. Miller
- Department of Biochemistry and Molecular Biology, Boonshoft School of Medicine, Wright State University, Dayton, Ohio 45435, USA
| | - Ali Naji
- Department of Diagnostic and Biomedical Sciences, School of Dentistry, The University of Texas Health Science Center at Houston, Houston, Texas 77030, USA
| | - Ransome van der Hoeven
- Department of Diagnostic and Biomedical Sciences, School of Dentistry, The University of Texas Health Science Center at Houston, Houston, Texas 77030, USA
| | - Hong Liang
- Department of Integrative Biology and Pharmacology, McGovern Medical School, University of Texas Health Science Center, Houston, Texas 77030, USA
| | - Yong Zhou
- Department of Integrative Biology and Pharmacology, McGovern Medical School, University of Texas Health Science Center, Houston, Texas 77030, USA
| | - Gerald R.V. Hammond
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - John F. Hancock
- Department of Integrative Biology and Pharmacology, McGovern Medical School, University of Texas Health Science Center, Houston, Texas 77030, USA
| | - Kwang-jin Cho
- Department of Biochemistry and Molecular Biology, Boonshoft School of Medicine, Wright State University, Dayton, Ohio 45435, USA
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2
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Chen PY, Huang BJ, Harris M, Boone C, Wang W, Carias H, Mesiona B, Mavrici D, Kohler AC, Bollag G, Zhang C, Zhang Y, Shannon K. Structural and functional analyses of a germline KRAS T50I mutation provide insights into Raf activation. JCI Insight 2023; 8:e168445. [PMID: 37681415 PMCID: PMC10544224 DOI: 10.1172/jci.insight.168445] [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: 01/04/2023] [Accepted: 08/02/2023] [Indexed: 09/09/2023] Open
Abstract
A T50I substitution in the K-Ras interswitch domain causes Noonan syndrome and emerged as a third-site mutation that restored the in vivo transforming activity and constitutive MAPK pathway activation by an attenuated KrasG12D,E37G oncogene in a mouse leukemia model. Biochemical and crystallographic data suggested that K-RasT50I increases MAPK signal output through a non-GTPase mechanism, potentially by promoting asymmetric Ras:Ras interactions between T50 and E162. We generated a "switchable" system in which K-Ras mutant proteins expressed at physiologic levels supplant the fms like tyrosine kinase 3 (FLT3) dependency of MOLM-13 leukemia cells lacking endogenous KRAS and used this system to interrogate single or compound G12D, T50I, D154Q, and E162L mutations. These studies support a key role for the asymmetric lateral assembly of K-Ras in a plasma membrane-distal orientation that promotes the formation of active Ras:Raf complexes in a membrane-proximal conformation. Disease-causing mutations such as T50I are a valuable starting point for illuminating normal Ras function, elucidating mechanisms of disease, and identifying potential therapeutic opportunities for Rasopathy disorders and cancer.
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Affiliation(s)
- Pan-Yu Chen
- Department of Pediatrics, UCSF, San Francisco, California, USA
| | | | - Max Harris
- Department of Pediatrics, UCSF, San Francisco, California, USA
| | | | - Weijie Wang
- Department of Pediatrics, UCSF, San Francisco, California, USA
| | - Heidi Carias
- Plexxikon Inc., South San Francisco, California, USA
| | - Brian Mesiona
- Plexxikon Inc., South San Francisco, California, USA
| | | | | | - Gideon Bollag
- Plexxikon Inc., South San Francisco, California, USA
| | - Chao Zhang
- Plexxikon Inc., South San Francisco, California, USA
| | - Ying Zhang
- Plexxikon Inc., South San Francisco, California, USA
| | - Kevin Shannon
- Department of Pediatrics, UCSF, San Francisco, California, USA
- Helen Diller Family Comprehensive Cancer Center, UCSF, San Francisco, California, USA
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3
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Pavic K, Chippalkatti R, Abankwa D. Drug targeting opportunities en route to Ras nanoclusters. Adv Cancer Res 2022; 153:63-99. [PMID: 35101236 DOI: 10.1016/bs.acr.2021.07.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Disruption of the native membrane organization of Ras by the farnesyltransferase inhibitor tipifarnib in the late 1990s constituted the first indirect approach to drug target Ras. Since then, our understanding of how dynamically Ras shuttles between subcellular locations has changed significantly. Ras proteins have to arrive at the plasma membrane for efficient MAPK-signal propagation. On the plasma membrane Ras proteins are organized into isoform specific proteo-lipid assemblies called nanocluster. Recent evidence suggests that Ras nanocluster have a specific lipid composition, which supports the recruitment of effectors such as Raf. Conversely, effectors possess lipid-recognition motifs, which appear to serve as co-incidence detectors for the lipid domain of a given Ras isoform. Evidence suggests that dimeric Raf proteins then co-assemble dimeric Ras in an immobile complex, thus forming the minimal unit of an active nanocluster. Here we review established and novel trafficking chaperones and trafficking factors of Ras, along with the set of lipid and protein modulators of Ras nanoclustering. We highlight drug targeting approaches and opportunities against these determinants of functional Ras membrane organization. Finally, we reflect on implications for Ras signaling in polarized cells, such as epithelia, which are a common origin of tumorigenesis.
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Affiliation(s)
- Karolina Pavic
- Cancer Cell Biology and Drug Discovery Group, Department of Life Sciences and Medicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Rohan Chippalkatti
- Cancer Cell Biology and Drug Discovery Group, Department of Life Sciences and Medicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Daniel Abankwa
- Cancer Cell Biology and Drug Discovery Group, Department of Life Sciences and Medicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg.
