51
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Montcouquiol M, Kelley MW. Development and Patterning of the Cochlea: From Convergent Extension to Planar Polarity. Cold Spring Harb Perspect Med 2020; 10:cshperspect.a033266. [PMID: 30617059 DOI: 10.1101/cshperspect.a033266] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Within the mammalian cochlea, sensory hair cells and supporting cells are aligned in curvilinear rows that extend along the length of the tonotopic axis. In addition, all of the cells within the epithelium are uniformly polarized across the orthogonal neural-abneural axis. Finally, each hair cell is intrinsically polarized as revealed by the presence of an asymmetrically shaped and apically localized stereociliary bundle. It has been known for some time that many of the developmental processes that regulate these patterning events are mediated, to some extent, by the core planar cell polarity (PCP) pathway. This article will review more recent work demonstrating how components of the PCP pathway interact with cytoskeletal motor proteins to regulate cochlear outgrowth. Finally, a signaling pathway originally identified for its role in asymmetric cell divisions has recently been shown to mediate several aspects of intrinsic hair cell polarity, including kinocilia migration, bundle shape, and elongation.
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Affiliation(s)
- Mireille Montcouquiol
- INSERM, Neurocentre Magendie, U1215, F-33077 Bordeaux, France.,University of Bordeaux, Neurocentre Magendie, U1215, F-33077 Bordeaux, France
| | - Matthew W Kelley
- Laboratory of Cochlear Development, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland 20892
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52
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Dealing with apical–basal polarity and intercellular junctions: a multidimensional challenge for epithelial cell division. Curr Opin Cell Biol 2019; 60:75-83. [DOI: 10.1016/j.ceb.2019.04.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 04/12/2019] [Accepted: 04/16/2019] [Indexed: 02/01/2023]
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53
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Peglion F, Goehring NW. Switching states: dynamic remodelling of polarity complexes as a toolkit for cell polarization. Curr Opin Cell Biol 2019; 60:121-130. [PMID: 31295650 PMCID: PMC6906085 DOI: 10.1016/j.ceb.2019.05.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 05/07/2019] [Accepted: 05/11/2019] [Indexed: 02/04/2023]
Abstract
Polarity is defined by the segregation of cellular components along a defined axis. To polarize robustly, cells must be able to break symmetry and subsequently amplify these nascent asymmetries. Finally, asymmetric localization of signaling molecules must be translated into functional regulation of downstream effector pathways. Central to these behaviors are a diverse set of cell polarity networks. Within these networks, molecules exhibit varied behaviors, dynamically switching among different complexes and states, active versus inactive, bound versus unbound, immobile versus diffusive. This ability to switch dynamically between states is intimately connected to the ability of molecules to generate asymmetric patterns within cells. Focusing primarily on polarity pathways governed by the conserved PAR proteins, we discuss strategies enabled by these dynamic behaviors that are used by cells to polarize. We highlight not only how switching between states is linked to the ability of polarity proteins to localize asymmetrically, but also how cells take advantage of 'state switching' to regulate polarity in time and space.
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Affiliation(s)
- Florent Peglion
- Cell Polarity, Migration and Cancer Unit, Institut Pasteur, UMR3691 CNRS, Equipe Labellisée Ligue Contre le Cancer, F-75015, Paris, France
| | - Nathan W Goehring
- The Francis Crick Institute, London, UK; MRC Laboratory for Molecular Cell Biology, UCL, London, UK.
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54
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Tarchini B, Lu X. New insights into regulation and function of planar polarity in the inner ear. Neurosci Lett 2019; 709:134373. [PMID: 31295539 PMCID: PMC6732021 DOI: 10.1016/j.neulet.2019.134373] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Revised: 07/02/2019] [Accepted: 07/06/2019] [Indexed: 12/18/2022]
Abstract
Acquisition of cell polarity generates signaling and cytoskeletal asymmetry and thus underpins polarized cell behaviors during tissue morphogenesis. In epithelial tissues, both apical-basal polarity and planar polarity, which refers to cell polarization along an axis orthogonal to the apical-basal axis, are essential for epithelial morphogenesis and function. A prime example of epithelial planar polarity can be found in the auditory sensory epithelium (or organ of Corti, OC). Sensory hair cells, the sound receptors, acquire a planar polarized apical cytoskeleton which is uniformely oriented along an axis orthogonal to the longitudinal axis of the cochlear duct. Both cell-intrinsic and tissue-level planar polarity are necessary for proper perception of sound. Here we review recent insights into the novel roles and mechanisms of planar polarity signaling gained from genetic analysis in mice, focusing mainly on the OC but also with some discussions on the vestibular sensory epithelia.
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Affiliation(s)
- Basile Tarchini
- The Jackson Laboratory, Bar Harbor, ME, 04609, USA; Department of Medicine, Tufts University, Boston, 02111, MA, USA; Graduate School of Biomedical Science and Engineering (GSBSE), University of Maine, Orono, 04469, ME, USA.
| | - Xiaowei Lu
- Department of Cell Biology, University of Virginia Health System, Charlottesville, VA, 22908, USA.
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55
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New insights into apical-basal polarization in epithelia. Curr Opin Cell Biol 2019; 62:1-8. [PMID: 31505411 DOI: 10.1016/j.ceb.2019.07.017] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 07/25/2019] [Accepted: 07/26/2019] [Indexed: 11/21/2022]
Abstract
The establishment of an apical-basal axis of polarity is essential for the organization and functioning of epithelial cells. Polarization of epithelial cells is orchestrated by a network of conserved polarity regulators that establish opposing cortical domains through mutually antagonistic interactions and positive feedback loops. While our understanding is still far from complete, the molecular details behind these interactions continue to be worked out. Here, we highlight recent findings on the mechanisms that control the activity and localization of apical-basal polarity regulators, including oligomerization and higher-order complex formation, auto-inhibitory interactions, and electrostatic interactions with the plasma membrane.
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56
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Han X, Wei Y, Wu X, Gao J, Yang Z, Zhao C. PDK1 Regulates Transition Period of Apical Progenitors to Basal Progenitors by Controlling Asymmetric Cell Division. Cereb Cortex 2019; 30:406-420. [DOI: 10.1093/cercor/bhz146] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Revised: 06/09/2019] [Accepted: 06/09/2019] [Indexed: 12/18/2022] Open
Abstract
Abstract
The six-layered neocortex consists of diverse neuron subtypes. Deeper-layer neurons originate from apical progenitors (APs), while upper-layer neurons are mainly produced by basal progenitors (BPs), which are derivatives of APs. As development proceeds, an AP generates two daughter cells that comprise an AP and a deeper-layer neuron or a BP. How the transition of APs to BPs is spatiotemporally regulated is a fundamental question. Here, we report that conditional deletion of phoshpoinositide-dependent protein kinase 1 (PDK1) in mouse developing cortex achieved by crossing Emx1Cre line with Pdk1fl/fl leads to a delayed transition of APs to BPs and subsequently causes an increased output of deeper-layer neurons. We demonstrate that PDK1 is involved in the modulation of the aPKC-Par3 complex and further regulates the asymmetric cell division (ACD). We also find Hes1, a downstream effecter of Notch signal pathway is obviously upregulated. Knockdown of Hes1 or treatment with Notch signal inhibitor DAPT recovers the ACD defect in the Pdk1 cKO. Thus, we have identified a novel function of PDK1 in controlling the transition of APs to BPs.
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Affiliation(s)
- Xiaoning Han
- Key Laboratory of Developmental Genes and Human Diseases, Ministry of Education, School of Medicine, Southeast University, Nanjing 210009, China
| | - Yongjie Wei
- Key Laboratory of Developmental Genes and Human Diseases, Ministry of Education, School of Medicine, Southeast University, Nanjing 210009, China
| | - Xiaojing Wu
- Key Laboratory of Developmental Genes and Human Diseases, Ministry of Education, School of Medicine, Southeast University, Nanjing 210009, China
| | - Jun Gao
- Department of Neurobiology
- Key Laboratory of Human Functional Genomics of Jiangsu, Nanjing Medical University, Nanjing 211166, China
| | - Zhongzhou Yang
- State Key Laboratory of Pharmaceutical Biotechnology
- Ministry of Education Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Nanjing Biomedical Research Institute, Nanjing University, Nanjing 210061, China
| | - Chunjie Zhao
- Key Laboratory of Developmental Genes and Human Diseases, Ministry of Education, School of Medicine, Southeast University, Nanjing 210009, China
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57
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Pickett MA, Naturale VF, Feldman JL. A Polarizing Issue: Diversity in the Mechanisms Underlying Apico-Basolateral Polarization In Vivo. Annu Rev Cell Dev Biol 2019; 35:285-308. [PMID: 31461314 DOI: 10.1146/annurev-cellbio-100818-125134] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Polarization along an apico-basolateral axis is a hallmark of epithelial cells and is essential for their selective barrier and transporter functions, as well as for their ability to provide mechanical resiliency to organs. Loss of polarity along this axis perturbs development and is associated with a wide number of diseases. We describe three steps involved in polarization: symmetry breaking, polarity establishment, and polarity maintenance. While the proteins involved in these processes are highly conserved among epithelial tissues and species, the execution of these steps varies widely and is context dependent. We review both theoretical principles underlying these steps and recent work demonstrating how apico-basolateral polarity is established in vivo in different tissues, highlighting how developmental and physiological contexts play major roles in the execution of the epithelial polarity program.
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Affiliation(s)
- Melissa A Pickett
- Department of Biology, Stanford University, Stanford, California 94305, USA;
| | - Victor F Naturale
- Department of Biology, Stanford University, Stanford, California 94305, USA;
| | - Jessica L Feldman
- Department of Biology, Stanford University, Stanford, California 94305, USA;
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58
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Nunes de Almeida F, Walther RF, Pressé MT, Vlassaks E, Pichaud F. Cdc42 defines apical identity and regulates epithelial morphogenesis by promoting apical recruitment of Par6-aPKC and Crumbs. Development 2019; 146:dev175497. [PMID: 31405903 PMCID: PMC6703713 DOI: 10.1242/dev.175497] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Accepted: 07/10/2019] [Indexed: 01/20/2023]
Abstract
Cdc42 regulates epithelial morphogenesis together with the Par complex (Baz/Par3-Par6-aPKC), Crumbs (Crb/CRB3) and Stardust (Sdt/PALS1). However, how these proteins work together and interact during epithelial morphogenesis is not well understood. To address this issue, we used the genetically amenable Drosophila pupal photoreceptor and follicular epithelium. We show that during epithelial morphogenesis active Cdc42 accumulates at the developing apical membrane and cell-cell contacts, independently of the Par complex and Crb. However, membrane localization of Baz, Par6-aPKC and Crb all depend on Cdc42. We find that although binding of Cdc42 to Par6 is not essential for the recruitment of Par6 and aPKC to the membrane, it is required for their apical localization and accumulation, which we find also depends on Par6 retention by Crb. In the pupal photoreceptor, membrane recruitment of Par6-aPKC also depends on Baz. Our work shows that Cdc42 is required for this recruitment and suggests that this factor promotes the handover of Par6-aPKC from Baz onto Crb. Altogether, we propose that Cdc42 drives morphogenesis by conferring apical identity, Par-complex assembly and apical accumulation of Crb.
