1
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Lehman SS, Williamson CD, Tucholski T, Ellis NA, Bouchard S, Jarnik M, Allen M, Nita-Lazar A, Machner MP. The Legionella pneumophila effector DenR hijacks the host NRas proto-oncoprotein to downregulate MAPK signaling. Cell Rep 2024; 43:114033. [PMID: 38568811 PMCID: PMC11141579 DOI: 10.1016/j.celrep.2024.114033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Revised: 01/17/2024] [Accepted: 03/18/2024] [Indexed: 04/05/2024] Open
Abstract
Small GTPases of the Ras subfamily are best known for their role as proto-oncoproteins, while their function during microbial infection has remained elusive. Here, we show that Legionella pneumophila hijacks the small GTPase NRas to the Legionella-containing vacuole (LCV) surface. A CRISPR interference screen identifies a single L. pneumophila effector, DenR (Lpg1909), required for this process. Recruitment is specific for NRas, while its homologs KRas and HRas are excluded from LCVs. The C-terminal hypervariable tail of NRas is sufficient for recruitment, and interference with either NRas farnesylation or S-acylation sites abrogates recruitment. Intriguingly, we detect markers of active NRas signaling on the LCV, suggesting it acts as a signaling platform. Subsequent phosphoproteomics analyses show that DenR rewires the host NRas signaling landscape, including dampening of the canonical mitogen-activated protein kinase pathway. These results provide evidence for L. pneumophila targeting NRas and suggest a link between NRas GTPase signaling and microbial infection.
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Affiliation(s)
- Stephanie S Lehman
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Chad D Williamson
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Trisha Tucholski
- Functional Cellular Networks Section, Laboratory of Immune System Biology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Nicole A Ellis
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Sabrina Bouchard
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Michal Jarnik
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Morgan Allen
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Aleksandra Nita-Lazar
- Functional Cellular Networks Section, Laboratory of Immune System Biology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Matthias P Machner
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA.
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2
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García-España A, Philips MR. Origin and Evolution of RAS Membrane Targeting. Oncogene 2023; 42:1741-1750. [PMID: 37031342 PMCID: PMC10413328 DOI: 10.1038/s41388-023-02672-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 03/08/2023] [Accepted: 03/15/2023] [Indexed: 04/10/2023]
Abstract
KRAS, HRAS and NRAS proto-oncogenes belong to a family of 40 highly homologous genes, which in turn are a subset of a superfamily of >160 genes encoding small GTPases. RAS proteins consist of a globular G-domain (aa1-166) and a 22-23 aa unstructured hypervariable region (HVR) that mediates membrane targeting. The evolutionary origins of the RAS isoforms, their HVRs and alternative splicing of the KRAS locus has not been explored. We found that KRAS is basal to the RAS proto-oncogene family and its duplication generated HRAS in the common ancestor of vertebrates. In a second round of duplication HRAS generated NRAS and KRAS generated an additional RAS gene we have designated KRASBL, absent in mammals and birds. KRAS4A arose through a duplication and insertion of the 4th exon of NRAS into the 3rd intron of KRAS. We found evolutionary conservation of a short polybasic region (PBR1) in HRAS, NRAS and KRAS4A, a second polybasic region (PBR2) in KRAS4A, two neutralized basic residues (NB) and a serine in KRAS4B and KRASBL, and a modification of the CaaX motif in vertebrates with farnesyl rather than geranylgeranyl polyisoprene lipids, suggesting that a less hydrophobic membrane anchor is critical to RAS protein function. The persistence of four RAS isoforms through >400 million years of evolution argues strongly for differential function.
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Affiliation(s)
| | - Mark R Philips
- Perlmutter Cancer Center, New York University Grossman School of Medicine, New York, NY, USA.
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3
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García-España A, Philips MR. Origin and evolution of RAS oncoprotein membrane targeting. RESEARCH SQUARE 2023:rs.3.rs-2485219. [PMID: 36711820 PMCID: PMC9882654 DOI: 10.21203/rs.3.rs-2485219/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
KRAS, HRAS and NRAS oncogenes belong to a family of 40 highly homologous genes, which in turn are a subset of a superfamily of >160 genes encoding small GTPases. RAS oncoproteins consist of a globular G-domain (aa1-166) and a 22-23aa unstructured hypervariable region (HVR) that mediates membrane targeting. The evolutionarily origins of the RAS isoforms, their HVRs and alternative splicing of the KRAS locus has not been explored. We found that KRAS is basal to the oncogene family and its duplication generated HRAS in the common ancestor of vertebrates. In a second round of duplication HRAS generated NRAS and KRAS generated an additional RAS gene we have designated KRASBL, absent in mammals and birds. KRAS4A arose through a duplication and insertion of the 4th exon of NRAS into the 3rd intron of KRAS. We found evolutionarily conservation of a short polybasic region (PBR1) in HRAS, NRAS and KRAS4A, a second polybasic region (PBR2) in KRAS4A, two neutralized basic residues (NB) and a serine in KRAS4B and KRASBL, and a modification of the CaaX motif in vertebrates with farnesyl rather than geranylgeranyl polyisoprene lipids, suggesting that a less hydrophobic membrane anchor is critical to RAS oncoprotein function. The persistence of four RAS isoforms through >400 MY of evolution argues strongly for differential function.
