DOCSLIB.ORG

Phospholipase D by Rala R-Mediated Phagocytosis

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Phospholipase D by Rala R-Mediated Phagocytosis Ral Isoforms Are Implicated in Fcγ R-Mediated Phagocytosis: Activation of Phospholipase D by RalA This information is current as Matthias Corrotte, An Phu Tran Nyguyen, Marie Line of September 28, 2021. Harlay, Nicolas Vitale, Marie-France Bader and Nancy J. Grant J Immunol 2010; 185:2942-2950; Prepublished online 2 August 2010; doi: 10.4049/jimmunol.0903138 Downloaded from http://www.jimmunol.org/content/185/5/2942 Supplementary http://www.jimmunol.org/content/suppl/2010/07/30/jimmunol.090313 Material 8.DC1 http://www.jimmunol.org/ References This article cites 45 articles, 26 of which you can access for free at: http://www.jimmunol.org/content/185/5/2942.full#ref-list-1 Why The JI? Submit online. • Rapid Reviews! 30 days* from submission to initial decision by guest on September 28, 2021 • No Triage! Every submission reviewed by practicing scientists • Fast Publication! 4 weeks from acceptance to publication *average Subscription Information about subscribing to The Journal of Immunology is online at: http://jimmunol.org/subscription Permissions Submit copyright permission requests at: http://www.aai.org/About/Publications/JI/copyright.html Email Alerts Receive free email-alerts when new articles cite this article. Sign up at: http://jimmunol.org/alerts The Journal of Immunology is published twice each month by The American Association of Immunologists, Inc., 1451 Rockville Pike, Suite 650, Rockville, MD 20852 Copyright © 2010 by The American Association of Immunologists, Inc. All rights reserved. Print ISSN: 0022-1767 Online ISSN: 1550-6606. The Journal of Immunology Ral Isoforms Are Implicated in FcgR-Mediated Phagocytosis: Activation of Phospholipase D by RalA Matthias Corrotte, An Phu Tran Nyguyen, Marie Line Harlay, Nicolas Vitale, Marie-France Bader, and Nancy J. Grant Phagocytosis is an essential element of the immune response permitting the elimination of pathogens, cellular debris, apoptotic cells, and tumor cells. Recently, both phospholipase D (PLD) isoforms, PLD1 and PLD2, were shown to be necessary for efficient FcgR-mediated phagocytosis. In this study, we investigated the role of a potential PLD regulator, the Ral GTPases RalA and RalB, in murine RAW 264.7 macrophages. Both Ral isoforms are expressed in macrophages and are transiently activated following FcgR stimulation. When Ral expression levels were varied using Ral mutants or interference RNA, phago- cytosis assays revealed that Ral isoforms have antagonistic effects; RalA is a positive modulator, whereas RalB plays a negative role. We then focused on RalA and its possible relationship with PLD. The increase in PLD activity that occurs when phagocytosis Downloaded from is stimulated was inhibited in cells with reduced RalA protein, but it was unaffected by reduced levels of RalB. Furthermore, in macrophages transfected with dsRed-RalA and GFP-PLD1 or GFP-PLD2, RalA colocalized with PLD1 and PLD2 at the phago- cytic cup during phagosome formation. Additional results obtained from immunoprecipitation of PLD from macrophages trans- fected with myc-RalA and hemagglutinin-tagged PLD1 or PLD2 indicated an enhanced interaction of RalA with both PLD isoforms during phagocytic stimulation. The increase in RalA and PLD1 interaction was transient and correlated with the time course of RalA activation. These findings reveal a novel pathway involving RalA and PLD in the regulation of FcgR-mediated http://www.jimmunol.org/ phagocytosis. The Journal of Immunology, 2010, 185: 2942–2950. hagocytosis is a complex, evolutionarily conserved process phagosome matures into a phagolysosome through interactions with that permits the internalization and degradation of large the endosomal–lysosomal pathway, leading to acidification