1
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Hall AE, Klompstra D, Nance J. C. elegans Afadin is required for epidermal morphogenesis and functionally interfaces with the cadherin-catenin complex and RhoGAP PAC-1/ARHGAP21. Dev Biol 2024; 511:12-25. [PMID: 38556137 PMCID: PMC11088504 DOI: 10.1016/j.ydbio.2024.03.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 03/07/2024] [Accepted: 03/25/2024] [Indexed: 04/02/2024]
Abstract
During epithelial morphogenesis, the apical junctions connecting cells must remodel as cells change shape and make new connections with their neighbors. In the C. elegans embryo, new apical junctions form when epidermal cells migrate and seal with one another to encase the embryo in skin ('ventral enclosure'), and junctions remodel when epidermal cells change shape to squeeze the embryo into a worm shape ('elongation'). The junctional cadherin-catenin complex (CCC), which links epithelial cells to each other and to cortical actomyosin, is essential for C. elegans epidermal morphogenesis. RNAi genetic enhancement screens have identified several genes encoding proteins that interact with the CCC to promote epidermal morphogenesis, including the scaffolding protein Afadin (AFD-1), whose depletion alone results in only minor morphogenesis defects. Here, by creating a null mutation in afd-1, we show that afd-1 provides a significant contribution to ventral enclosure and elongation on its own. Unexpectedly, we find that afd-1 mutant phenotypes are strongly modified by diet, revealing a previously unappreciated parental nutritional input to morphogenesis. We identify functional interactions between AFD-1 and the CCC by demonstrating that E-cadherin is required for the polarized distribution of AFD-1 to cell contact sites in early embryos. Finally, we show that afd-1 promotes the enrichment of polarity regulator, and CCC-interacting protein, PAC-1/ARHGAP21 to cell contact sites, and we identify genetic interactions suggesting that afd-1 and pac-1 regulate epidermal morphogenesis at least in part through parallel mechanisms. Our findings reveal that C. elegans AFD-1 makes a significant contribution to epidermal morphogenesis and functionally interfaces with core and associated CCC proteins.
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Affiliation(s)
- Allison E Hall
- Department of Cell Biology, NYU School of Medicine, New York, NY, 10016, USA; Skirball Institute of Biomolecular Medicine, NYU School of Medicine, New York, NY, 10016, USA; Regis University, Biology Department, Denver, CO, 80221, USA.
| | - Diana Klompstra
- Department of Cell Biology, NYU School of Medicine, New York, NY, 10016, USA; Skirball Institute of Biomolecular Medicine, NYU School of Medicine, New York, NY, 10016, USA
| | - Jeremy Nance
- Department of Cell Biology, NYU School of Medicine, New York, NY, 10016, USA; Skirball Institute of Biomolecular Medicine, NYU School of Medicine, New York, NY, 10016, USA; University of Wisconsin - Madison, Department of Cell and Regenerative Biology and Center for Quantitative Cell Imaging, Madison, WI, 53706, USA.
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2
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Sefik E, Duan K, Li Y, Sholar B, Evans L, Pincus J, Ammar Z, Murphy MM, Klaiman C, Saulnier CA, Pulver SL, Goldman-Yassen AE, Guo Y, Walker EF, Li L, Mulle JG, Shultz S. Structural deviations of the posterior fossa and the cerebellum and their cognitive links in a neurodevelopmental deletion syndrome. Mol Psychiatry 2024:10.1038/s41380-024-02584-8. [PMID: 38744992 DOI: 10.1038/s41380-024-02584-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 04/16/2024] [Accepted: 04/23/2024] [Indexed: 05/16/2024]
Abstract
High-impact genetic variants associated with neurodevelopmental disorders provide biologically-defined entry points for mechanistic investigation. The 3q29 deletion (3q29Del) is one such variant, conferring a 40-100-fold increased risk for schizophrenia, as well as high risk for autism and intellectual disability. However, the mechanisms leading to neurodevelopmental disability remain largely unknown. Here, we report the first in vivo quantitative neuroimaging study in individuals with 3q29Del (N = 24) and neurotypical controls (N = 1608) using structural MRI. Given prior radiology reports of posterior fossa abnormalities in 3q29Del, we focused our investigation on the cerebellum and its tissue-types and lobules. Additionally, we compared the prevalence of cystic/cyst-like malformations of the posterior fossa between 3q29Del and controls and examined the association between neuroanatomical findings and quantitative traits to probe gene-brain-behavior relationships. 3q29Del participants had smaller cerebellar cortex volumes than controls, before and after correction for intracranial volume (ICV). An anterior-posterior gradient emerged in finer grained lobule-based and voxel-wise analyses. 3q29Del participants also had larger cerebellar white matter volumes than controls following ICV-correction and displayed elevated rates of posterior fossa arachnoid cysts and mega cisterna magna findings independent of cerebellar volume. Cerebellar white matter and subregional gray matter volumes were associated with visual-perception and visual-motor integration skills as well as IQ, while cystic/cyst-like malformations yielded no behavioral link. In summary, we find that abnormal development of cerebellar structures may represent neuroimaging-based biomarkers of cognitive and sensorimotor function in 3q29Del, adding to the growing evidence identifying cerebellar pathology as an intersection point between syndromic and idiopathic forms of neurodevelopmental disabilities.
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Affiliation(s)
- Esra Sefik
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA, USA
- Department of Psychology, Emory University, Atlanta, GA, USA
| | - Kuaikuai Duan
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA
- Tri-institutional Center for Translational Research in Neuroimaging and Data Science, Georgia State University, Georgia Institute of Technology, Emory University, Atlanta, GA, USA
| | - Yiheng Li
- Department of Biostatistics and Bioinformatics, Rollins School of Public Health, Emory University, Atlanta, GA, USA
| | - Brittney Sholar
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA
- Marcus Autism Center, Children's Healthcare of Atlanta and Emory University School of Medicine, Atlanta, GA, USA
| | - Lindsey Evans
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA
- Marcus Autism Center, Children's Healthcare of Atlanta and Emory University School of Medicine, Atlanta, GA, USA
| | - Jordan Pincus
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA
- Marcus Autism Center, Children's Healthcare of Atlanta and Emory University School of Medicine, Atlanta, GA, USA
| | - Zeena Ammar
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA
- Marcus Autism Center, Children's Healthcare of Atlanta and Emory University School of Medicine, Atlanta, GA, USA
| | - Melissa M Murphy
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA
| | - Cheryl Klaiman
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA
- Marcus Autism Center, Children's Healthcare of Atlanta and Emory University School of Medicine, Atlanta, GA, USA
| | - Celine A Saulnier
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA
- Neurodevelopmental Assessment & Consulting Services, Atlanta, GA, USA
| | - Stormi L Pulver
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA
- Marcus Autism Center, Children's Healthcare of Atlanta and Emory University School of Medicine, Atlanta, GA, USA
| | - Adam E Goldman-Yassen
- Department of Radiology, Children's Healthcare of Atlanta, Atlanta, GA, USA
- Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, GA, USA
| | - Ying Guo
- Department of Biostatistics and Bioinformatics, Rollins School of Public Health, Emory University, Atlanta, GA, USA
| | - Elaine F Walker
- Department of Psychology, Emory University, Atlanta, GA, USA
| | - Longchuan Li
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA
- Marcus Autism Center, Children's Healthcare of Atlanta and Emory University School of Medicine, Atlanta, GA, USA
| | - Jennifer G Mulle
- Department of Psychiatry, Robert Wood Johnson Medical School, Rutgers University, New Brunswick, NJ, USA.
| | - Sarah Shultz
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA.
- Marcus Autism Center, Children's Healthcare of Atlanta and Emory University School of Medicine, Atlanta, GA, USA.
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3
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Behbehani R, Johnson C, Holmes AJ, Gratian MJ, Mulvihill DP, Buss F. The two C. elegans class VI myosins, SPE-15/HUM-3 and HUM-8, share similar motor properties, but have distinct developmental and tissue expression patterns. Front Physiol 2024; 15:1368054. [PMID: 38660538 PMCID: PMC11040104 DOI: 10.3389/fphys.2024.1368054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Accepted: 03/22/2024] [Indexed: 04/26/2024] Open
Abstract
Myosins of class VI move toward the minus-end of actin filaments and play vital roles in cellular processes such as endocytosis, autophagy, protein secretion, and the regulation of actin filament dynamics. In contrast to the majority of metazoan organisms examined to date which contain a single MYO6 gene, C. elegans, possesses two MYO6 homologues, SPE-15/HUM-3 and HUM-8. Through a combination of in vitro biochemical/biophysical analysis and cellular assays, we confirmed that both SPE-15/HUM-3 and HUM-8 exhibit reverse directionality, velocities, and ATPase activity similar to human MYO6. Our characterization also revealed that unlike SPE-15/HUM-3, HUM-8 is expressed as two distinct splice isoforms, one with an additional unique 14 amino acid insert in the cargo-binding domain. While lipid and adaptor binding sites are conserved in SPE-15/HUM-3 and HUM-8, this conservation does not enable recruitment to endosomes in mammalian cells. Finally, we performed super-resolution confocal imaging on transgenic worms expressing either mNeonGreen SPE-15/HUM-3 or wrmScarlet HUM-8. Our results show a clear distinction in tissue distribution between SPE-15/HUM-3 and HUM-8. While SPE-15/HUM-3 exhibited specific expression in the gonads and neuronal tissue in the head, HUM-8 was exclusively localized in the intestinal epithelium. Overall, these findings align with the established tissue distributions and localizations of human MYO6.
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Affiliation(s)
- Ranya Behbehani
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom
| | - Chloe Johnson
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom
| | - Alexander J. Holmes
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom
| | - Matthew J. Gratian
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom
| | | | - Folma Buss
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom
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Rabino A, Awadia S, Ali N, Edson A, Garcia-Mata R. The Scribble/SGEF/Dlg1 complex regulates the stability of apical junctions in epithelial cells. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.26.586884. [PMID: 38585765 PMCID: PMC10996629 DOI: 10.1101/2024.03.26.586884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
SGEF, a RhoG specific GEF, can form a ternary complex with the Scribble polarity complex proteins Scribble and Dlg1, which regulates the formation and maintenance of adherens junctions and barrier function of epithelial cells. Notably, silencing SGEF results in a dramatic downregulation of the expression of both E-cadherin and ZO-1. However, the molecular mechanisms involved in the regulation of this pathway are not known. Here, we describe a novel signaling pathway governed by the Scribble/SGEF/Dlg1 complex. Our results show that an intact ternary complex is required to maintain the stability of the apical junctions, the expression of ZO-1, and TJ permeability. In contrast, only SGEF is necessary to regulate E-cadherin expression. The absence of SGEF destabilizes the E-cadherin/catenin complex at the membrane, triggering a positive feedback loop that exacerbates the phenotype through the repression of E-cadherin transcription in a process that involves the internalization of E-cadherin by endocytosis, β-catenin signaling and the transcriptional repressor Slug.
