1
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Burcklé C, Raitière J, Michaux G, Kodjabachian L, Le Bivic A. Crb3 is required to organize the apical domain of multiciliated cells. J Cell Sci 2024; 137:jcs261046. [PMID: 37840525 DOI: 10.1242/jcs.261046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Accepted: 10/10/2023] [Indexed: 10/17/2023] Open
Abstract
Cell shape changes mainly rely on the remodeling of the actin cytoskeleton. Multiciliated cells (MCCs) of the mucociliary epidermis of Xenopus laevis embryos, as they mature, dramatically reshape their apical domain to grow cilia, in coordination with the underlying actin cytoskeleton. Crumbs (Crb) proteins are multifaceted transmembrane apical polarity proteins known to recruit actin linkers and promote apical membrane growth. Here, we identify the homeolog Crb3.L as an important player for the migration of centrioles or basal bodies (collectively centrioles/BBs) and apical domain morphogenesis in MCCs. Crb3.L is present in cytoplasmic vesicles close to the ascending centrioles/BBs, where it partially colocalizes with Rab11a. Crb3.L morpholino-mediated depletion in MCCs caused abnormal migration of centrioles/BBs, a reduction of their apical surface, disorganization of their apical actin meshwork and defective ciliogenesis. Rab11a morpholino-mediated depletion phenocopied Crb3.L loss-of-function in MCCs. Thus, the control of centrioles/BBs migration by Crb3.L might be mediated by Rab11a-dependent apical trafficking. Furthermore, we show that both phospho-activated ERM (pERM; Ezrin-Radixin-Moesin) and Crb3.L are recruited to the growing apical domain of MCCs, where Crb3.L likely anchors pERM, allowing actin-dependent expansion of the apical membrane.
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Affiliation(s)
- Céline Burcklé
- Aix-Marseille University, CNRS, UMR 7288, Developmental Biology Institute of Marseille (IBDM), Marseille, F-13288 France
| | - Juliette Raitière
- Aix-Marseille University, CNRS, UMR 7288, Developmental Biology Institute of Marseille (IBDM), Marseille, F-13288 France
| | - Grégoire Michaux
- Univ Rennes, CNRS, IGDR (Institut de Génétique et Développement de Rennes), UMR 6290, F-35000 Rennes, France
| | - Laurent Kodjabachian
- Aix Marseille University, CNRS, UMR 7288, Developmental Biology Institute of Marseille (IBDM), Turing Centre for Living Systems, Marseille, F-13288 France
| | - André Le Bivic
- Aix-Marseille University, CNRS, UMR 7288, Developmental Biology Institute of Marseille (IBDM), Marseille, F-13288 France
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2
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Esmangart de Bournonville T, Jaglarz MK, Durel E, Le Borgne R. ESCRT-III-dependent adhesive and mechanical changes are triggered by a mechanism detecting alteration of septate junction integrity in Drosophila epithelial cells. eLife 2024; 13:e91246. [PMID: 38305711 PMCID: PMC10959524 DOI: 10.7554/elife.91246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Accepted: 02/01/2024] [Indexed: 02/03/2024] Open
Abstract
Barrier functions of proliferative epithelia are constantly challenged by mechanical and chemical constraints. How epithelia respond to and cope with disturbances of barrier functions to allow tissue integrity maintenance is poorly characterised. Cellular junctions play an important role in this process and intracellular traffic contribute to their homeostasis. Here, we reveal that, in Drosophila pupal notum, alteration of the bi- or tricellular septate junctions (SJs) triggers a mechanism with two prominent outcomes. On one hand, there is an increase in the levels of E-cadherin, F-actin, and non-muscle myosin II in the plane of adherens junctions. On the other hand, β-integrin/Vinculin-positive cell contacts are reinforced along the lateral and basal membranes. We found that the weakening of SJ integrity, caused by the depletion of bi- or tricellular SJ components, alters ESCRT-III/Vps32/Shrub distribution, reduces degradation and instead favours recycling of SJ components, an effect that extends to other recycled transmembrane protein cargoes including Crumbs, its effector β-Heavy Spectrin Karst, and β-integrin. We propose a mechanism by which epithelial cells, upon sensing alterations of the SJ, reroute the function of Shrub to adjust the balance of degradation/recycling of junctional cargoes and thereby compensate for barrier junction defects to maintain epithelial integrity.
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Affiliation(s)
- Thomas Esmangart de Bournonville
- Univ Rennes, CNRS, IGDR (Institut de Génétique et Développement de Rennes) – UMR 6290RennesFrance
- Global Health Institute, School of Life Science, Ecole Polytechnique Fédérale de Lausanne (EPFL)LausanneSwitzerland
| | - Mariusz K Jaglarz
- Department of Developmental Biology and Invertebrate Morphology, Institute of Zoology and Biomedical Research, Jagiellonian University in KrakowKrakowPoland
| | - Emeline Durel
- Univ Rennes, CNRS, IGDR (Institut de Génétique et Développement de Rennes) – UMR 6290RennesFrance
| | - Roland Le Borgne
- Univ Rennes, CNRS, IGDR (Institut de Génétique et Développement de Rennes) – UMR 6290RennesFrance
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3
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Hong Y, Walling BL, Kim HR, Serratelli WS, Lozada JR, Sailer CJ, Amitrano AM, Lim K, Mongre RK, Kim KD, Capece T, Lomakina EB, Reilly NS, Vo K, Gerber SA, Fan TC, Yu ALT, Oakes PW, Waugh RE, Jun CD, Reagan PM, Kim M. ST3GAL1 and βII-spectrin pathways control CAR T cell migration to target tumors. Nat Immunol 2023; 24:1007-1019. [PMID: 37069398 PMCID: PMC10515092 DOI: 10.1038/s41590-023-01498-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Accepted: 03/21/2023] [Indexed: 04/19/2023]
Abstract
Adoptive transfer of genetically engineered chimeric antigen receptor (CAR) T cells is becoming a promising treatment option for hematological malignancies. However, T cell immunotherapies have mostly failed in individuals with solid tumors. Here, with a CRISPR-Cas9 pooled library, we performed an in vivo targeted loss-of-function screen and identified ST3 β-galactoside α-2,3-sialyltransferase 1 (ST3GAL1) as a negative regulator of the cancer-specific migration of CAR T cells. Analysis of glycosylated proteins revealed that CD18 is a major effector of ST3GAL1 in activated CD8+ T cells. ST3GAL1-mediated glycosylation induces the spontaneous nonspecific tissue sequestration of T cells by altering lymphocyte function-associated antigen-1 (LFA-1) endocytic recycling. Engineered CAR T cells with enhanced expression of βII-spectrin, a central LFA-1-associated cytoskeleton molecule, reversed ST3GAL1-mediated nonspecific T cell migration and reduced tumor growth in mice by improving tumor-specific homing of CAR T cells. These findings identify the ST3GAL1-βII-spectrin axis as a major cell-intrinsic program for cancer-targeting CAR T cell migration and as a promising strategy for effective T cell immunotherapy.
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Affiliation(s)
- Yeonsun Hong
- Department of Microbiology and Immunology, David H. Smith Center for Vaccine Biology and Immunology, University of Rochester, Rochester, NY, USA
| | - Brandon L Walling
- Department of Microbiology and Immunology, David H. Smith Center for Vaccine Biology and Immunology, University of Rochester, Rochester, NY, USA
| | - Hye-Ran Kim
- Department of Microbiology and Immunology, David H. Smith Center for Vaccine Biology and Immunology, University of Rochester, Rochester, NY, USA
| | - William S Serratelli
- Department of Microbiology and Immunology, David H. Smith Center for Vaccine Biology and Immunology, University of Rochester, Rochester, NY, USA
| | - John R Lozada
- Department of Microbiology and Immunology, David H. Smith Center for Vaccine Biology and Immunology, University of Rochester, Rochester, NY, USA
| | - Cooper J Sailer
- Department of Microbiology and Immunology, David H. Smith Center for Vaccine Biology and Immunology, University of Rochester, Rochester, NY, USA
- Department of Pathology, University of Rochester Medical Center, Rochester, NY, USA
| | - Andrea M Amitrano
- Department of Microbiology and Immunology, David H. Smith Center for Vaccine Biology and Immunology, University of Rochester, Rochester, NY, USA
- Department of Pathology, University of Rochester Medical Center, Rochester, NY, USA
| | - Kihong Lim
- Department of Microbiology and Immunology, David H. Smith Center for Vaccine Biology and Immunology, University of Rochester, Rochester, NY, USA
| | - Raj Kumar Mongre
- Department of Microbiology and Immunology, David H. Smith Center for Vaccine Biology and Immunology, University of Rochester, Rochester, NY, USA
| | - Kyun-Do Kim
- Department of Convergent Research of Emerging Virus Infection, Korea Research Institute of Chemical Technology, Daejeon, Korea
| | - Tara Capece
- Department of Microbiology and Immunology, David H. Smith Center for Vaccine Biology and Immunology, University of Rochester, Rochester, NY, USA
| | - Elena B Lomakina
- Department of Biomedical Engineering, University of Rochester Medical Center, Rochester, NY, USA
| | - Nicholas S Reilly
- Department of Physics and Astronomy, University of Rochester, Rochester, NY, USA
| | - Kevin Vo
- Department of Microbiology and Immunology, David H. Smith Center for Vaccine Biology and Immunology, University of Rochester, Rochester, NY, USA
| | - Scott A Gerber
- Department of Surgery, University of Rochester, Rochester, NY, USA
| | - Tan-Chi Fan
- Institute of Stem Cell and Translational Cancer Research, Chang Gung Memorial Hospital at Linkou and Chang Gung University, Taoyuan, Taiwan
| | - Alice Lin-Tsing Yu
- Department of Pediatrics/Hematology Oncology, University of California in San Diego, San Diego, CA, USA
| | - Patrick W Oakes
- Department of Physics and Astronomy, University of Rochester, Rochester, NY, USA
| | - Richard E Waugh
- Department of Biomedical Engineering, University of Rochester Medical Center, Rochester, NY, USA
| | - Chang-Duk Jun
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju, Korea
| | - Patrick M Reagan
- Wilmot Cancer Institute, University of Rochester Medical Center, Rochester, NY, USA
| | - Minsoo Kim
- Department of Microbiology and Immunology, David H. Smith Center for Vaccine Biology and Immunology, University of Rochester, Rochester, NY, USA.
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4
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Bonello TT, Cai D, Fletcher GC, Wiengartner K, Pengilly V, Lange KS, Liu Z, Lippincott‐Schwartz J, Kavran JM, Thompson BJ. Phase separation of Hippo signalling complexes. EMBO J 2023; 42:e112863. [PMID: 36807601 PMCID: PMC10015380 DOI: 10.15252/embj.2022112863] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 01/12/2023] [Accepted: 01/23/2023] [Indexed: 02/22/2023] Open
Abstract
The Hippo pathway was originally discovered to control tissue growth in Drosophila and includes the Hippo kinase (Hpo; MST1/2 in mammals), scaffold protein Salvador (Sav; SAV1 in mammals) and the Warts kinase (Wts; LATS1/2 in mammals). The Hpo kinase is activated by binding to Crumbs-Expanded (Crb-Ex) and/or Merlin-Kibra (Mer-Kib) proteins at the apical domain of epithelial cells. Here we show that activation of Hpo also involves the formation of supramolecular complexes with properties of a biomolecular condensate, including concentration dependence and sensitivity to starvation, macromolecular crowding, or 1,6-hexanediol treatment. Overexpressing Ex or Kib induces formation of micron-scale Hpo condensates in the cytoplasm, rather than at the apical membrane. Several Hippo pathway components contain unstructured low-complexity domains and purified Hpo-Sav complexes undergo phase separation in vitro. Formation of Hpo condensates is conserved in human cells. We propose that apical Hpo kinase activation occurs in phase separated "signalosomes" induced by clustering of upstream pathway components.