of the P particles (.0.5 mm) in diverse cellular functions, ranging vacuole, degradation of the ingested material, and its eventual recy- from nutrition in unicellular organisms and remodeling of tissues cling for Ag presentation (5). during development to the maintenance of homeostasis and elimi- Membrane trafficking is essential for phagocytosis during the nation of pathogens in the immune response of higher organisms. formation and maturation of the phagosome. A number of intra- by guest on September 28, 2021 The phagocytic signal is triggered by a variety of receptors, in- cellular compartments, including early and late endosomes, lyso- cluding the extensively studied FcgR, which recognizes the con- somes (6), and the endoplasmic reticulum (7), have been proposed stant fragment of Ig opsonized on particles (1). Following activation as membrane sources for focal exocytosis at phagocytic sites. and clustering of the FcgR, signal transduction leads to rearrange- SNARE complexes (8, 9) and different phospholipids (10, 11) are ments of the actin cytoskeleton that drive the extension of pseu- involved in these membrane-trafficking events. Phospholipase D dopods around the particle to form the phagosome, the vacuole in (PLD) activity, which generates phosphatidic acid (PA) from phos- which the particle is engulfed. To maintain homeostasis of the cell phatidylcholine, was reported to increase during activation of sev- surface, this step also requires the insertion of endomembranes by eral phagocytosis receptors, including FcgR (12). Recently, we focal exocytosis (2), which depends on actomyosin contractile ac- demonstrated that PA is produced at phagocytic sites and that the tivity (3) and membrane-fusion events (4). After internalization, the PLD isoforms PLD1 and PLD2 are necessary for efficient phago- cytosis (13). PLD2 is present at the plasma membrane, whereas the De´partement Neurotransmission et Se´cre´tion Neuroendocrine, Institut des Neuro- isoform PLD1 is associated with the late endosome/lysosome com- sciences Cellulaires et Inte´gratives, Centre National de la Recherche Scientifique, Unite´ Propre de Recherche 3212, Strasbourg, France partment that is recruited to phagocytic sites, suggesting a role for PLD in focal exocytosis during phagosome formation (13). How the Received for publication September 23, 2009. Accepted for publication June 30, 2010. PLD isoforms are regulated and their cellular functions during This work was supported by grants from the Agence National de la Recherches phagocytosis remain to be elucidated. (ANR-09-BLAN-0264-01) and the Association pour la Recherche´ sur le Cancer The monomeric Ral GTPases are potential regulators of PLD. (ARC4051). RalA and RalB form a subgroup of the superfamily of Ras proteins Address correspondence and reprint requests to Dr. Nancy J. Grant, De´partement and share ∼85% homology in their amino acid sequences. The Neurotransmission et Se´cre´tion Neuroendocrine, Institut des Neurosciences Cellu- laires et Inte´gratives, Centre National de la Recherche Scientifique, Unite´ Propre de importance of the Ral GTPases in membrane-trafficking events and Recherche 3212, 5 Rue Blaise Pascal, Strasbourg 67084, France. E-mail address: organization of the actin cytoskeleton is well established in a num- [email protected] ber of cellular functions, such as cell migration, neurite branching, The online version of this article contains supplemental material. receptor endocytosis, and regulated exocytosis (14). In this study, Abbreviations used in this paper: Ag-Ig, aggregated Ig; BSA, BSA-coated; HA, the functional importance of Ral proteins in phagocytosis was in- hemagglutinin; IgG, IgG opsonized; IP, immunoprecipitates; iRNA, interference RNA; Memb, organelles and large membrane fragments; NC, noncoated; NS, nonstimulated vestigated, in particular the relationship between RalA and