1
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Abrams J, Nance J. A polarity pathway for exocyst-dependent intracellular tube extension. eLife 2021; 10:65169. [PMID: 33687331 PMCID: PMC8021397 DOI: 10.7554/elife.65169] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 03/08/2021] [Indexed: 12/25/2022] Open
Abstract
Lumen extension in intracellular tubes can occur when vesicles fuse with an invading apical membrane. Within the Caenorhabditis elegans excretory cell, which forms an intracellular tube, the exocyst vesicle-tethering complex is enriched at the lumenal membrane and is required for its outgrowth, suggesting that exocyst-targeted vesicles extend the lumen. Here, we identify a pathway that promotes intracellular tube extension by enriching the exocyst at the lumenal membrane. We show that PAR-6 and PKC-3/aPKC concentrate at the lumenal membrane and promote lumen extension. Using acute protein depletion, we find that PAR-6 is required for exocyst membrane recruitment, whereas PAR-3, which can recruit the exocyst in mammals, appears dispensable for exocyst localization and lumen extension. Finally, we show that CDC-42 and RhoGEF EXC-5/FGD regulate lumen extension by recruiting PAR-6 and PKC-3 to the lumenal membrane. Our findings reveal a pathway that connects CDC-42, PAR proteins, and the exocyst to extend intracellular tubes.
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Affiliation(s)
- Joshua Abrams
- Skirball Institute of Biomolecular Medicine, NYU Grossman School of Medicine, New York, United States
| | - Jeremy Nance
- Skirball Institute of Biomolecular Medicine, NYU Grossman School of Medicine, New York, United States.,Department of Cell Biology, NYU Grossman School of Medicine, New York, United States
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2
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Abstract
As multi-cellular organisms evolved from small clusters of cells to complex metazoans, biological tubes became essential for life. Tubes are typically thought of as mainly playing a role in transport, with the hollow space (lumen) acting as a conduit to distribute nutrients and waste, or for gas exchange. However, biological tubes also provide a platform for physiological, mechanical, and structural functions. Indeed, tubulogenesis is often a critical aspect of morphogenesis and organogenesis. C. elegans is made up of tubes that provide structural support and protection (the epidermis), perform the mechanical and enzymatic processes of digestion (the buccal cavity, pharynx, intestine, and rectum), transport fluids for osmoregulation (the excretory system), and execute the functions necessary for reproduction (the germline, spermatheca, uterus and vulva). Here we review our current understanding of the genetic regulation, molecular processes, and physical forces involved in tubulogenesis and morphogenesis of the epidermal, digestive and excretory systems in C. elegans.
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Affiliation(s)
- Daniel D Shaye
- Department of Physiology and Biophysics, University of Illinois at Chicago-College of Medicine, Chicago, IL, United States.
| | - Martha C Soto
- Department of Pathology and Laboratory Medicine, Rutgers-Robert Wood Johnson Medical School, Piscataway, NJ, United States.
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3
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Yang Z, Mattingly BC, Hall DH, Ackley BD, Buechner M. Terminal web and vesicle trafficking proteins mediate nematode single-cell tubulogenesis. J Cell Biol 2020; 219:e202003152. [PMID: 32860501 PMCID: PMC7594493 DOI: 10.1083/jcb.202003152] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 06/15/2020] [Accepted: 08/03/2020] [Indexed: 11/22/2022] Open
Abstract
Single-celled tubules represent a complicated structure that forms during development, requiring extension of a narrow cytoplasm surrounding a lumen exerting osmotic pressure that can burst the luminal membrane. Genetic studies on the excretory canal cell of Caenorhabditis elegans have revealed many proteins that regulate the cytoskeleton, vesicular transport, and physiology of the narrow canals. Here, we show that βH-spectrin regulates the placement of intermediate filament proteins forming a terminal web around the lumen, and that the terminal web in turn retains a highly conserved protein (EXC-9/CRIP1) that regulates apical endosomal trafficking. EXC-1/IRG, the binding partner of EXC-9, is also localized to the apical membrane and affects apical actin placement and RAB-8-mediated vesicular transport. The results suggest that an intermediate filament protein acts in a novel pathway to direct the traffic of vesicles to locations of lengthening apical surface during single-celled tubule development.
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Affiliation(s)
- Zhe Yang
- Department of Molecular Biosciences, University of Kansas, Lawrence, KS
| | | | - David H. Hall
- Center for C. elegans Anatomy, Albert Einstein College of Medicine, Bronx, NY
| | - Brian D. Ackley
- Department of Molecular Biosciences, University of Kansas, Lawrence, KS
| | - Matthew Buechner
- Department of Molecular Biosciences, University of Kansas, Lawrence, KS
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4
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Chung KW, Kim JS, Lee KS. A Database of Caenorhabditis elegans Locomotion and Body Posture Phenotypes for the Peripheral Neuropathy Model. Mol Cells 2020; 43:880-888. [PMID: 33115980 PMCID: PMC7604027 DOI: 10.14348/molcells.2020.0178] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 10/06/2020] [Accepted: 10/07/2020] [Indexed: 12/17/2022] Open
Abstract
Inherited peripheral neuropathy is a heterogeneous group of peripheral neurodegenerative disorders including Charcot-Marie-Tooth disease. Many peripheral neuropathies often accompany impaired axonal construction and function. To study the molecular and cellular basis of axon-defective peripheral neuropathy, we explore the possibility of using Caenorhabditis elegans, a powerful nematode model equipped with a variety of genetics and imaging tools. In search of potential candidates of C. elegans peripheral neuropathy models, we monitored the movement and the body posture patterns of 26 C. elegans strains with disruption of genes associated with various peripheral neuropathies and compiled a database of their phenotypes. Our assay showed that movement features of the worms with mutations in HSPB1, MFN2, DYNC1H1, and KIF1B human homologues are significantly different from the control strain, suggesting they are viable candidates for C. elegans peripheral neuropathy models.
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Affiliation(s)
- Ki Wha Chung
- Department of Biological Sciences, Kongju National University, Gongju 32588, Korea
| | - Ju Seong Kim
- Department of Biological Sciences, Kongju National University, Gongju 32588, Korea
| | - Kyung Suk Lee
- Department of Physics Education, Kongju National University, Gongju 32588, Korea
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5
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Buechner M, Yang Z, Al-Hashimi H. A Series of Tubes: The C. elegans Excretory Canal Cell as a Model for Tubule Development. J Dev Biol 2020; 8:jdb8030017. [PMID: 32906663 PMCID: PMC7557474 DOI: 10.3390/jdb8030017] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 08/31/2020] [Accepted: 09/02/2020] [Indexed: 12/25/2022] Open
Abstract
Formation and regulation of properly sized epithelial tubes is essential for multicellular life. The excretory canal cell of C. elegans provides a powerful model for investigating the integration of the cytoskeleton, intracellular transport, and organismal physiology to regulate the developmental processes of tube extension, lumen formation, and lumen diameter regulation in a narrow single cell. Multiple studies have provided new understanding of actin and intermediate filament cytoskeletal elements, vesicle transport, and the role of vacuolar ATPase in determining tube size. Most of the genes discovered have clear homologues in humans, with implications for understanding these processes in mammalian tissues such as Schwann cells, renal tubules, and brain vasculature. The results of several new genetic screens are described that provide a host of new targets for future studies in this informative structure.
