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Bannoura SF, Khan HY, Uddin MH, Mohammad RM, Pasche BC, Azmi AS. Targeting guanine nucleotide exchange factors for novel cancer drug discovery. Expert Opin Drug Discov 2024; 19:949-959. [PMID: 38884380 DOI: 10.1080/17460441.2024.2368242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Accepted: 06/10/2024] [Indexed: 06/18/2024]
Abstract
INTRODUCTION Guanine nucleotide exchange factors (GEFs) regulate the activation of small GTPases (G proteins) of the Ras superfamily proteins controlling cellular functions. Ras superfamily proteins act as 'molecular switches' that are turned 'ON' by guanine exchange. There are five major groups of Ras family GTPases: Ras, Ran, Rho, Rab and Arf, with a variety of different GEFs regulating their GTP loading. GEFs have been implicated in various diseases including cancer. This makes GEFs attractive targets to modulate signaling networks controlled by small GTPases. AREAS COVERED In this review, the roles and mechanisms of GEFs in malignancy are outlined. The mechanism of guanine exchange activity by GEFs on a small GTPase is illustrated. Then, some examples of GEFs that are significant in cancer are presented with a discussion on recent progress in therapeutic targeting efforts using a variety of approaches. EXPERT OPINION Recently, GEFs have emerged as potential therapeutic targets for novel cancer drug development. Targeting small GTPases is challenging; thus, targeting their activation by GEFs is a promising strategy. Most GEF-targeted drugs are still in preclinical development. A deeper biological understanding of the underlying mechanisms of GEF activity and utilizing advanced technology are necessary to enhance drug discovery for GEFs in cancer.
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Affiliation(s)
- Sahar F Bannoura
- Department of Oncology, Karmanos Cancer Institute, Wayne State University School of Medicine, Detroit, MI, USA
| | - Husain Yar Khan
- Department of Oncology, Karmanos Cancer Institute, Wayne State University School of Medicine, Detroit, MI, USA
| | - Md Hafiz Uddin
- Department of Oncology, Karmanos Cancer Institute, Wayne State University School of Medicine, Detroit, MI, USA
| | - Ramzi M Mohammad
- Department of Oncology, Karmanos Cancer Institute, Wayne State University School of Medicine, Detroit, MI, USA
| | - Boris C Pasche
- Department of Oncology, Karmanos Cancer Institute, Wayne State University School of Medicine, Detroit, MI, USA
| | - Asfar S Azmi
- Department of Oncology, Karmanos Cancer Institute, Wayne State University School of Medicine, Detroit, MI, USA
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Iglesia RP, Prado MB, Alves RN, Escobar MIM, Fernandes CFDL, Fortes ACDS, Souza MCDS, Boccacino JM, Cangiano G, Soares SR, de Araújo JPA, Tiek DM, Goenka A, Song X, Keady JR, Hu B, Cheng SY, Lopes MH. Unconventional Protein Secretion in Brain Tumors Biology: Enlightening the Mechanisms for Tumor Survival and Progression. Front Cell Dev Biol 2022; 10:907423. [PMID: 35784465 PMCID: PMC9242006 DOI: 10.3389/fcell.2022.907423] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 05/26/2022] [Indexed: 11/28/2022] Open
Abstract
Non-canonical secretion pathways, collectively known as unconventional protein secretion (UPS), are alternative secretory mechanisms usually associated with stress-inducing conditions. UPS allows proteins that lack a signal peptide to be secreted, avoiding the conventional endoplasmic reticulum-Golgi complex secretory pathway. Molecules that generally rely on the canonical pathway to be secreted may also use the Golgi bypass, one of the unconventional routes, to reach the extracellular space. UPS studies have been increasingly growing in the literature, including its implication in the biology of several diseases. Intercellular communication between brain tumor cells and the tumor microenvironment is orchestrated by various molecules, including canonical and non-canonical secreted proteins that modulate tumor growth, proliferation, and invasion. Adult brain tumors such as gliomas, which are aggressive and fatal cancers with a dismal prognosis, could exploit UPS mechanisms to communicate with their microenvironment. Herein, we provide functional insights into the UPS machinery in the context of tumor biology, with a particular focus on the secreted proteins by alternative routes as key regulators in the maintenance of brain tumors.
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Affiliation(s)
- Rebeca Piatniczka Iglesia
- Laboratory of Neurobiology and Stem Cells, Department of Cell and Developmental Biology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil,The Robert H. Lurie Comprehensive Cancer Center, The Ken and Ruth Davee Department of Neurology, Lou and Jean Malnati Brain Tumor Institute at Northwestern Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, United States
| | - Mariana Brandão Prado
- Laboratory of Neurobiology and Stem Cells, Department of Cell and Developmental Biology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Rodrigo Nunes Alves
- Laboratory of Neurobiology and Stem Cells, Department of Cell and Developmental Biology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Maria Isabel Melo Escobar
- Laboratory of Neurobiology and Stem Cells, Department of Cell and Developmental Biology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Camila Felix de Lima Fernandes
- Laboratory of Neurobiology and Stem Cells, Department of Cell and Developmental Biology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Ailine Cibele dos Santos Fortes
- Laboratory of Neurobiology and Stem Cells, Department of Cell and Developmental Biology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Maria Clara da Silva Souza
- Laboratory of Neurobiology and Stem Cells, Department of Cell and Developmental Biology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Jacqueline Marcia Boccacino
- Laboratory of Neurobiology and Stem Cells, Department of Cell and Developmental Biology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Giovanni Cangiano
- Laboratory of Neurobiology and Stem Cells, Department of Cell and Developmental Biology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Samuel Ribeiro Soares
- Laboratory of Neurobiology and Stem Cells, Department of Cell and Developmental Biology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - João Pedro Alves de Araújo
- Laboratory of Neurobiology and Stem Cells, Department of Cell and Developmental Biology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Deanna Marie Tiek
- The Robert H. Lurie Comprehensive Cancer Center, The Ken and Ruth Davee Department of Neurology, Lou and Jean Malnati Brain Tumor Institute at Northwestern Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, United States
| | - Anshika Goenka
- The Robert H. Lurie Comprehensive Cancer Center, The Ken and Ruth Davee Department of Neurology, Lou and Jean Malnati Brain Tumor Institute at Northwestern Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, United States
| | - Xiao Song
- The Robert H. Lurie Comprehensive Cancer Center, The Ken and Ruth Davee Department of Neurology, Lou and Jean Malnati Brain Tumor Institute at Northwestern Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, United States
| | - Jack Ryan Keady
- The Robert H. Lurie Comprehensive Cancer Center, The Ken and Ruth Davee Department of Neurology, Lou and Jean Malnati Brain Tumor Institute at Northwestern Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, United States
| | - Bo Hu
- The Robert H. Lurie Comprehensive Cancer Center, The Ken and Ruth Davee Department of Neurology, Lou and Jean Malnati Brain Tumor Institute at Northwestern Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, United States
| | - Shi Yuan Cheng
- The Robert H. Lurie Comprehensive Cancer Center, The Ken and Ruth Davee Department of Neurology, Lou and Jean Malnati Brain Tumor Institute at Northwestern Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, United States
| | - Marilene Hohmuth Lopes
- Laboratory of Neurobiology and Stem Cells, Department of Cell and Developmental Biology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil,*Correspondence: Marilene Hohmuth Lopes,
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Lacerda ÍCDS, Polonio JC, Golias HC. Endophytic Fungi as a Source of Antiviral Compounds - A Review. Chem Biodivers 2022; 19:e202100971. [PMID: 35426966 DOI: 10.1002/cbdv.202100971] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Accepted: 04/14/2022] [Indexed: 11/05/2022]
Abstract
Endophytic fungi are a rich source of secondary metabolites. The interactions between endophytes and their hosts lead to the production of several bioactive substances grouped into different classes, each having a wide variety of effects against various pathogens. The metabolites obtained from these organisms include steroids, alkaloids, phenols, isocoumarins, xanthones, quinones, and terpenoids, among others. These substances are known to have antibiotic, antiparasitic, antifungal, and antiviral effects. This review summarizes secondary metabolites with antiviral effects produced by endophytic fungi and highlights the importance of research in developing novel antiviral substances. We demonstrate that endophytic fungi are a rich source of secondary metabolites that combat pathologies caused by viruses. Optimizing practical and biotechnological screening tools for the research of these metabolites will provide promising drugs to combat these infections.