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Affiliation(s)
- Agustin Rabino
- Department of Biological Sciences, University of Toledo, Toledo, OH, USA
| | - Sahezeel Awadia
- Department of Biological Sciences, University of Toledo, Toledo, OH, USA
| | - Nabaa Ali
- Department of Biological Sciences, University of Toledo, Toledo, OH, USA
| | - Amber Edson
- Department of Biological Sciences, University of Toledo, Toledo, OH, USA
| | - Rafael Garcia-Mata
- Department of Biological Sciences, University of Toledo, Toledo, OH, USA
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5
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Binti S, Linder AG, Edeen PT, Fay DS. A conserved protein tyrosine phosphatase, PTPN-22, functions in diverse developmental processes in C. elegans. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.12.584557. [PMID: 38559252 PMCID: PMC10980042 DOI: 10.1101/2024.03.12.584557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
Protein tyrosine phosphatases non-receptor type (PTPNs) have been studied extensively in the context of the adaptive immune system; however, their roles beyond immunoregulation are less well explored. Here we identify novel functions for the conserved C. elegans phosphatase PTPN-22, establishing its role in nematode molting, cell adhesion, and cytoskeletal regulation. Through a non-biased genetic screen, we found that loss of PTPN-22 phosphatase activity suppressed molting defects caused by loss-of-function mutations in the conserved NIMA-related kinases NEKL-2 (human NEK8/NEK9) and NEKL-3 (human NEK6/NEK7), which act at the interface of membrane trafficking and actin regulation. To better understand the functions of PTPN-22, we carried out proximity labeling studies to identify candidate interactors of PTPN-22 during development. Through this approach we identified the CDC42 guanine-nucleotide exchange factor DNBP-1 (human DNMBP) as an in vivo partner of PTPN-22. Consistent with this interaction, loss of DNBP-1 also suppressed nekl-associated molting defects. Genetic analysis, co-localization studies, and proximity labeling revealed roles for PTPN-22 in several epidermal adhesion complexes, including C. elegans hemidesmosomes, suggesting that PTPN-22 plays a broad role in maintaining the structural integrity of tissues. Localization and proximity labeling also implicated PTPN-22 in functions connected to nucleocytoplasmic transport and mRNA regulation, particularly within the germline, as nearly one-third of proteins identified by PTPN-22 proximity labeling are known P granule components. Collectively, these studies highlight the utility of combined genetic and proteomic approaches for identifying novel gene functions.
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Affiliation(s)
- Shaonil Binti
- Department of Molecular Biology, College of Agriculture, Life Sciences and Natural Resources, University of Wyoming, 1000 E. University Ave., Laramie, Wyoming
| | - Adison G Linder
- Department of Molecular Biology, College of Agriculture, Life Sciences and Natural Resources, University of Wyoming, 1000 E. University Ave., Laramie, Wyoming
| | - Philip T Edeen
- Department of Molecular Biology, College of Agriculture, Life Sciences and Natural Resources, University of Wyoming, 1000 E. University Ave., Laramie, Wyoming
| | - David S Fay
- Department of Molecular Biology, College of Agriculture, Life Sciences and Natural Resources, University of Wyoming, 1000 E. University Ave., Laramie, Wyoming
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6
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Hall AE, Klompstra D, Nance J. C. elegans Afadin is required for epidermal morphogenesis and functionally interfaces with the cadherin-catenin complex and RhoGAP PAC-1/ARHGAP21. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.28.551013. [PMID: 37546884 PMCID: PMC10402129 DOI: 10.1101/2023.07.28.551013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/08/2023]
Abstract
During epithelial morphogenesis, the apical junctions connecting cells must remodel as cells change shape and make new connections with their neighbors. In the C. elegans embryo, new apical junctions form when epidermal cells migrate and seal with one another to encase the embryo in skin ('ventral enclosure'), and junctions remodel when epidermal cells change shape to squeeze the embryo into a worm shape ('elongation'). The junctional cadherin-catenin complex (CCC), which links epithelial cells to each other and to cortical actomyosin, is essential for C. elegans epidermal morphogenesis. RNAi genetic enhancement screens have identified several proteins that interact with the CCC to promote epidermal morphogenesis, including the scaffolding protein Afadin (AFD-1), whose depletion alone results in only minor morphogenesis defects. Here, by creating a null mutation in afd-1 , we show that afd-1 provides a significant contribution to ventral enclosure and elongation on its own. Unexpectedly, we find that afd-1 mutant phenotypes are strongly modified by diet, revealing a previously unappreciated maternal nutritional input to morphogenesis. We identify functional interactions between AFD-1 and the CCC by demonstrating that E-cadherin is required for the polarized distribution of AFD-1 to cell contact sites in early embryos. Finally, we show that afd-1 promotes the enrichment of polarity regulator and CCC-interacting protein PAC-1/ARHGAP21 to cell contact sites, and identify genetic interactions suggesting that afd-1 and pac-1 regulate epidermal morphogenesis at least in part through parallel mechanisms. Our findings reveal that C. elegans AFD-1 makes a significant contribution to epidermal morphogenesis and functionally interfaces with core and associated CCC proteins.
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7
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Scott H, Dong L, Stevenson A, MacDonald AI, Srinivasan S, Massimi P, Banks L, Martin PE, Johnstone SR, Graham SV. The human discs large protein 1 interacts with and maintains connexin 43 at the plasma membrane in keratinocytes. J Cell Sci 2023; 136:jcs259984. [PMID: 37288673 PMCID: PMC10309592 DOI: 10.1242/jcs.259984] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 04/21/2023] [Indexed: 05/10/2023] Open
Abstract
Gap junction channels, composed of connexins, allow direct cell-to-cell communication. Connexin 43 (Cx43; also known as GJA1) is widely expressed in tissues, including the epidermis. In a previous study of human papillomavirus-positive cervical epithelial tumour cells, we identified Cx43 as a binding partner of the human homologue of Drosophila Discs large (Dlg1; also known as SAP97). Dlg1 is a member of the membrane associated-guanylate kinase (MAGUK) scaffolding protein family, which is known to control cell shape and polarity. Here, we show that Cx43 also interacts with Dlg1 in uninfected keratinocytes in vitro and in keratinocytes, dermal cells and adipocytes in normal human epidermis in vivo. Depletion of Dlg1 in keratinocytes did not alter Cx43 transcription but was associated with a reduction in Cx43 protein levels. Reduced Dlg1 levels in keratinocytes resulted in a reduction in Cx43 at the plasma membrane with a concomitant reduction in gap junctional intercellular communication and relocation of Cx43 to the Golgi compartment. Our data suggest a key role for Dlg1 in maintaining Cx43 at the plasma membrane in keratinocytes.
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Affiliation(s)
- Harry Scott
- MRC-University of Glasgow Centre for Virus Research, School of Infection and Immunity, College of Medical Veterinary and Life Sciences, University of Glasgow, Garscube Estate, Glasgow G61 1QH, UK
| | - Li Dong
- MRC-University of Glasgow Centre for Virus Research, School of Infection and Immunity, College of Medical Veterinary and Life Sciences, University of Glasgow, Garscube Estate, Glasgow G61 1QH, UK
| | - Andrew Stevenson
- MRC-University of Glasgow Centre for Virus Research, School of Infection and Immunity, College of Medical Veterinary and Life Sciences, University of Glasgow, Garscube Estate, Glasgow G61 1QH, UK
| | - Alasdair I. MacDonald
- MRC-University of Glasgow Centre for Virus Research, School of Infection and Immunity, College of Medical Veterinary and Life Sciences, University of Glasgow, Garscube Estate, Glasgow G61 1QH, UK
| | - Sharmila Srinivasan
- Translation Research Platform for Veterinary Biologicals, Chennai, Tamil Nadu, India
| | - Paola Massimi
- International Centre for Genetic Engineering and Biotechnology, Trieste, Italy
| | - Lawrence Banks
- International Centre for Genetic Engineering and Biotechnology, Trieste, Italy
| | - Patricia E. Martin
- Department of Biological and Biomedical Sciences, School of Health and Life Sciences, Glasgow Caledonian University, Glasgow G4 0BA, UK
| | - Scott R. Johnstone
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Center for Vascular and Heart Research, Virginia Tech, Roanoke VA 24016, USA
| | - Sheila V. Graham
- MRC-University of Glasgow Centre for Virus Research, School of Infection and Immunity, College of Medical Veterinary and Life Sciences, University of Glasgow, Garscube Estate, Glasgow G61 1QH, UK
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8
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Naturale VF, Pickett MA, Feldman JL. Context matters: Lessons in epithelial polarity from the Caenorhabditis elegans intestine and other tissues. Curr Top Dev Biol 2023; 154:37-71. [PMID: 37100523 DOI: 10.1016/bs.ctdb.2023.02.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/28/2023]
Abstract
Epithelia are tissues with diverse morphologies and functions across metazoans, ranging from vast cell sheets encasing internal organs to internal tubes facilitating nutrient uptake, all of which require establishment of apical-basolateral polarity axes. While all epithelia tend to polarize the same components, how these components are deployed to drive polarization is largely context-dependent and likely shaped by tissue-specific differences in development and ultimate functions of polarizing primordia. The nematode Caenorhabditis elegans (C. elegans) offers exceptional imaging and genetic tools and possesses unique epithelia with well-described origins and roles, making it an excellent model to investigate polarity mechanisms. In this review, we highlight the interplay between epithelial polarization, development, and function by describing symmetry breaking and polarity establishment in a particularly well-characterized epithelium, the C. elegans intestine. We compare intestinal polarization to polarity programs in two other C. elegans epithelia, the pharynx and epidermis, correlating divergent mechanisms with tissue-specific differences in geometry, embryonic environment, and function. Together, we emphasize the importance of investigating polarization mechanisms against the backdrop of tissue-specific contexts, while also underscoring the benefits of cross-tissue comparisons of polarity.
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Affiliation(s)
- Victor F Naturale
- Department of Biology, Stanford University, Stanford, CA, United States
| | - Melissa A Pickett
- Department of Biology, Stanford University, Stanford, CA, United States; Department of Biological Sciences, San José State University, San José, CA, United States
| | - Jessica L Feldman
- Department of Biology, Stanford University, Stanford, CA, United States.
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9
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Brunet T, Booth DS. Cell polarity in the protist-to-animal transition. Curr Top Dev Biol 2023; 154:1-36. [PMID: 37100515 DOI: 10.1016/bs.ctdb.2023.03.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/08/2023]
Abstract
A signature feature of the animal kingdom is the presence of epithelia: sheets of polarized cells that both insulate the organism from its environment and mediate interactions with it. Epithelial cells display a marked apico-basal polarity, which is highly conserved across the animal kingdom, both in terms of morphology and of molecular regulators. How did this architecture first evolve? Although the last eukaryotic common ancestor almost certainly possessed a simple form of apico-basal polarity (marked by the presence of one or several flagella at a single cellular pole), comparative genomics and evolutionary cell biology reveal that the polarity regulators of animal epithelial cells have a surprisingly complex and stepwise evolutionary history. Here, we retrace their evolutionary assembly. We suggest that the "polarity network" that polarized animal epithelial cells evolved by integration of initially independent cellular modules that evolved at distinct steps of our evolutionary ancestry. The first module dates back to the last common ancestor of animals and amoebozoans and involved Par1, extracellular matrix proteins, and the integrin-mediated adhesion complex. Other regulators, such as Cdc42, Dlg, Par6 and cadherins evolved in ancient unicellular opisthokonts, and might have first been involved in F-actin remodeling and filopodial dynamics. Finally, the bulk of "polarity proteins" as well as specialized adhesion complexes evolved in the metazoan stem-line, in concert with the newly evolved intercellular junctional belts. Thus, the polarized architecture of epithelia can be understood as a palimpsest of components of distinct histories and ancestral functions, which have become tightly integrated in animal tissues.