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4
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Fuentes NR, Salinas ML, Wang X, Fan YY, Chapkin RS. Assessment of Plasma Membrane Fatty Acid Composition and Fluidity Using Imaging Flow Cytometry. METHODS IN MOLECULAR BIOLOGY (CLIFTON, N.J.) 2021; 2262:251-258. [PMID: 33977481 DOI: 10.1007/978-1-0716-1190-6_14] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Phospholipid fatty acid (FA) composition influences the biophysical properties of the plasma membrane and plays an important role in cellular signaling. Our previous work has demonstrated that plasma membrane fatty acid composition is an important determinant of oncogenic Ras signaling and that dietary (exogenous) modulation of membrane composition may underlie the chemoprotective benefits of long chain n-3 polyunsaturated fatty acids (PUFA). In this chapter, we describe in vitro methods to modulate membrane phospholipid fatty acid composition of cultured cells using fatty acids complexed to bovine serum albumin (BSA). Furthermore, we describe a method to quantify the biophysical properties of plasma membranes in live cells using Di-4-ANEPPDHQ (Di4) and image-based flow cytometry.
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Affiliation(s)
- Natividad R Fuentes
- Program in Integrative Nutrition and Complex Diseases, Texas A&M University, College Station, TX, USA
- Department of Nutrition, Texas A&M University, College Station, TX, USA
- Interdisciplinary Faculty of Toxicology, Texas A&M University, College Station, TX, USA
| | - Michael L Salinas
- Program in Integrative Nutrition and Complex Diseases, Texas A&M University, College Station, TX, USA
- Department of Nutrition, Texas A&M University, College Station, TX, USA
| | - Xiaoli Wang
- Program in Integrative Nutrition and Complex Diseases, Texas A&M University, College Station, TX, USA
- Department of Nutrition, Texas A&M University, College Station, TX, USA
| | - Yang-Yi Fan
- Program in Integrative Nutrition and Complex Diseases, Texas A&M University, College Station, TX, USA
- Department of Nutrition, Texas A&M University, College Station, TX, USA
| | - Robert S Chapkin
- Program in Integrative Nutrition and Complex Diseases, Texas A&M University, College Station, TX, USA.
- Department of Nutrition, Texas A&M University, College Station, TX, USA.
- Interdisciplinary Faculty of Toxicology, Texas A&M University, College Station, TX, USA.
- Center for Environmental Health Research, Texas A&M University, College Station, TX, USA.
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5
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Henkels KM, Rehl KM, Cho KJ. Blocking K-Ras Interaction With the Plasma Membrane Is a Tractable Therapeutic Approach to Inhibit Oncogenic K-Ras Activity. Front Mol Biosci 2021; 8:673096. [PMID: 34222333 PMCID: PMC8244928 DOI: 10.3389/fmolb.2021.673096] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Accepted: 05/20/2021] [Indexed: 12/12/2022] Open
Abstract
Ras proteins are membrane-bound small GTPases that promote cell proliferation, differentiation, and apoptosis. Consistent with this key regulatory role, activating mutations of Ras are present in ∼19% of new cancer cases in the United States per year. K-Ras is one of the three ubiquitously expressed isoforms in mammalian cells, and oncogenic mutations in this isoform account for ∼75% of Ras-driven cancers. Therefore, pharmacological agents that block oncogenic K-Ras activity would have great clinical utility. Most efforts to block oncogenic Ras activity have focused on Ras downstream effectors, but these inhibitors only show limited clinical benefits in Ras-driven cancers due to the highly divergent signals arising from Ras activation. Currently, four major approaches are being extensively studied to target K-Ras–driven cancers. One strategy is to block K-Ras binding to the plasma membrane (PM) since K-Ras requires the PM binding for its signal transduction. Here, we summarize recently identified molecular mechanisms that regulate K-Ras–PM interaction. Perturbing these mechanisms using pharmacological agents blocks K-Ras–PM binding and inhibits K-Ras signaling and growth of K-Ras–driven cancer cells. Together, these studies propose that blocking K-Ras–PM binding is a tractable strategy for developing anti–K-Ras therapies.
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Affiliation(s)
- Karen M Henkels
- Department of Biochemistry and Molecular Biology, School of Boonshoft School of Medicine, Wright State University, Dayton, OH, United States
| | - Kristen M Rehl
- Department of Biochemistry and Molecular Biology, School of Boonshoft School of Medicine, Wright State University, Dayton, OH, United States
| | - Kwang-Jin Cho
- Department of Biochemistry and Molecular Biology, School of Boonshoft School of Medicine, Wright State University, Dayton, OH, United States
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6
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Fuentes NR, Mlih M, Wang X, Webster G, Cortes-Acosta S, Salinas ML, Corbin IR, Karpac J, Chapkin RS. Membrane therapy using DHA suppresses epidermal growth factor receptor signaling by disrupting nanocluster formation. J Lipid Res 2021; 62:100026. [PMID: 33515553 PMCID: PMC7933808 DOI: 10.1016/j.jlr.2021.100026] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2020] [Revised: 01/11/2021] [Accepted: 01/19/2021] [Indexed: 02/07/2023] Open
Abstract
Epidermal growth factor receptor (EGFR) signaling drives the formation of many types of cancer, including colon cancer. Docosahexaenoic acid (DHA, 22∶6Δ4,7,10,13,16,19), a chemoprotective long-chain n-3 polyunsaturated fatty acid suppresses EGFR signaling. However, the mechanism underlying this phenotype remains unclear. Therefore, we used super-resolution microscopy techniques to investigate the mechanistic link between EGFR function and DHA-induced alterations to plasma membrane nanodomains. Using isogenic in vitro (YAMC and IMCE mouse colonic cell lines) and in vivo (Drosophila, wild type and Fat-1 mice) models, cellular DHA enrichment via therapeutic nanoparticle delivery, endogenous synthesis, or dietary supplementation reduced EGFR-mediated cell proliferation and downstream Ras/ERK signaling. Phospholipid incorporation of DHA reduced membrane rigidity and the size of EGFR nanoclusters. Similarly, pharmacological reduction of plasma membrane phosphatidic acid (PA), phosphatidylinositol-4,5-bisphosphate (PIP2) or cholesterol was associated with a decrease in EGFR nanocluster size. Furthermore, in DHA-treated cells only the addition of cholesterol, unlike PA or PIP2, restored EGFR nanoscale clustering. These findings reveal that DHA reduces EGFR signaling in part by reshaping EGFR proteolipid nanodomains, supporting the feasibility of using membrane therapy, i.e., dietary/drug-related strategies to target plasma membrane organization, to reduce EGFR signaling and cancer risk.