PLD cells; PA, phosphatidic acid; pEGFP, enhanced GFP; PLD, phospholipase D; RalA-WT, isoforms during phagosome formation. Ral proteins were observed RalA wild type; RalB-WT, RalB wild type; Sol, soluble cytoplasmic fraction. to have opposing roles in mediating the internalization of 3-mm Copyright Ó 2010 by The American Association of Immunologists, Inc. 0022-1767/10/$16.00 IgG-opsonized particles: RalA acts as a positive modulator, www.jimmunol.org/cgi/doi/10.4049/jimmunol.0903138 The Journal of Immunology 2943 whereas RalB plays a negative role. Additional results provide Phagocytosis assay evidence that RalA interacts with the PLD isoforms and regulates For these assays, phagocytosis was synchronized by adding IgG-opsonized PLD activity, suggesting that a pathway involving RalA and PLD particles to cells grown on glass coverslips, centrifuging cells for 2 min at modulates the efficiency of FcgR-dependent phagocytosis in mac- 100 3 g at 18˚C, and then initiating phagocytosis by placing them at 37˚C, rophages. as previously described (13). Briefly, phagocytosis was stopped 5 or 30 min later by washing twice in cold PBS. At these time points, the uptake of nonopsonized particles was negligible. After fixation, external beads were labeled with goat anti-human IgG coupled to Alexa Fluor 555. Cells trans- Materials and Methods fected with Ral plasmids were identified by permeabilizing cells in Cell culture Triton X-100 and labeling with anti-myc Ab. Unlabeled internalized beads were visualized with phase-contrast optics. The number of internalized Culture conditions for the murine macrophage RAW 267.4 cell line in RPMI beads per cell was determined for randomly chosen fields ($80 cells for 1640-glutamax medium supplemented with 10% FBS were as described each condition) using superimposed fluorescent and phase-contrast images previously (13). (Adobe Photoshop 9). After determining the mean number of beads in- ternalized per cell, the phagocytic
Load more

Recommended publications
  • Rala Requirement for V-Src- and V-Ras-Induced Tumorigenicity and Overproduction of Urokinase-Type Plasminogen Activator: Involvement of Metalloproteases
    Oncogene (1999) 18, 4718 ± 4725 ã 1999 Stockton Press All rights reserved 0950 ± 9232/99 $15.00 http://www.stockton-press.co.uk/onc RalA requirement for v-Src- and v-Ras-induced tumorigenicity and overproduction of urokinase-type plasminogen activator: involvement of metalloproteases Julio A Aguirre-Ghiso*,1,4, Paul Frankel2, Eduardo F Farias1, Zhimin Lu2, Hong Jiang2,5, Amanda Olsen2, Larry A Feig3, Elisa Bal de Kier Joe1 and David A Foster2 1Cell Biology Department, Research Area, Institute of Oncology, `Angel H Roo', University of Buenos Aires, Buenos Aires 1417, Argentina; 2Department of Biological Sciences, Hunter College of The City University of New York, New York, NY 10021, USA; 3Department of Biochemistry, Tufts University School of Medicine, Boston, Massachusetts, MA 02111, USA Overproduction of urokinase-type plasminogen activator Introduction (uPA) and metalloproteases (MMPs) is strongly corre- lated with tumorigenicity and with invasive and meta- Metastasis is the last and most lethal stage of tumor static phenotypes of human and experimental tumors. progression. This process follows several steps including We demonstrated previously that overproduction of uPA the exit of tumor cells from the primary tumor, in tumor cells is mediated by a phospholipase D (PLD)- intravasation after degradation of the interstitial and and protein kinase C-dependent mechanism. The onco- the blood vessels extracellular matrix, dissemination genic stimulus of v-Src and v-Ras results in the through the lymphatic or arterial system, and ®nally activation of PLD, which is dependent upon the extravasation, settlement, and growth in a distant organ monomeric GTPase RalA. We have therefore investi- (Hart et al., 1989).