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Affiliation(s)
- Matthew Buechner
- Department of Molecular Biosciences, University of Kansas, Lawrence, KS 66045, USA;
- Correspondence:
| | - Zhe Yang
- Department of Molecular Biosciences, University of Kansas, Lawrence, KS 66045, USA;
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6
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Lant B, Pal S, Chapman EM, Yu B, Witvliet D, Choi S, Zhao L, Albiges-Rizo C, Faurobert E, Derry WB. Interrogating the ccm-3 Gene Network. Cell Rep 2019; 24:2857-2868.e4. [PMID: 30208312 DOI: 10.1016/j.celrep.2018.08.039] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Revised: 06/27/2018] [Accepted: 08/15/2018] [Indexed: 01/29/2023] Open
Abstract
Cerebral cavernous malformations (CCMs) are neurovascular lesions caused by mutations in one of three genes (CCM1-3). Loss of CCM3 causes the poorest prognosis, and little is known about how it regulates vascular integrity. The C. elegans ccm-3 gene regulates the development of biological tubes that resemble mammalian vasculature, and in a genome-wide reverse genetic screen, we identified more than 500 possible CCM-3 pathway genes. With a phenolog-like approach, we generated a human CCM signaling network and identified 29 genes in common, of which 14 are required for excretory canal extension and membrane integrity, similar to ccm-3. Notably, depletion of the MO25 ortholog mop-25.2 causes severe defects in tube integrity by preventing CCM-3 localization to apical membranes. Furthermore, loss of MO25 phenocopies CCM3 ablation by causing stress fiber formation in endothelial cells. This work deepens our understanding of how CCM3 regulates vascular integrity and may help identify therapeutic targets for treating CCM3 patients.
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Affiliation(s)
- Benjamin Lant
- Developmental and Stem Cell Biology Program, The Hospital for Sick Children, Peter Gilgan Centre for Research and Learning, 686 Bay Street, Toronto, ON M5G 0A4, Canada
| | - Swati Pal
- Developmental and Stem Cell Biology Program, The Hospital for Sick Children, Peter Gilgan Centre for Research and Learning, 686 Bay Street, Toronto, ON M5G 0A4, Canada
| | - Eric Michael Chapman
- Developmental and Stem Cell Biology Program, The Hospital for Sick Children, Peter Gilgan Centre for Research and Learning, 686 Bay Street, Toronto, ON M5G 0A4, Canada; Department of Molecular Genetics, University of Toronto, 1 King's College Circle, Toronto, ON M5S 1A8, Canada
| | - Bin Yu
- Developmental and Stem Cell Biology Program, The Hospital for Sick Children, Peter Gilgan Centre for Research and Learning, 686 Bay Street, Toronto, ON M5G 0A4, Canada
| | - Daniel Witvliet
- Department of Molecular Genetics, University of Toronto, 1 King's College Circle, Toronto, ON M5S 1A8, Canada; Lunenfeld-Tanenbaum Research Institute at Mount Sinai Hospital, 600 University Avenue, Toronto, ON M5G 1X5, Canada
| | - Soo Choi
- Developmental and Stem Cell Biology Program, The Hospital for Sick Children, Peter Gilgan Centre for Research and Learning, 686 Bay Street, Toronto, ON M5G 0A4, Canada
| | - Lisa Zhao
- Department of Molecular Genetics, University of Toronto, 1 King's College Circle, Toronto, ON M5S 1A8, Canada
| | - Corinne Albiges-Rizo
- Institute for Advanced Biosciences, CNRS UMR 5309, INSERM U1209, University Grenoble Alpes, Allée des Alpes, 38700 La Tronche, France
| | - Eva Faurobert
- Institute for Advanced Biosciences, CNRS UMR 5309, INSERM U1209, University Grenoble Alpes, Allée des Alpes, 38700 La Tronche, France
| | - W Brent Derry
- Developmental and Stem Cell Biology Program, The Hospital for Sick Children, Peter Gilgan Centre for Research and Learning, 686 Bay Street, Toronto, ON M5G 0A4, Canada; Department of Molecular Genetics, University of Toronto, 1 King's College Circle, Toronto, ON M5S 1A8, Canada.
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7
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Khan LA, Jafari G, Zhang N, Membreno E, Yan S, Zhang H, Gobel V. A tensile trilayered cytoskeletal endotube drives capillary-like lumenogenesis. J Cell Biol 2019; 218:2403-2424. [PMID: 31239283 PMCID: PMC6605810 DOI: 10.1083/jcb.201811175] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2018] [Revised: 04/09/2019] [Accepted: 05/14/2019] [Indexed: 01/01/2023] Open
Abstract
Unicellular tubes are components of internal organs and capillaries. It is unclear how they meet the architectural challenge to extend a centered intracellular lumen of uniform diameter. In an RNAi-based Caenorhabditis elegans screen, we identified three intermediate filaments (IFs)-IFA-4, IFB-1, and IFC-2-as interactors of the lumenal membrane-actin linker ERM-1 in excretory-canal tubulogenesis. We find that IFs, generally thought to affect morphogenesis indirectly by maintaining tissue integrity, directly promote lumenogenesis in this capillary-like single-cell tube. We show that ERM-1, ACT-5/actin, and TBB-2/tubulin recruit membrane-forming endosomal and flux-promoting canalicular vesicles to the lumen, whereas IFs, themselves recruited to the lumen by ERM-1 and TBB-2, restrain lateral vesicle access. IFs thereby prevent cystogenesis, equilibrate the lumen diameter, and promote lumen forward extension. Genetic and imaging analyses suggest that IFB-1/IFA-4 and IFB-1/IFC-2 polymers form a perilumenal triple IF lattice, sandwiched between actin and helical tubulin. Our findings characterize a novel mechanism of capillary-like lumenogenesis, where a tensile trilayered cytoskeletal endotube transforms concentric into directional growth.