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Affiliation(s)
| | - Mark R Philips
- Perlmutter Cancer Center, New York University Grossman School of Medicine, New York, NY, USA
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4
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Campbell SL, Philips MR. Post-translational modification of RAS proteins. Curr Opin Struct Biol 2021; 71:180-192. [PMID: 34365229 DOI: 10.1016/j.sbi.2021.06.015] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Accepted: 06/25/2021] [Indexed: 11/26/2022]
Abstract
Mutations of RAS genes drive cancer more frequently than any other oncogene. RAS proteins integrate signals from a wide array of receptors and initiate downstream signaling through pathways that control cellular growth. RAS proteins are fundamentally binary molecular switches in which the off/on state is determined by the binding of GDP or GTP, respectively. As such, the intrinsic and regulated nucleotide-binding and hydrolytic properties of the RAS GTPase were historically believed to account for the entirety of the regulation of RAS signaling. However, it is increasingly clear that RAS proteins are also regulated by a vast array of post-translational modifications (PTMs). The current challenge is to understand what are the functional consequences of these modifications and which are physiologically relevant. Because PTMs are catalyzed by enzymes that may offer targets for drug discovery, the study of RAS PTMs has been a high priority for RAS biologists.
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Affiliation(s)
| | - Mark R Philips
- Perlmutter Cancer Center, NYU Grossman School of Medicine, USA
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5
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Schmidt-Arras D, Rose-John S. Endosomes as Signaling Platforms for IL-6 Family Cytokine Receptors. Front Cell Dev Biol 2021; 9:688314. [PMID: 34141712 PMCID: PMC8204807 DOI: 10.3389/fcell.2021.688314] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 04/28/2021] [Indexed: 12/12/2022] Open
Abstract
Interleukin-6 (IL-6) is the name-giving cytokine of a family of eleven members, including IL-6, CNTF, LIF, and IL-27. IL-6 was first recognized as a B-cell stimulating factor but we now know that the cytokine plays a pivotal role in the orchestration of inflammatory processes as well as in inflammation associated cancer. Moreover, IL-6 is involved in metabolic regulation and it has been shown to be involved in major neural activities such as neuroprotection, which can help to repair and to reduce brain damage. Receptor complexes of all members formed at the plasma membrane contain one or two molecules of the signaling receptor subunit GP130 and the mechanisms of signal transduction are well understood. IL-6 type cytokines can also signal from endomembranes, in particular the endosome, and situations have been reported in which endocytosis of receptor complexes are a prerequisite of intracellular signaling. Moreover, pathogenic GP130 variants were shown to interfere with spatial activation of downstream signals. We here summarize the molecular mechanisms underlying spatial regulation of IL-6 family cytokine signaling and discuss its relevance for pathogenic processes.
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Affiliation(s)
- Dirk Schmidt-Arras
- Institute of Biochemistry, Christian-Albrechts-University Kiel, Kiel, Germany
| | - Stefan Rose-John
- Institute of Biochemistry, Christian-Albrechts-University Kiel, Kiel, Germany
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6
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Shimell JJ, Shah BS, Cain SM, Thouta S, Kuhlmann N, Tatarnikov I, Jovellar DB, Brigidi GS, Kass J, Milnerwood AJ, Snutch TP, Bamji SX. The X-Linked Intellectual Disability Gene Zdhhc9 Is Essential for Dendrite Outgrowth and Inhibitory Synapse Formation. Cell Rep 2020; 29:2422-2437.e8. [PMID: 31747610 DOI: 10.1016/j.celrep.2019.10.065] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Revised: 09/09/2019] [Accepted: 10/13/2019] [Indexed: 11/29/2022] Open
Abstract
Palmitoylation is a reversible post-translational lipid modification that facilitates vesicular transport and subcellular localization of modified proteins. This process is catalyzed by ZDHHC enzymes that are implicated in several neurological and neurodevelopmental disorders. Loss-of-function mutations in ZDHHC9 have been identified in patients with X-linked intellectual disability (XLID) and associated with increased epilepsy risk. Loss of Zdhhc9 function in hippocampal cultures leads to shorter dendritic arbors and fewer inhibitory synapses, altering the ratio of excitatory-to-inhibitory inputs formed onto Zdhhc9-deficient cells. While Zdhhc9 promotes dendrite outgrowth through the palmitoylation of the GTPase Ras, it promotes inhibitory synapse formation through the palmitoylation of another GTPase, TC10. Zdhhc9 knockout mice exhibit seizure-like activity together with increased frequency and amplitude of both spontaneous and miniature excitatory and inhibitory postsynaptic currents. These findings present a plausible mechanism for how the loss of ZDHHC9 function may contribute to XLID and epilepsy.
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Affiliation(s)
- Jordan J Shimell
- Department of Cellular and Physiological Sciences, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z3, Canada
| | - Bhavin S Shah
- Department of Cellular and Physiological Sciences, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z3, Canada
| | - Stuart M Cain
- Michael Smith Laboratories, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2215 Wesbrook Mall, Vancouver, BC V6T 1Z3, Canada
| | - Samrat Thouta
- Michael Smith Laboratories, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2215 Wesbrook Mall, Vancouver, BC V6T 1Z3, Canada
| | - Naila Kuhlmann
- Montreal Neurological Institute, Department of Neurology and Neurosurgery, McGill University, 3801 University Street, Montreal, QC H3A 2B4, Canada
| | - Igor Tatarnikov
- Montreal Neurological Institute, Department of Neurology and Neurosurgery, McGill University, 3801 University Street, Montreal, QC H3A 2B4, Canada
| | - D Blair Jovellar
- Department of Cellular and Physiological Sciences, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z3, Canada
| | - G Stefano Brigidi
- Department of Cellular and Physiological Sciences, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z3, Canada
| | - Jennifer Kass
- Michael Smith Laboratories, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2215 Wesbrook Mall, Vancouver, BC V6T 1Z3, Canada
| | - Austen J Milnerwood
- Montreal Neurological Institute, Department of Neurology and Neurosurgery, McGill University, 3801 University Street, Montreal, QC H3A 2B4, Canada
| | - Terrance P Snutch
- Michael Smith Laboratories, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2215 Wesbrook Mall, Vancouver, BC V6T 1Z3, Canada
| | - Shernaz X Bamji
- Department of Cellular and Physiological Sciences, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z3, Canada.
