1
|
Cross K. Psychoacoustic Similarity Judgments in Expert Rappers and Laypersons. J Psycholinguist Res 2023; 52:1141-1170. [PMID: 36929042 DOI: 10.1007/s10936-023-09932-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 01/02/2023] [Indexed: 06/18/2023]
Abstract
This study sought to determine whether rap expertise is associated with enhanced knowledge of psychoacoustic similarity. Using a stimulus composed of pseudo-word assonantal half-rhyme triplets (e.g., freet/speet//yeek), expert improvisational rap lyricists were compared to laypersons (non-lyricists) in their judgments of half-rhyme acceptability. According to both a perception-based and a linguistic feature-based measure of psychoacoustic similarity, lyricists were distinct from non-lyricists in the rates at which they found half-rhymes acceptable, and in how group responses were correlated with the similarity measures. Data indicate that, compared to non-lyricists, lyricists' half-rhyme acceptance rates are more highly correlated with linguistic features that have more robust perceptual cues. Evidence suggests that lyricists and non-lyricists employ different strategies for determining the acceptability of half-rhymes, and that lyricists might be more sensitive or attuned to similar aspects of speech sounds.
Collapse
|
2
|
Cho KJ, Liang JR, Crespo P, Aran V. Editorial: Ras and Other GTPases in Cancer: From Basic to Applied Research. Front Mol Biosci 2021; 8:804818. [PMID: 34912854 PMCID: PMC8666501 DOI: 10.3389/fmolb.2021.804818] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 11/09/2021] [Indexed: 11/25/2022] Open
Affiliation(s)
- Kwang-Jin Cho
- Department of Biochemistry and Molecular Biology, Boonshoft School of Medicine, Wright State University, Dayton, OH, United States
| | - Jin Rui Liang
- Department of Biology, ETH Zürich, Zürich, Switzerland
| | - Piero Crespo
- Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Consejo Superior de Investigaciones Científicas (CSIC)-Universidad de Cantabria, Santander, Spain
| | - Veronica Aran
- Instituto Estadual do Cérebro Paulo Niemeyer, Rio de Janeiro, Brazil
| |
Collapse
|
3
|
Manzano S, Gutierrez-Uzquiza A, Bragado P, Cuesta AM, Guerrero C, Porras A. C3G Protein, a New Player in Glioblastoma. Int J Mol Sci 2021; 22:10018. [PMID: 34576182 DOI: 10.3390/ijms221810018] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 08/09/2021] [Accepted: 09/13/2021] [Indexed: 12/04/2022] Open
Abstract
C3G (RAPGEF1) is a guanine nucleotide exchange factor (GEF) for GTPases from the Ras superfamily, mainly Rap1, although it also acts through GEF-independent mechanisms. C3G regulates several cellular functions. It is expressed at relatively high levels in specific brain areas, playing important roles during embryonic development. Recent studies have uncovered different roles for C3G in cancer that are likely to depend on cell context, tumour type, and stage. However, its role in brain tumours remained unknown until very recently. We found that C3G expression is downregulated in GBM, which promotes the acquisition of a more mesenchymal phenotype, enhancing migration and invasion, but not proliferation. ERKs hyperactivation, likely induced by FGFR1, is responsible for this pro-invasive effect detected in C3G silenced cells. Other RTKs (Receptor Tyrosine Kinases) are also dysregulated and could also contribute to C3G effects. However, it remains undetermined whether Rap1 is a mediator of C3G actions in GBM. Various Rap1 isoforms can promote proliferation and invasion in GBM cells, while C3G inhibits migration/invasion. Therefore, other RapGEFs could play a major role regulating Rap1 activity in these tumours. Based on the information available, C3G could represent a new biomarker for GBM diagnosis, prognosis, and personalised treatment of patients in combination with other GBM molecular markers. The quantification of C3G levels in circulating tumour cells (CTCs) in the cerebrospinal liquid and/or circulating fluids might be a useful tool to improve GBM patient treatment and survival.
Collapse
|
4
|
Abstract
Ras and its related small GTPases are important signalling nodes that regulate a wide variety of cellular functions. The active form of these proteins exists in a transient GTP bound state that mediates downstream signalling events. The dysregulation of these GTPases has been associated with the progression of multiple diseases, most prominently cancer and developmental syndromes known as Rasopathies. Determining the activation state of Ras and its relatives has hence been of paramount importance for the investigation of the biochemical functions of small GTPases in the cellular signal transduction network. This chapter describes the most broadly employed approach for the rapid, label-free qualitative and semi-quantitative determination of the Ras GTPase activation state, which can readily be adapted to the analysis of other related GTPases. The method relies on the affinity-based isolation of the active GTP-bound fraction of Ras in cellular extracts, followed by its visualization via western blotting. Specifically, we describe the production of the recombinant affinity probes or baits that bind to the respective active GTPases and the pulldown method for isolating the active GTPase fraction from adherent or non-adherent cells. This method allows for the reproducible measurement of active Ras or Ras family GTPases in a wide variety of cellular contexts.
Collapse
Affiliation(s)
- Martin J Baker
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Ignacio Rubio
- Institute of Molecular Cell Biology, Center for Molecular Biomedicine, University Hospital Jena, Jena, Germany. .,Clinic for Anaesthesiology and Intensive Care, University Hospital Jena, Jena, Germany.
| |
Collapse
|
5
|
Jang YN, Jang H, Kim GH, Noh JE, Chang KA, Lee KJ. RAPGEF2 mediates oligomeric Aβ-induced synaptic loss and cognitive dysfunction in the 3xTg-AD mouse model of Alzheimer's disease. Neuropathol Appl Neurobiol 2021; 47:625-639. [PMID: 33345400 PMCID: PMC8359155 DOI: 10.1111/nan.12686] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 11/03/2020] [Accepted: 12/14/2020] [Indexed: 12/20/2022]
Abstract
AIMS Amyloid-β (Aβ) oligomers trigger synaptic degeneration that precedes plaque and tangle pathology. However, the signalling molecules that link Aβ oligomers to synaptic pathology remain unclear. Here, we addressed the potential role of RAPGEF2 as a novel signalling molecule in Aβ oligomer-induced synaptic and cognitive impairments in human-mutant amyloid precursor protein (APP) mouse models of Alzheimer's disease (AD). METHODS To investigate the role of RAPGEF2 in Aβ oligomer-induced synaptic and cognitive impairments, we utilised a combination of approaches including biochemistry, molecular cell biology, light and electron microscopy, behavioural tests with primary neuron cultures, multiple AD mouse models and post-mortem human AD brain tissue. RESULTS We found significantly elevated RAPGEF2 levels in the post-mortem human AD hippocampus. RAPGEF2 levels also increased in the transgenic AD mouse models, generating high levels of Aβ oligomers before exhibiting synaptic and cognitive impairment. RAPGEF2 upregulation activated the downstream effectors Rap2 and JNK. In cultured hippocampal neurons, oligomeric Aβ treatment increased the fluorescence intensity of RAPGEF2 and reduced the number of dendritic spines and the intensities of synaptic marker proteins, while silencing RAPGEF2 expression blocked Aβ oligomer-induced synapse loss. Additionally, the in vivo knockdown of RAPGEF2 expression in the AD hippocampus prevented cognitive deficits and the loss of excitatory synapses. CONCLUSIONS These findings demonstrate that the upregulation of RAPGEF2 levels mediates Aβ oligomer-induced synaptic and cognitive disturbances in the AD hippocampus. We propose that an early intervention regarding RAPGEF2 expression may have beneficial effects on early synaptic pathology and memory loss in AD.
