1
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Xue Y, Krishnan A, Chahda JS, Schweickart RA, Sousa-Neves R, Mizutani CM. The epithelial polarity genes frazzled and GUK-holder adjust morphogen gradients to coordinate changes in cell position with cell fate specification. PLoS Biol 2023; 21:e3002021. [PMID: 36913435 PMCID: PMC10035841 DOI: 10.1371/journal.pbio.3002021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 03/23/2023] [Accepted: 02/03/2023] [Indexed: 03/14/2023] Open
Abstract
Morphogenetic gradients specify distinct cell populations within tissues. Originally, morphogens were conceived as substances that act on a static field of cells, yet cells usually move during development. Thus, the way cell fates are defined in moving cells remains a significant and largely unsolved problem. Here, we investigated this issue using spatial referencing of cells and 3D spatial statistics in the Drosophila blastoderm to reveal how cell density responds to morphogenetic activity. We show that the morphogen decapentaplegic (DPP) attracts cells towards its peak levels in the dorsal midline, whereas dorsal (DL) stalls them ventrally. We identified frazzled and GUK-holder as the downstream effectors regulated by these morphogens that constrict cells and provide the mechanical force necessary to draw cells dorsally. Surprisingly, GUKH and FRA modulate the DL and DPP gradient levels and this regulation creates a very precise mechanism of coordinating cell movement and fate specification.
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Affiliation(s)
- Yongqiang Xue
- Department of Biology, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Aravindan Krishnan
- Department of Biology, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Juan Sebastian Chahda
- Department of Biology, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Robert Allen Schweickart
- Department of Biology, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Rui Sousa-Neves
- Department of Genetics and Genome Sciences, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Claudia Mieko Mizutani
- Department of Biology, Case Western Reserve University, Cleveland, Ohio, United States of America
- Department of Genetics and Genome Sciences, Case Western Reserve University, Cleveland, Ohio, United States of America
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2
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Córdova-García G, Esquivel CJ, Pérez-Staples D, Ruiz-May E, Herrera-Cruz M, Reyes-Hernández M, Abraham S, Aluja M, Sirot L. Characterization of reproductive proteins in the Mexican fruit fly points towards the evolution of novel functions. Proc Biol Sci 2022; 289:20212806. [PMID: 35765836 PMCID: PMC9240691 DOI: 10.1098/rspb.2021.2806] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Seminal fluid proteins (Sfps) modify female phenotypes and have wide-ranging evolutionary implications on fitness in many insects. However, in the Mexican fruit fly, Anastrepha ludens, a highly destructive agricultural pest, the functions of Sfps are still largely unknown. To gain insights into female phenotypes regulated by Sfps, we used nano-liquid chromatography mass spectrometry to conduct a proteomic analysis of the soluble proteins from reproductive organs of A. ludens. The proteins predicted to be transferred from males to females during copulation were 100 proteins from the accessory glands, 69 from the testes and 20 from the ejaculatory bulb, resulting in 141 unique proteins after accounting for redundancies from multiple tissues. These 141 included orthologues to Drosophila melanogaster proteins involved mainly in oogenesis, spermatogenesis, immune response, lifespan and fecundity. In particular, we found one protein associated with female olfactory response to repellent stimuli (Scribble), and two related to memory formation (aPKC and Shibire). Together, these results raise the possibility that A. ludens Sfps could play a role in regulating female olfactory responses and memory formation and could be indicative of novel evolutionary functions in this important agricultural pest.
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Affiliation(s)
- Guadalupe Córdova-García
- INBIOTECA, Universidad Veracruzana, Av. de las Culturas Veracruzanas 101, Col. E. Zapata, Xalapa, CP 91090 Veracruz, México
| | | | - Diana Pérez-Staples
- INBIOTECA, Universidad Veracruzana, Av. de las Culturas Veracruzanas 101, Col. E. Zapata, Xalapa, CP 91090 Veracruz, México
| | - Eliel Ruiz-May
- Red de Manejo Biorracional de Plagas y Vectores, Clúster Científico y Tecnológico BioMimic®, Instituto de Ecología A.C. (INECOL), Antigua Carretera a Coatepec 351, Xalapa, Veracruz, México
| | - Mariana Herrera-Cruz
- Facultad de Medicina y Cirugía, Universidad Autónoma Benito Juárez de Oaxaca, Ex-Hda de Aguilera S/N, C.P. 68020, Oaxaca, Oaxaca, México
| | - Martha Reyes-Hernández
- Universidad Autónoma de Guadalajara, Av. Patria 1201, Col. Lomas del Valle, CP 45129 Zapopan, Jalisco, México
| | - Solana Abraham
- Laboratorio de Investigaciones Ecoetológicas de Moscas de la Fruta y sus Enemigos Naturales (LIEMEN), PROIMI-Biotecnología, CONICET, Avenida Belgrano y Pasaje Caseros s/n, CP 4000 San Miguel de Tucumán, Tucumán, Argentina
| | - Martín Aluja
- Red de Manejo Biorracional de Plagas y Vectores, Clúster Científico y Tecnológico BioMimic®, Instituto de Ecología A.C. (INECOL), Antigua Carretera a Coatepec 351, Xalapa, Veracruz, México
| | - Laura Sirot
- Department of Biology, College of Wooster, 931 College Mall, Wooster, OH 44691, USA
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3
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Khoury MJ, Bilder D. Minimal functional domains of the core polarity regulator Dlg. Biol Open 2022; 11:276053. [PMID: 35722710 PMCID: PMC9346270 DOI: 10.1242/bio.059408] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 06/14/2022] [Indexed: 11/20/2022] Open
Abstract
The compartmentalized domains of polarized epithelial cells arise from mutually antagonistic actions between the apical Par complex and the basolateral Scrib module. In Drosophila, the Scrib module proteins Scribble (Scrib) and Discs-large (Dlg) are required to limit Lgl phosphorylation at the basolateral cortex, but how Scrib and Dlg could carry out such a ‘protection’ activity is not clear. We tested Protein Phosphatase 1α (PP1) as a potential mediator of this activity, but demonstrate that a significant component of Scrib and Dlg regulation of Lgl is PP1 independent, and found no evidence for a Scrib-Dlg-PP1 protein complex. However, the Dlg SH3 domain plays a role in Lgl protection and, in combination with the N-terminal region of the Dlg HOOK domain, in recruitment of Scrib to the membrane. We identify a ‘minimal Dlg’ comprised of the SH3 and HOOK domains that is both necessary and sufficient for Scrib localization and epithelial polarity function in vivo. This article has an associated First Person interview with the first author of the paper. Summary: A minimal SH3-HOOK fragment of Dlg is sufficient to support epithelial polarity through mechanisms independent of the PP1 phosphatase.
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Affiliation(s)
- Mark J Khoury
- Department of Molecular and Cell Biology, University of California-Berkeley, Berkeley CA 94720, USA
| | - David Bilder
- Department of Molecular and Cell Biology, University of California-Berkeley, Berkeley CA 94720, USA
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4
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Kroll JR, Remmelzwaal S, Boxem M. CeLINC, a fluorescence-based protein-protein interaction assay in Caenorhabditis elegans. Genetics 2021; 219:6380436. [PMID: 34849800 PMCID: PMC8664570 DOI: 10.1093/genetics/iyab163] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Accepted: 09/22/2021] [Indexed: 11/30/2022] Open
Abstract
Interactions among proteins are fundamental for life and determining whether two particular proteins physically interact can be essential for fully understanding a protein’s function. We present Caenorhabditis elegans light-induced coclustering (CeLINC), an optical binary protein–protein interaction assay to determine whether two proteins interact in vivo. Based on CRY2/CIB1 light-dependent oligomerization, CeLINC can rapidly and unambiguously identify protein–protein interactions between pairs of fluorescently tagged proteins. A fluorescently tagged bait protein is captured using a nanobody directed against the fluorescent protein (GFP or mCherry) and brought into artificial clusters within the cell. Colocalization of a fluorescently tagged prey protein in the cluster indicates a protein interaction. We tested the system with an array of positive and negative reference protein pairs. Assay performance was extremely robust with no false positives detected in the negative reference pairs. We then used the system to test for interactions among apical and basolateral polarity regulators. We confirmed interactions seen between PAR-6, PKC-3, and PAR-3, but observed no physical interactions among the basolateral Scribble module proteins LET-413, DLG-1, and LGL-1. We have generated a plasmid toolkit that allows use of custom promoters or CRY2 variants to promote flexibility of the system. The CeLINC assay is a powerful and rapid technique that can be widely applied in C. elegans due to the universal plasmids that can be used with existing fluorescently tagged strains without need for additional cloning or genetic modification of the genome.
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Affiliation(s)
- Jason R Kroll
- Division of Developmental Biology, Department of Biology, Faculty of Science, Institute of Biodynamics and Biocomplexity, Utrecht University, 3584 CH Utrecht, the Netherlands
| | - Sanne Remmelzwaal
- Division of Developmental Biology, Department of Biology, Faculty of Science, Institute of Biodynamics and Biocomplexity, Utrecht University, 3584 CH Utrecht, the Netherlands
| | - Mike Boxem
- Division of Developmental Biology, Department of Biology, Faculty of Science, Institute of Biodynamics and Biocomplexity, Utrecht University, 3584 CH Utrecht, the Netherlands
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5
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Law AL, Jalal S, Pallett T, Mosis F, Guni A, Brayford S, Yolland L, Marcotti S, Levitt JA, Poland SP, Rowe-Sampson M, Jandke A, Köchl R, Pula G, Ameer-Beg SM, Stramer BM, Krause M. Nance-Horan Syndrome-like 1 protein negatively regulates Scar/WAVE-Arp2/3 activity and inhibits lamellipodia stability and cell migration. Nat Commun 2021; 12:5687. [PMID: 34584076 PMCID: PMC8478917 DOI: 10.1038/s41467-021-25916-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Accepted: 09/03/2021] [Indexed: 12/02/2022] Open
Abstract
Cell migration is important for development and its aberrant regulation contributes to many diseases. The Scar/WAVE complex is essential for Arp2/3 mediated lamellipodia formation during mesenchymal cell migration and several coinciding signals activate it. However, so far, no direct negative regulators are known. Here we identify Nance-Horan Syndrome-like 1 protein (NHSL1) as a direct binding partner of the Scar/WAVE complex, which co-localise at protruding lamellipodia. This interaction is mediated by the Abi SH3 domain and two binding sites in NHSL1. Furthermore, active Rac binds to NHSL1 at two regions that mediate leading edge targeting of NHSL1. Surprisingly, NHSL1 inhibits cell migration through its interaction with the Scar/WAVE complex. Mechanistically, NHSL1 may reduce cell migration efficiency by impeding Arp2/3 activity, as measured in cells using a Arp2/3 FRET-FLIM biosensor, resulting in reduced F-actin density of lamellipodia, and consequently impairing the stability of lamellipodia protrusions.