    [Show full text]
  • Putting Rac1 on the Path to Glucose Uptake Assaf Rudich1 and Amira Klip2
    COMMENTARY Putting Rac1 on the Path to Glucose Uptake Assaf Rudich1 and Amira Klip2 Rac1 is an obligatory element in the stimulation of glucose uptake by insulin in skeletal muscle. Insulin caused Rac1 n spite of numerous and key advances in our un- activation (GTP loading) in mouse muscle ex vivo, and derstanding of insulin signaling, the molecular basis muscles of mice conditionally lacking Rac1 in skeletal mus- for impaired insulin-stimulated glucose uptake un- cle, or treated with Rac inhibitors, showed reduced insulin- Iderlying insulin resistance remains unclear. Because simulated glucose uptake. Under these circumstances, skeletal muscle accounts for the majority of glucose utili- insulin-stimulated Akt was not affected. These data comple- zation in the postprandial insulin-regulated state, defects in ment a previous study with another muscle-specific Rac1- insulin action in muscle can determine whole-body glu- knockout mouse model, in which insulin-triggered GLUT4 cose utilization. In muscle and fat cells, overall similarities translocation was reduced (9). exist in the signals emanating from the insulin receptor Which Rac1 effectors are promoting glucose uptake? that mobilize glucose transporter GLUT4 to the membrane. The studies in cell culture have already revealed the acti- Importantly, defects in the signaling network connecting vation of three Rac-effector pathways: The aforementioned the activated insulin receptor to GLUT4 vesicles are of Arp2/3 (mediated by nucleating factors of the Wave family particular consequence to insulin resistance in muscle, where, and leading to actin remodeling) (4,10); the serine/threonine unlike the case of fat cells, GLUT4 expression is not sig- kinase PAK1 (7,11); and the small G protein Ral (12).
    [Show full text]
  • Structural Basis of the Interaction Between Rala and Sec5, a Subunit of the Sec6/8 Complex
    The EMBO Journal Vol. 22 No. 13 pp. 3267±3278, 2003 Structural basis of the interaction between RalA and Sec5, a subunit of the sec6/8 complex Shuya Fukai, Hugo T.Matern1, membrane fusion. The tethering step is de®ned as the Junutula R.Jagath1, Richard H.Scheller1 and initial contact of the vesicle via a protein bridge with its Axel T.Brunger2 target compartment and is the critical determinant in the speci®city of membrane fusion. Essential for this tethering Howard Hughes Medical Institute and Departments of Molecular and are multimeric protein complexes that have been shown to Cellular Physiology, Neurology and Neurological Sciences and Stanford Synchrotron Radiation Laboratory, Stanford University, be involved in most, if not all, intracellular traf®cking James H.Clark Center, E300C, 318 Campus Drive, Stanford, CA events (Whyte and Munro, 2002). 94305-5432 and 1Genentech Inc., 1 DNA Way, South San Francisco, The tethering complex for exocytosis at the plasma CA 94080, USA membrane is referred to as the sec6/8 complex or exocyst 2Corresponding author in yeast (TerBush et al., 1996; Kee et al., 1997). This e-mail: [email protected] hetero-octameric protein complex is composed of the original SEC gene products (Sec3, Sec5, Sec6, Sec8, The sec6/8 complex or exocyst is an octameric protein Sec10, Sec15), plus Exo70 and Exo84. The exocyst complex that functions during cell polarization by components were originally identi®ed in a yeast genetic regulating the site of exocytic vesicle docking to the screen for mutants that are de®cient in the fusion of plasma membrane, in concert with small GTP-binding secretory vesicles with the plasma membrane (TerBush proteins.