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Affiliation(s)
| | - Júlio Cesar Polonio
- Department of Cell Biology, Genetics and Biotechnology, State University of Maringá (UEM), Brazil
| | - Halison Correia Golias
- Department of Humanities, Microbiology Laboratory, Federal Technological University of Paraná (UTFPR), Brazil
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Zou YJ, Shan MM, Pan ZN, Pan MH, Li XH, Sun SC. Loss of Arf Guanine Nucleotide Exchange Factor GBF1 Activity Disturbs Organelle Dynamics in Mouse Oocytes. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2021; 27:400-408. [PMID: 33478608 DOI: 10.1017/s1431927620024885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
GBF1 [Golgi brefeldin A (BFA) resistance factor 1] is a member of the guanine nucleotide exchange factors Arf family. GBF1 localizes at the cis-Golgi and endoplasmic reticulum (ER)-Golgi intermediate compartment where it participates in ER-Golgi traffic by assisting in the recruitment of the coat protein COPI. However, the roles of GBF1 in oocyte meiotic maturation are still unknown. In the present study, we investigated the regulatory functions of GBF1 in mouse oocyte organelle dynamics. In our results, GBF1 was stably expressed during oocyte maturation, and GBF1 localized at the spindle periphery during metaphase I. Inhibiting GBF1 activity led to aberrant accumulation of the Golgi apparatus around the spindle. This may be due to the effects of GBF1 on the localization of GM130, as GBF1 co-localized with GM130 and inhibiting GBF1 induced condensation of GM130. Moreover, the loss of GBF1 activity affected the ER distribution and induced ER stress, as shown by increased GRP78 expression. Mitochondrial localization and functions were affected, as the mitochondrial membrane potential was altered. Taken together, these results suggest that GBF1 has wide-ranging effects on the distribution and functions of Golgi apparatus, ER, and mitochondria as well as normal polar body formation in mouse oocytes.
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Affiliation(s)
- Yuan-Jing Zou
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing210095, China
| | - Meng-Meng Shan
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing210095, China
| | - Zhen-Nan Pan
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing210095, China
| | - Meng-Hao Pan
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing210095, China
| | - Xiao-Han Li
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing210095, China
| | - Shao-Chen Sun
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing210095, China
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Lorimer IAJ. Aberrant Rac pathway signalling in glioblastoma. Small GTPases 2021; 12:81-95. [PMID: 31032735 PMCID: PMC7849730 DOI: 10.1080/21541248.2019.1612694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Revised: 04/23/2019] [Accepted: 04/25/2019] [Indexed: 10/26/2022] Open
Abstract
Glioblastoma is an aggressive and incurable form of brain cancer. Both mutation analysis in human glioblastoma and mouse modelling studies have shown that aberrant activation of the PI 3-kinase pathway is a central driver of glioblastoma malignancy. The small GTPase Rac is activated downstream of this pathway, mediating a subset of the effects of aberrant PI 3-kinase pathway activation. Here I discuss the current state of our knowledge on Rac activation mechanisms in glioblastoma. Current knowledge on roles for specific PI 3-kinase pathway responsive Rac guanine nucleotide exchange factors in glioblastoma is reviewed. Rac is best known for its role in promoting cell motility and invasion, but there is also evidence for roles in multiple other cellular processes with cancer relevance, including proliferation, differentiation, apoptosis, DNA damage responses, metabolism, angiogenesis and immunosuppression. I review what is known about the role of Rac in these processes in glioblastoma. Finally, I assess possible strategies to inhibit this pathway in glioblastoma through either direct inhibition of Rac or inhibition of upstream activators or downstream mediators of Rac signalling.
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Affiliation(s)
- Ian AJ Lorimer
- Cancer Therapeutics Program, Ottawa Hospital Research Institute, Ottawa, Canada
- Department of Medicine, University of Ottawa, Ottawa, Ontario, Canada
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Ontario, Canada
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Bello-Perez M, Sola I, Novoa B, Klionsky DJ, Falco A. Canonical and Noncanonical Autophagy as Potential Targets for COVID-19. Cells 2020; 9:E1619. [PMID: 32635598 PMCID: PMC7408018 DOI: 10.3390/cells9071619] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 06/29/2020] [Accepted: 07/01/2020] [Indexed: 02/06/2023] Open
Abstract
The SARS-CoV-2 pandemic necessitates a review of the molecular mechanisms underlying cellular infection by coronaviruses, in order to identify potential therapeutic targets against the associated new disease (COVID-19). Previous studies on its counterparts prove a complex and concomitant interaction between coronaviruses and autophagy. The precise manipulation of this pathway allows these viruses to exploit the autophagy molecular machinery while avoiding its protective apoptotic drift and cellular innate immune responses. In turn, the maneuverability margins of such hijacking appear to be so narrow that the modulation of the autophagy, regardless of whether using inducers or inhibitors (many of which are FDA-approved for the treatment of other diseases), is usually detrimental to viral replication, including SARS-CoV-2. Recent discoveries indicate that these interactions stretch into the still poorly explored noncanonical autophagy pathway, which might play a substantial role in coronavirus replication. Still, some potential therapeutic targets within this pathway, such as RAB9 and its interacting proteins, look promising considering current knowledge. Thus, the combinatory treatment of COVID-19 with drugs affecting both canonical and noncanonical autophagy pathways may be a turning point in the fight against this and other viral infections, which may also imply beneficial prospects of long-term protection.
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Affiliation(s)
- Melissa Bello-Perez
- Department of Molecular and Cell Biology, National Center of Biotechnology (CNB-CSIC), Campus Universidad Autónoma de Madrid, Darwin 3, 28049 Madrid, Spain; (M.B.-P.); (I.S.)
| | - Isabel Sola
- Department of Molecular and Cell Biology, National Center of Biotechnology (CNB-CSIC), Campus Universidad Autónoma de Madrid, Darwin 3, 28049 Madrid, Spain; (M.B.-P.); (I.S.)
| | - Beatriz Novoa
- Institute of Marine Research (IIM), National Research Council (CSIC), 36208 Vigo, Spain;
| | - Daniel J. Klionsky
- Life Sciences Institute and Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA;
| | - Alberto Falco
- Institute of Research, Development, and Innovation in Healthcare Biotechnology in Elche (IDiBE), Miguel Hernández University (UMH), 03202 Elche, Spain
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Luesch H, Paavilainen VO. Natural products as modulators of eukaryotic protein secretion. Nat Prod Rep 2020; 37:717-736. [PMID: 32067014 DOI: 10.1039/c9np00066f] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Covering: up to the end of 2019Diverse natural product small molecules have allowed critical insights into processes that govern eukaryotic cells' ability to secrete cytosolically synthesized secretory proteins into their surroundings or to insert newly synthesized integral membrane proteins into the lipid bilayer of the endoplasmic reticulum. In addition, many components of the endoplasmic reticulum, required for protein homeostasis or other processes such as lipid metabolism or maintenance of calcium homeostasis, are being investigated for their potential in modulating human disease conditions such as cancer, neurodegenerative conditions and diabetes. In this review, we cover recent findings up to the end of 2019 on natural products that influence protein secretion or impact ER protein homeostasis, and serve as powerful chemical tools to understand protein flux through the mammalian secretory pathway and as leads for the discovery of new therapeutics.
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Affiliation(s)
- Hendrik Luesch
- Department of Medicinal Chemistry, Center for Natural Products, Drug Discovery and Development (CNPD3), University of Florida, P.O. Box 100485, Gainesville, Florida 32610, USA.
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Pipaliya SV, Schlacht A, Klinger CM, Kahn RA, Dacks J. Ancient complement and lineage-specific evolution of the Sec7 ARF GEF proteins in eukaryotes. Mol Biol Cell 2019; 30:1846-1863. [PMID: 31141460 PMCID: PMC6727740 DOI: 10.1091/mbc.e19-01-0073] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Guanine nucleotide exchange factors (GEFs) are the initiators of signaling by every regulatory GTPase, which in turn act to regulate a wide array of essential cellular processes. To date, each family of GTPases is activated by distinct families of GEFs. Bidirectional membrane trafficking is regulated by ADP-ribosylation factor (ARF) GTPases and the development throughout eukaryotic evolution of increasingly complex systems of such traffic required the acquisition of a functionally diverse cohort of ARF GEFs to control it. We performed phylogenetic analyses of ARF GEFs in eukaryotes, defined by the presence of the Sec7 domain, and found three subfamilies (BIG, GBF1, and cytohesins) to have been present in the ancestor of all eukaryotes. The four other subfamilies (EFA6/PSD, IQSEC7/BRAG, FBX8, and TBS) are opisthokont, holozoan, metazoan, and alveolate/haptophyte specific, respectively, and each is derived from cytohesins. We also identified a cytohesin-derived subfamily, termed ankyrin repeat-containing cytohesin, that independently evolved in amoebozoans and members of the SAR and haptophyte clades. Building on evolutionary data for the ARF family GTPases and their GTPase--activating proteins allowed the generation of hypotheses about ARF GEF protein function(s) as well as a better understanding of the origins and evolution of cellular complexity in eukaryotes.
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Affiliation(s)
- Shweta V Pipaliya
- Department of Medicine, Division of Infectious Diseases, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2S2, Canada
| | - Alexander Schlacht
- Department of Medicine, Division of Infectious Diseases, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2S2, Canada
| | - Christen M Klinger
- Department of Medicine, Division of Infectious Diseases, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2S2, Canada
| | - Richard A Kahn
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322
| | - Joel Dacks
- Department of Medicine, Division of Infectious Diseases, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2S2, Canada.,Department of Life Sciences, The Natural History Museum, London SW7 5BD, United Kingdom
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Dee RA, Mangum KD, Bai X, Mack CP, Taylor JM. Druggable targets in the Rho pathway and their promise for therapeutic control of blood pressure. Pharmacol Ther 2019; 193:121-134. [PMID: 30189292 PMCID: PMC7235948 DOI: 10.1016/j.pharmthera.2018.09.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The prevalence of high blood pressure (also known as hypertension) has steadily increased over the last few decades. Known as a silent killer, hypertension increases the risk for cardiovascular disease and can lead to stroke, heart attack, kidney failure and associated sequela. While numerous hypertensive therapies are currently available, it is estimated that only half of medicated patients exhibit blood pressure control. This signifies the need for a better understanding of the underlying cause of disease and for more effective therapies. While blood pressure homeostasis is very complex and involves the integrated control of multiple body systems, smooth muscle contractility and arterial resistance are important contributors. Strong evidence from pre-clinical animal models and genome-wide association studies indicate that smooth muscle contraction and BP homeostasis are governed by the small GTPase RhoA and its downstream target, Rho kinase. In this review, we summarize the signaling pathways and regulators that impart tight spatial-temporal control of RhoA activity in smooth muscle cells and discuss current therapeutic strategies to target these RhoA pathway components. We also discuss known allelic variations in the RhoA pathway and consider how these polymorphisms may affect genetic risk for hypertension and its clinical manifestations.
