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Mutation Analysis of Braf Exon 15 and Kras Codons 12 and 13 in Moroccan Patients with Colorectal Cancer. Int J Biol Markers 2018. [DOI: 10.5301/jbm.2010.6091] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Background The RAS/RAF/MEK/MAP kinase cascade transduces signals from the cell surface to the nucleus in order to control cellular responses including proliferation, differentiation and survival. We investigated the occurrence of BRAF exon 15 and KRAS codon 12 and 13 mutations in Moroccan patients with colorectal cancer. Methods Sixty-two samples from patients with sporadic colorectal adenocarcinomas were studied for BRAF exon 15 and KRAS codon 12 and 13 mutations. DNA from paraffin-embedded tissue specimens was analyzed by a combination of polymerase chain reaction–high resolution melting and direct sequencing. Results Of the analyzed specimens, 29% exhibited KRAS codon 12 or 13 mutations and only 1.6% carried a BRAF codon 600 mutation. KRAS mutations were more often observed in women (35.5%) than in men (22.6%). Patients in the age range between 41 and 60 years were more likely to be carriers of this mutation. No KRAS mutations were detected in patients aged >60 years. Conclusion Despite the limited study sample, our data suggest that KRAS mutations arise more frequently than BRAF mutations in Moroccan patients with colorectal carcinomas. The KRAS mutation status must be assessed in a large cohort of Moroccan patients to confirm these findings and to determine whether this mutation in combination with extrinsic, environmental or microenvironmental factors might be involved in the high frequency of colorectal cancer in middle-aged Moroccans.
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Manevitz-Mendelson E, Leichner GS, Barel O, Davidi-Avrahami I, Ziv-Strasser L, Eyal E, Pessach I, Rimon U, Barzilai A, Hirshberg A, Chechekes K, Amariglio N, Rechavi G, Yaniv K, Greenberger S. Somatic NRAS mutation in patient with generalized lymphatic anomaly. Angiogenesis 2018; 21:287-298. [PMID: 29397482 DOI: 10.1007/s10456-018-9595-8] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Accepted: 01/04/2018] [Indexed: 12/28/2022]
Abstract
Generalized lymphatic anomaly (GLA or lymphangiomatosis) is a rare disease characterized by a diffuse proliferation of lymphatic vessels in skin and internal organs. It often leads to progressive respiratory failure and death, but its etiology is unknown. Here, we isolated lymphangiomatosis endothelial cells from GLA tissue. These cells were characterized by high proliferation and survival rates, but displayed impaired capacities for migration and tube formation. We employed whole exome sequencing to search for disease-causing genes and identified a somatic mutation in NRAS. We used mouse and zebrafish model systems to initially evaluate the role of this mutation in the development of the lymphatic system, and we studied the effect of drugs blocking the downstream effectors, mTOR and ERK, on this disease.
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Affiliation(s)
| | - Gil S Leichner
- Department of Dermatology, Sheba Medical Center, Tel Hashomer, Ramat Gan, Israel
| | - Ortal Barel
- Sheba Cancer Research Center, Sheba Medical Center, Tel Hashomer, Ramat Gan, Israel
| | | | - Limor Ziv-Strasser
- Sheba Cancer Research Center, Sheba Medical Center, Tel Hashomer, Ramat Gan, Israel
| | - Eran Eyal
- Sheba Cancer Research Center, Sheba Medical Center, Tel Hashomer, Ramat Gan, Israel
| | - Itai Pessach
- Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
- Department of Pediatric Critical Care, Safra Children's Hospital, Sheba Medical Center, Tel Hashomer, Ramat Gan, Israel
| | - Uri Rimon
- Department of Radiology, Sheba Medical Center, Tel Hashomer, Ramat Gan, Israel
| | - Aviv Barzilai
- Department of Dermatology, Sheba Medical Center, Tel Hashomer, Ramat Gan, Israel
- Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Abraham Hirshberg
- Department of Oral Pathology and Oral Medicine, School of Dental Medicine, Tel-Aviv University, Tel Aviv, Israel
| | - Keren Chechekes
- Sheba Cancer Research Center, Sheba Medical Center, Tel Hashomer, Ramat Gan, Israel
| | - Ninette Amariglio
- Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
- Sheba Cancer Research Center, Sheba Medical Center, Tel Hashomer, Ramat Gan, Israel
| | - Gideon Rechavi
- Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
- Sheba Cancer Research Center, Sheba Medical Center, Tel Hashomer, Ramat Gan, Israel
| | - Karina Yaniv
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel
| | - Shoshana Greenberger
- Department of Dermatology, Sheba Medical Center, Tel Hashomer, Ramat Gan, Israel.
- Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.
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53
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Watson U, Jain R, Asthana S, Saini DK. Spatiotemporal Modulation of ERK Activation by GPCRs. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2018; 338:111-140. [DOI: 10.1016/bs.ircmb.2018.02.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
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54
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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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55
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Basu SK, Lee S, Salotti J, Basu S, Sakchaisri K, Xiao Z, Walia V, Westlake CJ, Morrison DK, Johnson PF. Oncogenic RAS-Induced Perinuclear Signaling Complexes Requiring KSR1 Regulate Signal Transmission to Downstream Targets. Cancer Res 2017; 78:891-908. [PMID: 29259016 DOI: 10.1158/0008-5472.can-17-2353] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Revised: 10/27/2017] [Accepted: 12/12/2017] [Indexed: 12/31/2022]
Abstract
The precise characteristics that distinguish normal and oncogenic RAS signaling remain obscure. Here, we show that oncogenic RAS and BRAF induce perinuclear relocalization of several RAS pathway proteins, including the kinases CK2 and p-ERK1/2 and the signaling scaffold KSR1. This spatial reorganization requires endocytosis, the kinase activities of MEK-ERK and CK2, and the presence of KSR1. CK2α colocalizes with KSR1 and Rab11, a marker of recycling endosomes, whereas p-ERK associates predominantly with a distinct KSR1-positive endosomal population. Notably, these perinuclear signaling complexes (PSC) are present in tumor cell lines, mouse lung tumors, and mouse embryonic fibroblasts undergoing RAS-induced senescence. PSCs are also transiently induced by growth factors (GF) in nontransformed cells with delayed kinetics (4-6 hours), establishing a novel late phase of GF signaling that appears to be constitutively activated in tumor cells. PSCs provide an essential platform for RAS-induced phosphorylation and activation of the prosenescence transcription factor C/EBPβ in primary MEFs undergoing senescence. Conversely, in tumor cells, C/EBPβ activation is suppressed by 3'UTR-mediated localization of Cebpb transcripts to a peripheral cytoplasmic domain distinct from the PSC region. Collectively, our findings indicate that sustained PSC formation is a critical feature of oncogenic RAS/BRAF signaling in cancer cells that controls signal transmission to downstream targets by regulating selective access of effector kinases to substrates such as C/EBPβ.Significance: In addressing the long-standing question of the difference between normal and oncogenic RAS pathway signaling, this study shows that oncogenic RAS specifically triggers constitutive endocytosis-dependent movement of effector kinases to a perinuclear region, thereby creating connections to unique downstream targets such as the core prosenescence and the inflammatory regulatory transcription factor C/EBPβ. Cancer Res; 78(4); 891-908. ©2017 AACR.
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Affiliation(s)
- Sandip K Basu
- Mouse Cancer Genetics Program, Center for Cancer Research, National Cancer Institute, Frederick, Maryland
| | - Sook Lee
- Mouse Cancer Genetics Program, Center for Cancer Research, National Cancer Institute, Frederick, Maryland
| | - Jacqueline Salotti
- Mouse Cancer Genetics Program, Center for Cancer Research, National Cancer Institute, Frederick, Maryland
| | - Srikanta Basu
- Mouse Cancer Genetics Program, Center for Cancer Research, National Cancer Institute, Frederick, Maryland
| | - Krisada Sakchaisri
- Mouse Cancer Genetics Program, Center for Cancer Research, National Cancer Institute, Frederick, Maryland
| | - Zhen Xiao
- Laboratory of Proteomics and Analytical Technologies, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland
| | - Vijay Walia
- Laboratory of Cell and Developmental Signaling, Center for Cancer Research, National Cancer Institute, Frederick, Maryland
| | - Christopher J Westlake
- Laboratory of Cell and Developmental Signaling, Center for Cancer Research, National Cancer Institute, Frederick, Maryland
| | - Deborah K Morrison
- Laboratory of Cell and Developmental Signaling, Center for Cancer Research, National Cancer Institute, Frederick, Maryland
| | - Peter F Johnson
- Mouse Cancer Genetics Program, Center for Cancer Research, National Cancer Institute, Frederick, Maryland.
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56
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Karabiyik C, Fernandes R, Figueiredo FR, Socodato R, Brakebusch C, Lambertsen KL, Relvas JB, Santos SD. Neuronal Rho GTPase Rac1 elimination confers neuroprotection in a mouse model of permanent ischemic stroke. Brain Pathol 2017; 28:569-580. [PMID: 28960571 DOI: 10.1111/bpa.12562] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Accepted: 09/21/2017] [Indexed: 01/08/2023] Open
Abstract
The Rho GTPase Rac1 is a multifunctional protein involved in distinct pathways ranging from development to pathology. The aim of the present study was to unravel the contribution of neuronal Rac1 in regulating the response to brain injury induced by permanent focal cerebral ischemia (pMCAO). Our results show that pMCAO significantly increased total Rac1 levels in wild type mice, mainly through rising nuclear Rac1, while a reduction in Rac1 activation was observed. Such changes preceded cell death induced by excitotoxic stress. Pharmacological inhibition of Rac1 in primary neuronal cortical cells prevented the increase in oxidative stress induced after overactivation of glutamate receptors. However, this was not sufficient to prevent the associated neuronal cell death. In contrast, RNAi-mediated knock down of Rac1 in primary cortical neurons prevented cell death elicited by glutamate excitotoxicity and decreased the activity of NADPH oxidase. To test whether in vivo down regulation of neuronal Rac1 was neuroprotective after pMCAO, we used tamoxifen-inducible neuron-specific conditional Rac1-knockout mice. We observed a significant 50% decrease in brain infarct volume of knockout mice and a concomitant increase in HIF-1α expression compared to littermate control mice, demonstrating that ablation of Rac1 in neurons is neuroprotective. Transmission electron microscopy performed in the ischemic brain showed that lysosomes in the infarct of Rac1- knockout mice were preserved at similar levels to those of non-infarcted tissue, while littermate mice displayed a decrease in the number of lysosomes, further corroborating the notion that Rac1 ablation in neurons is neuroprotective. Our results demonstrate that Rac1 plays important roles in the ischemic pathological cascade and that modulation of its levels is of therapeutic interest.
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Affiliation(s)
- Cansu Karabiyik
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,Glial Cell Biology, IBMC- Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal.,Department of Neurobiology Research, Institute of Molecular Medicine, University of Southern Denmark, Odense C, Denmark
| | - Rui Fernandes
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,HEMS, IBMC-Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
| | - Francisco Rosário Figueiredo
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,HEMS, IBMC-Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
| | - Renato Socodato
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,Glial Cell Biology, IBMC- Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
| | - Cord Brakebusch
- Biotech Research and Innovation Center, University of Copenhagen, Denmark
| | - Kate Lykke Lambertsen
- Department of Neurobiology Research, Institute of Molecular Medicine, University of Southern Denmark, Odense C, Denmark.,Department of Neurology, Odense University Hospital, Odence C, Denmark.,BRIDGE - Brain Research - Inter-Disciplinary Guided Excellence, Department of Clinical Research, University of Southern Denmark, Odense, Denmark
| | - João Bettencourt Relvas
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,Glial Cell Biology, IBMC- Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
| | - Sofia Duque Santos
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,Glial Cell Biology, IBMC- Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal.,INEB - Instituto de Engenharia Biomédica, Universidade do Porto, Porto, Portugal
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Modelling compartmentalization towards elucidation and engineering of spatial organization in biochemical pathways. Sci Rep 2017; 7:12057. [PMID: 28935941 PMCID: PMC5608717 DOI: 10.1038/s41598-017-11081-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 08/08/2017] [Indexed: 01/21/2023] Open
Abstract
Compartmentalization is a fundamental ingredient, central to the functioning of biological systems at multiple levels. At the cellular level, compartmentalization is a key aspect of the functioning of biochemical pathways and an important element used in evolution. It is also being exploited in multiple contexts in synthetic biology. Accurate understanding of the role of compartments and designing compartmentalized systems needs reliable modelling/systems frameworks. We examine a series of building blocks of signalling and metabolic pathways with compartmental organization. We systematically analyze when compartmental ODE models can be used in these contexts, by comparing these models with detailed reaction-transport models, and establishing a correspondence between the two. We build on this to examine additional complexities associated with these pathways, and also examine sample problems in the engineering of these pathways. Our results indicate under which conditions compartmental models can and cannot be used, why this is the case, and what augmentations are needed to make them reliable and predictive. We also uncover other hidden consequences of employing compartmental models in these contexts. Or results contribute a number of insights relevant to the modelling, elucidation, and engineering of biochemical pathways with compartmentalization, at the core of systems and synthetic biology.
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58
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Öztürk E, Despot-Slade E, Pichler M, Zenobi-Wong M. RhoA activation and nuclearization marks loss of chondrocyte phenotype in crosstalk with Wnt pathway. Exp Cell Res 2017; 360:113-124. [PMID: 28865751 DOI: 10.1016/j.yexcr.2017.08.033] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Revised: 08/20/2017] [Accepted: 08/29/2017] [Indexed: 12/24/2022]
Abstract
De-differentiation comprises a major drawback for the use of autologous chondrocytes in cartilage repair. Here, we investigate the role of RhoA and canonical Wnt signaling in chondrocyte phenotype. Chondrocyte de-differentiation is accompanied by an upregulation and nuclear localization of RhoA. Effectors of canonical Wnt signaling including β-catenin and YAP/TAZ are upregulated in de-differentiating chondrocytes in a Rho-dependent manner. Inhibition of Rho activation with C3 transferase inhibits nuclear localization of RhoA, induces expression of chondrogenic markers on 2D and enhances the chondrogenic effect of 3D culturing. Upregulation of chondrogenic markers by Rho inhibition is accompanied by loss of canonical Wnt signaling markers in 3D or on 2D whereas treatment of chondrocytes with Wnt-3a abrogates this effect. However, induction of canonical Wnt signaling inhibits chondrogenic markers on 2D but enhances chondrogenic re-differentiation on 2D with C3 transferase or in 3D. These data provide insights on the context-dependent role of RhoA and Wnt signaling in de-differentiation and on mechanisms to induce chondrogenic markers for therapeutic approaches.