Collapse
Affiliation(s)
- You-Na Jang
- Neural Circuits Research Group, Korea Brain Research Institute, Daegu, Republic of Korea
| | - HoChung Jang
- Neural Circuits Research Group, Korea Brain Research Institute, Daegu, Republic of Korea
| | - Gyu Hyun Kim
- Neural Circuits Research Group, Korea Brain Research Institute, Daegu, Republic of Korea
| | - Jeong-Eun Noh
- Neural Circuits Research Group, Korea Brain Research Institute, Daegu, Republic of Korea
| | - Keun-A Chang
- Department of Pharmacology, College of Medicine, Gachon University, Incheon, Republic of Korea
| | - Kea Joo Lee
- Neural Circuits Research Group, Korea Brain Research Institute, Daegu, Republic of Korea.,Department of Brain and Cognitive Sciences, DGIST, Daegu, Republic of Korea
| |
Collapse
|
6
|
Abstract
During the last decade, drug abuse rates, particularly prescription drugs, have increased. Simultaneously, music consumption has dramatically increased, and the leading genre is currently rap music. While the casual relationship is debated, musical preference is related to substance misuse and other risky behaviors. There is a lack of studies examining rap music and references to specific types and forms of drugs. Objective: The present study seeks to broaden the understanding of the messages related to substance misuse within rap music over time. Method: A lyrical content evaluation of the top 25 most popular rap songs between 2006 and 2018 (n = 325) identifying references to alcohol, illicit, and prescription drug misuse. Results: 72% (n = 233) of popular rap songs contain references to one or more substances, with 947 references, which resulted in 63 references to drugs or alcohol after just one hour of listening. Further, 50% of songs included illicit drug references, including marijuana (38%), manufacturing or selling drugs (19%), cocaine or crack (17%), and MDMA (6%). Prescription drug misuse occurred in 20% of songs, including; prescription cold medication (13%), other types of opioids (4%), and various other prescriptions (e.g. Xanax & Adderall) (10%). Yearly trends indicate that alcohol lyrics are declining, illicit drug lyrics remain stable, and prescription drug lyrics increase. Conclusions/Importance: The rise in music consumption with rap music leading in popularity and 72% of songs celebrating drug usage is a concerning trend, especially as prescription drug misuse is rising in popularity within rap music.
Collapse
Affiliation(s)
- Ben Stickle
- Criminal Justice Administration, Middle Tennessee State Univeristy, Murfreesboro, Tennessee, USA
| |
Collapse
|
7
|
Thomas K, Ayse C, Natalia K, Peter B, Bedriye SH, Praveen G, Hakan A, Markus S, Wolfgang S, Yeong-Hoon C, Miroslav B, Manfred R. The MEK/ERK Module Is Reprogrammed in Remodeling Adult Cardiomyocytes. Int J Mol Sci 2020; 21:ijms21176348. [PMID: 32882982 PMCID: PMC7503571 DOI: 10.3390/ijms21176348] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 08/26/2020] [Accepted: 08/30/2020] [Indexed: 12/18/2022] Open
Abstract
Fetal and hypertrophic remodeling are hallmarks of cardiac restructuring leading chronically to heart failure. Since the Ras/Raf/MEK/ERK cascade (MAPK) is involved in the development of heart failure, we hypothesized, first, that fetal remodeling is different from hypertrophy and, second, that remodeling of the MAPK occurs. To test our hypothesis, we analyzed models of cultured adult rat cardiomyocytes as well as investigated myocytes in the failing human myocardium by western blot and confocal microscopy. Fetal remodeling was induced through endothelial morphogens and monitored by the reexpression of Acta2, Actn1, and Actb. Serum-induced hypertrophy was determined by increased surface size and protein content of cardiomyocytes. Serum and morphogens caused reprogramming of Ras/Raf/MEK/ERK. In both models H-Ras, N-Ras, Rap2, B- and C-Raf, MEK1/2 as well as ERK1/2 increased while K-Ras was downregulated. Atrophy, MAPK-dependent ischemic resistance, loss of A-Raf, and reexpression of Rap1 and Erk3 highlighted fetal remodeling, while A-Raf accumulation marked hypertrophy. The knock-down of B-Raf by siRNA reduced MAPK activation and fetal reprogramming. In conclusion, we demonstrate that fetal and hypertrophic remodeling are independent processes and involve reprogramming of the MAPK.
Collapse
Affiliation(s)
- Kubin Thomas
- Department of Cardiac Surgery, Kerckhoff Heart Center, Benekestrasse 2-8, 61231 Bad Nauheim, Germany; (C.A.); (K.N.); (G.P.); (S.M.); (C.Y.-H.)
- Campus Kerckhoff, Justus-Liebig-University Giessen, 61231 Bad Nauheim, Germany
- Correspondence: (K.T.); (B.M.); (R.M.)
| | - Cetinkaya Ayse
- Department of Cardiac Surgery, Kerckhoff Heart Center, Benekestrasse 2-8, 61231 Bad Nauheim, Germany; (C.A.); (K.N.); (G.P.); (S.M.); (C.Y.-H.)
- Campus Kerckhoff, Justus-Liebig-University Giessen, 61231 Bad Nauheim, Germany
| | - Kubin Natalia
- Department of Cardiac Surgery, Kerckhoff Heart Center, Benekestrasse 2-8, 61231 Bad Nauheim, Germany; (C.A.); (K.N.); (G.P.); (S.M.); (C.Y.-H.)
- Campus Kerckhoff, Justus-Liebig-University Giessen, 61231 Bad Nauheim, Germany
| | - Bramlage Peter
- Institute for Pharmacology and Preventive Medicine, Bahnhofstraße 20, 49661 Cloppenburg, Germany;
| | - Sen-Hild Bedriye
- Pediatric Heart Center, Justus Liebig University, Feulgenstrasse 10-12, 35392 Giessen, Germany; (S.-H.B.); (A.H.)
| | - Gajawada Praveen
- Department of Cardiac Surgery, Kerckhoff Heart Center, Benekestrasse 2-8, 61231 Bad Nauheim, Germany; (C.A.); (K.N.); (G.P.); (S.M.); (C.Y.-H.)
- Campus Kerckhoff, Justus-Liebig-University Giessen, 61231 Bad Nauheim, Germany
| | - Akintürk Hakan
- Pediatric Heart Center, Justus Liebig University, Feulgenstrasse 10-12, 35392 Giessen, Germany; (S.-H.B.); (A.H.)
| | - Schönburg Markus
- Department of Cardiac Surgery, Kerckhoff Heart Center, Benekestrasse 2-8, 61231 Bad Nauheim, Germany; (C.A.); (K.N.); (G.P.); (S.M.); (C.Y.-H.)
- Campus Kerckhoff, Justus-Liebig-University Giessen, 61231 Bad Nauheim, Germany
| | - Schaper Wolfgang
- Max-Planck-Institute for Heart and Lung Research, 61231 Bad Nauheim, Germany;
| | - Choi Yeong-Hoon
- Department of Cardiac Surgery, Kerckhoff Heart Center, Benekestrasse 2-8, 61231 Bad Nauheim, Germany; (C.A.); (K.N.); (G.P.); (S.M.); (C.Y.-H.)
- Campus Kerckhoff, Justus-Liebig-University Giessen, 61231 Bad Nauheim, Germany
- German Center for Cardiovascular Research (DZHK), Partner Site RhineMain, 60590 Frankfurt/Main, Germany
| | - Barancik Miroslav
- Centre of Experimental Medicine, Institute for Heart Research, Slovak Academy of Sciences, 84104 Bratislava, Slovakia
- Correspondence: (K.T.); (B.M.); (R.M.)
| | - Richter Manfred
- Department of Cardiac Surgery, Kerckhoff Heart Center, Benekestrasse 2-8, 61231 Bad Nauheim, Germany; (C.A.); (K.N.); (G.P.); (S.M.); (C.Y.-H.)