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Affiliation(s)
- Liakot A Khan
- Mucosal Immunology and Biology Research Center, Developmental Biology and Genetics Core, Massachusetts General Hospital for Children, Harvard Medical School, Boston, MA
| | - Gholamali Jafari
- Mucosal Immunology and Biology Research Center, Developmental Biology and Genetics Core, Massachusetts General Hospital for Children, Harvard Medical School, Boston, MA
| | - Nan Zhang
- Mucosal Immunology and Biology Research Center, Developmental Biology and Genetics Core, Massachusetts General Hospital for Children, Harvard Medical School, Boston, MA
- Key Laboratory of Zoonosis Research, Institute of Zoonosis, College of Veterinary Medicine, Jilin University, Changchun, China
| | - Edward Membreno
- Mucosal Immunology and Biology Research Center, Developmental Biology and Genetics Core, Massachusetts General Hospital for Children, Harvard Medical School, Boston, MA
| | - Siyang Yan
- Mucosal Immunology and Biology Research Center, Developmental Biology and Genetics Core, Massachusetts General Hospital for Children, Harvard Medical School, Boston, MA
| | - Hongjie Zhang
- Mucosal Immunology and Biology Research Center, Developmental Biology and Genetics Core, Massachusetts General Hospital for Children, Harvard Medical School, Boston, MA
- Faculty of Health Sciences, University of Macau, Taipa, Macau, China
| | - Verena Gobel
- Mucosal Immunology and Biology Research Center, Developmental Biology and Genetics Core, Massachusetts General Hospital for Children, Harvard Medical School, Boston, MA
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8
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Novel exc Genes Involved in Formation of the Tubular Excretory Canals of Caenorhabditis elegans. G3-GENES GENOMES GENETICS 2019; 9:1339-1353. [PMID: 30885922 PMCID: PMC6505153 DOI: 10.1534/g3.119.200626] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Regulation of luminal diameter is critical to the function of small single-celled tubes, of which the seamless tubular excretory canals of Caenorhabditis elegans provide a tractable genetic model. Mutations in several sets of genes exhibit the Exc phenotype, in which canal luminal growth is visibly altered. Here, a focused reverse genomic screen of genes highly expressed in the canals found 18 genes that significantly affect luminal outgrowth or diameter. These genes encode novel proteins as well as highly conserved proteins involved in processes including gene expression, cytoskeletal regulation, and vesicular and transmembrane transport. In addition, two genes act as suppressors on a pathway of conserved genes whose products mediate vesicle movement from early to recycling endosomes. The results provide new tools for understanding the integration of cytoplasmic structure and physiology in forming and maintaining the narrow diameter of single-cell tubules.
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9
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Kage-Nakadai E, Sun S, Iwata S, Yoshina S, Nishikawa Y, Mitani S. The small GTPase ARF-1.2 is a regulator of unicellular tube formation in Caenorhabditis elegans. J Physiol Sci 2019; 69:47-56. [PMID: 29704149 PMCID: PMC10717417 DOI: 10.1007/s12576-018-0617-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Accepted: 04/19/2018] [Indexed: 12/31/2022]
Abstract
The membrane trafficking events that regulate unicellular tube formation and maintenance are not well understood. Here, using an RNAi screen, we identified the small GTPase ARF1 homolog ARF-1.2 as a regulator of excretory tube formation in Caenorhabditis elegans. RNAi-mediated knockdown and knockout of the arf-1.2 gene resulted in the formation of large intracellular vacuoles at the growth sites (varicosities) of the excretory canals. arf-1.2 mutant animals were sensitive to hyperosmotic conditions. arf-1.2 RNAi affected the localization of the anion transporter SULP-8, which is expressed in the basal plasma membrane of the excretory canals, but did not affect the expression of SULP-4, which is expressed in the apical membrane. The phenotype of arf-1.2 mutants was suppressed by mutation of the small Rho GTPase CDC-42, a regulator of apical/basal traffic balance. These results suggest that ARF-1.2 plays an essential role in basal membrane traffic to regulate the formation of the unicellular excretory tube.
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Affiliation(s)
- Eriko Kage-Nakadai
- Department of Physiology, Tokyo Women's Medical University School of Medicine, 8-1, Kawada-cho, Shinjuku-ku, Tokyo, 162-8666, Japan
- Graduate School of Human Life Science, Osaka City University, Osaka, 558-8585, Japan
| | - Simo Sun
- Graduate School of Human Life Science, Osaka City University, Osaka, 558-8585, Japan
| | - Satoru Iwata
- Department of Physiology, Tokyo Women's Medical University School of Medicine, 8-1, Kawada-cho, Shinjuku-ku, Tokyo, 162-8666, Japan
| | - Sawako Yoshina
- Department of Physiology, Tokyo Women's Medical University School of Medicine, 8-1, Kawada-cho, Shinjuku-ku, Tokyo, 162-8666, Japan
| | - Yoshikazu Nishikawa
- Graduate School of Human Life Science, Osaka City University, Osaka, 558-8585, Japan
| | - Shohei Mitani
- Department of Physiology, Tokyo Women's Medical University School of Medicine, 8-1, Kawada-cho, Shinjuku-ku, Tokyo, 162-8666, Japan.
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10
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Tubular Excretory Canal Structure Depends on Intermediate Filaments EXC-2 and IFA-4 in Caenorhabditis elegans. Genetics 2018; 210:637-652. [PMID: 29945901 DOI: 10.1534/genetics.118.301078] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Accepted: 05/23/2018] [Indexed: 12/28/2022] Open
Abstract
The excretory canals of Caenorhabditis elegans are a model for understanding the maintenance of apical morphology in narrow single-celled tubes. Light and electron microscopy shows that mutants in exc-2 start to form canals normally, but these swell to develop large fluid-filled cysts that lack a complete terminal web at the apical surface, and accumulate filamentous material in the canal lumen. Here, whole-genome sequencing and gene rescue show that exc-2 encodes intermediate filament protein IFC-2 EXC-2/IFC-2 protein, fluorescently tagged via clustered regularly interspaced short palindromic repeats/Cas9, is located at the apical surface of the canals independently of other intermediate filament proteins. EXC-2 is also located in several other tissues, though the tagged isoforms are not seen in the larger intestinal tube. Tagged EXC-2 binds via pulldown to intermediate filament protein IFA-4, which is also shown to line the canal apical surface. Overexpression of either protein results in narrow but shortened canals. These results are consistent with a model whereby three intermediate filaments in the canals-EXC-2, IFA-4, and IFB-1-restrain swelling of narrow tubules in concert with actin filaments that guide the extension and direction of tubule outgrowth, while allowing the tube to bend as the animal moves.