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Affiliation(s)
- Rachel A Dee
- Department of Pathology and Laboratory Medicine, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Kevin D Mangum
- Department of Pathology and Laboratory Medicine, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Xue Bai
- Department of Pathology and Laboratory Medicine, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Christopher P Mack
- Department of Pathology and Laboratory Medicine, University of North Carolina, Chapel Hill, NC 27599, USA; McAllister Heart Institute, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Joan M Taylor
- Department of Pathology and Laboratory Medicine, University of North Carolina, Chapel Hill, NC 27599, USA; McAllister Heart Institute, University of North Carolina, Chapel Hill, NC 27599, USA.
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Alborzinia H, Ignashkova TI, Dejure FR, Gendarme M, Theobald J, Wölfl S, Lindemann RK, Reiling JH. Golgi stress mediates redox imbalance and ferroptosis in human cells. Commun Biol 2018; 1:210. [PMID: 30511023 PMCID: PMC6262011 DOI: 10.1038/s42003-018-0212-6] [Citation(s) in RCA: 93] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Accepted: 11/05/2018] [Indexed: 12/15/2022] Open
Abstract
Cytotoxic activities of several Golgi-dispersing compounds including AMF-26/M-COPA, brefeldin A and golgicide A have previously been shown to induce autophagy or apoptosis. Here, we demonstrate that these Golgi disruptors also trigger ferroptosis, a non-apoptotic form of cell death characterized by iron-dependent oxidative degradation of lipids. Inhibitors of ferroptosis not only counteract cell death, but they also protect from Golgi dispersal and inhibition of protein secretion in response to several Golgi stress agents. Furthermore, the application of sublethal doses of ferroptosis-inducers such as erastin and sorafenib, low cystine growth conditions, or genetic knockdown of SLC7A11 and GPX4 all similarly protect cells from Golgi stress and lead to modulation of ACSL4, SLC7A5, SLC7A11 or GPX4 levels. Collectively, this study suggests a previously unrecognized function of the Golgi apparatus, which involves cellular redox control and prevents ferroptotic cell death. Hamed Alborzinia et al. show that Golgi-dispersing compounds trigger iron-dependent oxidative degradation of lipids, inducing a non-apoptotic cell death called ferroptosis. This study provides insight into the role of Golgi apparatus for preventing ferroptotic cell death through its cellular redox control.
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Affiliation(s)
- Hamed Alborzinia
- BioMed X Innovation Center, Im Neuenheimer Feld 583, 69120 Heidelberg, Germany.,4Present Address: Division of Stem Cells and Cancer, German Cancer Research Center (DKFZ) and Heidelberg Institute for Stem Cell Technology and Experimental Medicine (HI-STEM), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | | | - Francesca R Dejure
- BioMed X Innovation Center, Im Neuenheimer Feld 583, 69120 Heidelberg, Germany
| | - Mathieu Gendarme
- BioMed X Innovation Center, Im Neuenheimer Feld 583, 69120 Heidelberg, Germany
| | - Jannick Theobald
- 2Institute of Pharmacy and Molecular Biotechnology, Heidelberg University, Im Neuenheimer Feld 364, 69120 Heidelberg, Germany
| | - Stefan Wölfl
- 2Institute of Pharmacy and Molecular Biotechnology, Heidelberg University, Im Neuenheimer Feld 364, 69120 Heidelberg, Germany
| | - Ralph K Lindemann
- 3Translational Innovation Platform Oncology, Merck Biopharma, Merck KGaA, Frankfurter Str. 250, 64293 Darmstadt, Germany
| | - Jan H Reiling
- BioMed X Innovation Center, Im Neuenheimer Feld 583, 69120 Heidelberg, Germany.,5Present Address: Institute for Applied Cancer Science and Center for Co-Clinical Trials, University of Texas MD Anderson Cancer Center, Houston, TX USA
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Luchsinger C, Aguilar M, Burgos PV, Ehrenfeld P, Mardones GA. Functional disruption of the Golgi apparatus protein ARF1 sensitizes MDA-MB-231 breast cancer cells to the antitumor drugs Actinomycin D and Vinblastine through ERK and AKT signaling. PLoS One 2018; 13:e0195401. [PMID: 29614107 PMCID: PMC5882166 DOI: 10.1371/journal.pone.0195401] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2017] [Accepted: 03/21/2018] [Indexed: 12/26/2022] Open
Abstract
Increasing evidence indicates that the Golgi apparatus plays active roles in cancer, but a comprehensive understanding of its functions in the oncogenic transformation has not yet emerged. At the same time, the Golgi is becoming well recognized as a hub that integrates its functions of protein and lipid biosynthesis to signal transduction for cell proliferation and migration in cancer cells. Nevertheless, the active function of the Golgi apparatus in cancer cells has not been fully evaluated as a target for combined treatment. Here, we analyzed the effect of perturbing the Golgi apparatus on the sensitivity of the MDA-MB-231 breast cancer cell line to the drugs Actinomycin D and Vinblastine. We disrupted the function of ARF1, a protein necessary for the homeostasis of the Golgi apparatus. We found that the expression of the ARF1-Q71L mutant increased the sensitivity of MDA-MB-231 cells to both Actinomycin D and Vinblastine, resulting in decreased cell proliferation and cell migration, as well as in increased apoptosis. Likewise, the combined treatment of cells with Actinomycin D or Vinblastine and Brefeldin A or Golgicide A, two disrupting agents of the ARF1 function, resulted in similar effects on cell proliferation, cell migration and apoptosis. Interestingly, each combined treatment had distinct effects on ERK1/2 and AKT signaling, as indicated by the decreased levels of either phospho-ERK1/2 or phospho-AKT. Our results suggest that disruption of Golgi function could be used as a strategy for the sensitization of cancer cells to chemotherapy.
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Affiliation(s)
- Charlotte Luchsinger
- Department of Physiology, School of Medicine, Universidad Austral de Chile, Valdivia, Chile
- Center for Interdisciplinary Studies of the Nervous System (CISNe), Universidad Austral de Chile, Valdivia, Chile
| | - Marcelo Aguilar
- Department of Physiology, School of Medicine, Universidad Austral de Chile, Valdivia, Chile
- Center for Interdisciplinary Studies of the Nervous System (CISNe), Universidad Austral de Chile, Valdivia, Chile
| | - Patricia V. Burgos
- Department of Physiology, School of Medicine, Universidad Austral de Chile, Valdivia, Chile
- Center for Interdisciplinary Studies of the Nervous System (CISNe), Universidad Austral de Chile, Valdivia, Chile
- Center for Cell Biology and Biomedicine (CEBICEM), School of Medicine and Science, Universidad San Sebastián, Santiago, Chile
- Center for Aging and Regeneration (CARE), Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Pamela Ehrenfeld
- Center for Interdisciplinary Studies of the Nervous System (CISNe), Universidad Austral de Chile, Valdivia, Chile
- Department of Anatomy, Histology and Pathology, School of Medicine, Universidad Austral de Chile, Valdivia, Chile
| | - Gonzalo A. Mardones
- Department of Physiology, School of Medicine, Universidad Austral de Chile, Valdivia, Chile
- Center for Interdisciplinary Studies of the Nervous System (CISNe), Universidad Austral de Chile, Valdivia, Chile
- Center for Cell Biology and Biomedicine (CEBICEM), School of Medicine and Science, Universidad San Sebastián, Santiago, Chile
- * E-mail:
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Ignashkova TI, Gendarme M, Peschk K, Eggenweiler HM, Lindemann RK, Reiling JH. Cell survival and protein secretion associated with Golgi integrity in response to Golgi stress-inducing agents. Traffic 2017; 18:530-544. [PMID: 28485883 DOI: 10.1111/tra.12493] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Revised: 05/05/2017] [Accepted: 05/05/2017] [Indexed: 12/29/2022]
Abstract
The Golgi apparatus is part of the secretory pathway and of central importance for modification, transport and sorting of proteins and lipids. ADP-ribosylation factors, whose activation can be blocked by brefeldin A (BFA), play a major role in functioning of the Golgi network and regulation of membrane traffic and are also involved in proliferation and migration of cancer cells. Due to high cytotoxicity and poor bioavailability, BFA has not passed the preclinical stage of drug development. Recently, AMF-26 and golgicide A have been described as novel inhibitors of the Golgi system with antitumor or bactericidal properties. We provide here further evidence that AMF-26 closely mirrors the mode of action of BFA but is less potent. Using several human cancer cell lines, we studied the effects of AMF-26, BFA and golgicide A on cell homeostasis including Golgi structure, endoplasmic reticulum (ER) stress markers, secretion and viability, and found overall a significant correlation between these parameters. Furthermore, modulation of ADP-ribosylation factor expression has a profound impact on Golgi organization and survival in response to Golgi stress inducers.