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7
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Santra T, Herrero A, Rodriguez J, von Kriegsheim A, Iglesias-Martinez LF, Schwarzl T, Higgins D, Aye TT, Heck AJR, Calvo F, Agudo-Ibáñez L, Crespo P, Matallanas D, Kolch W. An Integrated Global Analysis of Compartmentalized HRAS Signaling. Cell Rep 2020; 26:3100-3115.e7. [PMID: 30865897 DOI: 10.1016/j.celrep.2019.02.038] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Revised: 12/16/2018] [Accepted: 02/11/2019] [Indexed: 12/27/2022] Open
Abstract
Modern omics technologies allow us to obtain global information on different types of biological networks. However, integrating these different types of analyses into a coherent framework for a comprehensive biological interpretation remains challenging. Here, we present a conceptual framework that integrates protein interaction, phosphoproteomics, and transcriptomics data. Applying this method to analyze HRAS signaling from different subcellular compartments shows that spatially defined networks contribute specific functions to HRAS signaling. Changes in HRAS protein interactions at different sites lead to different kinase activation patterns that differentially regulate gene transcription. HRAS-mediated signaling is the strongest from the cell membrane, but it regulates the largest number of genes from the endoplasmic reticulum. The integrated networks provide a topologically and functionally resolved view of HRAS signaling. They reveal distinct HRAS functions including the control of cell migration from the endoplasmic reticulum and TP53-dependent cell survival when signaling from the Golgi apparatus.
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Affiliation(s)
- Tapesh Santra
- Systems Biology Ireland, University College Dublin, Belfield, Dublin, Ireland
| | - Ana Herrero
- Systems Biology Ireland, University College Dublin, Belfield, Dublin, Ireland
| | - Javier Rodriguez
- Systems Biology Ireland, University College Dublin, Belfield, Dublin, Ireland
| | - Alex von Kriegsheim
- Systems Biology Ireland, University College Dublin, Belfield, Dublin, Ireland
| | | | - Thomas Schwarzl
- Systems Biology Ireland, University College Dublin, Belfield, Dublin, Ireland
| | - Des Higgins
- Systems Biology Ireland, University College Dublin, Belfield, Dublin, Ireland; Conway Institute of Biomolecular & Biomedical Research, University College Dublin, Belfield, Ireland; School of Medicine and Medical Science, University College Dublin, Belfield, Ireland
| | - Thin-Thin Aye
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Centre for Biomolecular Research and Utrecht Institute for Pharmaceutical Science, Utrecht University, Padualaan 8, 3584 Utrecht, the Netherlands
| | - Albert J R Heck
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Centre for Biomolecular Research and Utrecht Institute for Pharmaceutical Science, Utrecht University, Padualaan 8, 3584 Utrecht, the Netherlands
| | - Fernando Calvo
- Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Consejo Superior de Investigaciones Científicas (CSIC) - Universidad de Cantabria, Santander 39011, Spain
| | - Lorena Agudo-Ibáñez
- Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Consejo Superior de Investigaciones Científicas (CSIC) - Universidad de Cantabria, Santander 39011, Spain
| | - Piero Crespo
- Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Consejo Superior de Investigaciones Científicas (CSIC) - Universidad de Cantabria, Santander 39011, Spain; Centro de Investigación Biomédica en Red de Cáncer (CIBERONC), Instituto de Salud Carlos III, Madrid, Spain
| | - David Matallanas
- Systems Biology Ireland, University College Dublin, Belfield, Dublin, Ireland.
| | - Walter Kolch
- Systems Biology Ireland, University College Dublin, Belfield, Dublin, Ireland; Conway Institute of Biomolecular & Biomedical Research, University College Dublin, Belfield, Ireland; School of Medicine and Medical Science, University College Dublin, Belfield, Ireland.
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8
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Abstract
The most frequently mutated oncogene in cancer is KRAS, which utilizes alternative fourth exons to generate two gene products, KRAS4A and KRAS4B, that differ only in their C-terminal membrane-targeting region 1. Because oncogenic mutations occur in exons 2 or 3, when KRAS is activated by mutation two constitutively active KRAS proteins are encoded, each capable of transforming cells 2. No functional distinctions among the splice variants have been established. Oncogenic KRAS alters tumor metabolism 3. Among these alterations is increased glucose uptake and glycolysis, even in the presence of abundant oxygen 4 (the Warburg Effect). Whereas these metabolic effects of oncogenic KRAS have been explained by transcriptional upregulation of glucose transporters and glycolytic enzymes 3–5, direct regulation of metabolic enzymes has not been examined. We report a direct, GTP-dependent interaction between KRAS4A and hexokinase 1 (HK1) that alters the activity of the kinase, establishing HK1 as an effector of KRAS4A. The interaction is unique to KRAS4A because the palmitoylation/depalmitoylation cycle of this RAS isoform permits co-localization with HK1 on the outer mitochondrial membrane (OMM). KRAS4A expression in cancer may drive unique metabolic vulnerabilities that can be exploited therapeutically.