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Affiliation(s)
- Natividad R Fuentes
- Program in Integrative Nutrition and Complex Diseases, Texas A&M University, College Station, TX, USA; Department of Nutrition, Texas A&M University, College Station, TX, USA; Interdisciplinary Faculty of Toxicology, Texas A&M University, College Station, TX, USA
| | - Mohamed Mlih
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M Health Science Center, Bryan, TX, USA
| | - Xiaoli Wang
- Program in Integrative Nutrition and Complex Diseases, Texas A&M University, College Station, TX, USA; Department of Nutrition, Texas A&M University, College Station, TX, USA
| | - Gabriella Webster
- Program in Integrative Nutrition and Complex Diseases, Texas A&M University, College Station, TX, USA; Department of Nutrition, Texas A&M University, College Station, TX, USA
| | - Sergio Cortes-Acosta
- Program in Integrative Nutrition and Complex Diseases, Texas A&M University, College Station, TX, USA; Department of Nutrition, Texas A&M University, College Station, TX, USA
| | - Michael L Salinas
- Program in Integrative Nutrition and Complex Diseases, Texas A&M University, College Station, TX, USA; Department of Nutrition, Texas A&M University, College Station, TX, USA
| | - Ian R Corbin
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Jason Karpac
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M Health Science Center, Bryan, TX, USA
| | - Robert S Chapkin
- Program in Integrative Nutrition and Complex Diseases, Texas A&M University, College Station, TX, USA; Department of Nutrition, Texas A&M University, College Station, TX, USA; Interdisciplinary Faculty of Toxicology, Texas A&M University, College Station, TX, USA; Center for Translational Environmental Health Research, Texas A&M University, College Station, TX, USA.
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7
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Van QN, López CA, Tonelli M, Taylor T, Niu B, Stanley CB, Bhowmik D, Tran TH, Frank PH, Messing S, Alexander P, Scott D, Ye X, Drew M, Chertov O, Lösche M, Ramanathan A, Gross ML, Hengartner NW, Westler WM, Markley JL, Simanshu DK, Nissley DV, Gillette WK, Esposito D, McCormick F, Gnanakaran S, Heinrich F, Stephen AG. Uncovering a membrane-distal conformation of KRAS available to recruit RAF to the plasma membrane. Proc Natl Acad Sci U S A 2020; 117:24258-24268. [PMID: 32913056 PMCID: PMC7533834 DOI: 10.1073/pnas.2006504117] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The small GTPase KRAS is localized at the plasma membrane where it functions as a molecular switch, coupling extracellular growth factor stimulation to intracellular signaling networks. In this process, KRAS recruits effectors, such as RAF kinase, to the plasma membrane where they are activated by a series of complex molecular steps. Defining the membrane-bound state of KRAS is fundamental to understanding the activation of RAF kinase and in evaluating novel therapeutic opportunities for the inhibition of oncogenic KRAS-mediated signaling. We combined multiple biophysical measurements and computational methodologies to generate a consensus model for authentically processed, membrane-anchored KRAS. In contrast to the two membrane-proximal conformations previously reported, we identify a third significantly populated state using a combination of neutron reflectivity, fast photochemical oxidation of proteins (FPOP), and NMR. In this highly populated state, which we refer to as "membrane-distal" and estimate to comprise ∼90% of the ensemble, the G-domain does not directly contact the membrane but is tethered via its C-terminal hypervariable region and carboxymethylated farnesyl moiety, as shown by FPOP. Subsequent interaction of the RAF1 RAS binding domain with KRAS does not significantly change G-domain configurations on the membrane but affects their relative populations. Overall, our results are consistent with a directional fly-casting mechanism for KRAS, in which the membrane-distal state of the G-domain can effectively recruit RAF kinase from the cytoplasm for activation at the membrane.
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Affiliation(s)
- Que N Van
- National Cancer Institute RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc., Frederick, MD 21702
| | - Cesar A López
- Theoretical Biology and Biophysics Group, Los Alamos National Laboratory, Los Alamos, NM 87545
| | - Marco Tonelli
- National Magnetic Resonance Facility at Madison, Biochemistry Department, University of Wisconsin-Madison, Madison, WI 53706
| | - Troy Taylor
- National Cancer Institute RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc., Frederick, MD 21702
| | - Ben Niu
- National Mass Spectrometry Resource, Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130
| | - Christopher B Stanley
- Computational Sciences and Engineering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831
| | - Debsindhu Bhowmik
- Computational Sciences and Engineering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831
| | - Timothy H Tran
- National Cancer Institute RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc., Frederick, MD 21702
| | - Peter H Frank
- National Cancer Institute RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc., Frederick, MD 21702
| | - Simon Messing
- National Cancer Institute RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc., Frederick, MD 21702
| | - Patrick Alexander
- National Cancer Institute RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc., Frederick, MD 21702
| | - Daniel Scott
- Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, PA 15213
| | - Xiaoying Ye
- National Cancer Institute RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc., Frederick, MD 21702
| | - Matt Drew
- National Cancer Institute RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc., Frederick, MD 21702
| | - Oleg Chertov
- National Cancer Institute RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc., Frederick, MD 21702
| | - Mathias Lösche
- Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, PA 15213
- Department of Physics, Carnegie Mellon University, Pittsburgh, PA 15213
- Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899
| | - Arvind Ramanathan
- Data Science and Learning Division, Argonne National Laboratory, Lemont, IL 60439
| | - Michael L Gross
- National Mass Spectrometry Resource, Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130
| | - Nicolas W Hengartner