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Affiliation(s)
- Teresa T Bonello
- EMBL Australia, John Curtin School of Medical ResearchAustralian National UniversityCanberraACTAustralia
| | - Danfeng Cai
- HHMI Janelia Research CampusAshburnVAUSA
- Department of Biochemistry and Molecular BiologyBloomberg School of Public HealthBaltimoreMDUSA
| | | | - Kyler Wiengartner
- Department of Biochemistry and Molecular BiologyBloomberg School of Public HealthBaltimoreMDUSA
| | - Victoria Pengilly
- EMBL Australia, John Curtin School of Medical ResearchAustralian National UniversityCanberraACTAustralia
| | - Kimberly S Lange
- Department of Biochemistry and Molecular BiologyBloomberg School of Public HealthBaltimoreMDUSA
| | - Zhe Liu
- HHMI Janelia Research CampusAshburnVAUSA
| | | | - Jennifer M Kavran
- Department of Biochemistry and Molecular BiologyBloomberg School of Public HealthBaltimoreMDUSA
- Department of Biophysics and Biophysical Chemistry, and Department of OncologyJohns Hopkins School of MedicineBaltimoreMDUSA
| | - Barry J Thompson
- EMBL Australia, John Curtin School of Medical ResearchAustralian National UniversityCanberraACTAustralia
- Epithelial Biology LaboratoryThe Francis Crick InstituteLondonUK
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5
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Tessier A, Roux N, Boutaud L, Lunel E, Hakkakian L, Parisot M, Garfa-Traoré M, Ichkou A, Elkhartoufi N, Bole C, Nitschke P, Amiel J, Martinovic J, Encha-Razavi F, Attié-Bitach T, Thomas S. Bi-allelic variations in CRB2, encoding the crumbs cell polarity complex component 2, lead to non-communicating hydrocephalus due to atresia of the aqueduct of sylvius and central canal of the medulla. Acta Neuropathol Commun 2023; 11:29. [PMID: 36803301 PMCID: PMC9940441 DOI: 10.1186/s40478-023-01519-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2022] [Accepted: 01/23/2023] [Indexed: 02/22/2023] Open
Abstract
Congenital hydrocephalus is a common condition caused by the accumulation of cerebrospinal fluid in the ventricular system. Four major genes are currently known to be causally involved in hydrocephalus, either isolated or as a common clinical feature: L1CAM, AP1S2, MPDZ and CCDC88C. Here, we report 3 cases from 2 families with congenital hydrocephalus due to bi-allelic variations in CRB2, a gene previously reported to cause nephrotic syndrome, variably associated with hydrocephalus. While 2 cases presented with renal cysts, one case presented with isolated hydrocephalus. Neurohistopathological analysis allowed us to demonstrate that, contrary to what was previously proposed, the pathological mechanisms underlying hydrocephalus secondary to CRB2 variations are not due to stenosis but to atresia of both Sylvius Aqueduct and central medullar canal. While CRB2 has been largely shown crucial for apico-basal polarity, immunolabelling experiments in our fetal cases showed normal localization and level of PAR complex components (PKCι and PKCζ) as well as of tight (ZO-1) and adherens (β-catenin and N-Cadherin) junction molecules indicating a priori normal apicobasal polarity and cell-cell adhesion of the ventricular epithelium suggesting another pathological mechanism. Interestingly, atresia but not stenosis of Sylvius aqueduct was also described in cases with variations in MPDZ and CCDC88C encoding proteins previously linked functionally to the Crumbs (CRB) polarity complex, and all 3 being more recently involved in apical constriction, a process crucial for the formation of the central medullar canal. Overall, our findings argue for a common mechanism of CRB2, MPDZ and CCDC88C variations that might lead to abnormal apical constriction of the ventricular cells of the neural tube that will form the ependymal cells lining the definitive central canal of the medulla. Our study thus highlights that hydrocephalus related to CRB2, MPDZ and CCDC88C constitutes a separate pathogenic group of congenital non-communicating hydrocephalus with atresia of both Sylvius aqueduct and central canal of the medulla.
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Affiliation(s)
- Aude Tessier
- Service de Médecine Génomique des Maladies Rares, Hôpital Universitaire Necker-Enfants Malades, Paris, France. .,INSERM UMR 1163, Institut Imagine, Université Paris Cité, Paris, France.
| | - Nathalie Roux
- grid.412134.10000 0004 0593 9113Service de Médecine Génomique des Maladies Rares, Hôpital Universitaire Necker-Enfants Malades, Paris, France
| | - Lucile Boutaud
- grid.412134.10000 0004 0593 9113Service de Médecine Génomique des Maladies Rares, Hôpital Universitaire Necker-Enfants Malades, Paris, France ,grid.508487.60000 0004 7885 7602INSERM UMR 1163, Institut Imagine, Université Paris Cité, Paris, France
| | - Elodie Lunel
- grid.412134.10000 0004 0593 9113Service de Médecine Génomique des Maladies Rares, Hôpital Universitaire Necker-Enfants Malades, Paris, France
| | - Leila Hakkakian
- grid.412134.10000 0004 0593 9113Service de Médecine Génomique des Maladies Rares, Hôpital Universitaire Necker-Enfants Malades, Paris, France
| | - Mélanie Parisot
- grid.7429.80000000121866389Genomics Core Facility, Institut Imagine-Structure Fédérative de Recherche Necker, INSERM U1163 et INSERM US24/CNRS UAR3633, Paris Descartes Sorbonne Paris Cite University, Paris, France
| | - Meriem Garfa-Traoré
- grid.462420.6Cell Imaging Platform, INSERM-US24-CNRS UMS 3633 Structure Fédérative de Recherche Necker, Paris University, 75015 Paris, France
| | - Amale Ichkou
- grid.412134.10000 0004 0593 9113Service de Médecine Génomique des Maladies Rares, Hôpital Universitaire Necker-Enfants Malades, Paris, France
| | - Nadia Elkhartoufi
- grid.412134.10000 0004 0593 9113Service de Médecine Génomique des Maladies Rares, Hôpital Universitaire Necker-Enfants Malades, Paris, France
| | - Christine Bole
- grid.7429.80000000121866389Genomics Core Facility, Institut Imagine-Structure Fédérative de Recherche Necker, INSERM U1163 et INSERM US24/CNRS UAR3633, Paris Descartes Sorbonne Paris Cite University, Paris, France
| | - Patrick Nitschke
- grid.462336.6Bioinformatics Platform, Institut Imagine, Paris, France
| | - Jeanne Amiel
- grid.412134.10000 0004 0593 9113Service de Médecine Génomique des Maladies Rares, Hôpital Universitaire Necker-Enfants Malades, Paris, France ,grid.508487.60000 0004 7885 7602INSERM UMR 1163, Institut Imagine, Université Paris Cité, Paris, France
| | - Jelena Martinovic
- grid.413738.a0000 0000 9454 4367Unité de Foetopathologie, AP-HP, Hôpital Antoine Béclère, Groupe Hospitalo-Universitaire Paris Saclay, Clamart, France
| | - Férechté Encha-Razavi
- grid.412134.10000 0004 0593 9113Service de Médecine Génomique des Maladies Rares, Hôpital Universitaire Necker-Enfants Malades, Paris, France
| | - Tania Attié-Bitach
- Service de Médecine Génomique des Maladies Rares, Hôpital Universitaire Necker-Enfants Malades, Paris, France. .,INSERM UMR 1163, Institut Imagine, Université Paris Cité, Paris, France.
| | - Sophie Thomas
- INSERM UMR 1163, Institut Imagine, Université Paris Cité, Paris, France.
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6
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Apical-basal polarity and the control of epithelial form and function. Nat Rev Mol Cell Biol 2022; 23:559-577. [PMID: 35440694 DOI: 10.1038/s41580-022-00465-y] [Citation(s) in RCA: 89] [Impact Index Per Article: 44.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/11/2022] [Indexed: 02/02/2023]
Abstract
Epithelial cells are the most common cell type in all animals, forming the sheets and tubes that compose most organs and tissues. Apical-basal polarity is essential for epithelial cell form and function, as it determines the localization of the adhesion molecules that hold the cells together laterally and the occluding junctions that act as barriers to paracellular diffusion. Polarity must also target the secretion of specific cargoes to the apical, lateral or basal membranes and organize the cytoskeleton and internal architecture of the cell. Apical-basal polarity in many cells is established by conserved polarity factors that define the apical (Crumbs, Stardust/PALS1, aPKC, PAR-6 and CDC42), junctional (PAR-3) and lateral (Scribble, DLG, LGL, Yurt and RhoGAP19D) domains, although recent evidence indicates that not all epithelia polarize by the same mechanism. Research has begun to reveal the dynamic interactions between polarity factors and how they contribute to polarity establishment and maintenance. Elucidating these mechanisms is essential to better understand the roles of apical-basal polarity in morphogenesis and how defects in polarity contribute to diseases such as cancer.
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7
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Simões S, Lerchbaumer G, Pellikka M, Giannatou P, Lam T, Kim D, Yu J, ter Stal D, Al Kakouni K, Fernandez-Gonzalez R, Tepass U. Crumbs complex-directed apical membrane dynamics in epithelial cell ingression. J Cell Biol 2022; 221:213229. [PMID: 35588693 PMCID: PMC9123285 DOI: 10.1083/jcb.202108076] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 02/24/2022] [Accepted: 04/29/2022] [Indexed: 01/07/2023] Open
Abstract
Epithelial cells often leave their tissue context and ingress to form new cell types or acquire migratory ability to move to distant sites during development and tumor progression. Cells lose their apical membrane and epithelial adherens junctions during ingression. However, how factors that organize apical-basal polarity contribute to ingression is unknown. Here, we show that the dynamic regulation of the apical Crumbs polarity complex is crucial for normal neural stem cell ingression. Crumbs endocytosis and recycling allow ingression to occur in a normal timeframe. During early ingression, Crumbs and its complex partner the RhoGEF Cysts support myosin and apical constriction to ensure robust ingression dynamics. During late ingression, the E3-ubiquitin ligase Neuralized facilitates the disassembly of the Crumbs complex and the rapid endocytic removal of the apical cell domain. Our findings reveal a mechanism integrating cell fate, apical polarity, endocytosis, vesicle trafficking, and actomyosin contractility to promote cell ingression, a fundamental morphogenetic process observed in animal development and cancer.
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Affiliation(s)
- Sérgio Simões
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Gerald Lerchbaumer
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Milena Pellikka
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Paraskevi Giannatou
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Thomas Lam
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Dohyun Kim
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Jessica Yu
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada,Institute of Biomedical Engineering, University of Toronto, Toronto, Ontario, Canada
| | - David ter Stal
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Kenana Al Kakouni
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Rodrigo Fernandez-Gonzalez
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada,Institute of Biomedical Engineering, University of Toronto, Toronto, Ontario, Canada,Ted Rogers Centre for Heart Research, University of Toronto, Toronto, Ontario, Canada,Developmental and Stem Cell Biology Program, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Ulrich Tepass
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada,Correspondence to Ulrich Tepass:
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8
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Castiglioni VG, Ramalho JJ, Kroll JR, Stucchi R, van Beuzekom H, Schmidt R, Altelaar M, Boxem M. Identification and characterization of Crumbs polarity complex proteins in Caenorhabditis elegans. J Biol Chem 2022; 298:101786. [PMID: 35247383 PMCID: PMC9006659 DOI: 10.1016/j.jbc.2022.101786] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Revised: 02/12/2022] [Accepted: 02/16/2022] [Indexed: 11/23/2022] Open
Abstract
Crumbs proteins are evolutionarily conserved transmembrane proteins with essential roles in promoting the formation of the apical domain in epithelial cells. The short intracellular tail of Crumbs proteins are known to interact with several proteins, including the scaffolding protein PALS1 (protein associated with LIN7, Stardust in Drosophila). PALS1 in turn binds to a second scaffolding protein PATJ (PALS1-associated tight junction protein) to form the core Crumbs/PALS1/PATJ complex. While essential roles in epithelial organization have been shown for Crumbs proteins in Drosophila and mammalian systems, the three Caenorhabditis elegans crumbs genes are dispensable for epithelial polarization and development. Here, we investigated the presence and function of PALS1 and PATJ orthologs in C. elegans. We identified MAGU-2 as the C. elegans ortholog of PALS1 and show that MAGU-2 interacts with all three Crumbs proteins and localizes to the apical membrane domain of intestinal epithelial cells in a Crumbs-dependent fashion. Similar to crumbs mutants, magu-2 deletion showed no epithelial polarity defects. We also identified MPZ-1 as a candidate ortholog of PATJ based on the physical interaction with MAGU-2 and sequence similarity with PATJ proteins. However, MPZ-1 is not broadly expressed in epithelial tissues and, therefore, not likely a core component of the C. elegans Crumbs complex. Finally, we show overexpression of the Crumbs proteins EAT-20 or CRB-3 can lead to apical membrane expansion in the intestine. Our results shed light on the composition of the C. elegans Crumbs complex and indicate that the role of Crumbs proteins in promoting apical domain formation is conserved.
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Affiliation(s)
- Victoria G Castiglioni
- Division of Developmental Biology, Department of Biology, Faculty of Science, Institute of Biodynamics and Biocomplexity, Utrecht University, Utrecht, The Netherlands
| | - João J Ramalho
- Division of Developmental Biology, Department of Biology, Faculty of Science, Institute of Biodynamics and Biocomplexity, Utrecht University, Utrecht, The Netherlands
| | - Jason R Kroll
- Division of Developmental Biology, Department of Biology, Faculty of Science, Institute of Biodynamics and Biocomplexity, Utrecht University, Utrecht, The Netherlands
| | - Riccardo Stucchi
- Division of Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Institute of Biodynamics and Biocomplexity, Utrecht University, Utrecht, The Netherlands; Division of Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, The Netherlands
| | - Hanna van Beuzekom
- Division of Developmental Biology, Department of Biology, Faculty of Science, Institute of Biodynamics and Biocomplexity, Utrecht University, Utrecht, The Netherlands
| | - Ruben Schmidt
- Division of Developmental Biology, Department of Biology, Faculty of Science, Institute of Biodynamics and Biocomplexity, Utrecht University, Utrecht, The Netherlands
| | - Maarten Altelaar
- Division of Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, The Netherlands
| | - Mike Boxem
- Division of Developmental Biology, Department of Biology, Faculty of Science, Institute of Biodynamics and Biocomplexity, Utrecht University, Utrecht, The Netherlands.