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10
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Pickett MA, Sallee MD, Cote L, Naturale VF, Akpinaroglu D, Lee J, Shen K, Feldman JL. Separable mechanisms drive local and global polarity establishment in the Caenorhabditiselegans intestinal epithelium. Development 2022; 149:dev200325. [PMID: 36264257 PMCID: PMC9845746 DOI: 10.1242/dev.200325] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 10/06/2022] [Indexed: 11/17/2022]
Abstract
Apico-basolateral polarization is essential for epithelial cells to function as selective barriers and transporters, and to provide mechanical resilience to organs. Epithelial polarity is established locally, within individual cells to establish distinct apical, junctional and basolateral domains, and globally, within a tissue where cells coordinately orient their apico-basolateral axes. Using live imaging of endogenously tagged proteins and tissue-specific protein depletion in the Caenorhabditiselegans embryonic intestine, we found that local and global polarity establishment are temporally and genetically separable. Local polarity is initiated prior to global polarity and is robust to perturbation. PAR-3 is required for global polarization across the intestine but local polarity can arise in its absence, as small groups of cells eventually established polarized domains in PAR-3-depleted intestines in a HMR-1 (E-cadherin)-dependent manner. Despite the role of PAR-3 in localizing PKC-3 to the apical surface, we additionally found that PAR-3 and PKC-3/aPKC have distinct roles in the establishment and maintenance of local and global polarity. Taken together, our results indicate that different mechanisms are required for local and global polarity establishment in vivo.
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Affiliation(s)
- Melissa A. Pickett
- Department of Biology, Stanford University, Stanford, CA 94305, USA
- Department of Biological Sciences, San Jose State University, San Jose, CA 95112, USA
| | - Maria D. Sallee
- Department of Biology, Stanford University, Stanford, CA 94305, USA
| | - Lauren Cote
- Department of Biology, Stanford University, Stanford, CA 94305, USA
| | | | | | - Joo Lee
- Department of Biology, Stanford University, Stanford, CA 94305, USA
| | - Kang Shen
- Department of Biology, Stanford University, Stanford, CA 94305, USA
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11
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Sepers JJ, Verstappen NHM, Vo AA, Ragle JM, Ruijtenberg S, Ward JD, Boxem M. The mIAA7 degron improves auxin-mediated degradation in Caenorhabditiselegans. G3 (BETHESDA, MD.) 2022; 12:jkac222. [PMID: 36029236 PMCID: PMC9526053 DOI: 10.1093/g3journal/jkac222] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Accepted: 08/15/2022] [Indexed: 04/08/2023]
Abstract
Auxin-inducible degradation is a powerful tool for the targeted degradation of proteins with spatiotemporal control. One limitation of the auxin-inducible degradation system is that not all proteins are degraded efficiently. Here, we demonstrate that an alternative degron sequence, termed mIAA7, improves the efficiency of degradation in Caenorhabditiselegans, as previously reported in human cells. We tested the depletion of a series of proteins with various subcellular localizations in different tissue types and found that the use of the mIAA7 degron resulted in faster depletion kinetics for 5 out of 6 proteins tested. The exception was the nuclear protein HIS-72, which was depleted with similar efficiency as with the conventional AID* degron sequence. The mIAA7 degron also increased the leaky degradation for 2 of the tested proteins. To overcome this problem, we combined the mIAA7 degron with the C. elegans AID2 system, which resulted in complete protein depletion without detectable leaky degradation. Finally, we show that the degradation of ERM-1, a highly stable protein that is challenging to deplete, could be improved further by using multiple mIAA7 degrons. Taken together, the mIAA7 degron further increases the power and applicability of the auxin-inducible degradation system. To facilitate the generation of mIAA7-tagged proteins using CRISPR/Cas9 genome engineering, we generated a toolkit of plasmids for the generation of dsDNA repair templates by PCR.
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Affiliation(s)
- Jorian J Sepers
- Division of Developmental Biology, Institute of Biodynamics and Biocomplexity, Department of Biology, Faculty of Science, Utrecht University, 3584 CH Utrecht, The Netherlands
| | - Noud H M Verstappen
- Division of Developmental Biology, Institute of Biodynamics and Biocomplexity, Department of Biology, Faculty of Science, Utrecht University, 3584 CH Utrecht, The Netherlands
| | - An A Vo
- Department of Molecular, Cell, and Developmental Biology, University of California-Santa Cruz, Santa Cruz, CA 95064, USA
| | - James Matthew Ragle
- Department of Molecular, Cell, and Developmental Biology, University of California-Santa Cruz, Santa Cruz, CA 95064, USA
| | - Suzan Ruijtenberg
- Division of Developmental Biology, Institute of Biodynamics and Biocomplexity, Department of Biology, Faculty of Science, Utrecht University, 3584 CH Utrecht, The Netherlands
| | - Jordan D Ward
- Department of Molecular, Cell, and Developmental Biology, University of California-Santa Cruz, Santa Cruz, CA 95064, USA
| | - Mike Boxem
- Division of Developmental Biology, Institute of Biodynamics and Biocomplexity, Department of Biology, Faculty of Science, Utrecht University, 3584 CH Utrecht, The Netherlands
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12
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Tocchini C, Rohner M, Guerard L, Ray P, Von Stetina SE, Mango SE. Translation-dependent mRNA localization to Caenorhabditis elegans adherens junctions. Development 2021; 148:273751. [PMID: 34846063 PMCID: PMC8722394 DOI: 10.1242/dev.200027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 11/08/2021] [Indexed: 11/27/2022]
Abstract
mRNA localization is an evolutionarily widespread phenomenon that can facilitate subcellular protein targeting. Extensive work has focused on mRNA targeting through ‘zip-codes’ within untranslated regions (UTRs), whereas much less is known about translation-dependent cues. Here, we examine mRNA localization in Caenorhabditis elegans embryonic epithelia. From an smFISH-based survey, we identified mRNAs associated with the cell membrane or cortex, and with apical junctions in a stage- and cell type-specific manner. Mutational analyses for one of these transcripts, dlg-1/discs large, revealed that it relied on a translation-dependent process and did not require its 5′ or 3′ UTRs. We suggest a model in which dlg-1 transcripts are co-translationally localized with the nascent protein: first the translating complex goes to the cell membrane using sequences located at the C-terminal/3′ end, and then apically using N-terminal/5′ sequences. These studies identify a translation-based process for mRNA localization within developing epithelia and determine the necessary cis-acting sequences for dlg-1 mRNA targeting. Summary: An smFISH-based survey identifies a subset of mRNAs encoding junctional components that localize at or in proximity to the adherens junction through a translation-dependent mechanism.
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Affiliation(s)
| | - Michèle Rohner
- Biozentrum, University of Basel, 4056 Basel, Switzerland
| | | | - Poulomi Ray
- Cell, Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | | | - Susan E Mango
- Biozentrum, University of Basel, 4056 Basel, Switzerland
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13
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Lehmann C, Pohl C. A Maternal-Effect Toxin Affects Epithelial Differentiation and Tissue Mechanics in Caenorhabditis elegans. Front Cell Dev Biol 2021; 9:743496. [PMID: 34722524 PMCID: PMC8551626 DOI: 10.3389/fcell.2021.743496] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2021] [Accepted: 09/21/2021] [Indexed: 11/13/2022] Open
Abstract
Selfish genetic elements that act as post-segregation distorters cause lethality in non-carrier individuals after fertilization. Two post-segregation distorters have been previously identified in Caenorhabditis elegans, the peel-1/zeel-1 and the sup-35/pha-1 elements. These elements seem to act as modification-rescue systems, also called toxin/antidote pairs. Here we show that the maternal-effect toxin/zygotic antidote pair sup-35/pha-1 is required for proper expression of apical junction (AJ) components in epithelia and that sup-35 toxicity increases when pathways that establish and maintain basal epithelial characteristics, die-1, elt-1, lin-26, and vab-10, are compromised. We demonstrate that pha-1(e2123) embryos, which lack the antidote, are defective in epidermal morphogenesis and frequently fail to elongate. Moreover, seam cells are frequently misshaped and mispositioned and cell bond tension is reduced in pha-1(e2123) embryos, suggesting altered tissue material properties in the epidermis. Several aspects of this phenotype can also be induced in wild-type embryos by exerting mechanical stress through uniaxial loading. Seam cell shape, tissue mechanics, and elongation can be restored in pha-1(e2123) embryos if expression of the AJ molecule DLG-1/Discs large is reduced. Thus, our experiments suggest that maternal-effect toxicity disrupts proper development of the epidermis which involves distinct transcriptional regulators and AJ components.
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Affiliation(s)
- Christina Lehmann
- Buchmann Institute for Molecular Life Sciences and Institute of Biochemistry II, Medical Faculty, Goethe University, Frankfurt, Germany
| | - Christian Pohl
- Buchmann Institute for Molecular Life Sciences and Institute of Biochemistry II, Medical Faculty, Goethe University, Frankfurt, Germany
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14
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Sharp KA, Khoury MJ, Wirtz-Peitz F, Bilder D. Evidence for a nuclear role for Drosophila Dlg as a regulator of the NURF complex. Mol Biol Cell 2021; 32:ar23. [PMID: 34495684 PMCID: PMC8693970 DOI: 10.1091/mbc.e21-04-0187] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Scribble (Scrib), Discs-large (Dlg), and Lethal giant larvae (Lgl) are basolateral regulators of epithelial polarity and tumor suppressors whose molecular mechanisms of action remain unclear. We used proximity biotinylation to identify proteins localized near Dlg in the Drosophila wing imaginal disc epithelium. In addition to expected membrane- and cytoskeleton-associated protein classes, nuclear proteins were prevalent in the resulting mass spectrometry dataset, including all four members of the nucleosome remodeling factor (NURF) chromatin remodeling complex. Subcellular fractionation demonstrated a nuclear pool of Dlg and proximity ligation confirmed its position near the NURF complex. Genetic analysis showed that NURF activity is also required for the overgrowth of dlg tumors, and this growth suppression correlated with a reduction in Hippo pathway gene expression. Together, these data suggest a nuclear role for Dlg in regulating chromatin and transcription through a more direct mechanism than previously thought.