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Affiliation(s)
- Ece Öztürk
- Cartilage Engineering + Regeneration Laboratory, ETH Zurich, Otto-Stern-Weg 7, 8093 Zurich, Switzerland
| | - Evelin Despot-Slade
- Cartilage Engineering + Regeneration Laboratory, ETH Zurich, Otto-Stern-Weg 7, 8093 Zurich, Switzerland
| | - Michael Pichler
- Cartilage Engineering + Regeneration Laboratory, ETH Zurich, Otto-Stern-Weg 7, 8093 Zurich, Switzerland
| | - Marcy Zenobi-Wong
- Cartilage Engineering + Regeneration Laboratory, ETH Zurich, Otto-Stern-Weg 7, 8093 Zurich, Switzerland.
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59
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Nussinov R, Jang H, Tsai CJ, Liao TJ, Li S, Fushman D, Zhang J. Intrinsic protein disorder in oncogenic KRAS signaling. Cell Mol Life Sci 2017; 74:3245-3261. [PMID: 28597297 PMCID: PMC11107717 DOI: 10.1007/s00018-017-2564-3] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Accepted: 06/01/2017] [Indexed: 12/18/2022]
Abstract
How Ras, and in particular its most abundant oncogenic isoform K-Ras4B, is activated and signals in proliferating cells, poses some of the most challenging questions in cancer cell biology. In this paper, we ask how intrinsically disordered regions in K-Ras4B and its effectors help promote proliferative signaling. Conformational disorder allows spanning long distances, supports hinge motions, promotes anchoring in membranes, permits segments to fulfil multiple roles, and broadly is crucial for activation mechanisms and intensified oncogenic signaling. Here, we provide an overview illustrating some of the key mechanisms through which conformational disorder can promote oncogenesis, with K-Ras4B signaling serving as an example. We discuss (1) GTP-bound KRas4B activation through membrane attachment; (2) how farnesylation and palmitoylation can promote isoform functional specificity; (3) calmodulin binding and PI3K activation; (4) how Ras activates its RASSF5 cofactor, thereby stimulating signaling of the Hippo pathway and repressing proliferation; and (5) how intrinsically disordered segments in Raf help its attachment to the membrane and activation. Collectively, we provide the first inclusive review of the roles of intrinsic protein disorder in oncogenic Ras-driven signaling. We believe that a broad picture helps to grasp and formulate key mechanisms in Ras cancer biology and assists in therapeutic intervention.
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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.
| | - 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
| | - 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
| | - Tsung-Jen Liao
- 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 Chemistry and Biochemistry, Center for Biomolecular Structure and Organization, University of Maryland, College Park, MD, 20742, USA
| | - Shuai Li
- Department of Pathophysiology, Shanghai Universities E-Institute for Chemical Biology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University, School of Medicine, Shanghai, 200025, China
| | - David Fushman
- Department of Chemistry and Biochemistry, Center for Biomolecular Structure and Organization, University of Maryland, College Park, MD, 20742, USA
| | - Jian Zhang
- Department of Pathophysiology, Shanghai Universities E-Institute for Chemical Biology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University, School of Medicine, Shanghai, 200025, China
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Azoulay-Alfaguter I, Strazza M, Peled M, Novak HK, Muller J, Dustin ML, Mor A. The tyrosine phosphatase SHP-1 promotes T cell adhesion by activating the adaptor protein CrkII in the immunological synapse. Sci Signal 2017; 10:10/491/eaal2880. [PMID: 28790195 DOI: 10.1126/scisignal.aal2880] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The adaptor protein CrkII regulates T cell adhesion by recruiting the guanine nucleotide exchange factor C3G, an activator of Rap1. Subsequently, Rap1 stimulates the integrin LFA-1, which leads to T cell adhesion and interaction with antigen-presenting cells (APCs). The adhesion of T cells to APCs is critical for their proper function and education. The interface between the T cell and the APC is known as the immunological synapse. It is characterized by the specific organization of proteins that can be divided into central supramolecular activation clusters (c-SMACs) and peripheral SMACs (p-SMACs). Through total internal reflection fluorescence (TIRF) microscopy and experiments with supported lipid bilayers, we determined that activated Rap1 was recruited to the immunological synapse and localized to the p-SMAC. C3G and the active (dephosphorylated) form of CrkII also localized to the same compartment. In contrast, inactive (phosphorylated) CrkII was confined to the c-SMAC. Activation of CrkII and its subsequent movement from the c-SMAC to the p-SMAC depended on the phosphatase SHP-1, which acted downstream of the T cell receptor. In the p-SMAC, CrkII recruited C3G, which led to Rap1 activation and LFA-1-mediated adhesion of T cells to APCs. Functionally, SHP-1 was necessary for both the adhesion and migration of T cells. Together, these data highlight a signaling pathway in which SHP-1 acts through CrkII to reshape the pattern of Rap1 activation in the immunological synapse.
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Affiliation(s)
| | - Marianne Strazza
- Department of Medicine, New York University School of Medicine, New York, NY 10016, USA
| | - Michael Peled
- Department of Medicine, New York University School of Medicine, New York, NY 10016, USA
| | - Hila K Novak
- Department of Pathology, New York University School of Medicine, New York, NY 10016, USA.,Kennedy Institute for Rheumatology, Oxford University, Oxford, UK
| | - James Muller
- Department of Pathology, New York University School of Medicine, New York, NY 10016, USA
| | - Michael L Dustin
- Department of Pathology, New York University School of Medicine, New York, NY 10016, USA.,Kennedy Institute for Rheumatology, Oxford University, Oxford, UK
| | - Adam Mor
- Department of Medicine, New York University School of Medicine, New York, NY 10016, USA. .,Department of Pathology, New York University School of Medicine, New York, NY 10016, USA.,Perlmutter Cancer Center, New York University School of Medicine, New York, NY 10016, USA
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Pawlina-Tyszko K, Gurgul A, Szmatoła T, Ropka-Molik K, Semik-Gurgul E, Klukowska-Rötzler J, Koch C, Mählmann K, Bugno-Poniewierska M. Genomic landscape of copy number variation and copy neutral loss of heterozygosity events in equine sarcoids reveals increased instability of the sarcoid genome. Biochimie 2017; 140:122-132. [PMID: 28743673 DOI: 10.1016/j.biochi.2017.07.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Accepted: 07/20/2017] [Indexed: 12/20/2022]
Abstract
Although they are the most common neoplasms in equids, sarcoids are not fully characterized at the molecular level. Therefore, the objective of this study was to characterize the landscape of structural rearrangements, such as copy number variation (CNV) and copy neutral loss of heterozygosity (cnLOH), in the genomes of sarcoid tumor cells. This information will not only broaden our understanding of the characteristics of this genome but will also improve the general knowledge of this tumor and the mechanisms involved in its generation. To this end, Equine SNP64K Illumina microarrays were applied along with bioinformatics tools dedicated for signal intensity analysis. The analysis revealed increased instability of the genome of sarcoid cells compared with unaltered skin tissue samples, which was manifested by the prevalence of CNV and cnLOH events. Many of the identified CNVs overlapped with the other research results, but the simultaneously observed variability in the number and sizes of detected aberrations indicated a need for further studies and the development of more reliable bioinformatics algorithms. The functional analysis of genes co-localized with the identified aberrations revealed that these genes are engaged in vital cellular processes. In addition, a number of these genes directly contribute to neoplastic transformation. Furthermore, large numbers of cnLOH events identified in the sarcoids suggested that they may play no less significant roles than CNVs in the carcinogenesis of this tumor. Thus, our results indicate the importance of cnLOH and CNV in equine sarcoid oncogenesis and present a direction of future research.
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Affiliation(s)
- Klaudia Pawlina-Tyszko
- Laboratory of Genomics, Department of Animal Genomics and Molecular Biology, National Research Institute of Animal Production, Krakowska 1, 32-083, Balice, Poland.
| | - Artur Gurgul
- Laboratory of Genomics, Department of Animal Genomics and Molecular Biology, National Research Institute of Animal Production, Krakowska 1, 32-083, Balice, Poland.
| | - Tomasz Szmatoła
- Laboratory of Genomics, Department of Animal Genomics and Molecular Biology, National Research Institute of Animal Production, Krakowska 1, 32-083, Balice, Poland.
| | - Katarzyna Ropka-Molik
- Laboratory of Genomics, Department of Animal Genomics and Molecular Biology, National Research Institute of Animal Production, Krakowska 1, 32-083, Balice, Poland.
| | - Ewelina Semik-Gurgul
- Laboratory of Genomics, Department of Animal Genomics and Molecular Biology, National Research Institute of Animal Production, Krakowska 1, 32-083, Balice, Poland.
| | - Jolanta Klukowska-Rötzler
- Division of Pedriatric Hematology/Oncology, Department of Clinical Research, University of Bern, Murtenstrasse 35, 3008, Bern, Switzerland; Department of Emergency Medicine, University Hospital Bern, Inselspital, 3010, Bern, Switzerland.
| | - Christoph Koch
- Swiss Institute of Equine Medicine ISME, Faculty of Veterinary Medicine, University of Bern and Agroscope, Länggassstrasse 124c, Postfach 8466, CH-3001, Bern, Switzerland.
| | - Kathrin Mählmann
- Swiss Institute of Equine Medicine ISME, Faculty of Veterinary Medicine, University of Bern and Agroscope, Länggassstrasse 124c, Postfach 8466, CH-3001, Bern, Switzerland; Equine Clinic: Surgery and Radiology, Department of Veterinary Medicine, Free University of Berlin, Oertzenweg 19b, 14163, Berlin, Germany.
| | - Monika Bugno-Poniewierska
- Laboratory of Genomics, Department of Animal Genomics and Molecular Biology, National Research Institute of Animal Production, Krakowska 1, 32-083, Balice, Poland.
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Franco A, Soto T, Martín-García R, Madrid M, Vázquez-Marín B, Vicente-Soler J, Coll PM, Gacto M, Pérez P, Cansado J. Distinct functional relevance of dynamic GTPase cysteine methylation in fission yeast. Sci Rep 2017; 7:6057. [PMID: 28729673 PMCID: PMC5519673 DOI: 10.1038/s41598-017-06053-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Accepted: 06/07/2017] [Indexed: 12/11/2022] Open
Abstract
The final step in post-translational processing of Ras and Rho GTPases involves methylation of the prenylated cysteine residue by an isoprenylcysteine-O-carboxyl methyltransferase (ICMT). ICMT activity is essential for cell growth and development in higher eukaryotes, and inhibition of GTPase methylation has become an attractive target in cancer therapy to inactivate prenylated oncoproteins. However, the specificity and dynamics of the GTPase methylation process remain to be fully clarified. Notably, cells lacking Mam4, the ICMT ortholog in the fission yeast Schizosaccharomyces pombe, are viable. We have exploited this feature to analyze the role of methylation on GTPase localization and function. We show that methylation differentially affects GTPase membrane localization, being particularly relevant for plasma membrane tethering and downstream signaling of palmitoylated and farnesylated GTPases Ras1 and Rho2 lacking C-terminal polybasic motifs. Indeed, Ras1 and Rho2 cysteine methylation is required for proper regulation of differentiation elicited by MAPK Spk1 and for stress-dependent activation of the cell integrity pathway (CIP) and its main effector MAPK Pmk1. Further, Mam4 negatively regulates TORC2 signaling by a cross-inhibitory mechanism relying on Rho GTPase methylation. These results highlight the requirement for a tight control of GTPase methylation in vivo to allow adequate GTPase function.
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Affiliation(s)
- Alejandro Franco
- Yeast Physiology Group, Department of Genetics and Microbiology, Facultad de Biología, Universidad de Murcia, 30071, Murcia, Spain
| | - Teresa Soto
- Yeast Physiology Group, Department of Genetics and Microbiology, Facultad de Biología, Universidad de Murcia, 30071, Murcia, Spain
| | - Rebeca Martín-García
- Instituto de Biología Funcional y Genómica (IBFG), Consejo Superior de Investigaciones Científicas/Departamento de Microbiología y Genética, Universidad de Salamanca, 37007, Salamanca, Spain
| | - Marisa Madrid
- Yeast Physiology Group, Department of Genetics and Microbiology, Facultad de Biología, Universidad de Murcia, 30071, Murcia, Spain
| | - Beatriz Vázquez-Marín
- Yeast Physiology Group, Department of Genetics and Microbiology, Facultad de Biología, Universidad de Murcia, 30071, Murcia, Spain
| | - Jero Vicente-Soler
- Yeast Physiology Group, Department of Genetics and Microbiology, Facultad de Biología, Universidad de Murcia, 30071, Murcia, Spain
| | - Pedro M Coll
- Instituto de Biología Funcional y Genómica (IBFG), Consejo Superior de Investigaciones Científicas/Departamento de Microbiología y Genética, Universidad de Salamanca, 37007, Salamanca, Spain
| | - Mariano Gacto
- Yeast Physiology Group, Department of Genetics and Microbiology, Facultad de Biología, Universidad de Murcia, 30071, Murcia, Spain
| | - Pilar Pérez
- Instituto de Biología Funcional y Genómica (IBFG), Consejo Superior de Investigaciones Científicas/Departamento de Microbiología y Genética, Universidad de Salamanca, 37007, Salamanca, Spain
| | - José Cansado
- Yeast Physiology Group, Department of Genetics and Microbiology, Facultad de Biología, Universidad de Murcia, 30071, Murcia, Spain.