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Affiliation(s)
- Tatiana I Ignashkova
- Metabolism and Signaling in Cancer, BioMed X Innovation Center, Heidelberg, Germany
| | - Mathieu Gendarme
- Metabolism and Signaling in Cancer, BioMed X Innovation Center, Heidelberg, Germany
| | - Katrin Peschk
- Medicinal Chemistry, Merck Biopharma, Merck KGaA, Darmstadt, Germany
| | | | - Ralph K Lindemann
- Translational Innovation Platform Oncology, Merck Biopharma, Merck KGaA, Darmstadt, Germany
| | - Jan H Reiling
- Metabolism and Signaling in Cancer, BioMed X Innovation Center, Heidelberg, Germany
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13
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Rafiq NBM, Lieu ZZ, Jiang T, Yu CH, Matsudaira P, Jones GE, Bershadsky AD. Podosome assembly is controlled by the GTPase ARF1 and its nucleotide exchange factor ARNO. J Cell Biol 2016; 216:181-197. [PMID: 28007915 PMCID: PMC5223603 DOI: 10.1083/jcb.201605104] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Revised: 09/26/2016] [Accepted: 11/28/2016] [Indexed: 01/07/2023] Open
Abstract
Podosomes represent a class of integrin-mediated cell-matrix adhesions formed by migrating and matrix-degrading cells. We demonstrate that in macrophage-like THP1 cells and fibroblasts stimulated to produce podosomes, down-regulation of the G-protein ARF1 or the ARF1 guanine nucleotide exchange factor, ARNO, by small, interfering RNA or pharmacological inhibitors led to striking podosome elimination. Concomitantly, treatments inducing podosome formation increased the level of guanosine triphosphate (GTP)-bound ARF1. ARNO was found to colocalize with the adhesive rings of podosomes, whereas ARF1 was localized to vesicular structures transiently contacting podosome rings. Inhibition of ARF1 led to an increase in RhoA-GTP levels and triggered assembly of myosin-IIA filaments in THP1 cells, whereas the suppression of myosin-IIA rescued podosome formation regardless of ARF1 inhibition. Finally, expression of constitutively active ARF1 in fibroblasts induced formation of putative podosome precursors: actin-rich puncta coinciding with matrix degradation sites and containing proteins of the podosome core but not of the adhesive ring. Thus, ARNO-ARF1 regulates formation of podosomes by inhibition of RhoA/myosin-II and promotion of actin core assembly.
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Affiliation(s)
- Nisha Bte Mohd Rafiq
- Mechanobiology Institute, National University of Singapore, Singapore 117411, Singapore.,Department of Biological Sciences, National University of Singapore, Singapore 117543, Singapore.,Randall Division of Cell and Molecular Biophysics, King's College London, London SE1 1UL, England, UK
| | - Zi Zhao Lieu
- Mechanobiology Institute, National University of Singapore, Singapore 117411, Singapore.,Department of Biological Sciences, National University of Singapore, Singapore 117543, Singapore
| | - Tingting Jiang
- Mechanobiology Institute, National University of Singapore, Singapore 117411, Singapore
| | - Cheng-Han Yu
- Mechanobiology Institute, National University of Singapore, Singapore 117411, Singapore
| | - Paul Matsudaira
- Mechanobiology Institute, National University of Singapore, Singapore 117411, Singapore.,Department of Biological Sciences, National University of Singapore, Singapore 117543, Singapore
| | - Gareth E Jones
- Randall Division of Cell and Molecular Biophysics, King's College London, London SE1 1UL, England, UK
| | - Alexander D Bershadsky
- Mechanobiology Institute, National University of Singapore, Singapore 117411, Singapore .,Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 76100, Israel
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14
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Mishra AK, Lambright DG. Invited review: Small GTPases and their GAPs. Biopolymers 2016; 105:431-48. [PMID: 26972107 PMCID: PMC5439442 DOI: 10.1002/bip.22833] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Revised: 02/16/2016] [Accepted: 03/10/2016] [Indexed: 12/11/2022]
Abstract
Widespread utilization of small GTPases as major regulatory hubs in many different biological systems derives from a conserved conformational switch mechanism that facilitates cycling between GTP-bound active and GDP-bound inactive states under control of guanine nucleotide exchange factors (GEFs) and GTPase activating proteins (GAPs), which accelerate slow intrinsic rates of activation by nucleotide exchange and deactivation by GTP hydrolysis, respectively. Here we review developments leading to current understanding of intrinsic and GAP catalyzed GTP hydrolytic reactions in small GTPases from structural, molecular and chemical mechanistic perspectives. Despite the apparent simplicity of the GTPase cycle, the structural bases underlying the hallmark hydrolytic reaction and catalytic acceleration by GAPs are considerably more diverse than originally anticipated. Even the most fundamental aspects of the reaction mechanism have been challenging to decipher. Through a combination of experimental and in silico approaches, the outlines of a consensus view have begun to emerge for the best studied paradigms. Nevertheless, recent observations indicate that there is still much to be learned. © 2016 Wiley Periodicals, Inc. Biopolymers 105: 431-448, 2016.
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Affiliation(s)
- Ashwini K Mishra
- Program in Molecular Medicine and Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA, 01605
| | - David G Lambright
- Program in Molecular Medicine and Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA, 01605
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15
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Seifert W, Posor Y, Schu P, Stenbeck G, Mundlos S, Klaassen S, Nürnberg P, Haucke V, Kornak U, Kühnisch J. The progressive ankylosis protein ANK facilitates clathrin- and adaptor-mediated membrane traffic at the trans-Golgi network-to-endosome interface. Hum Mol Genet 2016; 25:3836-3848. [PMID: 27466194 DOI: 10.1093/hmg/ddw230] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2016] [Revised: 07/01/2016] [Accepted: 07/01/2016] [Indexed: 12/19/2022] Open
Abstract
Dominant or recessive mutations in the progressive ankylosis gene ANKH have been linked to familial chondrocalcinosis (CCAL2), craniometaphyseal dysplasia (CMD), mental retardation, deafness and ankylosis syndrome (MRDA). The function of the encoded membrane protein ANK in cellular compartments other than the plasma membrane is unknown. Here, we show that ANK localizes to the trans-Golgi network (TGN), clathrin-coated vesicles and the plasma membrane. ANK functionally interacts with clathrin and clathrin associated adaptor protein (AP) complexes as loss of either protein causes ANK dispersion from the TGN to cytoplasmic endosome-like puncta. Consistent with its subcellular localization, loss of ANK results in reduced formation of tubular membrane carriers from the TGN, perinuclear accumulation of early endosomes and impaired transferrin endocytosis. Our data indicate that clathrin/AP-mediated cycling of ANK between the TGN, endosomes, and the cell surface regulates membrane traffic at the TGN/endosomal interface. These findings suggest that dysfunction of Golgi-endosomal membrane traffic may contribute to ANKH-associated pathologies.
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Affiliation(s)
- Wenke Seifert
- Institute of Vegetative Anatomy, Charité - Universitätsmedizin Berlin, Germany
| | - York Posor
- Department of Molecular Pharmacology and Cell Biology, Leibniz-Institut für Molekulare Pharmakologie (FMP), Berlin, Germany
| | - Peter Schu
- Department of Cellular Biochemistry, Universitätsmedizin Georg-August University, Göttingen, Germany
| | - Gudrun Stenbeck
- College of Health and Life Sciences, Brunel University, Uxbridge, United Kingdom
| | - Stefan Mundlos
- Institute for Medical and Human Genetics, Charité - Universitätsmedizin Berlin, Germany.,FG Development and Disease, Max-Planck-Institute for Molecular Genetics, Berlin, Germany.,Berlin-Brandenburg Center for Regenerative Therapies, Charité - Universitätsmedizin Berlin, Germany
| | - Sabine Klaassen
- Experimental and Clinical Research Center (ECRC)
- Max-Delbrück-Centrum for Molecular Medicine (MDC), Charité - Universitätsmedizin Berlin, Berlin, Germany.,Department of Pediatric Cardiology, Charité - Universitätsmedizin Berlin, Germany and
| | - Peter Nürnberg
- Cologne Center for Genomics (CCG), University of Cologne, Germany
| | - Volker Haucke
- Department of Molecular Pharmacology and Cell Biology, Leibniz-Institut für Molekulare Pharmakologie (FMP), Berlin, Germany
| | - Uwe Kornak
- Institute for Medical and Human Genetics, Charité - Universitätsmedizin Berlin, Germany.,FG Development and Disease, Max-Planck-Institute for Molecular Genetics, Berlin, Germany.,Berlin-Brandenburg Center for Regenerative Therapies, Charité - Universitätsmedizin Berlin, Germany
| | - Jirko Kühnisch
- Institute for Medical and Human Genetics, Charité - Universitätsmedizin Berlin, Germany .,FG Development and Disease, Max-Planck-Institute for Molecular Genetics, Berlin, Germany.,Experimental and Clinical Research Center (ECRC)
- Max-Delbrück-Centrum for Molecular Medicine (MDC), Charité - Universitätsmedizin Berlin, Berlin, Germany
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16
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Abstract
Two topics that have attracted recent attention in the field of autophagy concern the source of the membrane that is used to form the autophagosome during macroautophagy and the role of noncanonical autophagic pathways. The 2 topics may converge when considering the intersection of autophagy with viral infection. We suggest that noncanonical autophagy, which is sensitive to treatment with brefeldin A, may converge with the infectious cycles of certain DNA and RNA viruses that utilize membrane from the ER and cis-Golgi.