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Affiliation(s)
- Ah-Lai Law
- Krause Group, Randall Centre for Cell and Molecular Biophysics, King's College London, New Hunt's House, Guy's Campus, London, SE1 1UL, UK
- School of Life Sciences, University of Bedfordshire, Luton, LU1 3JU, UK
| | - Shamsinar Jalal
- Krause Group, Randall Centre for Cell and Molecular Biophysics, King's College London, New Hunt's House, Guy's Campus, London, SE1 1UL, UK
| | - Tommy Pallett
- Krause Group, Randall Centre for Cell and Molecular Biophysics, King's College London, New Hunt's House, Guy's Campus, London, SE1 1UL, UK
| | - Fuad Mosis
- Krause Group, Randall Centre for Cell and Molecular Biophysics, King's College London, New Hunt's House, Guy's Campus, London, SE1 1UL, UK
| | - Ahmad Guni
- Krause Group, Randall Centre for Cell and Molecular Biophysics, King's College London, New Hunt's House, Guy's Campus, London, SE1 1UL, UK
| | - Simon Brayford
- Stramer Group, Randall Centre for Cell and Molecular Biophysics, King's College London, New Hunt's House, Guy's Campus, London, SE1 1UL, UK
| | - Lawrence Yolland
- Stramer Group, Randall Centre for Cell and Molecular Biophysics, King's College London, New Hunt's House, Guy's Campus, London, SE1 1UL, UK
| | - Stefania Marcotti
- Stramer Group, Randall Centre for Cell and Molecular Biophysics, King's College London, New Hunt's House, Guy's Campus, London, SE1 1UL, UK
| | - James A Levitt
- Ameer-Beg Group, Richard Dimbleby Cancer Research Laboratories, Comprehensive Cancer Centre, School of Cancer and Pharmaceutical Sciences, King's College London, New Hunt's House, Guy's Campus, London, SE1 1UL, UK
| | - Simon P Poland
- Ameer-Beg Group, Richard Dimbleby Cancer Research Laboratories, Comprehensive Cancer Centre, School of Cancer and Pharmaceutical Sciences, King's College London, New Hunt's House, Guy's Campus, London, SE1 1UL, UK
| | - Maia Rowe-Sampson
- Krause Group, Randall Centre for Cell and Molecular Biophysics, King's College London, New Hunt's House, Guy's Campus, London, SE1 1UL, UK
- Stramer Group, Randall Centre for Cell and Molecular Biophysics, King's College London, New Hunt's House, Guy's Campus, London, SE1 1UL, UK
| | - Anett Jandke
- Krause Group, Randall Centre for Cell and Molecular Biophysics, King's College London, New Hunt's House, Guy's Campus, London, SE1 1UL, UK
- Immunosurveillance Laboratory, The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK
| | - Robert Köchl
- School of Immunology and Microbial Sciences, King's College London, Guy's Campus, London, SE1 1UL, UK
| | - Giordano Pula
- Krause Group, Randall Centre for Cell and Molecular Biophysics, King's College London, New Hunt's House, Guy's Campus, London, SE1 1UL, UK
- Institute for Clinical Chemistry and Laboratory Medicine, University Medical Center Hamburg (UKE), Martinistrasse 52, O26, 20246, Hamburg, Germany
| | - Simon M Ameer-Beg
- Ameer-Beg Group, Richard Dimbleby Cancer Research Laboratories, Comprehensive Cancer Centre, School of Cancer and Pharmaceutical Sciences, King's College London, New Hunt's House, Guy's Campus, London, SE1 1UL, UK
| | - Brian Marc Stramer
- Stramer Group, Randall Centre for Cell and Molecular Biophysics, King's College London, New Hunt's House, Guy's Campus, London, SE1 1UL, UK
| | - Matthias Krause
- Krause Group, Randall Centre for Cell and Molecular Biophysics, King's College London, New Hunt's House, Guy's Campus, London, SE1 1UL, UK.
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6
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Abedrabbo M, Ravid S. Scribble, Lgl1, and myosin II form a complex in vivo to promote directed cell migration. Mol Biol Cell 2020; 31:2234-2248. [PMID: 32697665 PMCID: PMC7550706 DOI: 10.1091/mbc.e19-11-0657] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Scribble (Scrib) and Lethal giant larvae 1 (Lgl1) are conserved polarity proteins that play important roles in different forms of cell polarity. The roles of Scrib and Lgl1 in apical-basal cell polarity have been studied extensively, but little is known about their roles in the cell polarity of migrating cells. Furthermore, the effect of Scrib and Lgl1 interaction on cell polarity is largely unknown. In this study, we show that Scrib, through its leucine-rich repeat domain, forms a complex in vivo with Lgl1. Scrib also forms a complex with myosin II, and Scrib, Lgl1, and myosin II colocalize at the leading edge of migrating cells. The cellular localization and the cytoskeletal association of Scrib and Lgl1 are interdependent, as depletion of either protein affects its counterpart. In addition, depletion of either Scrib or Lgl1 disrupts the cellular localization of myosin II. We show that depletion of either Scrib or Lgl1 affects cell adhesion through the inhibition of focal adhesion disassembly. Finally, we show that Scrib and Lgl1 are required for proper cell polarity of migrating cells. These results provide new insights into the mechanism regulating the cell polarity of migrating cells by Scrib, Lgl1, and myosin II.
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Affiliation(s)
- Maha Abedrabbo
- Department of Biochemistry and Molecular Biology, The Institute of Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem 91120, Israel
| | - Shoshana Ravid
- Department of Biochemistry and Molecular Biology, The Institute of Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem 91120, Israel
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7
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Schmidt A, Peifer M. Scribble and Dlg organize a protection racket to ensure apical-basal polarity. Proc Natl Acad Sci U S A 2020; 117:13188-13190. [PMID: 32471949 PMCID: PMC7306729 DOI: 10.1073/pnas.2007739117] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Anja Schmidt
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Mark Peifer
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599;
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
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8
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Jossin Y. Molecular mechanisms of cell polarity in a range of model systems and in migrating neurons. Mol Cell Neurosci 2020; 106:103503. [PMID: 32485296 DOI: 10.1016/j.mcn.2020.103503] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 04/20/2020] [Accepted: 05/23/2020] [Indexed: 01/09/2023] Open
Abstract
Cell polarity is defined as the asymmetric distribution of cellular components along an axis. Most cells, from the simplest single-cell organisms to highly specialized mammalian cells, are polarized and use similar mechanisms to generate and maintain polarity. Cell polarity is important for cells to migrate, form tissues, and coordinate activities. During development of the mammalian cerebral cortex, cell polarity is essential for neurogenesis and for the migration of newborn but as-yet undifferentiated neurons. These oriented migrations include both the radial migration of excitatory projection neurons and the tangential migration of inhibitory interneurons. In this review, I will first describe the development of the cerebral cortex, as revealed at the cellular level. I will then define the core molecular mechanisms - the Par/Crb/Scrib polarity complexes, small GTPases, the actin and microtubule cytoskeletons, and phosphoinositides/PI3K signaling - that are required for asymmetric cell division, apico-basal and front-rear polarity in model systems, including C elegans zygote, Drosophila embryos and cultured mammalian cells. As I go through each core mechanism I will explain what is known about its importance in radial and tangential migration in the developing mammalian cerebral cortex.
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Affiliation(s)
- Yves Jossin
- Laboratory of Mammalian Development & Cell Biology, Institute of Neuroscience, Université Catholique de Louvain, Brussels, Belgium.
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9
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Khoury MJ, Bilder D. Distinct activities of Scrib module proteins organize epithelial polarity. Proc Natl Acad Sci U S A 2020; 117:11531-11540. [PMID: 32414916 PMCID: PMC7260944 DOI: 10.1073/pnas.1918462117] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
A polarized architecture is central to both epithelial structure and function. In many cells, polarity involves mutual antagonism between the Par complex and the Scribble (Scrib) module. While molecular mechanisms underlying Par-mediated apical determination are well-understood, how Scrib module proteins specify the basolateral domain remains unknown. Here, we demonstrate dependent and independent activities of Scrib, Discs-large (Dlg), and Lethal giant larvae (Lgl) using the Drosophila follicle epithelium. Our data support a linear hierarchy for localization, but rule out previously proposed protein-protein interactions as essential for polarization. Cortical recruitment of Scrib does not require palmitoylation or polar phospholipid binding but instead an independent cortically stabilizing activity of Dlg. Scrib and Dlg do not directly antagonize atypical protein kinase C (aPKC), but may instead restrict aPKC localization by enabling the aPKC-inhibiting activity of Lgl. Importantly, while Scrib, Dlg, and Lgl are each required, all three together are not sufficient to antagonize the Par complex. Our data demonstrate previously unappreciated diversity of function within the Scrib module and begin to define the elusive molecular functions of Scrib and Dlg.
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Affiliation(s)
- Mark J Khoury
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720
| | - David Bilder
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720
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10
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Carmena A. The Case of the Scribble Polarity Module in Asymmetric Neuroblast Division in Development and Tumorigenesis. Int J Mol Sci 2020; 21:ijms21082865. [PMID: 32325951 PMCID: PMC7215838 DOI: 10.3390/ijms21082865] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 04/16/2020] [Accepted: 04/17/2020] [Indexed: 12/29/2022] Open
Abstract
The Scribble polarity module is composed by Scribble (Scrib), Discs large 1 (Dlg1) and Lethal (2) giant larvae (L(2)gl), a group of highly conserved neoplastic tumor suppressor genes (TSGs) from flies to humans. Even though the Scribble module has been profusely studied in epithelial cell polarity, the number of tissues and processes in which it is involved is increasingly growing. Here we discuss the role of the Scribble module in the asymmetric division of Drosophila neuroblasts (NBs), as well as the underlying mechanisms by which those TSGs act in this process. Finally, we also describe what we know about the consequences of mutating these genes in impairing the process of asymmetric NB division and promoting tumor-like overgrowth.
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Affiliation(s)
- Ana Carmena
- Instituto de Neurociencias, Consejo Superior de Investigaciones Científicas/Universidad Miguel Hernández, 03550 Sant Joan d'Alacant, Alicante, Spain
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11
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Bonello TT, Choi W, Peifer M. Scribble and Discs-large direct initial assembly and positioning of adherens junctions during the establishment of apical-basal polarity. Development 2019; 146:dev.180976. [PMID: 31628110 DOI: 10.1242/dev.180976] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Accepted: 10/14/2019] [Indexed: 01/05/2023]
Abstract
Apical-basal polarity is a fundamental property of animal tissues. Drosophila embryos provide an outstanding model for defining mechanisms that initiate and maintain polarity. Polarity is initiated during cellularization, when cell-cell adherens junctions are positioned at the future boundary of apical and basolateral domains. Polarity maintenance then involves complementary and antagonistic interplay between apical and basal polarity complexes. The Scribble/Dlg module is well-known for promoting basolateral identity during polarity maintenance. Here, we report a surprising role for Scribble/Dlg in polarity initiation, placing it near the top of the network-positioning adherens junctions. Scribble and Dlg are enriched in nascent adherens junctions, are essential for adherens junction positioning and supermolecular assembly, and also play a role in basal junction assembly. We test the hypotheses for the underlying mechanisms, exploring potential effects on protein trafficking, cytoskeletal polarity or Par-1 localization/function. Our data suggest that the Scribble/Dlg module plays multiple roles in polarity initiation. Different domains of Scribble contribute to these distinct roles. Together, these data reveal novel roles for Scribble/Dlg as master scaffolds regulating assembly of distinct junctional complexes at different times and places.