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9
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Abstract
The three RAS genes - HRAS, NRAS and KRAS - are collectively mutated in one-third of human cancers, where they act as prototypic oncogenes. Interestingly, there are rather distinct patterns to RAS mutations; the isoform mutated as well as the position and type of substitution vary between different cancers. As RAS genes are among the earliest, if not the first, genes mutated in a variety of cancers, understanding how these mutation patterns arise could inform on not only how cancer begins but also the factors influencing this event, which has implications for cancer prevention. To this end, we suggest that there is a narrow window or 'sweet spot' by which oncogenic RAS signalling can promote tumour initiation in normal cells. As a consequence, RAS mutation patterns in each normal cell are a product of the specific RAS isoform mutated, as well as the position of the mutation and type of substitution to achieve an ideal level of signalling.
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Affiliation(s)
- Siqi Li
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC, USA
| | - Allan Balmain
- Helen Diller Family Comprehensive Cancer Center and Department of Biochemistry and Biophysics, University of California, San Francisco, CA, USA
| | - Christopher M Counter
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC, USA.
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10
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Stehbens SJ, Ju RJ, Adams MN, Perry SR, Haass NK, Bryant DM, Pollock PM. FGFR2-activating mutations disrupt cell polarity to potentiate migration and invasion in endometrial cancer cell models. J Cell Sci 2018; 131:jcs.213678. [PMID: 30002137 DOI: 10.1242/jcs.213678] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Accepted: 06/24/2018] [Indexed: 12/16/2022] Open
Abstract
Fibroblast growth factor receptors (FGFRs) are a family of receptor tyrosine kinases that control a diverse range of biological processes during development and in adult tissues. We recently reported that somatic FGFR2 mutations are associated with shorter survival in endometrial cancer. However, little is known about how these FGFR2 mutations contribute to endometrial cancer metastasis. Here, we report that expression of the activating mutations FGFR2N550K and FGFR2Y376C in an endometrial cancer cell model induce Golgi fragmentation, and loss of polarity and directional migration. In mutant FGFR2-expressing cells, this was associated with an inability to polarise intracellular pools of FGFR2 towards the front of migrating cells. Such polarization defects were exacerbated in three-dimensional culture, where FGFR2 mutant cells were unable to form well-organised acini, instead undergoing exogenous ligand-independent invasion. Our findings uncover collective cell polarity and invasion as common targets of disease-associated FGFR2 mutations that lead to poor outcome in endometrial cancer patients.
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Affiliation(s)
- Samantha J Stehbens
- School of Biomedical Sciences, Queensland University of Technology (QUT) located at the Translational Research Institute, Woolloongabba, Brisbane, QLD 4102, Australia .,The University of Queensland Diamantina Institute, Faculty of Medicine, The University of Queensland, Translational Research Institute, Woolloongabba, Brisbane, QLD 4102, Australia
| | - Robert J Ju
- School of Biomedical Sciences, Queensland University of Technology (QUT) located at the Translational Research Institute, Woolloongabba, Brisbane, QLD 4102, Australia.,The University of Queensland Diamantina Institute, Faculty of Medicine, The University of Queensland, Translational Research Institute, Woolloongabba, Brisbane, QLD 4102, Australia
| | - Mark N Adams
- School of Biomedical Sciences, Queensland University of Technology (QUT) located at the Translational Research Institute, Woolloongabba, Brisbane, QLD 4102, Australia
| | - Samuel R Perry
- School of Biomedical Sciences, Queensland University of Technology (QUT) located at the Translational Research Institute, Woolloongabba, Brisbane, QLD 4102, Australia
| | - Nikolas K Haass
- The University of Queensland Diamantina Institute, Faculty of Medicine, The University of Queensland, Translational Research Institute, Woolloongabba, Brisbane, QLD 4102, Australia
| | - David M Bryant
- Cancer Research UK Beatson Institute, Glasgow, G61 1BD, UK.,Institute of Cancer Sciences, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Pamela M Pollock
- School of Biomedical Sciences, Queensland University of Technology (QUT) located at the Translational Research Institute, Woolloongabba, Brisbane, QLD 4102, Australia
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11
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Herrero A, Reis-Cardoso M, Jiménez-Gómez I, Doherty C, Agudo-Ibañez L, Pinto A, Calvo F, Kolch W, Crespo P, Matallanas D. Characterisation of HRas local signal transduction networks using engineered site-specific exchange factors. Small GTPases 2018; 11:371-383. [PMID: 29172991 DOI: 10.1080/21541248.2017.1406434] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Ras GTPases convey signals from different types of membranes. At these locations, different Ras isoforms, interactors and regulators generate different biochemical signals and biological outputs. The study of Ras localisation-specific signal transduction networks has been hampered by our inability to specifically activate each of these Ras pools. Here, we describe a new set of site-specific tethered exchange factors, engineered by fusing the RasGRF1 CDC25 domain to sub-localisation-defining cues, whereby Ras pools at specific locations can be precisely activated. We show that the CDC25 domain has a high specificity for activating HRas but not NRas and KRas. This unexpected finding means that our constructs mainly activate endogenous HRas. Hence, their use enabled us to identify distinct pathways regulated by HRas in endomembranes and plasma membrane microdomains. Importantly, these new constructs unveil different patterns of HRas activity specified by their subcellular localisation. Overall, the targeted GEFs described herein constitute ideal tools for dissecting spatially-defined HRas biochemical and biological functions.