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Affiliation(s)
| | - Rhian F Walther
- MRC - Laboratory for Molecular Cell Biology, University College London, London WC1E 6BT, UK
| | - Mary T Pressé
- MRC - Laboratory for Molecular Cell Biology, University College London, London WC1E 6BT, UK
| | - Evi Vlassaks
- MRC - Laboratory for Molecular Cell Biology, University College London, London WC1E 6BT, UK
| | - Franck Pichaud
- MRC - Laboratory for Molecular Cell Biology, University College London, London WC1E 6BT, UK
- Institute for the Physics of Living Systems, University College London, London WC1E 6BT, UK
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59
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Kono K, Yoshiura S, Fujita I, Okada Y, Shitamukai A, Shibata T, Matsuzaki F. Reconstruction of Par-dependent polarity in apolar cells reveals a dynamic process of cortical polarization. eLife 2019; 8:45559. [PMID: 31172945 PMCID: PMC6555595 DOI: 10.7554/elife.45559] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2019] [Accepted: 05/16/2019] [Indexed: 12/12/2022] Open
Abstract
Cellular polarization is fundamental for various biological processes. The Par network system is conserved for cellular polarization. Its core complex consists of Par3, Par6, and aPKC. However, the general dynamic processes that occur during polarization are not well understood. Here, we reconstructed Par-dependent polarity using non-polarized Drosophila S2 cells expressing all three components endogenously in the cytoplasm. The results indicated that elevated Par3 expression induces cortical localization of the Par-complex at the interphase. Its asymmetric distribution goes through three steps: emergence of cortical dots, development of island-like structures with dynamic amorphous shapes, repeating fusion and fission, and polarized clustering of the islands. Our findings also showed that these islands contain a meshwork of unit-like segments. Furthermore, Par-complex patches resembling Par-islands exist in Drosophila mitotic neuroblasts. Thus, this reconstruction system provides an experimental paradigm to study features of the assembly process and structure of Par-dependent cell-autonomous polarity.
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Affiliation(s)
- Kalyn Kono
- Laboratory of Molecular Cell Biology and Development, Department of Animal Development and Physiology, Graduate School of Biostudies, Kyoto University, Kyoto, Japan.,Laboratory for Cell Asymmetry, RIKEN Center for Biosystems Dynamics Research, Kobe, Japan
| | - Shigeki Yoshiura
- Laboratory for Cell Asymmetry, RIKEN Center for Biosystems Dynamics Research, Kobe, Japan
| | - Ikumi Fujita
- Laboratory for Cell Asymmetry, RIKEN Center for Biosystems Dynamics Research, Kobe, Japan
| | - Yasushi Okada
- Laboratory for Cell Polarity Regulation, RIKEN Center for Biosystems Dynamics Research, Osaka, Japan.,Department of Physics, Graduate School of Science, The University of Tokyo, Tokyo, Japan.,Universal Biology Institute, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Atsunori Shitamukai
- Laboratory for Cell Asymmetry, RIKEN Center for Biosystems Dynamics Research, Kobe, Japan
| | - Tatsuo Shibata
- Laboratory for Physical Biology, RIKEN Center for Biosystems Dynamics Research, Kobe, Japan
| | - Fumio Matsuzaki
- Laboratory of Molecular Cell Biology and Development, Department of Animal Development and Physiology, Graduate School of Biostudies, Kyoto University, Kyoto, Japan.,Laboratory for Cell Asymmetry, RIKEN Center for Biosystems Dynamics Research, Kobe, Japan
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60
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Thompson BJ, McDonald NQ. Competitive Inhibition of aPKC by Par-3/Bazooka and Other Substrates. Dev Cell 2019; 49:680. [DOI: 10.1016/j.devcel.2019.05.031] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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61
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Pichaud F, Walther RF, Nunes de Almeida F. Regulation of Cdc42 and its effectors in epithelial morphogenesis. J Cell Sci 2019; 132:132/10/jcs217869. [PMID: 31113848 DOI: 10.1242/jcs.217869] [Citation(s) in RCA: 73] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Cdc42 - a member of the small Rho GTPase family - regulates cell polarity across organisms from yeast to humans. It is an essential regulator of polarized morphogenesis in epithelial cells, through coordination of apical membrane morphogenesis, lumen formation and junction maturation. In parallel, work in yeast and Caenorhabditis elegans has provided important clues as to how this molecular switch can generate and regulate polarity through localized activation or inhibition, and cytoskeleton regulation. Recent studies have revealed how important and complex these regulations can be during epithelial morphogenesis. This complexity is mirrored by the fact that Cdc42 can exert its function through many effector proteins. In epithelial cells, these include atypical PKC (aPKC, also known as PKC-3), the P21-activated kinase (PAK) family, myotonic dystrophy-related Cdc42 binding kinase beta (MRCKβ, also known as CDC42BPB) and neural Wiskott-Aldrich syndrome protein (N-WASp, also known as WASL). Here, we review how the spatial regulation of Cdc42 promotes polarity and polarized morphogenesis of the plasma membrane, with a focus on the epithelial cell type.
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Affiliation(s)
- Franck Pichaud
- MRC - Laboratory for Molecular Cell Biology, University College London, London WC1E 6BT, UK .,Institute for the Physics of Living Systems, University College London, London WC1E 6BT, UK
| | - Rhian F Walther
- MRC - Laboratory for Molecular Cell Biology, University College London, London WC1E 6BT, UK
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62
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Yang SA, Portilla JM, Mihailovic S, Huang YC, Deng WM. Oncogenic Notch Triggers Neoplastic Tumorigenesis in a Transition-Zone-like Tissue Microenvironment. Dev Cell 2019; 49:461-472.e5. [PMID: 30982664 PMCID: PMC6504601 DOI: 10.1016/j.devcel.2019.03.015] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2018] [Revised: 01/24/2019] [Accepted: 03/15/2019] [Indexed: 12/30/2022]
Abstract
During the initial stages of tumorigenesis, the tissue microenvironment where the pro-tumor cells reside plays a crucial role in determining the fate of these cells. Transition zones, where two types of epithelial cells meet, are high-risk sites for carcinogenesis, but the underlying mechanism remains largely unclear. Here, we show that persistent upregulation of Notch signaling induces neoplastic tumorigenesis in a transition zone between the salivary gland imaginal ring cells and the giant cells in Drosophila larvae. In this region, local endogenous JAK-STAT and JNK signaling creates a tissue microenvironment that is susceptible to oncogenic-Notch-induced tumorigenesis, whereas the rest of the salivary gland imaginal ring is refractory to Notch-induced tumor transformation. JNK signaling activates a matrix metalloprotease (MMP1) to promote Notch-induced tumorigenesis at the transition zone. These findings illustrate the significance of local endogenous inflammatory signaling in primary tumor formation.
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Affiliation(s)
- Sheng-An Yang
- Department of Biological Science, Florida State University, Tallahassee, FL 32306-4295, USA
| | - Juan-Martin Portilla
- Department of Biological Science, Florida State University, Tallahassee, FL 32306-4295, USA
| | - Sonja Mihailovic
- Department of Biological Science, Florida State University, Tallahassee, FL 32306-4295, USA
| | - Yi-Chun Huang
- Department of Biological Science, Florida State University, Tallahassee, FL 32306-4295, USA
| | - Wu-Min Deng
- Department of Biological Science, Florida State University, Tallahassee, FL 32306-4295, USA.
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63
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Barr J, Charania S, Gilmutdinov R, Yakovlev K, Shidlovskii Y, Schedl P. The CPEB translational regulator, Orb, functions together with Par proteins to polarize the Drosophila oocyte. PLoS Genet 2019; 15:e1008012. [PMID: 30865627 PMCID: PMC6433291 DOI: 10.1371/journal.pgen.1008012] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Revised: 03/25/2019] [Accepted: 02/12/2019] [Indexed: 01/05/2023] Open
Abstract
orb is a founding member of the CPEB family of translational regulators and is required at multiple steps during Drosophila oogenesis. Previous studies showed that orb is required during mid-oogenesis for the translation of the posterior/germline determinant oskar mRNA and the dorsal-ventral determinant gurken mRNA. Here, we report that orb also functions upstream of these axes determinants in the polarization of the microtubule network (MT). Prior to oskar and gurken translational activation, the oocyte MT network is repolarized. The MT organizing center at the oocyte posterior is disassembled, and a new MT network is established at the oocyte anterior. Repolarization depends upon cross-regulatory interactions between anterior (apical) and posterior (basal) Par proteins. We show that repolarization of the oocyte also requires orb and that orb is needed for the proper functioning of the Par proteins. orb interacts genetically with aPKC and cdc42 and in egg chambers compromised for orb activity, Par-1 and aPKC protein and aPKC mRNA are mislocalized. Moreover, like cdc42-, the defects in Par protein localization appear to be connected to abnormalities in the cortical actin cytoskeleton. These abnormalities also disrupt the localization of the spectraplakin Shot and the microtubule minus-end binding protein Patronin. These two proteins play a critical role in the repolarization of the MT network.
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Affiliation(s)
- Justinn Barr
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, United States of America
| | - Sofia Charania
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, United States of America
| | - Rudolf Gilmutdinov
- Laboratory of Gene Expression Regulation in Development, Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
| | - Konstantin Yakovlev
- Laboratory of Gene Expression Regulation in Development, Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
| | - Yulii Shidlovskii
- Laboratory of Gene Expression Regulation in Development, Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
| | - Paul Schedl
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, United States of America
- Laboratory of Gene Expression Regulation in Development, Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
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64
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Hannaford M, Loyer N, Tonelli F, Zoltner M, Januschke J. A chemical-genetics approach to study the role of atypical Protein Kinase C in Drosophila. Development 2019; 146:dev170589. [PMID: 30635282 PMCID: PMC6361133 DOI: 10.1242/dev.170589] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 12/21/2018] [Indexed: 12/11/2022]
Abstract
Studying the function of proteins using genetics in cycling cells is complicated by the fact that there is often a delay between gene inactivation and the time point of phenotypic analysis. This is particularly true when studying kinases that have pleiotropic functions and multiple substrates. Drosophila neuroblasts (NBs) are rapidly dividing stem cells and an important model system for the study of cell polarity. Mutations in multiple kinases cause NB polarity defects, but their precise functions at particular time points in the cell cycle are unknown. Here, we use chemical genetics and report the generation of an analogue-sensitive allele of Drosophila atypical Protein Kinase C (aPKC). We demonstrate that the resulting mutant aPKC kinase can be specifically inhibited in vitro and in vivo Acute inhibition of aPKC during NB polarity establishment abolishes asymmetric localization of Miranda, whereas its inhibition during NB polarity maintenance does not in the time frame of normal mitosis. However, aPKC helps to sharpen the pattern of Miranda, by keeping it off the apical and lateral cortex after nuclear envelope breakdown.