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11
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Zhang N, Membreno E, Raj S, Zhang H, Khan LA, Gobel V. The C. elegans Excretory Canal as a Model for Intracellular Lumen Morphogenesis and In Vivo Polarized Membrane Biogenesis in a Single Cell: labeling by GFP-fusions, RNAi Interaction Screen and Imaging. J Vis Exp 2017. [PMID: 28994812 DOI: 10.3791/56101] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
The four C. elegans excretory canals are narrow tubes extended through the length of the animal from a single cell, with almost equally far extended intracellular endotubes that build and stabilize the lumen with a membrane and submembraneous cytoskeleton of apical character. The excretory cell expands its length approximately 2,000 times to generate these canals, making this model unique for the in vivo assessment of de novo polarized membrane biogenesis, intracellular lumen morphogenesis and unicellular tubulogenesis. The protocol presented here shows how to combine standard labeling, gain- and loss-of-function genetic or RNA interference (RNAi)-, and microscopic approaches to use this model to visually dissect and functionally analyze these processes on a molecular level. As an example of a labeling approach, the protocol outlines the generation of transgenic animals with fluorescent fusion proteins for live analysis of tubulogenesis. As an example of a genetic approach, it highlights key points of a visual RNAi-based interaction screen designed to modify a gain-of-function cystic canal phenotype. The specific methods described are how to: label and visualize the canals by expressing fluorescent proteins; construct a targeted RNAi library and strategize RNAi screening for the molecular analysis of canal morphogenesis; visually assess modifications of canal phenotypes; score them by dissecting fluorescence microscopy; characterize subcellular canal components at higher resolution by confocal microscopy; and quantify visual parameters. The approach is useful for the investigator who is interested in taking advantage of the C. elegans excretory canal for identifying and characterizing genes involved in the phylogenetically conserved processes of intracellular lumen and unicellular tube morphogenesis.
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Affiliation(s)
- Nan Zhang
- Mucosal Immunology and Biology Research Center, Developmental Biology and Genetics Core, Massachusetts General Hospital for Children, Harvard Medical School; College of Life Sciences, Jilin University
| | - Edward Membreno
- Mucosal Immunology and Biology Research Center, Developmental Biology and Genetics Core, Massachusetts General Hospital for Children, Harvard Medical School
| | - Susan Raj
- Mucosal Immunology and Biology Research Center, Developmental Biology and Genetics Core, Massachusetts General Hospital for Children, Harvard Medical School
| | - Hongjie Zhang
- Mucosal Immunology and Biology Research Center, Developmental Biology and Genetics Core, Massachusetts General Hospital for Children, Harvard Medical School; Faculty of Health Sciences, University of Macau
| | - Liakot A Khan
- Mucosal Immunology and Biology Research Center, Developmental Biology and Genetics Core, Massachusetts General Hospital for Children, Harvard Medical School;
| | - Verena Gobel
- Mucosal Immunology and Biology Research Center, Developmental Biology and Genetics Core, Massachusetts General Hospital for Children, Harvard Medical School;
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12
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Heldin J, O'Callaghan P, Hernández Vera R, Fuchs PF, Gerwins P, Kreuger J. FGD5 sustains vascular endothelial growth factor A (VEGFA) signaling through inhibition of proteasome-mediated VEGF receptor 2 degradation. Cell Signal 2017; 40:125-132. [PMID: 28927665 DOI: 10.1016/j.cellsig.2017.09.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Revised: 09/02/2017] [Accepted: 09/14/2017] [Indexed: 11/17/2022]
Abstract
The complete repertoire of endothelial functions elicited by FGD5, a guanine nucleotide exchange factor activating the Rho GTPase Cdc42, has yet to be elucidated. Here we explore FGD5's importance during vascular endothelial growth factor A (VEGFA) signaling via VEGF receptor 2 (VEGFR2) in human endothelial cells. In microvascular endothelial cells, FGD5 is located at the inner surface of the cell membrane as well as at the outer surface of EEA1-positive endosomes carrying VEGFR2. The latter finding prompted us to explore if FGD5 regulates VEGFR2 dynamics. We found that depletion of FGD5 in microvascular cells inhibited their migration towards a stable VEGFA gradient. Furthermore, depletion of FGD5 resulted in accelerated VEGFR2 degradation, which was reverted by lactacystin-mediated proteasomal inhibition. Our results thus suggest a mechanism whereby FGD5 sustains VEGFA signaling and endothelial cell chemotaxis via inhibition of proteasome-dependent VEGFR2 degradation.
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Affiliation(s)
- Johan Heldin
- Dept. of Pharmaceutical Biosciences, Pharmaceutical Cell Biology, Uppsala University, Uppsala, Sweden
| | - Paul O'Callaghan
- Dept. of Medical Cell Biology, Uppsala University, Uppsala, Sweden
| | | | | | - Pär Gerwins
- Dept. of Medical Cell Biology, Uppsala University, Uppsala, Sweden
| | - Johan Kreuger
- Dept. of Medical Cell Biology, Uppsala University, Uppsala, Sweden.
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13
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The Caenorhabditis elegans Excretory System: A Model for Tubulogenesis, Cell Fate Specification, and Plasticity. Genetics 2017; 203:35-63. [PMID: 27183565 DOI: 10.1534/genetics.116.189357] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Accepted: 03/07/2016] [Indexed: 12/12/2022] Open
Abstract
The excretory system of the nematode Caenorhabditis elegans is a superb model of tubular organogenesis involving a minimum of cells. The system consists of just three unicellular tubes (canal, duct, and pore), a secretory gland, and two associated neurons. Just as in more complex organs, cells of the excretory system must first adopt specific identities and then coordinate diverse processes to form tubes of appropriate topology, shape, connectivity, and physiological function. The unicellular topology of excretory tubes, their varied and sometimes complex shapes, and the dynamic reprogramming of cell identity and remodeling of tube connectivity that occur during larval development are particularly fascinating features of this organ. The physiological roles of the excretory system in osmoregulation and other aspects of the animal's life cycle are only beginning to be explored. The cellular mechanisms and molecular pathways used to build and shape excretory tubes appear similar to those used in both unicellular and multicellular tubes in more complex organs, such as the vertebrate vascular system and kidney, making this simple organ system a useful model for understanding disease processes.
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14
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Shaye DD, Greenwald I. A network of conserved formins, regulated by the guanine exchange factor EXC-5 and the GTPase CDC-42, modulates tubulogenesis in vivo. Development 2016; 143:4173-4181. [PMID: 27697907 DOI: 10.1242/dev.141861] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Accepted: 09/20/2016] [Indexed: 12/20/2022]
Abstract
The C. elegans excretory cell (EC) is a powerful model for tubulogenesis, a conserved process that requires precise cytoskeletal regulation. EXC-6, an ortholog of the disease-associated formin INF2, coordinates cell outgrowth and lumen formation during EC tubulogenesis by regulating F-actin at the tip of the growing canal and the dynamics of basolateral microtubules. EXC-6 functions in parallel with EXC-5/FGD, a predicted activator of the Rho GTPase Cdc42. Here, we identify the parallel pathway: EXC-5 functions through CDC-42 to regulate two other formins: INFT-2, another INF2 ortholog, and CYK-1, the sole ortholog of the mammalian diaphanous (mDia) family of formins. We show that INFT-2 promotes F-actin accumulation in the EC, and that CYK-1 inhibits INFT-2 to regulate F-actin levels and EXC-6-promoted outgrowth. As INF2 and mDia physically interact and cross-regulate in cultured cells, our work indicates that a conserved EXC-5-CDC-42 pathway modulates this regulatory interaction and that it is functionally important in vivo during tubulogenesis.