    [Show full text]
  • The Dual Role of Filamin a in Cancer: Can't Live with (Too Much
    R M Savoy and P M Ghosh Dual role of filamin A in cancer 20:6 R341–R356 Review The dual role of filamin A in cancer: can’t live with (too much of) it, can’t live without it Correspondence 1 1,2 Rosalinda M Savoy and Paramita M Ghosh should be addressed to P M Ghosh 1Department of Urology, University of California Davis School of Medicine, University of California, 4860 Y Street, Email Suite 3500, Sacramento, California 95817, USA Paramita.Ghosh@ 2VA Northern California Health Care System, Mather, California, USA ucdmc.ucdavis.edu Abstract Filamin A (FlnA) has been associated with actin as cytoskeleton regulator. Recently its role in Key Words the cell has come under scrutiny for FlnA’s involvement in cancer development. FlnA was " filamin A originally revealed as a cancer-promoting protein, involved in invasion and metastasis. " metastasis However, recent studies have also found that under certain conditions, it prevented tumor " cancer formation or progression, confusing the precise function of FlnA in cancer development. " transcription Here, we try to decipher the role of FlnA in cancer and the implications for its dual role. We " nucleus propose that differences in subcellular localization of FlnA dictate its role in cancer " cytoplasm development. In the cytoplasm, FlnA functions in various growth signaling pathways, such as " localization vascular endothelial growth factor, in addition to being involved in cell migration and adhesion pathways, such as R-Ras and integrin signaling. Involvement in these pathways and Endocrine-Related Cancer various others has shown a correlation between high cytoplasmic FlnA levels and invasive cancers.
    [Show full text]
  • Explicit Consideration of Solubility and Interaction Specificity In
    Explicit Consideration of Solubility and Interaction Specificity in Computational Protein Design Ronald Jerzy Jacak A dissertation submitted to the faculty of the University of North Carolina at Chapel Hill in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Department of Biochemistry and Biophysics. Chapel Hill 2011 Approved by: Advisor: Brian Kuhlman Reader: Sharon Campbell Reader: Charles Carter Reader: Channing Der Reader: Tim Elston c 2011 Ronald Jerzy Jacak ALL RIGHTS RESERVED ii Abstract Ronald Jerzy Jacak: Explicit Consideration of Solubility and Interaction Specificity in Computational Protein Design (Under the direction of Brian Kuhlman) Most successes to date in computational protein design have relied on optimizing sequences to fit well for a single structure. Multistate design represents a new approach to designing proteins in which sequences are optimized for multiple contexts usually given by multiple structures (states). In multistate design simulations, sequences that either stabilize the target state or destabilize alternate competing states are selected. This dissertation describes the application of multistate design to two problems in protein design: designing sequences for solubility and increasing binding specificity in protein-protein interface design. Previous studies with the modeling program Rosetta have shown that many designed proteins have patches of hydrophobic surface area that are considerably larger than what is seen in native proteins. These patches can lead to nonspecific association and aggregation. We use a multistate design approach to address protein solubility by disfavoring the aggregated state through the addition of a new solubility term to the Rosetta energy function. The score term explicitly detects and penalizes the formation of hydrophobic patches during design.
    [Show full text]
  • MED12 Is Recurrently Mutated in Middle Eastern Colorectal Cancer
    Gut Online First, published on February 9, 2017 as 10.1136/gutjnl-2016-313334 Colon ORIGINAL ARTICLE MED12 is recurrently mutated in Middle Eastern Gut: first published as 10.1136/gutjnl-2016-313334 on 9 February 2017. Downloaded from colorectal cancer Abdul K Siraj,1 Tariq Masoodi,1 Rong Bu,1 Poyil Pratheeshkumar,1 Nasser Al-Sanea,2 Luai H Ashari,2 Alaa Abduljabbar,2 Samar Alhomoud,2 Fouad Al-Dayel,3 Fowzan S Alkuraya,4,5 Khawla S Al-Kuraya1 ▸ Additional material is ABSTRACT published online only. To view Objective Colorectal cancer (CRC) is a common cancer Significance of this study please visit the journal online (http://dx.doi.org/10.1136/ and a leading cause of cancer deaths. Previous studies gutjnl-2016-313334). have identified a number of key steps in the evolution of CRC but our knowledge of driver mutations in CRC 1Human Cancer Genomic What is already known on this subject? Research, King Faisal Specialist remains incomplete. Recognising the potential of ▸ Colorectal cancer is known to develop as a Hospital and Research Centre, studying different human populations to reveal novel multistep process involving driver mutations. Riyadh, Saudi Arabia insights in disease pathogenesis, we conducted genomic ▸ 2 MED12 mutations are known to drive several Department of Surgery and analysis of CRC in Saudi patients. tumour types. Colorectal Section, King Faisal Specialist Hospital and Design In the discovery phase of the study, we conducted whole genome sequencing of tumour and What are the new findings? Research Centre, Riyadh, ▸ Saudi Arabia corresponding germline DNA in 27 patients with CRC.