- Theoretical Biology and Biophysics Group, Los Alamos National Laboratory, Los Alamos, NM 87545
| | - William M Westler
- National Magnetic Resonance Facility at Madison, Biochemistry Department, University of Wisconsin-Madison, Madison, WI 53706
| | - John L Markley
- National Magnetic Resonance Facility at Madison, Biochemistry Department, University of Wisconsin-Madison, Madison, WI 53706
| | - Dhirendra K Simanshu
- National Cancer Institute RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc., Frederick, MD 21702
| | - Dwight V Nissley
- National Cancer Institute RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc., Frederick, MD 21702
| | - William K Gillette
- National Cancer Institute RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc., Frederick, MD 21702
| | - Dominic Esposito
- National Cancer Institute RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc., Frederick, MD 21702
| | - Frank McCormick
- National Cancer Institute RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc., Frederick, MD 21702;
| | - S Gnanakaran
- Theoretical Biology and Biophysics Group, Los Alamos National Laboratory, Los Alamos, NM 87545
| | - Frank Heinrich
- Department of Physics, Carnegie Mellon University, Pittsburgh, PA 15213
- Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899
| | - Andrew G Stephen
- National Cancer Institute RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc., Frederick, MD 21702;
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8
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Garrido CM, Henkels KM, Rehl KM, Liang H, Zhou Y, Gutterman JU, Cho KJ. Avicin G is a potent sphingomyelinase inhibitor and blocks oncogenic K- and H-Ras signaling. Sci Rep 2020; 10:9120. [PMID: 32499517 PMCID: PMC7272413 DOI: 10.1038/s41598-020-65882-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Accepted: 05/05/2020] [Indexed: 12/23/2022] Open
Abstract
K-Ras must interact primarily with the plasma membrane (PM) for its biological activity. Therefore, disrupting K-Ras PM interaction is a tractable approach to block oncogenic K-Ras activity. Here, we found that avicin G, a family of natural plant-derived triterpenoid saponins from Acacia victoriae, mislocalizes K-Ras from the PM and disrupts PM spatial organization of oncogenic K-Ras and H-Ras by depleting phosphatidylserine (PtdSer) and cholesterol contents, respectively, at the inner PM leaflet. Avicin G also inhibits oncogenic K- and H-Ras signal output and the growth of K-Ras-addicted pancreatic and non-small cell lung cancer cells. We further identified that avicin G perturbs lysosomal activity, and disrupts cellular localization and activity of neutral and acid sphingomyelinases (SMases), resulting in elevated cellular sphingomyelin (SM) levels and altered SM distribution. Moreover, we show that neutral SMase inhibitors disrupt the PM localization of K-Ras and PtdSer and oncogenic K-Ras signaling. In sum, this study identifies avicin G as a new potent anti-Ras inhibitor, and suggests that neutral SMase can be a tractable target for developing anti-K-Ras therapeutics.
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Affiliation(s)
- Christian M Garrido
- Department of Biochemistry and Molecular Biology, School of Boonshoft Medical School, Wright State University, Dayton, OH, 45435, United States
| | - Karen M Henkels
- Department of Biochemistry and Molecular Biology, School of Boonshoft Medical School, Wright State University, Dayton, OH, 45435, United States
| | - Kristen M Rehl
- Department of Biochemistry and Molecular Biology, School of Boonshoft Medical School, Wright State University, Dayton, OH, 45435, United States
| | - Hong Liang
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, 77030, United States
| | - Yong Zhou
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, 77030, United States
| | - Jordan U Gutterman
- Department of Systems Biology, The University of Texas M. D. Anderson Cancer Center, Houston, TX, 77030, United States
| | - Kwang-Jin Cho
- Department of Biochemistry and Molecular Biology, School of Boonshoft Medical School, Wright State University, Dayton, OH, 45435, United States.
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9
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Mehaffey MR, Schardon CL, Novelli ET, Cammarata MB, Webb LJ, Fast W, Brodbelt JS. Investigation of GTP-dependent dimerization of G12X K-Ras variants using ultraviolet photodissociation mass spectrometry. Chem Sci 2019; 10:8025-8034. [PMID: 31853358 PMCID: PMC6837035 DOI: 10.1039/c9sc01032g] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Accepted: 07/14/2019] [Indexed: 12/14/2022] Open
Abstract
Mutations in the GTPase enzyme K-Ras, specifically at codon G12, remain the most common genetic alterations in human cancers. The mechanisms governing activation of downstream signaling pathways and how they relate back to the identity of the mutation have yet to be completely defined. Here we use native mass spectrometry (MS) combined with ultraviolet photodissociation (UVPD) to investigate the impact of three G12X mutations (G12C, G12V, G12S) on the homodimerization of K-Ras as well as heterodimerization with a downstream effector protein, Raf. Electrospray ionization (ESI) was used to transfer complexes of WT or G12X K-Ras bound to guanosine 5'-diphosphate (GDP) or GppNHp (non-hydrolyzable analogue of GTP) into the gas phase. Relative abundances of homo- or hetero-dimer complexes were estimated from ESI-MS spectra. K-Ras + Raf heterocomplexes were activated with UVPD to probe structural changes responsible for observed differences in the amount of heterocomplex formed for each variant. Holo (ligand-bound) fragment ions resulting from photodissociation suggest the G12X mutants bind Raf along the expected effector binding region (β-interface) but may interact with Raf via an alternative α-interface as well. Variations in backbone cleavage efficiencies during UV photoactivation of each variant were used to relate mutation identity to structural changes that might impact downstream signaling. Specifically, oncogenic upregulation for hydrogen-bonding amino acid substitutions (G12C, G12S) is achieved by stabilizing β-interface interactions with Raf, while a bulkier, hydrophobic G12V substitution leads to destabilization of this interface and instead increases the proximity of residues along the α-helical bundles. This study deciphers new pieces of the complex puzzle of how different K-Ras mutations exert influence in downstream signaling.