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Affiliation(s)
- Matthew Hannaford
- Cell and Developmental Biology, School of Life Sciences, University of Dundee, Dow Street, Dundee DD5 1EH, UK
| | - Nicolas Loyer
- Cell and Developmental Biology, School of Life Sciences, University of Dundee, Dow Street, Dundee DD5 1EH, UK
| | - Francesca Tonelli
- MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dow Street, Dundee DD5 1EH, UK
| | - Martin Zoltner
- Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, Dow Street, Dundee DD5 1EH, UK
| | - Jens Januschke
- Cell and Developmental Biology, School of Life Sciences, University of Dundee, Dow Street, Dundee DD5 1EH, UK
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65
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Jouette J, Guichet A, Claret SB. Dynein-mediated transport and membrane trafficking control PAR3 polarised distribution. eLife 2019; 8:40212. [PMID: 30672465 PMCID: PMC6358217 DOI: 10.7554/elife.40212] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Accepted: 01/03/2019] [Indexed: 12/14/2022] Open
Abstract
The scaffold protein PAR3 and the kinase PAR1 are essential proteins that control cell polarity. Their precise opposite localisations define plasma membrane domains with specific functions. PAR3 and PAR1 are mutually inhibited by direct or indirect phosphorylations, but their fates once phosphorylated are poorly known. Through precise spatiotemporal quantification of PAR3 localisation in the Drosophila oocyte, we identify several mechanisms responsible for its anterior cortex accumulation and its posterior exclusion. We show that PAR3 posterior plasma membrane exclusion depends on PAR1 and an endocytic mechanism relying on RAB5 and PI(4,5)P2. In a second phase, microtubules and the dynein motor, in connection with vesicular trafficking involving RAB11 and IKK-related kinase, IKKε, are required for PAR3 transport towards the anterior cortex. Altogether, our results point to a connection between membrane trafficking and dynein-mediated transport to sustain PAR3 asymmetry.
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Affiliation(s)
- Julie Jouette
- Institut Jacques Monod, CNRS, UMR 7592, Paris Diderot University, Sorbonne Paris Cité, Paris, France
| | - Antoine Guichet
- Institut Jacques Monod, CNRS, UMR 7592, Paris Diderot University, Sorbonne Paris Cité, Paris, France
| | - Sandra B Claret
- Institut Jacques Monod, CNRS, UMR 7592, Paris Diderot University, Sorbonne Paris Cité, Paris, France
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66
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Shitara A, Malec L, Ebrahim S, Chen D, Bleck C, Hoffman MP, Weigert R. Cdc42 negatively regulates endocytosis during apical membrane maintenance in live animals. Mol Biol Cell 2018; 30:324-332. [PMID: 30540520 PMCID: PMC6589572 DOI: 10.1091/mbc.e18-10-0615] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Lumen establishment and maintenance are fundamental for tubular organs physiological functions. Most of the studies investigating the mechanisms regulating this process have been carried out in cell cultures or in smaller organisms, whereas little has been done in mammalian model systems in vivo. Here we used the salivary glands of live mice to examine the role of the small GTPase Cdc42 in the regulation of the homeostasis of the intercellular canaliculi, a specialized apical domain of the acinar cells, where protein and fluid secretion occur. Depletion of Cdc42 in adult mice induced a significant expansion of the apical canaliculi, whereas depletion at late embryonic stages resulted in a complete inhibition of their postnatal formation. In addition, intravital subcellular microscopy revealed that reduced levels of Cdc42 affected membrane trafficking from and toward the plasma membrane, highlighting a novel role for Cdc42 in membrane remodeling through the negative regulation of selected endocytic pathways.
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Affiliation(s)
- Akiko Shitara
- Laboratory of Cellular and Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
| | - Lenka Malec
- Laboratory of Cellular and Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
| | - Seham Ebrahim
- Laboratory of Cellular and Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
| | - Desu Chen
- Laboratory of Cellular and Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892.,College of Computer, Mathematical, and Natural Sciences, University of Maryland, College Park, MD 20742
| | - Christopher Bleck
- Electron Microscopy Core Facility, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892
| | - Matthew P Hoffman
- Matrix and Morphogenesis Section, National Institutes of Health, Bethesda, MD 20892
| | - Roberto Weigert
- Laboratory of Cellular and Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892.,Intracellular Membrane Trafficking Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20892
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67
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Durney CH, Harris TJC, Feng JJ. Dynamics of PAR Proteins Explain the Oscillation and Ratcheting Mechanisms in Dorsal Closure. Biophys J 2018; 115:2230-2241. [PMID: 30446158 DOI: 10.1016/j.bpj.2018.10.014] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Revised: 10/09/2018] [Accepted: 10/16/2018] [Indexed: 11/30/2022] Open
Abstract
We present a vertex-based model for Drosophila dorsal closure that predicts the mechanics of cell oscillation and contraction from the dynamics of the PAR proteins. Based on experimental observations of how aPKC, Par-6, and Bazooka translocate from the circumference of the apical surface to the medial domain, and how they interact with each other and ultimately regulate the apicomedial actomyosin, we formulate a system of differential equations that captures the key features of dorsal closure, including distinctive behaviors in its early, slow, and fast phases. The oscillation in cell area in the early phase of dorsal closure results from an intracellular negative feedback loop that involves myosin, an actomyosin regulator, aPKC, and Bazooka. In the slow phase, gradual sequestration of apicomedial aPKC by Bazooka clusters causes incomplete disassembly of the actomyosin network over each cycle of oscillation, thus producing a so-called ratchet. The fast phase of rapid cell and tissue contraction arises when medial myosin, no longer antagonized by aPKC, builds up in time and produces sustained contraction. Thus, a minimal set of rules governing the dynamics of the PAR proteins, extracted from experimental observations, can account for all major mechanical outcomes of dorsal closure, including the transitions between its three distinct phases.
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Affiliation(s)
- Clinton H Durney
- Department of Mathematics, University of British Columbia, Vancouver, British Columbia, Canada
| | - Tony J C Harris
- Department of Cell & Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - James J Feng
- Department of Mathematics, University of British Columbia, Vancouver, British Columbia, Canada; Department of Chemical and Biological Engineering, University of British Columbia, Vancouver, British Columbia, Canada.
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68
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Chen J, Sayadian AC, Lowe N, Lovegrove HE, St Johnston D. An alternative mode of epithelial polarity in the Drosophila midgut. PLoS Biol 2018; 16:e3000041. [PMID: 30339698 PMCID: PMC6209374 DOI: 10.1371/journal.pbio.3000041] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 10/31/2018] [Accepted: 10/02/2018] [Indexed: 11/18/2022] Open
Abstract
Apical-basal polarity is essential for the formation and function of epithelial tissues, whereas loss of polarity is a hallmark of tumours. Studies in Drosophila have identified conserved polarity factors that define the apical (Crumbs, Stardust, Par-6, atypical protein kinase C [aPKC]), junctional (Bazooka [Baz]/Par-3), and basolateral (Scribbled [Scrib], Discs large [Dlg], Lethal [2] giant larvae [Lgl]) domains of epithelial cells. Because these conserved factors mark equivalent domains in diverse types of vertebrate and invertebrate epithelia, it is generally assumed that this system underlies polarity in all epithelia. Here, we show that this is not the case, as none of these canonical factors are required for the polarisation of the endodermal epithelium of the Drosophila adult midgut. Furthermore, like vertebrate epithelia but not other Drosophila epithelia, the midgut epithelium forms occluding junctions above adherens junctions (AJs) and requires the integrin adhesion complex for polarity. Thus, Drosophila contains two types of epithelia that polarise by fundamentally different mechanisms. This diversity of epithelial types may reflect their different developmental origins, junctional arrangement, or whether they polarise in an apical-basal direction or vice versa. Since knock-outs of canonical polarity factors in vertebrates often have little or no effect on epithelial polarity and the Drosophila midgut shares several common features with vertebrate epithelia, this diversity of polarity mechanisms is likely to be conserved in other animals.
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Affiliation(s)
- Jia Chen
- The Gurdon Institute and the Department of Genetics, University of Cambridge, Cambridge, United Kingdom
| | - Aram-Christopher Sayadian
- The Gurdon Institute and the Department of Genetics, University of Cambridge, Cambridge, United Kingdom
| | - Nick Lowe
- The Gurdon Institute and the Department of Genetics, University of Cambridge, Cambridge, United Kingdom
| | - Holly E. Lovegrove
- The Gurdon Institute and the Department of Genetics, University of Cambridge, Cambridge, United Kingdom
| | - Daniel St Johnston
- The Gurdon Institute and the Department of Genetics, University of Cambridge, Cambridge, United Kingdom
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69
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Kullmann L, Krahn MP. Redundant regulation of localization and protein stability of DmPar3. Cell Mol Life Sci 2018; 75:3269-3282. [PMID: 29523893 PMCID: PMC11105499 DOI: 10.1007/s00018-018-2792-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2017] [Revised: 03/03/2018] [Accepted: 03/07/2018] [Indexed: 11/25/2022]
Abstract
Apical-basal polarity is an important characteristic of epithelia and Drosophila neural stem cells. The conserved Par complex, which consists of the atypical protein kinase C and the scaffold proteins Baz and Par6, is a key player in the establishment of apical-basal cell polarity. Membrane recruitment of Baz has been reported to be accomplished by several mechanisms, which might function in redundancy, to ensure the correct localization of the complex. However, none of the described interactions was sufficient to displace the protein from the apical junctions. Here, we dissected the role of the oligomerization domain and the lipid-binding motif of Baz in vivo in the Drosophila embryo. We found that these domains function in redundancy to ensure the apical junctional localization of Baz: inactivation of only one domain is not sufficient to disrupt the function of Baz during apical-basal polarization of epithelial cells and neural stem cells. In contrast, mutation of both domains results in a strongly impaired protein stability and a phenotype characterized by embryonic lethality and an impaired apical-basal polarity in the embryonic epithelium and neural stem cells, resembling a baz-loss of function allele. Strikingly, the binding of Baz to the transmembrane proteins E-Cadherin, Echinoid, and Starry Night was not affected in this mutant protein. Our findings reveal a redundant function of the oligomerization and the lipid-binding domain, which is required for protein stability, correct subcellular localization, and apical-basal cell polarization.
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Affiliation(s)
- Lars Kullmann
- Molecular and Cellular Anatomy, University of Regensburg, Universitätsstr. 31, 93053, Regensburg, Germany
- Internal Medicine D, University Hospital of Münster, Domagkstr. 3a, 48149, Münster, Germany
| | - Michael P Krahn
- Molecular and Cellular Anatomy, University of Regensburg, Universitätsstr. 31, 93053, Regensburg, Germany.