    [Show full text]
  • Cerebral Cavernous Malformations: from Genes to Proteins to Disease
    See the corresponding editorial in this issue, pp 119–121. J Neurosurg 116:122–132, 2012 Cerebral cavernous malformations: from genes to proteins to disease Clinical article DANIEL D. CAVALCANTI, M.D., M. YASHAR S. KALANI, M.D., PH.D., NIKOLAY L. MARTIROSYAN, M.D., JUSTIN EALES, B.S., ROBERT F. SPETZLER, M.D., AND MARK C. PREUL, M.D. Division of Neurological Surgery, Barrow Neurological Institute, St. Joseph’s Hospital and Medical Center, Phoenix, Arizona Over the past half century molecular biology has led to great advances in our understanding of angio- and vas- culogenesis and in the treatment of malformations resulting from these processes gone awry. Given their sporadic and familial distribution, their developmental and pathological link to capillary telangiectasias, and their observed chromosomal abnormalities, cerebral cavernous malformations (CCMs) are regarded as akin to cancerous growths. Although the exact pathological mechanisms involved in the formation of CCMs are still not well understood, the identification of 3 genetic loci has begun to shed light on key developmental pathways involved in CCM pathogen- esis. Cavernous malformations can occur sporadically or in an autosomal dominant fashion. Familial forms of CCMs have been attributed to mutations at 3 different loci implicated in regulating important processes such as proliferation and differentiation of angiogenic precursors and members of the apoptotic machinery. These processes are important for the generation, maintenance, and pruning of every vessel in the body. In this review the authors highlight the lat- est discoveries pertaining to the molecular genetics of CCMs, highlighting potential new therapeutic targets for the treatment of these lesions.
    [Show full text]
  • Transcriptional Recapitulation and Subversion Of
    Open Access Research2007KaiseretVolume al. 8, Issue 7, Article R131 Transcriptional recapitulation and subversion of embryonic colon comment development by mouse colon tumor models and human colon cancer Sergio Kaiser¤*, Young-Kyu Park¤†, Jeffrey L Franklin†, Richard B Halberg‡, Ming Yu§, Walter J Jessen*, Johannes Freudenberg*, Xiaodi Chen‡, Kevin Haigis¶, Anil G Jegga*, Sue Kong*, Bhuvaneswari Sakthivel*, Huan Xu*, Timothy Reichling¥, Mohammad Azhar#, Gregory P Boivin**, reviews Reade B Roberts§, Anika C Bissahoyo§, Fausto Gonzales††, Greg C Bloom††, Steven Eschrich††, Scott L Carter‡‡, Jeremy E Aronow*, John Kleimeyer*, Michael Kleimeyer*, Vivek Ramaswamy*, Stephen H Settle†, Braden Boone†, Shawn Levy†, Jonathan M Graff§§, Thomas Doetschman#, Joanna Groden¥, William F Dove‡, David W Threadgill§, Timothy J Yeatman††, reports Robert J Coffey Jr† and Bruce J Aronow* Addresses: *Biomedical Informatics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA. †Departments of Medicine, and Cell and Developmental Biology, Vanderbilt University and Department of Veterans Affairs Medical Center, Nashville, TN 37232, USA. ‡McArdle Laboratory for Cancer Research, University of Wisconsin, Madison, WI 53706, USA. §Department of Genetics and Lineberger Cancer Center, University of North Carolina, Chapel Hill, NC 27599, USA. ¶Molecular Pathology Unit and Center for Cancer Research, Massachusetts deposited research General Hospital, Charlestown, MA 02129, USA. ¥Division of Human Cancer Genetics, The Ohio State University College of Medicine, Columbus, Ohio 43210-2207, USA. #Institute for Collaborative BioResearch, University of Arizona, Tucson, AZ 85721-0036, USA. **University of Cincinnati, Department of Pathology and Laboratory Medicine, Cincinnati, OH 45267, USA. ††H Lee Moffitt Cancer Center and Research Institute, Tampa, FL 33612, USA. ‡‡Children's Hospital Informatics Program at the Harvard-MIT Division of Health Sciences and Technology (CHIP@HST), Harvard Medical School, Boston, Massachusetts 02115, USA.