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Affiliation(s)
- Teresa T Bonello
- Department of Biology, University of North Carolina at Chapel Hill, CB#3280, Chapel Hill, NC 27599-3280, USA
| | - Wangsun Choi
- Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Mark Peifer
- Department of Biology, University of North Carolina at Chapel Hill, CB#3280, Chapel Hill, NC 27599-3280, USA .,Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.,Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
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12
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Janezic EM, Harris DA, Dinh D, Lee KS, Stewart A, Hinds TR, Hsu PL, Zheng N, Hague C. Scribble co-operatively binds multiple α 1D-adrenergic receptor C-terminal PDZ ligands. Sci Rep 2019; 9:14073. [PMID: 31575922 PMCID: PMC6773690 DOI: 10.1038/s41598-019-50671-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Accepted: 09/17/2019] [Indexed: 01/17/2023] Open
Abstract
Many G protein-coupled receptors (GPCRs) are organized as dynamic macromolecular complexes in human cells. Unraveling the structural determinants of unique GPCR complexes may identify unique protein:protein interfaces to be exploited for drug development. We previously reported α1D-adrenergic receptors (α1D-ARs) – key regulators of cardiovascular and central nervous system function – form homodimeric, modular PDZ protein complexes with cell-type specificity. Towards mapping α1D-AR complex architecture, biolayer interferometry (BLI) revealed the α1D-AR C-terminal PDZ ligand selectively binds the PDZ protein scribble (SCRIB) with >8x higher affinity than known interactors syntrophin, CASK and DLG1. Complementary in situ and in vitro assays revealed SCRIB PDZ domains 1 and 4 to be high affinity α1D-AR PDZ ligand interaction sites. SNAP-GST pull-down assays demonstrate SCRIB binds multiple α1D-AR PDZ ligands via a co-operative mechanism. Structure-function analyses pinpoint R1110PDZ4 as a unique, critical residue dictating SCRIB:α1D-AR binding specificity. The crystal structure of SCRIB PDZ4 R1110G predicts spatial shifts in the SCRIB PDZ4 carboxylate binding loop dictate α1D-AR binding specificity. Thus, the findings herein identify SCRIB PDZ domains 1 and 4 as high affinity α1D-AR interaction sites, and potential drug targets to treat diseases associated with aberrant α1D-AR signaling.
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Affiliation(s)
- Eric M Janezic
- Department of Pharmacology, School of Medicine, University of Washington, 1959 NE Pacific Street, Seattle, WA, 98195, USA
| | - Dorathy-Ann Harris
- Department of Pharmacology, School of Medicine, University of Washington, 1959 NE Pacific Street, Seattle, WA, 98195, USA
| | - Diana Dinh
- Department of Pharmacology, School of Medicine, University of Washington, 1959 NE Pacific Street, Seattle, WA, 98195, USA
| | - Kyung-Soon Lee
- Department of Pharmacology, School of Medicine, University of Washington, 1959 NE Pacific Street, Seattle, WA, 98195, USA
| | - Aaron Stewart
- Department of Pharmacology, School of Medicine, University of Washington, 1959 NE Pacific Street, Seattle, WA, 98195, USA
| | - Thomas R Hinds
- Department of Pharmacology, School of Medicine, University of Washington, 1959 NE Pacific Street, Seattle, WA, 98195, USA
| | - Peter L Hsu
- Department of Pharmacology, School of Medicine, University of Washington, 1959 NE Pacific Street, Seattle, WA, 98195, USA.,Howard Hughes Medical Institute, University of Washington, Seattle, WA, 98195, USA
| | - Ning Zheng
- Department of Pharmacology, School of Medicine, University of Washington, 1959 NE Pacific Street, Seattle, WA, 98195, USA.,Howard Hughes Medical Institute, University of Washington, Seattle, WA, 98195, USA
| | - Chris Hague
- Department of Pharmacology, School of Medicine, University of Washington, 1959 NE Pacific Street, Seattle, WA, 98195, USA.
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13
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Sharifkhodaei Z, Gilbert MM, Auld VJ. Scribble and Discs Large mediate tricellular junction formation. Development 2019; 146:dev.174763. [PMID: 31444218 DOI: 10.1242/dev.174763] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Accepted: 08/15/2019] [Indexed: 01/22/2023]
Abstract
Junctional complexes that mediate cell adhesion are key to epithelial integrity, cell division and permeability barrier formation. In Drosophila, the scaffolding proteins Scribble (Scrib) and Discs Large (Dlg) are key regulators of epithelial polarity, proliferation, assembly of junctions and protein trafficking. We found that Scrib and Dlg are necessary for the formation of the tricellular junction (TCJ), a unique junction that forms in epithelia at the point of convergence of three neighboring cells. Scrib and Dlg are in close proximity with the TCJ proteins Gliotactin (Gli) and Bark Beetle (Bark), and both are required for TCJ protein recruitment. Loss of Bark or Gli led to basolateral spread of the TCJ complex at the cell corners. Loss of the septate junction proteins Nrx-IV and the Na+/K+ ATPase also resulted in basolateral spread of the entire TCJ complex at the cell corners. The Scrib PDZ1-2 domains and the Dlg GUK domain are necessary for Bark and Gli localization to the TCJ. Overall, we propose a model in which Scrib and Dlg are key components of the TCJ, and form a complex with Bark and Gli.
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Affiliation(s)
- Zohreh Sharifkhodaei
- Department of Zoology, University of British Columbia, Vancouver V6T 1Z4, Canada
| | - Mary M Gilbert
- Department of Zoology, University of British Columbia, Vancouver V6T 1Z4, Canada
| | - Vanessa J Auld
- Department of Zoology, University of British Columbia, Vancouver V6T 1Z4, Canada
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14
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New insights into apical-basal polarization in epithelia. Curr Opin Cell Biol 2019; 62:1-8. [PMID: 31505411 DOI: 10.1016/j.ceb.2019.07.017] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 07/25/2019] [Accepted: 07/26/2019] [Indexed: 11/21/2022]
Abstract
The establishment of an apical-basal axis of polarity is essential for the organization and functioning of epithelial cells. Polarization of epithelial cells is orchestrated by a network of conserved polarity regulators that establish opposing cortical domains through mutually antagonistic interactions and positive feedback loops. While our understanding is still far from complete, the molecular details behind these interactions continue to be worked out. Here, we highlight recent findings on the mechanisms that control the activity and localization of apical-basal polarity regulators, including oligomerization and higher-order complex formation, auto-inhibitory interactions, and electrostatic interactions with the plasma membrane.
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15
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Awadia S, Huq F, Arnold TR, Goicoechea SM, Sun YJ, Hou T, Kreider-Letterman G, Massimi P, Banks L, Fuentes EJ, Miller AL, Garcia-Mata R. SGEF forms a complex with Scribble and Dlg1 and regulates epithelial junctions and contractility. J Cell Biol 2019; 218:2699-2725. [PMID: 31248911 PMCID: PMC6683736 DOI: 10.1083/jcb.201811114] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Revised: 03/18/2019] [Accepted: 04/12/2019] [Indexed: 01/15/2023] Open
Abstract
The canonical Scribble polarity complex is implicated in regulation of epithelial junctions and apical polarity. Here, we show that SGEF, a RhoG-specific GEF, forms a ternary complex with Scribble and Dlg1, two members of the Scribble complex. SGEF targets to apical junctions in a Scribble-dependent fashion and functions in the regulation of actomyosin-based contractility and barrier function at tight junctions as well as E-cadherin-mediated formation of adherens junctions. Surprisingly, SGEF does not control the establishment of polarity. However, in 3D cysts, SGEF regulates the formation of a single open lumen. Interestingly, SGEF's nucleotide exchange activity regulates the formation and maintenance of adherens junctions, and in cysts the number of lumens formed, whereas SGEF's scaffolding activity is critical for regulation of actomyosin contractility and lumen opening. We propose that SGEF plays a key role in coordinating junctional assembly and actomyosin contractility by bringing together Scribble and Dlg1 and targeting RhoG activation to cell-cell junctions.
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Affiliation(s)
- Sahezeel Awadia
- Department of Biological Sciences, The University of Toledo, Toledo, OH
| | - Farah Huq
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI
| | - Torey R Arnold
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI
| | | | - Young Joo Sun
- Department of Biochemistry, University of Iowa, Iowa City, IA
| | - Titus Hou
- Department of Biochemistry, University of Iowa, Iowa City, IA
| | | | - Paola Massimi
- International Center for Genetic Engineering and Biotechnology, Trieste, Italy
| | - Lawrence Banks
- International Center for Genetic Engineering and Biotechnology, Trieste, Italy
| | | | - Ann L Miller
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI
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16
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Fahey-Lozano N, La Marca JE, Portela M, Richardson HE. Drosophila Models of Cell Polarity and Cell Competition in Tumourigenesis. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1167:37-64. [PMID: 31520348 DOI: 10.1007/978-3-030-23629-8_3] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Cell competition is an important surveillance mechanism that measures relative fitness between cells in a tissue during development, homeostasis, and disease. Specifically, cells that are "less fit" (losers) are actively eliminated by relatively "more fit" (winners) neighbours, despite the less fit cells otherwise being able to survive in a genetically uniform tissue. Originally described in the epithelial tissues of Drosophila larval imaginal discs, cell competition has since been shown to occur in other epithelial and non-epithelial Drosophila tissues, as well as in mammalian model systems. Many genes and signalling pathways have been identified as playing conserved roles in the mechanisms of cell competition. Among them are genes required for the establishment and maintenance of apico-basal cell polarity: the Crumbs/Stardust/Patj (Crb/Sdt/Patj), Bazooka/Par-6/atypical Protein Kinase C (Baz/Par-6/aPKC), and Scribbled/Discs large 1/Lethal (2) giant larvae (Scrib/Dlg1/L(2)gl) modules. In this chapter, we describe the concepts and mechanisms of cell competition, with emphasis on the relationship between cell polarity proteins and cell competition, particularly the Scrib/Dlg1/L(2)gl module, since this is the best described module in this emerging field.
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Affiliation(s)
- Natasha Fahey-Lozano
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC, Australia
| | - John E La Marca
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC, Australia
| | - Marta Portela
- Department of Molecular, Cellular and Developmental Neurobiology, Cajal Institute (CSIC), Madrid, Spain
| | - Helena E Richardson
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC, Australia.
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17
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Bonello TT, Peifer M. Scribble: A master scaffold in polarity, adhesion, synaptogenesis, and proliferation. J Cell Biol 2018; 218:742-756. [PMID: 30598480 PMCID: PMC6400555 DOI: 10.1083/jcb.201810103] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Revised: 11/26/2018] [Accepted: 12/14/2018] [Indexed: 02/08/2023] Open
Abstract
Key events ranging from cell polarity to proliferation regulation to neuronal signaling rely on the assembly of multiprotein adhesion or signaling complexes at particular subcellular sites. Multidomain scaffolding proteins nucleate assembly and direct localization of these complexes, and the protein Scribble and its relatives in the LAP protein family provide a paradigm for this. Scribble was originally identified because of its role in apical-basal polarity and epithelial integrity in Drosophila melanogaster It is now clear that Scribble acts to assemble and position diverse multiprotein complexes in processes ranging from planar polarity to adhesion to oriented cell division to synaptogenesis. Here, we explore what we have learned about the mechanisms of action of Scribble in the context of its multiple known interacting partners and discuss how this knowledge opens new questions about the full range of Scribble protein partners and their structural and signaling roles.