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9
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Tanoue A, Katayama K, Ito Y, Joh K, Toda M, Yasuma T, D'Alessandro-Gabazza CN, Kawachi H, Yan K, Ito M, Gabazza EC, Tryggvason K, Dohi K. Podocyte-specific Crb2 knockout mice develop focal segmental glomerulosclerosis. Sci Rep 2021; 11:20556. [PMID: 34654837 PMCID: PMC8519956 DOI: 10.1038/s41598-021-00159-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 10/07/2021] [Indexed: 11/15/2022] Open
Abstract
Crb2 is a cell polarity-related type I transmembrane protein expressed in the apical membrane of podocytes. Knockdown of crb2 causes glomerular permeability defects in zebrafish, and its complete knockout causes embryonic lethality in mice. There are also reports of Crb2 mutations in patients with steroid-resistant nephrotic syndrome, although the precise mechanism is unclear. The present study demonstrated that podocyte-specific Crb2 knockout mice develop massive albuminuria and microhematuria 2-month after birth and focal segmental glomerulosclerosis and tubulointerstitial fibrosis with hemosiderin-laden macrophages at 6-month of age. Transmission and scanning electron microscopic studies demonstrated injury and foot process effacement of podocytes in 6-month aged podocyte-specific Crb2 knockout mice. The number of glomerular Wt1-positive cells and the expressions of Nphs2, Podxl, and Nphs1 were reduced in podocyte-specific Crb2 knockout mice compared to negative control mice. Human podocytes lacking CRB2 had significantly decreased F-actin positive area and were more susceptible to apoptosis than their wild-type counterparts. Overall, this study's results suggest that the specific deprivation of Crb2 in podocytes induces altered actin cytoskeleton reorganization associated with dysfunction and accelerated apoptosis of podocytes that ultimately cause focal segmental glomerulosclerosis.
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Affiliation(s)
- Akiko Tanoue
- Department of Cardiology and Nephrology, Mie University Graduate School of Medicine, 2-174 Edobashi, Tsu, Mie, 514-8507, Japan
| | - Kan Katayama
- Department of Cardiology and Nephrology, Mie University Graduate School of Medicine, 2-174 Edobashi, Tsu, Mie, 514-8507, Japan.
- Department of Medical Biochemistry and Biophysics, Karolinska Institute, Stockholm, Sweden.
| | - Yugo Ito
- Department of Medical Biochemistry and Biophysics, Karolinska Institute, Stockholm, Sweden
- Department of Pediatrics, Kyorin University School of Medicine, Tokyo, Japan
| | - Kensuke Joh
- Department of Pathology, The Jikei University School of Medicine, Tokyo, Japan
| | - Masaaki Toda
- Department of Immunology, Mie University Graduate School of Medicine, Mie, Japan
| | - Taro Yasuma
- Department of Immunology, Mie University Graduate School of Medicine, Mie, Japan
| | | | - Hiroshi Kawachi
- Department of Cell Biology, Kidney Research Center, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Kunimasa Yan
- Department of Pediatrics, Kyorin University School of Medicine, Tokyo, Japan
| | - Masaaki Ito
- Department of Cardiology and Nephrology, Mie University Graduate School of Medicine, 2-174 Edobashi, Tsu, Mie, 514-8507, Japan
| | - Esteban C Gabazza
- Department of Immunology, Mie University Graduate School of Medicine, Mie, Japan
| | - Karl Tryggvason
- Department of Medical Biochemistry and Biophysics, Karolinska Institute, Stockholm, Sweden
- Cardiovascular and Metabolic Disorders Program, Duke-NUS Medical School, Singapore, Singapore
| | - Kaoru Dohi
- Department of Cardiology and Nephrology, Mie University Graduate School of Medicine, 2-174 Edobashi, Tsu, Mie, 514-8507, Japan
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10
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Rahimi N, Ho RXY, Chandler KB, De La Cena KOC, Amraei R, Mitchel AJ, Engblom N, Costello CE. The cell adhesion molecule TMIGD1 binds to moesin and regulates tubulin acetylation and cell migration. J Biomed Sci 2021; 28:61. [PMID: 34503512 PMCID: PMC8427838 DOI: 10.1186/s12929-021-00757-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Accepted: 08/27/2021] [Indexed: 11/23/2022] Open
Abstract
Background The cell adhesion molecule transmembrane and immunoglobulin (Ig) domain containing1 (TMIGD1) is a novel tumor suppressor that plays important roles in regulating cell–cell adhesion, cell proliferation and cell cycle. However, the mechanisms of TMIGD1 signaling are not yet fully elucidated. Results TMIGD1 binds to the ERM family proteins moesin and ezrin, and an evolutionarily conserved RRKK motif on the carboxyl terminus of TMIGD1 mediates the interaction of TMIGD1 with the N-terminal ERM domains of moesin and ezrin. TMIGD1 governs the apical localization of moesin and ezrin, as the loss of TMIGD1 in mice altered apical localization of moesin and ezrin in epithelial cells. In cell culture, TMIGD1 inhibited moesin-induced filopodia-like protrusions and cell migration. More importantly, TMIGD1 stimulated the Lysine (K40) acetylation of α-tubulin and promoted mitotic spindle organization and CRISPR/Cas9-mediated knockout of moesin impaired the TMIGD1-mediated acetylation of α-tubulin and filamentous (F)-actin organization. Conclusions TMIGD1 binds to moesin and ezrin, and regulates their cellular localization. Moesin plays critical roles in TMIGD1-dependent acetylation of α-tubulin, mitotic spindle organization and cell migration. Our findings offer a molecular framework for understanding the complex functional interplay between TMIGD1 and the ERM family proteins in the regulation of cell adhesion and mitotic spindle assembly, and have wide-ranging implications in physiological and pathological processes such as cancer progression. Supplementary Information The online version contains supplementary material available at 10.1186/s12929-021-00757-z.
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Affiliation(s)
- Nader Rahimi
- Department of Pathology, School of Medicine, Boston University Medical Campus, Boston, MA, 02118, USA.
| | - Rachel X Y Ho
- Department of Pathology, School of Medicine, Boston University Medical Campus, Boston, MA, 02118, USA
| | - Kevin Brown Chandler
- Center for Biomedical Mass Spectrometry, Boston University School of Medicine, Boston, MA, 02118, USA
| | | | - Razie Amraei
- Department of Pathology, School of Medicine, Boston University Medical Campus, Boston, MA, 02118, USA
| | - Ashley J Mitchel
- Department of Pathology, School of Medicine, Boston University Medical Campus, Boston, MA, 02118, USA
| | - Nels Engblom
- Department of Pathology, School of Medicine, Boston University Medical Campus, Boston, MA, 02118, USA
| | - Catherine E Costello
- Center for Biomedical Mass Spectrometry, Boston University School of Medicine, Boston, MA, 02118, USA.
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11
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Biehler C, Rothenberg KE, Jette A, Gaude HM, Fernandez-Gonzalez R, Laprise P. Pak1 and PP2A antagonize aPKC function to support cortical tension induced by the Crumbs-Yurt complex. eLife 2021; 10:67999. [PMID: 34212861 PMCID: PMC8282337 DOI: 10.7554/elife.67999] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Accepted: 06/30/2021] [Indexed: 12/26/2022] Open
Abstract
The Drosophila polarity protein Crumbs is essential for the establishment and growth of the apical domain in epithelial cells. The protein Yurt limits the ability of Crumbs to promote apical membrane growth, thereby defining proper apical/lateral membrane ratio that is crucial for forming and maintaining complex epithelial structures such as tubes or acini. Here, we show that Yurt also increases Myosin-dependent cortical tension downstream of Crumbs. Yurt overexpression thus induces apical constriction in epithelial cells. The kinase aPKC phosphorylates Yurt, thereby dislodging the latter from the apical domain and releasing apical tension. In contrast, the kinase Pak1 promotes Yurt dephosphorylation through activation of the phosphatase PP2A. The Pak1–PP2A module thus opposes aPKC function and supports Yurt-induced apical constriction. Hence, the complex interplay between Yurt, aPKC, Pak1, and PP2A contributes to the functional plasticity of Crumbs. Overall, our data increase our understanding of how proteins sustaining epithelial cell polarization and Myosin-dependent cell contractility interact with one another to control epithelial tissue architecture.
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Affiliation(s)
- Cornelia Biehler
- Centre de Recherche sur le Cancer, Université Laval, Québec, Canada.,axe oncologie du Centre de Recherche du Centre Hospitalier Universitaire de Québec-UL, Québec, Canada
| | - Katheryn E Rothenberg
- Institute of Biomedical Engineering, University of Toronto, Toronto, Canada.,Ted Rogers Centre for Heart Research, University of Toronto, Toronto, Canada
| | - Alexandra Jette
- Centre de Recherche sur le Cancer, Université Laval, Québec, Canada.,axe oncologie du Centre de Recherche du Centre Hospitalier Universitaire de Québec-UL, Québec, Canada
| | - Helori-Mael Gaude
- Centre de Recherche sur le Cancer, Université Laval, Québec, Canada.,axe oncologie du Centre de Recherche du Centre Hospitalier Universitaire de Québec-UL, Québec, Canada
| | - Rodrigo Fernandez-Gonzalez
- Institute of Biomedical Engineering, University of Toronto, Toronto, Canada.,Ted Rogers Centre for Heart Research, University of Toronto, Toronto, Canada.,Department of Cell and Systems Biology, University of Toronto, Toronto, Canada.,Developmental and Stem Cell Biology Program, The Hospital for Sick Children, Toronto, Canada
| | - Patrick Laprise
- Centre de Recherche sur le Cancer, Université Laval, Québec, Canada.,axe oncologie du Centre de Recherche du Centre Hospitalier Universitaire de Québec-UL, Québec, Canada
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12
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Pojer JM, Saiful Hilmi AJ, Kondo S, Harvey KF. Crumbs and the apical spectrin cytoskeleton regulate R8 cell fate in the Drosophila eye. PLoS Genet 2021; 17:e1009146. [PMID: 34097697 PMCID: PMC8211197 DOI: 10.1371/journal.pgen.1009146] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 06/17/2021] [Accepted: 05/11/2021] [Indexed: 12/31/2022] Open
Abstract
The Hippo pathway is an important regulator of organ growth and cell fate. In the R8 photoreceptor cells of the Drosophila melanogaster eye, the Hippo pathway controls the fate choice between one of two subtypes that express either the blue light-sensitive Rhodopsin 5 (Hippo inactive R8 subtype) or the green light-sensitive Rhodopsin 6 (Hippo active R8 subtype). The degree to which the mechanism of Hippo signal transduction and the proteins that mediate it are conserved in organ growth and R8 cell fate choice is currently unclear. Here, we identify Crumbs and the apical spectrin cytoskeleton as regulators of R8 cell fate. By contrast, other proteins that influence Hippo-dependent organ growth, such as the basolateral spectrin cytoskeleton and Ajuba, are dispensable for the R8 cell fate choice. Surprisingly, Crumbs promotes the Rhodopsin 5 cell fate, which is driven by Yorkie, rather than the Rhodopsin 6 cell fate, which is driven by Warts and the Hippo pathway, which contrasts with its impact on Hippo activity in organ growth. Furthermore, neither the apical spectrin cytoskeleton nor Crumbs appear to regulate the Hippo pathway through mechanisms that have been observed in growing organs. Together, these results show that only a subset of Hippo pathway proteins regulate the R8 binary cell fate decision and that aspects of Hippo signalling differ between growing organs and post-mitotic R8 cells.
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Affiliation(s)
- Jonathan M. Pojer
- Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia
- Sir Peter MacCallum Department of Oncology, The University of Melbourne, Parkville, Victoria, Australia
| | - Abdul Jabbar Saiful Hilmi
- Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia
- Sir Peter MacCallum Department of Oncology, The University of Melbourne, Parkville, Victoria, Australia
| | - Shu Kondo
- Laboratory of Invertebrate Genetics, National Institute of Genetics, Mishima, Shizuoka, Japan
| | - Kieran F. Harvey
- Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia
- Sir Peter MacCallum Department of Oncology, The University of Melbourne, Parkville, Victoria, Australia
- Department of Anatomy and Developmental Biology, Monash University, Clayton, Victoria, Australia
- * E-mail:
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13
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Badmos H, Cobbe N, Campbell A, Jackson R, Bennett D. Drosophila USP22/nonstop polarizes the actin cytoskeleton during collective border cell migration. J Cell Biol 2021; 220:212101. [PMID: 33988679 PMCID: PMC8129793 DOI: 10.1083/jcb.202007005] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 02/06/2021] [Accepted: 04/23/2021] [Indexed: 01/04/2023] Open
Abstract
Polarization of the actin cytoskeleton is vital for the collective migration of cells in vivo. During invasive border cell migration in Drosophila, actin polarization is directly controlled by the Hippo signaling complex, which resides at contacts between border cells in the cluster. Here, we identify, in a genetic screen for deubiquitinating enzymes involved in border cell migration, an essential role for nonstop/USP22 in the expression of Hippo pathway components expanded and merlin. Loss of nonstop function consequently leads to a redistribution of F-actin and the polarity determinant Crumbs, loss of polarized actin protrusions, and tumbling of the border cell cluster. Nonstop is a component of the Spt-Ada-Gcn5-acetyltransferase (SAGA) transcriptional coactivator complex, but SAGA’s histone acetyltransferase module, which does not bind to expanded or merlin, is dispensable for migration. Taken together, our results uncover novel roles for SAGA-independent nonstop/USP22 in collective cell migration, which may help guide studies in other systems where USP22 is necessary for cell motility and invasion.