- Internal Medicine D, University Hospital of Münster, Domagkstr. 3a, 48149, Münster, Germany.
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70
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Campbell FC, Loughrey MB, McClements J, Deevi RK, Javadi A, Rainey L. Mechanistic Insights into Colorectal Cancer Phenomics from Fundamental and Organotypic Model Studies. THE AMERICAN JOURNAL OF PATHOLOGY 2018; 188:1936-1948. [PMID: 30028958 PMCID: PMC6240511 DOI: 10.1016/j.ajpath.2018.05.021] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 05/02/2018] [Accepted: 05/30/2018] [Indexed: 02/08/2023]
Abstract
Colorectal cancer (CRC) diagnosis and prognostic stratification are based on histopathologic assessment of cell or nuclear pleomorphism, aberrant mitotic figures, altered glandular architecture, and other phenomic abnormalities. This complexity is driven by oncogenic perturbation of tightly coordinated spatiotemporal signaling to disrupt multiple scales of tissue organization. This review clarifies molecular and cellular mechanisms underlying common CRC histologic features and helps understand how the CRC genome controls core aspects of tumor aggressiveness. It further explores a spatiotemporal framework for CRC phenomics based on regulation of living cells in fundamental and organotypic model systems. The review also discusses tissue homeostasis, considers distinct classes of oncogenic perturbations, and evolution of cellular or multicellular cancer phenotypes. It further explores the molecular controls of cribriform, micropapillary, and high-grade CRC morphology in organotypic culture models and assesses relevant translational studies. In addition, the review delves into complexities of morphologic plasticity whereby a single molecular signature generates heterogeneous cancer phenotypes, and, conversely, morphologically homogeneous tumors show substantive molecular diversity. Principles outlined may aid mechanistic interpretation of omics data in a setting of cancer pathology, provide insight into CRC consensus molecular subtypes, and better define principles for CRC prognostic stratification.
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Affiliation(s)
- Frederick C Campbell
- Centre for Cancer Research and Cell Biology, Queen's University of Belfast, Belfast, United Kingdom; Belfast Health and Social Care Trust, Belfast, United Kingdom.
| | - Maurice Bernard Loughrey
- Centre for Cancer Research and Cell Biology, Queen's University of Belfast, Belfast, United Kingdom; Belfast Health and Social Care Trust, Belfast, United Kingdom; Northern Ireland Molecular Pathology Laboratory, Belfast, United Kingdom
| | - Jane McClements
- Centre for Cancer Research and Cell Biology, Queen's University of Belfast, Belfast, United Kingdom
| | - Ravi Kiran Deevi
- Centre for Cancer Research and Cell Biology, Queen's University of Belfast, Belfast, United Kingdom
| | - Arman Javadi
- Centre for Cancer Research and Cell Biology, Queen's University of Belfast, Belfast, United Kingdom
| | - Lisa Rainey
- Centre for Cancer Research and Cell Biology, Queen's University of Belfast, Belfast, United Kingdom
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71
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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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72
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Gamblin CL, Parent-Prévost F, Jacquet K, Biehler C, Jetté A, Laprise P. Oligomerization of the FERM-FA protein Yurt controls epithelial cell polarity. J Cell Biol 2018; 217:3853-3862. [PMID: 30082297 PMCID: PMC6219725 DOI: 10.1083/jcb.201803099] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Revised: 07/18/2018] [Accepted: 07/24/2018] [Indexed: 12/24/2022] Open
Abstract
Drosophila melanogaster Yurt (Yrt) and its mammalian orthologue EPB41L5 limit apical membrane growth in polarized epithelia. EPB41L5 also supports epithelial-mesenchymal transition and metastasis. Yrt and EPB41L5 contain a four-point-one, ezrin, radixin, and moesin (FERM) domain and a FERM-adjacent (FA) domain. The former contributes to the quaternary structure of 50 human proteins, whereas the latter defines a subfamily of 14 human FERM proteins and fulfills unknown roles. In this study, we show that both Yrt and EPB41L5 oligomerize. Our data also establish that the FERM-FA unit forms an oligomeric interface and that multimerization of Yrt is crucial for its function in epithelial cell polarity regulation. Finally, we demonstrate that aPKC destabilizes the Yrt oligomer to repress its functions, thereby revealing a mechanism through which this kinase supports apical domain formation. Overall, our study highlights a conserved biochemical property of fly and human Yrt proteins, describes a novel function of the FA domain, and further characterizes the molecular mechanisms sustaining epithelial cell polarity.
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Affiliation(s)
- Clémence L Gamblin
- Centre de Recherche sur le Cancer de l'Université Laval, and Axe Oncologie du Centre de Recherche du Centre Hospitalier Universitaire de Québec-Université Laval, Québec City, Canada
| | - Frédérique Parent-Prévost
- Centre de Recherche sur le Cancer de l'Université Laval, and Axe Oncologie du Centre de Recherche du Centre Hospitalier Universitaire de Québec-Université Laval, Québec City, Canada
| | - Kévin Jacquet
- Centre de Recherche sur le Cancer de l'Université Laval, and Axe Oncologie du Centre de Recherche du Centre Hospitalier Universitaire de Québec-Université Laval, Québec City, Canada
| | - Cornélia Biehler
- Centre de Recherche sur le Cancer de l'Université Laval, and Axe Oncologie du Centre de Recherche du Centre Hospitalier Universitaire de Québec-Université Laval, Québec City, Canada
| | - Alexandra Jetté
- Centre de Recherche sur le Cancer de l'Université Laval, and Axe Oncologie du Centre de Recherche du Centre Hospitalier Universitaire de Québec-Université Laval, Québec City, Canada
| | - Patrick Laprise
- Centre de Recherche sur le Cancer de l'Université Laval, and Axe Oncologie du Centre de Recherche du Centre Hospitalier Universitaire de Québec-Université Laval, Québec City, Canada
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73
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Szymborska A, Gerhardt H. Hold Me, but Not Too Tight-Endothelial Cell-Cell Junctions in Angiogenesis. Cold Spring Harb Perspect Biol 2018; 10:cshperspect.a029223. [PMID: 28851748 DOI: 10.1101/cshperspect.a029223] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Endothelial cell-cell junctions must perform seemingly incompatible tasks during vascular development-providing stable connections that prevent leakage, while allowing dynamic cellular rearrangements during sprouting, anastomosis, lumen formation, and functional remodeling of the vascular network. This review aims to highlight recent insights into the molecular mechanisms governing endothelial cell-cell adhesion in the context of vascular development.
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Affiliation(s)
- Anna Szymborska
- Integrative Vascular Biology Laboratory, Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), 13125, Berlin, Germany.,DZHK (German Centre for Cardiovascular Research), partner site Berlin
| | - Holger Gerhardt
- Integrative Vascular Biology Laboratory, Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), 13125, Berlin, Germany.,Vascular Patterning Laboratory, Center for Cancer Biology, VIB, Department of Oncology, KU Leuven, 3000 Leuven, Belgium.,DZHK (German Centre for Cardiovascular Research), partner site Berlin.,Berlin Institute of Health (BIH), 10178 Berlin, Germany
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74
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Drummond ML, Li M, Tarapore E, Nguyen TTL, Barouni BJ, Cruz S, Tan KC, Oro AE, Atwood SX. Actin polymerization controls cilia-mediated signaling. J Cell Biol 2018; 217:3255-3266. [PMID: 29945904 PMCID: PMC6122990 DOI: 10.1083/jcb.201703196] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Revised: 03/29/2018] [Accepted: 05/31/2018] [Indexed: 01/20/2023] Open
Abstract
Actin polymerization is important to generate primary cilia. Drummond et al. show that upstream actin regulators are necessary for this process by controlling aPKC and Src kinase activity to promote Hedgehog signaling and restrict primary cilia. Primary cilia are polarized organelles that allow detection of extracellular signals such as Hedgehog (Hh). How the cytoskeleton supporting the cilium generates and maintains a structure that finely tunes cellular response remains unclear. Here, we find that regulation of actin polymerization controls primary cilia and Hh signaling. Disrupting actin polymerization, or knockdown of N-WASp/Arp3, increases ciliation frequency, axoneme length, and Hh signaling. Cdc42, a potent actin regulator, recruits both atypical protein pinase C iota/lambda (aPKC) and Missing-in-Metastasis (MIM) to the basal body to maintain actin polymerization and restrict axoneme length. Transcriptome analysis implicates the Src pathway as a major aPKC effector. aPKC promotes whereas MIM antagonizes Src activity to maintain proper levels of primary cilia, actin polymerization, and Hh signaling. Hh pathway activation requires Smoothened-, Gli-, and Gli1-specific activation by aPKC. Surprisingly, longer axonemes can amplify Hh signaling, except when aPKC is disrupted, reinforcing the importance of the Cdc42–aPKC–Gli axis in actin-dependent regulation of primary cilia signaling.
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Affiliation(s)
- Michael L Drummond
- Department of Developmental and Cell Biology, University of California, Irvine, Irvine, CA
| | - Mischa Li
- Department of Dermatology, Program in Epithelial Biology, Stanford University School of Medicine, Stanford, CA
| | - Eric Tarapore
- Department of Developmental and Cell Biology, University of California, Irvine, Irvine, CA
| | - Tuyen T L Nguyen
- Department of Developmental and Cell Biology, University of California, Irvine, Irvine, CA
| | - Baina J Barouni
- Department of Developmental and Cell Biology, University of California, Irvine, Irvine, CA
| | - Shaun Cruz
- Department of Developmental and Cell Biology, University of California, Irvine, Irvine, CA
| | - Kevin C Tan
- Department of Developmental and Cell Biology, University of California, Irvine, Irvine, CA
| | - Anthony E Oro
- Department of Dermatology, Program in Epithelial Biology, Stanford University School of Medicine, Stanford, CA
| | - Scott X Atwood
- Department of Developmental and Cell Biology, University of California, Irvine, Irvine, CA .,Department of Dermatology, University of California, Irvine, Irvine, CA.,Chao Family Comprehensive Cancer Center, University of California, Irvine, Irvine, CA
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75
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Abstract
Establishing and maintaining cell polarity are dynamic processes that necessitate complicated but highly regulated protein interactions. Phosphorylation is a powerful mechanism for cells to control the function and subcellular localization of a target protein, and multiple kinases have played critical roles in cell polarity. Among them, atypical protein kinase C (aPKC) is likely the most studied kinase in cell polarity and has the largest number of downstream substrates characterized so far. More than half of the polarity proteins that are essential for regulating cell polarity have been identified as aPKC substrates. This review covers mainly studies of aPKC in regulating anterior-posterior polarity in the worm one-cell embryo and apical-basal polarity in epithelial cells and asymmetrically dividing cells (for example,
Drosophila neuroblasts). We will go through aPKC target proteins in cell polarity and discuss various mechanisms by which aPKC phosphorylation controls their subcellular localizations and biological functions. We will also review the recent progress in determining the detailed molecular mechanisms in spatial and temporal control of aPKC subcellular localization and kinase activity during cell polarization.