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Affiliation(s)
- Katherine A Sharp
- Department of Molecular and Cell Biology, University of California-Berkeley, Berkeley CA 94720
| | - Mark J Khoury
- Department of Molecular and Cell Biology, University of California-Berkeley, Berkeley CA 94720
| | | | - David Bilder
- Department of Molecular and Cell Biology, University of California-Berkeley, Berkeley CA 94720
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15
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Cordova-Burgos L, Patel FB, Soto MC. E-Cadherin/HMR-1 Membrane Enrichment Is Polarized by WAVE-Dependent Branched Actin. J Dev Biol 2021; 9:19. [PMID: 34067000 PMCID: PMC8162361 DOI: 10.3390/jdb9020019] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Revised: 04/28/2021] [Accepted: 05/04/2021] [Indexed: 12/27/2022] Open
Abstract
Polarized epithelial cells adhere to each other at apical junctions that connect to the apical F-actin belt. Regulated remodeling of apical junctions supports morphogenesis, while dysregulated remodeling promotes diseases such as cancer. We have documented that branched actin regulator, WAVE, and apical junction protein, Cadherin, assemble together in developing C. elegans embryonic junctions. If WAVE is missing in embryonic epithelia, too much Cadherin assembles at apical membranes, and yet apical F-actin is reduced, suggesting the excess Cadherin is not fully functional. We proposed that WAVE supports apical junctions by regulating the dynamic accumulation of Cadherin at membranes. To test this model, here we examine if WAVE is required for Cadherin membrane enrichment and apical-basal polarity in a maturing epithelium, the post-embryonic C. elegans intestine. We find that larval and adult intestines have distinct apicobasal populations of Cadherin, each with distinct dependence on WAVE branched actin. In vivo imaging shows that loss of WAVE components alters post-embryonic E-cadherin membrane enrichment, especially at apicolateral regions, and alters the lateral membrane. Analysis of a biosensor for PI(4,5)P2 suggests loss of WAVE or Cadherin alters the polarity of the epithelial membrane. EM (electron microscopy) illustrates lateral membrane changes including separations. These findings have implications for understanding how mutations in WAVE and Cadherin may alter cell polarity.
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Affiliation(s)
| | | | - Martha C. Soto
- Department of Pathology and Laboratory Medicine, Rutgers—RWJMS, Piscataway, NJ 08854, USA; (L.C.-B.); (F.B.P.)
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16
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Network analysis in aged C. elegans reveals candidate regulatory genes of ageing. Biogerontology 2021; 22:345-367. [PMID: 33871732 DOI: 10.1007/s10522-021-09920-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Accepted: 03/30/2021] [Indexed: 10/21/2022]
Abstract
Ageing is a biological process guided by genetic and environmental factors that ultimately lead to adverse outcomes for organismal lifespan and healthspan. Determination of molecular pathways that are affected with age and increase disease susceptibility is crucial. The gene expression profile of the ideal ageing model, namely the nematode Caenorhabditis elegans mapped with the microarray technology initially led to the identification of age-dependent gene expression alterations that characterize the nematode's ageing process. The list of differentially expressed genes was then utilized to construct a network of molecular interactions with their first neighbors/interactors using the interactions listed in the WormBase database. The subsequent network analysis resulted in the unbiased selection of 110 candidate genes, among which well-known ageing regulators appeared. More importantly, our approach revealed candidates that have never been linked to ageing before, thus suggesting promising potential targets/ageing regulators.
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17
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Jud MC, Lowry J, Padilla T, Clifford E, Yang Y, Fennell F, Miller AK, Hamill D, Harvey AM, Avila-Zavala M, Shao H, Nguyen Tran N, Bao Z, Bowerman B. A genetic screen for temperature-sensitive morphogenesis-defective Caenorhabditis elegans mutants. G3-GENES GENOMES GENETICS 2021; 11:6169531. [PMID: 33713117 PMCID: PMC8133775 DOI: 10.1093/g3journal/jkab026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 01/18/2021] [Indexed: 11/21/2022]
Abstract
Morphogenesis involves coordinated cell migrations and cell shape changes that generate tissues and organs, and organize the body plan. Cell adhesion and the cytoskeleton are important for executing morphogenesis, but their regulation remains poorly understood. As genes required for embryonic morphogenesis may have earlier roles in development, temperature-sensitive embryonic-lethal mutations are useful tools for investigating this process. From a collection of ∼200 such Caenorhabditis elegans mutants, we have identified 17 that have highly penetrant embryonic morphogenesis defects after upshifts from the permissive to the restrictive temperature, just prior to the cell shape changes that mediate elongation of the ovoid embryo into a vermiform larva. Using whole genome sequencing, we identified the causal mutations in seven affected genes. These include three genes that have roles in producing the extracellular matrix, which is known to affect the morphogenesis of epithelial tissues in multicellular organisms: the rib-1 and rib-2 genes encode glycosyltransferases, and the emb-9 gene encodes a collagen subunit. We also used live imaging to characterize epidermal cell shape dynamics in one mutant, or1219ts, and observed cell elongation defects during dorsal intercalation and ventral enclosure that may be responsible for the body elongation defects. These results indicate that our screen has identified factors that influence morphogenesis and provides a platform for advancing our understanding of this fundamental biological process.
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Affiliation(s)
- Molly C Jud
- Institute of Molecular Biology, University of Oregon, Eugene, OR, 97402, USA
| | - Josh Lowry
- Institute of Molecular Biology, University of Oregon, Eugene, OR, 97402, USA
| | - Thalia Padilla
- Institute of Molecular Biology, University of Oregon, Eugene, OR, 97402, USA
| | - Erin Clifford
- Institute of Molecular Biology, University of Oregon, Eugene, OR, 97402, USA
| | - Yuqi Yang
- Institute of Molecular Biology, University of Oregon, Eugene, OR, 97402, USA
| | - Francesca Fennell
- Institute of Molecular Biology, University of Oregon, Eugene, OR, 97402, USA
| | - Alexander K Miller
- Institute of Molecular Biology, University of Oregon, Eugene, OR, 97402, USA
| | - Danielle Hamill
- Department of Zoology, Ohio Wesleyan University, Delaware, OH, 43015, USA
| | - Austin M Harvey
- Institute of Molecular Biology, University of Oregon, Eugene, OR, 97402, USA
| | - Martha Avila-Zavala
- Institute of Molecular Biology, University of Oregon, Eugene, OR, 97402, USA
| | - Hong Shao
- Developmental Biology Program, Sloan Kettering Institute, New York, NY, 10065, USA
| | - Nhan Nguyen Tran
- Developmental Biology Program, Sloan Kettering Institute, New York, NY, 10065, USA
| | - Zhirong Bao
- Developmental Biology Program, Sloan Kettering Institute, New York, NY, 10065, USA
| | - Bruce Bowerman
- Institute of Molecular Biology, University of Oregon, Eugene, OR, 97402, USA
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18
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Chytła A, Gajdzik-Nowak W, Olszewska P, Biernatowska A, Sikorski AF, Czogalla A. Not Just Another Scaffolding Protein Family: The Multifaceted MPPs. Molecules 2020; 25:molecules25214954. [PMID: 33114686 PMCID: PMC7662862 DOI: 10.3390/molecules25214954] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 10/16/2020] [Accepted: 10/20/2020] [Indexed: 01/03/2023] Open
Abstract
Membrane palmitoylated proteins (MPPs) are a subfamily of a larger group of multidomain proteins, namely, membrane-associated guanylate kinases (MAGUKs). The ubiquitous expression and multidomain structure of MPPs provide the ability to form diverse protein complexes at the cell membranes, which are involved in a wide range of cellular processes, including establishing the proper cell structure, polarity and cell adhesion. The formation of MPP-dependent complexes in various cell types seems to be based on similar principles, but involves members of different protein groups, such as 4.1-ezrin-radixin-moesin (FERM) domain-containing proteins, polarity proteins or other MAGUKs, showing their multifaceted nature. In this review, we discuss the function of the MPP family in the formation of multiple protein complexes. Notably, we depict their significant role for cell physiology, as the loss of interactions between proteins involved in the complex has a variety of negative consequences. Moreover, based on recent studies concerning the mechanism of membrane raft formation, we shed new light on a possible role played by MPPs in lateral membrane organization.
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Affiliation(s)
- Agnieszka Chytła
- Department of Cytobiochemistry, Faculty of Biotechnology, University of Wroclaw, 50-383 Wroclaw, Poland; (A.C.); (W.G.-N.); (P.O.); (A.B.)
| | - Weronika Gajdzik-Nowak
- Department of Cytobiochemistry, Faculty of Biotechnology, University of Wroclaw, 50-383 Wroclaw, Poland; (A.C.); (W.G.-N.); (P.O.); (A.B.)
| | - Paulina Olszewska
- Department of Cytobiochemistry, Faculty of Biotechnology, University of Wroclaw, 50-383 Wroclaw, Poland; (A.C.); (W.G.-N.); (P.O.); (A.B.)
| | - Agnieszka Biernatowska
- Department of Cytobiochemistry, Faculty of Biotechnology, University of Wroclaw, 50-383 Wroclaw, Poland; (A.C.); (W.G.-N.); (P.O.); (A.B.)
| | - Aleksander F. Sikorski
- Research and Development Center, Regional Specialist Hospital, Kamieńskiego 73a, 51-154 Wroclaw, Poland;
| | - Aleksander Czogalla
- Department of Cytobiochemistry, Faculty of Biotechnology, University of Wroclaw, 50-383 Wroclaw, Poland; (A.C.); (W.G.-N.); (P.O.); (A.B.)
- Correspondence: ; Tel.: +48-71375-6356
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19
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Egge N, Arneaud SLB, Wales P, Mihelakis M, McClendon J, Fonseca RS, Savelle C, Gonzalez I, Ghorashi A, Yadavalli S, Lehman WJ, Mirzaei H, Douglas PM. Age-Onset Phosphorylation of a Minor Actin Variant Promotes Intestinal Barrier Dysfunction. Dev Cell 2020; 51:587-601.e7. [PMID: 31794717 DOI: 10.1016/j.devcel.2019.11.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Revised: 09/17/2019] [Accepted: 11/03/2019] [Indexed: 12/28/2022]
Abstract
Age-associated decay of intercellular interactions impairs the cells' capacity to tightly associate within tissues and form a functional barrier. This barrier dysfunction compromises organ physiology and contributes to systemic failure. The actin cytoskeleton represents a key determinant in maintaining tissue architecture. Yet, it is unclear how age disrupts the actin cytoskeleton and how this, in turn, promotes mortality. Here, we show that an uncharacterized phosphorylation of a low-abundant actin variant, ACT-5, compromises integrity of the C. elegans intestinal barrier and accelerates pathogenesis. Age-related loss of the heat-shock transcription factor, HSF-1, disrupts the JUN kinase and protein phosphatase I equilibrium which increases ACT-5 phosphorylation within its troponin binding site. Phosphorylated ACT-5 accelerates decay of the intestinal subapical terminal web and impairs its interactions with cell junctions. This compromises barrier integrity, promotes pathogenesis, and drives mortality. Thus, we provide the molecular mechanism by which age-associated loss of specialized actin networks impacts tissue integrity.
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Affiliation(s)
- Nathan Egge
- Department of Molecular Biology, UT Southwestern Medical Center, Dallas, TX 75390, USA; Medical Scientist Training Program, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Sonja L B Arneaud
- Department of Molecular Biology, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Pauline Wales
- Department of Molecular Biology, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Melina Mihelakis
- Department of Molecular Biology, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Jacob McClendon
- Department of Molecular Biology, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Rene Solano Fonseca
- Department of Molecular Biology, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Charles Savelle
- Department of Molecular Biology, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Ian Gonzalez
- Department of Molecular Biology, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Atossa Ghorashi
- Department of Molecular Biology, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | | | - William J Lehman
- Department of Structural Biology, Boston University, Boston, MA 02118, USA
| | - Hamid Mirzaei
- Department of Biochemistry, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Peter M Douglas
- Department of Molecular Biology, UT Southwestern Medical Center, Dallas, TX 75390, USA; Hamon Center for Regenerative Science and Medicine, UT Southwestern Medical Center, Dallas, TX 75390, USA.