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Affiliation(s)
- Ana Herrero
- Systems Biology Ireland, University College Dublin , Dublin, Ireland.,School of Medicine and Medical Science, University College Dublin , Dublin, Ireland
| | | | - Iñaki Jiménez-Gómez
- Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Consejo Superior de Investigaciones Científicas (CSIC) - Universidad de Cantabria, Santander , Spain
| | - Carolanne Doherty
- Systems Biology Ireland, University College Dublin , Dublin, Ireland.,School of Medicine and Medical Science, University College Dublin , Dublin, Ireland
| | - Lorena Agudo-Ibañez
- Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Consejo Superior de Investigaciones Científicas (CSIC) - Universidad de Cantabria, Santander , Spain
| | - Adán Pinto
- Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Consejo Superior de Investigaciones Científicas (CSIC) - Universidad de Cantabria, Santander , Spain
| | - Fernando Calvo
- Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Consejo Superior de Investigaciones Científicas (CSIC) - Universidad de Cantabria, Santander , Spain
| | - Walter Kolch
- Systems Biology Ireland, University College Dublin , Dublin, Ireland.,Conway Institute, University College Dublin , Dublin, Ireland.,School of Medicine and Medical Science, University College Dublin , Dublin, Ireland
| | - Piero Crespo
- Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Consejo Superior de Investigaciones Científicas (CSIC) - Universidad de Cantabria, Santander , Spain.,Centro de Investigación Biomédica en Red CIBERONC, Instituto de Salud Calos III , Madrid, Spain
| | - David Matallanas
- Systems Biology Ireland, University College Dublin , Dublin, Ireland.,School of Medicine and Medical Science, University College Dublin , Dublin, Ireland
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12
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Tebar F, Enrich C, Rentero C, Grewal T. GTPases Rac1 and Ras Signaling from Endosomes. PROGRESS IN MOLECULAR AND SUBCELLULAR BIOLOGY 2018; 57:65-105. [PMID: 30097772 DOI: 10.1007/978-3-319-96704-2_3] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The endocytic compartment is not only the functional continuity of the plasma membrane but consists of a diverse collection of intracellular heterogeneous complex structures that transport, amplify, sustain, and/or sort signaling molecules. Over the years, it has become evident that early, late, and recycling endosomes represent an interconnected vesicular-tubular network able to form signaling platforms that dynamically and efficiently translate extracellular signals into biological outcome. Cell activation, differentiation, migration, death, and survival are some of the endpoints of endosomal signaling. Hence, to understand the role of the endosomal system in signal transduction in space and time, it is therefore necessary to dissect and identify the plethora of decoders that are operational in the different steps along the endocytic pathway. In this chapter, we focus on the regulation of spatiotemporal signaling in cells, considering endosomes as central platforms, in which several small GTPases proteins of the Ras superfamily, in particular Ras and Rac1, actively participate to control cellular processes like proliferation and cell mobility.
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Affiliation(s)
- Francesc Tebar
- Departament de Biomedicina, Unitat de Biologia Cel·lular, Facultat de Medicina i Ciències de la Salut, Centre de Recerca Biomèdica CELLEX, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Universitat de Barcelona, Casanova 143, 08036, Barcelona, Spain.
| | - Carlos Enrich
- Departament de Biomedicina, Unitat de Biologia Cel·lular, Facultat de Medicina i Ciències de la Salut, Centre de Recerca Biomèdica CELLEX, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Universitat de Barcelona, Casanova 143, 08036, Barcelona, Spain
| | - Carles Rentero
- Departament de Biomedicina, Unitat de Biologia Cel·lular, Facultat de Medicina i Ciències de la Salut, Centre de Recerca Biomèdica CELLEX, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Universitat de Barcelona, Casanova 143, 08036, Barcelona, Spain
| | - Thomas Grewal
- School of Pharmacy, Faculty of Medicine and Health, University of Sydney, Sydney, NSW, 2006, Australia
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Wan X, Liu R, Li Z. The Prognostic Value of HRAS mRNA Expression in Cutaneous Melanoma. BIOMED RESEARCH INTERNATIONAL 2017; 2017:5356737. [PMID: 29349077 PMCID: PMC5733767 DOI: 10.1155/2017/5356737] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Revised: 10/01/2017] [Accepted: 10/30/2017] [Indexed: 12/15/2022]
Abstract
This study aimed to investigate the prognostic value of HRAS mRNA expression in cutaneous melanoma. Cutaneous melanoma is an aggressive cancer with an increasing incidence. Few studies have focused on the transcriptional level of RAS isoforms (KRAS, NRAS, and HRAS) in cutaneous melanoma. To gain further insight into RAS isoforms at transcriptional level, we obtained the cutaneous melanoma data from cBioPortal and investigated the RAS mRNA expression levels in different stages of melanoma and evaluated their correlation with clinical characteristics and patients' survival. Furthermore, we retrieved and analyzed the coexpression data and performed pathway enrichment analysis. Totally, 452 cutaneous melanoma cases were included in this study. We found that lower HRAS expression level was associated with longer patient survival. 206 genes that negatively correlated with HRAS expression were positively correlated with KRAS and NRAS expression. In contrast, no gene that positively correlated with HRAS expression was positively correlated with KRAS and NRAS expression. In conclusion, our data showed that transcriptional regulation was different for the three RAS isoforms in cutaneous melanoma. This study highlighted the prognostic value of HRAS mRNA expression and revealed that HRAS greatly differs from KRAS and NRAS at the transcriptional level.