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Affiliation(s)
- Hammed Badmos
- Department of Biochemistry, Institute of Integrative Biology, University of Liverpool, Liverpool, UK.,Department of Molecular Physiology and Cell Signalling, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, UK
| | - Neville Cobbe
- Department of Biochemistry, Institute of Integrative Biology, University of Liverpool, Liverpool, UK
| | - Amy Campbell
- Department of Biochemistry, Institute of Integrative Biology, University of Liverpool, Liverpool, UK
| | - Richard Jackson
- Liverpool Clinical Trials Centre, University of Liverpool, Liverpool, UK
| | - Daimark Bennett
- Department of Biochemistry, Institute of Integrative Biology, University of Liverpool, Liverpool, UK.,Department of Molecular Physiology and Cell Signalling, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, UK
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14
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Gauthier KD, Rocheleau CE. Golgi localization of the LIN-2/7/10 complex points to a role in basolateral secretion of LET-23 EGFR in the Caenorhabditiselegans vulval precursor cells. Development 2021; 148:dev194167. [PMID: 33526581 PMCID: PMC10692275 DOI: 10.1242/dev.194167] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Accepted: 01/25/2021] [Indexed: 12/28/2022]
Abstract
The evolutionarily conserved LIN-2 (CASK)/LIN-7 (Lin7A-C)/LIN-10 (APBA1) complex plays an important role in regulating spatial organization of membrane proteins and signaling components. In Caenorhabditiselegans, the complex is essential for the development of the vulva by promoting the localization of the sole Epidermal growth factor receptor (EGFR) ortholog LET-23 to the basolateral membrane of the vulva precursor cells where it can specify the vulval cell fate. To understand how the LIN-2/7/10 complex regulates receptor localization, we determined its expression and localization during vulva development. We found that LIN-7 colocalizes with LET-23 EGFR at the basolateral membrane, whereas the LIN-2/7/10 complex colocalizes with LET-23 EGFR at cytoplasmic punctae that mostly overlap with the Golgi. Furthermore, LIN-10 recruits LIN-2, which in turn recruits LIN-7. We demonstrate that the complex forms in vivo with a particularly strong interaction and colocalization between LIN-2 and LIN-7, consistent with them forming a subcomplex. Thus, the LIN-2/7/10 complex forms on the Golgi on which it likely targets LET-23 EGFR trafficking to the basolateral membrane rather than functioning as a tether.
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Affiliation(s)
- Kimberley D Gauthier
- Division of Endocrinology and Metabolism, Department of Medicine, and Department of Anatomy and Cell Biology, McGill University; and the Metabolic Disorders and Complications Program, Centre for Translational Biology, Research Institute of the McGill University Health Centre, Montreal, QC H4A 3J1, Canada
| | - Christian E Rocheleau
- Division of Endocrinology and Metabolism, Department of Medicine, and Department of Anatomy and Cell Biology, McGill University; and the Metabolic Disorders and Complications Program, Centre for Translational Biology, Research Institute of the McGill University Health Centre, Montreal, QC H4A 3J1, Canada
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15
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Recruitment of Polarity Complexes and Tight Junction Proteins to the Site of Apical Bulk Endocytosis. Cell Mol Gastroenterol Hepatol 2021; 12:59-80. [PMID: 33548596 PMCID: PMC8082271 DOI: 10.1016/j.jcmgh.2021.01.022] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Revised: 01/19/2021] [Accepted: 01/20/2021] [Indexed: 12/19/2022]
Abstract
BACKGROUND & AIMS The molecular motor, Myosin Vb (MYO5B), is well documented for its role in trafficking cargo to the apical membrane of epithelial cells. Despite its involvement in regulating apical proteins, the role of MYO5B in cell polarity is less clear. Inactivating mutations in MYO5B result in microvillus inclusion disease (MVID), a disorder characterized by loss of key apical transporters and the presence of intracellular inclusions in enterocytes. We previously identified that inclusions in Myo5b knockout (KO) mice form from invagination of the apical brush border via apical bulk endocytosis. Herein, we sought to elucidate the role of polarity complexes and tight junction proteins during the formation of inclusions. METHODS Intestinal tissue from neonatal control and Myo5b KO littermates was analyzed by immunofluorescence to determine the localization of polarity complexes and tight junction proteins. RESULTS Proteins that make up the apical polarity complexes-Crumbs3 and Pars complexes-were associated with inclusions in Myo5b KO mice. In addition, tight junction proteins were observed to be concentrated over inclusions that were present at the apical membrane of Myo5b-deficient enterocytes in vivo and in vitro. Our mouse findings are complemented by immunostaining in a large animal swine model of MVID genetically engineered to express a human MVID-associated mutation that shows an accumulation of Claudin-2 over forming inclusions. The findings from our swine model of MVID suggest that a similar mechanism of tight junction accumulation occurs in patients with MVID. CONCLUSIONS These data show that apical bulk endocytosis involves the altered localization of apical polarity proteins and tight junction proteins after loss of Myo5b.
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16
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Martin E, Girardello R, Dittmar G, Ludwig A. New insights into the organization and regulation of the apical polarity network in mammalian epithelial cells. FEBS J 2021; 288:7073-7095. [DOI: 10.1111/febs.15710] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 01/05/2021] [Accepted: 01/11/2021] [Indexed: 12/11/2022]
Affiliation(s)
- Eleanor Martin
- School of Biological Sciences Nanyang Technological University Singapore City Singapore
- Proteomics of Cellular Signaling Luxembourg Institute of Health Strassen Luxembourg
| | - Rossana Girardello
- School of Biological Sciences Nanyang Technological University Singapore City Singapore
- Proteomics of Cellular Signaling Luxembourg Institute of Health Strassen Luxembourg
| | - Gunnar Dittmar
- Proteomics of Cellular Signaling Luxembourg Institute of Health Strassen Luxembourg
- Department of Life Sciences and Medicine University of Luxembourg Luxembourg
| | - Alexander Ludwig
- School of Biological Sciences Nanyang Technological University Singapore City Singapore
- NTU Institute of Structural Biology (NISB) Experimental Medicine Building Nanyang Technological University Singapore City Singapore
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17
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Ramalho JJ, Sepers JJ, Nicolle O, Schmidt R, Cravo J, Michaux G, Boxem M. C-terminal phosphorylation modulates ERM-1 localization and dynamics to control cortical actin organization and support lumen formation during Caenorhabditiselegans development. Development 2020; 147:dev188011. [PMID: 32586975 PMCID: PMC10755404 DOI: 10.1242/dev.188011] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Accepted: 06/13/2020] [Indexed: 12/31/2023]
Abstract
ERM proteins are conserved regulators of cortical membrane specialization that function as membrane-actin linkers and molecular hubs. The activity of ERM proteins requires a conformational switch from an inactive cytoplasmic form into an active membrane- and actin-bound form, which is thought to be mediated by sequential PIP2 binding and phosphorylation of a conserved C-terminal threonine residue. Here, we use the single Caenorhabditiselegans ERM ortholog, ERM-1, to study the contribution of these regulatory events to ERM activity and tissue formation in vivo Using CRISPR/Cas9-generated erm-1 mutant alleles, we demonstrate that a PIP2-binding site is crucially required for ERM-1 function. By contrast, dynamic regulation of C-terminal T544 phosphorylation is not essential but modulates ERM-1 apical localization and dynamics in a tissue-specific manner, to control cortical actin organization and support lumen formation in epithelial tubes. Our work highlights the dynamic nature of ERM protein regulation during tissue morphogenesis and the importance of C-terminal phosphorylation in fine-tuning ERM activity in a tissue-specific context.
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Affiliation(s)
- João J Ramalho
- Division of Developmental Biology, Institute of Biodynamics and Biocomplexity, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands
| | - Jorian J Sepers
- Division of Developmental Biology, Institute of Biodynamics and Biocomplexity, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands
| | - Ophélie Nicolle
- Univ Rennes, CNRS, IGDR (Institut de Génétique et de Développement de Rennes), UMR 6290, F-35000 Rennes, France
| | - Ruben Schmidt
- Division of Developmental Biology, Institute of Biodynamics and Biocomplexity, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands
| | - Janine Cravo
- Division of Developmental Biology, Institute of Biodynamics and Biocomplexity, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands
| | - Grégoire Michaux
- Univ Rennes, CNRS, IGDR (Institut de Génétique et de Développement de Rennes), UMR 6290, F-35000 Rennes, France
| | - Mike Boxem
- Division of Developmental Biology, Institute of Biodynamics and Biocomplexity, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands
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18
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Ciao1 interacts with Crumbs and Xpd to regulate organ growth in Drosophila. Cell Death Dis 2020; 11:365. [PMID: 32404863 PMCID: PMC7220951 DOI: 10.1038/s41419-020-2564-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 04/27/2020] [Accepted: 04/27/2020] [Indexed: 11/09/2022]
Abstract
Ciao1 is a component of the cytosolic iron-sulfur cluster assembly (CIA) complex along with MMS19 and MIP18. Xeroderma pigmentosum group D (XPD), a DNA helicase involved in regulation of cell cycle and transcription, is a CIA target for iron-sulfur (Fe/S) modification. In vivo function of Ciao1 and Xpd in developing animals has been rarely studied. Here, we reveal that Ciao1 interacts with Crumbs (Crb), Galla, and Xpd to regulate organ growth in Drosophila. Abnormal growth of eye by overexpressing Crb intracellular domain (Crbintra) is suppressed by reducing the Ciao1 level. Loss of Ciao1 or Xpd causes similar impairment in organ growth. RNAi knockdown of both Ciao1 and Xpd show similar phenotypes as Ciao1 or Xpd RNAi alone, suggesting their function in a pathway. Growth defects caused by Ciao1 RNAi are suppressed by overexpression of Xpd. Ciao1 physically interacts with Crbintra, Galla, and Xpd, supporting their genetic interactions. Remarkably, Xpd RNAi defects can also be suppressed by Ciao1 overexpression, implying a mutual regulation between the two genes. Ciao1 mutant clones in imaginal discs show decreased levels of Cyclin E (CycE) and death-associated inhibitor of apoptosis 1 (Diap1). Xpd mutant clones share the similar reduction of CycE and Diap1. Consequently, knockdown of Ciao1 and Xpd by RNAi show increased apoptotic cell death. Further, CycE overexpression is sufficient to restore the growth defects from Ciao1 RNAi or Xpd RNAi. Interestingly, Diap1 overexpression in Ciao1 mutant clones induces CycE expression, suggesting that reduced CycE in Ciao1 mutant cells is secondary to loss of Diap1. Taken together, this study reveals new roles of Ciao1 and Xpd in cell survival and growth through regulating Diap1 level during organ development.
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19
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Li L, Li H, Wang L, Wu S, Lv L, Tahir A, Xiao X, Wong CKC, Sun F, Ge R, Cheng CY. Role of cell polarity and planar cell polarity (PCP) proteins in spermatogenesis. Crit Rev Biochem Mol Biol 2020; 55:71-87. [PMID: 32207344 DOI: 10.1080/10409238.2020.1742091] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Studies on cell polarity proteins and planar cell polarity (PCP) proteins date back to almost 40 years ago in Drosophila and C. elegans when these proteins were shown to be crucial to support apico-basal polarity and also directional alignment of polarity cells across the plane of an epithelium during morphogenesis. In adult mammals, cell polarity and PCP are most notable in cochlear hair cells. However, the role of these two groups of proteins to support spermatogenesis was not explored until a decade earlier when several proteins that confer cell polarity and PCP proteins were identified in the rat testis. Since then, there are several reports appearing in the literature to examine the role of both cell polarity and PCP in supporting spermatogenesis. Herein, we provide an overview regarding the role of cell polarity and PCP proteins in the testis, evaluating these findings in light of studies in other mammalian epithelial cells/tissues. Our goal is to provide a timely evaluation of these findings, and provide some thought provoking remarks to guide future studies based on an evolving concept in the field.