- Campus Kerckhoff, Justus-Liebig-University Giessen, 61231 Bad Nauheim, Germany
- Correspondence: (K.T.); (B.M.); (R.M.)
| |
Collapse
|
8
|
Arrazola Sastre A, Luque Montoro M, Gálvez-Martín P, Lacerda HM, Lucia A, Llavero F, Zugaza JL. Small GTPases of the Ras and Rho Families Switch on/off Signaling Pathways in Neurodegenerative Diseases. Int J Mol Sci 2020; 21:E6312. [PMID: 32878220 PMCID: PMC7504559 DOI: 10.3390/ijms21176312] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2020] [Revised: 08/28/2020] [Accepted: 08/29/2020] [Indexed: 12/16/2022] Open
Abstract
Small guanosine triphosphatases (GTPases) of the Ras superfamily are key regulators of many key cellular events such as proliferation, differentiation, cell cycle regulation, migration, or apoptosis. To control these biological responses, GTPases activity is regulated by guanine nucleotide exchange factors (GEFs), GTPase activating proteins (GAPs), and in some small GTPases also guanine nucleotide dissociation inhibitors (GDIs). Moreover, small GTPases transduce signals by their downstream effector molecules. Many studies demonstrate that small GTPases of the Ras family are involved in neurodegeneration processes. Here, in this review, we focus on the signaling pathways controlled by these small protein superfamilies that culminate in neurodegenerative pathologies, such as Alzheimer's disease (AD) and Parkinson's disease (PD). Specifically, we concentrate on the two most studied families of the Ras superfamily: the Ras and Rho families. We summarize the latest findings of small GTPases of the Ras and Rho families in neurodegeneration in order to highlight these small proteins as potential therapeutic targets capable of slowing down different neurodegenerative diseases.
Collapse
Affiliation(s)
- Alazne Arrazola Sastre
- Achucarro Basque Center for Neuroscience, Science Park of the Universidad del País Vasco/Euskal Herriko Unibertsitatea (UPV/EHU), 48940 Leioa, Spain; (A.A.S.); (M.L.M.)
- Department of Genetics, Physical Anthropology, and Animal Physiology, Faculty of Science and Technology, UPV/EHU, 48940 Leioa, Spain
| | - Miriam Luque Montoro
- Achucarro Basque Center for Neuroscience, Science Park of the Universidad del País Vasco/Euskal Herriko Unibertsitatea (UPV/EHU), 48940 Leioa, Spain; (A.A.S.); (M.L.M.)
| | - Patricia Gálvez-Martín
- Department of Pharmacy and Pharmaceutical Technology, Faculty of Pharmacy, University of Granada, 180041 Granada, Spain;
- R&D Human Health, Bioibérica S.A.U., 08950 Barcelona, Spain
| | | | - Alejandro Lucia
- Faculty of Sport Science, European University of Madrid, 28670 Madrid, Spain;
- Research Institute of the Hospital 12 de Octubre (i+12), 28041 Madrid, Spain
| | - Francisco Llavero
- Achucarro Basque Center for Neuroscience, Science Park of the Universidad del País Vasco/Euskal Herriko Unibertsitatea (UPV/EHU), 48940 Leioa, Spain; (A.A.S.); (M.L.M.)
- Faculty of Sport Science, European University of Madrid, 28670 Madrid, Spain;
| | - José Luis Zugaza
- Achucarro Basque Center for Neuroscience, Science Park of the Universidad del País Vasco/Euskal Herriko Unibertsitatea (UPV/EHU), 48940 Leioa, Spain; (A.A.S.); (M.L.M.)
- Department of Genetics, Physical Anthropology, and Animal Physiology, Faculty of Science and Technology, UPV/EHU, 48940 Leioa, Spain
- IKERBASQUE, Basque Foundation for Science, 48013 Bilbao, Spain
| |
Collapse
|
9
|
Noyer L, Lemonnier L, Mariot P, Gkika D. Partners in Crime: Towards New Ways of Targeting Calcium Channels. Int J Mol Sci 2019; 20:ijms20246344. [PMID: 31888223 PMCID: PMC6940757 DOI: 10.3390/ijms20246344] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 12/05/2019] [Accepted: 12/13/2019] [Indexed: 12/16/2022] Open
Abstract
The characterization of calcium channel interactome in the last decades opened a new way of perceiving ion channel function and regulation. Partner proteins of ion channels can now be considered as major components of the calcium homeostatic mechanisms, while the reinforcement or disruption of their interaction with the channel units now represents an attractive target in research and therapeutics. In this review we will focus on the targeting of calcium channel partner proteins in order to act on the channel activity, and on its consequences for cell and organism physiology. Given the recent advances in the partner proteins’ identification, characterization, as well as in the resolution of their interaction domain structures, we will develop the latest findings on the interacting proteins of the following channels: voltage-dependent calcium channels, transient receptor potential and ORAI channels, and inositol 1,4,5-trisphosphate receptor.
Collapse
Affiliation(s)
- Lucile Noyer
- Univ. Lille, Inserm, U1003-PHYCEL-Physiologie Cellulaire, F-59000 Lille, France; (L.N.); (L.L.); (P.M.)
- Laboratory of Excellence, Ion Channels Science and Therapeutics, Université de Lille, 59655 Villeneuve d’Ascq, France
| | - Loic Lemonnier
- Univ. Lille, Inserm, U1003-PHYCEL-Physiologie Cellulaire, F-59000 Lille, France; (L.N.); (L.L.); (P.M.)
- Laboratory of Excellence, Ion Channels Science and Therapeutics, Université de Lille, 59655 Villeneuve d’Ascq, France
| | - Pascal Mariot
- Univ. Lille, Inserm, U1003-PHYCEL-Physiologie Cellulaire, F-59000 Lille, France; (L.N.); (L.L.); (P.M.)
- Laboratory of Excellence, Ion Channels Science and Therapeutics, Université de Lille, 59655 Villeneuve d’Ascq, France
| | - Dimitra Gkika
- Univ. Lille, Inserm, U1003-PHYCEL-Physiologie Cellulaire, F-59000 Lille, France; (L.N.); (L.L.); (P.M.)
- Laboratory of Excellence, Ion Channels Science and Therapeutics, Université de Lille, 59655 Villeneuve d’Ascq, France
- Correspondence: ; Tél.: +33-(0)3-2043-6838
| |
Collapse
|
10
|
Xu Y, Schwede F, Wienk H, Tengholm A, Rehmann H. A Membrane Permeable Prodrug of S223 for Selective Epac2 Activation in Living Cells. Cells 2019; 8:cells8121589. [PMID: 31817822 PMCID: PMC6952820 DOI: 10.3390/cells8121589] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 12/03/2019] [Accepted: 12/04/2019] [Indexed: 12/22/2022] Open
Abstract
Signalling by cyclic adenosine monophosphate (cAMP) occurs via various effector proteins, notably protein kinase A and the guanine nucleotide exchange factors Epac1 and Epac2. These proteins are activated by cAMP binding to conserved cyclic nucleotide binding domains. The specific roles of the effector proteins in various processes in different types of cells are still not well defined, but investigations have been facilitated by the development of cyclic nucleotide analogues with distinct selectivity profiles towards a single effector protein. A remaining challenge in the development of such analogues is the poor membrane permeability of nucleotides, which limits their applicability in intact living cells. Here, we report the synthesis and characterisation of S223-AM, a cAMP analogue designed as an acetoxymethyl ester prodrug to overcome limitations of permeability. Using total internal reflection imaging with various fluorescent reporters, we show that S223-AM selectively activates Epac2, but not Epac1 or protein kinase A, in intact insulin-secreting β-cells, and that this effect was associated with pronounced activation of the small G-protein Rap. A comparison of the effects of different cAMP analogues in pancreatic islet cells deficient in Epac1 and Epac2 demonstrates that cAMP-dependent Rap activity at the β-cell plasma membrane is exclusively dependent on Epac2. With its excellent selectivity and permeability properties, S223-AM should get broad utility in investigations of cAMP effector involvement in many different types of cells.