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Affiliation(s)
- M Rachel Mehaffey
- Department of Chemistry , University of Texas at Austin , Austin , TX 78712-0165 , USA . ; Tel: +1-512-471-0028
| | - Christopher L Schardon
- Division of Chemical Biology and Medicinal Chemistry , College of Pharmacy , University of Texas at Austin , Austin , TX 78712 , USA
| | - Elisa T Novelli
- Department of Chemistry , University of Texas at Austin , Austin , TX 78712-0165 , USA . ; Tel: +1-512-471-0028
| | - Michael B Cammarata
- Department of Chemistry , University of Texas at Austin , Austin , TX 78712-0165 , USA . ; Tel: +1-512-471-0028
| | - Lauren J Webb
- Department of Chemistry , University of Texas at Austin , Austin , TX 78712-0165 , USA . ; Tel: +1-512-471-0028
| | - Walter Fast
- Division of Chemical Biology and Medicinal Chemistry , College of Pharmacy , University of Texas at Austin , Austin , TX 78712 , USA
| | - Jennifer S Brodbelt
- Department of Chemistry , University of Texas at Austin , Austin , TX 78712-0165 , USA . ; Tel: +1-512-471-0028
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10
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Functional link between plasma membrane spatiotemporal dynamics, cancer biology, and dietary membrane-altering agents. Cancer Metastasis Rev 2019; 37:519-544. [PMID: 29860560 DOI: 10.1007/s10555-018-9733-1] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The cell plasma membrane serves as a nexus integrating extra- and intracellular components, which together enable many of the fundamental cellular signaling processes that sustain life. In order to perform this key function, plasma membrane components assemble into well-defined domains exhibiting distinct biochemical and biophysical properties that modulate various signaling events. Dysregulation of these highly dynamic membrane domains can promote oncogenic signaling. Recently, it has been demonstrated that select membrane-targeted dietary bioactives (MTDBs) have the ability to remodel plasma membrane domains and subsequently reduce cancer risk. In this review, we focus on the importance of plasma membrane domain structural and signaling functionalities as well as how loss of membrane homeostasis can drive aberrant signaling. Additionally, we discuss the intricacies associated with the investigation of these membrane domain features and their associations with cancer biology. Lastly, we describe the current literature focusing on MTDBs, including mechanisms of chemoprevention and therapeutics in order to establish a functional link between these membrane-altering biomolecules, tuning of plasma membrane hierarchal organization, and their implications in cancer prevention.
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11
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Huang WYC, Alvarez S, Kondo Y, Lee YK, Chung JK, Lam HYM, Biswas KH, Kuriyan J, Groves JT. A molecular assembly phase transition and kinetic proofreading modulate Ras activation by SOS. Science 2019; 363:1098-1103. [PMID: 30846600 PMCID: PMC6563836 DOI: 10.1126/science.aau5721] [Citation(s) in RCA: 208] [Impact Index Per Article: 41.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 01/10/2019] [Indexed: 12/15/2022]
Abstract
The guanine nucleotide exchange factor (GEF) Son of Sevenless (SOS) is a key Ras activator that is autoinhibited in the cytosol and activates upon membrane recruitment. Autoinhibition release involves structural rearrangements of the protein at the membrane and thus introduces a delay between initial recruitment and activation. In this study, we designed a single-molecule assay to resolve the time between initial receptor-mediated membrane recruitment and the initiation of GEF activity of individual SOS molecules on microarrays of Ras-functionalized supported membranes. The rise-and-fall shape of the measured SOS activation time distribution and the long mean time scale to activation (~50 seconds) establish a basis for kinetic proofreading in the receptor-mediated activation of Ras. We further demonstrate that this kinetic proofreading is modulated by the LAT (linker for activation of T cells)-Grb2-SOS phosphotyrosine-driven phase transition at the membrane.
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Affiliation(s)
- William Y C Huang
- Department of Chemistry, University of California, Berkeley, CA 94720, USA
| | - Steven Alvarez
- Department of Materials Science and Engineering, University of California, Berkeley, CA 94720, USA
| | - Yasushi Kondo
- Department of Chemistry, University of California, Berkeley, CA 94720, USA
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA
- California Institute for Quantitative Biosciences, University of California, Berkeley, CA 94720, USA
| | - Young Kwang Lee
- Department of Chemistry, University of California, Berkeley, CA 94720, USA
| | - Jean K Chung
- Department of Chemistry, University of California, Berkeley, CA 94720, USA
| | | | - Kabir H Biswas
- Mechanobiology Institute, National University of Singapore, Singapore 117411, Singapore
| | - John Kuriyan
- Department of Chemistry, University of California, Berkeley, CA 94720, USA
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA
- California Institute for Quantitative Biosciences, University of California, Berkeley, CA 94720, USA
- Howard Hughes Medical Institute, University of California, Berkeley, CA 94720, USA
- Divisions of Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Jay T Groves
- Department of Chemistry, University of California, Berkeley, CA 94720, USA.