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Affiliation(s)
- Charles Grose
- a University of Iowa , Children's Hospital , Iowa City , IA , USA
| | - Daniel J Klionsky
- b Life Sciences Institute, University of Michigan , Ann Arbor , MI , USA
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17
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Doyle SM, Vain T, Robert S. Small molecules unravel complex interplay between auxin biology and endomembrane trafficking. JOURNAL OF EXPERIMENTAL BOTANY 2015; 66:4971-82. [PMID: 25911743 DOI: 10.1093/jxb/erv179] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The establishment and maintenance of controlled auxin gradients within plant tissues are essential for a multitude of developmental processes. Auxin gradient formation is co-ordinated via local biosynthesis and transport. Cell to cell auxin transport is facilitated and precisely regulated by complex endomembrane trafficking mechanisms that target auxin carrier proteins to their final destinations. In turn, auxin and cross-talk with other phytohormones regulate the endomembrane trafficking of auxin carriers. Dissecting such rapid and complicated processes is challenging for classical genetic experiments due to trafficking pathway diversity, gene functional redundancy, and lethality in loss-of-function mutants. Many of these difficulties can be bypassed via the use of small molecules to modify or disrupt the function or localization of proteins. Here, we will review examples of the knowledge acquired by the use of such chemical tools in this field, outlining the advantages afforded by chemical biology approaches.
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Affiliation(s)
- Siamsa M Doyle
- Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, 90183 Umeå, Sweden
| | - Thomas Vain
- Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, 90183 Umeå, Sweden
| | - Stéphanie Robert
- Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, 90183 Umeå, Sweden
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18
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Naramoto S, Otegui MS, Kutsuna N, de Rycke R, Dainobu T, Karampelias M, Fujimoto M, Feraru E, Miki D, Fukuda H, Nakano A, Friml J. Insights into the localization and function of the membrane trafficking regulator GNOM ARF-GEF at the Golgi apparatus in Arabidopsis. THE PLANT CELL 2014; 26:3062-76. [PMID: 25012191 PMCID: PMC4145132 DOI: 10.1105/tpc.114.125880] [Citation(s) in RCA: 100] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Revised: 05/28/2014] [Accepted: 06/04/2014] [Indexed: 05/19/2023]
Abstract
GNOM is one of the most characterized membrane trafficking regulators in plants, with crucial roles in development. GNOM encodes an ARF-guanine nucleotide exchange factor (ARF-GEF) that activates small GTPases of the ARF (ADP ribosylation factor) class to mediate vesicle budding at endomembranes. The crucial role of GNOM in recycling of PIN auxin transporters and other proteins to the plasma membrane was identified in studies using the ARF-GEF inhibitor brefeldin A (BFA). GNOM, the most prominent regulator of recycling in plants, has been proposed to act and localize at so far elusive recycling endosomes. Here, we report the GNOM localization in context of its cellular function in Arabidopsis thaliana. State-of-the-art imaging, pharmacological interference, and ultrastructure analysis show that GNOM predominantly localizes to Golgi apparatus. Super-resolution confocal live imaging microscopy identified GNOM and its closest homolog GNOM-like 1 at distinct subdomains on Golgi cisternae. Short-term BFA treatment stabilizes GNOM at the Golgi apparatus, whereas prolonged exposures results in GNOM translocation to trans-Golgi network (TGN)/early endosomes (EEs). Malformed TGN/EE in gnom mutants suggests a role for GNOM in maintaining TGN/EE function. Our results redefine the subcellular action of GNOM and reevaluate the identity and function of recycling endosomes in plants.
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Affiliation(s)
- Satoshi Naramoto
- Department of Plant Systems Biology, VIB, and Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Gent, Belgium Molecular Membrane Biology laboratory, RIKEN Advanced Science Institute, Wako, Saitama 351-0198, Japan Department of Life Science, International Christian University, Mitaka-shi, Tokyo 181-8585, Japan
| | - Marisa S Otegui
- Department of Botany and Genetics, University of Wisconsin, Madison, Wisconsin 53706
| | - Natsumaro Kutsuna
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, University of Tokyo, Kashiwa, Chiba 277-8562, Japan
| | - Riet de Rycke
- Department of Plant Systems Biology, VIB, and Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Gent, Belgium
| | - Tomoko Dainobu
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Michael Karampelias
- Department of Plant Systems Biology, VIB, and Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Gent, Belgium
| | - Masaru Fujimoto
- Laboratory of Plant Molecular Genetics, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Elena Feraru
- Department of Plant Systems Biology, VIB, and Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Gent, Belgium
| | - Daisuke Miki
- Department of Plant Systems Biology, VIB, and Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Gent, Belgium
| | - Hiroo Fukuda
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Akihiko Nakano
- Molecular Membrane Biology laboratory, RIKEN Advanced Science Institute, Wako, Saitama 351-0198, Japan Department of Biological Sciences, Graduate School of Science, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan Live Cell Molecular Imaging Research Team, Extreme Photonics Research Group, RIKEN Center for Advanced Photonics, Wako, Saitama 351-0198, Japan
| | - Jiří Friml
- Department of Plant Systems Biology, VIB, and Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Gent, Belgium Institute of Science and Technology Austria, 3400 Klosterneuburg, Austria
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19
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Kiyama R, Zhu Y. DNA microarray-based gene expression profiling of estrogenic chemicals. Cell Mol Life Sci 2014; 71:2065-82. [PMID: 24399289 PMCID: PMC11113397 DOI: 10.1007/s00018-013-1544-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2013] [Revised: 12/06/2013] [Accepted: 12/16/2013] [Indexed: 12/31/2022]
Abstract
We summarize updated information about DNA microarray-based gene expression profiling by focusing on its application to estrogenic chemicals. First, estrogenic chemicals, including natural/industrial estrogens and phytoestrogens, and the methods for detection and evaluation of estrogenic chemicals were overviewed along with a comprehensive list of estrogenic chemicals of natural or industrial origin. Second, gene expression profiling of chemicals using a focused microarray containing estrogen-responsive genes is summarized. Third, silent estrogens, a new type of estrogenic chemicals characterized by their estrogenic gene expression profiles without growth stimulative or inhibitory effects, have been identified so far exclusively by DNA microarray assay. Lastly, the prospect of a microarray assay is discussed, including issues such as commercialization, future directions of applications and quality control methods.
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Affiliation(s)
- Ryoiti Kiyama
- Signaling Molecules Research Group, Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba, Ibaraki, 305-8566, Japan,
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20
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Abstract
Small GTPases use GDP/GTP alternation to actuate a variety of functional switches that are pivotal for cell dynamics. The GTPase switch is turned on by GEFs, which stimulate dissociation of the tightly bound GDP, and turned off by GAPs, which accelerate the intrinsically sluggish hydrolysis of GTP. For Ras, Rho, and Rab GTPases, this switch incorporates a membrane/cytosol alternation regulated by GDIs and GDI-like proteins. The structures and core mechanisms of representative members of small GTPase regulators from most families have now been elucidated, illuminating their general traits combined with scores of unique features. Recent studies reveal that small GTPase regulators have themselves unexpectedly sophisticated regulatory mechanisms, by which they process cellular signals and build up specific cell responses. These mechanisms include multilayered autoinhibition with stepwise release, feedback loops mediated by the activated GTPase, feed-forward signaling flow between regulators and effectors, and a phosphorylation code for RhoGDIs. The flipside of these highly integrated functions is that they make small GTPase regulators susceptible to biochemical abnormalities that are directly correlated with diseases, notably a striking number of missense mutations in congenital diseases, and susceptible to bacterial mimics of GEFs, GAPs, and GDIs that take command of small GTPases in infections. This review presents an overview of the current knowledge of these many facets of small GTPase regulation.
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Affiliation(s)
- Jacqueline Cherfils
- Laboratoire d’Enzymologie et Biochimie Structurales, Centre National de la Recherche Scientifique, Centre deRecherche de Gif, Gif-sur-Yvette, France
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21
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Dong S, Furutani Y, Kimura S, Zhu Y, Kawabata K, Furutani M, Nishikawa T, Tanaka T, Masaki T, Matsuoka R, Kiyama R. Brefeldin A is an estrogenic, Erk1/2-activating component in the extract of Agaricus blazei mycelia. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2013; 61:128-136. [PMID: 23215459 DOI: 10.1021/jf304546a] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We purified an Erk1/2-activating component in Agaricus blazei and identified it as brefeldin A (BFA). The extract of A. blazei mycelia (ABE) previously showed an estrogenic gene-expression profile and positive effects in patients with cardiovascular symptoms. Here, we demonstrate that BFA has estrogenic activity in reporter gene assays and stimulates an estrogen-receptor pathway revealed by activation of Erk1/2, although BFA had no growth-stimulating activity in breast cancer MCF-7 cells. The presence of estrogenic activity without any explicit growth-stimulating effect is unique to BFA, and such components are termed here "silent estrogens". To test this hypothesis, we examined the target-gene transcription and signaling pathways induced by BFA. Furthermore, BFA was found in the mycelium but not fruiting body of A. blazei, suggesting the potential use of ABE for therapeutics and its supplementary use in traditional medicines and functional foods.