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Affiliation(s)
- Teresa T Bonello
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - Mark Peifer
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC .,Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC.,Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC
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18
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Allam AH, Charnley M, Russell SM. Context-Specific Mechanisms of Cell Polarity Regulation. J Mol Biol 2018; 430:3457-3471. [PMID: 29886017 DOI: 10.1016/j.jmb.2018.06.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 06/04/2018] [Accepted: 06/04/2018] [Indexed: 12/31/2022]
Abstract
Cell polarity is an essential process shared by almost all animal tissues. Moreover, cell polarity enables cells to sense and respond to the cues provided by the neighboring cells and the surrounding microenvironment. These responses play a critical role in regulating key physiological processes, including cell migration, proliferation, differentiation, vesicle trafficking and immune responses. The polarity protein complexes regulating these interactions are highly evolutionarily conserved between vertebrates and invertebrates. Interestingly, these polarity complexes interact with each other and key signaling pathways in a cell-polarity context-dependent manner. However, the exact mechanisms by which these interactions take place are poorly understood. In this review, we will focus on the roles of the key polarity complexes SCRIB, PAR and Crumbs in regulating different forms of cell polarity, including epithelial cell polarity, cell migration, asymmetric cell division and the T-cell immunological synapse assembly and signaling.
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Affiliation(s)
- Amr H Allam
- Centre for Micro-Photonics, Faculty of Science, Engineering & Technology, Swinburne University of Technology, Hawthorn, Australia; Immune Signalling Laboratory, Peter MacCallum Cancer Centre, Parkville, Australia.
| | - Mirren Charnley
- Centre for Micro-Photonics, Faculty of Science, Engineering & Technology, Swinburne University of Technology, Hawthorn, Australia; Immune Signalling Laboratory, Peter MacCallum Cancer Centre, Parkville, Australia; Biointerface Engineering Group, Faculty of Science, Engineering and Technology, Swinburne University of Technology, Hawthorn, VIC, Australia.
| | - Sarah M Russell
- Centre for Micro-Photonics, Faculty of Science, Engineering & Technology, Swinburne University of Technology, Hawthorn, Australia; Immune Signalling Laboratory, Peter MacCallum Cancer Centre, Parkville, Australia; Department of Pathology, The University of Melbourne, Australia; Sir Peter MacCallum Department of Oncology, The University of Melbourne, Australia.
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19
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Stephens R, Lim K, Portela M, Kvansakul M, Humbert PO, Richardson HE. The Scribble Cell Polarity Module in the Regulation of Cell Signaling in Tissue Development and Tumorigenesis. J Mol Biol 2018; 430:3585-3612. [PMID: 29409995 DOI: 10.1016/j.jmb.2018.01.011] [Citation(s) in RCA: 86] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Revised: 01/19/2018] [Accepted: 01/19/2018] [Indexed: 01/22/2023]
Abstract
The Scribble cell polarity module, comprising Scribbled (Scrib), Discs-large (Dlg) and Lethal-2-giant larvae (Lgl), has a tumor suppressive role in mammalian epithelial cancers. The Scribble module proteins play key functions in the establishment and maintenance of different modes of cell polarity, as well as in the control of tissue growth, differentiation and directed cell migration, and therefore are major regulators of tissue development and homeostasis. Whilst molecular details are known regarding the roles of Scribble module proteins in cell polarity regulation, their precise mode of action in the regulation of other key cellular processes remains enigmatic. An accumulating body of evidence indicates that Scribble module proteins play scaffolding roles in the control of various signaling pathways, which are linked to the control of tissue growth, differentiation and cell migration. Multiple Scrib, Dlg and Lgl interacting proteins have been discovered, which are involved in diverse processes, however many function in the regulation of cellular signaling. Herein, we review the components of the Scrib, Dlg and Lgl protein interactomes, and focus on the mechanism by which they regulate cellular signaling pathways in metazoans, and how their disruption leads to cancer.
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Affiliation(s)
- Rebecca Stephens
- Department of Biochemistry and Genetics, La Trobe Institute of Molecular Science, La Trobe University, Melbourne, Victoria, Australia
| | - Krystle Lim
- Department of Biochemistry and Genetics, La Trobe Institute of Molecular Science, La Trobe University, Melbourne, Victoria, Australia
| | - Marta Portela
- Department of Molecular, Cellular and Developmental Neurobiology, Cajal Institute (CSIC), Avenida Doctor Arce, 37, Madrid 28002, Spain
| | - Marc Kvansakul
- Department of Biochemistry and Genetics, La Trobe Institute of Molecular Science, La Trobe University, Melbourne, Victoria, Australia
| | - Patrick O Humbert
- Department of Biochemistry and Genetics, La Trobe Institute of Molecular Science, La Trobe University, Melbourne, Victoria, Australia; Department of Biochemistry & Molecular Biology, University of Melbourne, Melbourne, Victoria 3010, Australia; Department of Pathology, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Helena E Richardson
- Department of Biochemistry and Genetics, La Trobe Institute of Molecular Science, La Trobe University, Melbourne, Victoria, Australia; Department of Biochemistry & Molecular Biology, University of Melbourne, Melbourne, Victoria 3010, Australia; Department of Anatomy & Neurobiology, University of Melbourne, Melbourne, Victoria 3010, Australia.
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20
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Caria S, Magtoto CM, Samiei T, Portela M, Lim KYB, How JY, Stewart BZ, Humbert PO, Richardson HE, Kvansakul M. Drosophila melanogaster Guk-holder interacts with the Scribbled PDZ1 domain and regulates epithelial development with Scribbled and Discs Large. J Biol Chem 2018; 293:4519-4531. [PMID: 29378849 DOI: 10.1074/jbc.m117.817528] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Revised: 01/22/2018] [Indexed: 11/06/2022] Open
Abstract
Epithelial cell polarity is controlled by components of the Scribble polarity module, and its regulation is critical for tissue architecture and cell proliferation and migration. In Drosophila melanogaster, the adaptor protein Guk-holder (Gukh) binds to the Scribbled (Scrib) and Discs Large (Dlg) components of the Scribble polarity module and plays an important role in the formation of neuromuscular junctions. However, Gukh's role in epithelial tissue formation and the molecular basis for the Scrib-Gukh interaction remain to be defined. We now show using isothermal titration calorimetry that the Scrib PDZ1 domain is the major site for an interaction with Gukh. Furthermore, we defined the structural basis of this interaction by determining the crystal structure of the Scrib PDZ1-Gukh complex. The C-terminal PDZ-binding motif of Gukh is located in the canonical ligand-binding groove of Scrib PDZ1 and utilizes an unusually extensive network of hydrogen bonds and ionic interactions to enable binding to PDZ1 with high affinity. We next examined the role of Gukh along with those of Scrib and Dlg in Drosophila epithelial tissues and found that Gukh is expressed in larval-wing and eye-epithelial tissues and co-localizes with Scrib and Dlg at the apical cell cortex. Importantly, we show that Gukh functions with Scrib and Dlg in the development of Drosophila epithelial tissues, with depletion of Gukh enhancing the eye- and wing-tissue defects caused by Scrib or Dlg depletion. Overall, our findings reveal that Scrib's PDZ1 domain functions in the interaction with Gukh and that the Scrib-Gukh interaction has a key role in epithelial tissue development in Drosophila.
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Affiliation(s)
- Sofia Caria
- From the Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria 3086
| | - Charlene M Magtoto
- From the Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria 3086.,Cell Cycle and Cancer Genetics Laboratory, Research Division, Peter MacCallum Cancer Centre, and.,Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, Victoria 3002, and
| | - Tinaz Samiei
- From the Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria 3086.,the Cell Cycle and Development Laboratory
| | - Marta Portela
- From the Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria 3086.,the Cell Cycle and Development Laboratory
| | - Krystle Y B Lim
- From the Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria 3086
| | - Jing Yuan How
- From the Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria 3086
| | - Bryce Z Stewart
- From the Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria 3086
| | - Patrick O Humbert
- From the Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria 3086.,Cell Cycle and Cancer Genetics Laboratory, Research Division, Peter MacCallum Cancer Centre, and.,Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, Victoria 3002, and.,the Departments of Biochemistry and Molecular Biology.,Pathology, and
| | - Helena E Richardson
- From the Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria 3086.,Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, Victoria 3002, and.,the Cell Cycle and Development Laboratory.,the Departments of Biochemistry and Molecular Biology.,Anatomy and Neuroscience, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Marc Kvansakul
- From the Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria 3086,
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21
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Gan G, Zhang C. The precise subcellular localization of Dlg in the Drosophila larva body wall using improved pre-embedding immuno-EM. J Neurosci Res 2017; 96:467-480. [PMID: 29231975 DOI: 10.1002/jnr.24139] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2017] [Revised: 07/12/2017] [Accepted: 07/21/2017] [Indexed: 12/21/2022]
Abstract
Discs-large (Dlg) plays important roles in nerve tissue and epithelial tissue in Drosophila. However, the precise positioning of Dlg in the neuromuscular junction remains to be confirmed using an optimized labeling method. In this study, we improved the method of pre-embedding immunogold electron microscopy without the osmic tetroxide procedure, and we found that Lowicryl K4 M resin and low temperature helped to preserve the authenticity of the labeling signal with relatively good contrast. Dlg was strongly expressed in the entire subsynaptic reticulum (SSR) membrane of type Ib boutons, expressed in parts of the SSR membrane of type Is boutons, weakly expressed in axon terminals and axons, and not expressed in pre- or postsynaptic membranes of type Is boutons. In muscle cells and stratum corneum cells, Dlg was expressed both in the cytoplasm and in organelles with biomembranes. The precise location of Dlg in SSR membranes, rather than in postsynaptic membranes, shows that Dlg, with its multiple domains, acts as a remote or indirect regulator in postsynaptic signal transduction.
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Affiliation(s)
- Guangming Gan
- Medical School Southeast University, Nanjing, China.,Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Southeast University, Nanjing, China
| | - Chenchen Zhang
- Medical School Southeast University, Nanjing, China.,Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Southeast University, Nanjing, China
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22
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Golub O, Wee B, Newman RA, Paterson NM, Prehoda KE. Activation of Discs large by aPKC aligns the mitotic spindle to the polarity axis during asymmetric cell division. eLife 2017; 6. [PMID: 29185419 PMCID: PMC5706957 DOI: 10.7554/elife.32137] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Accepted: 11/21/2017] [Indexed: 12/14/2022] Open
Abstract
Asymmetric division generates cellular diversity by producing daughter cells with different fates. In animals, the mitotic spindle aligns with Par complex polarized fate determinants, ensuring that fate determinant cortical domains are bisected by the cleavage furrow. Here, we investigate the mechanisms that couple spindle orientation to polarity during asymmetric cell division of Drosophila neuroblasts. We find that the tumor suppressor Discs large (Dlg) links the Par complex component atypical Protein Kinase C (aPKC) to the essential spindle orientation factor GukHolder (GukH). Dlg is autoinhibited by an intramolecular interaction between its SH3 and GK domains, preventing Dlg interaction with GukH at cortical sites lacking aPKC. When co-localized with aPKC, Dlg is phosphorylated in its SH3 domain which disrupts autoinhibition and allows GukH recruitment by the GK domain. Our work establishes a molecular connection between the polarity and spindle orientation machineries during asymmetric cell division.