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Affiliation(s)
- Daniel D Shaye
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA .,Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA.,Department of Physiology and Biophysics, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Iva Greenwald
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA.,Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
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15
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Grussendorf KA, Trezza CJ, Salem AT, Al-Hashimi H, Mattingly BC, Kampmeyer DE, Khan LA, Hall DH, Göbel V, Ackley BD, Buechner M. Facilitation of Endosomal Recycling by an IRG Protein Homolog Maintains Apical Tubule Structure in Caenorhabditis elegans. Genetics 2016; 203:1789-806. [PMID: 27334269 PMCID: PMC4981278 DOI: 10.1534/genetics.116.192559] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2016] [Accepted: 06/15/2016] [Indexed: 02/08/2023] Open
Abstract
Determination of luminal diameter is critical to the function of small single-celled tubes. A series of EXC proteins, including EXC-1, prevent swelling of the tubular excretory canals in Caenorhabditis elegans In this study, cloning of exc-1 reveals it to encode a homolog of mammalian IRG proteins, which play roles in immune response and autophagy and are associated with Crohn's disease. Mutants in exc-1 accumulate early endosomes, lack recycling endosomes, and exhibit abnormal apical cytoskeletal structure in regions of enlarged tubules. EXC-1 interacts genetically with two other EXC proteins that also affect endosomal trafficking. In yeast two-hybrid assays, wild-type and putative constitutively active EXC-1 binds to the LIM-domain protein EXC-9, whose homolog, cysteine-rich intestinal protein, is enriched in mammalian intestine. These results suggest a model for IRG function in forming and maintaining apical tubule structure via regulation of endosomal recycling.
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Affiliation(s)
- Kelly A Grussendorf
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas 66045 Department of Biological Sciences, Minnesota State University, Mankato, Minnesota 56001
| | - Christopher J Trezza
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas 66045
| | - Alexander T Salem
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas 66045
| | - Hikmat Al-Hashimi
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas 66045
| | - Brendan C Mattingly
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas 66045
| | - Drew E Kampmeyer
- Department of Biological Sciences, Minnesota State University, Mankato, Minnesota 56001
| | - Liakot A Khan
- Mucosal Immunology and Biology Research Center, Developmental Biology and Genetics Core, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114
| | - David H Hall
- Department of Neuroscience, Center for Caenorhabditis elegans Anatomy, Albert Einstein College of Medicine, Bronx, New York 10461
| | - Verena Göbel
- Mucosal Immunology and Biology Research Center, Developmental Biology and Genetics Core, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114
| | - Brian D Ackley
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas 66045
| | - Matthew Buechner
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas 66045
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16
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Sundaram MV, Cohen JD. Time to make the doughnuts: Building and shaping seamless tubes. Semin Cell Dev Biol 2016; 67:123-131. [PMID: 27178486 DOI: 10.1016/j.semcdb.2016.05.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Revised: 05/04/2016] [Accepted: 05/06/2016] [Indexed: 10/21/2022]
Abstract
A seamless tube is a very narrow-bore tube that is composed of a single cell with an intracellular lumen and no adherens or tight junctions along its length. Many capillaries in the vertebrate vascular system are seamless tubes. Seamless tubes also are found in invertebrate organs, including the Drosophila trachea and the Caenorhabditis elegans excretory system. Seamless tube cells can be less than a micron in diameter, and they can adopt very simple "doughnut-like" shapes or very complex, branched shapes comparable to those of neurons. The unusual topology and varied shapes of seamless tubes raise many basic cell biological questions about how cells form and maintain such structures. The prevalence of seamless tubes in the vascular system means that answering such questions has significant relevance to human health. In this review, we describe selected examples of seamless tubes in animals and discuss current models for how seamless tubes develop and are shaped, focusing particularly on insights that have come from recent studies in Drosophila and C. elegans.
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Affiliation(s)
- Meera V Sundaram
- Dept. of Genetics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA.
| | - Jennifer D Cohen
- Dept. of Genetics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
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17
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Quintin S, Gally C, Labouesse M. Noncentrosomal microtubules in C. elegans epithelia. Genesis 2016; 54:229-42. [PMID: 26789944 DOI: 10.1002/dvg.22921] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Revised: 01/12/2016] [Accepted: 01/14/2016] [Indexed: 11/12/2022]
Abstract
The microtubule cytoskeleton has a dual contribution to cell organization. First, microtubules help displace chromosomes and provide tracks for organelle transport. Second, microtubule rigidity confers specific mechanical properties to cells, which are crucial in cilia or mechanosensory structures. Here we review the recently uncovered organization and functions of noncentrosomal microtubules in C. elegans epithelia, focusing on how they contribute to nuclear positioning and protein transport. In addition, we describe recent data illustrating how the microtubule and actin cytoskeletons interact to achieve those functions.
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Affiliation(s)
- Sophie Quintin
- Development and Stem Cells Department, IGBMC - CNRS UMR 7104/INSERM U964/Université de Strasbourg, 1 Rue Laurent Fries, Illkirch, 67400, France
| | - Christelle Gally
- Development and Stem Cells Department, IGBMC - CNRS UMR 7104/INSERM U964/Université de Strasbourg, 1 Rue Laurent Fries, Illkirch, 67400, France
| | - Michel Labouesse
- Université Pierre Et Marie Curie, IBPS, CNRS UMR7622, 7 Quai St-Bernard, Paris, 75005, France
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18
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Shaye DD, Greenwald I. The disease-associated formin INF2/EXC-6 organizes lumen and cell outgrowth during tubulogenesis by regulating F-actin and microtubule cytoskeletons. Dev Cell 2015; 32:743-55. [PMID: 25771894 DOI: 10.1016/j.devcel.2015.01.009] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Revised: 12/02/2014] [Accepted: 01/13/2015] [Indexed: 10/23/2022]
Abstract
We investigate how outgrowth at the basolateral cell membrane is coordinated with apical lumen formation in the development of a biological tube by characterizing exc-6, a gene required for C. elegans excretory cell (EC) tubulogenesis. We show that EXC-6 is orthologous to the human formin INF2, which polymerizes filamentous actin (F-actin) and binds microtubules (MTs) in vitro. Dominant INF2 mutations cause focal segmental glomerulosclerosis (FSGS), a kidney disease, and FSGS+Charcot-Marie-Tooth neuropathy. We show that activated INF2 can substitute for EXC-6 in C. elegans and that disease-associated mutations cause constitutive activity. Using genetic analysis and live imaging, we show that exc-6 regulates MT and F-actin accumulation at EC tips and dynamics of basolateral-localized MTs, indicating that EXC-6 organizes F-actin and MT cytoskeletons during tubulogenesis. The pathology associated with INF2 mutations is believed to reflect misregulation of F-actin, but our results suggest alternative or additional mechanisms via effects on MT dynamics.