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Affiliation(s)
- Yang Hong
- Department of Cell Biology, University of Pittsburgh School of Medicine, S325 BST, 3500 Terrace Street, Pittsburgh, PA 15261, USA
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76
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Serrate/Notch Signaling Regulates the Size of the Progenitor Cell Pool in Drosophila Imaginal Rings. Genetics 2018; 209:829-843. [PMID: 29773559 DOI: 10.1534/genetics.118.300963] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Accepted: 05/16/2018] [Indexed: 12/20/2022] Open
Abstract
Drosophila imaginal rings are larval tissues composed of progenitor cells that are essential for the formation of adult foreguts, hindguts, and salivary glands. Specified from subsets of ectoderm in the embryo, imaginal ring cells are kept quiescent until midsecond larval instar, and undergo rapid proliferation during the third instar to attain adequate numbers of cells that will replace apoptotic larval tissues for adult organ formation. Here, we show that Notch signaling is activated in all three imaginal rings from middle embryonic stage to early pupal stage, and that Notch signaling positively controls cell proliferation in all three imaginal rings during the third larval instar. Our mutant clonal analysis, knockdown, and gain-of-function studies indicate that canonical Notch pathway components are involved in regulating the proliferation of these progenitor cells. Both trans-activation and cis-inhibition between the ligand and receptor control Notch activation in the imaginal ring. Serrate (Ser) is the ligand provided from neighboring imaginal ring cells that trans-activates Notch signaling, whereas both Ser and Delta (Dl) could cis-inhibit Notch activity when the ligand and the receptor are in the same cell. In addition, we show that Notch signaling expressed in middle embryonic and first larval stages is required for the initial size of imaginal rings. Taken together, these findings indicate that imaginal rings are excellent in vivo models to decipher how progenitor cell number and proliferation are developmentally regulated, and that Notch signaling in these imaginal tissues is the primary growth-promoting signal that controls the size of the progenitor cell pool.
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77
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Wang H, Qiu Z, Xu Z, Chen SJ, Luo J, Wang X, Chen J. aPKC is a key polarity determinant in coordinating the function of three distinct cell polarities during collective migration. Development 2018; 145:dev.158444. [PMID: 29636381 DOI: 10.1242/dev.158444] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Accepted: 04/03/2018] [Indexed: 12/30/2022]
Abstract
Apical-basal polarity is a hallmark of epithelia and needs to be remodeled when epithelial cells undergo morphogenetic cell movements. Here, we analyze border cells in the Drosophila ovary to address how apical-basal polarity is remodeled and turned into front-back and inside-outside as well as apical-basal polarities, during collective migration. We find that the Crumbs (Crb) complex is required for the generation of the three distinct but interconnected cell polarities of border cells. Specifically, the Crb complex, together with the Par complex and the endocytic recycling machinery, ensures the strict distribution of two distinct populations of aPKC at the inside apical junction and near the outside lateral membrane. Interestingly, aPKC distributed near the outside lateral membrane interacts with Sif and promotes Rac-induced protrusions, whereas alteration of the aPKC distribution pattern changes the pattern of protrusion formation, leading to disruption of all three polarities. Therefore, we demonstrate that aPKC, spatially controlled by the Crb complex, is a key polarity molecule coordinating the generation of three distinct but interconnected cell polarities during collective migration.
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Affiliation(s)
- Heng Wang
- State Key Laboratory of Pharmaceutical Biotechnology and MOE Key Laboratory of Model Animals for Disease Study, Model Animal Research Center, Nanjing University, 12 Xue-fu Road, Nanjing, China 210061
| | - Zhiqian Qiu
- State Key Laboratory of Pharmaceutical Biotechnology and MOE Key Laboratory of Model Animals for Disease Study, Model Animal Research Center, Nanjing University, 12 Xue-fu Road, Nanjing, China 210061
| | - Zehao Xu
- State Key Laboratory of Pharmaceutical Biotechnology and MOE Key Laboratory of Model Animals for Disease Study, Model Animal Research Center, Nanjing University, 12 Xue-fu Road, Nanjing, China 210061
| | - Samuel John Chen
- State Key Laboratory of Pharmaceutical Biotechnology and MOE Key Laboratory of Model Animals for Disease Study, Model Animal Research Center, Nanjing University, 12 Xue-fu Road, Nanjing, China 210061
| | - Jun Luo
- State Key Laboratory of Pharmaceutical Biotechnology and MOE Key Laboratory of Model Animals for Disease Study, Model Animal Research Center, Nanjing University, 12 Xue-fu Road, Nanjing, China 210061
| | - Xiaobo Wang
- LBCMCP, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 31062 Toulouse, France
| | - Jiong Chen
- State Key Laboratory of Pharmaceutical Biotechnology and MOE Key Laboratory of Model Animals for Disease Study, Model Animal Research Center, Nanjing University, 12 Xue-fu Road, Nanjing, China 210061
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78
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Schmidt A, Grosshans J. Dynamics of cortical domains in early Drosophila development. J Cell Sci 2018; 131:131/7/jcs212795. [DOI: 10.1242/jcs.212795] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
ABSTRACT
Underlying the plasma membrane of eukaryotic cells is an actin cortex that includes actin filaments and associated proteins. A special feature of all polarized and epithelial cells are cortical domains, each of which is characterized by specific sets of proteins. Typically, an epithelial cell contains apical, subapical, lateral and basal domains. The domain-specific protein sets contain evolutionarily conserved proteins, as well as cell-type-specific factors. Among the conserved proteins are, the Par proteins, Crumbs complex and the lateral proteins Scribbled and Discs large 1. Organization of the plasma membrane into cortical domains is dynamic and depends on cell type, differentiation and developmental stage. The dynamics of cortical organization is strikingly visible in early Drosophila embryos, which increase the number of distinct cortical domains from one, during the pre-blastoderm stage, to two in syncytial blastoderm embryos, before finally acquiring the four domains that are typical for epithelial cells during cellularization. In this Review, we will describe the dynamics of cortical organization in early Drosophila embryos and discuss the processes and mechanisms underlying cortical remodeling.
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Affiliation(s)
- Anja Schmidt
- Institute for Developmental Biochemistry, Medical School, University of Göttingen, 37077 Göttingen, Germany
| | - Jörg Grosshans
- Institute for Developmental Biochemistry, Medical School, University of Göttingen, 37077 Göttingen, Germany
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79
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Steinbacher T, Kummer D, Ebnet K. Junctional adhesion molecule-A: functional diversity through molecular promiscuity. Cell Mol Life Sci 2018; 75:1393-1409. [PMID: 29238845 PMCID: PMC11105642 DOI: 10.1007/s00018-017-2729-0] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Revised: 12/04/2017] [Accepted: 12/11/2017] [Indexed: 12/27/2022]
Abstract
Cell adhesion molecules (CAMs) of the immunoglobulin superfamily (IgSF) regulate important processes such as cell proliferation, differentiation and morphogenesis. This activity is primarily due to their ability to initiate intracellular signaling cascades at cell-cell contact sites. Junctional adhesion molecule-A (JAM-A) is an IgSF-CAM with a short cytoplasmic tail that has no catalytic activity. Nevertheless, JAM-A is involved in a variety of biological processes. The functional diversity of JAM-A resides to a large part in a C-terminal PDZ domain binding motif which directly interacts with nine different PDZ domain-containing proteins. The molecular promiscuity of its PDZ domain motif allows JAM-A to recruit protein scaffolds to specific sites of cell-cell adhesion and to assemble signaling complexes at those sites. Here, we review the molecular characteristics of JAM-A, including its dimerization, its interaction with scaffolding proteins, and the phosphorylation of its cytoplasmic domain, and we describe how these characteristics translate into diverse biological activities.
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Affiliation(s)
- Tim Steinbacher
- Institute-Associated Research Group: Cell Adhesion and Cell Polarity, Institute of Medical Biochemistry, ZMBE, University of Münster, Von-Esmarch-Str. 56, 48149, Münster, Germany
- Cells-In-Motion Cluster of Excellence (EXC1003-CiM), University of Münster, Münster, Germany
| | - Daniel Kummer
- Institute-Associated Research Group: Cell Adhesion and Cell Polarity, Institute of Medical Biochemistry, ZMBE, University of Münster, Von-Esmarch-Str. 56, 48149, Münster, Germany
- Interdisciplinary Clinical Research Center (IZKF), University of Münster, Münster, Germany
| | - Klaus Ebnet
- Institute-Associated Research Group: Cell Adhesion and Cell Polarity, Institute of Medical Biochemistry, ZMBE, University of Münster, Von-Esmarch-Str. 56, 48149, Münster, Germany.
- Cells-In-Motion Cluster of Excellence (EXC1003-CiM), University of Münster, Münster, Germany.
- Interdisciplinary Clinical Research Center (IZKF), University of Münster, Münster, Germany.
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80
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Pichaud F. PAR-Complex and Crumbs Function During Photoreceptor Morphogenesis and Retinal Degeneration. Front Cell Neurosci 2018; 12:90. [PMID: 29651238 PMCID: PMC5884931 DOI: 10.3389/fncel.2018.00090] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Accepted: 03/15/2018] [Indexed: 12/30/2022] Open
Abstract
The fly photoreceptor has long been used as a model to study sensory neuron morphogenesis and retinal degeneration. In particular, elucidating how these cells are built continues to help further our understanding of the mechanisms of polarized cell morphogenesis, intracellular trafficking and the causes of human retinal pathologies. The conserved PAR complex, which in flies consists of Cdc42-PAR6-aPKC-Bazooka, and the transmembrane protein Crumbs (Crb) are key players during photoreceptor morphogenesis. While the PAR complex regulates polarity in many cell types, Crb function in polarity is relatively specific to epithelial cells. Together Cdc42-PAR6-aPKC-Bazooka and Crb orchestrate the differentiation of the photoreceptor apical membrane (AM) and zonula adherens (ZA), thus allowing these cells to assemble into a neuro-epithelial lattice. In addition to its function in epithelial polarity, Crb has also been shown to protect fly photoreceptors from light-induced degeneration, a process linked to Rhodopsin expression and trafficking. Remarkably, mutations in the human Crumbs1 (CRB1) gene lead to retinal degeneration, making the fly photoreceptor a powerful disease model system.