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Affiliation(s)
- Ognjen Golub
- Institute of Molecular Biology, Department of Chemistry and Biochemistry, University of Oregon, Eugene, United States
| | - Brett Wee
- Institute of Molecular Biology, Department of Chemistry and Biochemistry, University of Oregon, Eugene, United States
| | - Rhonda A Newman
- Institute of Molecular Biology, Department of Chemistry and Biochemistry, University of Oregon, Eugene, United States
| | - Nicole M Paterson
- Institute of Molecular Biology, Department of Chemistry and Biochemistry, University of Oregon, Eugene, United States
| | - Kenneth E Prehoda
- Institute of Molecular Biology, Department of Chemistry and Biochemistry, University of Oregon, Eugene, United States
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23
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Milgrom-Hoffman M, Humbert PO. Regulation of cellular and PCP signalling by the Scribble polarity module. Semin Cell Dev Biol 2017; 81:33-45. [PMID: 29154823 DOI: 10.1016/j.semcdb.2017.11.021] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2017] [Revised: 11/11/2017] [Accepted: 11/13/2017] [Indexed: 10/18/2022]
Abstract
Since the first identification of the Scribble polarity module proteins as a new class of tumour suppressors that regulate both cell polarity and proliferation, an increasing amount of evidence has uncovered a broader role for Scribble, Dlg and Lgl in the control of fundamental cellular functions and their signalling pathways. Here, we review these findings as well as discuss more specifically the role of the Scribble module in PCP signalling.
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Affiliation(s)
- Michal Milgrom-Hoffman
- Department of Biochemistry & Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria 3086, Australia
| | - Patrick O Humbert
- Department of Biochemistry & Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria 3086, Australia; Department of Biochemistry & Molecular Biology, University of Melbourne, Melbourne, Victoria 3010, Australia; Department of Pathology, University of Melbourne, Melbourne, Victoria 3010, Australia.
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24
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Wen W, Zhang M. Protein Complex Assemblies in Epithelial Cell Polarity and Asymmetric Cell Division. J Mol Biol 2017; 430:3504-3520. [PMID: 28963071 DOI: 10.1016/j.jmb.2017.09.013] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 09/16/2017] [Accepted: 09/19/2017] [Indexed: 12/24/2022]
Abstract
Asymmetric local concentration of protein complexes on distinct membrane regions is a fundamental property in numerous biological processes and is a hallmark of cell polarity. Evolutionarily conserved core polarity proteins form specific and dynamic networks to regulate the establishment and maintenance of cell polarity, as well as distinct polarity-driven cellular events. This review focuses on the molecular and structural basis governing regulated formation of several sets of core cell polarity regulatory complexes, as well as their functions in epithelial cell polarization and asymmetric cell division.
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Affiliation(s)
- Wenyu Wen
- Department of Neurosurgery, Huashan Hospital, Institutes of Biomedical Sciences, Fudan University, Shanghai 200040, China; Key Laboratory of Metabolism and Molecular Medicine, Ministry of Education, Department of Systems Biology for Medicine, School of Basic Medical Sciences, Shanghai Medical College, Fudan University, Shanghai 200032, PR China.
| | - Mingjie Zhang
- Division of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China; Center of Systems Biology and Human Health, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China.
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25
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Campanale JP, Sun TY, Montell DJ. Development and dynamics of cell polarity at a glance. J Cell Sci 2017; 130:1201-1207. [PMID: 28365593 DOI: 10.1242/jcs.188599] [Citation(s) in RCA: 118] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Cells exhibit morphological and molecular asymmetries that are broadly categorized as cell polarity. The cell polarity established in early embryos prefigures the macroscopic anatomical asymmetries characteristic of adult animals. For example, eggs and early embryos have polarized distributions of RNAs and proteins that generate global anterior/posterior and dorsal/ventral axes. The molecular programs that polarize embryos are subsequently reused in multiple contexts. Epithelial cells require apical/basal polarity to establish their barrier function. Migrating cells polarize in the direction of movement, creating distinct leading and trailing structures. Asymmetrically dividing stem cells partition different molecules between themselves and their daughter cells. Cell polarity can develop de novo, be maintained through rounds of cell division and be dynamically remodeled. In this Cell Science at a Glance review and poster, we describe molecular asymmetries that underlie cell polarity in several cellular contexts. We highlight multiple developmental systems that first establish cell/developmental polarity, and then maintain it. Our poster showcases repeated use of the Par, Scribble and Crumbs polarity complexes, which drive the development of cell polarity in many cell types and organisms. We then briefly discuss the diverse and dynamic changes in cell polarity that occur during cell migration, asymmetric cell division and in planar polarized tissues.
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Affiliation(s)
- Joseph P Campanale
- Department of Molecular, Cellular and Developmental Biology, University of California Santa Barbara, Santa Barbara, CA 93106, USA
| | - Thomas Y Sun
- Department of Molecular, Cellular and Developmental Biology, University of California Santa Barbara, Santa Barbara, CA 93106, USA
| | - Denise J Montell
- Department of Molecular, Cellular and Developmental Biology, University of California Santa Barbara, Santa Barbara, CA 93106, USA
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26
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Cervantes-Sandoval I, Chakraborty M, MacMullen C, Davis RL. Scribble Scaffolds a Signalosome for Active Forgetting. Neuron 2016; 90:1230-1242. [PMID: 27263975 DOI: 10.1016/j.neuron.2016.05.010] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Revised: 03/24/2016] [Accepted: 04/25/2016] [Indexed: 12/13/2022]
Abstract
Forgetting, one part of the brain's memory management system, provides balance to the encoding and consolidation of new information by removing unused or unwanted memories or by suppressing their expression. Recent studies identified the small G protein, Rac1, as a key player in the Drosophila mushroom bodies neurons (MBn) for active forgetting. We subsequently discovered that a few dopaminergic neurons (DAn) that innervate the MBn mediate forgetting. Here we show that Scribble, a scaffolding protein known primarily for its role as a cell polarity determinant, orchestrates the intracellular signaling for normal forgetting. Knocking down scribble expression in either MBn or DAn impairs normal memory loss. Scribble interacts physically and genetically with Rac1, Pak3, and Cofilin within MBn, nucleating a forgetting signalosome that is downstream of dopaminergic inputs that regulate forgetting. These results bind disparate molecular players in active forgetting into a single signaling pathway: Dopamine→ Dopamine Receptor→ Scribble→ Rac→ Cofilin.
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Affiliation(s)
| | - Molee Chakraborty
- Department of Neuroscience, The Scripps Research Institute Florida, Jupiter, FL 33458, USA
| | - Courtney MacMullen
- Department of Neuroscience, The Scripps Research Institute Florida, Jupiter, FL 33458, USA
| | - Ronald L Davis
- Department of Neuroscience, The Scripps Research Institute Florida, Jupiter, FL 33458, USA.
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27
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Lin WH, Asmann YW, Anastasiadis PZ. Expression of polarity genes in human cancer. Cancer Inform 2015; 14:15-28. [PMID: 25991909 PMCID: PMC4390136 DOI: 10.4137/cin.s18964] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Revised: 02/10/2015] [Accepted: 02/12/2015] [Indexed: 01/01/2023] Open
Abstract
Polarity protein complexes are crucial for epithelial apical–basal polarity and directed cell migration. Since alterations of these processes are common in cancer, polarity proteins have been proposed to function as tumor suppressors or oncogenic promoters. Here, we review the current understanding of polarity protein functions in epithelial homeostasis, as well as tumor formation and progression. As most previous studies focused on the function of single polarity proteins in simplified model systems, we used a genomics approach to systematically examine and identify the expression profiles of polarity genes in human cancer. The expression profiles of polarity genes were distinct in different human tissues and classified cancer types. Additionally, polarity expression profiles correlated with disease progression and aggressiveness, as well as with identified cancer types, where specific polarity genes were commonly altered. In the case of Scribble, gene expression analysis indicated its common amplification and upregulation in human cancer, suggesting a tumor promoting function.
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Affiliation(s)
- Wan-Hsin Lin
- Department of Cancer Biology, Mayo Clinic, Jacksonville, FL, USA
| | - Yan W Asmann
- Department of Health Sciences Research, Mayo Clinic, Jacksonville, FL, USA
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Garcia JD, Dewey EB, Johnston CA. Dishevelled binds the Discs large 'Hook' domain to activate GukHolder-dependent spindle positioning in Drosophila. PLoS One 2014; 9:e114235. [PMID: 25461409 PMCID: PMC4252473 DOI: 10.1371/journal.pone.0114235] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Accepted: 11/05/2014] [Indexed: 11/19/2022] Open
Abstract
Communication between cortical cell polarity cues and the mitotic spindle ensures proper orientation of cell divisions within complex tissues. Defects in mitotic spindle positioning have been linked to various developmental disorders and have recently emerged as a potential contributor to tumorigenesis. Despite the importance of this process to human health, the molecular mechanisms that regulate spindle orientation are not fully understood. Moreover, it remains unclear how diverse cortical polarity complexes might cooperate to influence spindle positioning. We and others have demonstrated spindle orientation roles for Dishevelled (Dsh), a key regulator of planar cell polarity, and Discs large (Dlg), a conserved apico-basal cell polarity regulator, effects which were previously thought to operate within distinct molecular pathways. Here we identify a novel direct interaction between the Dsh-PDZ domain and the alternatively spliced “I3-insert” of the Dlg-Hook domain, thus establishing a potential convergent Dsh/Dlg pathway. Furthermore, we identify a Dlg sequence motif necessary for the Dsh interaction that shares homology to the site of Dsh binding in the Frizzled receptor. Expression of Dsh enhanced Dlg-mediated spindle positioning similar to deletion of the Hook domain. This Dsh-mediated activation was dependent on the Dlg-binding partner, GukHolder (GukH). These results suggest that Dsh binding may regulate core interdomain conformational dynamics previously described for Dlg. Together, our results identify Dlg as an effector of Dsh signaling and demonstrate a Dsh-mediated mechanism for the activation of Dlg/GukH-dependent spindle positioning. Cooperation between these two evolutionarily-conserved cell polarity pathways could have important implications to both the development and maintenance of tissue homeostasis in animals.
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Affiliation(s)
- Joshua D. Garcia
- Department of Biology, University of New Mexico, Albuquerque, New Mexico, United States of America
| | - Evan B. Dewey
- Department of Biology, University of New Mexico, Albuquerque, New Mexico, United States of America
| | - Christopher A. Johnston
- Department of Biology, University of New Mexico, Albuquerque, New Mexico, United States of America
- * E-mail:
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29
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Ngok SP, Lin WH, Anastasiadis PZ. Establishment of epithelial polarity--GEF who's minding the GAP? J Cell Sci 2014; 127:3205-15. [PMID: 24994932 DOI: 10.1242/jcs.153197] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Cell polarization is a fundamental process that underlies epithelial morphogenesis, cell motility, cell division and organogenesis. Loss of polarity predisposes tissues to developmental disorders and contributes to cancer progression. The formation and establishment of epithelial cell polarity is mediated by the cooperation of polarity protein complexes, namely the Crumbs, partitioning defective (Par) and Scribble complexes, with Rho family GTPases, including RhoA, Rac1 and Cdc42. The activation of different GTPases triggers distinct downstream signaling pathways to modulate protein-protein interactions and cytoskeletal remodeling. The spatio-temporal activation and inactivation of these small GTPases is tightly controlled by a complex interconnected network of different regulatory proteins, including guanine-nucleotide-exchange factors (GEFs), GTPase-activating proteins (GAPs), and guanine-nucleotide-dissociation inhibitors (GDIs). In this Commentary, we focus on current understanding on how polarity complexes interact with GEFs and GAPs to control the precise location and activation of Rho GTPases (Crumbs for RhoA, Par for Rac1, and Scribble for Cdc42) to promote apical-basal polarization in mammalian epithelial cells. The mutual exclusion of GTPase activities, especially that of RhoA and Rac1, which is well established, provides a mechanism through which polarity complexes that act through distinct Rho GTPases function as cellular rheostats to fine-tune specific downstream pathways to differentiate and preserve the apical and basolateral domains. This article is part of a Minifocus on Establishing polarity.