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Affiliation(s)
- Sijun Dong
- Biomedical Research Institute, Research and Innovation Promotion Headquarters, National Institute of Advanced Science and Technology (AIST), Tsukuba, Ibaraki, Japan
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22
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ADP-ribosylation factor machinery mediates endocytosis in plant cells. Proc Natl Acad Sci U S A 2010; 107:21890-5. [PMID: 21118984 DOI: 10.1073/pnas.1016260107] [Citation(s) in RCA: 101] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Endocytosis is crucial for various cellular functions and development of multicellular organisms. In mammals and yeast, ADP-ribosylation factor (ARF) GTPases, key components of vesicle formation, and their regulators ARF-guanine nucleotide exchange factors (GEFs) and ARF-GTPase-activating protein (GAPs) mediate endocytosis. A similar role has not been established in plants, mainly because of the lack of the canonical ARF and ARF-GEF components that are involved in endocytosis in other eukaryotes. In this study, we revealed a regulatory mechanism of endocytosis in plants based on ARF GTPase activity. We identified that ARF-GEF GNOM and ARF-GAP vascular network defective 3 (VAN3), both of which are involved in polar auxin transport-dependent morphogenesis, localize at the plasma membranes as well as in intracellular structures. Variable angle epifluorescence microscopy revealed that GNOM and VAN3 localize to partially overlapping discrete foci at the plasma membranes that are regularly associated with the endocytic vesicle coat clathrin. Genetic studies revealed that GNOM and VAN3 activities are required for endocytosis and internalization of plasma membrane proteins, including PIN-FORMED auxin transporters. These findings identified ARF GTPase-based regulatory mechanisms for endocytosis in plants. GNOM and VAN3 previously were proposed to function solely at the recycling endosomes and trans-Golgi networks, respectively. Therefore our findings uncovered an additional cellular function of these prominent developmental regulators.
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23
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Ben-Tekaya H, Kahn RA, Hauri HP. ADP ribosylation factors 1 and 4 and group VIA phospholipase A₂ regulate morphology and intraorganellar traffic in the endoplasmic reticulum-Golgi intermediate compartment. Mol Biol Cell 2010; 21:4130-40. [PMID: 20881058 PMCID: PMC2993742 DOI: 10.1091/mbc.e10-01-0022] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
In search of morphological determinants for the endoplasmic reticulum-Golgi intermediate compartment (ERGIC), we found that a concerted action of Arf1, Arf4, and PLA2G6-A controls the architecture of the ERGIC by regulating tubular carriers. This is predicted to impact the rate of transport and destination of cargos in the ERGIC. Organelle morphology of the endomembrane system is critical for optimal organelle function. ADP ribosylation factors (Arfs), a family of small GTPases, are required for maintaining the structure of the Golgi and endosomes. What determines the discontinuous nature of the endoplasmic reticulum (ER)–Golgi intermediate compartment (ERGIC) as tubulovesicular clusters is unknown. In search of morphological determinants for the ERGIC, we found that a double knockdown of Arf1+Arf4 induced dynamic ERGIC tubules that connect ERGIC clusters, indicating that the tubules mediated lateral intraERGIC traffic. Tubule formation was inhibited by an antagonist of group VI calcium-independent phospholipase A2 (PLA2G6) and by silencing the A isoform of PLA2G6 (PLA2G6-A). Arf1+Arf4 depletion altered the expression of PLA2G6-A splice variants and relocalized PLA2G6-A from the cytosol to ERGIC clusters and tubules, suggesting that the enzyme became locally active. We show that changes in Arf1 can modulate the activity of PLA2G6-A. We propose that a concerted action of Arf1, Arf4, and PLA2G6-A controls the architecture of the ERGIC in a way that is predicted to impact the rate and possibly the destination of cargos. Our findings have identified key components in the molecular mechanism underlying the regulation of tubules in the ERGIC and uncover tubular carriers as tightly controlled machinery.
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24
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Peterson-Kaufman KJ, Carlson CD, Rodríguez-Martínez JA, Ansari AZ. Nucleating the assembly of macromolecular complexes. Chembiochem 2010; 11:1955-62. [PMID: 20812316 PMCID: PMC4176617 DOI: 10.1002/cbic.201000255] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2010] [Indexed: 12/23/2022]
Abstract
Nature constructs intricate complexes containing numerous binding partners in order to direct a variety of cellular processes. Researchers have taken a cue from these events to develop synthetic molecules that can nucleate natural and unnatural interactions for a diverse set of applications. These molecules can be designed to drive protein dimerization or to modulate the interactions between proteins, lipids, DNA, or RNA and thereby alter cellular pathways. A variety of components within the cellular machinery can be recruited with or replaced by synthetic compounds. Directing the formation of multicomponent complexes with new synthetic molecules can allow unprecedented control over the cellular machinery.
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Affiliation(s)
| | - Clayton D. Carlson
- Department of Biochemistry and the Genome Center, University of Wisconsin, 433 Babcock Drive. Madison, WI 53706
| | - José A. Rodríguez-Martínez
- Department of Biochemistry and the Genome Center, University of Wisconsin, 433 Babcock Drive. Madison, WI 53706
| | - Aseem Z. Ansari
- Department of Biochemistry and the Genome Center, University of Wisconsin, 433 Babcock Drive. Madison, WI 53706
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25
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Cho HJ, Baek KE, Yoo J. RhoGDI2 as a therapeutic target in cancer. Expert Opin Ther Targets 2010; 14:67-75. [PMID: 20001211 DOI: 10.1517/14728220903449251] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
IMPORTANCE OF THE FIELD Rho GDP dissociation inhibitor 2 (RhoGDI2) has been identified as a regulator of Rho GTPases that play important roles in the development of numerous aspects of the malignant phenotype, including cell cycle progression, resistance to apoptotic stimuli, neovascularization, tumor cell motility, invasiveness, and metastasis. Although RhoGDI2 has been known to be expressed only in hematopoietic tissues, recent studies suggest that this protein is also aberrantly expressed in several human cancers and contributes to aggressive phenotypes, such as invasion and metastasis. Hence, RhoGDI2 appears to be a target of interest for therapeutic manipulation. AREAS COVERED IN THIS REVIEW Here, we summarize the role of RhoGDI2 in human cancers, specifically metastasis-related processes, and discuss its potential as a therapeutic target. WHAT THE READER WILL GAIN RhoGDI2 modulates the invasiveness and metastatic ability of cancer cells through regulation of Rac1 activity. TAKE HOME MESSAGE RhoGDI2 may be a useful marker for tumor progression in human cancers, and interruption of the RhoGDI2-mediated cancer cell invasion and metastasis by an interfacial inhibitor may be a powerful therapeutic approach to cancer.
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Affiliation(s)
- Hee Jun Cho
- Gyeongsang National University, College of Natural Sciences, Research Institute of Life Science, Department of Microbiology, Jinju 660-701, Korea
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26
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Guetzoyan LJ, Spooner RA, Boal F, Stephens DJ, Lord JM, Roberts LM, Clarkson GJ. Fine tuning Exo2, a small molecule inhibitor of secretion and retrograde trafficking pathways in mammalian cells. MOLECULAR BIOSYSTEMS 2010; 6:2030-8. [DOI: 10.1039/c0mb00035c] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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27
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Asymmetric deactivation of HIV-1 gp41 following fusion inhibitor binding. PLoS Pathog 2009; 5:e1000674. [PMID: 19956769 PMCID: PMC2776349 DOI: 10.1371/journal.ppat.1000674] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2009] [Accepted: 10/30/2009] [Indexed: 12/12/2022] Open
Abstract
Both equilibrium and nonequilibrium factors influence the efficacy of pharmaceutical agents that target intermediate states of biochemical reactions. We explored the intermediate state inhibition of gp41, part of the HIV-1 envelope glycoprotein complex (Env) that promotes viral entry through membrane fusion. This process involves a series of gp41 conformational changes coordinated by Env interactions with cellular CD4 and a chemokine receptor. In a kinetic window between CD4 binding and membrane fusion, the N- and C-terminal regions of the gp41 ectodomain become transiently susceptible to inhibitors that disrupt Env structural transitions. In this study, we sought to identify kinetic parameters that influence the antiviral potency of two such gp41 inhibitors, C37 and 5-Helix. Employing a series of C37 and 5-Helix variants, we investigated the physical properties of gp41 inhibition, including the ability of inhibitor-bound gp41 to recover its fusion activity once inhibitor was removed from solution. Our results indicated that antiviral activity critically depended upon irreversible deactivation of inhibitor-bound gp41. For C37, which targets the N-terminal region of the gp41 ectodomain, deactivation was a slow process that depended on chemokine receptor binding to Env. For 5-Helix, which targets the C-terminal region of the gp41 ectodomain, deactivation occurred rapidly following inhibitor binding and was independent of chemokine receptor levels. Due to this kinetic disparity, C37 inhibition was largely reversible, while 5-Helix inhibition was functionally irreversible. The fundamental difference in deactivation mechanism points to an unappreciated asymmetry in gp41 following inhibitor binding and impacts the development of improved fusion inhibitors and HIV-1 vaccines. The results also demonstrate how the activities of intermediate state inhibitors critically depend upon the final disposition of inhibitor-bound states.