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20
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Bonello TT, Choi W, Peifer M. Scribble and Discs-large direct initial assembly and positioning of adherens junctions during the establishment of apical-basal polarity. Development 2019; 146:dev.180976. [PMID: 31628110 DOI: 10.1242/dev.180976] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Accepted: 10/14/2019] [Indexed: 01/05/2023]
Abstract
Apical-basal polarity is a fundamental property of animal tissues. Drosophila embryos provide an outstanding model for defining mechanisms that initiate and maintain polarity. Polarity is initiated during cellularization, when cell-cell adherens junctions are positioned at the future boundary of apical and basolateral domains. Polarity maintenance then involves complementary and antagonistic interplay between apical and basal polarity complexes. The Scribble/Dlg module is well-known for promoting basolateral identity during polarity maintenance. Here, we report a surprising role for Scribble/Dlg in polarity initiation, placing it near the top of the network-positioning adherens junctions. Scribble and Dlg are enriched in nascent adherens junctions, are essential for adherens junction positioning and supermolecular assembly, and also play a role in basal junction assembly. We test the hypotheses for the underlying mechanisms, exploring potential effects on protein trafficking, cytoskeletal polarity or Par-1 localization/function. Our data suggest that the Scribble/Dlg module plays multiple roles in polarity initiation. Different domains of Scribble contribute to these distinct roles. Together, these data reveal novel roles for Scribble/Dlg as master scaffolds regulating assembly of distinct junctional complexes at different times and places.
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Affiliation(s)
- Teresa T Bonello
- Department of Biology, University of North Carolina at Chapel Hill, CB#3280, Chapel Hill, NC 27599-3280, USA
| | - Wangsun Choi
- Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Mark Peifer
- Department of Biology, University of North Carolina at Chapel Hill, CB#3280, Chapel Hill, NC 27599-3280, USA .,Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.,Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
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21
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Porter AP, White GRM, Mack NA, Malliri A. The interaction between CASK and the tumour suppressor Dlg1 regulates mitotic spindle orientation in mammalian epithelia. J Cell Sci 2019; 132:jcs230086. [PMID: 31289196 PMCID: PMC6679578 DOI: 10.1242/jcs.230086] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Accepted: 06/14/2019] [Indexed: 12/30/2022] Open
Abstract
Oriented cell divisions are important for the formation of normal epithelial structures. Dlg1, a tumour suppressor, is required for mitotic spindle orientation in Drosophila epithelia and chick neuroepithelia, but how Dlg1 is localised to the membrane and its importance in mammalian epithelia are unknown. We show that Dlg1 is required in non-transformed mammalian epithelial cells for oriented cell divisions and normal lumen formation. We demonstrate that the MAGUK protein CASK, a membrane-associated scaffold, is the factor responsible for Dlg1 membrane localisation during spindle orientation, thereby identifying a new cellular function for CASK. Depletion of CASK leads to misoriented divisions in 3D, and to the formation of multilumen structures in cultured kidney and breast epithelial cells. Blocking the CASK-Dlg1 interaction with an interfering peptide, or by deletion of the CASK-interaction domain of Dlg1, disrupts spindle orientation and causes multilumen formation. We show that the CASK-Dlg1 interaction is important for localisation of the canonical LGN-NuMA complex known to be required for spindle orientation. These results establish the importance of the CASK-Dlg1 interaction in oriented cell division and epithelial integrity.This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Andrew P Porter
- Cell Signalling Group, Cancer Research UK Manchester Institute, The University of Manchester, Alderley Park, Macclesfield SK10 4TG, UK
| | - Gavin R M White
- Cell Signalling Group, Cancer Research UK Manchester Institute, The University of Manchester, Alderley Park, Macclesfield SK10 4TG, UK
| | - Natalie A Mack
- Cell Signalling Group, Cancer Research UK Manchester Institute, The University of Manchester, Alderley Park, Macclesfield SK10 4TG, UK
| | - Angeliki Malliri
- Cell Signalling Group, Cancer Research UK Manchester Institute, The University of Manchester, Alderley Park, Macclesfield SK10 4TG, UK
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22
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Fan L, Kovacevic I, Heiman MG, Bao Z. A multicellular rosette-mediated collective dendrite extension. eLife 2019; 8:38065. [PMID: 30767892 PMCID: PMC6400498 DOI: 10.7554/elife.38065] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Accepted: 02/14/2019] [Indexed: 12/16/2022] Open
Abstract
Coordination of neurite morphogenesis with surrounding tissues is crucial to the establishment of neural circuits, but the underlying cellular and molecular mechanisms remain poorly understood. We show that neurons in a C. elegans sensory organ, called the amphid, undergo a collective dendrite extension to form the sensory nerve. The amphid neurons first assemble into a multicellular rosette. The vertex of the rosette, which becomes the dendrite tips, is attached to the anteriorly migrating epidermis and carried to the sensory depression, extruding the dendrites away from the neuronal cell bodies. Multiple adhesion molecules including DYF-7, SAX-7, HMR-1 and DLG-1 function redundantly in rosette-to-epidermis attachment. PAR-6 is localized to the rosette vertex and dendrite tips, and promotes DYF-7 localization and dendrite extension. Our results suggest a collective mechanism of neurite extension that is distinct from the classical pioneer-follower model and highlight the role of mechanical cues from surrounding tissues in shaping neurites.
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Affiliation(s)
- Li Fan
- Developmental Biology Program, Sloan Kettering Institute, New York, United States
| | - Ismar Kovacevic
- Developmental Biology Program, Sloan Kettering Institute, New York, United States
| | - Maxwell G Heiman
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, United States.,Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, United States
| | - Zhirong Bao
- Developmental Biology Program, Sloan Kettering Institute, New York, United States
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23
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Heppert JK, Pani AM, Roberts AM, Dickinson DJ, Goldstein B. A CRISPR Tagging-Based Screen Reveals Localized Players in Wnt-Directed Asymmetric Cell Division. Genetics 2018; 208:1147-1164. [PMID: 29348144 PMCID: PMC5844328 DOI: 10.1534/genetics.117.300487] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 01/08/2018] [Indexed: 11/18/2022] Open
Abstract
Oriented cell divisions are critical to establish and maintain cell fates and tissue organization. Diverse extracellular and intracellular cues have been shown to provide spatial information for mitotic spindle positioning; however, the molecular mechanisms by which extracellular signals communicate with cells to direct mitotic spindle positioning are largely unknown. In animal cells, oriented cell divisions are often achieved by the localization of force-generating motor protein complexes to discrete cortical domains. Disrupting either these force-generating complexes or proteins that globally affect microtubule stability results in defects in mitotic positioning, irrespective of whether these proteins function as spatial cues for spindle orientation. This poses a challenge to traditional genetic dissection of this process. Therefore, as an alternative strategy to identify key proteins that act downstream of intercellular signaling, we screened the localization of many candidate proteins by inserting fluorescent tags directly into endogenous gene loci, without overexpressing the proteins. We tagged 23 candidate proteins in Caenorhabditis elegans and examined each protein's localization in a well-characterized, oriented cell division in the four-cell-stage embryo. We used cell manipulations and genetic experiments to determine which cells harbor key localized proteins and which signals direct these localizations in vivo We found that Dishevelled and adenomatous polyposis coli homologs are polarized during this oriented cell division in response to a Wnt signal, but two proteins typically associated with mitotic spindle positioning, homologs of NuMA and Dynein, were not detectably polarized. These results suggest an unexpected mechanism for mitotic spindle positioning in this system, they pinpoint key proteins of interest, and they highlight the utility of a screening approach based on analyzing the localization of endogenously tagged proteins.
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Affiliation(s)
- Jennifer K Heppert
- Department of Biology, University of North Carolina at Chapel Hill, North Carolina 27599
| | - Ariel M Pani
- Department of Biology, University of North Carolina at Chapel Hill, North Carolina 27599
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, North Carolina 27599
| | - Allyson M Roberts
- Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, North Carolina 27599
| | - Daniel J Dickinson
- Department of Biology, University of North Carolina at Chapel Hill, North Carolina 27599
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, North Carolina 27599
| | - Bob Goldstein
- Department of Biology, University of North Carolina at Chapel Hill, North Carolina 27599
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, North Carolina 27599
- Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, North Carolina 27599
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24
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Zilberman Y, Abrams J, Anderson DC, Nance J. Cdc42 regulates junctional actin but not cell polarization in the Caenorhabditis elegans epidermis. J Cell Biol 2017; 216:3729-3744. [PMID: 28903999 PMCID: PMC5674880 DOI: 10.1083/jcb.201611061] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Revised: 07/18/2017] [Accepted: 08/15/2017] [Indexed: 12/27/2022] Open
Abstract
During morphogenesis, adherens junctions (AJs) remodel to allow changes in cell shape and position while preserving adhesion. Here, we examine the function of Rho guanosine triphosphatase CDC-42 in AJ formation and regulation during Caenorhabditis elegans embryo elongation, a process driven by asymmetric epidermal cell shape changes. cdc-42 mutant embryos arrest during elongation with epidermal ruptures. Unexpectedly, we find using time-lapse fluorescence imaging that cdc-42 is not required for epidermal cell polarization or junction assembly, but rather is needed for proper junctional actin regulation during elongation. We show that the RhoGAP PAC-1/ARHGAP21 inhibits CDC-42 activity at AJs, and loss of PAC-1 or the interacting linker protein PICC-1/CCDC85A-C blocks elongation in embryos with compromised AJ function. pac-1 embryos exhibit dynamic accumulations of junctional F-actin and an increase in AJ protein levels. Our findings identify a previously unrecognized molecular mechanism for inhibiting junctional CDC-42 to control actin organization and AJ protein levels during epithelial morphogenesis.