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Affiliation(s)
- Franck Pichaud
- Medical Research Council, Laboratory for Molecular Cell Biology, University College London, London, United Kingdom
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81
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Walther RF, Burki M, Pinal N, Rogerson C, Pichaud F. Rap1, Canoe and Mbt cooperate with Bazooka to promote zonula adherens assembly in the fly photoreceptor. J Cell Sci 2018; 131:jcs207779. [PMID: 29507112 PMCID: PMC5897711 DOI: 10.1242/jcs.207779] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Accepted: 02/07/2018] [Indexed: 12/25/2022] Open
Abstract
In Drosophila epithelial cells, apical exclusion of Bazooka (the Drosophila Par3 protein) defines the position of the zonula adherens (ZA), which demarcates the apical and lateral membrane and allows cells to assemble into sheets. Here, we show that the small GTPase Rap1, its effector Canoe (Cno) and the Cdc42 effector kinase Mushroom bodies tiny (Mbt), converge in regulating epithelial morphogenesis by coupling stabilization of the adherens junction (AJ) protein E-Cadherin and Bazooka retention at the ZA. Furthermore, our results show that the localization of Rap1, Cno and Mbt at the ZA is interdependent, indicating that their functions during ZA morphogenesis are interlinked. In this context, we find the Rap1-GEF Dizzy is enriched at the ZA and our results suggest that it promotes Rap1 activity during ZA morphogenesis. Altogether, we propose the Dizzy, Rap1 and Cno pathway and Mbt converge in regulating the interface between Bazooka and AJ material to promote ZA morphogenesis.
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Affiliation(s)
- Rhian F Walther
- MRC Laboratory for Molecular Cell Biology, University College London, Gower Street, London WC1E 6BT, UK
| | - Mubarik Burki
- MRC Laboratory for Molecular Cell Biology, University College London, Gower Street, London WC1E 6BT, UK
| | - Noelia Pinal
- MRC Laboratory for Molecular Cell Biology, University College London, Gower Street, London WC1E 6BT, UK
| | - Clare Rogerson
- MRC Laboratory for Molecular Cell Biology, University College London, Gower Street, London WC1E 6BT, UK
| | - Franck Pichaud
- MRC Laboratory for Molecular Cell Biology, University College London, Gower Street, London WC1E 6BT, UK
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82
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Renschler FA, Bruekner SR, Salomon PL, Mukherjee A, Kullmann L, Schütz-Stoffregen MC, Henzler C, Pawson T, Krahn MP, Wiesner S. Structural basis for the interaction between the cell polarity proteins Par3 and Par6. Sci Signal 2018; 11:11/517/eaam9899. [PMID: 29440511 DOI: 10.1126/scisignal.aam9899] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Polarity is a fundamental property of most cell types. The Par protein complex is a major driving force in generating asymmetrically localized protein networks and consists of atypical protein kinase C (aPKC), Par3, and Par6. Dysfunction of this complex causes developmental abnormalities and diseases such as cancer. We identified a PDZ domain-binding motif in Par6 that was essential for its interaction with Par3 in vitro and for Par3-mediated membrane localization of Par6 in cultured cells. In fly embryos, we observed that the PDZ domain-binding motif was functionally redundant with the PDZ domain in targeting Par6 to the cortex of epithelial cells. Our structural analyses by x-ray crystallography and NMR spectroscopy showed that both the PDZ1 and PDZ3 domains but not the PDZ2 domain in Par3 engaged in a canonical interaction with the PDZ domain-binding motif in Par6. Par3 thus has the potential to recruit two Par6 proteins simultaneously, which may facilitate the assembly of polarity protein networks through multivalent PDZ domain interactions.
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Affiliation(s)
- Fabian A Renschler
- Max Planck Institute for Developmental Biology, Max-Planck-Ring 5, 72076 Tübingen, Germany
| | - Susanne R Bruekner
- Max Planck Institute for Developmental Biology, Max-Planck-Ring 5, 72076 Tübingen, Germany
| | - Paulin L Salomon
- Max Planck Institute for Developmental Biology, Max-Planck-Ring 5, 72076 Tübingen, Germany
| | - Amrita Mukherjee
- Max Planck Institute for Developmental Biology, Max-Planck-Ring 5, 72076 Tübingen, Germany
| | - Lars Kullmann
- Molecular and Cellular Anatomy, University of Regensburg, Universitätsstrasse 31, 93053 Regensburg, Germany
| | | | - Christine Henzler
- Max Planck Institute for Developmental Biology, Max-Planck-Ring 5, 72076 Tübingen, Germany
| | - Tony Pawson
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, 600 University Avenue, Toronto, Ontario M5G 1X5, Canada
| | - Michael P Krahn
- Molecular and Cellular Anatomy, University of Regensburg, Universitätsstrasse 31, 93053 Regensburg, Germany.,Medical Clinic D, University Hospital of Münster, Domagkstraβe 3a, 48149 Münster, Germany
| | - Silke Wiesner
- Max Planck Institute for Developmental Biology, Max-Planck-Ring 5, 72076 Tübingen, Germany.
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83
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Abstract
Selective enrichment of the polyphosphoinositides (PPIn), such as PtdIns(4,5)P2 and PtdIns4P, helps to determine the identity of the plasma membrane (PM) and regulates many aspects of cell biology through a vast number of protein effectors. Polarity proteins had long been assumed to be non-PPIn-binding proteins that mainly associate with PM/cell cortex through their extensive protein-protein interaction network. However, recent studies began to reveal that several key polarity proteins electrostatically bind to PPIn through their positively charged protein domains or structures and such PPIn-binding property is essential for their direct and specific attachment to PM. Although the physical nature of the charge-based PPIn binding appears to be simple and nonspecific, it serves as an elegant mechanism that can be efficiently and specifically regulated for achieving polarized PM targeting of polarity proteins. As an unexpected consequence, subcellular localization of PPIn-binding polarity proteins are also subject to regulations by physiological conditions such as hypoxia and ischemia that acutely and reversibly depletes PPIn from PM.
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Affiliation(s)
- Gerald R Hammond
- Department of Cell Biology, University of Pittsburgh Medical School, Pittsburgh, Pennsylvania 15261
| | - Yang Hong
- Department of Cell Biology, University of Pittsburgh Medical School, Pittsburgh, Pennsylvania 15261
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84
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Takeda M, Sami MM, Wang YC. A homeostatic apical microtubule network shortens cells for epithelial folding via a basal polarity shift. Nat Cell Biol 2017; 20:36-45. [PMID: 29203884 DOI: 10.1038/s41556-017-0001-3] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Accepted: 09/19/2017] [Indexed: 12/27/2022]
Abstract
Epithelial folding is typically driven by localized actomyosin contractility. However, it remains unclear how epithelia deform when myosin levels are low and uniform. In the Drosophila gastrula, dorsal fold formation occurs despite a lack of localized myosin changes, while the fold-initiating cells reduce cell height following basal shifts of polarity via an unknown mechanism. We show that cell shortening depends on an apical microtubule network organized by the CAMSAP protein Patronin. Prior to gastrulation, microtubule forces generated by the minus-end motor dynein scaffold the apical cell cortex into a dome-like shape, while the severing enzyme Katanin facilitates network remodelling to ensure tissue-wide cell size homeostasis. During fold initiation, Patronin redistributes following basal polarity shifts in the initiating cells, apparently weakening the scaffolding forces to allow dome descent. The homeostatic network that ensures size/shape homogeneity is thus repurposed for cell shortening, linking epithelial polarity to folding via a microtubule-based mechanical mechanism.
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Affiliation(s)
- Michiko Takeda
- Laboratory for Epithelial Morphogenesis, RIKEN Center for Developmental Biology, Kobe, Hyogo, Japan
| | - Mustafa M Sami
- Laboratory for Epithelial Morphogenesis, RIKEN Center for Developmental Biology, Kobe, Hyogo, Japan
| | - Yu-Chiun Wang
- Laboratory for Epithelial Morphogenesis, RIKEN Center for Developmental Biology, Kobe, Hyogo, Japan.
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85
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Lang CF, Munro E. The PAR proteins: from molecular circuits to dynamic self-stabilizing cell polarity. Development 2017; 144:3405-3416. [PMID: 28974638 DOI: 10.1242/dev.139063] [Citation(s) in RCA: 88] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
PAR proteins constitute a highly conserved network of scaffolding proteins, adaptors and enzymes that form and stabilize cortical asymmetries in response to diverse inputs. They function throughout development and across the metazoa to regulate cell polarity. In recent years, traditional approaches to identifying and characterizing molecular players and interactions in the PAR network have begun to merge with biophysical, theoretical and computational efforts to understand the network as a pattern-forming biochemical circuit. Here, we summarize recent progress in the field, focusing on recent studies that have characterized the core molecular circuitry, circuit design and spatiotemporal dynamics. We also consider some of the ways in which the PAR network has evolved to polarize cells in different contexts and in response to different cues and functional constraints.
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Affiliation(s)
- Charles F Lang
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL 60637, USA.,Committee on Genetics, Genomics and Systems Biology, University of Chicago, Chicago, IL 60637, USA
| | - Edwin Munro
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL 60637, USA .,Committee on Genetics, Genomics and Systems Biology, University of Chicago, Chicago, IL 60637, USA
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86
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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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87
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Zihni C, Vlassaks E, Terry S, Carlton J, Leung TKC, Olson M, Pichaud F, Balda MS, Matter K. An apical MRCK-driven morphogenetic pathway controls epithelial polarity. Nat Cell Biol 2017; 19:1049-1060. [PMID: 28825699 PMCID: PMC5617103 DOI: 10.1038/ncb3592] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Accepted: 07/17/2017] [Indexed: 12/13/2022]
Abstract
Polarized epithelia develop distinct cell surface domains, with the apical membrane acquiring characteristic morphological features such as microvilli. Cell polarization is driven by polarity determinants including the evolutionarily conserved partitioning-defective (PAR) proteins that are separated into distinct cortical domains. PAR protein segregation is thought to be a consequence of asymmetric actomyosin contractions. The mechanism of activation of apically polarized actomyosin contractility is unknown. Here we show that the Cdc42 effector MRCK activates myosin-II at the apical pole to segregate aPKC-Par6 from junctional Par3, defining the apical domain. Apically polarized MRCK-activated actomyosin contractility is reinforced by cooperation with aPKC-Par6 downregulating antagonistic RhoA-driven junctional actomyosin contractility, and drives polarization of cytosolic brush border determinants and apical morphogenesis. MRCK-activated polarized actomyosin contractility is required for apical differentiation and morphogenesis in vertebrate epithelia and Drosophila photoreceptors. Our results identify an apical origin of actomyosin-driven morphogenesis that couples cytoskeletal reorganization to PAR polarity signalling.