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Nakano RT, Matsushima R, Ueda H, Tamura K, Shimada T, Li L, Hayashi Y, Kondo M, Nishimura M, Hara-Nishimura I. GNOM-LIKE1/ERMO1 and SEC24a/ERMO2 are required for maintenance of endoplasmic reticulum morphology in Arabidopsis thaliana. THE PLANT CELL 2009; 21:3672-85. [PMID: 19933201 PMCID: PMC2798326 DOI: 10.1105/tpc.109.068270] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2009] [Revised: 10/09/2009] [Accepted: 10/17/2009] [Indexed: 05/19/2023]
Abstract
The endoplasmic reticulum (ER) is composed of tubules, sheets, and three-way junctions, resulting in a highly conserved polygonal network in all eukaryotes. The molecular mechanisms responsible for the organization of these structures are obscure. To identify novel factors responsible for ER morphology, we employed a forward genetic approach using a transgenic Arabidopsis thaliana plant (GFP-h) with fluorescently labeled ER. We isolated two mutants with defects in ER morphology and designated them endoplasmic reticulum morphology1 (ermo1) and ermo2. The cells of both mutants developed a number of ER-derived spherical bodies, approximately 1 microm in diameter, in addition to the typical polygonal network of ER. The spherical bodies were distributed throughout the ermo1 cells, while they formed a large aggregate in ermo2 cells. We identified the responsible gene for ermo1 to be GNOM-LIKE1 (GNL1) and the gene for ermo2 to be SEC24a. Homologs of both GNL1 and SEC24a are involved in membrane trafficking between the ER and Golgi in yeast and animal cells. Our findings, however, suggest that GNL1/ERMO1 and SEC24a/ERMO2 have a novel function in ER morphology in higher plants.
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Affiliation(s)
- Ryohei Thomas Nakano
- Department of Botany, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Ryo Matsushima
- Department of Botany, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Haruko Ueda
- Department of Botany, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Kentaro Tamura
- Department of Botany, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Tomoo Shimada
- Department of Botany, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Lixin Li
- Department of Botany, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Yasuko Hayashi
- Department of Environmental Science, Faculty of Science, Niigata University, Niigata 950-2181, Japan
| | - Maki Kondo
- Department of Cell Biology, National Institute for Basic Biology, Okazaki 444-8585, Japan
| | - Mikio Nishimura
- Department of Cell Biology, National Institute for Basic Biology, Okazaki 444-8585, Japan
| | - Ikuko Hara-Nishimura
- Department of Botany, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
- Address correspondence to
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Ferland RJ, Batiz LF, Neal J, Lian G, Bundock E, Lu J, Hsiao YC, Diamond R, Mei D, Banham AH, Brown PJ, Vanderburg CR, Joseph J, Hecht JL, Folkerth R, Guerrini R, Walsh CA, Rodriguez EM, Sheen VL. Disruption of neural progenitors along the ventricular and subventricular zones in periventricular heterotopia. Hum Mol Genet 2008; 18:497-516. [PMID: 18996916 DOI: 10.1093/hmg/ddn377] [Citation(s) in RCA: 138] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Periventricular heterotopia (PH) is a disorder characterized by neuronal nodules, ectopically positioned along the lateral ventricles of the cerebral cortex. Mutations in either of two human genes, Filamin A (FLNA) or ADP-ribosylation factor guanine exchange factor 2 (ARFGEF2), cause PH (Fox et al. in 'Mutations in filamin 1 prevent migration of cerebral cortical neurons in human periventricular heterotopia'. Neuron, 21, 1315-1325, 1998; Sheen et al. in 'Mutations in ARFGEF2 implicate vesicle trafficking in neural progenitor proliferation and migration in the human cerebral cortex'. Nat. Genet., 36, 69-76, 2004). Recent studies have shown that mutations in mitogen-activated protein kinase kinase kinase-4 (Mekk4), an indirect interactor with FlnA, also lead to periventricular nodule formation in mice (Sarkisian et al. in 'MEKK4 signaling regulates filamin expression and neuronal migration'. Neuron, 52, 789-801, 2006). Here we show that neurons in post-mortem human PH brains migrated appropriately into the cortex, that periventricular nodules were primarily composed of later-born neurons, and that the neuroependyma was disrupted in all PH cases. As studied in the mouse, loss of FlnA or Big2 function in neural precursors impaired neuronal migration from the germinal zone, disrupted cell adhesion and compromised neuroepithelial integrity. Finally, the hydrocephalus with hop gait (hyh) mouse, which harbors a mutation in Napa [encoding N-ethylmaleimide-sensitive factor attachment protein alpha (alpha-SNAP)], also develops a progressive denudation of the neuroepithelium, leading to periventricular nodule formation. Previous studies have shown that Arfgef2 and Napa direct vesicle trafficking and fusion, whereas FlnA associates dynamically with the Golgi membranes during budding and trafficking of transport vesicles. Our current findings suggest that PH formation arises from a final common pathway involving disruption of vesicle trafficking, leading to impaired cell adhesion and loss of neuroependymal integrity.
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Affiliation(s)
- Russell J Ferland
- Department of Biology, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180, USA
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The secretion inhibitor Exo2 perturbs trafficking of Shiga toxin between endosomes and the trans-Golgi network. Biochem J 2008; 414:471-84. [PMID: 18522538 PMCID: PMC2552392 DOI: 10.1042/bj20080149] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The small-molecule inhibitor Exo2 {4-hydroxy-3-methoxy-(5,6,7,8-tetrahydrol[1]benzothieno[2,3-d]pyrimidin-4-yl)hydraz-one benzaldehyde} has been reported to disrupt the Golgi apparatus completely and to stimulate Golgi–ER (endoplasmic reticulum) fusion in mammalian cells, akin to the well-characterized fungal toxin BFA (brefeldin A). It has also been reported that Exo2 does not affect the integrity of the TGN (trans-Golgi network), or the direct retrograde trafficking of the glycolipid-binding cholera toxin from the TGN to the ER lumen. We have examined the effects of BFA and Exo2, and found that both compounds are indistinguishable in their inhibition of anterograde transport and that both reagents significantly disrupt the morphology of the TGN in HeLa and in BS-C-1 cells. However, Exo2, unlike BFA, does not induce tubulation and merging of the TGN and endosomal compartments. Furthermore, and in contrast with its effects on cholera toxin, Exo2 significantly perturbs the delivery of Shiga toxin to the ER. Together, these results suggest that the likely target(s) of Exo2 operate at the level of the TGN, the Golgi and a subset of early endosomes, and thus Exo2 provides a more selective tool than BFA for examining membrane trafficking in mammalian cells.
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Flisiak S, Zeeh JC, Guibert B, Cherfils J, Zeghouf M. An Arf1 GTPase mutant with different responses to GEF inhibitors. Biochem Biophys Res Commun 2008; 377:156-60. [PMID: 18834864 DOI: 10.1016/j.bbrc.2008.09.107] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2008] [Accepted: 09/21/2008] [Indexed: 10/21/2022]
Abstract
Guanine nucleotide exchange factors (GEFs) stimulate the activation of small GTP-binding proteins (GTPases). Establishing their specificity is a challenging issue, in which chemical genetics are rapidly gaining interest. We report a mutation in the Arf1 GTPase, K38A, which differentially alters its sensitivity to GEF inhibitors. The mutation renders Arf1 insensitive to LM11, a GEF inhibitor that we previously discovered by structure-based screening. In contrast, full inhibition by the natural compound Brefeldin A (BFA) is retained. We show that the mutation is otherwise silent towards the biochemical and cellular properties of Arf1, notably its binding to effectors as measured by a novel GEF-protection assay. This is thus the first GTPase mutant with different responses to two classes of inhibitors, and a novel tool to analyze Arf and ArfGEF specificity and functions in vitro and in cells.
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Affiliation(s)
- Sebastian Flisiak
- Laboratoire d'Enzymologie et Biochimie Structurales, CNRS, Gif-sur-Yvette, France
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Rufanova VA, Lianos E, Alexanian A, Sorokina E, Sharma M, McGinty A, Sorokin A. C3G overexpression in glomerular epithelial cells during anti-GBM-induced glomerulonephritis. Kidney Int 2008; 75:31-40. [PMID: 18784646 DOI: 10.1038/ki.2008.448] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The guanine nucleotide exchange factor C3G, along with the CrkII adaptor protein, mediates GTP activation of the small GTPase proteins Rap1 and R-Ras, facilitating their activation of downstream signaling pathways, which had been found to be important in the pathogenesis of glomerulonephritis. We found that expression of C3G protein was upregulated in glomerular epithelial cells in an experimental model of accelerated anti-GBM antibody-induced glomerulonephritis expression. To determine the consequence of its increased expression, we transfected C3G (using adenoviral constructs) into cultured glomerular epithelial cells and measured the activated forms (i.e., GTP-bound) forms of Rap1 and R-Ras. Activation of Rap1 was not affected by C3G; however, the basal level of GTP-bound R-Ras was decreased. Further, C3G over-expression enhanced the activation of R-Ras in response to endothelin. Overexpression of C3G also led to a significant reduction in glomerular epithelial cell spreading and decreased the cells' E-cadherin expression and augmented their migration. We found that C3G was overexpressed in accelerated anti-GBM antibody-induced glomerulonephritis and suggest that this modulates glomerular epithelial cell morphology and behavior.