Collapse
Affiliation(s)
- Yunjian Xu
- Department of Medical Cell Biology, Uppsala University, Biomedical Centre, Box 571, SE-75123 Uppsala, Sweden; (Y.X.); (A.T.)
| | - Frank Schwede
- BIOLOG Life Science Institute, Flughafendamm 9a, 28199 Bremen, Germany;
| | - Hans Wienk
- NMR Spectroscopy, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands;
| | - Anders Tengholm
- Department of Medical Cell Biology, Uppsala University, Biomedical Centre, Box 571, SE-75123 Uppsala, Sweden; (Y.X.); (A.T.)
| | - Holger Rehmann
- Department of Molecular Cancer Research, Center for Molecular Medicine, Oncode Institute, University Medical Center Utrecht, 3584 CX Utrecht, The Netherlands
- Correspondence:
| |
Collapse
|
11
|
Sequera C, Manzano S, Guerrero C, Porras A. How Rap and its GEFs control liver physiology and cancer development. C3G alterations in human hepatocarcinoma. Hepat Oncol 2018; 5:HEP05. [PMID: 30302196 PMCID: PMC6168044 DOI: 10.2217/hep-2017-0026] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Accepted: 03/20/2018] [Indexed: 02/08/2023] Open
Abstract
Rap proteins regulate liver physiopathology. For example, Rap2B promotes hepatocarcinoma (HCC) growth, while Rap1 might play a dual role. The RapGEF, Epac1, activates Rap upon cAMP binding, regulating metabolism, survival, and liver regeneration. A liver specific Epac2 isoform lacking cAMP-binding domain also activates Rap1, promoting fibrosis in alcoholic liver disease. C3G (RapGEF1) is also present in the liver, but mainly as shorter isoforms. Its function in the liver remains unknown. Information from different public genetic databases revealed that C3G mRNA levels increase in HCC, although they decrease in metastatic stages. In addition, several mutations in RapGEF1 gene are present, associated with a reduced patient survival. Based on this, C3G might represent a new HCC diagnostic and prognostic marker, and a therapeutic target.
Collapse
Affiliation(s)
- Celia Sequera
- Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad Complutense de Madrid, Madrid, Spain.,Instituto de Investigación Sanitaria del Hospital Clínico San Carlos (IdISSC), Madrid, Spain.,Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad Complutense de Madrid, Madrid, Spain.,Instituto de Investigación Sanitaria del Hospital Clínico San Carlos (IdISSC), Madrid, Spain
| | - Sara Manzano
- Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad Complutense de Madrid, Madrid, Spain.,Instituto de Investigación Sanitaria del Hospital Clínico San Carlos (IdISSC), Madrid, Spain.,Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad Complutense de Madrid, Madrid, Spain.,Instituto de Investigación Sanitaria del Hospital Clínico San Carlos (IdISSC), Madrid, Spain
| | - Carmen Guerrero
- Instituto de Biología Molecular y Celular del Cáncer, USAL-CSIC, Salamanca, Spain.,Instituto de Investigación Biomédica de Salamanca (IBSAL), Salamanca, Spain.,Departamento de Medicina, Universidad de Salamanca, Salamanca, Spain.,Instituto de Biología Molecular y Celular del Cáncer, USAL-CSIC, Salamanca, Spain.,Instituto de Investigación Biomédica de Salamanca (IBSAL), Salamanca, Spain.,Departamento de Medicina, Universidad de Salamanca, Salamanca, Spain
| | - Almudena Porras
- Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad Complutense de Madrid, Madrid, Spain.,Instituto de Investigación Sanitaria del Hospital Clínico San Carlos (IdISSC), Madrid, Spain.,Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad Complutense de Madrid, Madrid, Spain.,Instituto de Investigación Sanitaria del Hospital Clínico San Carlos (IdISSC), Madrid, Spain
| |
Collapse
|
12
|
Park B, Kim H, Jeon TJ. Loss of RapC causes defects in cytokinesis, cell migration, and multicellular development of Dictyostelium. Biochem Biophys Res Commun 2018; 499:783-9. [PMID: 29614268 DOI: 10.1016/j.bbrc.2018.03.223] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2018] [Accepted: 03/30/2018] [Indexed: 11/22/2022]
Abstract
The small GTPase Ras proteins are involved in diverse cellular processes. We investigated the functions of RapC, one of 15 Ras subfamily GTPases in Dictyostelium. Loss of RapC resulted in a spread shape of cells; severe defects in cytokinesis leading to multinucleation; decrease of migration speed in chemoattractant-mediated cell migration, likely through increased cell adhesion; and aberrations in multicellular development producing abnormal multiple tips from one mound and multi-branched developmental structures. Defects in cells lacking RapC were rescued by expressing GFP-RapC in rapC null cells. Our results demonstrate that RapC, despite its high sequence homology with Rap1, plays a negative role in cell spreading and cell adhesion, in contrast to Rap1, which is a key regulator of cell adhesion and cytoskeleton rearrangement. In addition, RapC appears to have a unique function in multicellular development and is involved in tip formation from mounds. This study contributes to the understanding of Ras-mediated cellular processes.
Collapse
|
13
|
Griffin JN, del Viso F, Duncan AR, Robson A, Hwang W, Kulkarni S, Liu KJ, Khokha MK. RAPGEF5 Regulates Nuclear Translocation of β-Catenin. Dev Cell 2018; 44:248-260.e4. [PMID: 29290587 PMCID: PMC5818985 DOI: 10.1016/j.devcel.2017.12.001] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Revised: 09/04/2017] [Accepted: 11/30/2017] [Indexed: 12/16/2022]
Abstract
Canonical Wnt signaling coordinates many critical aspects of embryonic development, while dysregulated Wnt signaling contributes to common diseases, including congenital malformations and cancer. The nuclear localization of β-catenin is the defining step in pathway activation. However, despite intensive investigation, the mechanisms regulating β-catenin nuclear transport remain undefined. In a patient with congenital heart disease and heterotaxy, a disorder of left-right patterning, we previously identified the guanine nucleotide exchange factor, RAPGEF5. Here, we demonstrate that RAPGEF5 regulates left-right patterning via Wnt signaling. In particular, RAPGEF5 regulates the nuclear translocation of β-catenin independently of both β-catenin cytoplasmic stabilization and the importin β1/Ran-mediated transport system. We propose a model whereby RAPGEF5 activates the nuclear GTPases, Rap1a/b, to facilitate the nuclear transport of β-catenin, defining a parallel nuclear transport pathway to Ran. Our results suggest new targets for modulating Wnt signaling in disease states.
Collapse
Affiliation(s)
- John N. Griffin
- Pediatric Genomics Discovery Program, Departments of Pediatrics and Genetics, Yale University School of Medicine, 333 Cedar Street, New Haven, Connecticut 06510, USA,Centre for Craniofacial and Regenerative Biology, King’s College London, London SE1 9RT, United Kingdom
| | - Florencia del Viso
- Pediatric Genomics Discovery Program, Departments of Pediatrics and Genetics, Yale University School of Medicine, 333 Cedar Street, New Haven, Connecticut 06510, USA
| | - Anna R. Duncan
- Pediatric Genomics Discovery Program, Departments of Pediatrics and Genetics, Yale University School of Medicine, 333 Cedar Street, New Haven, Connecticut 06510, USA
| | - Andrew Robson
- Pediatric Genomics Discovery Program, Departments of Pediatrics and Genetics, Yale University School of Medicine, 333 Cedar Street, New Haven, Connecticut 06510, USA
| | - Woong Hwang
- Pediatric Genomics Discovery Program, Departments of Pediatrics and Genetics, Yale University School of Medicine, 333 Cedar Street, New Haven, Connecticut 06510, USA
| | - Saurabh Kulkarni
- Pediatric Genomics Discovery Program, Departments of Pediatrics and Genetics, Yale University School of Medicine, 333 Cedar Street, New Haven, Connecticut 06510, USA
| | - Karen J. Liu
- Centre for Craniofacial and Regenerative Biology, King’s College London, London SE1 9RT, United Kingdom
| | - Mustafa K. Khokha
- Pediatric Genomics Discovery Program, Departments of Pediatrics and Genetics, Yale University School of Medicine, 333 Cedar Street, New Haven, Connecticut 06510, USA,Correspondence to: Lead contact Mustafa Khokha,
| |
Collapse
|
14
|
Abstract
Rasal is a modular multi-domain protein of the GTPase-activating protein 1 (GAP1) family; its four known members, GAP1m, Rasal, GAP1IP4BP and Capri, have a Ras GTPase-activating domain (RasGAP). This domain supports the intrinsically slow GTPase activity of Ras by actively participating in the catalytic reaction. In the case of Rasal, GAP1IP4BP and Capri, their remaining domains are responsible for converting the RasGAP domains into dual Ras- and Rap-GAPs, via an incompletely understood mechanism. Although Rap proteins are small GTPase homologues of Ras, their catalytic residues are distinct, which reinforces the importance of determining the structure of full-length GAP1 family proteins. To date, these proteins have not been crystallized, and their size is not adequate for nuclear magnetic resonance (NMR) or for high-resolution cryo-electron microscopy (cryoEM). Here we present the low resolution structure of full-length Rasal, obtained by negative staining electron microscopy, which allows us to propose a model of its domain topology. These results help to understand the role of the different domains in controlling the dual GAP activity of GAP1 family proteins.