- California Institute for Quantitative Biosciences, University of California, Berkeley, CA 94720, USA
- Divisions of Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
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12
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Fuentes NR, Mlih M, Barhoumi R, Fan YY, Hardin P, Steele TJ, Behmer S, Prior IA, Karpac J, Chapkin RS. Long-Chain n-3 Fatty Acids Attenuate Oncogenic KRas-Driven Proliferation by Altering Plasma Membrane Nanoscale Proteolipid Composition. Cancer Res 2018; 78:3899-3912. [PMID: 29769200 DOI: 10.1158/0008-5472.can-18-0324] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2018] [Revised: 03/26/2018] [Accepted: 05/08/2018] [Indexed: 12/26/2022]
Abstract
Ras signaling originates from transient nanoscale compartmentalized regions of the plasma membrane composed of specific proteins and lipids. The highly specific lipid composition of these nanodomains, termed nanoclusters, facilitates effector recruitment and therefore influences signal transduction. This suggests that Ras nanocluster proteolipid composition could represent a novel target for future chemoprevention interventions. There is evidence that consumption of fish oil containing long-chain n-3 polyunsaturated fatty acids (n-3 PUFA) such as eicosapentaenoic acid (EPA, 20:5Δ5,8,11,14,17) and docosahexaenoic acid (DHA, 22:6Δ4,7,10,13,16,19) may reduce colon cancer risk in humans, yet the mechanism underlying this effect is unknown. Here, we demonstrate that dietary n-3 PUFA reduce the lateral segregation of cholesterol-dependent and -independent nanoclusters, suppressing phosphatidic acid-dependent oncogenic KRas effector interactions, via their physical incorporation into plasma membrane phospholipids. This results in attenuation of oncogenic Ras-driven colonic hyperproliferation in both Drosophila and murine models. These findings demonstrate the unique properties of dietary n-3 PUFA in the shaping of Ras nanoscale proteolipid complexes and support the emerging role of plasma membrane-targeted therapies.Significance: The influence of dietary long chain n-3 polyunsaturated fatty acids on plasma membrane protein nanoscale organization and KRas signaling supports development of plasma membrane-targeted therapies in colon cancer.Graphical Abstract: http://cancerres.aacrjournals.org/content/canres/78/14/3899/F1.large.jpg Cancer Res; 78(14); 3899-912. ©2018 AACR.
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Affiliation(s)
- Natividad R Fuentes
- Program in Integrative Nutrition and Complex Diseases, Texas A&M University, College Station, Texas.,Department of Veterinary Physiology and Pharmacology, Texas A&M University, College Station, Texas
| | - Mohamed Mlih
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M Health Sciences Center, College Station, Texas
| | - Rola Barhoumi
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas
| | - Yang-Yi Fan
- Program in Integrative Nutrition and Complex Diseases, Texas A&M University, College Station, Texas
| | - Paul Hardin
- Department of Biology, Texas A&M University, College Station, Texas
| | - Trevor J Steele
- Department of Entomology, Texas A&M University, College Station, Texas
| | - Spencer Behmer
- Department of Entomology, Texas A&M University, College Station, Texas
| | - Ian A Prior
- Division of Cellular and Molecular Physiology, University of Liverpool, Liverpool, United Kingdom
| | - Jason Karpac
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M Health Sciences Center, College Station, Texas
| | - Robert S Chapkin
- Program in Integrative Nutrition and Complex Diseases, Texas A&M University, College Station, Texas. .,Center for Translational Environmental Health Research, Texas A&M University, College Station, Texas
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13
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Chung JK, Lee YK, Denson JP, Gillette WK, Alvarez S, Stephen AG, Groves JT. K-Ras4B Remains Monomeric on Membranes over a Wide Range of Surface Densities and Lipid Compositions. Biophys J 2018; 114:137-145. [PMID: 29320680 PMCID: PMC5984903 DOI: 10.1016/j.bpj.2017.10.042] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Revised: 09/22/2017] [Accepted: 10/30/2017] [Indexed: 11/23/2022] Open
Abstract
Ras is a membrane-anchored signaling protein that serves as a hub for many signaling pathways and also plays a prominent role in cancer. The intrinsic behavior of Ras on the membrane has captivated the biophysics community in recent years, especially the possibility that it may form dimers. In this article, we describe results from a comprehensive series of experiments using fluorescence correlation spectroscopy and single-molecule tracking to probe the possible dimerization of natively expressed and fully processed K-Ras4B in supported lipid bilayer membranes. Key to these studies is the fact that K-Ras4B has its native membrane anchor, including both the farnesylation and methylation of the terminal cysteine, enabling detailed exploration of possible effects of cholesterol and lipid composition on K-Ras4B membrane organization. The results from all conditions studied indicate that full-length K-Ras4B lacks intrinsic dimerization capability. This suggests that any lateral organization of Ras in living cell membranes likely stems from interactions with other factors.
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Affiliation(s)
- Jean K Chung
- Department of Chemistry, University of California Berkeley, Berkeley, California
| | - Young Kwang Lee
- Department of Chemistry, University of California Berkeley, Berkeley, California
| | - John-Paul Denson
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc., Frederick, Maryland
| | - William K Gillette
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc., Frederick, Maryland
| | - Steven Alvarez
- Department of Materials Science and Engineering, University of California Berkeley, Berkeley, California
| | - Andrew G Stephen
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc., Frederick, Maryland
| | - Jay T Groves
- Department of Chemistry, University of California Berkeley, Berkeley, California.
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14
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Nussinov R, Tsai CJ, Jang H. A New View of Pathway-Driven Drug Resistance in Tumor Proliferation. Trends Pharmacol Sci 2017; 38:427-437. [PMID: 28245913 PMCID: PMC5403593 DOI: 10.1016/j.tips.2017.02.001] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Revised: 01/25/2017] [Accepted: 02/01/2017] [Indexed: 12/13/2022]
Abstract
Defeating drug resistance in tumor cell proliferation is challenging. We propose that signaling in cell proliferation takes place via two core pathways, each embodying multiple alternative pathways. We consider drug resistance through an alternative proliferation pathway - within the same or within the other core pathway. Most drug combinations target only one core pathway; blocking both can restrain proliferation. We define core pathways as independent and acting similarly in cell-cycle control, which can explain why their products (e.g., ERK and YAP1) can substitute for each other in resistance. Core pathways can forecast possible resistance because acquired resistance frequently occurs through alternative proliferation pathways. This concept may help to predict the efficacy of drug combinations. The selection of distinct combinations for specific mutated pathways would be guided by clinical diagnosis.