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Abstract
The Ras proteins are well-known drivers of many cancers and thus represent attractive targets for the development of anticancer therapeutics. Inhibitors that disrupt the association of the Ras proteins with membranes by blocking the addition of the farnesyl lipid moiety to the Ras C-terminus failed in clinical trials. Here, we explore the possibility of targeting a second lipid modification, S-acylation, commonly referred to as palmitoylation, as a strategy to disrupt the membrane interaction of specific Ras isoforms. We review the enzymes involved in adding and removing palmitate from Ras and discuss their potential roles in regulating Ras tumorigenesis. In addition, we examine other proteins that affect Ras protein localization and may serve as future drug targets.
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64
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Shi B, Zhou X, He L, Liang M, Luo Y, Jiang P. Reduced RCE1 expression predicts poor prognosis of colorectal carcinoma. BMC Cancer 2017; 17:414. [PMID: 28615075 PMCID: PMC5471898 DOI: 10.1186/s12885-017-3393-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Accepted: 05/26/2017] [Indexed: 12/30/2022] Open
Abstract
Background As an end-proteolytic enzyme that cleaves the last three residues of proteins with a terminal CAAX, Ras-converting enzyme 1 (RCE1) has an essential role in multiple signaling pathways and take part in the process of differentiation, proliferation and carcinogenesis. The aim of the study is to investigate expression pattern of RCE1 and its prognosis in colorectal carcinoma (CRC). Methods The expression of RCE1 and phospho-MAPK family members was confirmed by immunohistochemical staining of CRC tissues. miR-RCE1 lentiviral vectors were transduced into HCT116 and SW489 cells. Reverse transcription PCR (RT-PCR) and western blot were conducted to measure the transfection efficiency. Transwell assays were used to detect the invasiveness of CRC cells. Results In the present study, we assessed RCE1 expression in 244 CRC specimens and matching adjacent, non-tumorous tissues by immunohistochemistry (IHC). Compared with the matched adjacent non-tumor tissue samples, the RCE1 reduced in the tumor tissue samples (p < 0.001). RCE1 expression was significantly decreased in 106 of 244 (43.4%) CRC cases. In univariate and multivariate analyses, Decreasing expression of RCE1 independently predicts poor prognosis for patients in both overall survival and disease-free survival. Further study indicated that RCE1 influenced tumor invasion through the p38 pathway. Knockdown of RCE1 reduced phosphorylation and significantly increased the invasive capacity of CRC cells. Conclusion Taken together, the outcomes of this study indicate that RCE1 acts as a tumor suppressor in CRC, as its reduced expression may increase CRC cell invasion and independently predict an unsatisfactory prognosis in CRC patients. Electronic supplementary material The online version of this article (doi:10.1186/s12885-017-3393-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Boyun Shi
- Department of Oncology, The Fifth Affiliated Hospital, Guangzhou Medical University, 621 Harbor Road, Guangzhou, Guangdong, 510700, China
| | - Xinke Zhou
- Department of Oncology, The Fifth Affiliated Hospital, Guangzhou Medical University, 621 Harbor Road, Guangzhou, Guangdong, 510700, China.
| | - Lu He
- Department of Radiotherapy, Affiliated Tumour Hospital, Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Min Liang
- Department of Oncology, The Fifth Affiliated Hospital, Guangzhou Medical University, 621 Harbor Road, Guangzhou, Guangdong, 510700, China
| | - Yuanwei Luo
- Department of Oncology, The Fifth Affiliated Hospital, Guangzhou Medical University, 621 Harbor Road, Guangzhou, Guangdong, 510700, China
| | - Peng Jiang
- Department of Radiotherapy, Affiliated Tumour Hospital, Guangzhou Medical University, Guangzhou, Guangdong, China
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Boespflug A, Caramel J, Dalle S, Thomas L. Treatment of NRAS-mutated advanced or metastatic melanoma: rationale, current trials and evidence to date. Ther Adv Med Oncol 2017; 9:481-492. [PMID: 28717400 PMCID: PMC5502949 DOI: 10.1177/1758834017708160] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Accepted: 04/13/2017] [Indexed: 12/19/2022] Open
Abstract
The disease course of BRAF (v-raf murine sarcoma viral oncogene homolog B1)-mutant melanoma has been drastically improved by the arrival of targeted therapies. NRAS (neuroblastoma RAS viral oncogene homolog)-mutated melanoma represents 15–25% of all metastatic melanoma patients. It currently does not have an approved targeted therapy. Metastatic patients receive immune-based therapies as first-line treatments, then cytotoxic chemotherapy like carboplatin/paclitaxel (C/P), dacarbazine (DTIC) or temozolomide (TMZ) as a second-line treatment. We will review current preclinical and clinical developments in NRAS-mutated melanoma, and analyze ongoing clinical trials that are evaluating the benefit of different targeted and immune-based therapies, either tested as single agents or in combination, in NRAS-mutant melanoma.
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Affiliation(s)
| | - Julie Caramel
- Cancer Research Center of Lyon, Claude Bernard Lyon-1 University, INSERM1052, CNRS 5286, Lyon, France
| | | | - Luc Thomas
- Service de Dermatologie, CH Lyon Sud, 165 Chemin du Grand Revoyet, 69495 Pierre Bénite, Cedex, France
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66
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Gu Q, Guo S, Wang D, Zhou T, Wang L, Wang Z, Ma J. Effect of corticision on orthodontic tooth movement in a rat model as assessed by RNA sequencing. J Mol Histol 2017; 48:199-208. [PMID: 28409326 DOI: 10.1007/s10735-017-9718-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Accepted: 03/20/2017] [Indexed: 12/23/2022]
Abstract
Corticision is a common technique to accelerate orthodontic tooth movement; however, not much is known about the underlying mechanisms. In this study, we investigated the mechanism of alveolar tissue remodeling after corticision in a rat model of tooth movement (TM) by analyzing the differential transcriptome. A total of 36 male rats were equally divided into TM and TM with corticision (TM+C) groups. Alveolar bone response was examined using micro-computed tomography (micro-CT). Osteoclasts and osteoblasts were quantified on tartrate-resistant acid phosphatase (TRAP) and Goldner's trichrome staining. The transcriptomes of alveolus around the left maxillary first molar were determined on RNA sequencing (RNA-Seq), and the expression of selected differentially expressed genes (DEGs) validated on quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR). Immunohistochemical examination of alveolar tissue was performed to examine the expressions of correlative proteins of the selected signaling pathway in the TM and TM+C groups. The ratio of bone volume to total volume (BV/TV), and the trabecular number (Tb.N) were significantly decreased, while the movement distance and the trabecular separation (Tb.Sp) was significantly increased in the TM+C group. However, no significant between-group difference in trabecular thickness (Tb.Th) was observed. On histomorphometric analysis, a significant increase in the number of osteoclasts and increased bone resorption was observed in the TM+C group. A total of 399 DEGs were identified on RNA-SEq. Eleven selected genes were confirmed on qRT-PCR, which included components of the Ras signaling pathway. Four proteins of the Ras signaling pathway showed a higher expression in the TM+C group. Our findings indicate that corticision may speed up orthodontic tooth movement by accelerating osteoclastogenesis mediated via the Ras signaling pathway.
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Affiliation(s)
- Qihui Gu
- Jiangsu Key Laboratory of Oral Diseases, Nanjing Medical University, 136 Hanzhong Road, Nanjing, Jiangsu, 210029, China
| | - Shuyu Guo
- Jiangsu Key Laboratory of Oral Diseases, Nanjing Medical University, 136 Hanzhong Road, Nanjing, Jiangsu, 210029, China
| | - Dongyue Wang
- Jiangsu Key Laboratory of Oral Diseases, Nanjing Medical University, 136 Hanzhong Road, Nanjing, Jiangsu, 210029, China
| | - Tingting Zhou
- Jiangsu Key Laboratory of Oral Diseases, Nanjing Medical University, 136 Hanzhong Road, Nanjing, Jiangsu, 210029, China
| | - Lin Wang
- Jiangsu Key Laboratory of Oral Diseases, Nanjing Medical University, 136 Hanzhong Road, Nanjing, Jiangsu, 210029, China
| | - Zhendong Wang
- Jiangsu Key Laboratory of Oral Diseases, Nanjing Medical University, 136 Hanzhong Road, Nanjing, Jiangsu, 210029, China.
| | - Junqing Ma
- Jiangsu Key Laboratory of Oral Diseases, Nanjing Medical University, 136 Hanzhong Road, Nanjing, Jiangsu, 210029, China.
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Crescenzi A, Fulciniti F, Bongiovanni M, Giovanella L, Trimboli P. Detecting N-RAS Q61R Mutated Thyroid Neoplasias by Immunohistochemistry. Endocr Pathol 2017; 28:71-74. [PMID: 28064410 DOI: 10.1007/s12022-016-9466-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Recently, the immunohistochemistry (IHC) for N-RAS Q61R has been developed and commercialized for clinical practice. Here, we investigated the reliability of IHC to identify N-RAS Q61R mutated thyroid neoplasia. A series of 24 consecutive thyroid lesions undergone surgery following indeterminate cytology were enrolled. Paraffin sections were stained for IHC using the rabbit monoclonal anti-human N-RAS Q61R, clone SP174. N-RAS mutations in codon 61 were also investigated by automated sequencing. At histology, 12 cases of follicular carcinoma, cytologically defined as follicular lesions, 1 papillary cancer, 7 follicular adenomas, and 4 hyperplastic nodules were found. Of these, 4 showed a positive IHC for anti N-RAS antibody where N-RAS expression was detected mainly at cytoplasmic level with similar intensity of reaction. The remaining cases had negative IHC. A 100% concordance between IHC and molecular analysis for N-RAS Q61R was observed. In conclusion, this study shows high reliability of IHC to identify N-RAS Q61R mutated thyroid lesions with high cost-effectiveness. These data indicate the reliability of IHC to identify N-RAS Q61R mutated thyroid neoplasia and suggest to adopt this approach for a more accurate management of patients, when indicated.
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Affiliation(s)
- A Crescenzi
- Section of Pathology, University Hospital Campus Bio Medico, Rome, Italy
| | - F Fulciniti
- Pathology Institute of Locarno, Locarno, Switzerland
| | - M Bongiovanni
- Institute of Pathology, University Hospital, Lausanne, Switzerland
| | - L Giovanella
- Department of Nuclear Medicine and Thyroid Centre, Oncology Institute of Southern Switzerland, Bellinzona, Switzerland
| | - Pierpaolo Trimboli
- Department of Nuclear Medicine and Thyroid Centre, Oncology Institute of Southern Switzerland, Bellinzona, Switzerland.
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68
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Lubeseder-Martellato C, Alexandrow K, Hidalgo-Sastre A, Heid I, Boos SL, Briel T, Schmid RM, Siveke JT. Oncogenic KRas-induced Increase in Fluid-phase Endocytosis is Dependent on N-WASP and is Required for the Formation of Pancreatic Preneoplastic Lesions. EBioMedicine 2017; 15:90-99. [PMID: 28057438 PMCID: PMC5233824 DOI: 10.1016/j.ebiom.2016.12.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Revised: 11/28/2016] [Accepted: 12/20/2016] [Indexed: 01/13/2023] Open
Abstract
Fluid-phase endocytosis is a homeostatic process with an unknown role in tumor initiation. The driver mutation in pancreatic ductal adenocarcinoma (PDAC) is constitutively active KRasG12D, which induces neoplastic transformation of acinar cells through acinar-to-ductal metaplasia (ADM). We have previously shown that KRasG12D-induced ADM is dependent on RAC1 and EGF receptor (EGFR) by a not fully clarified mechanism. Using three-dimensional mouse and human acinar tissue cultures and genetically engineered mouse models, we provide evidence that (i) KRasG12D leads to EGFR-dependent sustained fluid-phase endocytosis (FPE) during acinar metaplasia; (ii) variations in plasma membrane tension increase FPE and lead to ADM in vitro independently of EGFR; and (iii) that RAC1 regulates ADM formation partially through actin-dependent regulation of FPE. In addition, mice with a pancreas-specific deletion of the Neural-Wiskott-Aldrich syndrome protein (N-WASP), a regulator of F-actin, have reduced FPE and impaired ADM emphasizing the in vivo relevance of our findings. This work defines a new role of FPE as a tumor initiating mechanism.
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Affiliation(s)
- Clara Lubeseder-Martellato
- Clinic and Polyclinic for Internal Medicine II, Klinikum Rechts der Isar, Technical University of Munich, Germany.
| | - Katharina Alexandrow
- Clinic and Polyclinic for Internal Medicine II, Klinikum Rechts der Isar, Technical University of Munich, Germany
| | - Ana Hidalgo-Sastre
- Clinic and Polyclinic for Internal Medicine II, Klinikum Rechts der Isar, Technical University of Munich, Germany
| | - Irina Heid
- Institute of Radiology, Klinikum Rechts der Isar, Technical University of Munich, Germany
| | - Sophie Luise Boos
- Clinic and Polyclinic for Internal Medicine II, Klinikum Rechts der Isar, Technical University of Munich, Germany; German Cancer Consortium (DKTK) and German Cancer Research Center, DKFZ, Heidelberg, Germany
| | - Thomas Briel
- Clinic and Polyclinic for Internal Medicine II, Klinikum Rechts der Isar, Technical University of Munich, Germany
| | - Roland M Schmid
- Clinic and Polyclinic for Internal Medicine II, Klinikum Rechts der Isar, Technical University of Munich, Germany; German Cancer Consortium (DKTK) and German Cancer Research Center, DKFZ, Heidelberg, Germany
| | - Jens T Siveke
- Clinic and Polyclinic for Internal Medicine II, Klinikum Rechts der Isar, Technical University of Munich, Germany; German Cancer Consortium (DKTK) and German Cancer Research Center, DKFZ, Heidelberg, Germany; Division of Solid Tumor Translational Oncology, German Cancer Consortium (DKTK), Partner Site Essen, West German Cancer Center, University Hospital Essen, Germany.