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Affiliation(s)
- Xiaohua Wan
- Department of Clinical Laboratory, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, China
| | - Ruping Liu
- Beijing Institute of Graphic Communication, Beijing 102600, China
| | - Zhongwu Li
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Pathology, Peking University Cancer Hospital & Institute, Beijing 100142, China
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Chen GA, Lin YR, Chung HT, Hwang LH. H-Ras Exerts Opposing Effects on Type I Interferon Responses Depending on Its Activation Status. Front Immunol 2017; 8:972. [PMID: 28848563 PMCID: PMC5554495 DOI: 10.3389/fimmu.2017.00972] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Accepted: 07/31/2017] [Indexed: 12/25/2022] Open
Abstract
Using shRNA high-throughput screening, we identified H-Ras as a regulator of antiviral activity, whose depletion could enhance Sindbis virus replication. Further analyses indicated that depletion of H-Ras results in a robust increase in vesicular stomatitis virus infection and a decrease in Sendai virus (SeV)-induced retinoic acid-inducible gene-I-like receptor (RLR) signaling. Interestingly, however, ectopic expression of wild-type H-Ras results in a biphasic mode of RLR signaling regulation: while low-level expression of H-Ras enhances SeV-induced RLR signaling, high-level expression of H-Ras significantly inhibits this signaling. The inhibitory effects correlate with the activation status of H-Ras. As a result, oncogenic H-Ras, H-RasV12, strongly inhibits SeV-induced IFN-β promoter activity and type I interferon signaling. Conversely, the positive effects exerted by H-Ras on RLR signaling are independent of its signaling activity, as a constitutively inactive form of H-Ras, H-RasN17, also positively regulates RLR signaling. Mechanistically, we demonstrate that depletion of H-Ras reduces the formation of MAVS–TNF receptor-associated factor 3 signaling complexes. These results reveal that the H-Ras protein plays a role in promoting MAVS signalosome assembly in the mitochondria, whereas oncogenic H-Ras exerts a negative effect on type I IFN responses.
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Affiliation(s)
- Guann-An Chen
- Institute of Microbiology and Immunology, National Yang-Ming University, Taipei, Taiwan
| | - Yun-Ru Lin
- Institute of Microbiology and Immunology, National Yang-Ming University, Taipei, Taiwan
| | - Hai-Ting Chung
- Institute of Microbiology and Immunology, National Yang-Ming University, Taipei, Taiwan
| | - Lih-Hwa Hwang
- Institute of Microbiology and Immunology, National Yang-Ming University, Taipei, Taiwan
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15
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Protein S-palmitoylation in cellular differentiation. Biochem Soc Trans 2017; 45:275-285. [PMID: 28202682 PMCID: PMC5310721 DOI: 10.1042/bst20160236] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Revised: 12/15/2016] [Accepted: 12/20/2016] [Indexed: 01/01/2023]
Abstract
Reversible protein S-palmitoylation confers spatiotemporal control of protein function by modulating protein stability, trafficking and activity, as well as protein-protein and membrane-protein associations. Enabled by technological advances, global studies revealed S-palmitoylation to be an important and pervasive posttranslational modification in eukaryotes with the potential to coordinate diverse biological processes as cells transition from one state to another. Here, we review the strategies and tools to analyze in vivo protein palmitoylation and interrogate the functions of the enzymes that put on and take off palmitate from proteins. We also highlight palmitoyl proteins and palmitoylation-related enzymes that are associated with cellular differentiation and/or tissue development in yeasts, protozoa, mammals, plants and other model eukaryotes.
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Makowski SL, Tran TT, Field SJ. Emerging themes of regulation at the Golgi. Curr Opin Cell Biol 2017; 45:17-23. [PMID: 28213314 DOI: 10.1016/j.ceb.2017.01.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Accepted: 01/24/2017] [Indexed: 02/06/2023]
Abstract
The Golgi is generally recognized for its central role in the secretory pathway to orchestrate protein post-translational modification and trafficking of proteins and lipids to their final destination. Despite the common view of the Golgi as an inert sorting organelle, emerging data demonstrate that important signaling events occur at the Golgi, including those that regulate the trafficking function of the Golgi. The phosphatidylinositol-4-phosphate/GOLPH3/MYO18A/F-actin complex serves as a hub for signals that regulate Golgi trafficking function. Furthermore, the Golgi is increasingly appreciated for its important role in cell growth and in driving oncogenic transformation, as illuminated by the discovery that GOLPH3 and MYO18A are cancer drivers.
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Affiliation(s)
- Stefanie L Makowski
- Department of Medicine, Division of Endocrinology and Metabolism, University of California, San Diego, CA 92093-0707, USA
| | - Thuy Tt Tran
- Department of Medicine, Division of Endocrinology and Metabolism, University of California, San Diego, CA 92093-0707, USA
| | - Seth J Field
- Department of Medicine, Division of Endocrinology and Metabolism, University of California, San Diego, CA 92093-0707, USA.