    [Show full text]
  • Phospholipase D in Cell Proliferation and Cancer
    Vol. 1, 789–800, September 2003 Molecular Cancer Research 789 Subject Review Phospholipase D in Cell Proliferation and Cancer David A. Foster and Lizhong Xu The Department of Biological Sciences, Hunter College of The City University of New York, New York, NY Abstract trafficking, cytoskeletal reorganization, receptor endocytosis, Phospholipase D (PLD) has emerged as a regulator of exocytosis, and cell migration (4, 5). A role for PLD in cell several critical aspects of cell physiology. PLD, which proliferation is indicated from reports showing that PLD catalyzes the hydrolysis of phosphatidylcholine (PC) to activity is elevated in response to platelet-derived growth factor phosphatidic acid (PA) and choline, is activated in (PDGF; 6), fibroblast growth factor (7, 8), epidermal growth response to stimulators of vesicle transport, endocyto- factor (EGF; 9), insulin (10), insulin-like growth factor 1 (11), sis, exocytosis, cell migration, and mitosis. Dysregula- growth hormone (12), and sphingosine 1-phosphate (13). PLD tion of these cell biological processes occurs in the activity is also elevated in cells transformed by a variety development of a variety of human tumors. It has now of transforming oncogenes including v-Src (14), v-Ras (15, 16), been observed that there are abnormalities in PLD v-Fps (17), and v-Raf (18). Thus, there is a growing body of expression and activity in many human cancers. In this evidence linking PLD activity with mitogenic signaling. While review, evidence is summarized implicating PLD as a PLD has been associated with many aspects of cell physiology critical regulator of cell proliferation, survival signaling, such as membrane trafficking and cytoskeletal organization cell transformation, and tumor progression.
    [Show full text]
  • Regulated Ralbp1 Binding to Rala and PSD-95 Controls AMPA Receptor Endocytosis and LTD
    Regulated RalBP1 Binding to RalA and PSD-95 Controls AMPA Receptor Endocytosis and LTD The MIT Faculty has made this article openly available. Please share how this access benefits you. Your story matters. Citation Han K, Kim M-H, Seeburg D, Seo J, Verpelli C, et al. (2009) Regulated RalBP1 Binding to RalA and PSD-95 Controls AMPA Receptor Endocytosis and LTD. PLoS Biol 7(9): e1000187. doi:10.1371/journal.pbio.1000187 As Published http://dx.doi.org/10.1371/journal.pbio.1000187 Publisher Public Library of Science Version Final published version Citable link http://hdl.handle.net/1721.1/52609 Terms of Use Creative Commons Attribution Detailed Terms http://creativecommons.org/licenses/by/2.5/ Regulated RalBP1 Binding to RalA and PSD-95 Controls AMPA Receptor Endocytosis and LTD Kihoon Han1., Myoung-Hwan Kim1., Daniel Seeburg2,3, Jinsoo Seo4, Chiara Verpelli5, Seungnam Han1, Hye Sun Chung6, Jaewon Ko1, Hyun Woo Lee1, Karam Kim1, Won Do Heo1, Tobias Meyer7, Hyun Kim6, Carlo Sala5, Se-Young Choi4, Morgan Sheng2,3, Eunjoon Kim1¤* 1 National Creative Research Initiative Center for Synaptogenesis and Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Korea, 2 The Picower Institute for Learning and Memory, RIKEN-MIT Neuroscience Research Center, 3 Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America, 4 Department of Physiology and Dental Research Institute, Seoul National University School of Dentistry, Seoul, Korea, 5 CNR Institute of Neuroscience and Department of Neurological Sciences, University of Milan, Milan, Italy, 6 Department of Anatomy and Division of Brain Korea 21 Biomedical Science, College of Medicine, Korea University, Seoul, Korea, 7 Department of Chemical and Systems Biology, Stanford University, Stanford, California, United States of America Abstract Long-term depression (LTD) is a long-lasting activity-dependent decrease in synaptic strength.