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Affiliation(s)
- Victoriya A Rufanova
- Division of Nephrology and Kidney Disease Center, Department of Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
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Konstantinopoulos PA, Karamouzis MV, Papavassiliou AG. Post-translational modifications and regulation of the RAS superfamily of GTPases as anticancer targets. Nat Rev Drug Discov 2007; 6:541-55. [PMID: 17585331 DOI: 10.1038/nrd2221] [Citation(s) in RCA: 355] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The involvement of the RAS superfamily of monomeric GTPases in carcinogenesis is increasingly being appreciated. A complex array of post-translational modifications and a highly sophisticated protein network regulate the spatio-temporal activation of these GTPases. Previous attempts to pharmacologically target this family have focused on the development of farnesyltransferase inhibitors, but the performance of such agents in cancer clinical trials has not been as good as hoped. Here, we review emerging druggable targets and novel therapeutic approaches targeting prenylation and post-prenylation modifications and the functional regulation of GDP/GTP exchange as exciting alternatives for anticancer therapy.
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Viaud J, Zeghouf M, Barelli H, Zeeh JC, Padilla A, Guibert B, Chardin P, Royer CA, Cherfils J, Chavanieu A. Structure-based discovery of an inhibitor of Arf activation by Sec7 domains through targeting of protein-protein complexes. Proc Natl Acad Sci U S A 2007; 104:10370-5. [PMID: 17563369 PMCID: PMC1965520 DOI: 10.1073/pnas.0700773104] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2007] [Indexed: 12/24/2022] Open
Abstract
Small molecules that produce nonfunctional protein-protein complexes are an alternative to competitive inhibitors for the inhibition of protein functions. Here we target the activation of the small GTP-binding protein Arf1, a major regulator of membrane traffic, by the Sec7 catalytic domain of its guanine nucleotide exchange factor ARNO. The crystal structure of the Arf1-GDP/ARNO complex, which initiates the exchange reaction, was used to discover an inhibitor, LM11, using in silico screening of a flexible pocket near the Arf1/ARNO interface. Using fluorescence kinetics and anisotropy, NMR spectroscopy and mutagenesis, we show that LM11 acts following a noncompetitive mechanism in which the inhibitor targets both Arf1-GDP and the Arf1-GDP/ARNO complex and produces a nonfunctional Arf-GDP/ARNO complex whose affinity is similar to that of the native complex. In addition, LM11 recognizes features of both Arf and ARNO near the Arf/Sec7 interface, a characteristic reminiscent of the paradigm interfacial inhibitor Brefeldin A. We then show that LM11 is a cell-active inhibitor that impairs Arf-dependent trafficking structures at the Golgi. Furthermore, LM11 inhibits ARNO-dependent migration of Madin-Darby canine kidney (MDCK) cells, demonstrating that ARNO is a target of LM11 in cells. Remarkably, LM11 inhibits the activation of Arf1 but not Arf6 in vitro, pointing to a possible synergy between Arf1 and Arf6 activation by ARNO in cell migration. Our design method shows that flexible regions in protein-protein complexes provide drugable sites with the potential to develop novel tools for investigating and inhibiting signaling pathways.
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Affiliation(s)
- Julien Viaud
- *Institut National de la Santé et de la Recherche Médicale, U554 and
- Université Montpellier 1 et 2, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 5048, Centre de Biochimie Structurale, 34090 Montpellier, France
| | - Mahel Zeghouf
- Laboratoire d'Enzymologie et Biochimie Structurales, Centre National de la Recherche Scientifique, Avenue de la Terrasse, 91198 Gif sur Yvette Cedex, France; and
| | - Hélène Barelli
- Institut de Pharmacologie Moléculaire et Cellulaire, Centre National de la Recherche Scientifique–Unité Mixte de Recherche 6097, 660 Route des Lucioles, 06560 Valbonne, France
| | - Jean-Christophe Zeeh
- Laboratoire d'Enzymologie et Biochimie Structurales, Centre National de la Recherche Scientifique, Avenue de la Terrasse, 91198 Gif sur Yvette Cedex, France; and
| | - André Padilla
- *Institut National de la Santé et de la Recherche Médicale, U554 and
- Université Montpellier 1 et 2, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 5048, Centre de Biochimie Structurale, 34090 Montpellier, France
| | - Bernard Guibert
- Laboratoire d'Enzymologie et Biochimie Structurales, Centre National de la Recherche Scientifique, Avenue de la Terrasse, 91198 Gif sur Yvette Cedex, France; and
| | - Pierre Chardin
- Institut de Pharmacologie Moléculaire et Cellulaire, Centre National de la Recherche Scientifique–Unité Mixte de Recherche 6097, 660 Route des Lucioles, 06560 Valbonne, France
| | - Catherine A. Royer
- *Institut National de la Santé et de la Recherche Médicale, U554 and
- Université Montpellier 1 et 2, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 5048, Centre de Biochimie Structurale, 34090 Montpellier, France
| | - Jacqueline Cherfils
- Laboratoire d'Enzymologie et Biochimie Structurales, Centre National de la Recherche Scientifique, Avenue de la Terrasse, 91198 Gif sur Yvette Cedex, France; and
| | - Alain Chavanieu
- *Institut National de la Santé et de la Recherche Médicale, U554 and
- Université Montpellier 1 et 2, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 5048, Centre de Biochimie Structurale, 34090 Montpellier, France
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35
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Newell-Litwa K, Seong E, Burmeister M, Faundez V. Neuronal and non-neuronal functions of the AP-3 sorting machinery. J Cell Sci 2007; 120:531-41. [PMID: 17287392 DOI: 10.1242/jcs.03365] [Citation(s) in RCA: 111] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Vesicles selectively exchange lipids, membrane proteins and luminal contents between organelles along the exocytic and endocytic routes. The repertoire of membrane proteins present in these vesicles is crucial for their targeting and function. Vesicle composition is determined at the time of their biogenesis by cytosolic coats. The heterotetrameric protein adaptor protein complex 3 (AP-3), a coat component, participates in the generation of a diverse group of secretory organelles and lysosome-related organelles. Recent work has shed light on the mechanisms that regulate AP-3 and the trafficking pathways controlled by this adaptor. Phenotypic analysis of organisms carrying genetic deficiencies in the AP-3 pathway highlight its role regulating the targeting of lysosomal, melanosomal and synaptic vesicle-specific membrane proteins. Synaptic vesicles from AP-3-deficient mice possess altered levels of neurotransmitter and ion transporters, molecules that ultimately define the type and amount of neurotransmitter stored in these vesicles. These findings reveal a complex picture of how AP-3 functions in multiple tissues, including neuronal tissue, and expose potential links between endocytic sorting mechanisms and the pathogenesis of psychiatric disorders such as schizophrenia.
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36
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Zeeh JC, Zeghouf M, Grauffel C, Guibert B, Martin E, Dejaegere A, Cherfils J. Dual specificity of the interfacial inhibitor brefeldin a for arf proteins and sec7 domains. J Biol Chem 2006; 281:11805-14. [PMID: 16484231 DOI: 10.1074/jbc.m600149200] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Guanine nucleotide exchange factors (GEFs), which activate small GTP-binding proteins (SMG) by stimulating their GDP/GTP exchange, are emerging as candidate targets for the inhibition of cellular pathways involved in diseases. However, their specific inhibition by competitive inhibitors is challenging, because GEF and SMG families comprise highly similar members. Nature shows us an alternative strategy called interfacial inhibition, exemplified by Brefeldin A (BFA). BFA inhibits the activation of Arf1 by its GEFs in vivo by stabilizing an abortive complex between Arf-GDP and the catalytic Sec7 domain of some of its GEFs. Here we characterize the specificity of BFA toward wild-type (ARNO and BIG1) and mutant Sec7 domains and toward class I, II, and III Arfs. We find that BFA sensitivity of the exchange reaction depends on the nature of both the Sec7 domain and the Arf protein. A single Phe/Tyr substitution is sufficient to achieve BFA sensitivity of the Sec7 domain, which is supported by our characterization of brefeldin C (BFC), a BFA analog that cannot interact with the Tyr residue, and by free energy computations. We further show that Arf1 and Arf5, but not Arf6, are BFA-sensitive, despite their having every BFA-interacting residue in common. Analysis of Arf6 mutants points to the dynamics of the interswitch, which is involved in membrane-to-nucleotide signal propagation, as contributing to, although not sufficient for, BFA sensitivity. Altogether, our results reveal the Tyr/Phe substitution as a novel tool for monitoring BFA sensitivity of cellular ArfGEFs and document the exquisite and dual specificity that can be achieved by an interfacial inhibitor.
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Affiliation(s)
- Jean-Christophe Zeeh
- Laboratoire d'Enzymologie et Biochimie Structurales, CNRS, Avenue de la Terrasse, 91198 Gif sur Yvette, France
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