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Affiliation(s)
- Yuliya Zilberman
- Helen L. and Martin S. Kimmel Center for Biology and Medicine at the Skirball Institute of Biomolecular Medicine, New York University School of Medicine, New York, NY
| | - Joshua Abrams
- Helen L. and Martin S. Kimmel Center for Biology and Medicine at the Skirball Institute of Biomolecular Medicine, New York University School of Medicine, New York, NY
| | - Dorian C Anderson
- Helen L. and Martin S. Kimmel Center for Biology and Medicine at the Skirball Institute of Biomolecular Medicine, New York University School of Medicine, New York, NY
| | - Jeremy Nance
- Helen L. and Martin S. Kimmel Center for Biology and Medicine at the Skirball Institute of Biomolecular Medicine, New York University School of Medicine, New York, NY .,Department of Cell Biology, New York University School of Medicine, New York, NY
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25
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Von Stetina SE, Liang J, Marnellos G, Mango SE. Temporal regulation of epithelium formation mediated by FoxA, MKLP1, MgcRacGAP, and PAR-6. Mol Biol Cell 2017; 28:2042-2065. [PMID: 28539408 PMCID: PMC5509419 DOI: 10.1091/mbc.e16-09-0644] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Revised: 05/18/2017] [Accepted: 05/18/2017] [Indexed: 12/15/2022] Open
Abstract
During embryo morphogenesis, minor epithelia are generated after, and then form bridges between, major epithelia (e.g., epidermis and gut). In Caenorhabditis elegans, this delay is regulated by four proteins that control production and localization of polarity proteins: the pioneer factor PHA-4/FoxA, kinesin ZEN-4/MKLP1, its partner CYK-4/MgcRacGAP, and PAR-6. To establish the animal body plan, embryos link the external epidermis to the internal digestive tract. In Caenorhabditis elegans, this linkage is achieved by the arcade cells, which form an epithelial bridge between the foregut and epidermis, but little is known about how development of these three epithelia is coordinated temporally. The arcade cell epithelium is generated after the epidermis and digestive tract epithelia have matured, ensuring that both organs can withstand the mechanical stress of embryo elongation; mistiming of epithelium formation leads to defects in morphogenesis. Using a combination of genetic, bioinformatic, and imaging approaches, we find that temporal regulation of the arcade cell epithelium is mediated by the pioneer transcription factor and master regulator PHA-4/FoxA, followed by the cytoskeletal regulator and kinesin ZEN-4/MKLP1 and the polarity protein PAR-6. We show that PHA-4 directly activates mRNA expression of a broad cohort of epithelial genes, including junctional factor dlg-1. Accumulation of DLG-1 protein is delayed by ZEN-4, acting in concert with its binding partner CYK-4/MgcRacGAP. Our structure–function analysis suggests that nuclear and kinesin functions are dispensable, whereas binding to CYK-4 is essential, for ZEN-4 function in polarity. Finally, PAR-6 is necessary to localize polarity proteins such as DLG-1 within adherens junctions and at the apical surface, thereby generating arcade cell polarity. Our results reveal that the timing of a landmark event during embryonic morphogenesis is mediated by the concerted action of four proteins that delay the formation of an epithelial bridge until the appropriate time. In addition, we find that mammalian FoxA associates with many epithelial genes, suggesting that direct regulation of epithelial identity may be a conserved feature of FoxA factors and a contributor to FoxA function in development and cancer.
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Affiliation(s)
- Stephen E Von Stetina
- Department of Molecular and Cellular Biology, Harvard University, Cambridge; MA 02138
| | - Jennifer Liang
- Department of Molecular and Cellular Biology, Harvard University, Cambridge; MA 02138
| | - Georgios Marnellos
- Informatics and Scientific Applications, Science Division, Faculty of Arts and Sciences, Harvard University, Cambridge; MA 02138
| | - Susan E Mango
- Department of Molecular and Cellular Biology, Harvard University, Cambridge; MA 02138
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26
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Waaijers S, Muñoz J, Berends C, Ramalho JJ, Goerdayal SS, Low TY, Zoumaro-Djayoon AD, Hoffmann M, Koorman T, Tas RP, Harterink M, Seelk S, Kerver J, Hoogenraad CC, Bossinger O, Tursun B, van den Heuvel S, Heck AJR, Boxem M. A tissue-specific protein purification approach in Caenorhabditis elegans identifies novel interaction partners of DLG-1/Discs large. BMC Biol 2016; 14:66. [PMID: 27506200 PMCID: PMC4977824 DOI: 10.1186/s12915-016-0286-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Accepted: 07/19/2016] [Indexed: 01/06/2023] Open
Abstract
Background Affinity purification followed by mass spectrometry (AP/MS) is a widely used approach to identify protein interactions and complexes. In multicellular organisms, the accurate identification of protein complexes by AP/MS is complicated by the potential heterogeneity of complexes in different tissues. Here, we present an in vivo biotinylation-based approach for the tissue-specific purification of protein complexes from Caenorhabditis elegans. Tissue-specific biotinylation is achieved by the expression in select tissues of the bacterial biotin ligase BirA, which biotinylates proteins tagged with the Avi peptide. Results We generated N- and C-terminal tags combining GFP with the Avi peptide sequence, as well as four BirA driver lines expressing BirA ubiquitously and specifically in the seam and hyp7 epidermal cells, intestine, or neurons. We validated the ability of our approach to identify bona fide protein interactions by identifying the known LGL-1 interaction partners PAR-6 and PKC-3. Purification of the Discs large protein DLG-1 identified several candidate interaction partners, including the AAA-type ATPase ATAD-3 and the uncharacterized protein MAPH-1.1. We have identified the domains that mediate the DLG-1/ATAD-3 interaction, and show that this interaction contributes to C. elegans development. MAPH-1.1 co-purified specifically with DLG-1 purified from neurons, and shared limited homology with the microtubule-associated protein MAP1A, a known neuronal interaction partner of mammalian DLG4/PSD95. A CRISPR/Cas9-engineered GFP::MAPH-1.1 fusion was broadly expressed and co-localized with microtubules. Conclusions The method we present here is able to purify protein complexes from specific tissues. We uncovered a series of DLG-1 interactors, and conclude that ATAD-3 is a biologically relevant interaction partner of DLG-1. Finally, we conclude that MAPH-1.1 is a microtubule-associated protein of the MAP1 family and a candidate neuron-specific interaction partner of DLG-1. Electronic supplementary material The online version of this article (doi:10.1186/s12915-016-0286-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Selma Waaijers
- Developmental Biology, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands.,Present address: Department of Physiology, Radboud University Medical Center, Geert Grooteplein 26, 6525 GA, Nijmegen, The Netherlands
| | - Javier Muñoz
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands.,Netherlands Proteomics Centre, Padualaan 8, 3584 CH, Utrecht, The Netherlands.,Present address: Proteomics Unit, Spanish National Cancer Research Centre (CNIO), ProteoRed-ISCIII, 28029, Madrid, Spain
| | - Christian Berends
- Developmental Biology, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands
| | - João J Ramalho
- Developmental Biology, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands
| | - Soenita S Goerdayal
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands.,Netherlands Proteomics Centre, Padualaan 8, 3584 CH, Utrecht, The Netherlands
| | - Teck Y Low
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands.,Netherlands Proteomics Centre, Padualaan 8, 3584 CH, Utrecht, The Netherlands
| | - Adja D Zoumaro-Djayoon
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands.,Netherlands Proteomics Centre, Padualaan 8, 3584 CH, Utrecht, The Netherlands
| | - Michael Hoffmann
- Institut für Wissenschaftliche Medizin, D-40591, Düsseldorf, Germany
| | - Thijs Koorman
- Developmental Biology, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands.,Present address: Center for Cancer Research and Department of Pathology, Massachusetts General Hospital and Harvard Medical School Department of Pathology, 149 13th Street, 02129, Charlestown, MA, USA
| | - Roderick P Tas
- Cell Biology, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands
| | - Martin Harterink
- Cell Biology, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands
| | - Stefanie Seelk
- Berlin Institute for Medical Systems Biology (BIMSB), Max Delbrueck Center for Molecular Medicine (MDC) in the Helmholtz Association, Robert-Roessle-Strasse 10, Berlin, 13125, Germany
| | - Jana Kerver
- Developmental Biology, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands
| | - Casper C Hoogenraad
- Cell Biology, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands
| | - Olaf Bossinger
- Molecular Cell Biology, Anatomy I, University of Cologne, D-50937, Cologne, Germany
| | - Baris Tursun
- Berlin Institute for Medical Systems Biology (BIMSB), Max Delbrueck Center for Molecular Medicine (MDC) in the Helmholtz Association, Robert-Roessle-Strasse 10, Berlin, 13125, Germany.
| | - Sander van den Heuvel
- Developmental Biology, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands
| | - Albert J R Heck
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands.,Netherlands Proteomics Centre, Padualaan 8, 3584 CH, Utrecht, The Netherlands
| | - Mike Boxem
- Developmental Biology, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands.
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27
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Jahnel O, Hoffmann B, Merkel R, Bossinger O, Leube RE. Mechanical Probing of the Intermediate Filament-Rich Caenorhabditis Elegans Intestine. Methods Enzymol 2015; 568:681-706. [PMID: 26795489 DOI: 10.1016/bs.mie.2015.08.030] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
It is commonly accepted that intermediate filaments have an important mechanical function. This function relies not only on intrinsic material properties but is also determined by dynamic interactions with other cytoskeletal filament systems, distinct cell adhesion sites, and cellular organelles which are fine-tuned by multiple signaling pathways. While aspects of these properties and processes can be studied in vitro, their full complexity can only be understood in a viable tissue context. Yet, suitable and easily accessible model systems for monitoring tissue mechanics at high precision are rare. We show that the dissected intestine of the genetic model organism Caenorhabditis elegans fulfills this requirement. The 20 intestinal cells, which are arranged in an invariant fashion, are characterized by a dense subapical mesh of intermediate filaments that are attached to the C. elegans apical junction. We present procedures to visualize details of the characteristic intermediate filament-junctional complex arrangement in living animals. We then report on methods to prepare intestines with a fully intact intermediate filament cytoskeleton and detail procedures to assess their viability. A dual micropipette assay is described to measure mechanical properties of the dissected intestine while monitoring the spatial arrangement of the intermediate filament system. Advantages of this approach are (i) the high reproducibility of measurements because of the uniform architecture of the intestine and (ii) the high degree of accessibility allowing not only mechanical manipulation of an intact tissue but also control of culture medium composition and addition of drugs as well as visualization of cell structures. With this method, examination of worms carrying mutations in the intermediate filament system, its interacting partners and its regulators will become feasible.
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Affiliation(s)
- Oliver Jahnel
- Institute of Molecular and Cellular Anatomy, RWTH Aachen University, Aachen, Germany
| | - Bernd Hoffmann
- Institute of Complex Systems, ICS-7: Biomechanics, Jülich, Germany
| | - Rudolf Merkel
- Institute of Complex Systems, ICS-7: Biomechanics, Jülich, Germany
| | - Olaf Bossinger
- Institute of Molecular and Cellular Anatomy, RWTH Aachen University, Aachen, Germany
| | - Rudolf E Leube
- Institute of Molecular and Cellular Anatomy, RWTH Aachen University, Aachen, Germany.
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28
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Proteomic analysis of proteins surrounding occludin and claudin-4 reveals their proximity to signaling and trafficking networks. PLoS One 2015; 10:e0117074. [PMID: 25789658 PMCID: PMC4366163 DOI: 10.1371/journal.pone.0117074] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Accepted: 12/18/2014] [Indexed: 01/15/2023] Open
Abstract
Tight junctions are complex membrane structures that regulate paracellular movement of material across epithelia and play a role in cell polarity, signaling and cytoskeletal organization. In order to expand knowledge of the tight junction proteome, we used biotin ligase (BioID) fused to occludin and claudin-4 to biotinylate their proximal proteins in cultured MDCK II epithelial cells. We then purified the biotinylated proteins on streptavidin resin and identified them by mass spectrometry. Proteins were ranked by relative abundance of recovery by mass spectrometry, placed in functional categories, and compared not only among the N- and C- termini of occludin and the N-terminus of claudin-4, but also with our published inventory of proteins proximal to the adherens junction protein E-cadherin and the tight junction protein ZO-1. When proteomic results were analyzed, the relative distribution among functional categories was similar between occludin and claudin-4 proximal proteins. Apart from already known tight junction- proteins, occludin and claudin-4 proximal proteins were enriched in signaling and trafficking proteins, especially endocytic trafficking proteins. However there were significant differences in the specific proteins comprising the functional categories near each of the tagging proteins, revealing spatial compartmentalization within the junction complex. Taken together, these results expand the inventory of known and unknown proteins at the tight junction to inform future studies of the organization and physiology of this complex structure.