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69
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Immunological Disorders: Regulation of Ca 2+ Signaling in T Lymphocytes. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 993:397-424. [PMID: 28900926 DOI: 10.1007/978-3-319-57732-6_21] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Engagement of T cell receptors (TCRs) with cognate antigens triggers cascades of signaling pathways in helper T cells. TCR signaling is essential for the effector function of helper T cells including proliferation, differentiation, and cytokine production. It also modulates effector T cell fate by inducing cell death, anergy (nonresponsiveness), exhaustion, and generation of regulatory T cells. One of the main axes of TCR signaling is the Ca2+-calcineurin-nuclear factor of activated T cells (NFAT) signaling pathway. Stimulation of TCRs triggers depletion of intracellular Ca2+ store and, in turn, activates store-operated Ca2+ entry (SOCE) to raise the intracellular Ca2+ concentration. SOCE in T cells is mediated by the Ca2+ release-activated Ca2+ (CRAC) channels, which have been very well characterized in terms of their electrophysiological properties. Identification of STIM1 as a sensor to detect depletion of the endoplasmic reticulum (ER) Ca2+ store and Orai1 as the pore subunit of CRAC channels has dramatically advanced our understanding of the regulatory mechanism of Ca2+ signaling in T cells. In this review, we discuss our current understanding of Ca2+ signaling in T cells with specific focus on the mechanism of CRAC channel activation and regulation via protein interactions. In addition, we will discuss the role of CRAC channels in effector T cells, based on the analyses of genetically modified animal models.
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70
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Ras Proteolipid Nanoassemblies on the Plasma Membrane Sort Lipids With High Selectivity. ACTA ACUST UNITED AC 2017. [DOI: 10.1016/bs.abl.2017.01.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
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71
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Cheng D, Deobagkar-Lele M, Zvezdova E, Choi S, Uehara S, Baup D, Bennett SC, Bull KR, Crockford TL, Ferry H, Warzecha C, Marcellin M, de Peredo AG, Lesourne R, Anzilotti C, Love PE, Cornall RJ. Themis2 lowers the threshold for B cell activation during positive selection. Nat Immunol 2016; 18:205-213. [PMID: 27992403 DOI: 10.1038/ni.3642] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Accepted: 11/22/2016] [Indexed: 12/21/2022]
Abstract
The positive and negative selection of lymphocytes by antigen is central to adaptive immunity and self-tolerance, yet how this is determined by different antigens is not completely understood. We found that thymocyte-selection-associated family member 2 (Themis2) increased the positive selection of B1 cells and germinal center B cells by self and foreign antigens. Themis2 lowered the threshold for B-cell activation by low-avidity, but not high-avidity, antigens. Themis2 constitutively bound the adaptor protein Grb2, src-kinase Lyn and signal transducer phospholipase γ2 (PLC-γ2), and increased activation of PLC-γ2 and its downstream pathways following B cell receptor stimulation. Our findings identify a unique function for Themis2 in differential signaling and provide insight into how B cells discriminate between antigens of different quantity and quality.
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Affiliation(s)
- Daian Cheng
- MRC Human Immunology Unit, Weatherall Institute for Molecular Medicine, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Mukta Deobagkar-Lele
- MRC Human Immunology Unit, Weatherall Institute for Molecular Medicine, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Ekaterina Zvezdova
- Section on Hematopoiesis and Lymphocyte Biology, Eunice Kennedy Shriver, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, USA
| | - Seeyoung Choi
- Section on Hematopoiesis and Lymphocyte Biology, Eunice Kennedy Shriver, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, USA
| | - Shoji Uehara
- Section on Hematopoiesis and Lymphocyte Biology, Eunice Kennedy Shriver, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, USA
| | - Delphine Baup
- MRC Human Immunology Unit, Weatherall Institute for Molecular Medicine, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Sophia C Bennett
- MRC Human Immunology Unit, Weatherall Institute for Molecular Medicine, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Katherine R Bull
- MRC Human Immunology Unit, Weatherall Institute for Molecular Medicine, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Tanya L Crockford
- MRC Human Immunology Unit, Weatherall Institute for Molecular Medicine, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Helen Ferry
- MRC Human Immunology Unit, Weatherall Institute for Molecular Medicine, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Claude Warzecha
- Section on Hematopoiesis and Lymphocyte Biology, Eunice Kennedy Shriver, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, USA
| | - Marlène Marcellin
- Institut de Pharmacologie et de Biologie Structurale and Université de Toulouse, Université Paul Sabatier, Centre National de la Recherche Scientifique, Toulouse, France
| | - Anne Gonzalez de Peredo
- Institut de Pharmacologie et de Biologie Structurale and Université de Toulouse, Université Paul Sabatier, Centre National de la Recherche Scientifique, Toulouse, France
| | - Renaud Lesourne
- Centre de Physiopathologie de Toulouse Purpan, Toulouse, France; and Institut National de la Santé et de la Recherche Médicale, U1043, Centre National de la Recherche Scientifique, and Université de Toulouse, Université Paul Sabatier, Toulouse, France
| | - Consuelo Anzilotti
- MRC Human Immunology Unit, Weatherall Institute for Molecular Medicine, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Paul E Love
- Section on Hematopoiesis and Lymphocyte Biology, Eunice Kennedy Shriver, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, USA
| | - Richard J Cornall
- MRC Human Immunology Unit, Weatherall Institute for Molecular Medicine, Nuffield Department of Medicine, University of Oxford, Oxford, UK
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Hentschel A, Zahedi RP, Ahrends R. Protein lipid modifications--More than just a greasy ballast. Proteomics 2016; 16:759-82. [PMID: 26683279 DOI: 10.1002/pmic.201500353] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2015] [Revised: 10/24/2015] [Accepted: 12/14/2015] [Indexed: 12/21/2022]
Abstract
Covalent lipid modifications of proteins are crucial for regulation of cellular plasticity, since they affect the chemical and physical properties and therefore protein activity, localization, and stability. Most recently, lipid modifications on proteins are increasingly attracting important regulatory entities in diverse signaling events and diseases. In all cases, the lipid moiety of modified proteins is essential to allow water-soluble proteins to strongly interact with membranes or to induce structural changes in proteins that are critical for elemental processes such as respiration, transport, signal transduction, and motility. Until now, roughly about ten lipid modifications on different amino acid residues are described at the UniProtKB database and even well-known modifications are underrepresented. Thus, it is of fundamental importance to develop a better understanding of this emerging and so far under-investigated type of protein modification. Therefore, this review aims to give a comprehensive and detailed overview about enzymatic and nonenzymatic lipidation events, will report their role in cellular biology, discuss their relevancy for diseases, and describe so far available bioanalytical strategies to analyze this highly challenging type of modification.
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Affiliation(s)
- Andreas Hentschel
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V, Dortmund, Germany
| | - René P Zahedi
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V, Dortmund, Germany
| | - Robert Ahrends
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V, Dortmund, Germany
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Feng L, Xue D, Chen E, Zhang W, Gao X, Yu J, Feng Y, Pan Z. HMGB1 promotes the secretion of multiple cytokines and potentiates the osteogenic differentiation of mesenchymal stem cells through the Ras/MAPK signaling pathway. Exp Ther Med 2016; 12:3941-3947. [PMID: 28105126 PMCID: PMC5228376 DOI: 10.3892/etm.2016.3857] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Accepted: 04/06/2016] [Indexed: 12/19/2022] Open
Abstract
High mobility group box 1 (HMGB1) protein has been previously been detected in the inflammatory microenvironment of bone fractures. It is well known that HMGB1 acts as a chemoattractant to mesenchymal stem cells (MSCs). In the present study, the effects of HMGB1 on cytokine secretion from MSCs were determined, and the molecular mechanisms underlying these effects of HMGB1 on osteogenic differentiation were elucidated. To detect cytokine secretion, antibody array assays were performed, which demonstrated that HGMB1 induced the differential secretion of cytokines that are predominantly associated with cell development, regulation of growth and cell migration, stress responses, and immune system functions. Moreover, the secretion of epidermal growth factor receptor (EGFR) was significantly upregulated by HMGB1. The EGFR-activated Ras/MAPK pathway regulates the osteogenic differentiation of MSCs. These results suggested that HMGB1 enhances the secretion of various cytokines by MSCs and promotes osteogenic differentiation via the Ras/MAPK signaling pathway. The present study may provide a theoretical basis for the development of novel techniques for the treatment of bone fractures in the future.
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Affiliation(s)
- Lin Feng
- Department of Orthopedics, The First People's Hospital of Xiaoshan, Hangzhou, Zhejiang 311200, P.R. China
| | - Deting Xue
- Department of Orthopedics, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310009, P.R. China
| | - Erman Chen
- Department of Orthopedics, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310009, P.R. China
| | - Wei Zhang
- Department of Orthopedics, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310009, P.R. China
| | - Xiang Gao
- Department of Orthopedics, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310009, P.R. China
| | - Jiawei Yu
- Department of Orthopedics, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310009, P.R. China
| | - Yadong Feng
- Department of Orthopedics, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310009, P.R. China
| | - Zhijun Pan
- Department of Orthopedics, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310009, P.R. China
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Cunningham CA, Cardwell LN, Guan Y, Teixeiro E, Daniels MA. POSH Regulates CD4+ T Cell Differentiation and Survival. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2016; 196:4003-13. [PMID: 27084103 PMCID: PMC4868786 DOI: 10.4049/jimmunol.1501728] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Accepted: 03/14/2016] [Indexed: 12/24/2022]
Abstract
The scaffold molecule POSH is crucial for the regulation of proliferation and effector function in CD8(+) T cells. However, its role in CD4(+) T cells is not known. In this study, we found that disruption of the POSH scaffold complex established a transcriptional profile that strongly skewed differentiation toward Th2, led to decreased survival, and had no effect on cell cycle entry. This is in stark contrast to CD8(+) T cells in which POSH regulates cell cycle and does not affect survival. Disruption of POSH in CD4(+) T cells resulted in the loss of Tak1-dependent activation of JNK1/2 and Tak1-mediated survival. However, in CD8(+) T cells, POSH regulates only JNK1. Remarkably, each type of T cell had a unique composition of the POSH scaffold complex and distinct posttranslational modifications of POSH. These data indicate that the mechanism that regulates POSH function in CD4(+) T cells is different from CD8(+) T cells. All together, these data strongly suggest that POSH is essential for the integration of cell-type-specific signals that regulate the differentiation, survival, and function of T cells.
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Affiliation(s)
- Cody A Cunningham
- Department of Molecular Microbiology and Immunology, School of Medicine, University of Missouri, Columbia, MO 65212
| | - Leah N Cardwell
- Department of Molecular Microbiology and Immunology, School of Medicine, University of Missouri, Columbia, MO 65212
| | - Yue Guan
- Department of Molecular Microbiology and Immunology, School of Medicine, University of Missouri, Columbia, MO 65212
| | - Emma Teixeiro
- Department of Molecular Microbiology and Immunology, School of Medicine, University of Missouri, Columbia, MO 65212
| | - Mark A Daniels
- Department of Molecular Microbiology and Immunology, School of Medicine, University of Missouri, Columbia, MO 65212
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75
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Mues M, Roose JP. Distinct oncogenic Ras signals characterized by profound differences in flux through the RasGDP/RasGTP cycle. Small GTPases 2016; 8:20-25. [PMID: 27159504 DOI: 10.1080/21541248.2016.1187323] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
T cell acute lymphoblastic leukemia/lymphoma (T-ALL) is an aggressive bone marrow cancer in children and adults, and chemotherapy often fails for relapsing patients. Molecularly targeted therapy is hindered by heterogeneity in T-ALL and mechanistic details of the affected pathways in T-ALL are needed. Deregulation of Ras signals is common in T-ALL. Ras is genetically mutated to a constitutively active form in about 15% of all haematopoietic malignancies, but there is a range of other ways to augment signaling through the Ras pathway. Several groups including our own uncovered that RasGRP1 overexpression leads to T-ALL in mouse models and in pediatric T-ALL patients, and we reported that this Ras guanine nucleotide exchange factor, RasGRP1, cooperates with cytokines to drive leukemogenesis. In our recent study by Ksionda et al. we analyzed the molecular details of cytokine receptor-RasGRP1-Ras signals in T-ALL and compared these to signals from mutated Ras alleles, which yielded several surprising results. Examples are the striking differences in flux through the RasGDP/RasGTP cycle in distinct T-ALL or unexpected differences in wiring of the Ras signaling pathway between T-ALL and normal developing T cells, which we will discuss here.
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Affiliation(s)
- Marsilius Mues
- a Department of Anatomy , University of California San Francisco , San Francisco , CA , USA
| | - Jeroen P Roose
- a Department of Anatomy , University of California San Francisco , San Francisco , CA , USA
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76
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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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77
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Christensen SM, Triplet MG, Rhodes C, Iwig JS, Tu HL, Stamou D, Groves JT. Monitoring the Waiting Time Sequence of Single Ras GTPase Activation Events Using Liposome Functionalized Zero-Mode Waveguides. NANO LETTERS 2016; 16:2890-5. [PMID: 27013033 PMCID: PMC5515077 DOI: 10.1021/acs.nanolett.6b00969] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Activation of small GTPases of the Ras superfamily by guanine nucleotide exchange factors (GEFs) is a key step in numerous cell signaling processes. Unveiling the detailed molecular mechanisms of GEF-GTPase signaling interactions is of great importance due to their central roles in cell biology, including critical disease states, and their potential as therapeutic targets. Here we present an assay to monitor individual Ras activation events catalyzed by single molecules of the GEF Son of Sevenless (SOS) in the natural membrane environment. The assay employs zero-mode waveguide (ZMW) nanostructures containing a single Ras-functionalized liposome. The ZMWs facilitate highly localized excitation of fluorophores in the vicinity of the liposome membrane, allowing direct observation of individual Ras activation events as single SOS enzymes catalyze exchange of unlabeled nucleotides bound to Ras with fluorescently labeled nucleotides from solution. The system is compatible with continuous recording of long sequences of individual enzymatic turnover events over hour-long time scales. The single turnover waiting time sequence is a molecular footprint that details the temporal characteristics of the system. Data reported here reveal long-lived activity states that correspond to well-defined conformers of SOS at the membrane. Liposome functionalized ZMWs allow for studies of nucleotide exchange reactions at single GTPase resolution, providing a platform to gauge the mechanisms of these processes.