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Affiliation(s)
- Ceniz Zihni
- Institute of Ophthalmology, University College London, Bath Street, London EC1V 9EL, UK
| | - Evi Vlassaks
- MRC Laboratory for Molecular Cell Biology, University College London, Gower Street, London WC1E 6BT, UK
| | - Stephen Terry
- Institute of Ophthalmology, University College London, Bath Street, London EC1V 9EL, UK
| | - Jeremy Carlton
- Division of Cancer Studies, Section of Cell Biology and Imaging, King's College London, London SE1 1UL, UK
| | - Thomas King Chor Leung
- Institute of Molecular and Cell Biology, A-STAR, 61 Biopolis Drive, Singapore 138673 and the Department of Anatomy, National University of Singapore, Singapore 119260, Singapore
| | - Michael Olson
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK
| | - Franck Pichaud
- MRC Laboratory for Molecular Cell Biology, University College London, Gower Street, London WC1E 6BT, UK
| | - Maria Susana Balda
- Institute of Ophthalmology, University College London, Bath Street, London EC1V 9EL, UK
| | - Karl Matter
- Institute of Ophthalmology, University College London, Bath Street, London EC1V 9EL, UK
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88
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Abstract
The scaffold protein Par-3 (
Drosophila Bazooka) is a central organizer of cell polarity across animals. This review focuses on how the clustering of Par-3 contributes to cell polarity. It begins with the Par-3 homo-oligomerization mechanism and its regulation by Par-1 phosphorylation. The role of polarized cytoskeletal networks in distributing Par-3 clusters to one end of the cell is then discussed, as is the subsequent maintenance of polarized Par-3 clusters through hindered mobility and inhibition from the opposite pole. Finally, specific roles of Par-3 clusters are reviewed, including the bundling of microtubules, the cortical docking of centrosomes, the growth and positioning of cadherin–catenin clusters, and the inhibition of the Par-6–aPKC kinase cassette. Examples are drawn from
Drosophila, Caenorhabditis elegans, mammalian cell culture, and biochemical studies.
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Affiliation(s)
- Tony J C Harris
- Department of Cell & Systems Biology, University of Toronto, Toronto, Canada
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89
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Rodriguez J, Peglion F, Martin J, Hubatsch L, Reich J, Hirani N, Gubieda AG, Roffey J, Fernandes AR, St Johnston D, Ahringer J, Goehring NW. aPKC Cycles between Functionally Distinct PAR Protein Assemblies to Drive Cell Polarity. Dev Cell 2017; 42:400-415.e9. [PMID: 28781174 PMCID: PMC5563072 DOI: 10.1016/j.devcel.2017.07.007] [Citation(s) in RCA: 105] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Revised: 06/19/2017] [Accepted: 07/10/2017] [Indexed: 01/09/2023]
Abstract
The conserved polarity effector proteins PAR-3, PAR-6, CDC-42, and atypical protein kinase C (aPKC) form a core unit of the PAR protein network, which plays a central role in polarizing a broad range of animal cell types. To functionally polarize cells, these proteins must activate aPKC within a spatially defined membrane domain on one side of the cell in response to symmetry-breaking cues. Using the Caenorhabditis elegans zygote as a model, we find that the localization and activation of aPKC involve distinct, specialized aPKC-containing assemblies: a PAR-3-dependent assembly that responds to polarity cues and promotes efficient segregation of aPKC toward the anterior but holds aPKC in an inactive state, and a CDC-42-dependent assembly in which aPKC is active but poorly segregated. Cycling of aPKC between these distinct functional assemblies, which appears to depend on aPKC activity, effectively links cue-sensing and effector roles within the PAR network to ensure robust establishment of polarity.
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Affiliation(s)
- Josana Rodriguez
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK; Wellcome Trust/Cancer Research UK Gurdon Institute, Cambridge CB2 1QN, UK.
| | | | - Jack Martin
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | | | - Jacob Reich
- The Francis Crick Institute, London NW1 1AT, UK
| | | | - Alicia G Gubieda
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Jon Roffey
- Cancer Research Technology, Wolfson Institute for Biomedical Research, London WC1E 6BT, UK
| | | | - Daniel St Johnston
- Wellcome Trust/Cancer Research UK Gurdon Institute, Cambridge CB2 1QN, UK
| | - Julie Ahringer
- Wellcome Trust/Cancer Research UK Gurdon Institute, Cambridge CB2 1QN, UK
| | - Nathan W Goehring
- The Francis Crick Institute, London NW1 1AT, UK; Medical Research Council Laboratory for Molecular Cell Biology, University College London, London WC1E 6BT, UK.
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90
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Ebnet K, Kummer D, Steinbacher T, Singh A, Nakayama M, Matis M. Regulation of cell polarity by cell adhesion receptors. Semin Cell Dev Biol 2017; 81:2-12. [PMID: 28739340 DOI: 10.1016/j.semcdb.2017.07.032] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 07/12/2017] [Accepted: 07/20/2017] [Indexed: 01/01/2023]
Abstract
The ability of cells to polarize is an intrinsic property of almost all cells and is required for the devlopment of most multicellular organisms. To develop cell polarity, cells integrate various signals derived from intrinsic as well as extrinsic sources. In the recent years, cell-cell adhesion receptors have turned out as important regulators of cellular polarization. By interacting with conserved cell polarity proteins, they regulate the recruitment of polarity complexes to specific sites of cell-cell adhesion. By initiating intracellular signaling cascades at those sites, they trigger their specific subcellular activation. Not surprisingly, cell-cell adhesion receptors regulate diverse aspects of cell polarity, including apico-basal polarity in epithelial and endothelial cells, front-to-rear polarity in collectively migrating cells, and planar cell polarity during organ development. Here, we review the recent developments highlighting the central roles of cell-cell adhesion molecules in the development of cell polarity.
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Affiliation(s)
- Klaus Ebnet
- Institute-associated Research Group: Cell adhesion and cell polarity, Institute of Medical Biochemistry, ZMBE, University of Münster, Germany; Interdisciplinary Clinical Research Center (IZKF), University of Münster, Germany; Cells-In-Motion Cluster of Excellence (EXC1003-CiM), University of Münster, Germany.
| | - Daniel Kummer
- Institute-associated Research Group: Cell adhesion and cell polarity, Institute of Medical Biochemistry, ZMBE, University of Münster, Germany; Interdisciplinary Clinical Research Center (IZKF), University of Münster, Germany
| | - Tim Steinbacher
- Institute-associated Research Group: Cell adhesion and cell polarity, Institute of Medical Biochemistry, ZMBE, University of Münster, Germany; Cells-In-Motion Cluster of Excellence (EXC1003-CiM), University of Münster, Germany
| | - Amrita Singh
- Cells-In-Motion Cluster of Excellence (EXC1003-CiM), University of Münster, Germany; Institute of Cell Biology, ZMBE, University of Münster, Germany
| | - Masanori Nakayama
- Laboratory for Cell Polarity and Organogenesis, Max-Planck-Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Maja Matis
- Cells-In-Motion Cluster of Excellence (EXC1003-CiM), University of Münster, Germany; Institute of Cell Biology, ZMBE, University of Münster, Germany.
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91
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Feng Q, Bonder EM, Engevik AC, Zhang L, Tyska MJ, Goldenring JR, Gao N. Disruption of Rab8a and Rab11a causes formation of basolateral microvilli in neonatal enteropathy. J Cell Sci 2017; 130:2491-2505. [PMID: 28596241 DOI: 10.1242/jcs.201897] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Accepted: 06/01/2017] [Indexed: 12/15/2022] Open
Abstract
Misplaced formation of microvilli to basolateral domains and intracellular inclusions in enterocytes are pathognomonic features in congenital enteropathy associated with mutation of the apical plasma membrane receptor syntaxin 3 (STX3). Although the demonstrated binding of Myo5b to the Rab8a and Rab11a small GTPases in vitro implicates cytoskeleton-dependent membrane sorting, the mechanisms underlying the microvillar location defect remain unclear. By selective or combinatory disruption of Rab8a and Rab11a membrane traffic in vivo, we demonstrate that transport of distinct cargo to the apical brush border rely on either individual or both Rab regulators, whereas certain basolateral cargos are redundantly transported by both factors. Enterocyte-specific Rab8a and Rab11a double-knockout mouse neonates showed immediate postnatal lethality and more severe enteropathy than single knockouts, with extensive formation of microvilli along basolateral surfaces. Notably, following an inducible Rab11a deletion from neonatal enterocytes, basolateral microvilli were induced within 3 days. These data identify a potentially important and distinct mechanism for a characteristic microvillus defect exhibited by enterocytes of patients with neonatal enteropathy.
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Affiliation(s)
- Qiang Feng
- Department of Biological Sciences, Rutgers University, Newark, NJ 07102, USA
| | - Edward M Bonder
- Department of Biological Sciences, Rutgers University, Newark, NJ 07102, USA
| | - Amy C Engevik
- Department of Surgery, and Epithelial Biology Center, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Lanjing Zhang
- Department of Biological Sciences, Rutgers University, Newark, NJ 07102, USA.,Department of Pathology, University Medical Center of Princeton, Plainsboro, NJ 08536, USA.,Rutgers Cancer Institute of New Jersey, Rutgers University, Piscataway, NJ 08903, USA
| | - Matthew J Tyska
- Department of Cell & Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - James R Goldenring
- Department of Surgery, and Epithelial Biology Center, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.,Department of Cell & Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.,Nashville VA Medical Center, Vanderbilt University, Nashville, TN 37232, USA
| | - Nan Gao
- Department of Biological Sciences, Rutgers University, Newark, NJ 07102, USA .,Rutgers Cancer Institute of New Jersey, Rutgers University, Piscataway, NJ 08903, USA
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92
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Ruch TR, Engel JN. Targeting the Mucosal Barrier: How Pathogens Modulate the Cellular Polarity Network. Cold Spring Harb Perspect Biol 2017; 9:cshperspect.a027953. [PMID: 28193722 DOI: 10.1101/cshperspect.a027953] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The mucosal barrier is composed of polarized epithelial cells with distinct apical and basolateral surfaces separated by tight junctions and serves as both a physical and immunological barrier to incoming pathogens. Specialized polarity proteins are critical for establishment and maintenance of polarity. Many human pathogens have evolved virulence mechanisms that target the polarity network to enhance binding, create replication niches, move through the barrier by transcytosis, or bypass the barrier by disrupting cell-cell junctions. This review summarizes recent advances and compares and contrasts how three important human pathogens that colonize mucosal surfaces, Pseudomonas aeruginosa, Helicobacter pylori, and Neisseria meningitidis, subvert the host cell polarization machinery during infection.
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Affiliation(s)
- Travis R Ruch
- Department of Medicine, University of California, San Francisco, San Francisco, California 94143
| | - Joanne N Engel
- Department of Medicine, University of California, San Francisco, San Francisco, California 94143.,Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, California 94143
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93
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Thieleke-Matos C, Osório DS, Carvalho AX, Morais-de-Sá E. Emerging Mechanisms and Roles for Asymmetric Cytokinesis. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2017; 332:297-345. [PMID: 28526136 DOI: 10.1016/bs.ircmb.2017.01.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Cytokinesis completes cell division by physically separating the contents of the mother cell between the two daughter cells. This event requires the highly coordinated reorganization of the cytoskeleton within a precise window of time to ensure faithful genomic segregation. In addition, recent progress in the field highlighted the importance of cytokinesis in providing particularly important cues in the context of multicellular tissues. The organization of the cytokinetic machinery and the asymmetric localization or inheritance of the midbody remnants is critical to define the spatial distribution of mechanical and biochemical signals. After a brief overview of the conserved steps of animal cytokinesis, we review the mechanisms controlling polarized cytokinesis focusing on the challenges of epithelial cytokinesis. Finally, we discuss the significance of these asymmetries in defining embryonic body axes, determining cell fate, and ensuring the correct propagation of epithelial organization during proliferation.