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Patra S, Erwin N, Winter R. Translational Dynamics of Lipidated Ras Proteins in the Presence of Crowding Agents and Compatible Osmolytes. Chemphyschem 2016; 17:2164-9. [PMID: 27028423 DOI: 10.1002/cphc.201600179] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Indexed: 11/07/2022]
Abstract
Ras proteins are small GTPases and are involved in transmitting signals that control cell growth, differentiation, and proliferation. Since the cell cytoplasm is crowded with different macromolecules, understanding the translational dynamics of Ras proteins in crowded environments is crucial to yielding deeper insight into their reactivity and function. Herein, the translational dynamics of lipidated N-Ras and K-Ras4B is studied in the bulk and in the presence of a macromolecular crowder (Ficoll) and the compatible osmolyte and microcrowder sucrose by fluorescence correlation spectroscopy. The results reveal that N-Ras forms dimers due to the presence of its lipid moiety in the hypervariable region, whereas K-Ras4B remains in its monomeric form in the bulk. Addition of a macromolecular crowding agent gradually favors clustering of the Ras proteins. In 20 wt % Ficoll N-Ras forms trimers and K-Ras4B dimers. Concentrations of sucrose up to 10 wt % foster formation of N-Ras trimers and K-Ras dimers as well. The results can be rationalized in terms of the excluded-volume effect, which enhances the association of the proteins, and, for the higher concentrations, by limited-hydration conditions. The results of this study shed new light on the association state of these proteins in a crowded environment. This is of particular interest for the Ras proteins, because their solution state-monomeric or clustered-influences their membrane-partitioning behavior and their interplay with cytosolic interaction partners.
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Affiliation(s)
- Satyajit Patra
- Department of Chemistry and Chemical Biology, Biophysical Chemistry, TU Dortmund University, Otto-Hahn-Strasse 4a, 44227, Dortmund, Germany
| | - Nelli Erwin
- Department of Chemistry and Chemical Biology, Biophysical Chemistry, TU Dortmund University, Otto-Hahn-Strasse 4a, 44227, Dortmund, Germany
| | - Roland Winter
- Department of Chemistry and Chemical Biology, Biophysical Chemistry, TU Dortmund University, Otto-Hahn-Strasse 4a, 44227, Dortmund, Germany.
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Chakrabarti M, Jang H, Nussinov R. Comparison of the Conformations of KRAS Isoforms, K-Ras4A and K-Ras4B, Points to Similarities and Significant Differences. J Phys Chem B 2016; 120:667-79. [PMID: 26761128 PMCID: PMC7815164 DOI: 10.1021/acs.jpcb.5b11110] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Human HRAS, KRAS, and NRAS genes encode four isoforms of Ras, a p21 GTPase. Mutations in KRAS account for the majority of RAS-driven cancers. The KRAS has two splice variants, K-Ras4A and K-Ras4B. Due to their reversible palmitoylation, K-Ras4A and N-Ras have bimodal signaling states. K-Ras4A and K-Ras4B differ in four catalytic domain residues (G151R/D153E/K165Q/H166Y) and in their disordered C-terminal hypervariable region (HVR). In K-Ras4A, the HVR is not as strongly positively charged as in K-Ras4B (+6e vs +9e). Here, we performed all-atom molecular dynamics simulations to elucidate isoform-specific differences between the two splice variants. We observe that the catalytic domain of GDP-bound K-Ras4A has a more exposed nucleotide binding pocket than K-Ras4B, and the dynamic fluctuations in switch I and II regions also differ; both factors may influence guanine-nucleotide exchange. We further observe that like K-Kas4B, full-length K-Ras4A exhibits nucleotide-dependent HVR fluctuations; however, these fluctuations differ between the GDP-bound forms of K-Ras4A and K-Ras4B. Unlike K-Ras4B where the HVR tends to cover the effector binding region, in K-Ras4A, autoinhibited states are unstable. With lesser charge, the K-Ras4A HVR collapses on itself, making it less available for binding the catalytic domain. Since the HVRs of N- and H-Ras are weakly charged (+1e and +2e, respectively), autoinhibition may be a unique feature of K-Ras4B.
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Affiliation(s)
- Mayukh Chakrabarti
- Cancer and Inflammation Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, National Cancer Institute at Frederick, Frederick, Maryland 21702, United States
| | - Hyunbum Jang
- Cancer and Inflammation Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, National Cancer Institute at Frederick, Frederick, Maryland 21702, United States
| | - Ruth Nussinov
- Cancer and Inflammation Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, National Cancer Institute at Frederick, Frederick, Maryland 21702, United States
- Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
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Hernandez-Valladares M, Prior IA. Comparative proteomic analysis of compartmentalised Ras signalling. Sci Rep 2015; 5:17307. [PMID: 26620772 PMCID: PMC4664896 DOI: 10.1038/srep17307] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Accepted: 10/28/2015] [Indexed: 12/27/2022] Open
Abstract
Ras proteins are membrane bound signalling hubs that operate from both the cell surface and endomembrane compartments. However, the extent to which intracellular pools of Ras can contribute to cell signalling is debated. To address this, we have performed a global screen of compartmentalised Ras signalling. We find that whilst ER/Golgi- and endosomal-Ras only generate weak outputs, Ras localised to the mitochondria or Golgi significantly and distinctly influence both the abundance and phosphorylation of a wide range of proteins analysed. Our data reveal that ~80% of phosphosites exhibiting large (≥1.5-fold) changes compared to control can be modulated by organellar Ras signalling. The majority of compartmentalised Ras-specific responses are predicted to influence gene expression, RNA splicing and cell proliferation. Our analysis reinforces the concept that compartmentalisation influences Ras signalling and provides detailed insight into the widespread modulation of responses downstream of endomembranous Ras signalling.