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Affiliation(s)
- Siu P Ngok
- Department of Cancer Biology, Mayo Clinic Comprehensive Cancer Center, Griffin Cancer Research Building, Room 307, 4500 San Pablo Road, Jacksonville, FL 32224, USA
| | - Wan-Hsin Lin
- Department of Cancer Biology, Mayo Clinic Comprehensive Cancer Center, Griffin Cancer Research Building, Room 307, 4500 San Pablo Road, Jacksonville, FL 32224, USA
| | - Panos Z Anastasiadis
- Department of Cancer Biology, Mayo Clinic Comprehensive Cancer Center, Griffin Cancer Research Building, Room 307, 4500 San Pablo Road, Jacksonville, FL 32224, USA
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30
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Zhu J, Shang Y, Wan Q, Xia Y, Chen J, Du Q, Zhang M. Phosphorylation-dependent interaction between tumor suppressors Dlg and Lgl. Cell Res 2014; 24:451-63. [PMID: 24513855 DOI: 10.1038/cr.2014.16] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Revised: 11/27/2013] [Accepted: 01/13/2014] [Indexed: 02/08/2023] Open
Abstract
The tumor suppressors Discs Large (Dlg), Lethal giant larvae (Lgl) and Scribble are essential for the establishment and maintenance of epithelial cell polarity in metazoan. Dlg, Lgl and Scribble are known to interact strongly with each other genetically and form the evolutionarily conserved Scribble complex. Despite more than a decade of extensive research, it has not been demonstrated whether Dlg, Lgl and Scribble physically interact with each other. Here, we show that Dlg directly interacts with Lgl in a phosphorylation-dependent manner. Phosphorylation of any one of the three conserved Ser residues situated in the central linker region of Lgl is sufficient for its binding to the Dlg guanylate kinase (GK) domain. The crystal structures of the Dlg4 GK domain in complex with two phosphor-Lgl2 peptides reveal the molecular mechanism underlying the specific and phosphorylation-dependent Dlg/Lgl complex formation. In addition to providing a mechanistic basis underlying the regulated formation of the Scribble complex, the structure of the Dlg/Lgl complex may also serve as a starting point for designing specific Dlg inhibitors for targeting the Scribble complex formation.
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Affiliation(s)
- Jinwei Zhu
- Division of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Yuan Shang
- Division of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Qingwen Wan
- Department of Neurology, Institute of Molecular Medicine and Genetics, Medical College of Georgia, Georgia Regents University, Augusta, GA 30912, USA
| | - Yitian Xia
- Division of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Jia Chen
- 1] Division of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China [2] Current address: The Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, UK
| | - Quansheng Du
- Department of Neurology, Institute of Molecular Medicine and Genetics, Medical College of Georgia, Georgia Regents University, Augusta, GA 30912, USA
| | - Mingjie Zhang
- 1] Division of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China [2] Center of Systems Biology and Human Health, School of Science and Institute for Advanced Study, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
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31
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Staples J, Broadie K. The cell polarity scaffold Lethal Giant Larvae regulates synapse morphology and function. J Cell Sci 2013; 126:1992-2003. [PMID: 23444371 DOI: 10.1242/jcs.120139] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Lethal Giant Larvae (LGL) is a cytosolic cell polarity scaffold whose loss dominantly enhances neuromuscular junction (NMJ) synaptic overgrowth caused by loss of the Fragile X Mental Retardation Protein (FMRP). However, direct roles for LGL in NMJ morphological and functional development have not before been tested. Here, we use confocal imaging and two-electrode voltage-clamp electrophysiology at the Drosophila larval NMJ to define the synaptic requirements of LGL. We find that LGL is expressed both pre- and postsynaptically, where the scaffold localizes at the membrane on both sides of the synaptic interface. We show that LGL has a cell autonomous presynaptic role facilitating NMJ terminal branching and synaptic bouton formation. Moreover, loss of both pre- and postsynaptic LGL strongly decreases evoked neurotransmission strength, whereas the frequency and amplitude of spontaneous synaptic vesicle fusion events is increased. Cell-targeted RNAi and rescue reveals separable pre- and postsynaptic LGL roles mediating neurotransmission. We show that presynaptic LGL facilitates the assembly of active zone vesicle fusion sites, and that neuronally targeted rescue of LGL is sufficient to ameliorate increased synaptic vesicle cycling imaged with FM1-43 dye labeling. Postsynaptically, we show that loss of LGL results in a net increase in total glutamate receptor (GluR) expression, associated with the selective elevation of GluRIIB subunit-containing receptors. Taken together, these data indicate that the presynaptic LGL scaffold facilitates the assembly of active zone fusion sites to regulate synaptic vesicle cycling, and that the postsynaptic LGL scaffold modulates glutamate receptor composition and function.
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Affiliation(s)
- Jon Staples
- Department of Biological Sciences, Kennedy Center for Research on Human Development, Vanderbilt University, Nashville, TN 37212, USA
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Polarity protein complex Scribble/Lgl/Dlg and epithelial cell barriers. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2013; 763:149-70. [PMID: 23397623 DOI: 10.1007/978-1-4614-4711-5_7] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The Scribble polarity complex or module is one of the three polarity modules that regulate cell polarity in multiple epithelia including blood-tissue barriers. This protein complex is composed of Scribble, Lethal giant larvae (Lgl) and Discs large (Dlg), which are well conserved across species from fruitflies and worms to mammals. Originally identified in Drosophila and C. elegans where the Scribble complex was found to work with the Par-based and Crumbs-based polarity modules to regulate apicobasal polarity and asymmetry in cells and tissues during embryogenesis, their mammalian homologs have all been identified in recent years. Components of the Scribble complex are known to regulate multiple cellular functions besides cell polarity, which include cell proliferation, assembly and maintenance of adherens junction (AJ) and tight junction (TJ), and they are also tumor suppressors. Herein, we provide an update on the Scribble polarity complex and how this protein complex modulates cell adhesion with some emphasis on its role in Sertoli cell blood-testis barrier (BTB) function. It should be noted that this is a rapidly developing field, in particular the role of this protein module in blood-tissue barriers, and this short chapter attempts to provide the information necessary for investigators studying reproductive biology and blood-tissue barriers to design future studies. We also include results of recent studies from flies and worms since this information will be helpful in planning experiments for future functional studies in the testis to understand how Scribble-based proteins regulate BTB dynamics and spermatogenesis.
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33
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The Scribble-Dlg-Lgl polarity module in development and cancer: from flies to man. Essays Biochem 2012; 53:141-68. [PMID: 22928514 DOI: 10.1042/bse0530141] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The Scribble, Par and Crumbs modules were originally identified in the vinegar (fruit) fly, Drosophila melanogaster, as being critical regulators of apico-basal cell polarity. In the present chapter we focus on the Scribble polarity module, composed of Scribble, discs large and lethal giant larvae. Since the discovery of the role of the Scribble polarity module in apico-basal cell polarity, these proteins have also been recognized as having important roles in other forms of polarity, as well as regulation of the actin cytoskeleton, cell signalling and vesicular trafficking. In addition to these physiological roles, an important role for polarity proteins in cancer progression has also been uncovered, with loss of polarity and tissue architecture being strongly correlated with metastatic disease.
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Verghese S, Waghmare I, Kwon H, Hanes K, Kango-Singh M. Scribble acts in the Drosophila fat-hippo pathway to regulate warts activity. PLoS One 2012; 7:e47173. [PMID: 23144804 PMCID: PMC3489842 DOI: 10.1371/journal.pone.0047173] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2012] [Accepted: 09/10/2012] [Indexed: 01/15/2023] Open
Abstract
Epithelial cells are the major cell-type for all organs in multicellular organisms. In order to achieve correct organ size, epithelial tissues need mechanisms that limit their proliferation, and protect tissues from damage caused by defective epithelial cells. Recently, the Hippo signaling pathway has emerged as a major mechanism that orchestrates epithelial development. Hippo signaling is required for cells to stop proliferation as in the absence of Hippo signaling tissues continue to proliferate and produce overgrown organs or tumors. Studies in Drosophila have led the way in providing a framework for how Hippo alters the pattern of gene transcription in target cells, leading to changes in cell proliferation, survival, and other behaviors. Scribble (Scrib) belongs to a class of neoplastic tumor suppressor genes that are required to establish apical-basal cell polarity. The disruption of apical-basal polarity leads to uncontrolled cell proliferation of epithelial cells. The interaction of apical basal polarity genes with the Hippo pathway has been an area of intense investigation. Loss of scrib has been known to affect Hippo pathway targets, however, its functions in the Hippo pathway still remain largely unknown. We investigated the interactions of Scrib with the Hippo pathway. We present data suggesting that Drosophila scrib acts downstream of the Fat (Ft) receptor, and requires Hippo signaling for its growth regulatory functions. We show that Ft requires Scrib to interact with Expanded (Ex) and Dachs (D), and for regulating Warts (Wts) levels and stability, thus placing Scrib in the Hippo pathway network.
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Affiliation(s)
- Shilpi Verghese
- Department of Biology, University of Dayton, Dayton, Ohio, United States of America
| | - Indrayani Waghmare
- Department of Biology, University of Dayton, Dayton, Ohio, United States of America
| | - Hailey Kwon
- Department of Biology, University of Dayton, Dayton, Ohio, United States of America
| | - Katelin Hanes
- Department of Biology, University of Dayton, Dayton, Ohio, United States of America
| | - Madhuri Kango-Singh
- Department of Biology, University of Dayton, Dayton, Ohio, United States of America
- Pre-Medical Programs, University of Dayton, Dayton, Ohio, United States of America
- Center for Tissue Regeneration and Engineering at Dayton, University of Dayton, Dayton, Ohio, United States of America
- * E-mail:
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35
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Melnattur KV, Berdnik D, Rusan Z, Ferreira CJ, Nambu JR. The sox gene Dichaete is expressed in local interneurons and functions in development of the Drosophila adult olfactory circuit. Dev Neurobiol 2012; 73:107-26. [PMID: 22648855 DOI: 10.1002/dneu.22038] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2011] [Accepted: 05/16/2012] [Indexed: 11/07/2022]
Abstract
In insects, the primary sites of integration for olfactory sensory input are the glomeruli in the antennal lobes. Here, axons of olfactory receptor neurons synapse with dendrites of the projection neurons that relay olfactory input to higher brain centers, such as the mushroom bodies and lateral horn. Interactions between olfactory receptor neurons and projection neurons are modulated by excitatory and inhibitory input from a group of local interneurons. While significant insight has been gleaned into the differentiation of olfactory receptor and projection neurons, much less is known about the development and function of the local interneurons. We have found that Dichaete, a conserved Sox HMG box gene, is strongly expressed in a cluster of LAAL cells located adjacent to each antennal lobe in the adult brain. Within these clusters, Dichaete protein expression is detected in both cholinergic and GABAergic local interneurons. In contrast, Dichaete expression is not detected in mature or developing projection neurons, or developing olfactory receptor neurons. Analysis of novel viable Dichaete mutant alleles revealed misrouting of specific projection neuron dendrites and axons, and alterations in glomeruli organization. These results suggest noncell autonomous functions of Dichaete in projection neuron differentiation as well as a potential role for Dichaete-expressing local interneurons in development of the adult olfactory circuitry.