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Affiliation(s)
- Daniel D Shaye
- Howard Hughes Medical Institute, Columbia University, College of Physicians and Surgeons, New York, NY 10032, USA.
| | - Iva Greenwald
- Howard Hughes Medical Institute, Columbia University, College of Physicians and Surgeons, New York, NY 10032, USA; Department of Biochemistry and Molecular Biophysics, Columbia University, College of Physicians and Surgeons, New York, NY 10032, USA; Department of Genetics and Development, Columbia University, College of Physicians and Surgeons, New York, NY 10032, USA.
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19
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Lant B, Yu B, Goudreault M, Holmyard D, Knight JDR, Xu P, Zhao L, Chin K, Wallace E, Zhen M, Gingras AC, Derry WB. CCM-3/STRIPAK promotes seamless tube extension through endocytic recycling. Nat Commun 2015; 6:6449. [PMID: 25743393 DOI: 10.1038/ncomms7449] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 01/29/2015] [Indexed: 01/25/2023] Open
Abstract
The mechanisms governing apical membrane assembly during biological tube development are poorly understood. Here, we show that extension of the C. elegans excretory canal requires cerebral cavernous malformation 3 (CCM-3), independent of the CCM1 orthologue KRI-1. Loss of ccm-3 causes canal truncations and aggregations of canaliculular vesicles, which form ectopic lumen (cysts). We show that CCM-3 localizes to the apical membrane, and in cooperation with GCK-1 and STRIPAK, promotes CDC-42 signalling, Golgi stability and endocytic recycling. We propose that endocytic recycling is mediated through the CDC-42-binding kinase MRCK-1, which interacts physically with CCM-3-STRIPAK. We further show canal membrane integrity to be dependent on the exocyst complex and the actin cytoskeleton. This work reveals novel in vivo roles of CCM-3·STRIPAK in regulating tube extension and membrane integrity through small GTPase signalling and vesicle dynamics, which may help explain the severity of CCM3 mutations in patients.
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Affiliation(s)
- Benjamin Lant
- Developmental and Stem Cell Biology Program, The Hospital for Sick Children, Peter Gilgan Centre for Research and Learning, 686 Bay Street, Toronto, Ontario, Canada M5G 0A4
| | - Bin Yu
- Developmental and Stem Cell Biology Program, The Hospital for Sick Children, Peter Gilgan Centre for Research and Learning, 686 Bay Street, Toronto, Ontario, Canada M5G 0A4
| | - Marilyn Goudreault
- Lunenfeld-Tanenbaum Research Institute at Mount Sinai Hospital, 600 University Avenue, Toronto, Ontario, Canada M5G 1X5
| | - Doug Holmyard
- Lunenfeld-Tanenbaum Research Institute at Mount Sinai Hospital, 600 University Avenue, Toronto, Ontario, Canada M5G 1X5
| | - James D R Knight
- Lunenfeld-Tanenbaum Research Institute at Mount Sinai Hospital, 600 University Avenue, Toronto, Ontario, Canada M5G 1X5
| | - Peter Xu
- Department of Molecular Genetics, University of Toronto, 1 King's College Circle, Toronto, Ontario, Canada M5S 1A8
| | - Linda Zhao
- Developmental and Stem Cell Biology Program, The Hospital for Sick Children, Peter Gilgan Centre for Research and Learning, 686 Bay Street, Toronto, Ontario, Canada M5G 0A4
| | - Kelly Chin
- Developmental and Stem Cell Biology Program, The Hospital for Sick Children, Peter Gilgan Centre for Research and Learning, 686 Bay Street, Toronto, Ontario, Canada M5G 0A4
| | - Evan Wallace
- 1] Developmental and Stem Cell Biology Program, The Hospital for Sick Children, Peter Gilgan Centre for Research and Learning, 686 Bay Street, Toronto, Ontario, Canada M5G 0A4 [2] Department of Molecular Genetics, University of Toronto, 1 King's College Circle, Toronto, Ontario, Canada M5S 1A8
| | - Mei Zhen
- 1] Lunenfeld-Tanenbaum Research Institute at Mount Sinai Hospital, 600 University Avenue, Toronto, Ontario, Canada M5G 1X5 [2] Department of Molecular Genetics, University of Toronto, 1 King's College Circle, Toronto, Ontario, Canada M5S 1A8
| | - Anne-Claude Gingras
- 1] Lunenfeld-Tanenbaum Research Institute at Mount Sinai Hospital, 600 University Avenue, Toronto, Ontario, Canada M5G 1X5 [2] Department of Molecular Genetics, University of Toronto, 1 King's College Circle, Toronto, Ontario, Canada M5S 1A8
| | - W Brent Derry
- 1] Developmental and Stem Cell Biology Program, The Hospital for Sick Children, Peter Gilgan Centre for Research and Learning, 686 Bay Street, Toronto, Ontario, Canada M5G 0A4 [2] Department of Molecular Genetics, University of Toronto, 1 King's College Circle, Toronto, Ontario, Canada M5S 1A8
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20
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Wang X, Piccolo CW, Cohen BM, Buttner EA. Transient receptor potential melastatin (TRPM) channels mediate clozapine-induced phenotypes in Caenorhabditis elegans. J Neurogenet 2014; 28:86-97. [PMID: 24564792 DOI: 10.3109/01677063.2013.879717] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The molecular mechanisms of action of antipsychotic drugs (APDs) are not fully understood. Here, we characterize phenotypes of missense and knockout mutations in the Caenorhabditis elegans transient receptor potential melastatin (TRPM) channel ortholog gtl-2, a candidate APD target identified in a genome-wide RNAi (RNA interference) screen for Suppressors of Clozapine-induced Larval Arrest (scla genes). We then employ the developmental phenotypes of gtl-2(lf) mutants to validate our previous gtl-2(RNAi) result. GTL-2 acts in the excretory canal cell to regulate Mg(2+) homeostasis. Using exc (excretory canal abnormal) gene mutants, we demonstrate that excretory canal cell function is necessary for clozapine-induced developmental delay and lethality. Moreover, cell-specific promoter-driven expression studies reveal that GTL-2 function in the excretory canal cell is important for its role in the SCLA phenotype. We then investigate the mechanism by which GTL-2 function in the excretory canal cell impacts clozapine-induced phenotypes. gtl-2(lf) mutations cause hypermagnesemia, and we show that exposure of the wild-type strain to high Mg(2+) phenocopies gtl-2(lf) with respect to suppression of clozapine-induced developmental delay and lethality. Our results suggest that GTL-2 TRPM channel function in the excretory canal cell is important for clozapine's developmental effects. TRP channels are expressed in mammalian brain and are implicated in the pathogenesis of mental illnesses but have not been previously implicated in APD action.