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Affiliation(s)
- Sune M. Christensen
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - Meredith G. Triplet
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - Christopher Rhodes
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - Jeffrey S. Iwig
- Howard Hughes Medical Institute, Department of Molecular and Cell Biology, University of California, Berkeley, California 94720, United States
| | - Hsiung-Lin Tu
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - Dimitrios Stamou
- Department of Chemistry and Nano-Science Center, University of Copenhagen, Copenhagen, Denmark
| | - Jay T. Groves
- Department of Chemistry, University of California, Berkeley, California 94720, United States
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78
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Jang H, Banerjee A, Chavan TS, Lu S, Zhang J, Gaponenko V, Nussinov R. The higher level of complexity of K-Ras4B activation at the membrane. FASEB J 2016; 30:1643-55. [PMID: 26718888 PMCID: PMC4799498 DOI: 10.1096/fj.15-279091] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Accepted: 12/14/2015] [Indexed: 12/19/2022]
Abstract
Is nucleotide exchange sufficient to activate K-Ras4B? To signal, oncogenic rat sarcoma (Ras) anchors in the membrane and recruits effectors by exposing its effector lobe. With the use of NMR and molecular dynamics (MD) simulations, we observed that in solution, farnesylated guanosine 5'-diphosphate (GDP)-bound K-Ras4B is predominantly autoinhibited by its hypervariable region (HVR), whereas the GTP-bound state favors an activated, HVR-released state. On the anionic membrane, the catalytic domain adopts multiple orientations, including parallel (∼180°) and perpendicular (∼90°) alignments of the allosteric helices, with respect to the membrane surface direction. In the autoinhibited state, the HVR is sandwiched between the effector lobe and the membrane; in the active state, with membrane-anchored farnesyl and unrestrained HVR, the catalytic domain fluctuates reinlessly, exposing its effector-binding site. Dimerization and clustering can reduce the fluctuations. This achieves preorganized, productive conformations. Notably, we also observe HVR-autoinhibited K-Ras4B-GTP states, with GDP-bound-like orientations of the helices. Thus, we propose that the GDP/GTP exchange may not be sufficient for activation; instead, our results suggest that the GDP/GTP exchange, HVR sequestration, farnesyl insertion, and orientation/localization of the catalytic domain at the membrane conjointly determine the active or inactive state of K-Ras4B. Importantly, K-Ras4B-GTP can exist in active and inactive states; on its own, GTP binding may not compel K-Ras4B activation.-Jang, H., Banerjee, A., Chavan, T. S, Lu, S., Zhang, J., Gaponenko, V., Nussinov, R. The higher level of complexity of K-Ras4B activation at the membrane.
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Affiliation(s)
- Hyunbum Jang
- *Basic Science Program, Leidos Biomedical Research, Frederick National Laboratory for Cancer Research, Cancer and Inflammation Program, National Cancer Institute at Frederick, Frederick, Maryland, USA; Department of Chemistry, Department of Medicinal Chemistry, and Department of Biochemistry and Molecular Genetics, University of Illinois at Chicago, Chicago, Illinois, USA; Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis, Chinese Ministry of Education, Shanghai JiaoTong University, School of Medicine, Shanghai, China; and Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Avik Banerjee
- *Basic Science Program, Leidos Biomedical Research, Frederick National Laboratory for Cancer Research, Cancer and Inflammation Program, National Cancer Institute at Frederick, Frederick, Maryland, USA; Department of Chemistry, Department of Medicinal Chemistry, and Department of Biochemistry and Molecular Genetics, University of Illinois at Chicago, Chicago, Illinois, USA; Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis, Chinese Ministry of Education, Shanghai JiaoTong University, School of Medicine, Shanghai, China; and Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Tanmay S Chavan
- *Basic Science Program, Leidos Biomedical Research, Frederick National Laboratory for Cancer Research, Cancer and Inflammation Program, National Cancer Institute at Frederick, Frederick, Maryland, USA; Department of Chemistry, Department of Medicinal Chemistry, and Department of Biochemistry and Molecular Genetics, University of Illinois at Chicago, Chicago, Illinois, USA; Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis, Chinese Ministry of Education, Shanghai JiaoTong University, School of Medicine, Shanghai, China; and Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Shaoyong Lu
- *Basic Science Program, Leidos Biomedical Research, Frederick National Laboratory for Cancer Research, Cancer and Inflammation Program, National Cancer Institute at Frederick, Frederick, Maryland, USA; Department of Chemistry, Department of Medicinal Chemistry, and Department of Biochemistry and Molecular Genetics, University of Illinois at Chicago, Chicago, Illinois, USA; Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis, Chinese Ministry of Education, Shanghai JiaoTong University, School of Medicine, Shanghai, China; and Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Jian Zhang
- *Basic Science Program, Leidos Biomedical Research, Frederick National Laboratory for Cancer Research, Cancer and Inflammation Program, National Cancer Institute at Frederick, Frederick, Maryland, USA; Department of Chemistry, Department of Medicinal Chemistry, and Department of Biochemistry and Molecular Genetics, University of Illinois at Chicago, Chicago, Illinois, USA; Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis, Chinese Ministry of Education, Shanghai JiaoTong University, School of Medicine, Shanghai, China; and Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Vadim Gaponenko
- *Basic Science Program, Leidos Biomedical Research, Frederick National Laboratory for Cancer Research, Cancer and Inflammation Program, National Cancer Institute at Frederick, Frederick, Maryland, USA; Department of Chemistry, Department of Medicinal Chemistry, and Department of Biochemistry and Molecular Genetics, University of Illinois at Chicago, Chicago, Illinois, USA; Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis, Chinese Ministry of Education, Shanghai JiaoTong University, School of Medicine, Shanghai, China; and Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Ruth Nussinov
- *Basic Science Program, Leidos Biomedical Research, Frederick National Laboratory for Cancer Research, Cancer and Inflammation Program, National Cancer Institute at Frederick, Frederick, Maryland, USA; Department of Chemistry, Department of Medicinal Chemistry, and Department of Biochemistry and Molecular Genetics, University of Illinois at Chicago, Chicago, Illinois, USA; Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis, Chinese Ministry of Education, Shanghai JiaoTong University, School of Medicine, Shanghai, China; and Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
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79
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Misconstrued versatility of Ganoderma lucidum: a key player in multi-targeted cellular signaling. Tumour Biol 2015; 37:2789-804. [DOI: 10.1007/s13277-015-4709-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Accepted: 12/20/2015] [Indexed: 01/11/2023] Open
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80
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Tang S, Chen T, Yang M, Wang L, Yu Z, Xie B, Qian C, Xu S, Li N, Cao X, Wang J. Extracellular calcium elicits feedforward regulation of the Toll-like receptor-triggered innate immune response. Cell Mol Immunol 2015; 14:180-191. [PMID: 26277896 DOI: 10.1038/cmi.2015.59] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2015] [Revised: 05/30/2015] [Accepted: 05/31/2015] [Indexed: 12/13/2022] Open
Abstract
Despite the expanding knowledge on feedback regulation of Toll-like receptor (TLR) signaling, the feedforward regulation of TLR signaling for the proper innate response to invading microbes is not fully understood. Here, we report that extracellular calcium can coordinate the activation of the small GTPases Ras and Ras-proximate-1 (Rap1) upon TLR stimulation which favors activation of macrophages through a feedforward mechanism. We show that different doses of TLR agonists can trigger different levels of cytokine production, which can be potentiated by extracellular calcium but are impaired by the chelating reagent ethylene glycol tetraacetic acid (EGTA) or by knockdown of stromal interaction molecule 1 (STIM1). Upon TLR engagement, GTP-bound Ras levels are increased and GTP-bound Rap1 is decreased, which can be reversed by EGTA-mediated removal of extracellular calcium. Furthermore, we demonstrate that Rap1 knockdown rescues the inhibitory effects of EGTA on the TLR-triggered innate response. Examination of the TLR signaling pathway reveals that extracellular calcium may regulate the TLR response via feedforward activation of the extracellular signal-regulated kinase signaling pathway. Our data suggest that an influx of extracellular calcium, mediated by STIM1-operated calcium channels, may transmit the information about the intensity of extracellular TLR stimuli to initiate innate responses at an appropriate level. Our study may provide mechanistic insight into the feedforward regulation of the TLR-triggered innate immune response.
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Affiliation(s)
- Songqing Tang
- Institute of Immunology, Zhejiang University School of Medicine, Hangzhou 310058, China.,National Key Laboratory of Medical Immunology & Institute of Immunology, Second Military Medical University, Shanghai 200433, China
| | - Taoyong Chen
- National Key Laboratory of Medical Immunology & Institute of Immunology, Second Military Medical University, Shanghai 200433, China
| | - Mingjin Yang
- National Key Laboratory of Medical Immunology & Institute of Immunology, Second Military Medical University, Shanghai 200433, China.,National Key Laboratory of Medical Molecular Biology & Department of Immunology, Chinese Academy of Medical Sciences, Beijing 100005, China
| | - Lei Wang
- National Key Laboratory of Medical Molecular Biology & Department of Immunology, Chinese Academy of Medical Sciences, Beijing 100005, China
| | - Zhou Yu
- Institute of Immunology, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Bin Xie
- Institute of Immunology, Zhejiang University School of Medicine, Hangzhou 310058, China.,National Key Laboratory of Medical Immunology & Institute of Immunology, Second Military Medical University, Shanghai 200433, China
| | - Cheng Qian
- National Key Laboratory of Medical Immunology & Institute of Immunology, Second Military Medical University, Shanghai 200433, China
| | - Sheng Xu
- National Key Laboratory of Medical Immunology & Institute of Immunology, Second Military Medical University, Shanghai 200433, China
| | - Nan Li
- National Key Laboratory of Medical Immunology & Institute of Immunology, Second Military Medical University, Shanghai 200433, China
| | - Xuetao Cao
- Institute of Immunology, Zhejiang University School of Medicine, Hangzhou 310058, China.,National Key Laboratory of Medical Immunology & Institute of Immunology, Second Military Medical University, Shanghai 200433, China.,National Key Laboratory of Medical Molecular Biology & Department of Immunology, Chinese Academy of Medical Sciences, Beijing 100005, China
| | - Jianli Wang
- Institute of Immunology, Zhejiang University School of Medicine, Hangzhou 310058, China
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81
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Zhou F, Dong C, Davis JE, Wu WH, Surrao K, Wu G. The mechanism and function of mitogen-activated protein kinase activation by ARF1. Cell Signal 2015; 27:2035-2044. [PMID: 26169956 DOI: 10.1016/j.cellsig.2015.06.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Accepted: 06/24/2015] [Indexed: 01/25/2023]
Abstract
Mitogen-activated protein kinases (MAPK) can be activated by a number of biochemical pathways through distinct signaling molecules. We have recently revealed a novel function for the Ras-like small GTPase ADP-ribosylation factor 1 (ARF1) in mediating the activation of Raf1-MEK-ERK1/2 pathway by G protein-coupled receptors [Dong C, Li C and Wu G (2011) J Biol Chem 286, 43,361-43,369]. Here, we have further defined the underlying mechanism and the possible function of ARF1-mediated MAPK pathway. We demonstrated that the blockage of ARF1 activation and the disruption of ARF1 localization to the Golgi by mutating Thr48, a highly conserved residue involved in the exchange of GDP for GTP, and the myristoylation site Gly2 abolished ARF1's ability to activate ERK1/2. In addition, treatment with Golgi structure disrupting agents markedly attenuated ARF1-mediated ERK1/2 activation. Furthermore, ARF1 significantly promoted cell proliferation. More interestingly, ARF1 activated 90kDa ribosomal S6 kinase 1 (RSK1) without influencing Elk-1 activation and ERK2 translocation to the nuclei. These data demonstrate that, once activated, ARF1 activates the MAPK pathway likely using the Golgi as a main platform, which in turn activates the cytoplasmic RSK1, leading to cell proliferation.