Collapse
Affiliation(s)
- Jorge Cuellar
- Department of Macromolecular Structures, Centro Nacional de Biotecnología (CNB-CSIC), Madrid, Spain
| | - José María Valpuesta
- Department of Macromolecular Structures, Centro Nacional de Biotecnología (CNB-CSIC), Madrid, Spain.,Unidad Asociada de Nanobiotecnología (CNB-CSIC e IMDEA Nanociencia), Madrid, Spain
| | - Alfred Wittinghofer
- Department of Structural Biology, Max-Planck-Institute for Molecular Physiology, Dortmund, Germany
| | - Begoña Sot
- Department of Macromolecular Structures, Centro Nacional de Biotecnología (CNB-CSIC), Madrid, Spain.,Unidad Asociada de Nanobiotecnología (CNB-CSIC e IMDEA Nanociencia), Madrid, Spain.,IMDEA-Nanociencia, Faraday 9, Campus Universitario de Cantoblanco, 28048 Madrid, Spain
| |
Collapse
|
15
|
Abstract
Epac1 and Epac2 are cyclic nucleotide-binding (CNB) domain containing proteins, which were originally identified as cAMP-regulated guanine nucleotide exchange factors (GEFs) for the small G-protein Rap. Therefore, Epac proteins founded next to protein kinase A (PKA) and cyclic nucleotide-regulated ion channels the third group of cAMP-responsive proteins in higher organisms. Epac proteins are involved in the regulation of several physiological processes. In particular Epac1 mediates the regulation of molecular processes underlying cell adhesion and mobility. In the pancreas activation of Epac2 potentiates the release of glucose-induced insulin secretion and received attention as a putative target for antidiabetic treatment. While the regulation of Epac by cAMP has been analysed in structural and biochemical detail, less is known on the interaction of Epac with non-canonical cyclic nucleotides. This chapter will discuss to what extent other cyclic purines than cAMP or cyclic pyrimidine could act as Epac agonists or antagonists. The focus will be on the biophysical analysis of the interaction between Epac and these cyclic nucleotides.
Collapse
Affiliation(s)
- Holger Rehmann
- Molecular Cancer Research and Cancer Genomics Netherlands, Center for Molecular Medicine, UMC Utrecht, Utrecht, The Netherlands.
| |
Collapse
|
16
|
Premkumar A, Brown K, Mengesha B, Jackson AV. Abortion and contemporary hip-hop: a thematic analysis of lyrics from 1990-2015. Contraception 2017; 96:30-5. [PMID: 28578149 DOI: 10.1016/j.contraception.2017.05.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Revised: 05/05/2017] [Accepted: 05/14/2017] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To evaluate the representation of abortion in contemporary hip-hop music, gaining insight into the myriad of attitudes of abortion in the black community. STUDY DESIGN We used Genius, an online storehouse for lyrical content, to identify songs by querying the database for search terms related to family planning, including slang terms. We then cross-referenced identified songs using an online list of songs about abortion. We analyzed eligible songs using grounded theory in order to identify key themes. RESULTS Of 6577 songs available, a total of 101 songs performed by 122 individual artists met inclusion criteria. The majority of artists were Black men; five artists were Black women. Key themes were: use of abortion as braggadocio; equating abortion with sin, genocide, or murder; male pressure for women to seek abortion; and the specific association of Planned Parenthood services with abortion. CONCLUSIONS The moral and ethical themes surrounding abortion in hip-hop lyrics reveal a unique perspective within a marginalized community. The overall negative context of abortion in hip-hop lyrics needs to be reconciled with the gendered, economic, historical, political, racial and ethnic background of hip-hop and rap music in America. IMPLICATIONS This study is the first to evaluate lyrical content from contemporary popular music in relation to abortion and family planning. Examining the intersection of reproductive rights and popular culture can provide a unique insight into the limited knowledge of the perspectives of abortion in the black community.
Collapse
|
17
|
Gingras AR, Puzon-McLaughlin W, Bobkov AA, Ginsberg MH. Structural Basis of Dimeric Rasip1 RA Domain Recognition of the Ras Subfamily of GTP-Binding Proteins. Structure 2016; 24:2152-62. [PMID: 27839947 DOI: 10.1016/j.str.2016.10.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Revised: 10/04/2016] [Accepted: 10/12/2016] [Indexed: 01/20/2023]
Abstract
Ras-interacting protein 1 (Rasip1) is an endothelial-specific Rap1 and Ras effector, important for vascular development and angiogenesis. Here, we report the crystal structure of the Rasip1 RA domain (RRA) alone, revealing the basis of dimerization, and in complex with Rap1 at 2.8 Å resolution. In contrast to most RA domains, RRA formed a dimer that can bind two Rap1 (KD = 0.9 μM) or Ras (KD = 2.2 μM) molecules. We solved the Rap1-RRA complex and found that Rasip1 binds Rap1 in the Switch I region, and Rap1 binding induces few conformation changes to Rasip1 stabilizing a β strand and an unstructured loop. Our data explain how Rasip1 can act as a Rap1 and Ras effector and show that Rasip1 defines a subgroup of dimeric RA domains that could mediate cooperative binding to membrane-associated Ras superfamily members.
Collapse
|
18
|
Pascoe HG, Wang Y, Zhang X. In Vitro Assay for the Rap GTPase-Activating Protein Activity of the Purified Cytoplasmic Domain of Plexin. Methods Mol Biol 2017; 1493:107-18. [PMID: 27787845 DOI: 10.1007/978-1-4939-6448-2_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Plexins are cell surface receptors that bind semaphorins and regulate essential processes such as axon guidance and angiogenesis. The cytoplasmic regions of plexins contain a functionally essential GTPase-activating protein (GAP) domain, which initiates downstream signaling by specifically inactivating the Rap GTPase. Here we describe the methods for expression and purification of the plexin cytoplasmic region in E. coli, and characterization of its GAP activity using a photometric assay. We also provide a protocol for measuring GAP activity of single-chain constructs with Rap covalently linked to the plexin cytoplasmic region.
Collapse
|
19
|
Abstract
The directional movement toward extracellular chemical gradients, a process called chemotaxis, is an important property of cells. Central to eukaryotic chemotaxis is the molecular mechanism by which chemoattractant-mediated activation of G-protein coupled receptors (GPCRs) induces symmetry breaking in the activated downstream signaling pathways. Studies with mainly Dictyostelium and mammalian neutrophils as experimental systems have shown that chemotaxis is mediated by a complex network of signaling pathways. Recently, several labs have used extensive and efficient proteomic approaches to further unravel this dynamic signaling network. Together these studies showed the critical role of the interplay between heterotrimeric G-protein subunits and monomeric G proteins in regulating cytoskeletal rearrangements during chemotaxis. Here we highlight how these proteomic studies have provided greater insight into the mechanisms by which the heterotrimeric G protein cycle is regulated, how heterotrimeric G proteins-induced symmetry breaking is mediated through small G protein signaling, and how symmetry breaking in G protein signaling subsequently induces cytoskeleton rearrangements and cell migration.