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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 21702, USA; Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, 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 21702, USA
| | - 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
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15
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Erwin N, Sperlich B, Garivet G, Waldmann H, Weise K, Winter R. Lipoprotein insertion into membranes of various complexity: lipid sorting, interfacial adsorption and protein clustering. Phys Chem Chem Phys 2017; 18:8954-62. [PMID: 26960984 DOI: 10.1039/c6cp00563b] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
In a combined chemical-biological and biophysical approach we explored the membrane partitioning of the lipidated signaling proteins N-Ras and K-Ras4B into membrane systems of different complexity, ranging from one-component lipid bilayers and anionic binary and ternary heterogeneous membrane systems even up to partitioning studies on protein-free and protein-containing giant plasma membrane vesicles (GPMVs). To yield a pictorial view of the localization process, imaging using confocal laser scanning and atomic force microscopy was performed. The results reveal pronounced isoform-specific differences regarding the lateral distribution and formation of protein-rich membrane domains. Line tension is one of the key parameters controlling not only the size and dynamic properties of segregated lipid domains but also the partitioning process of N-Ras that acts as a lineactant. The formation of N-Ras protein clusters is even recorded for almost vanishing hydrophobic mismatch. Conversely, for K-Ras4B, selective localization and clustering are electrostatically mediated by its polybasic farnesylated C-terminus. The formation of K-Ras4B clusters is also observed for the multi-component GPMV membrane, i.e., it seems to be a general phenomenon, largely independent of the details of the membrane composition, including the anionic charge density of lipid headgroups. Our data indicate that unspecific and entropy-driven membrane-mediated interactions play a major role in the partitioning behavior, thus relaxing the need for a multitude of fine-tuned interactions. Such a scenario seems also to be reasonable recalling the high dynamic nature of cellular membranes. Finally, we note that even relatively simple models of heterogeneous membranes are able to reproduce many of the properties of much more complex biological membranes.
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Affiliation(s)
- Nelli Erwin
- Faculty of Chemistry and Chemical Biology, Physical Chemistry I - Biophysical Chemistry, TU Dortmund University, D-44221 Dortmund, Germany.
| | - Benjamin Sperlich
- Faculty of Chemistry and Chemical Biology, Physical Chemistry I - Biophysical Chemistry, TU Dortmund University, D-44221 Dortmund, Germany.
| | - Guillaume Garivet
- Department of Chemical Biology, Max Planck Institute of Molecular Physiology, Otto-Hahn-Str. 11, D-44227 Dortmund, Germany and Faculty of Chemistry and Chemical Biology, Department of Chemical Biology, TU Dortmund University, D-44221 Dortmund, Germany
| | - Herbert Waldmann
- Department of Chemical Biology, Max Planck Institute of Molecular Physiology, Otto-Hahn-Str. 11, D-44227 Dortmund, Germany and Faculty of Chemistry and Chemical Biology, Department of Chemical Biology, TU Dortmund University, D-44221 Dortmund, Germany
| | - Katrin Weise
- Faculty of Chemistry and Chemical Biology, Physical Chemistry I - Biophysical Chemistry, TU Dortmund University, D-44221 Dortmund, Germany.
| | - Roland Winter
- Faculty of Chemistry and Chemical Biology, Physical Chemistry I - Biophysical Chemistry, TU Dortmund University, D-44221 Dortmund, Germany.
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16
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RASSF5: An MST activator and tumor suppressor in vivo but opposite in vitro. Curr Opin Struct Biol 2016; 41:217-224. [DOI: 10.1016/j.sbi.2016.09.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Accepted: 09/01/2016] [Indexed: 01/05/2023]
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17
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Abstract
Lipid-modified GTPases in the Ras superfamily that mediate a variety of cell signaling processes were thought to be passively anchored to membranes. However, an increasing number of recent studies are finding that membrane binding of these proteins is hardly a passive process, and it involves the soluble catalytic domain as well as the lipid anchor. The catalytic domain adopts multiple orientations on the membrane surface due to internal fluctuations that are modulated by activation status and mutations. Distinct orientation preferences among small GTPases likely lead to differential signaling outcomes, as downstream effectors can sense different orientations. We review recent studies behind this important conclusion.
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Affiliation(s)
- Priyanka Prakash
- a Department of Integrative Biology and Pharmacology , University of Texas Health Science Center at Houston , Houston , TX , USA
| | - Alemayehu A Gorfe
- a Department of Integrative Biology and Pharmacology , University of Texas Health Science Center at Houston , Houston , TX , USA
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18
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Tisza MJ, Zhao W, Fuentes JS, Prijic S, Chen X, Levental I, Chang JT. Motility and stem cell properties induced by the epithelial-mesenchymal transition require destabilization of lipid rafts. Oncotarget 2016; 7:51553-51568. [PMID: 27303921 PMCID: PMC5239496 DOI: 10.18632/oncotarget.9928] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Accepted: 05/23/2016] [Indexed: 01/06/2023] Open
Abstract
The Epithelial-Mesenchymal Transition (EMT) is a developmental program that provides cancer cells with the characteristics necessary for metastasis, including increased motility and stem cell properties. The cellular and molecular mechanisms underlying this process are not yet fully understood, hampering efforts to develop therapeutics. In recent years, it has become apparent that EMT is accompanied by wholesale changes in diverse signaling pathways that are initiated by proteins at the plasma membrane (PM). The PM contains thousands of lipid and protein species that are dynamically and spatially organized into lateral membrane domains, an example of which are lipid rafts. Since one of the major functions of rafts is modulation of signaling originating at the PM, we hypothesized that the signaling changes occurring during an EMT are associated with alterations in PM organization. To test this hypothesis, we used Giant Plasma Membrane Vesicles (GPMVs) to study the organization of intact plasma membranes isolated from live cells. We observed that induction of EMT significantly destabilized lipid raft domains. Further, this reduction in stability was crucial for the maintenance of the stem cell phenotype and EMT-induced remodeling of PM-orchestrated pathways. Exogenously increasing raft stability by feeding cells with ω-3 polyunsaturated fatty acid docosahexaenoic acid (DHA) repressed these phenotypes without altering EMT markers, and inhibited the metastatic capacity of breast cancer cells. Hence, modulating raft properties regulates cell phenotype, suggesting a novel approach for targeting the impact of EMT in cancer.