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Affiliation(s)
- Fuguo Zhou
- Department of Pharmacology and Experimental Therapeutics, Louisiana State University Health Sciences Center, 1901 Perdido St, New Orleans, LA 70112, United States
| | - Chunmin Dong
- Department of Pharmacology and Experimental Therapeutics, Louisiana State University Health Sciences Center, 1901 Perdido St, New Orleans, LA 70112, United States
| | - Jason E Davis
- Department of Pharmacology and Toxicology, Medical College of Georgia, Georgia Regents University, 1459 Laney Walker Blvd., Augusta, GA 30912, United States
| | - William H Wu
- Department of Pharmacology and Toxicology, Medical College of Georgia, Georgia Regents University, 1459 Laney Walker Blvd., Augusta, GA 30912, United States
| | - Kristen Surrao
- Department of Pharmacology and Toxicology, Medical College of Georgia, Georgia Regents University, 1459 Laney Walker Blvd., Augusta, GA 30912, United States
| | - Guangyu Wu
- Department of Pharmacology and Experimental Therapeutics, Louisiana State University Health Sciences Center, 1901 Perdido St, New Orleans, LA 70112, United States.,Department of Pharmacology and Toxicology, Medical College of Georgia, Georgia Regents University, 1459 Laney Walker Blvd., Augusta, GA 30912, United States
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82
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Ho JCS, Nadeem A, Rydström A, Puthia M, Svanborg C. Targeting of nucleotide-binding proteins by HAMLET--a conserved tumor cell death mechanism. Oncogene 2015; 35:897-907. [PMID: 26028028 DOI: 10.1038/onc.2015.144] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Revised: 03/24/2015] [Accepted: 03/29/2015] [Indexed: 12/20/2022]
Abstract
HAMLET (Human Alpha-lactalbumin Made LEthal to Tumor cells) kills tumor cells broadly suggesting that conserved survival pathways are perturbed. We now identify nucleotide-binding proteins as HAMLET binding partners, accounting for about 35% of all HAMLET targets in a protein microarray comprising 8000 human proteins. Target kinases were present in all branches of the Kinome tree, including 26 tyrosine kinases, 10 tyrosine kinase-like kinases, 13 homologs of yeast sterile kinases, 4 casein kinase 1 kinases, 15 containing PKA, PKG, PKC family kinases, 15 calcium/calmodulin-dependent protein kinase kinases and 13 kinases from CDK, MAPK, GSK3, CLK families. HAMLET acted as a broad kinase inhibitor in vitro, as defined in a screen of 347 wild-type, 93 mutant, 19 atypical and 17 lipid kinases. Inhibition of phosphorylation was also detected in extracts from HAMLET-treated lung carcinoma cells. In addition, HAMLET recognized 24 Ras family proteins and bound to Ras, RasL11B and Rap1B on the cytoplasmic face of the plasma membrane. Direct cellular interactions between HAMLET and activated Ras family members including Braf were confirmed by co-immunoprecipitation. As a consequence, oncogenic Ras and Braf activity was inhibited and HAMLET and Braf inhibitors synergistically increased tumor cell death in response to HAMLET. Unlike most small molecule kinase inhibitors, HAMLET showed selectivity for tumor cells in vitro and in vivo. The results identify nucleotide-binding proteins as HAMLET targets and suggest that dysregulation of the ATPase/kinase/GTPase machinery contributes to cell death, following the initial, selective recognition of HAMLET by tumor cells. The findings thus provide a molecular basis for the conserved tumoricidal effect of HAMLET, through dysregulation of kinases and oncogenic GTPases, to which tumor cells are addicted.
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Affiliation(s)
- J C S Ho
- Department of Microbiology, Immunology and Glycobiology (MIG), Institute of Laboratory Medicine, Lund University, Lund, Sweden
| | - A Nadeem
- Department of Microbiology, Immunology and Glycobiology (MIG), Institute of Laboratory Medicine, Lund University, Lund, Sweden
| | - A Rydström
- Department of Microbiology, Immunology and Glycobiology (MIG), Institute of Laboratory Medicine, Lund University, Lund, Sweden
| | - M Puthia
- Department of Microbiology, Immunology and Glycobiology (MIG), Institute of Laboratory Medicine, Lund University, Lund, Sweden
| | - C Svanborg
- Department of Microbiology, Immunology and Glycobiology (MIG), Institute of Laboratory Medicine, Lund University, Lund, Sweden
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83
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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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84
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Jang H, Abraham SJ, Chavan TS, Hitchinson B, Khavrutskii L, Tarasova NI, Nussinov R, Gaponenko V. Mechanisms of membrane binding of small GTPase K-Ras4B farnesylated hypervariable region. J Biol Chem 2015; 290:9465-77. [PMID: 25713064 PMCID: PMC4392252 DOI: 10.1074/jbc.m114.620724] [Citation(s) in RCA: 90] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Revised: 02/19/2015] [Indexed: 01/08/2023] Open
Abstract
K-Ras4B belongs to a family of small GTPases that regulates cell growth, differentiation and survival. K-ras is frequently mutated in cancer. K-Ras4B association with the plasma membrane through its farnesylated and positively charged C-terminal hypervariable region (HVR) is critical to its oncogenic function. However, the structural mechanisms of membrane association are not fully understood. Here, using confocal microscopy, surface plasmon resonance, and molecular dynamics simulations, we observed that K-Ras4B can be distributed in rigid and loosely packed membrane domains. Its membrane binding domain interaction with phospholipids is driven by membrane fluidity. The farnesyl group spontaneously inserts into the disordered lipid microdomains, whereas the rigid microdomains restrict the farnesyl group penetration. We speculate that the resulting farnesyl protrusion toward the cell interior allows oligomerization of the K-Ras4B membrane binding domain in rigid microdomains. Unlike other Ras isoforms, K-Ras4B HVR contains a single farnesyl modification and positively charged polylysine sequence. The high positive charge not only modulates specific HVR binding to anionic phospholipids but farnesyl membrane orientation. Phosphorylation of Ser-181 prohibits spontaneous farnesyl membrane insertion. The mechanism illuminates the roles of HVR modifications in K-Ras4B targeting microdomains of the plasma membrane and suggests an additional function for HVR in regulation of Ras signaling.
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Affiliation(s)
- Hyunbum Jang
- From the Basic Science Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research and Cancer and Inflammation Program, NCI-Frederick, National Institutes of Health, Frederick, Maryland 21702
| | - Sherwin J Abraham
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, California 94305, Departments of Biochemistry and Molecular Genetics and
| | - Tanmay S Chavan
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, California 94305, Medicinal Chemistry, University of Illinois, Chicago, Illinois 60607, and
| | | | - Lyuba Khavrutskii
- From the Basic Science Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research and Cancer and Inflammation Program, NCI-Frederick, National Institutes of Health, Frederick, Maryland 21702
| | - Nadya I Tarasova
- Cancer and Inflammation Program, NCI-Frederick, National Institutes of Health, Frederick, Maryland 21702,
| | - Ruth Nussinov
- From the Basic Science Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research and Cancer and Inflammation Program, NCI-Frederick, National Institutes of Health, Frederick, Maryland 21702, Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Vadim Gaponenko
- Departments of Biochemistry and Molecular Genetics and Medicinal Chemistry, University of Illinois, Chicago, Illinois 60607, and
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85
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Massi D, Simi L, Sensi E, Baroni G, Xue G, Scatena C, Caldarella A, Pinzani P, Fontanini G, Carobbio A, Urso C, Mandalà M. Immunohistochemistry is highly sensitive and specific for the detection of NRASQ61R mutation in melanoma. Mod Pathol 2015; 28:487-97. [PMID: 25341653 DOI: 10.1038/modpathol.2014.137] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Revised: 08/25/2014] [Accepted: 09/01/2014] [Indexed: 12/30/2022]
Abstract
Testing for NRAS is now integral part in the assessment of metastatic melanoma patients because there is evidence that NRAS-mutated patients may be sensitive to MEK inhibitors, and RAS mutation is a common mechanism of acquired resistance during treatment with BRAF inhibitors. This study evaluated the sensitivity and specificity of immunohistochemical analysis using an N-Ras (Q61R) antibody to detect the presence of the NRASQ61R mutation in melanoma patients. A total of 98 primary cutaneous melanomas that have undergone examination of NRAS mutation were retrieved from a multicentric database. Formalin-fixed and paraffin-embedded melanoma tissues were analyzed for BRAF and NRAS mutations by independent, blinded observers using both conventional DNA molecular techniques and immunohistochemistry with the novel anti-human N-Ras (Q61R) monoclonal antibody (clone SP174). The antibody showed a sensitivity of 100% (14/14) and a specificity of 100% (83/83) for detecting the presence of an NRASQ61R mutation. Of the NRAS-mutated cases, none of the non-Q61R cases stained positive with the antibody (0/7). There were three cases with discordant NRAS mutational results. Additional molecular analysis confirmed the immunohistochemically obtained NRAS result in all cases, suggesting that a multiple analytical approach can be required to reach the correct sample classification. The reported immunohistochemical method is an accurate, rapid, and cost-effective method for detecting NRASQ61R mutation in melanoma patients, and represents a valuable supplement to traditional mutation testing. If validated in further studies, genetic testing would only be required for immunohistochemistry-negative patients to detect non-Q61R mutations.
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Affiliation(s)
- Daniela Massi
- Division of Pathological Anatomy, Department of Surgery and Translational Medicine, University of Florence, Florence, Italy
| | - Lisa Simi
- Clinical Biochemistry Unit, Department of Biomedical, Experimental and Clinical Sciences, University of Florence, Florence, Italy
| | - Elisa Sensi
- Laboratory of Molecular Pathology, UO Pathological Anatomy III, Pisa, Italy
| | - Gianna Baroni
- Division of Pathological Anatomy, Department of Surgery and Translational Medicine, University of Florence, Florence, Italy
| | - Gongda Xue
- Unit of Mechanisms of Cancer, Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Cristian Scatena
- Division of Pathological Anatomy, Department of Surgery and Translational Medicine, University of Florence, Florence, Italy
| | - Adele Caldarella
- Clinical and Descriptive Epidemiology Unit, Institute for Study and Cancer Prevention (ISPO), Florence, Italy
| | - Pamela Pinzani
- Clinical Biochemistry Unit, Department of Biomedical, Experimental and Clinical Sciences, University of Florence, Florence, Italy
| | | | | | - Carmelo Urso
- Dermatopathology Section, SM Annunziata Hospital, Florence, Italy
| | - Mario Mandalà
- Unit of Medical Oncology, Division of Medical Oncology, Department of Oncology and Haematology, Papa Giovanni XXIII Hospital, Bergamo, Italy
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86
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Li J, Chai QY, Zhang Y, Li BX, Wang J, Qiu XB, Liu CH. Mycobacterium tuberculosis Mce3E suppresses host innate immune responses by targeting ERK1/2 signaling. THE JOURNAL OF IMMUNOLOGY 2015; 194:3756-67. [PMID: 25780035 DOI: 10.4049/jimmunol.1402679] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Accepted: 02/12/2015] [Indexed: 11/19/2022]
Abstract
Crucial to the pathogenesis of the tuberculosis (TB)-causing pathogen Mycobacterium tuberculosis is its ability to subvert host immune defenses to promote its intracellular survival. The mammalian cell entry protein 3E (Mce3E), located in the region of difference 15 of the M. tuberculosis genome and absent in Mycobacterium bovis bacillus Calmette-Guérin, has an essential role in facilitating the internalization of mammalian cells by mycobacteria. However, relatively little is known about the role of Mce3E in modulation of host innate immune responses. In this study, we demonstrate that Mce3E inhibits the activation of the ERK1/2 signaling pathway, leading to the suppression of Tnf and Il6 expression, and the promotion of mycobacterial survival within macrophages. Mce3E interacts and colocalizes with ERK1/2 at the endoplasmic reticulum in a DEF motif (an ERK-docking motif)-dependent manner, relocates ERK1/2 from cytoplasm to the endoplasmic reticulum, and finally reduces the association of ERK1/2 with MEK1 and blocks the nuclear translocation of phospho-ERK1/2. A DEF motif mutant form of Mce3E (F294A) loses its ability to suppress Tnf and Il6 expression and to promote intracellular survival of mycobacteria. Inhibition of the ERK1/2 pathway in macrophages using U0126, a specific inhibitor of the ERK pathway, also leads to the suppressed Tnf and Il6 expression and the enhanced intracellular survival of mycobacteria. Taken together, these results suggest that M. tuberculosis Mce3E exploits the ERK1/2 signaling pathway to suppress host innate immune responses, providing a potential Mce3E-ERK1/2 interface-based drug target against M. tuberculosis.
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Affiliation(s)
- Jie Li
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; and
| | - Qi-Yao Chai
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; and
| | - Yong Zhang
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; and
| | - Bing-Xi Li
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; and
| | - Jing Wang
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; and
| | - Xiao-Bo Qiu
- Department of Cell Biology, Ministry of Education Key Laboratory of Cell Proliferation and Regulation Biology, College of Life Sciences, Beijing Normal University, Beijing 100875, China
| | - Cui Hua Liu
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; and
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87
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Wang X, Batty KM, Crowe PJ, Goldstein D, Yang JL. The Potential of panHER Inhibition in Cancer. Front Oncol 2015; 5:2. [PMID: 25674538 PMCID: PMC4309158 DOI: 10.3389/fonc.2015.00002] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Accepted: 01/07/2015] [Indexed: 12/22/2022] Open
Abstract
Purpose: Hyper-activation of the HER (erbB) family receptors, HER 1-4, leads to up-regulation of the three vital signaling pathways: mitogen activated protein kinase, phosphoinositide 3-kinase/AKT, and Janus kinase/signal transducer and activator of transcription pathways. Blocking HER1/EGFR has a limited anticancer effect due to either secondary mutation e.g., T790M or by-pass signaling of other HER members. The emergence of an anti-panHER approach to blockade of these pathways as a cancer treatment may provide a solution to this resistance. This review aimed to provide an overview of the HER signaling pathways and their involvement in tumor progression and examine the current progress in panHER inhibition. Methods: Recent literature associated with HER signaling pathways and panHER inhibition was reviewed through PubMed and Medline database, followed by critical comparison and analysis. Results: Pre-clinical studies and clinical trials of panHER inhibitors show promising results, and the potential to improve patient outcomes in solid cancers. Conclusion: The use of panHER inhibitors in cancers with HER-family hyper-activation, such as other epithelial cancers and sarcoma, is a new direction to research and has potential in clinical cancer therapy in the future.