Collapse
Affiliation(s)
- Youtao Liu
- a Department of Cell Biochemistry , University of Groningen , Groningen , The Netherlands
| | - Jesus Lacal
- b Section of Cell and Developmental Biology, Division of Biological Sciences, University of California , San Diego, La Jolla , CA , USA
| | - Richard A Firtel
- b Section of Cell and Developmental Biology, Division of Biological Sciences, University of California , San Diego, La Jolla , CA , USA
| | - Arjan Kortholt
- a Department of Cell Biochemistry , University of Groningen , Groningen , The Netherlands
| |
Collapse
|
20
|
Sugawara K, Shibasaki T, Takahashi H, Seino S. Structure and functional roles of Epac2 ( Rapgef4). Gene 2015; 575:577-83. [PMID: 26390815 DOI: 10.1016/j.gene.2015.09.029] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Revised: 08/13/2015] [Accepted: 09/15/2015] [Indexed: 10/24/2022]
Abstract
Epac (exchange protein activated by cyclic-AMP) 2 is a direct target of 3'-5'-cyclic adenosine monophosphate (cAMP) and is involved in cAMP-mediated signal transduction through activation of the Ras-like small GTPase Rap. Crystallographic analyses revealed that activation of Epac2 by cAMP is accompanied by dynamic structural changes. Epac2 is expressed mainly in brain, neuroendocrine and endocrine tissues, and is involved in diverse cellular functions in the tissues. In this review, we summarize the structure and function of Epac2. We also discuss the physiological and pathophysiological roles of Epac2, and the possibility of Epac2 as a therapeutic target.
Collapse
Affiliation(s)
- Kenji Sugawara
- Division of Diabetes and Endocrinology, Kobe University Graduate School of Medicine, Kobe, Japan; Division of Molecular and Metabolic Medicine, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Tadao Shibasaki
- Division of Molecular and Metabolic Medicine, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Harumi Takahashi
- Division of Molecular and Metabolic Medicine, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Susumu Seino
- Division of Molecular and Metabolic Medicine, Kobe University Graduate School of Medicine, Kobe, Japan.
| |
Collapse
|
21
|
Abstract
Signaling through plexin, the major cell surface receptor for semaphorin, plays critical roles in regulating processes such as neuronal axon guidance, angiogenesis and immune response. Plexin is normally kept inactive in the absence of semaphorin. Upon binding of semaphorin to the extracellular region, plexin is activated and transduces signal to the inside of the cell through its cytoplasmic region. The GTPase Activating Protein (GAP) domain in the plexin cytoplasmic region mediates the major intracellular signaling pathway. The substrate specificity and regulation mechanisms of the GAP domain have only been revealed recently. Many intracellular proteins serve as either upstream regulators or downstream transducers by directly interacting with plexin. The mechanisms of action for some of these proteins also start to emerge from recent studies. We review here these advances in the mechanistic understanding of plexin intracellular signaling from a structural perspective.
Collapse
Affiliation(s)
- Heath G Pascoe
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Yuxiao Wang
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Xuewu Zhang
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX, USA; Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, USA.
| |
Collapse
|
22
|
Schurmans S, Polizzi S, Scoumanne A, Sayyed S, Molina-Ortiz P. The Ras/ Rap GTPase activating protein RASA3: from gene structure to in vivo functions. Adv Biol Regul 2014; 57:153-61. [PMID: 25294679 DOI: 10.1016/j.jbior.2014.09.006] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2014] [Revised: 09/01/2014] [Accepted: 09/02/2014] [Indexed: 01/28/2023]
Abstract
RASA3 (or GTPase Activating Protein III, R-Ras GTPase-activating protein, GAP1(IP4BP)) is a GTPase activating protein of the GAP1 subfamily which targets Ras and Rap1. RASA3 was originally purified from pig platelet membranes through its intrinsic ability to bind inositol 1,3,4,5-tetrakisphosphate (I(1,3,4,5)P4) with high affinity, hence its first name GAP1(IP4BP) (for GAP1 subfamily member which binds I(1,3,4,5)P4). RASA3 was thus the first I(1,3,4,5)P4 receptor identified and cloned. The in vitro and in vivo functions of RASA3 remained somewhat elusive for a long time. However, recently, using genetically-modified mice and cells derived from these mice, the function of RASA3 during megakaryopoiesis, megakaryocyte adhesion and migration as well as integrin signaling has been reported. The goal of this review is thus to summarize and comment recent and less recent data in the literature on RASA3, in particular on the in vivo function of this specific GAP1 subfamily member.
Collapse
Affiliation(s)
- Stéphane Schurmans
- Laboratoire de Génétique Fonctionnelle, GIGA-Signal Transduction, GIGA B34, Université de Liège, Avenue de l'Hôpital 1, B-4000 Liège, Belgium; Secteur de Biochimie Métabolique, Département des Sciences Fonctionnelles, Faculté de Médecine Vétérinaire, Université de Liège, Boulevard de Colonster 20, 4000 Liège, Belgium; Welbio, Belgium.
| | - Séléna Polizzi
- Institut de Recherches Interdisciplinaires en Biologie Humaine et Moléculaire (IRIBHM), Institut de Biologie et de Médecine Moléculaires (IBMM), Faculté de Médecine, Université Libre de Bruxelles, Rue des Professeurs Jeener et Brachet 12, 6041 Gosselies, Belgium.
| | - Ariane Scoumanne
- Laboratoire de Génétique Fonctionnelle, GIGA-Signal Transduction, GIGA B34, Université de Liège, Avenue de l'Hôpital 1, B-4000 Liège, Belgium; Welbio, Belgium
| | - Sufyan Sayyed
- Laboratoire de Génétique Fonctionnelle, GIGA-Signal Transduction, GIGA B34, Université de Liège, Avenue de l'Hôpital 1, B-4000 Liège, Belgium
| | - Patricia Molina-Ortiz
- Laboratoire de Génétique Fonctionnelle, GIGA-Signal Transduction, GIGA B34, Université de Liège, Avenue de l'Hôpital 1, B-4000 Liège, Belgium; Welbio, Belgium
| |
Collapse
|
23
|
Abstract
Chronic lymphocytic leukemia (CLL) cells proliferate predominantly in niches in the lymph nodes, where signaling from the B cell receptor (BCR) and the surrounding microenvironment are critical for disease progression. In addition, leukemic cells traffic constantly from the bloodstream into the lymph nodes, migrate within lymphatic tissues and egress back to the bloodstream. These processes are driven by chemokines and their receptors, and depend on changes in cell migration and integrin-mediated adhesion. Here we describe how Rho and Rap guanosine triphosphatases (GTPases) contribute to both BCR signaling and chemokine receptor signaling, particularly by regulating cytoskeletal dynamics and integrin activity. We propose that new inhibitors of BCR-activated kinases are likely to affect CLL cell trafficking via Rho and Rap GTPases, and that upstream regulators or downstream effectors could be good targets for therapeutic intervention in CLL.
Collapse
Affiliation(s)
- Silvia Mele
- Randall Division of Cell and Molecular Biophysics, King's College London , London , UK
| | | | | |
Collapse
|
24
|
Futosi K, Fodor S, Mócsai A. Reprint of Neutrophil cell surface receptors and their intracellular signal transduction pathways. Int Immunopharmacol 2013; 17:1185-97. [PMID: 24263067 DOI: 10.1016/j.intimp.2013.11.010] [Citation(s) in RCA: 125] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2012] [Revised: 12/07/2012] [Accepted: 06/09/2013] [Indexed: 12/13/2022]
Abstract
Neutrophils play a critical role in the host defense against bacterial and fungal infections, but their inappropriate activation also contributes to tissue damage during autoimmune and inflammatory diseases. Neutrophils express a large number of cell surface receptors for the recognition of pathogen invasion and the inflammatory environment. Those include G-protein-coupled chemokine and chemoattractant receptors, Fc-receptors, adhesion receptors such as selectins/selectin ligands and integrins, various cytokine receptors, as well as innate immune receptors such as Toll-like receptors and C-type lectins. The various cell surface receptors trigger very diverse signal transduction pathways including activation of heterotrimeric and monomeric G-proteins, receptor-induced and store-operated Ca(2+) signals, protein and lipid kinases, adapter proteins and cytoskeletal rearrangement. Here we provide an overview of the receptors involved in neutrophil activation and the intracellular signal transduction processes they trigger. This knowledge is crucial for understanding how neutrophils participate in antimicrobial host defense and inflammatory tissue damage and may also point to possible future targets of the pharmacological therapy of neutrophil-mediated autoimmune or inflammatory diseases.