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29
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Von Stetina SE, Mango SE. PAR-6, but not E-cadherin and β-integrin, is necessary for epithelial polarization in C. elegans. Dev Biol 2015; 403:5-14. [PMID: 25773364 DOI: 10.1016/j.ydbio.2015.03.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2014] [Revised: 01/29/2015] [Accepted: 03/04/2015] [Indexed: 10/23/2022]
Abstract
Cell polarity is a fundamental characteristic of epithelial cells. Classical cell biological studies have suggested that establishment and orientation of polarized epithelia depend on outside-in cues that derive from interactions with either neighboring cells or the substratum (Akhtar and Streuli, 2013; Chen and Zhang, 2013; Chung and Andrew, 2008; McNeill et al., 1990; Nejsum and Nelson, 2007; Nelson et al., 2013; Ojakian and Schwimmer, 1994; Wang et al., 1990; Yu et al., 2005). This paradigm has been challenged by examples of epithelia generated in the absence of molecules that mediate cell-cell or cell-matrix interactions, notably E-cadherin and integrins (Baas et al., 2004; Choi et al., 2013; Costa et al., 1998; Harris and Peifer, 2004; Raich et al., 1999; Roote and Zusman, 1995; Vestweber et al., 1985; Williams and Waterston, 1994; Wu et al., 2009). Here we explore an alternative hypothesis, that cadherins and integrins function redundantly to substitute for one another during epithelium formation (Martinez-Rico et al., 2010; Ojakian et al., 2001; Rudkouskaya et al., 2014; Weber et al., 2011). We use C. elegans, which possesses a single E-cadherin (Costa et al., 1998; Hardin et al., 2013; Tepass, 1999) and a single β-integrin (Gettner et al., 1995; Lee et al., 2001), and analyze the arcade cells, which generate an epithelium late in embryogenesis (Portereiko and Mango, 2001; Portereiko et al., 2004), after most maternal factors are depleted. Loss of E-cadherin(HMR-1) in combination with β-integrin(PAT-3) had no impact on the onset or formation of the arcade cell epithelium, nor the epidermis or digestive tract. Moreover, ß-integrin(PAT-3) was not enriched at the basal surface of the arcades, and the candidate PAT-3 binding partner β-laminin(LAM-1) was not detected until after arcade cell polarity was established and exhibited no obvious polarity defect when mutated. Instead, the polarity protein par-6 (Chen and Zhang, 2013; Watts et al., 1996) was required to polarize the arcade cells, and par-6 mutants exhibited mislocalized or absent apical and junctional proteins. We conclude that the arcade cell epithelium polarizes by a PAR-6-mediated pathway that is independent of E-cadherin, β-integrin and β-laminin.
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Affiliation(s)
- Stephen E Von Stetina
- Department of Molecular and Cellular Biology, Harvard University, Boston, MA 02138, USA.
| | - Susan E Mango
- Department of Molecular and Cellular Biology, Harvard University, Boston, MA 02138, USA.
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30
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The PAF1 complex is involved in embryonic epidermal morphogenesis in Caenorhabditis elegans. Dev Biol 2014; 391:43-53. [PMID: 24721716 DOI: 10.1016/j.ydbio.2014.04.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2014] [Revised: 03/29/2014] [Accepted: 04/02/2014] [Indexed: 11/21/2022]
Abstract
The PAF1 complex (PAF1C) is an evolutionarily conserved protein complex involved in transcriptional regulation and chromatin remodeling. How the PAF1C is involved in animal development is still not well understood. Here, we report that, in the nematode Caenorhabditis elegans, the PAF1C is involved in epidermal morphogenesis in late embryogenesis. From an RNAi screen we identified the C. elegans ortholog of a component of the PAF1C, CTR-9, as a gene whose depletion caused various defects during embryonic epidermal morphogenesis, including epidermal cell positioning, ventral enclosure and epidermal elongation. RNAi of orthologs of other four components of the PAF1C (PAFO-1, LEO-1, CDC-73 and RTFO-1) caused similar epidermal defects. In these embryos, whereas the number and cell fate determination of epidermal cells were apparently unaffected, their position and shape were severely disorganized. PAFO-1::mCherry, mCherry::LEO-1 and GFP::RTFO-1 driven by the authentic promoters were detected in the nuclei of a wide range of cells. Nuclear localization of GFP::RTFO-1 was independent of other PAF1C components, while PAFO-1::mCherry and mCherry::LEO-1 dependent on other components except RTFO-1. Epidermis-specific expression of mCherry::LEO-1 rescued embryonic lethality of the leo-1 deletion mutant. Thus, although the PAF1C is universally expressed in C. elegans embryos, its epidermal function is crucial for the viability of this animal.
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Cram EJ. Mechanotransduction in C. elegans morphogenesis and tissue function. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2014; 126:281-316. [PMID: 25081623 DOI: 10.1016/b978-0-12-394624-9.00012-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Mechanobiology is an emerging field that investigates how living cells sense and respond to their physical surroundings. Recent interest in the field has been sparked by the finding that stem cells differentiate along different lineages based on the stiffness of the cell surroundings (Engler et al., 2006), and that metastatic behavior of cancer cells is strongly influenced by the mechanical properties of the surrounding tissue (Kumar and Weaver, 2009). Many questions remain about how cells convert mechanical information, such as viscosity, stiffness of the substrate, or stretch state of the cells, into the biochemical signals that control tissue function. Caenorhabditis elegans researchers are making significant contributions to the understanding of mechanotransduction in vivo. This review summarizes recent insights into the role of mechanical forces in morphogenesis and tissue function. Examples of mechanical regulation across length scales, from the single-celled zygote, to the intercellular coordination that enables cohesive tissue function, to the mechanical influences between tissues, are considered. The power of the C. elegans system as a gene discovery and in vivo quantitative bioimaging platform is enabling an important discoveries in this exciting field.
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Affiliation(s)
- Erin J Cram
- Department of Biology, Northeastern University, Boston, Massachusetts, USA
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32
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Simske JS. Claudins reign: The claudin/EMP/PMP22/γ channel protein family in C. elegans. Tissue Barriers 2013; 1:e25502. [PMID: 24665403 PMCID: PMC3879130 DOI: 10.4161/tisb.25502] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2013] [Revised: 06/19/2013] [Accepted: 06/21/2013] [Indexed: 01/06/2023] Open
Abstract
The claudin family of integral membrane proteins was identified as the major protein component of the tight junctions in all vertebrates. Since their identification, claudins, and their associated pfam00822 superfamily of proteins have been implicated in a wide variety of cellular processes. Claudin homologs have been identified in invertebrates as well, including Drosophila and C. elegans. Recent studies demonstrate that the C. elegans claudins, clc-1-clc- 5, and similar proteins in the greater PMP22/EMP/claudin/voltage-gated calcium channel γ subunit family, including nsy-4, and vab-9, while highly divergent at a sequence level from each other and from the vertebrate claudins, in many cases play roles similar to those traditionally assigned to their vertebrate homologs. These include regulating cell adhesion and passage of small molecules through the paracellular space, channel activity, protein aggregation, sensitivity to pore-forming toxins, intercellular signaling, cell fate specification and dynamic changes in cell morphology. Study of claudin superfamily proteins in C. elegans should continue to provide clues as to how claudin family protein function has been adapted to perform diverse functions at specialized cell-cell contacts in metazoans.
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Requirement for Dlgh-1 in planar cell polarity and skeletogenesis during vertebrate development. PLoS One 2013; 8:e54410. [PMID: 23349879 PMCID: PMC3551758 DOI: 10.1371/journal.pone.0054410] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2012] [Accepted: 12/13/2012] [Indexed: 01/20/2023] Open
Abstract
The development of specialized organs is tightly linked to the regulation of cell growth, orientation, migration and adhesion during embryogenesis. In addition, the directed movements of cells and their orientation within the plane of a tissue, termed planar cell polarity (PCP), appear to be crucial for the proper formation of the body plan. In Drosophila embryogenesis, Discs large (dlg) plays a critical role in apical-basal cell polarity, cell adhesion and cell proliferation. Craniofacial defects in mice carrying an insertional mutation in Dlgh-1 suggest that Dlgh-1 is required for vertebrate development. To determine what roles Dlgh-1 plays in vertebrate development, we generated mice carrying a null mutation in Dlgh-1. We found that deletion of Dlgh-1 caused open eyelids, open neural tube, and misorientation of cochlear hair cell stereociliary bundles, indicative of defects in planar cell polarity (PCP). Deletion of Dlgh-1 also caused skeletal defects throughout the embryo. These findings identify novel roles for Dlgh-1 in vertebrates that differ from its well-characterized roles in invertebrates and suggest that the Dlgh-1 null mouse may be a useful animal model to study certain human congenital birth defects.
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Roberts S, Delury C, Marsh E. The PDZ protein discs-large (DLG): the 'Jekyll and Hyde' of the epithelial polarity proteins. FEBS J 2012; 279:3549-3558. [PMID: 22846345 DOI: 10.1111/j.1742-4658.2012.08729.x] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2012] [Revised: 07/16/2012] [Accepted: 07/26/2012] [Indexed: 12/25/2022]
Abstract
Discs-large (DLG) is a multi-PDZ domain-containing protein that belongs to the family of molecular scaffolding proteins known as membrane guanylate kinases or MAGUKs. DLG is a component of the Scribble polarity complex and genetic analyses of DLG in Drosophila have identified a role for the protein in several key biological processes including the regulation of apico-basal polarity of epithelial cells, as well as other polarity processes such as asymmetric cell division and cell invasion. Disturbance of DLG function leads to uncontrolled epithelial cell proliferation and neoplastic transformation, thereby defining DLG as a potential tumour suppressor. However, whether mammalian homologues of DLG (DLG1, DLG2, DLG3 and DLG4) also possess tumour suppressor functions is not known. In this minireview, we focus on the biological functions of DLG1 in human epithelial cells and on how the function of this MAGUK relates to its intracellular location. We examine some of the evidence that implies that DLG has both tumour suppressor and, paradoxically, oncogenic functions depending upon the precise cellular context.
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Affiliation(s)
- Sally Roberts
- School of Cancer Sciences, University of Birmingham, UK
| | - Craig Delury
- School of Cancer Sciences, University of Birmingham, UK
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Chisholm AD, Xu S. The Caenorhabditis elegans epidermis as a model skin. II: differentiation and physiological roles. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2012; 1:879-902. [PMID: 23539358 DOI: 10.1002/wdev.77] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The Caenorhabditis elegans epidermis forms one of the principal barrier epithelia of the animal. Differentiation of the epidermis begins in mid embryogenesis and involves apical-basal polarization of the cytoskeletal and secretory systems as well as cellular junction formation. Secretion of the external cuticle layers is one of the major developmental and physiological specializations of the epidermal epithelium. The four post-embryonic larval stages are separated by periodic moults, in which the epidermis generates a new cuticle with stage-specific characteristics. The differentiated epidermis also plays key roles in endocrine signaling, fat storage, and ionic homeostasis. The epidermis is intimately associated with the development and function of the nervous system, and may have glial-like roles in modulating neuronal function. The epidermis provides passive and active defenses against skin-penetrating pathogens and can repair small wounds. Finally, age-dependent deterioration of the epidermis is a prominent feature of aging and may affect organismal aging and lifespan.