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Affiliation(s)
- Xiaochun Wang
- Sarcoma Nano-Oncology Group, Adult Cancer Program, Lowy Cancer Research Centre, Prince of Wales Clinical School, University of New South Wales (UNSW) , Sydney, NSW , Australia ; Department of Surgery, Prince of Wales Clinical School, University of New South Wales (UNSW) , Sydney, NSW , Australia
| | - Kathleen M Batty
- Sarcoma Nano-Oncology Group, Adult Cancer Program, Lowy Cancer Research Centre, Prince of Wales Clinical School, University of New South Wales (UNSW) , Sydney, NSW , Australia ; Department of Surgery, Prince of Wales Clinical School, University of New South Wales (UNSW) , Sydney, NSW , Australia
| | - Philip J Crowe
- Sarcoma Nano-Oncology Group, Adult Cancer Program, Lowy Cancer Research Centre, Prince of Wales Clinical School, University of New South Wales (UNSW) , Sydney, NSW , Australia ; Department of Surgery, Prince of Wales Clinical School, University of New South Wales (UNSW) , Sydney, NSW , Australia
| | - David Goldstein
- Sarcoma Nano-Oncology Group, Adult Cancer Program, Lowy Cancer Research Centre, Prince of Wales Clinical School, University of New South Wales (UNSW) , Sydney, NSW , Australia ; Department of Medical Oncology, Prince of Wales Clinical School, University of New South Wales (UNSW) , Sydney, NSW , Australia
| | - Jia-Lin Yang
- Sarcoma Nano-Oncology Group, Adult Cancer Program, Lowy Cancer Research Centre, Prince of Wales Clinical School, University of New South Wales (UNSW) , Sydney, NSW , Australia ; Department of Surgery, Prince of Wales Clinical School, University of New South Wales (UNSW) , Sydney, NSW , Australia
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88
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K-Ras4A splice variant is widely expressed in cancer and uses a hybrid membrane-targeting motif. Proc Natl Acad Sci U S A 2015; 112:779-84. [PMID: 25561545 DOI: 10.1073/pnas.1412811112] [Citation(s) in RCA: 167] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The two products of the KRAS locus, K-Ras4A and K-Ras4B, are encoded by alternative fourth exons and therefore, possess distinct membrane-targeting sequences. The common activating mutations occur in exons 1 or 2 and therefore, render both splice variants oncogenic. K-Ras4A has been understudied, because it has been considered a minor splice variant. By priming off of the splice junction, we developed a quantitative RT-PCR assay for K-Ras4A and K-Ras4B message capable of measuring absolute amounts of the two transcripts. We found that K-Ras4A was widely expressed in 30 of 30 human cancer cell lines and amounts equal to K-Ras4B in 17 human colorectal tumors. Using splice variant-specific antibodies, we detected K-Ras4A protein in several tumor cell lines at a level equal to or greater than that of K-Ras4B. In addition to the CAAX motif, the C terminus of K-Ras4A contains a site of palmitoylation as well as a bipartite polybasic region. Although both were required for maximal efficiency, each of these could independently deliver K-Ras4A to the plasma membrane. Thus, among four Ras proteins, K-Ras4A is unique in possessing a dual membrane-targeting motif. We also found that, unlike K-Ras4B, K-Ras4A does not bind to the cytosolic chaperone δ-subunit of cGMP phosphodiesterase type 6 (PDE6δ). We conclude that efforts to develop anti-K-Ras drugs that interfere with membrane trafficking will have to take into account the distinct modes of targeting of the two K-Ras splice variants.
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89
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Molecular mechanisms and functional implications of polarized actin remodeling at the T cell immunological synapse. Cell Mol Life Sci 2014; 72:537-556. [PMID: 25355055 DOI: 10.1007/s00018-014-1760-7] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2014] [Revised: 09/22/2014] [Accepted: 10/13/2014] [Indexed: 02/05/2023]
Abstract
Transient,specialized cell-cell interactions play a central role in leukocyte function by enabling specific intercellular communication in the context of a highly dynamic systems level response. The dramatic structural changes required for the formation of these contacts are driven by rapid and precise cytoskeletal remodeling events. In recent years, the immunological synapse that forms between a T lymphocyte and its antigen-presenting target cell has emerged as an important model system for understanding immune cell interactions. In this review, we discuss how regulators of the cortical actin cytoskeleton control synaptic architecture and in this way specify T cell function.
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90
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Zhou Y, Hancock JF. Ras nanoclusters: Versatile lipid-based signaling platforms. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2014; 1853:841-9. [PMID: 25234412 DOI: 10.1016/j.bbamcr.2014.09.008] [Citation(s) in RCA: 174] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2014] [Revised: 09/05/2014] [Accepted: 09/08/2014] [Indexed: 12/31/2022]
Abstract
Ras proteins assemble into transient nanoclusters on the plasma membrane. Nanoclusters are the sites of Ras effector recruitment and activation and are therefore essential for signal transmission. The dynamics of nanocluster formation and disassembly result in interesting emergent properties including high-fidelity signal transmission. More recently the lipid structure of Ras nanoclusters has been reported and shown to contribute to isoform-specific Ras signaling. In addition specific lipids play critical roles in mediating the formation, stability and dynamics of Ras nanoclusters. In consequence the spatiotemporal organization of these lipids has emerged as important and novel regulators of Ras function. This article is part of a Special Issue entitled: Nanoscale membrane organisation and signalling.
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Affiliation(s)
- Yong Zhou
- Department of Integrative Biology and Pharmacology, University of Texas Medical School, Houston, TX 77030, USA.
| | - John F Hancock
- Department of Integrative Biology and Pharmacology, University of Texas Medical School, Houston, TX 77030, USA.
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91
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Torres LC, Soares DCDQ, Kulikowski LD, Franco JF, Kim CA. NK and B cell deficiency in a MPS type II family with novel mutation in the IDS gene. Clin Immunol 2014; 154:100-4. [PMID: 25038527 DOI: 10.1016/j.clim.2014.07.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2013] [Revised: 06/09/2014] [Accepted: 07/04/2014] [Indexed: 11/16/2022]
Abstract
The mucopolysaccharidoses (MPSs) are a group of rare, inherited lysosomal storage disorders that are clinically characterized by abnormalities in multiple organ systems and reduced life expectancy. Whereas the lysosome is essential to the functioning of the immune system, some authors suggest that the MPS patients have abnormalities in the immune system similar to the patients with primary immunodeficiency. In this study, we evaluated 8 male MPS type II patients of the same family with novel mutation in the IDS gene. We found in this MPS family a quantitative deficiency of NK and B cells with normal values of IgG, IgM and IgA serum antibodies and normal response to polysaccharide antigens. Interestingly, abnormalities found in these patients were not observed in other MPS patients, suggesting that the type of mutation found in the IDS gene can be implicated in the immunodeficiency.
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Affiliation(s)
- Leuridan Cavalcante Torres
- Translational Research Laboratory Prof. C. A. Hart, Instituto de Medicina Integral Prof. Fernando Figueira (IMIP), Recife, Brazil; Medical Investigation Laboratory (LIM 36), Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo (USP), São Paulo, Brazil.
| | - Diogo Cordeiro de Queiroz Soares
- Translational Research Laboratory Prof. C. A. Hart, Instituto de Medicina Integral Prof. Fernando Figueira (IMIP), Recife, Brazil; Medical Genetics Unit, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo (USP), São Paulo, Brazil
| | - Leslie Domenici Kulikowski
- Department of Pathology, Citogenomics Laboratory (LIM 03), Universidade de São Paulo (USP), São Paulo, Brazil
| | - Jose Francisco Franco
- Medical Genetics Unit, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo (USP), São Paulo, Brazil
| | - Chong Ae Kim
- Medical Genetics Unit, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo (USP), São Paulo, Brazil
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92
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Iversen L, Tu HL, Lin WC, Christensen SM, Abel SM, Iwig J, Wu HJ, Gureasko J, Rhodes C, Petit RS, Hansen SD, Thill P, Yu CH, Stamou D, Chakraborty AK, Kuriyan J, Groves JT. Molecular kinetics. Ras activation by SOS: allosteric regulation by altered fluctuation dynamics. Science 2014; 345:50-4. [PMID: 24994643 DOI: 10.1126/science.1250373] [Citation(s) in RCA: 103] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Activation of the small guanosine triphosphatase H-Ras by the exchange factor Son of Sevenless (SOS) is an important hub for signal transduction. Multiple layers of regulation, through protein and membrane interactions, govern activity of SOS. We characterized the specific activity of individual SOS molecules catalyzing nucleotide exchange in H-Ras. Single-molecule kinetic traces revealed that SOS samples a broad distribution of turnover rates through stochastic fluctuations between distinct, long-lived (more than 100 seconds), functional states. The expected allosteric activation of SOS by Ras-guanosine triphosphate (GTP) was conspicuously absent in the mean rate. However, fluctuations into highly active states were modulated by Ras-GTP. This reveals a mechanism in which functional output may be determined by the dynamical spectrum of rates sampled by a small number of enzymes, rather than the ensemble average.
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Affiliation(s)
- Lars Iversen
- Howard Hughes Medical Institute, Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Hsiung-Lin Tu
- Howard Hughes Medical Institute, Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Wan-Chen Lin
- Howard Hughes Medical Institute, Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Sune M Christensen
- Howard Hughes Medical Institute, Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Steven M Abel
- Department of Chemical Engineering, Massachusetts Institute of Technology (MIT), Cambridge, MA 02139, USA
| | - Jeff Iwig
- Howard Hughes Medical Institute, Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Hung-Jen Wu
- Howard Hughes Medical Institute, Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Jodi Gureasko
- Howard Hughes Medical Institute, Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Christopher Rhodes
- Department of Mechanical Engineering, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Rebecca S Petit
- Howard Hughes Medical Institute, Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Scott D Hansen
- Howard Hughes Medical Institute, Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Peter Thill
- Department of Chemistry, MIT, Cambridge, MA 02139, USA
| | - Cheng-Han Yu
- Mechanobiology Institute, National University of Singapore, Singapore
| | - Dimitrios Stamou
- Department of Chemistry and Nano-Science Center, University of Copenhagen, Copenhagen, Denmark
| | - Arup K Chakraborty
- Department of Chemical Engineering, Massachusetts Institute of Technology (MIT), Cambridge, MA 02139, USA. Department of Chemistry, MIT, Cambridge, MA 02139, USA. Department of Biological Engineering, MIT, Cambridge, MA 02139, USA. Ragon Institute of Massachusetts General Hospital, MIT, and Harvard, Cambridge, MA 02139, USA. Department of Physics, MIT, Cambridge, MA 02139, USA. Institute for Medical Engineering and Science, MIT, Cambridge, MA 02139, USA
| | - John Kuriyan
- Howard Hughes Medical Institute, Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA. Howard Hughes Medical Institute, Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA. Physical Biosciences and Materials Sciences Divisions, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Jay T Groves
- Howard Hughes Medical Institute, Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA. Mechanobiology Institute, National University of Singapore, Singapore. Physical Biosciences and Materials Sciences Divisions, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA. Berkeley Education Alliance for Research in Singapore, 1 Create Way, CREATE tower level 11, University Town, Singapore 138602.
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93
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Mandalà M, Merelli B, Massi D. Nras in melanoma: targeting the undruggable target. Crit Rev Oncol Hematol 2014; 92:107-22. [PMID: 24985059 DOI: 10.1016/j.critrevonc.2014.05.005] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2014] [Revised: 05/01/2014] [Accepted: 05/09/2014] [Indexed: 12/30/2022] Open
Abstract
RAS belongs to the guanosine 5'-triphosphate (GTP)-binding proteins' family, and oncogenic mutations in codons 12, 13, or 61 of RAS family occur in approximately one third of all human cancers with N-RAS mutations found in about 15-20% of melanomas. The importance of RAS signaling as a potential target in cancer is emphasized not only by the prevalence of RAS mutations, but also by the high number of RAS activators and effectors identified in mammalian cells that places the RAS proteins at the crossroads of several, important signaling networks. Ras proteins are crucial crossroads of signaling pathways that link the activation of cell surface receptors with a wide variety of cellular processes leading to the control of proliferation, apoptosis and differentiation. Furthermore, oncogenic ras proteins interfere with metabolism of tumor cells, microenvironment's remodeling, evasion of the immune response, and finally contributes to the metastatic process. After 40 years of basic, translational and clinical research, much is now known about the molecular mechanisms by which these monomeric guanosine triphosphatase-binding proteins promote cellular malignancy, and it is clear that they regulate signaling pathways involved in the control of cell proliferation, survival, and invasiveness. In this review we summarize the biological role of RAS in cancer by focusing our attention on the biological rational and strategies to target RAS in melanoma.
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Affiliation(s)
- Mario Mandalà
- Unit of Medical Oncology, Department of Oncology and Hematology, Papa Giovanni XXIII Hospital, Bergamo, Italy.
| | - Barbara Merelli
- Unit of Medical Oncology, Department of Oncology and Hematology, Papa Giovanni XXIII Hospital, Bergamo, Italy
| | - Daniela Massi
- Division of Pathological Anatomy, Department of Surgery and Translational Medicine, University of Florence, Italy
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94
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Vasan N, Boyer JL, Herbst RS. A RAS renaissance: emerging targeted therapies for KRAS-mutated non-small cell lung cancer. Clin Cancer Res 2014; 20:3921-30. [PMID: 24893629 DOI: 10.1158/1078-0432.ccr-13-1762] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Of the numerous oncogenes implicated in human cancer, the most common and perhaps the most elusive to target pharmacologically is RAS. Since the discovery of RAS in the 1960s, numerous studies have elucidated the mechanism of activity, regulation, and intracellular trafficking of the RAS gene products, and of its regulatory pathways. These pathways yielded druggable targets, such as farnesyltransferase, during the 1980s to 1990s. Unfortunately, early clinical trials investigating farnesyltransferase inhibitors yielded disappointing results, and subsequent interest by pharmaceutical companies in targeting RAS waned. However, recent advances including the identification of novel regulatory enzymes (e.g., Rce1, Icmt, Pdeδ), siRNA-based synthetic lethality screens, and fragment-based small-molecule screens, have resulted in a "Ras renaissance," signified by new Ras and Ras pathway-targeted therapies that have led to new clinical trials of patients with Ras-driven cancers. This review gives an overview of KRas signaling pathways with an emphasis on novel targets and targeted therapies, using non-small cell lung cancer as a case example.