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Affiliation(s)
- Xin Wang
- Department of Psychiatry, Harvard Medical School , Boston, Massachusetts , USA
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21
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Abstract
Metazoans require epithelial and endothelial tubes to transport liquids and gasses throughout their bodies. Although biological tubes may look relatively similar at first glance, there are multiple and distinct mechanisms by which tubes form and even more regulatory events driving the cell shape changes that produce tubes of specific dimensions. An overview of the current understanding of the molecular processes and physical forces involved in tubulogenesis is presented in this review and the accompanying poster.
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Affiliation(s)
- M Luisa Iruela-Arispe
- Department of Molecular, Cell and Developmental Biology, Molecular Biology Institute, Jonsson Comprehensive Cancer Center, University of California, Los Angeles, CA 90095, USA.
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22
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Jiang L, Phang JM, Yu J, Harrop SJ, Sokolova AV, Duff AP, Wilk KE, Alkhamici H, Breit SN, Valenzuela SM, Brown LJ, Curmi PMG. CLIC proteins, ezrin, radixin, moesin and the coupling of membranes to the actin cytoskeleton: a smoking gun? BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2013; 1838:643-57. [PMID: 23732235 DOI: 10.1016/j.bbamem.2013.05.025] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2013] [Revised: 05/20/2013] [Accepted: 05/21/2013] [Indexed: 12/20/2022]
Abstract
The CLIC proteins are a highly conserved family of metazoan proteins with the unusual ability to adopt both soluble and integral membrane forms. The physiological functions of CLIC proteins may include enzymatic activity in the soluble form and anion channel activity in the integral membrane form. CLIC proteins are associated with the ERM proteins: ezrin, radixin and moesin. ERM proteins act as cross-linkers between membranes and the cortical actin cytoskeleton. Both CLIC and ERM proteins are controlled by Rho family small GTPases. CLIC proteins, ERM and Rho GTPases act in a concerted manner to control active membrane processes including the maintenance of microvillar structures, phagocytosis and vesicle trafficking. All of these processes involve the interaction of membranes with the underlying cortical actin cytoskeleton. The relationships between Rho GTPases, CLIC proteins, ERM proteins and the membrane:actin cytoskeleton interface are reviewed. Speculative models are proposed involving the formation of localised multi-protein complexes on the membrane surface that assemble via multiple weak interactions. This article is part of a Special Issue entitled: Reciprocal influences between cell cytoskeleton and membrane channels, receptors and transporters. Guest Editor: Jean Claude Hervé.
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Affiliation(s)
- Lele Jiang
- St Vincent's Centre for Applied Medical Research, St Vincent's Hospital, Sydney, NSW 2010, Australia
| | - Juanita M Phang
- School of Physics, The University of New South Wales, Sydney, NSW 2052, Australia
| | - Jiang Yu
- School of Physics, The University of New South Wales, Sydney, NSW 2052, Australia
| | - Stephen J Harrop
- School of Physics, The University of New South Wales, Sydney, NSW 2052, Australia
| | - Anna V Sokolova
- Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW, Australia
| | - Anthony P Duff
- Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW, Australia
| | - Krystyna E Wilk
- School of Physics, The University of New South Wales, Sydney, NSW 2052, Australia
| | - Heba Alkhamici
- School of Medical and Molecular Biosciences, The University of Technology Sydney, Sydney, NSW 2007, Australia
| | - Samuel N Breit
- St Vincent's Centre for Applied Medical Research, St Vincent's Hospital, Sydney, NSW 2010, Australia
| | - Stella M Valenzuela
- School of Medical and Molecular Biosciences, The University of Technology Sydney, Sydney, NSW 2007, Australia
| | - Louise J Brown
- Department of Chemistry and Biomolecular Sciences, Macquarie University, Sydney, NSW 2109, Australia
| | - Paul M G Curmi
- St Vincent's Centre for Applied Medical Research, St Vincent's Hospital, Sydney, NSW 2010, Australia; School of Physics, The University of New South Wales, Sydney, NSW 2052, Australia.
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23
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Khan LA, Zhang H, Abraham N, Sun L, Fleming JT, Buechner M, Hall DH, Gobel V. Intracellular lumen extension requires ERM-1-dependent apical membrane expansion and AQP-8-mediated flux. Nat Cell Biol 2013; 15:143-56. [PMID: 23334498 PMCID: PMC4091717 DOI: 10.1038/ncb2656] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2012] [Accepted: 11/16/2012] [Indexed: 01/29/2023]
Abstract
Many unicellular tubes such as capillaries form lumens intracellularly, a process that is not well understood. Here we show that the cortical membrane organizer ERM-1 is required to expand the intracellular apical/lumenal membrane and its actin undercoat during single-cell C.elegans excretory canal morphogenesis. We characterize AQP-8, identified in an ERM-1 overexpression (ERM-1[++]) suppressor screen, as a canalicular aquaporin that interacts with ERM-1 in lumen extension in a mercury-sensitive manner, implicating water-channel activity. AQP-8 is transiently recruited to the lumen by ERM-1, co-localizing in peri-lumenal cuffs interspaced along expanding canals. An ERM-1[++]-mediated increase in the number of lumen-associated canaliculi is reversed by AQP-8 depletion. We propose that the ERM-1-AQP-8 interaction propels lumen extension by translumenal flux, suggesting a direct morphogenetic effect of water-channel-regulated fluid pressure.