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Affiliation(s)
- C Thieleke-Matos
- i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal; Cell Division and Genomic stability, IBMC, Instituto de Biologia Molecular e Celular, and i3S, Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
| | - D S Osório
- i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal; Cytoskeletal Dynamics, IBMC, Instituto de Biologia Molecular e Celular, and i3S, Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
| | - A X Carvalho
- i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal; Cytoskeletal Dynamics, IBMC, Instituto de Biologia Molecular e Celular, and i3S, Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
| | - E Morais-de-Sá
- i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal; Cell Division and Genomic stability, IBMC, Instituto de Biologia Molecular e Celular, and i3S, Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.
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94
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Kong D, Wolf F, Großhans J. Forces directing germ-band extension in Drosophila embryos. Mech Dev 2016; 144:11-22. [PMID: 28013027 DOI: 10.1016/j.mod.2016.12.001] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2016] [Revised: 12/12/2016] [Accepted: 12/13/2016] [Indexed: 01/06/2023]
Abstract
Body axis elongation by convergent extension is a conserved developmental process found in all metazoans. Drosophila embryonic germ-band extension is an important morphogenetic process during embryogenesis, by which the length of the germ-band is more than doubled along the anterior-posterior axis. This lengthening is achieved by typical convergent extension, i.e. narrowing the lateral epidermis along the dorsal-ventral axis and simultaneous extension along the anterior-posterior axis. Germ-band extension is largely driven by cell intercalation, whose directionality is determined by the planar polarity of the tissue and ultimately by the anterior-posterior patterning system. In addition, extrinsic tensile forces originating from the invaginating endoderm induce cell shape changes, which transiently contribute to germ-band extension. Here, we review recent progress in understanding of the role of mechanical forces in germ-band extension.
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Affiliation(s)
- Deqing Kong
- Institute for Developmental Biochemistry, Medical School, University of Göttingen, Justus-von-Liebig Weg 11, 37077 Göttingen, Germany
| | - Fred Wolf
- Department of Nonlinear Dynamics, Max Planck Institute for Dynamics and Self-Organisation, Faculty of Physics, Bernstein Center for Computational Neuroscience, University of Göttingen, Am Faßberg 17, 37077 Göttingen, Germany
| | - Jörg Großhans
- Institute for Developmental Biochemistry, Medical School, University of Göttingen, Justus-von-Liebig Weg 11, 37077 Göttingen, Germany.
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95
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Ruch TR, Bryant DM, Mostov KE, Engel JN. Par3 integrates Tiam1 and phosphatidylinositol 3-kinase signaling to change apical membrane identity. Mol Biol Cell 2016; 28:252-260. [PMID: 27881661 PMCID: PMC5231894 DOI: 10.1091/mbc.e16-07-0541] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Revised: 11/16/2016] [Accepted: 11/18/2016] [Indexed: 01/31/2023] Open
Abstract
Pathogens can alter epithelial polarity by recruiting polarity proteins to the apical membrane, but how a change in protein localization is linked to polarity disruption is not clear. In this study, we used chemically induced dimerization to rapidly relocalize proteins from the cytosol to the apical surface. We demonstrate that forced apical localization of Par3, which is normally restricted to tight junctions, is sufficient to alter apical membrane identity through its interactions with phosphatidylinositol 3-kinase (PI3K) and the Rac1 guanine nucleotide exchange factor Tiam1. We further show that PI3K activity is required upstream of Rac1, and that simultaneously targeting PI3K and Tiam1 to the apical membrane has a synergistic effect on membrane remodeling. Thus, Par3 coordinates the action of PI3K and Tiam1 to define membrane identity, revealing a signaling mechanism that can be exploited by human mucosal pathogens.
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Affiliation(s)
- Travis R Ruch
- Department of Medicine, University of California, San Francisco, San Francisco, CA 94143
| | - David M Bryant
- Department of Anatomy, University of California, San Francisco, San Francisco, CA 94158.,Cancer Research UK Beatson Institute, University of Glasgow, Glasgow G61 1BD, United Kingdom.,Institute of Cancer Sciences, University of Glasgow, Glasgow G61 1BD, United Kingdom
| | - Keith E Mostov
- Department of Anatomy, University of California, San Francisco, San Francisco, CA 94158.,Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94158
| | - Joanne N Engel
- Department of Medicine, University of California, San Francisco, San Francisco, CA 94143
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96
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Xiong X, Li X, Wen YA, Gao T. Pleckstrin Homology (PH) Domain Leucine-rich Repeat Protein Phosphatase Controls Cell Polarity by Negatively Regulating the Activity of Atypical Protein Kinase C. J Biol Chem 2016; 291:25167-25178. [PMID: 27760826 DOI: 10.1074/jbc.m116.740639] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Revised: 10/18/2016] [Indexed: 02/04/2023] Open
Abstract
The proper establishment of epithelial polarity allows cells to sense and respond to signals that arise from the microenvironment in a spatiotemporally controlled manner. Atypical PKCs (aPKCs) are implicated as key regulators of epithelial polarity. However, the molecular mechanism underlying the negative regulation of aPKCs remains largely unknown. In this study, we demonstrated that PH domain leucine-rich repeat protein phosphatase (PHLPP), a novel family of Ser/Thr protein phosphatases, plays an important role in regulating epithelial polarity by controlling the phosphorylation of both aPKC isoforms. Altered expression of PHLPP1 or PHLPP2 disrupted polarization of Caco2 cells grown in 3D cell cultures as indicated by the formation of aberrant multi-lumen structures. Overexpression of PHLPP resulted in a decrease in aPKC phosphorylation at both the activation loop and the turn motif sites; conversely, knockdown of PHLPP increased aPKC phosphorylation. Moreover, in vitro dephosphorylation experiments revealed that both aPKC isoforms were substrates of PHLPP. Interestingly, knockdown of PKCζ, but not PKCι, led to similar disruption of the polarized lumen structure, suggesting that PKCζ likely controls the polarization process of Caco2 cells. Furthermore, knockdown of PHLPP altered the apical membrane localization of aPKCs and reduced the formation of aPKC-Par3 complex. Taken together, our results identify a novel role of PHLPP in regulating aPKC and cell polarity.
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Affiliation(s)
| | - Xin Li
- From the Markey Cancer Center and
| | | | - Tianyan Gao
- From the Markey Cancer Center and .,Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, Kentucky 40536-0509
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97
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Visco I, Hoege C, Hyman AA, Schwille P. In vitro Reconstitution of a Membrane Switch Mechanism for the Polarity Protein LGL. J Mol Biol 2016; 428:4828-4842. [PMID: 27720986 DOI: 10.1016/j.jmb.2016.10.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Revised: 09/28/2016] [Accepted: 10/01/2016] [Indexed: 12/24/2022]
Abstract
Cell polarity arises from a combination of interactions between biological molecules, such as activation, inhibition, and positive or negative feedback between specific polarity units. Activation and inhibition often take place in the form of a membrane binding switch. Lethal giant larvae (LGL), a conserved regulator of cell polarity in animals, was suggested to function as such a switch. LGL localizes to both the cytoplasm and, asymmetrically, the membrane. However, the spatial regulation mechanism of LGL membrane localization has remained unclear. For systematic elucidation, we set out to reconstitute a minimal polarity unit using a model membrane, Caenorhabditis elegans LGL (LGL-1), and atypical protein kinase C (aPKC) supposed to activate the membrane switch. We identified a membrane binding sequence (MBS) in LGL-1 by a screen in vivo, reconstituted LGL-1 membrane binding in vitro, and successfully implemented the membrane switch by aPKC phosphorylation activity, detaching LGL from membranes. Upon membrane binding, LGL-1 MBS folds into an alpha-helix in which three regions can be identified: a positively charged patch, a switch area containing the three aPKC phosphorylation sites, and a hydrophobic area probably buried in the membrane. Phosphorylation by aPKC dramatically reduces the binding affinity of the LGL-1 MBS to negatively charged model membranes, inducing its detachment. Specific residues in the MBS are critical for LGL-1 function in C. elegans.
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Affiliation(s)
- Ilaria Visco
- Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany.
| | - Carsten Hoege
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany
| | - Anthony A Hyman
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany
| | - Petra Schwille
- Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany.
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98
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Flores-Benitez D, Knust E. Dynamics of epithelial cell polarity in Drosophila: how to regulate the regulators? Curr Opin Cell Biol 2016; 42:13-21. [DOI: 10.1016/j.ceb.2016.03.018] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Accepted: 03/25/2016] [Indexed: 10/22/2022]
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99
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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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100
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Coopman P, Djiane A. Adherens Junction and E-Cadherin complex regulation by epithelial polarity. Cell Mol Life Sci 2016; 73:3535-53. [PMID: 27151512 PMCID: PMC11108514 DOI: 10.1007/s00018-016-2260-8] [Citation(s) in RCA: 105] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Revised: 04/28/2016] [Accepted: 04/29/2016] [Indexed: 12/29/2022]
Abstract
E-Cadherin-based Adherens Junctions (AJs) are a defining feature of all epithelial sheets. Through the homophilic association of E-Cadherin molecules expressed on neighboring cells, they ensure intercellular adhesion amongst epithelial cells, and regulate many key aspects of epithelial biology. While their adhesive role requires these structures to remain stable, AJs are also extremely plastic. This plasticity allows for the adaptation of the cell to its changing environment: changes in neighbors after cell division, cell death, or cell movement, and changes in cell shape during differentiation. In this review we focus on the recent advances highlighting the critical role of the apico-basal polarity machinery, and in particular of the Par3/Bazooka scaffold, in the regulation and remodeling of AJs. We propose that by regulating key phosphorylation events on the core E-Cadherin complex components, Par3 and epithelial polarity promote meta-stable protein complexes governing the correct formation, localization, and functioning of AJ.
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Affiliation(s)
- Peter Coopman
- IRCM, Institut de Recherche en Cancérologie de Montpellier, Montpellier, F-34298, France
- IRCM, INSERM U1194, Montpellier, F-34298, France
- Université de Montpellier, Montpellier, F-34090, France
- Institut régional du Cancer de Montpellier, Montpellier, F-34298, France
| | - Alexandre Djiane
- IRCM, Institut de Recherche en Cancérologie de Montpellier, Montpellier, F-34298, France.
- IRCM, INSERM U1194, Montpellier, F-34298, France.
- Université de Montpellier, Montpellier, F-34090, France.
- Institut régional du Cancer de Montpellier, Montpellier, F-34298, France.
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