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Affiliation(s)
- Neil Vasan
- Department of Internal Medicine, Massachusetts General Hospital, Boston, Massachusetts
| | - Julie L Boyer
- The Sandra and Edward Meyer Cancer Center at Weill Cornell Medical College, New York, New York; and
| | - Roy S Herbst
- Yale Cancer Center and Smilow Cancer Hospital at Yale-New Haven, New Haven, Connecticut
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95
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Guan Y, Meng X, Khanna R, LaMontagne E, Liu Y, Zhang S. Phosphorylation of a WRKY transcription factor by MAPKs is required for pollen development and function in Arabidopsis. PLoS Genet 2014; 10:e1004384. [PMID: 24830428 PMCID: PMC4022456 DOI: 10.1371/journal.pgen.1004384] [Citation(s) in RCA: 115] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2013] [Accepted: 04/01/2014] [Indexed: 01/28/2023] Open
Abstract
Plant male gametogenesis involves complex and dynamic changes in gene expression. At present, little is known about the transcription factors involved in this process and how their activities are regulated. Here, we show that a pollen-specific transcription factor, WRKY34, and its close homolog, WRKY2, are required for male gametogenesis in Arabidopsis thaliana. When overexpressed using LAT52, a strong pollen-specific promoter, epitope-tagged WRKY34 is temporally phosphorylated by MPK3 and MPK6, two mitogen-activated protein kinases (MAPKs, or MPKs), at early stages in pollen development. During pollen maturation, WRKY34 is dephosphorylated and degraded. Native promoter-driven WRKY34-YFP fusion also follows the same expression pattern at the protein level. WRKY34 functions redundantly with WRKY2 in pollen development, germination, and pollen tube growth. Loss of MPK3/MPK6 phosphorylation sites in WRKY34 compromises the function of WRKY34 in vivo. Epistasis interaction analysis confirmed that MPK6 belongs to the same genetic pathway of WRKY34 and WRKY2. Our study demonstrates the importance of temporal post-translational regulation of WRKY transcription factors in the control of developmental phase transitions in plants. Pollen development, or male gametogenesis, is a process by which a haploid uninucleate microspore undergoes cell division and specification to form a mature pollen grain containing two sperm cells. The highly defined cell linage makes pollen development an ideal model to understand the regulation of plant cellular development. Pollen development has multiple phases and involves dynamic changes in gene expression, which highlights the importance of transcription factors and their regulatory pathway(s). In this report, we demonstrate that WRKY34 and WRKY2, two closely related WRKY transcription factors in Arabidopsis, play important roles in pollen development. WRKY34 is phosphorylated by MPK3/MPK6, two functionally redundant mitogen-activated protein kinases (MAPKs or MPKs), at early stages in pollen development. Utilizing a combination of genetic, biochemical, and cytological tools, we determined that this MAPK-WRKY signaling module functions at the early stage of pollen development. Loss of function of this pathway reduces pollen viability, and the surviving pollen has poor germination and reduced pollen tube growth, all of which reduce the transmission rate of the mutant pollen. This study discovers a novel stage-specific signaling pathway in pollen development.
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Affiliation(s)
- Yuefeng Guan
- Division of Biochemistry, Interdisciplinary Plant Group, and Bond Life Sciences Center, University of Missouri, Columbia, Missouri, United States of America
- Shanghai Center for Plant Stress Biology, Chinese Academy of Sciences, Shanghai, China
| | - Xiangzong Meng
- Division of Biochemistry, Interdisciplinary Plant Group, and Bond Life Sciences Center, University of Missouri, Columbia, Missouri, United States of America
| | - Reshma Khanna
- Division of Biochemistry, Interdisciplinary Plant Group, and Bond Life Sciences Center, University of Missouri, Columbia, Missouri, United States of America
| | - Erica LaMontagne
- Division of Biochemistry, Interdisciplinary Plant Group, and Bond Life Sciences Center, University of Missouri, Columbia, Missouri, United States of America
| | - Yidong Liu
- Division of Biochemistry, Interdisciplinary Plant Group, and Bond Life Sciences Center, University of Missouri, Columbia, Missouri, United States of America
| | - Shuqun Zhang
- Division of Biochemistry, Interdisciplinary Plant Group, and Bond Life Sciences Center, University of Missouri, Columbia, Missouri, United States of America
- * E-mail:
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96
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Aizman E, Blacher E, Ben-Moshe O, Kogan T, Kloog Y, Mor A. Therapeutic effect of farnesylthiosalicylic acid on adjuvant-induced arthritis through suppressed release of inflammatory cytokines. Clin Exp Immunol 2014; 175:458-67. [PMID: 24215151 DOI: 10.1111/cei.12235] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/05/2013] [Indexed: 01/23/2023] Open
Abstract
Rheumatoid arthritis (RA) is an autoimmune disease characterized by pronounced inflammation and leucocyte infiltration in affected joints. Despite significant therapeutic advances, a new targeted approach is needed. Our objective in this work was to investigate the anti-inflammatory effects of the Ras inhibitor farnesylthiosalicylic acid (FTS) on adjuvant-induced arthritis (AIA) in rats, an experimental model for RA. Following AIA induction in Lewis rats by intradermal injection of heat-killed Mycobacterium tuberculosis, rats were treated with either FTS or dexamethasone and assessed daily for paw swelling. Joints were imaged by magnetic resonance imaging and computerized tomography and analysed histologically. The anti-inflammatory effect of FTS was assessed by serum assay of multiple cytokines. After adjuvant injection rats demonstrated paw swelling, leucocyte infiltration, cytokine secretion and activation of Ras-effector pathways. Upon FTS treatment these changes reverted almost to normal. Histopathological analysis revealed that the synovial hyperplasia and leucocyte infiltration observed in the arthritic rats were alleviated by FTS. Periarticular bony erosions were averted. Efficacy of FTS treatment was also demonstrated by inhibition of CD4(+) and CD8(+) T cell proliferation and of interferon (IFN)-γ, tumour necrosis factor (TNF)-α, interleukin (IL)-6 and IL-17 release. The Ras effectors PI3K, protein kinase B (AKT), p38, and extracellular-regulated kinase (ERK) were significantly attenuated and forkhead box protein 3 (FoxP3) transcription factor, a marker of regulatory T cells, was significantly increased. Thus, FTS possesses significant anti-inflammatory and anti-arthritic properties and accordingly shows promise as a potential therapeutic agent for RA. Its effects are apparently mediated, at least in part, by a decrease in proinflammatory cytokines.
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Affiliation(s)
- E Aizman
- Department of Neurobiology, George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv, Israel
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97
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Guzmán C, Šolman M, Ligabue A, Blaževitš O, Andrade DM, Reymond L, Eggeling C, Abankwa D. The efficacy of Raf kinase recruitment to the GTPase H-ras depends on H-ras membrane conformer-specific nanoclustering. J Biol Chem 2014; 289:9519-33. [PMID: 24569991 DOI: 10.1074/jbc.m113.537001] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Solution structures and biochemical data have provided a wealth of mechanistic insight into Ras GTPases. However, information on how much the membrane organization of these lipid-modified proteins impacts on their signaling is still scarce. Ras proteins are organized into membrane nanoclusters, which are necessary for Ras-MAPK signaling. Using quantitative conventional and super-resolution fluorescence methods, as well as mathematical modeling, we investigated nanoclustering of H-ras helix α4 and hypervariable region mutants that have different bona fide conformations on the membrane. By following the emergence of conformer-specific nanoclusters in the plasma membrane of mammalian cells, we found that conformers impart distinct nanoclustering responses depending on the cytoplasmic levels of the nanocluster scaffold galectin-1. Computational modeling revealed that complexes containing H-ras conformers and galectin-1 affect both the number and lifetime of nanoclusters and thus determine the specific Raf effector recruitment. Our results show that mutations in Ras can affect its nanoclustering response and thus allosterically effector recruitment and downstream signaling. We postulate that cancer- and developmental disease-linked mutations that are associated with the Ras membrane conformation may exhibit so far unrecognized Ras nanoclustering and therefore signaling alterations.
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Affiliation(s)
- Camilo Guzmán
- From the Turku Centre for Biotechnology, Åbo Akademi University, Tykistökatu 6B, 20520 Turku, Finland
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98
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H-Ras forms dimers on membrane surfaces via a protein-protein interface. Proc Natl Acad Sci U S A 2014; 111:2996-3001. [PMID: 24516166 DOI: 10.1073/pnas.1321155111] [Citation(s) in RCA: 124] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The lipid-anchored small GTPase Ras is an important signaling node in mammalian cells. A number of observations suggest that Ras is laterally organized within the cell membrane, and this may play a regulatory role in its activation. Lipid anchors composed of palmitoyl and farnesyl moieties in H-, N-, and K-Ras are widely suspected to be responsible for guiding protein organization in membranes. Here, we report that H-Ras forms a dimer on membrane surfaces through a protein-protein binding interface. A Y64A point mutation in the switch II region, known to prevent Son of sevenless and PI3K effector interactions, abolishes dimer formation. This suggests that the switch II region, near the nucleotide binding cleft, is either part of, or allosterically coupled to, the dimer interface. By tethering H-Ras to bilayers via a membrane-miscible lipid tail, we show that dimer formation is mediated by protein interactions and does not require lipid anchor clustering. We quantitatively characterize H-Ras dimerization in supported membranes using a combination of fluorescence correlation spectroscopy, photon counting histogram analysis, time-resolved fluorescence anisotropy, single-molecule tracking, and step photobleaching analysis. The 2D dimerization Kd is measured to be ∼1 × 10(3) molecules/µm(2), and no higher-order oligomers were observed. Dimerization only occurs on the membrane surface; H-Ras is strictly monomeric at comparable densities in solution. Analysis of a number of H-Ras constructs, including key changes to the lipidation pattern of the hypervariable region, suggest that dimerization is a general property of native H-Ras on membrane surfaces.
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99
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Muñoz S, Manjón E, García P, Sunnerhagen P, Sánchez Y. The checkpoint-dependent nuclear accumulation of Rho1p exchange factor Rgf1p is important for tolerance to chronic replication stress. Mol Biol Cell 2014; 25:1137-50. [PMID: 24478458 PMCID: PMC3967976 DOI: 10.1091/mbc.e13-11-0689] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Guanine nucleotide exchange factors control many aspects of cell morphogenesis by turning on Rho-GTPases. The fission yeast exchange factor Rgf1p (Rho gef1) specifically regulates Rho1p during polarized growth and localizes to cortical sites. Here we report that Rgf1p is relocalized to the cell nucleus during the stalled replication caused by hydroxyurea (HU). Import to the nucleus is mediated by a nuclear localization sequence at the N-terminus of Rgf1p, whereas release into the cytoplasm requires two leucine-rich nuclear export sequences at the C-terminus. Moreover, Rgf1p nuclear accumulation during replication arrest depends on the 14-3-3 chaperone Rad24p and the DNA replication checkpoint kinase Cds1p. Both proteins control the nuclear accumulation of Rgf1p by inhibition of its nuclear export. A mutant, Rgf1p-9A, that substitutes nine serine potential phosphorylation Cds1p sites for alanine fails to accumulate in the nucleus in response to replication stress, and this correlates with a severe defect in survival in the presence of HU. In conclusion, we propose that the regulation of Rgf1p could be part of the mechanism by which Cds1p and Rad24p promote survival in the presence of chronic replication stress. It will be of general interest to understand whether the same is true for homologues of Rgf1p in budding yeast and higher eukaryotes.
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Affiliation(s)
- Sofía Muñoz
- Instituto de Biología Funcional y Genómica and Departamento de Microbiología y Genética, CSIC/Universidad de Salamanca, 37008 Salamanca, Spain Department of Chemistry and Molecular Biology, Lundberg Laboratory, University of Gothenburg, S-405 30 Gothenburg, Sweden
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100
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Le Page A, Fortin C, Garneau H, Allard N, Tsvetkova K, Tan CTY, Larbi A, Dupuis G, Fülöp T. Downregulation of inhibitory SRC homology 2 domain-containing phosphatase-1 (SHP-1) leads to recovery of T cell responses in elderly. Cell Commun Signal 2014; 12:2. [PMID: 24405902 PMCID: PMC3896791 DOI: 10.1186/1478-811x-12-2] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2013] [Accepted: 01/04/2014] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND Immune responses are generally impaired in aged mammals. T cells have been extensively studied in this context due to the initial discovery of their reduced proliferative capacity with aging. The decreased responses involve altered signaling events associated with the early steps of T cell activation. The underlying causes of these changes are not fully understood but point to alterations in assembly of the machinery for T cell activation. Here, we have tested the hypothesis that the T cell pool in elderly subjects displayed reduced functional capacities due to altered negative feedback mechanisms that participate in the regulation of the early steps of T cell activation. Such conditions tip the immune balance in favor of altered T cell activation and a related decreased response in aging. RESULTS We present evidence that the tyrosine phosphatase SHP-1, a key regulator of T cell signal transduction machinery is, at least in part, responsible for the impaired T cell activation in aging. We used tyrosine-specific mAbs and Western blot analysis to show that a deregulation of the Csk/PAG loop in activated T cells from elderly individuals favored the inactive form of tyrosine-phosphorylated Lck (Y505). Confocal microscopy analysis revealed that the dynamic movements of these regulatory proteins in lipid raft microdomains was altered in T cells of aged individuals. Enzymic assays showed that SHP-1 activity was upregulated in T cells of aged donors, in contrast to young subjects. Pharmacological inhibition of SHP-1 resulted in recovery of TCR/CD28-dependent lymphocyte proliferation and IL-2 production of aged individuals to levels approaching those of young donors. Significant differences in the active (Y394) and inactive (Y505) phosphorylation sites of Lck in response to T cell activation were observed in elderly donors as compared to young subjects, independently of CD45 isoform expression. CONCLUSIONS Our data suggest that the role of SHP-1 in T cell activation extends to its increased effect in negative feedback in aging. Modulation of SHP-1 activity could be a target to restore altered T cell functions in aging. These observations could have far reaching consequences for improvement of immunosenescence and its clinical consequences such as infections, altered response to vaccination.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Tamas Fülöp
- Research Center on Aging, Faculty of Medicine and Health Sciences, Université de Sherbrooke, 1036 rue Belvedere sud, Sherbrooke, J1H 4C4, Quebec, Canada.
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