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Affiliation(s)
- Linxi Li
- The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou, China.,Center for Biomedical Research, The Mary M. Wohlford Laboratory for Male Contraceptive Research, Population Council, New York, USA
| | - Huitao Li
- The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou, China.,Center for Biomedical Research, The Mary M. Wohlford Laboratory for Male Contraceptive Research, Population Council, New York, USA
| | - Lingling Wang
- Center for Biomedical Research, The Mary M. Wohlford Laboratory for Male Contraceptive Research, Population Council, New York, USA
| | - Siwen Wu
- The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou, China.,Center for Biomedical Research, The Mary M. Wohlford Laboratory for Male Contraceptive Research, Population Council, New York, USA
| | - Lixiu Lv
- The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou, China
| | - Anam Tahir
- The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou, China
| | - Xiang Xiao
- Department of Reproductive Physiology, Zhejiang Academy of Medical Sciences, Hangzhou, China
| | - Chris K C Wong
- Department of Biology, Croucher Institute for Environmental Sciences, Hong Kong Baptist University, Hong Kong, China
| | - Fei Sun
- Institute of Reproductive Medicine, Nantong University School of Medicine, Nantong, China
| | - Renshan Ge
- The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou, China
| | - C Yan Cheng
- The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou, China.,Center for Biomedical Research, The Mary M. Wohlford Laboratory for Male Contraceptive Research, Population Council, New York, USA
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20
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Aguilar-Aragon M, Fletcher G, Thompson BJ. The cytoskeletal motor proteins Dynein and MyoV direct apical transport of Crumbs. Dev Biol 2020; 459:126-137. [PMID: 31881198 PMCID: PMC7090908 DOI: 10.1016/j.ydbio.2019.12.009] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 12/17/2019] [Accepted: 12/17/2019] [Indexed: 12/12/2022]
Abstract
Crumbs (Crb in Drosophila; CRB1-3 in mammals) is a transmembrane determinant of epithelial cell polarity and a regulator of Hippo signalling. Crb is normally localized to apical cell-cell contacts, just above adherens junctions, but how apical trafficking of Crb is regulated in epithelial cells remains unclear. We use the Drosophila follicular epithelium to demonstrate that polarized trafficking of Crb is mediated by transport along microtubules by the motor protein Dynein and along actin filaments by the motor protein Myosin-V (MyoV). Blocking transport of Crb-containing vesicles by Dynein or MyoV leads to accumulation of Crb within Rab11 endosomes, rather than apical delivery. The final steps of Crb delivery and stabilisation at the plasma membrane requires the exocyst complex and three apical FERM domain proteins - Merlin, Moesin and Expanded - whose simultaneous loss disrupts apical localization of Crb. Accordingly, a knock-in deletion of the Crb FERM-binding motif (FBM) also impairs apical localization. Finally, overexpression of Crb challenges this system, creating a sensitized background to identify components involved in cytoskeletal polarization, apical membrane trafficking and stabilisation of Crb at the apical domain.
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Affiliation(s)
- M Aguilar-Aragon
- The Francis Crick Institute, 1 Midland Rd, NW1 1AT, London, United Kingdom
| | - G Fletcher
- The Francis Crick Institute, 1 Midland Rd, NW1 1AT, London, United Kingdom
| | - B J Thompson
- The Francis Crick Institute, 1 Midland Rd, NW1 1AT, London, United Kingdom; The John Curtin School of Medical Research, The Australian National University, 131 Garran Rd, Acton, ACT 2601, Canberra, Australia.
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21
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Lattner J, Leng W, Knust E, Brankatschk M, Flores-Benitez D. Crumbs organizes the transport machinery by regulating apical levels of PI(4,5)P 2 in Drosophila. eLife 2019; 8:e50900. [PMID: 31697234 PMCID: PMC6881148 DOI: 10.7554/elife.50900] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Accepted: 10/25/2019] [Indexed: 12/12/2022] Open
Abstract
An efficient vectorial intracellular transport machinery depends on a well-established apico-basal polarity and is a prerequisite for the function of secretory epithelia. Despite extensive knowledge on individual trafficking pathways, little is known about the mechanisms coordinating their temporal and spatial regulation. Here, we report that the polarity protein Crumbs is essential for apical plasma membrane phospholipid-homeostasis and efficient apical secretion. Through recruiting βHeavy-Spectrin and MyosinV to the apical membrane, Crumbs maintains the Rab6-, Rab11- and Rab30-dependent trafficking and regulates the lipid phosphatases Pten and Ocrl. Crumbs knock-down results in increased apical levels of PI(4,5)P2 and formation of a novel, Moesin- and PI(4,5)P2-enriched apical membrane sac containing microvilli-like structures. Our results identify Crumbs as an essential hub required to maintain the organization of the apical membrane and the physiological activity of the larval salivary gland.
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Affiliation(s)
- Johanna Lattner
- Max-Planck Institute of Molecular Cell Biology and Genetics (MPI-CBG)DresdenGermany
| | - Weihua Leng
- Max-Planck Institute of Molecular Cell Biology and Genetics (MPI-CBG)DresdenGermany
| | - Elisabeth Knust
- Max-Planck Institute of Molecular Cell Biology and Genetics (MPI-CBG)DresdenGermany
| | - Marko Brankatschk
- The Biotechnological Center of the TU Dresden (BIOTEC)DresdenGermany
| | - David Flores-Benitez
- Max-Planck Institute of Molecular Cell Biology and Genetics (MPI-CBG)DresdenGermany
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22
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Heikenwalder M, Lorentzen A. The role of polarisation of circulating tumour cells in cancer metastasis. Cell Mol Life Sci 2019; 76:3765-3781. [PMID: 31218452 PMCID: PMC6744547 DOI: 10.1007/s00018-019-03169-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2019] [Revised: 04/23/2019] [Accepted: 05/29/2019] [Indexed: 02/06/2023]
Abstract
Metastasis is the spread of cancer cells from a primary tumour to a distant site of the body. Metastasising tumour cells have to survive and readjust to different environments, such as heterogeneous solid tissues and liquid phase in lymph- or blood circulation, which they achieve through a high degree of plasticity that renders them adaptable to varying conditions. One defining characteristic of the metastatic process is the transition of tumour cells between different polarised phenotypes, ranging from differentiated epithelial polarity to migratory front-rear polarity. Here, we review the polarisation types adopted by tumour cells during the metastatic process and describe the recently discovered single-cell polarity in liquid phase observed in circulating tumour cells. We propose that single-cell polarity constitutes a mode of polarisation of the cell cortex that is uncoupled from the intracellular polarisation machinery, which distinguishes single-cell polarity from other types of polarity identified so far. We discuss how single-cell polarity can contribute to tumour metastasis and the therapeutic potential of this new discovery.
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Affiliation(s)
- Mathias Heikenwalder
- Divison of Chronic Inflammation and Cancer, German Cancer Research Center (DKFZ), 69120, Heidelberg, Germany.
| | - Anna Lorentzen
- Department of Molecular Biology and Genetics, Aarhus University, 8000, Aarhus, Denmark.
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Bajur AT, Iyer KV, Knust E. Cytocortex-dependent dynamics of Drosophila Crumbs controls junctional stability and tension during germ band retraction. J Cell Sci 2019; 132:jcs.228338. [PMID: 31300472 DOI: 10.1242/jcs.228338] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Accepted: 07/05/2019] [Indexed: 12/21/2022] Open
Abstract
During morphogenesis, epithelia undergo dynamic rearrangements, which requires continuous remodelling of junctions and cell shape, but at the same time mechanisms preserving cell polarity and tissue integrity. Apico-basal polarity is key for the localisation of the machinery that enables cell shape changes. The evolutionarily conserved Drosophila Crumbs protein is critical for maintaining apico-basal polarity and epithelial integrity. How Crumbs is maintained in a dynamically developing embryo remains largely unknown. Here, we applied quantitative fluorescence techniques to show that, during germ band retraction, Crumbs dynamics correlates with the morphogenetic activity of the epithelium. Genetic and pharmacological perturbations revealed that the mobile pool of Crumbs is fine-tuned by the actomyosin cortex in a stage-dependent manner. Stabilisation of Crumbs at the plasma membrane depends on a proper link to the actomyosin cortex via an intact FERM-domain-binding site in its intracellular domain, loss of which leads to increased junctional tension and higher DE-cadherin (also known as Shotgun) turnover, resulting in impaired junctional rearrangements. These data define Crumbs as a mediator between polarity and junctional regulation to orchestrate epithelial remodelling in response to changes in actomyosin activity.This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Anna T Bajur
- Max-Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany
| | - K Venkatesan Iyer
- Max-Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany
| | - Elisabeth Knust
- Max-Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany
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24
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Ghimire S, Terhzaz S, Cabrero P, Romero MF, Davies SA, Dow JAT. Targeted renal knockdown of Na +/H + exchanger regulatory factor Sip1 produces uric acid nephrolithiasis in Drosophila. Am J Physiol Renal Physiol 2019; 317:F930-F940. [PMID: 31364377 DOI: 10.1152/ajprenal.00551.2018] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Nephrolithiasis is one of the most common kidney diseases, with poorly understood pathophysiology, but experimental study has been hindered by lack of experimentally tractable models. Drosophila melanogaster is a useful model organism for renal diseases because of genetic and functional similarities of Malpighian (renal) tubules with the human kidney. Here, we demonstrated function of the sex-determining region Y protein-interacting protein-1 (Sip1) gene, an ortholog of human Na+/H+ exchanger regulatory factor (NHERF1), in Drosophila Malpighian tubules and its impact on nephrolithiasis. Abundant birefringent calculi were observed in Sip1 mutant flies, and the phenotype was also observed in renal stellate cell-specific RNA interference Sip1 knockdown in otherwise normal flies, confirming a renal etiology. This phenotype was abolished in rosy mutant flies (which model human xanthinuria) and by the xanthine oxidase inhibitor allopurinol, suggesting that the calculi were of uric acid. This was confirmed by direct biochemical assay for urate. Stones rapidly dissolved when the tubule was bathed in alkaline media, suggesting that Sip1 knockdown was acidifying the tubule. SIP1 was shown to collocate with Na+/H+ exchanger isoform 2 (NHE2) and with moesin in stellate cells. Knockdown of NHE2 specifically to the stellate cells also increased renal uric acid stone formation, and so a model was developed in which SIP1 normally regulates NHE2 activity and luminal pH, ultimately leading to uric acid stone formation. Drosophila renal tubules may thus offer a useful model for urate nephrolithiasis.
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Affiliation(s)
- Saurav Ghimire
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Selim Terhzaz
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Pablo Cabrero
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Michael F Romero
- Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine and Science, Rochester, Minnesota
| | - Shireen A Davies
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Julian A T Dow
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
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Hughes SC, Simmonds AJ. Drosophila mRNA Localization During Later Development: Past, Present, and Future. Front Genet 2019; 10:135. [PMID: 30899273 PMCID: PMC6416162 DOI: 10.3389/fgene.2019.00135] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Accepted: 02/11/2019] [Indexed: 12/12/2022] Open
Abstract
Multiple mechanisms tightly regulate mRNAs during their transcription, translation, and degradation. Of these, the physical localization of mRNAs to specific cytoplasmic regions is relatively easy to detect; however, linking localization to functional regulatory roles has been more difficult to establish. Historically, Drosophila melanogaster is a highly effective model to identify localized mRNAs and has helped identify roles for this process by regulating various cell activities. The majority of the well-characterized functional roles for localizing mRNAs to sub-regions of the cytoplasm have come from the Drosophila oocyte and early syncytial embryo. At present, relatively few functional roles have been established for mRNA localization within the relatively smaller, differentiated somatic cell lineages characteristic of later development, beginning with the cellular blastoderm, and the multiple cell lineages that make up the gastrulating embryo, larva, and adult. This review is divided into three parts—the first outlines past evidence for cytoplasmic mRNA localization affecting aspects of cellular activity post-blastoderm development in Drosophila. The majority of these known examples come from highly polarized cell lineages such as differentiating neurons. The second part considers the present state of affairs where we now know that many, if not most mRNAs are localized to discrete cytoplasmic regions in one or more somatic cell lineages of cellularized embryos, larvae or adults. Assuming that the phenomenon of cytoplasmic mRNA localization represents an underlying functional activity, and correlation with the encoded proteins suggests that mRNA localization is involved in far more than neuronal differentiation. Thus, it seems highly likely that past-identified examples represent only a small fraction of localization-based mRNA regulation in somatic cells. The last part highlights recent technological advances that now provide an opportunity for probing the role of mRNA localization in Drosophila, moving beyond cataloging the diversity of localized mRNAs to a similar understanding of how localization affects mRNA activity.
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Affiliation(s)
- Sarah C Hughes
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada.,Department of Cell Biology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Andrew J Simmonds
- Department of Cell Biology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
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Skouloudaki K, Papadopoulos DK, Tomancak P, Knust E. The apical protein Apnoia interacts with Crumbs to regulate tracheal growth and inflation. PLoS Genet 2019; 15:e1007852. [PMID: 30645584 PMCID: PMC6333334 DOI: 10.1371/journal.pgen.1007852] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Accepted: 11/25/2018] [Indexed: 12/21/2022] Open
Abstract
Most organs of multicellular organisms are built from epithelial tubes. To exert their functions, tubes rely on apico-basal polarity, on junctions, which form a barrier to separate the inside from the outside, and on a proper lumen, required for gas or liquid transport. Here we identify apnoia (apn), a novel Drosophila gene required for tracheal tube elongation and lumen stability at larval stages. Larvae lacking Apn show abnormal tracheal inflation and twisted airway tubes, but no obvious defects in early steps of tracheal maturation. apn encodes a transmembrane protein, primarily expressed in the tracheae, which exerts its function by controlling the localization of Crumbs (Crb), an evolutionarily conserved apical determinant. Apn physically interacts with Crb to control its localization and maintenance at the apical membrane of developing airways. In apn mutant tracheal cells, Crb fails to localize apically and is trapped in retromer-positive vesicles. Consistent with the role of Crb in apical membrane growth, RNAi-mediated knockdown of Crb results in decreased apical surface growth of tracheal cells and impaired axial elongation of the dorsal trunk. We conclude that Apn is a novel regulator of tracheal tube expansion in larval tracheae, the function of which is mediated by Crb.