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Affiliation(s)
- Liakot A Khan
- Department of Pediatrics, Massachusetts General Hospital, Boston, 02114, USA
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24
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Kolotuev I, Hyenne V, Schwab Y, Rodriguez D, Labouesse M. A pathway for unicellular tube extension depending on the lymphatic vessel determinant Prox1 and on osmoregulation. Nat Cell Biol 2013; 15:157-68. [DOI: 10.1038/ncb2662] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2012] [Accepted: 11/26/2012] [Indexed: 01/14/2023]
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25
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McShea MA, Schmidt KL, Dubuke ML, Baldiga CE, Sullender ME, Reis AL, Zhang S, O'Toole SM, Jeffers MC, Warden RM, Kenney AH, Gosselin J, Kuhlwein M, Hashmi SK, Stringham EG, Ryder EF. Abelson interactor-1 (ABI-1) interacts with MRL adaptor protein MIG-10 and is required in guided cell migrations and process outgrowth in C. elegans. Dev Biol 2012; 373:1-13. [PMID: 23022657 DOI: 10.1016/j.ydbio.2012.09.017] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2012] [Revised: 09/12/2012] [Accepted: 09/21/2012] [Indexed: 11/19/2022]
Abstract
Directed cell migration and process outgrowth are vital to proper development of many metazoan tissues. These processes are dependent on reorganization of the actin cytoskeleton in response to external guidance cues. During development of the nervous system, the MIG-10/RIAM/Lamellipodin (MRL) signaling proteins are thought to transmit positional information from surface guidance cues to the actin polymerization machinery, and thus to promote polarized outgrowth of axons. In C. elegans, mutations in the MRL family member gene mig-10 result in animals that have defects in axon guidance, neuronal migration, and the outgrowth of the processes or 'canals' of the excretory cell, which is required for osmoregulation in the worm. In addition, mig-10 mutant animals have recently been shown to have defects in clustering of vesicles at the synapse. To determine additional molecular partners of MIG-10, we conducted a yeast two-hybrid screen using isoform MIG-10A as bait and isolated Abelson-interactor protein-1 (ABI-1). ABI-1, a downstream target of Abl non-receptor tyrosine kinase, is a member of the WAVE regulatory complex (WRC) involved in the initiation of actin polymerization. Further analysis using a co-immunoprecipitation system confirmed the interaction of MIG-10 and ABI-1 and showed that it requires the SH3 domain of ABI-1. Single mutants for mig-10 and abi-1 displayed similar phenotypes of incomplete migration of the ALM neurons and truncated outgrowth of the excretory cell canals, suggesting that the ABI-1/MIG-10 interaction is relevant in vivo. Cell autonomous expression of MIG-10 isoforms rescued both the neuronal migration and the canal outgrowth defects, showing that MIG-10 functions autonomously in the ALM neurons and the excretory cell. These results suggest that MIG-10 and ABI-1 interact physically to promote cell migration and process outgrowth in vivo. In the excretory canal, ABI-1 is thought to act downstream of UNC-53/NAV2, linking this large scaffolding protein to actin polymerization during excretory canal outgrowth. abi-1(RNAi) enhanced the excretory canal truncation observed in mig-10 mutants, while double mutant analysis between unc-53 and mig-10 showed no increased truncation of the posterior canal beyond that observed in mig-10 mutants. Morphological analysis of mig-10 and unc-53 mutants showed that these genes regulate canal diameter as well as its length, suggesting that defective lumen formation may be linked to the ability of the excretory canal to grow out longitudinally. Taken together, our results suggest that MIG-10, UNC-53, and ABI-1 act sequentially to mediate excretory cell process outgrowth.
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Affiliation(s)
- Molly A McShea
- Department of Biology and Biotechnology, Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA 01609, USA.
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26
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Abdus-Saboor I, Stone CE, Murray JI, Sundaram MV. The Nkx5/HMX homeodomain protein MLS-2 is required for proper tube cell shape in the C. elegans excretory system. Dev Biol 2012; 366:298-307. [PMID: 22537498 DOI: 10.1016/j.ydbio.2012.03.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2012] [Revised: 03/26/2012] [Accepted: 03/28/2012] [Indexed: 01/20/2023]
Abstract
Cells perform wide varieties of functions that are facilitated, in part, by adopting unique shapes. Many of the genes and pathways that promote cell fate specification have been elucidated. However, relatively few transcription factors have been identified that promote shape acquisition after fate specification. Here we show that the Nkx5/HMX homeodomain protein MLS-2 is required for cellular elongation and shape maintenance of two tubular epithelial cells in the C. elegans excretory system, the duct and pore cells. The Nkx5/HMX family is highly conserved from sea urchins to humans, with known roles in neuronal and glial development. MLS-2 is expressed in the duct and pore, and defects in mls-2 mutants first arise when the duct and pore normally adopt unique shapes. MLS-2 cooperates with the EGF-Ras-ERK pathway to turn on the LIN-48/Ovo transcription factor in the duct cell during morphogenesis. These results reveal a novel interaction between the Nkx5/HMX family and the EGF-Ras pathway and implicate a transcription factor, MLS-2, as a regulator of cell shape.
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Affiliation(s)
- Ishmail Abdus-Saboor
- Department of Genetics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
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27
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Mancuso VP, Parry JM, Storer L, Poggioli C, Nguyen KCQ, Hall DH, Sundaram MV. Extracellular leucine-rich repeat proteins are required to organize the apical extracellular matrix and maintain epithelial junction integrity in C. elegans. Development 2012; 139:979-90. [PMID: 22278925 PMCID: PMC3274359 DOI: 10.1242/dev.075135] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/20/2011] [Indexed: 12/13/2022]
Abstract
Epithelial cells are linked by apicolateral junctions that are essential for tissue integrity. Epithelial cells also secrete a specialized apical extracellular matrix (ECM) that serves as a protective barrier. Some components of the apical ECM, such as mucins, can influence epithelial junction remodeling and disassembly during epithelial-to-mesenchymal transition (EMT). However, the molecular composition and biological roles of the apical ECM are not well understood. We identified a set of extracellular leucine-rich repeat only (eLRRon) proteins in C. elegans (LET-4 and EGG-6) that are expressed on the apical surfaces of epidermal cells and some tubular epithelia, including the excretory duct and pore. A previously characterized paralog, SYM-1, is also expressed in epidermal cells and secreted into the apical ECM. Related mammalian eLRRon proteins, such as decorin or LRRTM1-3, influence stromal ECM or synaptic junction organization, respectively. Mutants lacking one or more of the C. elegans epithelial eLRRon proteins show multiple defects in apical ECM organization, consistent with these proteins contributing to the embryonic sheath and cuticular ECM. Furthermore, epithelial junctions initially form in the correct locations, but then rupture at the time of cuticle secretion and remodeling of cell-matrix interactions. This work identifies epithelial eLRRon proteins as important components and organizers of the pre-cuticular and cuticular apical ECM, and adds to the small but growing body of evidence linking the apical ECM to epithelial junction stability. We propose that eLRRon-dependent apical ECM organization contributes to cell-cell adhesion and may modulate epithelial junction dynamics in both normal and disease situations.
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Affiliation(s)
- Vincent P. Mancuso
- Department of Genetics, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Jean M. Parry
- Department of Genetics, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Luke Storer
- Department of Genetics, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Corey Poggioli
- Department of Genetics, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Ken C. Q. Nguyen
- Department of Neuroscience, Center for C. elegans Anatomy, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - David H. Hall
- Department of Neuroscience, Center for C. elegans Anatomy, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Meera V. Sundaram
- Department of Genetics, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA 19104, USA
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