Collapse
Affiliation(s)
- Krisztina Futosi
- Department of Physiology, Semmelweis University School of Medicine, 1094 Budapest, Hungary
| | | | | |
Collapse
|
25
|
Citalán-Madrid AF, García-Ponce A, Vargas-Robles H, Betanzos A, Schnoor M. Small GTPases of the Ras superfamily regulate intestinal epithelial homeostasis and barrier function via common and unique mechanisms. Tissue Barriers 2013; 1:e26938. [PMID: 24868497 PMCID: PMC3942330 DOI: 10.4161/tisb.26938] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Revised: 10/21/2013] [Accepted: 10/24/2013] [Indexed: 12/11/2022] Open
Abstract
The intestinal epithelium forms a stable barrier protecting underlying tissues from pathogens in the gut lumen. This is achieved by specialized integral membrane structures such as tight and adherens junctions that connect neighboring cells and provide stabilizing links to the cytoskeleton. Junctions are constantly remodeled to respond to extracellular stimuli. Assembly and disassembly of junctions is regulated by interplay of actin remodeling, endocytotic recycling of junctional proteins, and various signaling pathways. Accumulating evidence implicate small G proteins of the Ras superfamily as important signaling molecules for the regulation of epithelial junctions. They function as molecular switches circling between an inactive GDP-bound and an active GTP-bound state. Once activated, they bind different effector molecules to control cellular processes required for correct junction assembly, maintenance and remodelling. Here, we review recent advances in understanding how GTPases of the Rho, Ras, Rab and Arf families contribute to intestinal epithelial homeostasis.
Collapse
Affiliation(s)
- Alí Francisco Citalán-Madrid
- Department of Molecular Biomedicine; Center for Research and Advanced Studies of the National Polytechnic Institute (Cinvestav del IPN); Mexico City, Mexico
| | - Alexander García-Ponce
- Department of Molecular Biomedicine; Center for Research and Advanced Studies of the National Polytechnic Institute (Cinvestav del IPN); Mexico City, Mexico
| | - Hilda Vargas-Robles
- Department of Molecular Biomedicine; Center for Research and Advanced Studies of the National Polytechnic Institute (Cinvestav del IPN); Mexico City, Mexico
| | - Abigail Betanzos
- Department of Infectomics and Molecular Pathogenesis; Center for Research and Advanced Studies of the National Polytechnic Institute (Cinvestav del IPN); Mexico City, Mexico
| | - Michael Schnoor
- Department of Molecular Biomedicine; Center for Research and Advanced Studies of the National Polytechnic Institute (Cinvestav del IPN); Mexico City, Mexico
| |
Collapse
|
26
|
Wang Y, Pascoe HG, Brautigam CA, He H, Zhang X. Structural basis for activation and non-canonical catalysis of the Rap GTPase activating protein domain of plexin. eLife 2013; 2:e01279. [PMID: 24137545 PMCID: PMC3787391 DOI: 10.7554/elife.01279] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2013] [Accepted: 08/22/2013] [Indexed: 12/14/2022] Open
Abstract
Plexins are cell surface receptors that bind semaphorins and transduce signals for regulating neuronal axon guidance and other processes. Plexin signaling depends on their cytoplasmic GTPase activating protein (GAP) domain, which specifically inactivates the Ras homolog Rap through an ill-defined non-canonical catalytic mechanism. The plexin GAP is activated by semaphorin-induced dimerization, the structural basis for which remained unknown. Here we present the crystal structures of the active dimer of zebrafish PlexinC1 cytoplasmic region in the apo state and in complex with Rap. The structures show that the dimerization induces a large-scale conformational change in plexin, which opens the GAP active site to allow Rap binding. Plexin stabilizes the switch II region of Rap in an unprecedented conformation, bringing Gln63 in Rap into the active site for catalyzing GTP hydrolysis. The structures also explain the unique Rap-specificity of plexins. Mutational analyses support that these mechanisms underlie plexin activation and signaling. DOI:http://dx.doi.org/10.7554/eLife.01279.001.
Collapse
Affiliation(s)
- Yuxiao Wang
- Department of Pharmacology , University of Texas Southwestern Medical Center , Dallas , United States
| | | | | | | | | |
Collapse
|
27
|
Futosi K, Fodor S, Mócsai A. Neutrophil cell surface receptors and their intracellular signal transduction pathways. Int Immunopharmacol 2013; 17:638-50. [PMID: 23994464 PMCID: PMC3827506 DOI: 10.1016/j.intimp.2013.06.034] [Citation(s) in RCA: 412] [Impact Index Per Article: 37.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2012] [Revised: 12/07/2012] [Accepted: 06/09/2013] [Indexed: 12/29/2022]
Abstract
Neutrophils play a critical role in the host defense against bacterial and fungal infections, but their inappropriate activation also contributes to tissue damage during autoimmune and inflammatory diseases. Neutrophils express a large number of cell surface receptors for the recognition of pathogen invasion and the inflammatory environment. Those include G-protein-coupled chemokine and chemoattractant receptors, Fc-receptors, adhesion receptors such as selectins/selectin ligands and integrins, various cytokine receptors, as well as innate immune receptors such as Toll-like receptors and C-type lectins. The various cell surface receptors trigger very diverse signal transduction pathways including activation of heterotrimeric and monomeric G-proteins, receptor-induced and store-operated Ca2 + signals, protein and lipid kinases, adapter proteins and cytoskeletal rearrangement. Here we provide an overview of the receptors involved in neutrophil activation and the intracellular signal transduction processes they trigger. This knowledge is crucial for understanding how neutrophils participate in antimicrobial host defense and inflammatory tissue damage and may also point to possible future targets of the pharmacological therapy of neutrophil-mediated autoimmune or inflammatory diseases. Neutrophils are crucial players in innate and adaptive immunity. Neutrophils also participate in autoimmune and inflammatory diseases. Various neutrophil receptors recognize pathogens and the inflammatory environment. The various cell surface receptors trigger diverse intracellular signaling. Neutrophil receptors and signaling are potential targets in inflammatory diseases.
Collapse
Affiliation(s)
- Krisztina Futosi
- Department of Physiology, Semmelweis University School of Medicine, 1094 Budapest, Hungary
| | - Szabina Fodor
- Department of Computer Science, Corvinus University of Budapest, 1093 Budapest, Hungary
| | - Attila Mócsai
- Department of Physiology, Semmelweis University School of Medicine, 1094 Budapest, Hungary
- Corresponding author at: Department of Physiology, Semmelweis University School of Medicine, Tűzoltó utca 37–47, 1094 Budapest, Hungary. Tel.: + 36 1 459 1500x60 409; fax: + 36 1 266 7480.
| |
Collapse
|
28
|
Tsygankova OM, Wang H, Meinkoth JL. Tumor cell migration and invasion are enhanced by depletion of Rap1 GTPase-activating protein (Rap1GAP). J Biol Chem 2013; 288:24636-46. [PMID: 23864657 DOI: 10.1074/jbc.m113.464594] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The functional significance of the widespread down-regulation of Rap1 GTPase-activating protein (Rap1GAP), a negative regulator of Rap activity, in human tumors is unknown. Here we show that human colon cancer cells depleted of Rap1GAP are endowed with more aggressive migratory and invasive properties. Silencing Rap1GAP enhanced the migration of confluent and single cells. In the latter, migration distance, velocity, and directionality were increased. Enhanced migration was a consequence of increased endogenous Rap activity as silencing Rap expression selectively abolished the migration of Rap1GAP-depleted cells. ROCK-mediated cell contractility was suppressed in Rap1GAP-depleted cells, which exhibited a spindle-shaped morphology and abundant membrane protrusions. Tumor cells can switch between Rho/ROCK-mediated contractility-based migration and Rac1-mediated mesenchymal motility. Strikingly, the migration of Rap1GAP-depleted, but not control cells required Rac1 activity, suggesting that loss of Rap1GAP alters migratory mechanisms. Inhibition of Rac1 activity restored membrane blebbing and increased ROCK activity in Rap1GAP-depleted cells, suggesting that Rac1 contributes to the suppression of contractility. Collectively, these findings identify Rap1GAP as a critical regulator of aggressive tumor cell behavior and suggest that the level of Rap1GAP expression influences the migratory mechanisms that are operative in tumor cells.