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Affiliation(s)
- Kassiani Skouloudaki
- Max-Planck Institute for Molecular Cell Biology and Genetics, Dresden, Germany
- * E-mail: (EK); (KS)
| | | | - Pavel Tomancak
- Max-Planck Institute for Molecular Cell Biology and Genetics, Dresden, Germany
| | - Elisabeth Knust
- Max-Planck Institute for Molecular Cell Biology and Genetics, Dresden, Germany
- * E-mail: (EK); (KS)
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27
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Photoreceptor actin dysregulation in syndromic and non-syndromic retinitis pigmentosa. Biochem Soc Trans 2018; 46:1463-1473. [PMID: 30464047 DOI: 10.1042/bst20180138] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Revised: 09/26/2018] [Accepted: 10/12/2018] [Indexed: 01/11/2023]
Abstract
Retinitis pigmentosa (RP) is the leading cause of inherited blindness. RP is a genetically heterogeneous disorder, with more than 100 different causal genes identified in patients. Central to disease pathogenesis is the progressive loss of retinal photoreceptors. Photoreceptors are specialised sensory neurons that exhibit a complex and highly dynamic morphology. The highly polarised and elaborated architecture of photoreceptors requires precise regulation of numerous cytoskeletal elements. In recent years, significant work has been placed on investigating the role of microtubules (specifically, the acetylated microtubular axoneme of the photoreceptor connecting cilium) and their role in normal photoreceptor function. This has been driven by the emerging field of ciliopathies, human diseases arising from mutations in genes required for cilia formation or function, of which RP is a frequently reported phenotype. Recent studies have highlighted an intimate relationship between cilia and the actin cystoskeleton. This review will focus on the role of actin in photoreceptors, examining the connection between actin dysregulation in RP.
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28
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Mapping Cellular Polarity Networks Using Mass Spectrometry-based Strategies. J Mol Biol 2018; 430:3545-3564. [DOI: 10.1016/j.jmb.2018.05.023] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Revised: 05/11/2018] [Accepted: 05/14/2018] [Indexed: 11/22/2022]
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Association of crumbs homolog-2 with mTORC1 in developing podocyte. PLoS One 2018; 13:e0202400. [PMID: 30125302 PMCID: PMC6101391 DOI: 10.1371/journal.pone.0202400] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Accepted: 08/02/2018] [Indexed: 02/06/2023] Open
Abstract
The evidence that gene mutations in the polarity determinant Crumbs homologs-2 (CRB2) cause congenital nephrotic syndrome suggests the functional importance of this gene product in podocyte development. Because another isoform, CRB3, was reported to repress the mechanistic/mammalian target of the rapamycin complex 1 (mTORC1) pathway, we examined the role of CRB2 function in developing podocytes in relation to mTORC1. In HEK-293 and MDCK cells constitutively expressing CRB2, we found that the protein localized to the apicolateral side of the cell plasma membrane and that this plasma membrane assembly required N-glycosylation. Confocal microscopy of the neonate mouse kidney revealed that both the tyrosine-phosphorylated form and non-phosphorylated form of CRB2 commence at the S-shaped body stage at the apicolateral side of podocyte precursor cells and move to foot processes in a capillary tuft pattern. The pattern of phosphorylated mTOR in developing podocytes was similar to that of CRB2 tyrosine phosphorylation. Additionally, the lack of a tyrosine phosphorylation site on CRB2 led to the reduced sensitivity of mTORC1 activation in response to energy starvation. CRB2 may play an important role in the mechanistic pathway of developing podocytes through tyrosine phosphorylation by associating with mTORC1 activation.
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30
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Wirshing ACE, Cram EJ. Spectrin regulates cell contractility through production and maintenance of actin bundles in the Caenorhabditis elegans spermatheca. Mol Biol Cell 2018; 29:2433-2449. [PMID: 30091661 PMCID: PMC6233056 DOI: 10.1091/mbc.e18-06-0347] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Disruption to the contractility of cells, including smooth muscle cells of the cardiovascular system and myoepithelial cells of the glandular epithelium, contributes to the pathophysiology of contractile tissue diseases, including asthma, hypertension, and primary Sjögren's syndrome. Cell contractility is determined by myosin activity and actomyosin network organization and is mediated by hundreds of protein-protein interactions, many directly involving actin. Here we use a candidate RNA interference screen of more than 100 Caenorhabditis elegans genes with predicted actin-binding and regulatory domains to identify genes that contribute to the contractility of the somatic gonad. We identify the spectrin cytoskeleton composed of SPC-1/α-spectrin, UNC-70/β-spectrin, and SMA-1/β heavy-spectrin as required for contractility and actin organization in the myoepithelial cells of the C. elegans spermatheca. We use imaging of fixed and live animals as well as tissue- and developmental-stage-specific disruption of the spectrin cytoskeleton to show that spectrin regulates the production of prominent central actin bundles and is required for maintenance of central actin bundles throughout successive rounds of stretch and contraction. We conclude that the spectrin cytoskeleton contributes to spermathecal contractility by promoting maintenance of the robust actomyosin bundles that drive contraction.
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Affiliation(s)
| | - Erin J Cram
- Department of Biology, Northeastern University, Boston, MA 02115
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31
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Letizia A, Tosi S, Llimargas M. Morphogenetic movements affect local tissue organisation during embryonic Drosophila morphogenesis. Eur J Cell Biol 2018; 97:243-256. [DOI: 10.1016/j.ejcb.2018.03.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Revised: 03/04/2018] [Accepted: 03/13/2018] [Indexed: 11/28/2022] Open
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32
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Abstract
The Crumbs proteins are evolutionarily conserved apical transmembrane proteins. Drosophila Crumbs was discovered via its crucial role in epithelial polarity during fly embryogenesis. Crumbs proteins have variable extracellular domains but a highly conserved intracellular domain that can bind FERM and PDZ domain proteins. Mammals have three Crumbs genes and this review focuses on Crumbs3, the major Crumbs isoform expressed in mammalian epithelial cells. Although initial work has highlighted the role of Crumbs3 in polarity, more recent studies have found it has an important role in tissue morphogenesis functioning as a linker between the apical membrane and the actin cytoskeleton. In addition, recent publications have linked Crumbs3 to growth control via regulation of the Hippo/Yap pathway.
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Affiliation(s)
- Ben Margolis
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan 48109-5680
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33
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Forest E, Logeay R, Géminard C, Kantar D, Frayssinoux F, Heron-Milhavet L, Djiane A. The apical scaffold big bang binds to spectrins and regulates the growth of Drosophila melanogaster wing discs. J Cell Biol 2018; 217:1047-1062. [PMID: 29326287 PMCID: PMC5839784 DOI: 10.1083/jcb.201705107] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Revised: 10/22/2017] [Accepted: 01/02/2018] [Indexed: 12/05/2022] Open
Abstract
During development, cell proliferation is regulated, ensuring that tissues reach their correct size and shape. Forest et al. show that the Drosophila melanogaster scaffold protein big bang (Bbg) controls epithelial tissue growth without affecting epithelial polarity and architecture. Bbg interacts with spectrins at the apical cortex and promotes Yki signaling and actomyosin contractility. During development, cell numbers are tightly regulated, ensuring that tissues and organs reach their correct size and shape. Recent evidence has highlighted the intricate connections between the cytoskeleton and the regulation of the key growth control Hippo pathway. Looking for apical scaffolds regulating tissue growth, we describe that Drosophila melanogaster big bang (Bbg), a poorly characterized multi-PDZ scaffold, controls epithelial tissue growth without affecting epithelial polarity and architecture. bbg-mutant tissues are smaller, with fewer cells that are less apically constricted than normal. We show that Bbg binds to and colocalizes tightly with the β-heavy–Spectrin/Kst subunit at the apical cortex and promotes Yki activity, F-actin enrichment, and the phosphorylation of the myosin II regulatory light chain Spaghetti squash. We propose a model in which the spectrin cytoskeleton recruits Bbg to the cortex, where Bbg promotes actomyosin contractility to regulate epithelial tissue growth.
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Affiliation(s)
- Elodie Forest
- IRCM, Inserm, University of Montpellier, ICM, Montpellier, France
| | - Rémi Logeay
- IRCM, Inserm, University of Montpellier, ICM, Montpellier, France
| | - Charles Géminard
- IRCM, Inserm, University of Montpellier, ICM, Montpellier, France
| | - Diala Kantar
- IRCM, Inserm, University of Montpellier, ICM, Montpellier, France
| | | | | | - Alexandre Djiane
- IRCM, Inserm, University of Montpellier, ICM, Montpellier, France
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34
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Apodaca G. Role of Polarity Proteins in the Generation and Organization of Apical Surface Protrusions. Cold Spring Harb Perspect Biol 2018; 10:cshperspect.a027813. [PMID: 28264821 DOI: 10.1101/cshperspect.a027813] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Protruding from the apical surfaces of epithelial cells are specialized structures, including cilia, microplicae, microvilli, and stereocilia. These contribute to epithelial function by cushioning the apical surface, by amplifying its surface area to facilitate nutrient absorption, and by promoting sensory transduction and barrier function. Despite these important roles, and the diseases that result when their formation is perturbed, there remain significant gaps in our understanding of the biogenesis of apical protrusions, or the pathways that promote their organization and orientation once at the apical surface. Here, I review some general aspects of these apical structures, and then discuss our current understanding of their formation and organization with respect to proteins that specify apicobasolateral polarity and planar cell polarity.
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Affiliation(s)
- Gerard Apodaca
- Department of Medicine Renal-Electrolyte Division and the Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261
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35
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Crumbs, Moesin and Yurt regulate junctional stability and dynamics for a proper morphogenesis of the Drosophila pupal wing epithelium. Sci Rep 2017; 7:16778. [PMID: 29196707 PMCID: PMC5711895 DOI: 10.1038/s41598-017-15272-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Accepted: 10/18/2017] [Indexed: 12/21/2022] Open
Abstract
The Crumbs (Crb) complex is a key epithelial determinant. To understand its role in morphogenesis, we examined its function in the Drosophila pupal wing, an epithelium undergoing hexagonal packing and formation of planar-oriented hairs. Crb distribution is dynamic, being stabilized to the subapical region just before hair formation. Lack of crb or stardust, but not DPatj, affects hexagonal packing and delays hair formation, without impairing epithelial polarities but with increased fluctuations in cell junctions and perimeter length, fragmentation of adherens junctions and the actomyosin cytoskeleton. Crb interacts with Moesin and Yurt, FERM proteins regulating the actomyosin network. We found that Moesin and Yurt distribution at the subapical region depends on Crb. In contrast to previous reports, yurt, but not moesin, mutants phenocopy crb junctional defects. Moreover, while unaffected in crb mutants, cell perimeter increases in yurt mutant cells and decreases in the absence of moesin function. Our data suggest that Crb coordinates proper hexagonal packing and hair formation, by modulating junction integrity via Yurt and stabilizing cell perimeter via both Yurt and Moesin. The Drosophila pupal wing thus appears as a useful system to investigate the functional diversification of the Crb complex during morphogenesis, independently of its role in polarity.
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36
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Hochapfel F, Denk L, Mendl G, Schulze U, Maaßen C, Zaytseva Y, Pavenstädt H, Weide T, Rachel R, Witzgall R, Krahn MP. Distinct functions of Crumbs regulating slit diaphragms and endocytosis in Drosophila nephrocytes. Cell Mol Life Sci 2017; 74:4573-4586. [PMID: 28717874 PMCID: PMC11107785 DOI: 10.1007/s00018-017-2593-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Revised: 06/26/2017] [Accepted: 07/13/2017] [Indexed: 10/19/2022]
Abstract
Mammalian podocytes, the key determinants of the kidney's filtration barrier, differentiate from columnar epithelial cells and several key determinants of apical-basal polarity in the conventional epithelia have been shown to regulate podocyte morphogenesis and function. However, little is known about the role of Crumbs, a conserved polarity regulator in many epithelia, for slit-diaphragm formation and podocyte function. In this study, we used Drosophila nephrocytes as model system for mammalian podocytes and identified a conserved function of Crumbs proteins for cellular morphogenesis, nephrocyte diaphragm assembly/maintenance, and endocytosis. Nephrocyte-specific knock-down of Crumbs results in disturbed nephrocyte diaphragm assembly/maintenance and decreased endocytosis, which can be rescued by Drosophila Crumbs as well as human Crumbs2 and Crumbs3, which were both expressed in human podocytes. In contrast to the extracellular domain, which facilitates nephrocyte diaphragm assembly/maintenance, the intracellular FERM-interaction motif of Crumbs is essential for regulating endocytosis. Moreover, Moesin, which binds to the FERM-binding domain of Crumbs, is essential for efficient endocytosis. Thus, we describe here a new mechanism of nephrocyte development and function, which is likely to be conserved in mammalian podocytes.