    [Show full text]
  • The Small G-Protein Rala Promotes Progression and Metastasis of Triple- Negative Breast Cancer Katie A
    Thies et al. Breast Cancer Research (2021) 23:65 https://doi.org/10.1186/s13058-021-01438-3 RESEARCH ARTICLE Open Access The small G-protein RalA promotes progression and metastasis of triple- negative breast cancer Katie A. Thies1,2, Matthew W. Cole1,2, Rachel E. Schafer1,2, Jonathan M. Spehar1,2, Dillon S. Richardson1,2, Sarah A. Steck1,2, Manjusri Das1,2, Arthur W. Lian1,2, Alo Ray1,2, Reena Shakya1,3, Sue E. Knoblaugh4, Cynthia D. Timmers5,6, Michael C. Ostrowski5,7, Arnab Chakravarti1,2, Gina M. Sizemore1,2 and Steven T. Sizemore1,2* Abstract Background: Breast cancer (BC) is the most common cancer in women and the leading cause of cancer-associated mortality in women. In particular, triple-negative BC (TNBC) has the highest rate of mortality due in large part to the lack of targeted treatment options for this subtype. Thus, there is an urgent need to identify new molecular targets for TNBC treatment. RALA and RALB are small GTPases implicated in growth and metastasis of a variety of cancers, although little is known of their roles in BC. Methods: The necessity of RALA and RALB for TNBC tumor growth and metastasis were evaluated in vivo using orthotopic and tail-vein models. In vitro, 2D and 3D cell culture methods were used to evaluate the contributions of RALA and RALB during TNBC cell migration, invasion, and viability. The association between TNBC patient outcome and RALA and RALB expression was examined using publicly available gene expression data and patient tissue microarrays. Finally, small molecule inhibition of RALA and RALB was evaluated as a potential treatment strategy for TNBC in cell line and patient-derived xenograft (PDX) models.
    [Show full text]
  • Systematic Elucidation of Neuron-Astrocyte Interaction in Models of Amyotrophic Lateral Sclerosis Using Multi-Modal Integrated Bioinformatics Workflow
    ARTICLE https://doi.org/10.1038/s41467-020-19177-y OPEN Systematic elucidation of neuron-astrocyte interaction in models of amyotrophic lateral sclerosis using multi-modal integrated bioinformatics workflow Vartika Mishra et al.# 1234567890():,; Cell-to-cell communications are critical determinants of pathophysiological phenotypes, but methodologies for their systematic elucidation are lacking. Herein, we propose an approach for the Systematic Elucidation and Assessment of Regulatory Cell-to-cell Interaction Net- works (SEARCHIN) to identify ligand-mediated interactions between distinct cellular com- partments. To test this approach, we selected a model of amyotrophic lateral sclerosis (ALS), in which astrocytes expressing mutant superoxide dismutase-1 (mutSOD1) kill wild-type motor neurons (MNs) by an unknown mechanism. Our integrative analysis that combines proteomics and regulatory network analysis infers the interaction between astrocyte-released amyloid precursor protein (APP) and death receptor-6 (DR6) on MNs as the top predicted ligand-receptor pair. The inferred deleterious role of APP and DR6 is confirmed in vitro in models of ALS. Moreover, the DR6 knockdown in MNs of transgenic mutSOD1 mice attenuates the ALS-like phenotype. Our results support the usefulness of integrative, systems biology approach to gain insights into complex neurobiological disease processes as in ALS and posit that the proposed methodology is not restricted to this biological context and could be used in a variety of other non-cell-autonomous communication
    [Show full text]