Collapse
Affiliation(s)
- Oxana M Tsygankova
- Department of Pharmacology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104-6061, USA
| | | | | |
Collapse
|
29
|
Joassard OR, Amirouche A, Gallot YS, Desgeorges MM, Castells J, Durieux AC, Berthon P, Freyssenet DG. Regulation of Akt-mTOR, ubiquitin-proteasome and autophagy-lysosome pathways in response to formoterol administration in rat skeletal muscle. Int J Biochem Cell Biol 2013; 45:2444-55. [PMID: 23916784 DOI: 10.1016/j.biocel.2013.07.019] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Revised: 07/10/2013] [Accepted: 07/24/2013] [Indexed: 10/26/2022]
Abstract
Administration of β2-agonists triggers skeletal muscle anabolism and hypertrophy. We investigated the time course of the molecular events responsible for rat skeletal muscle hypertrophy in response to 1, 3 and 10 days of formoterol administration (i.p. 2000μg/kg/day). A marked hypertrophy of rat tibialis anterior muscle culminated at day 10. Phosphorylation of Akt, ribosomal protein S6, 4E-BP1 and ERK1/2 was increased at day 3, but returned to control level at day 10. This could lead to a transient increase in protein translation and could explain previous studies that reported increase in protein synthesis following β2-agonist administration. Formoterol administration was also associated with a significant reduction in MAFbx/atrogin-1 mRNA level (day 3), suggesting that formoterol can also affect protein degradation of MAFbx/atrogin1 targeted substrates, including MyoD and eukaryotic initiation factor-3f (eIF3-f). Surprisingly, mRNA level of autophagy-related genes, light chain 3 beta (LC3b) and gamma-aminobutyric acid receptor-associated protein-like 1 (Gabarapl1), as well as lysosomal hydrolases, cathepsin B and cathepsin L, was significantly and transiently increased after 1 and/or 3 days, suggesting that autophagosome formation would be increased in response to formoterol administration. However, this has to be relativized since the mRNA level of Unc-51-like kinase1 (Ulk1), BCL2/adenovirus E1B interacting protein3 (Bnip3), and transcription factor EB (TFEB), as well as the protein content of Ulk1, Atg13, Atg5-Atg12 complex and p62/Sqstm1 remained unchanged or was even decreased in response to formoterol administration. These results demonstrate that the effects of formoterol are mediated, in part, through the activation of Akt-mTOR pathway and that other signaling pathways become more important in the regulation of skeletal muscle mass with chronic administration of β2-agonists.
Collapse
Affiliation(s)
- Olivier Roger Joassard
- Laboratoire de Physiologie de l'Exercice, Université de Lyon, F-42023 Saint-Etienne, France
| | | | | | | | | | | | | | | |
Collapse
|
30
|
Abstract
Rap proteins (Rap1, Rap2a, b, c) are small molecular weight GTPases of the Ras family. Rap G proteins mediate diverse cellular events such as cell adhesion, proliferation, and gene activation through various signaling pathways. Activation of Rap signal is regulated tightly by several specific regulatory proteins including guanine nucleotide exchange factors and GTPase-activating proteins. Beyond cell biological studies, increasing attempts have been made in the past decade to define the roles of Rap signal in specific functions of normal tissue systems as well as in cancer. In the immune and hematopoietic systems, Rap signal plays crucial roles in the development and function of essentially all lineages of lymphocytes and hematopoietic cells, and importantly, deregulated Rap signal may lead to unique pathological conditions depending on the affected cell types, including various types of leukemia and autoimmunity. The phenotypical studies have unveiled novel, even unexpected functional aspects of Rap signal in cells from a variety of tissues, providing potentially important clues for controlling human diseases, including malignancy.
Collapse
Affiliation(s)
- Nagahiro Minato
- Department of Immunology and Cell Biology, Graduate School of Medicine, Kyoto University, Kyoto 606-8501, Japan. :
| |
Collapse
|
31
|
Abstract
At synapses, pre- and post-synaptic cells get in direct contact with each other via cell adhesion molecules (CAMs). Several CAMs have been identified at the neuromuscular junction and at central synapses, where they regulate synaptic strength, by recruiting scaffolding proteins, neurotransmitter receptors and synaptic vesicles in response to the binding of counter-receptors across the synaptic cleft. Many synapses are also surrounded by astrocytic processes and embedded in conspicuous extracellular matrix (ECM). It is now widely recognized that astrocytes play a central role in regulating the synaptic machinery by exchanging information with the neuronal elements via diffusible molecules and direct physical interactions; this has lead to the concept of the 'tri-partite synapse'. More recently, the term 'tetra-partite synapse' has been introduced to underlie the importance of ECM in shaping synaptic function by mediating interaction and signaling between neurons and astrocytes. Here, we will review how this integrated view of the synapse can help us understand homeostatic synaptic plasticity at the neuromuscular junction and in the central nervous system. We will explore how synaptic CAMs regulate two forms of homeostatic plasticity: (i) postsynaptic scaling of synaptic currents to counteract changes in neuronal network activity and (ii) the compensatory modulation of presynaptic neurotransmitter release in response to changes in postsynaptic efficacy. We will discuss recent findings on activity-dependent trans-synaptic signaling events and the role of cell adhesion in the feedback control of network activity. This article is part of the Special Issue entitled 'Homeostatic Synaptic Plasticity'.
Collapse
Affiliation(s)
- Agnes Thalhammer
- Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia (IIT), Via Morego 30, 16163 Genoa, Italy
| | - Lorenzo A Cingolani
- Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia (IIT), Via Morego 30, 16163 Genoa, Italy.
| |
Collapse
|
32
|
Yao JF, Shen JZ, Li DK, Lin DS, Li L, Li Q, Qi P, Lian KJ, Ding ZQ. Rap system of stress stimulation can promote bone union after lower tibial bone fracture: a clinical research. Int J Med Sci 2012; 9:462-6. [PMID: 22859907 PMCID: PMC3410366 DOI: 10.7150/ijms.4242] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2012] [Accepted: 07/16/2012] [Indexed: 11/05/2022] Open
Abstract
BACKGROUND Lower tibial bone fracture may easily cause bone delayed union or nonunion because of lacking of dynamic mechanical load. OBJECTIVE Research Group would design a new instrument as Rap System of Stress Stimulation (RSSS) to provide dynamic mechanical load which would promote lower tibial bone union postoperatively. METHODS This clinical research was conducted from January 2008 to December 2010, 92 patients(male 61/female 31, age 16-70 years, mean 36.3 years) who suffered lower tibial bone closed fracture were given intramedullary nail fixation and randomly averagely separated into experimental group and control group(according to the successively order when patients went for the admission procedure). Then researchers analysed the clinical healing time, full weight bearing time, VAS (Visual Analogue Scales) score and callus growth score of Lane-Sandhu in 3,6,12 months postoperatively. The delayed union and nonunion rates were compared at 6 and 12 months separately. RESULTS All the 92 patients had been followed up (mean 14 months). Clinical bone healing time in experimental group was 88.78±8.80 days but control group was 107.91±9.03 days. Full weight bearing time in experimental group was 94.07±9.81 days but control group was 113.24±13.37 days respectively (P<0.05). The delayed union rate in 6 months was 4.3% in experimental group but 10.9% in control group(P<0.05). The nonunion rate in 12 months was 6.5% in experimental group but 19.6% in control group(P<0.05). In 3, 6, 12 months postoperatively, VAS score and Lane-Sandhu score in experimental group had more significantly difference than them in control group. CONCLUSIONS RSSS can intermittently provide dynamic mechanical load and stimulate callus formation, promote lower tibial bone union, reduce bone delayed union or nonunion rate. It is an adjuvant therapy for promoting bone union after lower tibial bone fracture.
Collapse
Affiliation(s)
- Jian-fei Yao
- Department of Orthopaedic Surgery, Affiliated Dongnan Hospital of Xiamen University, Orthopaedic Trauma Center of the 175th Hospital of PLA, Zhangzhou, Fujian, 363000, PR China
| | | | | | | | | | | | | | | | | |
Collapse
|