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Affiliation(s)
- Florian Hochapfel
- Molecular and Cellular Anatomy, University of Regensburg, Universitätsstr. 31, 93053, Regensburg, Germany
- Medizinische Klinik und Poliklinik D, Universitätsklinikum Münster, Domagkstr. 3a, 48149, Münster, Germany
| | - Lucia Denk
- Molecular and Cellular Anatomy, University of Regensburg, Universitätsstr. 31, 93053, Regensburg, Germany
| | - Gudrun Mendl
- Molecular and Cellular Anatomy, University of Regensburg, Universitätsstr. 31, 93053, Regensburg, Germany
| | - Ulf Schulze
- Medizinische Klinik und Poliklinik D, Universitätsklinikum Münster, Domagkstr. 3a, 48149, Münster, Germany
| | - Christine Maaßen
- Molecular and Cellular Anatomy, University of Regensburg, Universitätsstr. 31, 93053, Regensburg, Germany
| | - Yulia Zaytseva
- Molecular and Cellular Anatomy, University of Regensburg, Universitätsstr. 31, 93053, Regensburg, Germany
| | - Hermann Pavenstädt
- Medizinische Klinik und Poliklinik D, Universitätsklinikum Münster, Domagkstr. 3a, 48149, Münster, Germany
| | - Thomas Weide
- Medizinische Klinik und Poliklinik D, Universitätsklinikum Münster, Domagkstr. 3a, 48149, Münster, Germany
| | - Reinhard Rachel
- Molecular and Cellular Anatomy, University of Regensburg, Universitätsstr. 31, 93053, Regensburg, Germany
| | - Ralph Witzgall
- Molecular and Cellular Anatomy, University of Regensburg, Universitätsstr. 31, 93053, Regensburg, Germany
| | - Michael P Krahn
- Molecular and Cellular Anatomy, University of Regensburg, Universitätsstr. 31, 93053, Regensburg, Germany.
- Medizinische Klinik und Poliklinik D, Universitätsklinikum Münster, Domagkstr. 3a, 48149, Münster, Germany.
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37
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Moreno-Fortuny A, Bragg L, Cossu G, Roostalu U. MCAM contributes to the establishment of cell autonomous polarity in myogenic and chondrogenic differentiation. Biol Open 2017; 6:1592-1601. [PMID: 28923978 PMCID: PMC5703611 DOI: 10.1242/bio.027771] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Cell polarity has a fundamental role in shaping the morphology of cells and growing tissues. Polarity is commonly thought to be established in response to extracellular signals. Here we used a minimal in vitro assay that enabled us to monitor the determination of cell polarity in myogenic and chondrogenic differentiation in the absence of external signalling gradients. We demonstrate that the initiation of cell polarity is regulated by melanoma cell adhesion molecule (MCAM). We found highly polarized localization of MCAM, Moesin (MSN), Scribble (SCRIB) and Van-Gogh-like 2 (VANGL2) at the distal end of elongating myotubes. Knockout of MCAM or elimination of its endocytosis motif does not impair the initiation of myogenesis or myoblast fusion, but prevents myotube elongation. MSN, SCRIB and VANGL2 remain uniformly distributed in MCAM knockout cells. We show that MCAM is also required at early stages of chondrogenic differentiation. In both myogenic and chondrogenic differentiation MCAM knockout leads to transcriptional downregulation of Scrib and enhanced MAP kinase activity. Our data demonstrates the importance of cell autonomous polarity in differentiation. Summary: CD146/MCAM regulates cell autonomous polarization and asymmetric localization of Scribble, Van-Gogh-like 2 and Moesin, which is required in skeletal muscle myotube elongation and chondrocyte differentiation.
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Affiliation(s)
- Artal Moreno-Fortuny
- Manchester Academic Health Science Centre, Division of Extracellular Matrix and Regenerative Medicine, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, M13 9PL, UK
| | - Laricia Bragg
- Manchester Academic Health Science Centre, Division of Extracellular Matrix and Regenerative Medicine, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, M13 9PL, UK
| | - Giulio Cossu
- Manchester Academic Health Science Centre, Division of Extracellular Matrix and Regenerative Medicine, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, M13 9PL, UK
| | - Urmas Roostalu
- Manchester Academic Health Science Centre, Division of Extracellular Matrix and Regenerative Medicine, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, M13 9PL, UK
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38
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Bazellières E, Aksenova V, Barthélémy-Requin M, Massey-Harroche D, Le Bivic A. Role of the Crumbs proteins in ciliogenesis, cell migration and actin organization. Semin Cell Dev Biol 2017; 81:13-20. [PMID: 29056580 DOI: 10.1016/j.semcdb.2017.10.018] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Revised: 10/09/2017] [Accepted: 10/18/2017] [Indexed: 02/07/2023]
Abstract
Epithelial cell organization relies on a set of proteins that interact in an intricate way and which are called polarity complexes. These complexes are involved in the determination of the apico-basal axis and in the positioning and stability of the cell-cell junctions called adherens junctions at the apico-lateral border in invertebrates. Among the polarity complexes, two are present at the apical side of epithelial cells. These are the Par complex including aPKC, PAR3 and PAR6 and the Crumbs complex including, CRUMBS, PALS1 and PATJ/MUPP1. These two complexes interact directly and in addition to their already well described functions, they play a role in other cellular processes such as ciliogenesis and polarized cell migration. In this review, we will focus on these aspects that involve the apical Crumbs polarity complex and its relation with the cortical actin cytoskeleton which might provide a more comprehensive hypothesis to explain the many facets of Crumbs cell and tissue properties.
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Affiliation(s)
- Elsa Bazellières
- Aix-Marseille University, CNRS, IBDM, Case 907, 13288 Marseille, Cedex 09, France
| | - Veronika Aksenova
- Aix-Marseille University, CNRS, IBDM, Case 907, 13288 Marseille, Cedex 09, France
| | | | | | - André Le Bivic
- Aix-Marseille University, CNRS, IBDM, Case 907, 13288 Marseille, Cedex 09, France.
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39
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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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40
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Hicks-Berthet J, Varelas X. Integrin-FAK-CDC42-PP1A signaling gnaws at YAP/TAZ activity to control incisor stem cells. Bioessays 2017; 39. [PMID: 28891248 DOI: 10.1002/bies.201700116] [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] [Indexed: 12/31/2022]
Abstract
How epithelial tissues are able to self-renew to maintain homeostasis and regenerate in response to injury remains a persistent question. The transcriptional effectors YAP and TAZ are increasingly being recognized as central mediators of epithelial stem cell biology, and a wealth of recent studies have been directed at understanding the control and activity of these factors. Recent work by Hu et al. has added to this knowledge, as they identify an Integrin-FAK-CDC42-PP1A signaling cascade that directs nuclear YAP/TAZ activity in stem cell populations of the mouse incisor, and define convergence on mTORC1 signaling as an important mediator of the proliferation of these cells. Here, we review recent studies on YAP/TAZ function and regulation in epithelial tissue-specific stem cells, merging the Hu et al. study together with our current knowledge of YAP/TAZ.
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Affiliation(s)
- Julia Hicks-Berthet
- Department of Biochemistry, Boston University School of Medicine, Boston, MA, USA
| | - Xaralabos Varelas
- Department of Biochemistry, Boston University School of Medicine, Boston, MA, USA
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41
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FERM domain phosphorylation and endogenous 3′UTR are not essential for regulating the function and subcellular localization of polarity protein Crumbs. J Genet Genomics 2017; 44:409-412. [DOI: 10.1016/j.jgg.2017.08.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Revised: 08/02/2017] [Accepted: 08/08/2017] [Indexed: 12/30/2022]
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42
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Perez-Mockus G, Roca V, Mazouni K, Schweisguth F. Neuralized regulates Crumbs endocytosis and epithelium morphogenesis via specific Stardust isoforms. J Cell Biol 2017; 216:1405-1420. [PMID: 28400441 PMCID: PMC5412571 DOI: 10.1083/jcb.201611196] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 02/13/2017] [Accepted: 02/23/2017] [Indexed: 11/22/2022] Open
Abstract
The E3 ubiquitin ligase Neuralized is shown to interact with a subset of the Stardust isoforms to regulate the endocytosis of the apical protein Crumbs and thereby promote epithelial remodeling during Drosophila development. Crumbs (Crb) is a conserved determinant of apical membrane identity that regulates epithelial morphogenesis in many developmental contexts. In this study, we identify the Crb complex protein Stardust (Sdt) as a target of the E3 ubiquitin ligase Neuralized (Neur) in Drosophila melanogaster. Neur interacts with and down-regulates specific Sdt isoforms containing a Neur binding motif (NBM). Using a CRISPR (clustered regularly interspaced short palindromic repeats)-induced deletion of the NBM-encoding exon, we found that Sdt is a key Neur target and that Neur acts via Sdt to down-regulate Crb. We further show that Neur promotes the endocytosis of Crb via the NBM-containing isoforms of Sdt. Although the regulation of Crb by Neur is not strictly essential, it contributes to epithelium remodeling in the posterior midgut and thereby facilitates the trans-epithelial migration of the primordial germ cells in early embryos. Thus, our study uncovers a novel regulatory mechanism for the developmental control of Crb-mediated morphogenesis.
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Affiliation(s)
- Gantas Perez-Mockus
- Department of Developmental and Stem Cell Biology, Institut Pasteur, F-75015 Paris, France.,Centre National de la Recherché Scientifique, UMR3738, F-75015 Paris, France.,Cellule Pasteur, Université Pierre et Marie Curie, F-75015 Paris, France
| | - Vanessa Roca
- Department of Developmental and Stem Cell Biology, Institut Pasteur, F-75015 Paris, France.,Centre National de la Recherché Scientifique, UMR3738, F-75015 Paris, France
| | - Khalil Mazouni
- Department of Developmental and Stem Cell Biology, Institut Pasteur, F-75015 Paris, France.,Centre National de la Recherché Scientifique, UMR3738, F-75015 Paris, France
| | - François Schweisguth
- Department of Developmental and Stem Cell Biology, Institut Pasteur, F-75015 Paris, France .,Centre National de la Recherché Scientifique, UMR3738, F-75015 Paris, France
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43
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Koch L, Feicht S, Sun R, Sen A, Krahn MP. Domain-specific functions of Stardust in Drosophila embryonic development. ROYAL SOCIETY OPEN SCIENCE 2016; 3:160776. [PMID: 28018665 PMCID: PMC5180163 DOI: 10.1098/rsos.160776] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Accepted: 10/19/2016] [Indexed: 06/06/2023]
Abstract
In Drosophila, the adaptor protein Stardust is essential for the stabilization of the polarity determinant Crumbs in various epithelial tissues, including the embryonic epidermis, the follicular epithelium and photoreceptor cells of the compound eye. In turn, Stardust recruits another adaptor protein, PATJ, to the subapical region to support adherens junction formation and morphogenetic events. Moreover, Stardust binds to Lin-7, which is dispensable in epithelial cells but functions in postsynaptic vesicle fusion. Finally, Stardust has been reported to bind directly to PAR-6, thereby linking the Crumbs-Stardust-PATJ complex to the PAR-6/aPKC complex. PAR-6 and aPKC are also capable of directly binding Bazooka (the Drosophila homologue of PAR-3) to form the PAR/aPKC complex, which is essential for apical-basal polarity and cell-cell contact formation in most epithelia. However, little is known about the physiological relevance of these interactions in the embryonic epidermis of Drosophila in vivo. Thus, we performed a structure-function analysis of the annotated domains with GFP-tagged Stardust and evaluated the localization and function of the mutant proteins in epithelial cells of the embryonic epidermis. The data presented here confirm a crucial role of the PDZ domain in binding Crumbs and recruiting the protein to the subapical region. However, the isolated PDZ domain is not capable of being recruited to the cortex, and the SH3 domain is essential to support the binding to Crumbs. Notably, the conserved N-terminal regions (ECR1 and ECR2) are not crucial for epithelial polarity. Finally, the GUK domain plays an important role for the protein's function, which is not directly linked to Crumbs stabilization, and the L27N domain is essential for epithelial polarization independently of recruiting PATJ.
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Affiliation(s)
| | | | | | | | - Michael P. Krahn
- Molecular and Cellular Anatomy, University of Regensburg, Universitätsstr. 31, 93053 Regensburg, Germany
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44
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Tilston-Lünel AM, Haley KE, Schlecht NF, Wang Y, Chatterton ALD, Moleirinho S, Watson A, Hundal HS, Prystowsky MB, Gunn-Moore FJ, Reynolds PA. Crumbs 3b promotes tight junctions in an ezrin-dependent manner in mammalian cells. J Mol Cell Biol 2016; 8:439-455. [PMID: 27190314 PMCID: PMC5055084 DOI: 10.1093/jmcb/mjw020] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Revised: 01/19/2016] [Accepted: 01/25/2016] [Indexed: 01/30/2023] Open
Abstract
Crumbs 3 (CRB3) is a component of epithelial junctions, which has been implicated in apical-basal polarity, apical identity, apical stability, cell adhesion, and cell growth. CRB3 undergoes alternative splicing to yield two variants: CRB3a and CRB3b. Here, we describe novel data demonstrating that, as with previous studies on CRB3a, CRB3b also promotes the formation of tight junctions (TJs). However, significantly we demonstrate that the 4.1-ezrin-radixin-moesin-binding motif of CRB3b is required for CRB3b functionality and that ezrin binds to the FBM of CRB3b. Furthermore, we show that ezrin contributes to CRB3b functionality and the correct distribution of TJ proteins. We demonstrate that both CRB3 isoforms are required for the production of functionally mature TJs and also the localization of ezrin to the plasma membrane. Finally, we demonstrate that reduced CRB3b expression in head and neck squamous cell carcinoma (HNSCC) correlates with cytoplasmic ezrin, a biomarker for aggressive disease, and shows evidence that while CRB3a expression has no effect, low CRB3b and high cytoplasmic ezrin expression combined may be prognostic for HNSCC.