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Affiliation(s)
- Krishna V Melnattur
- Biology Department, University of Massachusetts, Amherst, Massachusetts 01003, USA
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36
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Abstract
Cell polarization is an evolutionarily conserved process that facilitates asymmetric distribution of organelles and proteins and that is modified dynamically during physiological processes such as cell division, migration, and morphogenesis. The plasticity with which cells change their behavior and phenotype in response to cell intrinsic and extrinsic cues is an essential feature of normal physiology. In disease states such as cancer, cells lose their ability to behave normally in response to physiological cues. A molecular understanding of mechanisms that alter the behavior of cancer cells is limited. Cell polarity proteins are a recognized class of molecules that can receive and interpret both intrinsic and extrinsic signals to modulate cell behavior. In this review, we discuss how cell polarity proteins regulate a diverse array of biological processes and how they can contribute to alterations in the behavior of cancer cells.
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Affiliation(s)
- Senthil K Muthuswamy
- Ontario Cancer Institute, Campbell Family Institute for Breast Cancer Research, University of Toronto, Toronto M5G 2M9, Canada.
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37
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Abstract
Wnt proteins are best known for their profound roles in cell patterning, because they are required for the embryonic development of all animal species studied to date. Besides regulating cell fate, Wnt proteins are gaining increasing recognition for their roles in nervous system development and function. New studies indicate that multiple positive and negative Wnt signaling pathways take place simultaneously during the formation of vertebrate and invertebrate neuromuscular junctions. Although some Wnts are essential for the formation of NMJs, others appear to play a more modulatory role as part of multiple signaling pathways. Here we review the most recent findings regarding the function of Wnts at the NMJ from both vertebrate and invertebrate model systems.
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Affiliation(s)
- Kate Koles
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, 01605, USA
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38
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Johnston CA, Doe CQ, Prehoda KE. Structure of an enzyme-derived phosphoprotein recognition domain. PLoS One 2012; 7:e36014. [PMID: 22545154 PMCID: PMC3335814 DOI: 10.1371/journal.pone.0036014] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2012] [Accepted: 03/26/2012] [Indexed: 01/19/2023] Open
Abstract
Membrane Associated Guanylate Kinases (MAGUKs) contain a protein interaction domain (GKdom) derived from the enzyme Guanylate Kinase (GKenz). Here we show that GKdom from the MAGUK Discs large (Dlg) is a phosphoprotein recognition domain, specifically recognizing the phosphorylated form of the mitotic spindle orientation protein Partner of Inscuteable (Pins). We determined the structure of the Dlg-Pins complex to understand the dramatic transition from nucleotide kinase to phosphoprotein recognition domain. The structure reveals that the region of the GKdom that once served as the GMP binding domain (GBD) has been co-opted for protein interaction. Pins makes significantly more contact with the GBD than does GMP, but primarily with residues that are conserved between enzyme and domain revealing the versatility of the GBD as a platform for nucleotide and protein interactions. Mutational analysis reveals that the GBD is also used to bind the GK ligand MAP1a, suggesting that this is a common mode of MAGUK complex assembly. The GKenz undergoes a dramatic closing reaction upon GMP binding but the protein-bound GKdom remains in the ‘open’ conformation indicating that the dramatic conformational change has been lost in the conversion from nucleotide kinase to phosphoprotein recognition domain.
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Affiliation(s)
- Christopher A. Johnston
- Institute of Molecular Biology, University of Oregon, Eugene, Oregon, United States of America
- Institute of Neuroscience and Howard Hughes Medical Institute, University of Oregon, Eugene, Oregon, United States of America
| | - Chris Q. Doe
- Institute of Molecular Biology, University of Oregon, Eugene, Oregon, United States of America
- Institute of Neuroscience and Howard Hughes Medical Institute, University of Oregon, Eugene, Oregon, United States of America
| | - Kenneth E. Prehoda
- Institute of Molecular Biology, University of Oregon, Eugene, Oregon, United States of America
- * E-mail:
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39
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Oliva C, Escobedo P, Astorga C, Molina C, Sierralta J. Role of the MAGUK protein family in synapse formation and function. Dev Neurobiol 2012; 72:57-72. [PMID: 21739617 DOI: 10.1002/dneu.20949] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Synaptic function is crucially dependent on the spatial organization of the presynaptic and postsynaptic apparatuses and the juxtaposition of both membrane compartments. This precise arrangement is achieved by a protein network at the submembrane region of each cell that is built around scaffold proteins. The membrane-associated guanylate kinase (MAGUK) family of proteins is a widely expressed and well-conserved group of proteins that plays an essential role in the formation and regulation of this scaffolding. Here, we review general features of this protein family, focusing on the discs large and calcium/calmodulin-dependent serine protein kinase subfamilies of MAGUKs in the formation, function, and plasticity of synapses.
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Affiliation(s)
- Carlos Oliva
- Program of Physiology and Biophysics, Institute of Biomedical Sciences and Biomedical Neuroscience Institute, Faculty of Medicine, Universidad de Chile, Santiago 8380453, Chile
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40
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Broadie K, Baumgartner S, Prokop A. Extracellular matrix and its receptors in Drosophila neural development. Dev Neurobiol 2011; 71:1102-30. [PMID: 21688401 PMCID: PMC3192297 DOI: 10.1002/dneu.20935] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Extracellular matrix (ECM) and matrix receptors are intimately involved in most biological processes. The ECM plays fundamental developmental and physiological roles in health and disease, including processes underlying the development, maintenance, and regeneration of the nervous system. To understand the principles of ECM-mediated functions in the nervous system, genetic model organisms like Drosophila provide simple, malleable, and powerful experimental platforms. This article provides an overview of ECM proteins and receptors in Drosophila. It then focuses on their roles during three progressive phases of neural development: (1) neural progenitor proliferation, (2) axonal growth and pathfinding, and (3) synapse formation and function. Each section highlights known ECM and ECM-receptor components and recent studies done in mutant conditions to reveal their in vivo functions, all illustrating the enormous opportunities provided when merging work on the nervous system with systematic research into ECM-related gene functions.
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Affiliation(s)
- Kendal Broadie
- Departments of Biological Sciences and Cell and Developmental Biology, Kennedy Center for Research on Human Development, Vanderbilt University, Nashville, TN 37232 USA
| | - Stefan Baumgartner
- Department of Experimental Medical Sciences, Lund University, BMC B12, 22184 Lund, Sweden
| | - Andreas Prokop
- Faculty of Life Sciences, Wellcome Trust Centre for Cell-Matrix Research, Michael Smith Building, Oxford Road, Manchester M13 9PT, UK
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41
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Conversion of the enzyme guanylate kinase into a mitotic-spindle orienting protein by a single mutation that inhibits GMP-induced closing. Proc Natl Acad Sci U S A 2011; 108:E973-8. [PMID: 21990344 DOI: 10.1073/pnas.1104365108] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
New protein functions can require complex sequence changes, but the minimal path is not well understood. The guanylate kinase enzyme (GK(enz)), which catalyzes phosphotransfer from ATP to GMP, evolved into the GK domain (GK(dom)), a protein-binding domain found in membrane associate guanylate kinases that function in mitotic spindle orientation and cell adhesion. Using an induced polarity assay for GK(dom) function, we show that a single serine to proline mutation is sufficient to switch extant GK(enz) into a functional GK(dom). The mutation blocks catalysis (GK(enz) function) but allows protein binding and spindle orientation (GK(dom) function). Furthermore, whereas the GK(enz) undergoes a large closing motion upon GMP binding, fluorescence quenching and NMR demonstrate that the S → P mutation inhibits GMP-induced GK movements. Disrupting GK closing with a mutation at a different position also leads to GK(dom) function, suggesting that blocking the GK(enz) closing motion is sufficient for functional conversion of GK(enz) to GK(dom). Although subtle changes in protein function can require complex sequence paths, our work shows that entirely new functions can arise from single mutations that alter protein dynamics.
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42
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Walsh GS, Grant PK, Morgan JA, Moens CB. Planar polarity pathway and Nance-Horan syndrome-like 1b have essential cell-autonomous functions in neuronal migration. Development 2011; 138:3033-42. [PMID: 21693519 PMCID: PMC3119310 DOI: 10.1242/dev.063842] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Components of the planar cell polarity (PCP) pathway are required for the caudal tangential migration of facial branchiomotor (FBM) neurons, but how PCP signaling regulates this migration is not understood. In a forward genetic screen, we identified a new gene, nhsl1b, required for FBM neuron migration. nhsl1b encodes a WAVE-homology domain-containing protein related to human Nance-Horan syndrome (NHS) protein and Drosophila GUK-holder (Gukh), which have been shown to interact with components of the WAVE regulatory complex that controls cytoskeletal dynamics and with the polarity protein Scribble, respectively. Nhsl1b localizes to FBM neuron membrane protrusions and interacts physically and genetically with Scrib to control FBM neuron migration. Using chimeric analysis, we show that FBM neurons have two modes of migration: one involving interactions between the neurons and their planar-polarized environment, and an alternative, collective mode involving interactions between the neurons themselves. We demonstrate that the first mode of migration requires the cell-autonomous functions of Nhsl1b and the PCP components Scrib and Vangl2 in addition to the non-autonomous functions of Scrib and Vangl2, which serve to polarize the epithelial cells in the environment of the migrating neurons. These results define a role for Nhsl1b as a neuronal effector of PCP signaling and indicate that proper FBM neuron migration is directly controlled by PCP signaling between the epithelium and the migrating neurons.
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Affiliation(s)
- Gregory S Walsh
- Howard Hughes Medical Institute and Division of Basic Science, Fred Hutchinson Cancer Research Center, 1100 Fairview Avenue North, Seattle, WA 98109, USA
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43
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Abstract
The correct establishment and maintenance of cell polarity are crucial for normal cell physiology and tissue homeostasis. Conversely, loss of cell polarity, tissue disorganisation and excessive cell growth are hallmarks of cancer. In this review, we focus on identifying the stages of tumoural development that are affected by the loss or deregulation of epithelial cell polarity. Asymmetric division has recently emerged as a major regulatory mechanism that controls stem cell numbers and differentiation. Links between cell polarity and asymmetric cell division in the context of cancer will be examined. Apical–basal polarity and cell–cell adhesion are tightly interconnected. Hence, how loss of cell polarity in epithelial cells may promote epithelial mesenchymal transition and metastasis will also be discussed. Altogether, we present the argument that loss of epithelial cell polarity may have an important role in both the initiation of tumourigenesis and in later stages of tumour development, favouring the progression of tumours from benign to malignancy.