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Affiliation(s)
- Maria Hernandez-Valladares
- Physiological Laboratory, Institute of Translational Medicine, University of Liverpool, Crown Street, Liverpool L69 3BX, United Kingdom
| | - Ian A Prior
- Physiological Laboratory, Institute of Translational Medicine, University of Liverpool, Crown Street, Liverpool L69 3BX, United Kingdom
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20
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Prakash P, Sayyed-Ahmad A, Gorfe AA. pMD-Membrane: A Method for Ligand Binding Site Identification in Membrane-Bound Proteins. PLoS Comput Biol 2015; 11:e1004469. [PMID: 26506102 PMCID: PMC4623977 DOI: 10.1371/journal.pcbi.1004469] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2015] [Accepted: 07/27/2015] [Indexed: 12/22/2022] Open
Abstract
Probe-based or mixed solvent molecular dynamics simulation is a useful approach for the identification and characterization of druggable sites in drug targets. However, thus far the method has been applied only to soluble proteins. A major reason for this is the potential effect of the probe molecules on membrane structure. We have developed a technique to overcome this limitation that entails modification of force field parameters to reduce a few pairwise non-bonded interactions between selected atoms of the probe molecules and bilayer lipids. We used the resulting technique, termed pMD-membrane, to identify allosteric ligand binding sites on the G12D and G13D oncogenic mutants of the K-Ras protein bound to a negatively charged lipid bilayer. In addition, we show that differences in probe occupancy can be used to quantify changes in the accessibility of druggable sites due to conformational changes induced by membrane binding or mutation.
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Affiliation(s)
- Priyanka Prakash
- University of Texas Health Science Center at Houston, Department of Integrative Biology and Pharmacology, Houston, Texas, United States of America
| | - Abdallah Sayyed-Ahmad
- University of Texas Health Science Center at Houston, Department of Integrative Biology and Pharmacology, Houston, Texas, United States of America
| | - Alemayehu A. Gorfe
- University of Texas Health Science Center at Houston, Department of Integrative Biology and Pharmacology, Houston, Texas, United States of America
- * E-mail:
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21
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Abstract
RAS proteins are key signalling hubs that are oncogenically mutated in 30% of all cancer cases. Three genes encode almost identical isoforms that are ubiquitously expressed, but are not functionally redundant. The network responses associated with each isoform and individual oncogenic mutations remain to be fully characterized. In the present article, we review recent data defining the differences between the RAS isoforms and their most commonly mutated codons and discuss the underlying mechanisms.
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22
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Gil Ferreira C, Aran V, Zalcberg-Renault I, Victorino AP, Salem JH, Bonamino MH, Vieira FM, Zalis M. KRAS mutations: variable incidences in a Brazilian cohort of 8,234 metastatic colorectal cancer patients. BMC Gastroenterol 2014; 14:73. [PMID: 24720724 PMCID: PMC3997472 DOI: 10.1186/1471-230x-14-73] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2013] [Accepted: 04/02/2014] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND KRAS mutations are frequently found in colorectal cancer (CRC) indicating the importance of its genotyping in the study of the molecular mechanisms behind this disease. Although major advances have occurred over the past decade, there are still important gaps in our understanding of CRC carcinogenesis, particularly whether sex-linked factors play any role. METHODS The profile of KRAS mutations in the Brazilian population was analyzed by conducting direct sequencing of KRAS codons 12 and 13 belonging to 8,234 metastatic CRC patient samples. DNA was extracted from paraffin-embedded tissue, exon 1 was amplified by PCR and submitted to direct sequencing. The data obtained was analysed comparing different geographical regions, gender and age. RESULTS The median age was 59 years and the overall percentage of wild-type and mutated KRAS was 62.8% and 31.9%, respectively. Interestingly, different percentages of mutated KRAS patients were observed between male and female patients (32.5% versus 34.8%, respectively; p = 0.03). KRAS Gly12Asp mutation was the most prevalent for both genders and for most regions, with the exception of the North where Gly12Val was the most frequent mutation found. CONCLUSIONS To the best of our knowledge this is one of the largest cohorts of KRAS genotyping in CRC patients and the largest to indicate a higher incidence of KRAS mutation in females compared to males in Brazil. Nevertheless, further research is required to better address the impact of gender differences in colorectal cancer.
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Affiliation(s)
- Carlos Gil Ferreira
- Progenética Diagnósticos Moleculares, Av, Presidente Vargas, 962 3 Andar, Cep: 20071-002 Rio de Janeiro, RJ, Brazil.
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Prakash P, Gorfe AA. Lessons from computer simulations of Ras proteins in solution and in membrane. Biochim Biophys Acta Gen Subj 2013; 1830:5211-8. [PMID: 23906604 DOI: 10.1016/j.bbagen.2013.07.024] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2013] [Revised: 07/23/2013] [Accepted: 07/24/2013] [Indexed: 12/22/2022]
Abstract
BACKGROUND A great deal has been learned over the last several decades about the function of Ras proteins in solution and membrane environments. While much of this knowledge has been derived from a plethora of experimental techniques, computer simulations have also played a substantial role. SCOPE OF REVIEW Our goal here is to summarize the contribution of molecular simulations to our current understanding of normal and aberrant Ras function. We focus on lessons from molecular dynamics simulations in aqueous and membrane environments. MAJOR CONCLUSIONS The central message is that a close interaction between theory and simulation on the one hand and cell-biological, spectroscopic and other experimental approaches on the other has played, and will likely continue to play, a vital role in Ras research. GENERAL SIGNIFICANCE Atomistic insights emerging from detailed simulations of Ras in solution and in bilayers may be the key to unlock the secret that to date prevented development of selective anti-Ras inhibitors for cancer therapy.
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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, TX 77030, USA
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