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Affiliation(s)
- Andrew M Tilston-Lünel
- Medical and Biological Sciences Building, School of Biology, University of St Andrews, St Andrews, KY16 9TF, UK
| | - Kathryn E Haley
- Medical and Biological Sciences Building, School of Medicine, University of St Andrews, St Andrews, KY16 9TF, UK
| | - Nicolas F Schlecht
- Department of Epidemiology & Population Health, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
| | - Yanhua Wang
- Department of Epidemiology & Population Health, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
| | - Abigail L D Chatterton
- Medical and Biological Sciences Building, School of Medicine, University of St Andrews, St Andrews, KY16 9TF, UK
| | - Susana Moleirinho
- Medical and Biological Sciences Building, School of Biology, University of St Andrews, St Andrews, KY16 9TF, UK.,Medical and Biological Sciences Building, School of Medicine, University of St Andrews, St Andrews, KY16 9TF, UK.,Present address: Scripps Research Institute, Jupiter, FL, USA
| | - Ailsa Watson
- Department of Pathology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
| | - Harinder S Hundal
- Department of Pathology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
| | | | - Frank J Gunn-Moore
- Medical and Biological Sciences Building, School of Biology, University of St Andrews, St Andrews, KY16 9TF, UK
| | - Paul A Reynolds
- Medical and Biological Sciences Building, School of Medicine, University of St Andrews, St Andrews, KY16 9TF, UK
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45
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The PCP pathway regulates Baz planar distribution in epithelial cells. Sci Rep 2016; 6:33420. [PMID: 27624969 PMCID: PMC5022056 DOI: 10.1038/srep33420] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Accepted: 08/26/2016] [Indexed: 01/05/2023] Open
Abstract
The localisation of apico-basal polarity proteins along the Z-axis of epithelial cells is well understood while their distribution in the plane of the epithelium is poorly characterised. Here we provide a systematic description of the planar localisation of apico-basal polarity proteins in the Drosophila ommatidial epithelium. We show that the adherens junction proteins Shotgun and Armadillo, as well as the baso-lateral complexes, are bilateral, i.e. present on both sides of cell interfaces. In contrast, we report that other key adherens junction proteins, Bazooka and the myosin regulatory light chain (Spaghetti squash) are unilateral, i.e. present on one side of cell interfaces. Furthermore, we demonstrate that planar cell polarity (PCP) and not the apical determinants Crumbs and Par-6 control Bazooka unilaterality in cone cells. Altogether, our work unravels an unexpected organisation and combination of apico-basal, cytoskeletal and planar polarity proteins that is different on either side of cell-cell interfaces and unique for the different contacts of the same cell.
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46
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Gao Y, Xiao X, Lui WY, Lee WM, Mruk D, Cheng CY. Cell polarity proteins and spermatogenesis. Semin Cell Dev Biol 2016; 59:62-70. [PMID: 27292315 DOI: 10.1016/j.semcdb.2016.06.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Accepted: 06/08/2016] [Indexed: 02/09/2023]
Abstract
When the cross-section of a seminiferous tubule from an adult rat testes is examined microscopically, Sertoli cells and germ cells in the seminiferous epithelium are notably polarized cells. For instance, Sertoli cell nuclei are found near the basement membrane. On the other hand, tight junction (TJ), basal ectoplasmic specialization (basal ES, a testis-specific actin-rich anchoring junction), gap junction (GJ) and desmosome that constitute the blood-testis barrier (BTB) are also located near the basement membrane. The BTB, in turn, divides the epithelium into the basal and the adluminal (apical) compartments. Within the epithelium, undifferentiated spermatogonia and preleptotene spermatocytes restrictively reside in the basal compartment whereas spermatocytes and post-meiotic spermatids reside in the adluminal compartment. Furthermore, the heads of elongating/elongated spermatids point toward the basement membrane with their elongating tails toward the tubule lumen. However, the involvement of polarity proteins in this unique cellular organization, in particular the underlying molecular mechanism(s) by which polarity proteins confer cellular polarity in the seminiferous epithelium is virtually unknown until recent years. Herein, we discuss latest findings regarding the role of different polarity protein complexes or modules and how these protein complexes are working in concert to modulate Sertoli cell and spermatid polarity. These findings also illustrate polarity proteins exert their effects through the actin-based cytoskeleton mediated by actin binding and regulatory proteins, which in turn modulate adhesion protein complexes at the cell-cell interface since TJ, basal ES and GJ utilize F-actin for attachment. We also propose a hypothetical model which illustrates the antagonistic effects of these polarity proteins. This in turn provides a unique mechanism to modulate junction remodeling in the testis to support germ cell transport across the epithelium in particular the BTB during the epithelial cycle of spermatogenesis.
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Affiliation(s)
- Ying Gao
- The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council, 1230 York Ave., New York, NY 10065, United States
| | - Xiang Xiao
- The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council, 1230 York Ave., New York, NY 10065, United States; Department of Reproductive Physiology, Zhejiang Academy of Medical Sciences, Hangzhou 310013, China
| | - Wing-Yee Lui
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China
| | - Will M Lee
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China
| | - Dolores Mruk
- The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council, 1230 York Ave., New York, NY 10065, United States
| | - C Yan Cheng
- The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council, 1230 York Ave., New York, NY 10065, United States.
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47
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Djuric I, Siebrasse JP, Schulze U, Granado D, Schlüter MA, Kubitscheck U, Pavenstädt H, Weide T. The C-terminal domain controls the mobility of Crumbs 3 isoforms. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2016; 1863:1208-17. [DOI: 10.1016/j.bbamcr.2016.03.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Revised: 03/07/2016] [Accepted: 03/08/2016] [Indexed: 01/12/2023]
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48
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Khanal I, Elbediwy A, Diaz de la Loza MDC, Fletcher GC, Thompson BJ. Shot and Patronin polarise microtubules to direct membrane traffic and biogenesis of microvilli in epithelia. J Cell Sci 2016; 129:2651-9. [PMID: 27231092 PMCID: PMC4958304 DOI: 10.1242/jcs.189076] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Accepted: 05/19/2016] [Indexed: 01/08/2023] Open
Abstract
In epithelial tissues, polarisation of microtubules and actin microvilli occurs along the apical-basal axis of each cell, yet how these cytoskeletal polarisation events are coordinated remains unclear. Here, we examine the hierarchy of events during cytoskeletal polarisation in Drosophila melanogaster epithelia. Core apical-basal polarity determinants polarise the spectrin cytoskeleton to recruit the microtubule-binding proteins Patronin (CAMSAP1, CAMSAP2 and CAMSAP3 in humans) and Shortstop [Shot; MACF1 and BPAG1 (also known as DST) in humans] to the apical membrane domain. Patronin and Shot then act to polarise microtubules along the apical-basal axis to enable apical transport of Rab11 endosomes by the Nuf-Dynein microtubule motor complex. Finally, Rab11 endosomes are transferred to the MyoV (also known as Didum in Drosophila) actin motor to deliver the key microvillar determinant Cadherin 99C to the apical membrane to organise the biogenesis of actin microvilli.
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Affiliation(s)
- Ichha Khanal
- The Francis Crick Institute, 44 Lincoln's Inn Fields, London WC2A 3LY, UK
| | - Ahmed Elbediwy
- The Francis Crick Institute, 44 Lincoln's Inn Fields, London WC2A 3LY, UK
| | | | | | - Barry J Thompson
- The Francis Crick Institute, 44 Lincoln's Inn Fields, London WC2A 3LY, UK
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49
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Ng BF, Selvaraj GK, Santa-Cruz Mateos C, Grosheva I, Alvarez-Garcia I, Martín-Bermudo MD, Palacios IM. α-Spectrin and integrins act together to regulate actomyosin and columnarization, and to maintain a monolayered follicular epithelium. Development 2016; 143:1388-99. [PMID: 26952981 PMCID: PMC4852512 DOI: 10.1242/dev.130070] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Accepted: 02/18/2016] [Indexed: 12/26/2022]
Abstract
The spectrin cytoskeleton crosslinks actin to the membrane, and although it has been greatly studied in erythrocytes, much is unknown about its function in epithelia. We have studied the role of spectrins during epithelia morphogenesis using the Drosophila follicular epithelium (FE). As previously described, we show that α-Spectrin and β-Spectrin are essential to maintain a monolayered FE, but, contrary to previous work, spectrins are not required to control proliferation. Furthermore, spectrin mutant cells show differentiation and polarity defects only in the ectopic layers of stratified epithelia, similar to integrin mutants. Our results identify α-Spectrin and integrins as novel regulators of apical constriction-independent cell elongation, as α-Spectrin and integrin mutant cells fail to columnarize. Finally, we show that increasing and reducing the activity of the Rho1-Myosin II pathway enhances and decreases multilayering of α-Spectrin cells, respectively. Similarly, higher Myosin II activity enhances the integrin multilayering phenotype. This work identifies a primary role for α-Spectrin in controlling cell shape, perhaps by modulating actomyosin. In summary, we suggest that a functional spectrin-integrin complex is essential to balance adequate forces, in order to maintain a monolayered epithelium.
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Affiliation(s)
- Bing Fu Ng
- Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK
| | - Gokul Kannan Selvaraj
- Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK
| | | | - Inna Grosheva
- Centro Andaluz de Biología del Desarrollo CSIC-Univ. Pablo de Olavide, Sevilla 41013, Spain
| | - Ines Alvarez-Garcia
- Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK
| | | | - Isabel M Palacios
- Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK
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50
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Flores-Benitez D, Knust E. Crumbs is an essential regulator of cytoskeletal dynamics and cell-cell adhesion during dorsal closure in Drosophila. eLife 2015; 4. [PMID: 26544546 PMCID: PMC4718732 DOI: 10.7554/elife.07398] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Accepted: 11/06/2015] [Indexed: 12/12/2022] Open
Abstract
The evolutionarily conserved Crumbs protein is required for epithelial polarity and morphogenesis. Here we identify a novel role of Crumbs as a negative regulator of actomyosin dynamics during dorsal closure in the Drosophila embryo. Embryos carrying a mutation in the FERM (protein 4.1/ezrin/radixin/moesin) domain-binding motif of Crumbs die due to an overactive actomyosin network associated with disrupted adherens junctions. This phenotype is restricted to the amnioserosa and does not affect other embryonic epithelia. This function of Crumbs requires DMoesin, the Rho1-GTPase, class-I p21-activated kinases and the Arp2/3 complex. Data presented here point to a critical role of Crumbs in regulating actomyosin dynamics, cell junctions and morphogenesis. DOI:http://dx.doi.org/10.7554/eLife.07398.001 A layer of epithelial cells covers the body surface of animals. Epithelial cells have a property known as polarity; this means that they have two different poles, one of which is in contact with the environment. Midway through embryonic development, the Drosophila embryo is covered by two kinds of epithelial sheets; the epidermis on the front, the belly and the sides of the embryo, and the amnioserosa on the back. In the second half of embryonic development, the amnioserosa is brought into the embryo in a process called dorsal closure, while the epidermis expands around the back of the embryo to encompass it. One of the major activities driving dorsal closure is the contraction of amnioserosa cells. This contraction depends on the highly dynamic activity of the protein network that helps give cells their shape, known as the actomyosin cytoskeleton. One major question in the field is how changes in the actomyosin cytoskeleton are controlled as tissues take shape (a process known as “morphogenesis”) and how the integrity of epithelial tissues is maintained during these processes. A key regulator of epidermal and amnioserosa polarity is an evolutionarily conserved protein called Crumbs. The epithelial tissues of mutant embryos that do not produce Crumbs lose polarity and integrity, and the embryos fail to develop properly. Flores-Benitez and Knust have now studied the role of Crumbs in the morphogenesis of the amnioserosa during dorsal closure. This revealed that fly embryos that produce a mutant Crumbs protein that cannot interact with a protein called Moesin (which links the cell membrane and the actomyosin cytoskeleton) are unable to complete dorsal closure. Detailed analyses showed that this failure of dorsal closure is due to the over-activity of the actomyosin cytoskeleton in the amnioserosa. This results in increased and uncoordinated contractions of the cells, and is accompanied by defects in cell-cell adhesion that ultimately cause the amnioserosa to lose integrity. Flores-Benitez and Knust’s genetic analyses further showed that several different signalling systems participate in this process. Flores-Benitez and Knust’s results reveal an unexpected role of Crumbs in coordinating polarity, actomyosin activity and cell-cell adhesion. Further work is now needed to understand the molecular mechanisms and interactions that enable Crumbs to coordinate these processes; in particular, to unravel how Crumbs influences the periodic contractions that drive changes in cell shape. It will also be important to investigate whether Crumbs is involved in similar mechanisms that operate in other developmental events in which actomyosin oscillations have been linked to tissue morphogenesis. DOI:http://dx.doi.org/10.7554/eLife.07398.002
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Affiliation(s)
| | - Elisabeth Knust
- Max-Planck-Institute of Molecular Cell Biology and Genetics, Dresden, Germany
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