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Miranda-Laferte E, Gonzalez-Gutierrez G, Schmidt S, Zeug A, Ponimaskin EG, Neely A, Hidalgo P. Homodimerization of the Src homology 3 domain of the calcium channel β-subunit drives dynamin-dependent endocytosis. J Biol Chem 2011; 286:22203-10. [PMID: 21502319 DOI: 10.1074/jbc.m110.201871] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Voltage-dependent calcium channels constitute the main entry pathway for calcium into excitable cells. They are heteromultimers formed by an α(1) pore-forming subunit (Ca(V)α(1)) and accessory subunits. To achieve a precise coordination of calcium signals, the expression and activity of these channels is tightly controlled. The accessory β-subunit (Ca(V)β), a membrane associated guanylate kinase containing one guanylate kinase (β-GK) and one Src homology 3 (β-SH3) domain, has antagonistic effects on calcium currents by regulating different aspects of channel function. Although β-GK binds to a conserved site within the α(1)-pore-forming subunit and facilitates channel opening, β-SH3 binds to dynamin and promotes endocytosis. Here, we investigated the molecular switch underlying the functional duality of this modular protein. We show that β-SH3 homodimerizes through a single disulfide bond. Substitution of the only cysteine residue abolishes dimerization and impairs internalization of L-type Ca(V)1.2 channels expressed in Xenopus oocytes while preserving dynamin binding. Covalent linkage of the β-SH3 dimerization-deficient mutant yields a concatamer that binds to dynamin and restores endocytosis. Moreover, using FRET analysis, we show in living cells that Ca(V)β form oligomers and that this interaction is reduced by Ca(V)α(1). Association of Ca(V)β with a polypeptide encoding the binding motif in Ca(V)α(1) inhibited endocytosis. Together, these findings reveal that β-SH3 dimerization is crucial for endocytosis and suggest that channel activation and internalization are two mutually exclusive functions of Ca(V)β. We propose that a change in the oligomeric state of Ca(V)β is the functional switch between channel activator and channel internalizer.
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Affiliation(s)
- Erick Miranda-Laferte
- Institut für Neurophysiologie, Medizinische Hochschule Hannover, 30625 Hannover, Germany
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Tervonen TA, Partanen JI, Saarikoski ST, Myllynen M, Marques E, Paasonen K, Moilanen A, Wohlfahrt G, Kovanen PE, Klefstrom J. Faulty epithelial polarity genes and cancer. Adv Cancer Res 2011; 111:97-161. [PMID: 21704831 DOI: 10.1016/b978-0-12-385524-4.00003-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Epithelial architecture is formed in tissues and organs when groups of epithelial cells are organized into polarized structures. The epithelial function and integrity as well as signaling across the epithelial layer is orchestrated by apical junctional complexes (AJCs), which are landmarks for PAR/CRUMBS and lateral SCRIB polarity modules and by dynamic interactions of the cells with underlying basement membrane (BM). These highly organized epithelial architectures are demolished in cancer. In all advanced epithelial cancers, malignant cells have lost polarity and connections to the basement membrane and they have become proliferative, motile, and invasive. Clearly, loss of epithelial integrity associates with tumor progression but does it contribute to tumor development? Evidence from studies in Drosophila and recently also in vertebrate models have suggested that even the oncogene-driven enforced cell proliferation can be conditional, dependant on the influence of cell-cell or cell-microenvironment contacts. Therefore, loss of epithelial integrity may not only be an obligate consequence of unscheduled proliferation of malignant cells but instead, malignant epithelial cells may need to acquire capacity to break free from the constraints of integrity to freely and autonomously proliferate. We discuss how epithelial polarity complexes form and regulate epithelial integrity, highlighting the roles of enzymes Rho GTPases, aPKCs, PI3K, and type II transmembrane serine proteases (TTSPs). We also discuss relevance of these pathways to cancer in light of genetic alterations found in human cancers and review molecular pathways and potential pharmacological strategies to revert or selectively eradicate disorganized tumor epithelium.
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LaJeunesse DR, Johnson B, Presnell JS, Catignas KK, Zapotoczny G. Peristalsis in the junction region of the Drosophila larval midgut is modulated by DH31 expressing enteroendocrine cells. BMC PHYSIOLOGY 2010; 10:14. [PMID: 20698983 PMCID: PMC2933646 DOI: 10.1186/1472-6793-10-14] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/24/2010] [Accepted: 08/10/2010] [Indexed: 11/24/2022]
Abstract
Background The underlying cellular and molecular mechanisms that coordinate the physiological processes in digestion are complex, cryptic, and involve the integration of multiple cellular and organ systems. In all intestines, peristaltic action of the gut moves food through the various stages of digestion from the anterior end towards the posterior, with the rate of flow dependent on signals, both intrinsic and extrinsic to the gut itself. Results We have identified an enteroendocrine cell type that regulates gut motility in the Drosophila melanogaster larval midgut. These cells are located at the junction of the anterior and the acidic portions of the midgut and are a group of enteroendocrine cells that express the peptide hormone Diuretic Hormone 31 in this region of the gut. Using cell ablation and ectopic activation via expression of the Chlamydomonas reinhardtii blue light-activated channelopsin, we demonstrate that these enteroendocrine cells are both necessary and sufficient for the peristalsis in the junction region of the midgut and require the Diuretic Hormone 31 to affect normal peristalsis in this region. Within the same junction region of the midgut, we have also identified morphological features suggesting that this region acts as a valve that regulates the transit of food from the anterior midgut into the acidic portion of the gut. Conclusions We have characterized and described a set of enteroendocrine cells called the Midgut Junction DH31 expressing cells that are required for peristaltic movement in the junction region between the anterior portion and acidic region of the larval midgut of Drosophila melanogaster. We have shown that the Midgut Junction DH31 expressing cells are necessary and sufficient for motility and that the peptide hormone DH31 is required for peristalsis in the junction region of the midgut. The Drosophila model system will allow for a further dissection of the digestion process and provide a better understanding of the mechanisms that regulate digestion in all organisms.
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Affiliation(s)
- Dennis R LaJeunesse
- Department of Biology, 312 Eberhart Bldg,, University of North Carolina Greensboro, Greensboro, North Carolina 27402, USA.
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Thomas U, Kobler O, Gundelfinger ED. TheDrosophilaLarval Neuromuscular Junction as a Model for Scaffold Complexes at Glutamatergic Synapses: Benefits and Limitations. J Neurogenet 2010; 24:109-19. [DOI: 10.3109/01677063.2010.493589] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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A perisynaptic ménage à trois between Dlg, DLin-7, and Metro controls proper organization of Drosophila synaptic junctions. J Neurosci 2010; 30:5811-24. [PMID: 20427642 DOI: 10.1523/jneurosci.0778-10.2010] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Structural plasticity of synaptic junctions is a prerequisite to achieve and modulate connectivity within nervous systems, e.g., during learning and memory formation. It demands adequate backup systems that allow remodeling while retaining sufficient stability to prevent unwanted synaptic disintegration. The strength of submembranous scaffold complexes, which are fundamental to the architecture of synaptic junctions, likely constitutes a crucial determinant of synaptic stability. Postsynaptic density protein-95 (PSD-95)/ Discs-large (Dlg)-like membrane-associated guanylate kinases (DLG-MAGUKs) are principal scaffold proteins at both vertebrate and invertebrate synapses. At Drosophila larval glutamatergic neuromuscular junctions (NMJs) DlgA and DlgS97 exert pleiotropic functions, probably reflecting a few known and a number of yet-unknown binding partners. In this study we have identified Metro, a novel p55/MPP-like Drosophila MAGUK as a major binding partner of perisynaptic DlgS97 at larval NMJs. Based on homotypic LIN-2,-7 (L27) domain interactions, Metro stabilizes junctional DlgS97 in a complex with the highly conserved adaptor protein DLin-7. In a remarkably interdependent manner, Metro and DLin-7 act downstream of DlgS97 to control NMJ expansion and proper establishment of synaptic boutons. Using quantitative 3D-imaging we further demonstrate that the complex controls the size of postsynaptic glutamate receptor fields. Our findings accentuate the importance of perisynaptic scaffold complexes for synaptic stabilization and organization.
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Sun Y, Aiga M, Yoshida E, Humbert PO, Bamji SX. Scribble interacts with beta-catenin to localize synaptic vesicles to synapses. Mol Biol Cell 2009; 20:3390-400. [PMID: 19458197 DOI: 10.1091/mbc.e08-12-1172] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
An understanding of how synaptic vesicles are recruited to and maintained at presynaptic compartments is required to discern the molecular mechanisms underlying presynaptic assembly and plasticity. We have previously demonstrated that cadherin-beta-catenin complexes cluster synaptic vesicles at presynaptic sites. Here we show that scribble interacts with the cadherin-beta-catenin complex to coordinate vesicle localization. Scribble and beta-catenin are colocalized at synapses and can be coimmunoprecipitated from neuronal lysates, indicating an interaction between scribble and beta-catenin at the synapse. Using an RNA interference approach, we demonstrate that scribble is important for the clustering of synaptic vesicles at synapses. Indeed, in scribble knockdown cells, there is a diffuse distribution of synaptic vesicles along the axon, and a deficit in vesicle recycling. Despite this, synapse number and the distribution of the presynaptic active zone protein, bassoon, remain unchanged. These effects largely phenocopy those observed after ablation of beta-catenin. In addition, we show that loss of beta-catenin disrupts scribble localization in primary neurons but that the localization of beta-catenin is not dependent on scribble. Our data supports a model by which scribble functions downstream of beta-catenin to cluster synaptic vesicles at developing synapses.
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Affiliation(s)
- Yu Sun
- Department of Cellular and Physiological Sciences and the Brain Research Centre, University of British Columbia, Vancouver, BC, V6T-1Z3, Canada
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Newman RA, Prehoda KE. Intramolecular interactions between the SRC homology 3 and guanylate kinase domains of discs large regulate its function in asymmetric cell division. J Biol Chem 2009; 284:12924-32. [PMID: 19261607 DOI: 10.1074/jbc.m809304200] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Membrane-associated guanylate kinases (MAGUKs) regulate the formation and function of molecular assemblies at specialized regions of the membrane. Allosteric regulation of an intramolecular interaction between the Src homology 3 (SH3) and guanylate kinase (GK) domains of MAGUKs is thought to play a central role in regulating MAGUK function. Here we show that a mutant of the Drosophila MAGUK Discs large (Dlg), dlg(sw), encodes a form of Dlg that disrupts the intramolecular association while leaving the SH3 and GK domains intact, providing an excellent model system to assess the role of the SH3-GK intramolecular interaction in MAGUK function. Analysis of asymmetric cell division of maternal-zygotic dlg(sw) embryonic neuroblasts demonstrates that the intramolecular interaction is not required for Dlg localization but is necessary for cell fate determinant segregation to the basal cortex and mitotic spindle alignment with the cortical polarity axis. These defects ultimately result in improper patterning of the embryonic central nervous system. Furthermore, we demonstrate that the sw mutation of Dlg results in unregulated complex assembly as assessed by GukHolder association with the SH3-GK versus PDZ-SH3-GK modules of Dlg(sw). From these studies, we conclude that allosteric regulation of the SH3-GK intramolecular interaction is required for regulation of MAGUK function in asymmetric cell division, possibly through regulation of complex assembly.
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Affiliation(s)
- Rhonda A Newman
- Department of Chemistry and Institute of Molecular Biology, University of Oregon, Eugene, OR 97403, USA
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