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Affiliation(s)
- Michael J. Tisza
- Department of Integrative Biology and Pharmacology, The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Weina Zhao
- Department of Integrative Biology and Pharmacology, The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Jessie S.R. Fuentes
- Department of Integrative Biology and Pharmacology, The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Sara Prijic
- Department of Integrative Biology and Pharmacology, The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Xiaoling Chen
- Department of Integrative Biology and Pharmacology, The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Ilya Levental
- Department of Integrative Biology and Pharmacology, The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Jeffrey T. Chang
- Department of Integrative Biology and Pharmacology, The University of Texas Health Science Center at Houston, Houston, TX, USA
- Department of Bioinformatics and Computational Biology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
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19
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Chavan TS, Muratcioglu S, Marszalek R, Jang H, Keskin O, Gursoy A, Nussinov R, Gaponenko V. Plasma membrane regulates Ras signaling networks. CELLULAR LOGISTICS 2015; 5:e1136374. [PMID: 27054048 PMCID: PMC4820813 DOI: 10.1080/21592799.2015.1136374] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 12/17/2015] [Indexed: 12/31/2022]
Abstract
Ras GTPases activate more than 20 signaling pathways, regulating such essential cellular functions as proliferation, survival, and migration. How Ras proteins control their signaling diversity is still a mystery. Several pieces of evidence suggest that the plasma membrane plays a critical role. Among these are: (1) selective recruitment of Ras and its effectors to particular localities allowing access to Ras regulators and effectors; (2) specific membrane-induced conformational changes promoting Ras functional diversity; and (3) oligomerization of membrane-anchored Ras to recruit and activate Raf. Taken together, the membrane does not only attract and retain Ras but also is a key regulator of Ras signaling. This can already be gleaned from the large variability in the sequences of Ras membrane targeting domains, suggesting that localization, environment and orientation are important factors in optimizing the function of Ras isoforms.
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Affiliation(s)
- Tanmay Sanjeev Chavan
- Department of Medicinal Chemistry; University of Illinois at Chicago; Chicago, IL USA
| | - Serena Muratcioglu
- Center for Computational Biology and Bioinformatics; Koc University; Istanbul, Turkey
| | - Richard Marszalek
- Department of Biochemistry and Molecular Genetics; University of Illinois at Chicago; Chicago, IL USA
| | - Hyunbum Jang
- Cancer and Inflammation Program; Basic Science Program; Leidos Biomedical Research, Inc.; Frederick National Laboratory for Cancer Research; National Cancer Institute at Frederick; Frederick, MD USA
| | - Ozlem Keskin
- Center for Computational Biology and Bioinformatics; Koc University; Istanbul, Turkey
| | - Attila Gursoy
- Center for Computational Biology and Bioinformatics; Koc University; Istanbul, Turkey
| | - Ruth Nussinov
- Cancer and Inflammation Program; Basic Science Program; Leidos Biomedical Research, Inc.; Frederick National Laboratory for Cancer Research; National Cancer Institute at Frederick; Frederick, MD USA
- Sackler Institute of Molecular Medicine; Department of Human Genetics and Molecular Medicine; Sackler School of Medicine; Tel Aviv University; Tel Aviv, Israel
| | - Vadim Gaponenko
- Department of Biochemistry and Molecular Genetics; University of Illinois at Chicago; Chicago, IL USA
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20
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Prakash P, Hancock JF, Gorfe AA. Binding hotspots on K-ras: consensus ligand binding sites and other reactive regions from probe-based molecular dynamics analysis. Proteins 2015; 83:898-909. [PMID: 25740554 PMCID: PMC4400267 DOI: 10.1002/prot.24786] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2014] [Revised: 02/16/2015] [Accepted: 02/24/2015] [Indexed: 01/21/2023]
Abstract
We have used probe-based molecular dynamics (pMD) simulations to search for interaction hotspots on the surface of the therapeutically highly relevant oncogenic K-Ras G12D. Combining the probe-based query with an ensemble-based pocket identification scheme and an analysis of existing Ras-ligand complexes, we show that (i) pMD is a robust and cost-effective strategy for binding site identification, (ii) all four of the previously reported ligand binding sites are suitable for structure-based ligand design, and (iii) in some cases probe binding and expanded sampling of configurational space enable pocket expansion and increase the likelihood of site identification. Furthermore, by comparing the distribution of hotspots in nonpocket-like regions with known protein- and membrane-interacting interfaces, we propose that pMD has the potential to predict surface patches responsible for protein-biomolecule interactions. These observations have important implications for future drug design efforts and will facilitate the search for potential interfaces responsible for the proposed transient oligomerization or interaction of Ras with other biomolecules in the cellular milieu.
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Affiliation(s)
- Priyanka Prakash
- University of Texas Health Science Center at Houston, Department of Integrative Biology and Pharmacology, 6431 Fannin St., Houston, Texas 77030
| | - John F. Hancock
- University of Texas Health Science Center at Houston, Department of Integrative Biology and Pharmacology, 6431 Fannin St., Houston, Texas 77030
| | - Alemayehu A. Gorfe
- University of Texas Health Science Center at Houston, Department of Integrative Biology and Pharmacology, 6431 Fannin St., Houston, Texas 77030
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21
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Abstract
Several reports using recently developed physicochemical and imaging techniques have provided experimental evidence for the existence of dimers of Ras proteins, which was first postulated more than 25 years ago. These data have sparked renewed interest in the potential physiological and pathological importance of homo- or heterodimerization of Ras proteins. Understanding the structural and functional properties of Ras dimers should provide mechanistic explanations for unanswered questions regarding the involvement of Ras proteins in signaling pathways that contribute to both normal physiology and oncogenic processes. Furthermore, this knowledge should enable the development of new drugs targeting Ras proteins.
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Affiliation(s)
- Eugenio Santos
- Centro de Investigación del Cáncer, IBMCC (Consejo Superior de Investigaciones Cientificas-Universidad de Salamanca), University of Salamanca, Campus Unamuno, 37007 Salamanca, Spain
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