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Affiliation(s)
- Andrew D Chisholm
- Division of Biological Sciences, Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA, USA.
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Carberry K, Wiesenfahrt T, Geisler F, Stöcker S, Gerhardus H, Überbach D, Davis W, Jorgensen E, Leube RE, Bossinger O. The novel intestinal filament organizer IFO-1 contributes to epithelial integrity in concert with ERM-1 and DLG-1. Development 2012; 139:1851-62. [PMID: 22510987 DOI: 10.1242/dev.075788] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The nematode Caenorhabditis elegans is an excellent model system in which to study in vivo organization and function of the intermediate filament (IF) system for epithelial development and function. Using a transgenic ifb-2::cfp reporter strain, a mutagenesis screen was performed to identify mutants with aberrant expression patterns of the IF protein IFB-2, which is expressed in a dense network at the subapical endotube just below the microvillar brush border of intestinal cells. Two of the isolated alleles (kc2 and kc3) were mapped to the same gene, which we refer to as ifo-1 (intestinal filament organizer). The encoded polypeptide colocalizes with IF proteins and F-actin in the intestine. The apical localization of IFO-1 does not rely on IFB-2 but is dependent on LET-413, a basolateral protein involved in apical junction assembly and maintenance of cell polarity. In mutant worms, IFB-2 and IFC-2 are mislocalized in cytoplasmic granules and accumulate in large aggregates at the C. elegans apical junction (CeAJ) in a DLG-1-dependent fashion. Electron microscopy reveals loss of the prominent endotube and disordered but still intact microvilli. Semiquantitative fluorescence microscopy revealed a significant decrease of F-actin, suggesting a general role of IFO-1 in cytoskeletal organization. Furthermore, downregulation of the cytoskeletal organizer ERM-1 and the adherens junction component DLG-1, each of which leads to F-actin reduction on its own, induces a novel synthetic phenotype in ifo-1 mutants resulting in disruption of the lumen. We conclude that IFO-1 is a multipurpose linker between different cytoskeletal components of the C. elegans intestinal terminal web and contributes to proper epithelial tube formation.
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Affiliation(s)
- Katrin Carberry
- Institute of Molecular and Cellular Anatomy (MOCA), RWTH Aachen University, D-52074 Aachen, Germany
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Zheng S, Gray EE, Chawla G, Porse BT, O'Dell TJ, Black DL. PSD-95 is post-transcriptionally repressed during early neural development by PTBP1 and PTBP2. Nat Neurosci 2012; 15:381-8, S1. [PMID: 22246437 PMCID: PMC3288398 DOI: 10.1038/nn.3026] [Citation(s) in RCA: 165] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2011] [Accepted: 12/14/2011] [Indexed: 11/09/2022]
Abstract
Postsynaptic density protein 95 (PSD-95) is essential for synaptic maturation and plasticity. Although its synaptic regulation has been widely studied, the control of PSD-95 cellular expression is not understood. We found that Psd-95 was controlled post-transcriptionally during neural development. Psd-95 was transcribed early in mouse embryonic brain, but most of its product transcripts were degraded. The polypyrimidine tract binding proteins PTBP1 and PTBP2 repressed Psd-95 (also known as Dlg4) exon 18 splicing, leading to premature translation termination and nonsense-mediated mRNA decay. The loss of first PTBP1 and then of PTBP2 during embryonic development allowed splicing of exon 18 and expression of PSD-95 late in neuronal maturation. Re-expression of PTBP1 or PTBP2 in differentiated neurons inhibited PSD-95 expression and impaired the development of glutamatergic synapses. Thus, expression of PSD-95 during early neural development is controlled at the RNA level by two PTB proteins whose sequential downregulation is necessary for synapse maturation.
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Affiliation(s)
- Sika Zheng
- Howard Hughes Medical Institute, University of California at Los Angeles, Los Angeles, California, USA
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Abstract
Caenorhabditis elegans provides a simplified, in vivo model system in which to study adherens junctions (AJs) and their role in morphogenesis. The core AJ components-HMR-1/E-cadherin, HMP-2/β-catenin and HMP-1/α-catenin-were initially identified through genetic screens for mutants with body axis elongation defects. In early embryos, AJ proteins are found at sites of contact between blastomeres, and in epithelial cells AJ proteins localize to the multifaceted apical junction (CeAJ)-a single structure that combines the adhesive and barrier functions of vertebrate adherens and tight junctions. The apically localized polarity proteins PAR-3 and PAR-6 mediate formation and maturation of junctions, while the basolaterally localized regulator LET-413/Scribble ensures that junctions remain apically positioned. AJs promote robust adhesion between epithelial cells and provide mechanical resistance for the physical strains of morphogenesis. However, in contrast to vertebrates, C. elegans AJ proteins are not essential for general cell adhesion or for epithelial cell polarization. A combination of conserved and novel proteins localizes to the CeAJ and works together with AJ proteins to mediate adhesion.
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Viveiros R, Hutter H, Moerman DG. Membrane extensions are associated with proper anterior migration of muscle cells during Caenorhabditis elegans embryogenesis. Dev Biol 2011; 358:189-200. [PMID: 21820426 DOI: 10.1016/j.ydbio.2011.07.026] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2011] [Accepted: 07/17/2011] [Indexed: 01/01/2023]
Abstract
C. elegans body wall muscle is formed after a series of well-orchestrated steps. With the onset of specification embryonic muscle cells accumulate under the hypodermal seam cells at the left and right sides of the embryo. Shortly thereafter they begin to migrate dorsally and ventrally resting beneath the dorsal and ventral hypodermis eventually forming the four muscle quadrants present upon hatching. In this study we describe the plasma membrane dynamics of these migrating cells and observe the extension of filopodia and lamellipodia during dorso-ventral migration but not during the earlier stages of accumulation. We also describe an anterior migration event during embryonic muscle morphogenesis, whereby the anterior-most pair of cells in each of the four muscle quadrants extends long processes to the anterior tip of the developing embryo. Anteriormost muscle cells then follow these extensions into their final positions in the developing embryo. Using RNAi and mutant analysis, we have identified laminin as being involved in mediating the dorsal-ventral muscle migrations. Finally we show that the α-integrin INA-1, the ephrin VAB-2 and its receptor VAB-1 and the Robo receptor SAX-3 indirectly promote the proper extension of the ventral anterior muscle processes by organizing the embryonic neurons so as to provide a clear path for muscle membrane extension.
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Affiliation(s)
- Ryan Viveiros
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada
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Bernadskaya YY, Patel FB, Hsu HT, Soto MC. Arp2/3 promotes junction formation and maintenance in the Caenorhabditis elegans intestine by regulating membrane association of apical proteins. Mol Biol Cell 2011; 22:2886-99. [PMID: 21697505 PMCID: PMC3154884 DOI: 10.1091/mbc.e10-10-0862] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
It has been proposed that Arp2/3, which promotes nucleation of branched actin, is needed for epithelial junction initiation but is less important as junctions mature. We focus here on how Arp2/3 contributes to the Caenorhabditis elegans intestinal epithelium and find important roles for Arp2/3 in the maturation and maintenance of junctions in embryos and adults. Electron microscope studies show that embryos depleted of Arp2/3 form apical actin-rich microvilli and electron-dense apical junctions. However, whereas apical/basal polarity initiates, apical maturation is defective, including decreased apical F-actin enrichment, aberrant lumen morphology, and reduced accumulation of some apical junctional proteins, including DLG-1. Depletion of Arp2/3 in adult animals leads to similar intestinal defects. The DLG-1/AJM-1 apical junction proteins, and the ezrin-radixin-moesin homologue ERM-1, a protein that connects F-actin to membranes, are required along with Arp2/3 for apical F-actin enrichment in embryos, whereas cadherin junction proteins are not. Arp2/3 affects the subcellular distribution of DLG-1 and ERM-1. Loss of Arp2/3 shifts both ERM-1 and DLG-1 from pellet fractions to supernatant fractions, suggesting a role for Arp2/3 in the distribution of membrane-associated proteins. Thus, Arp2/3 is required as junctions mature to maintain apical proteins associated with the correct membranes.
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Affiliation(s)
- Yelena Y Bernadskaya
- Department of Pathology and Laboratory Medicine, University of Medicine and Dentistry of New Jersey-Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA
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Abstract
In the last decade, the claudin family of integral membrane proteins has been identified as the major protein component of the tight junctions in all vertebrates. The claudin superfamily proteins also function to regulate channel activity, intercellular signaling, and cell morphology. Subsequently, claudin homologues have been identified in invertebrates, including Drosophila and Caenorhabditis elegans. Recent studies demonstrate that the C. elegans claudins, clc-1 to clc-5, and similar proteins in the greater PMP22/EMP/claudin/calcium channel γ subunit family, including nsy-1-nsy-4 and vab-9, while highly divergent at a sequence level from each other and from the vertebrate claudins, in some cases play roles similar to those traditionally assigned to their vertebrate homologues. These include regulating cell adhesion and passage of small molecules through the paracellular space. The claudin superfamily proteins also function to regulate channel activity, intercellular signaling, and cell morphology. Study of claudin superfamily proteins in C. elegans should continue to provide clues as to how core claudin protein function can be modified to serve various specific roles at regions of cell-cell contact in metazoans.
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Kramer LB, Shim J, Previtera ML, Isack NR, Lee MC, Firestein BL, Rongo C. UEV-1 is an ubiquitin-conjugating enzyme variant that regulates glutamate receptor trafficking in C. elegans neurons. PLoS One 2010; 5:e14291. [PMID: 21179194 PMCID: PMC3001443 DOI: 10.1371/journal.pone.0014291] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2010] [Accepted: 11/18/2010] [Indexed: 11/18/2022] Open
Abstract
The regulation of AMPA-type glutamate receptor (AMPAR) membrane trafficking is a key mechanism by which neurons regulate synaptic strength and plasticity. AMPAR trafficking is modulated through a combination of receptor phosphorylation, ubiquitination, endocytosis, and recycling, yet the factors that mediate these processes are just beginning to be uncovered. Here we identify the ubiquitin-conjugating enzyme variant UEV-1 as a regulator of AMPAR trafficking in vivo. We identified mutations in uev-1 in a genetic screen for mutants with altered trafficking of the AMPAR subunit GLR-1 in C. elegans interneurons. Loss of uev-1 activity results in the accumulation of GLR-1 in elongated accretions in neuron cell bodies and along the ventral cord neurites. Mutants also have a corresponding behavioral defect--a decrease in spontaneous reversals in locomotion--consistent with diminished GLR-1 function. The localization of other synaptic proteins in uev-1-mutant interneurons appears normal, indicating that the GLR-1 trafficking defects are not due to gross deficiencies in synapse formation or overall protein trafficking. We provide evidence that GLR-1 accumulates at RAB-10-containing endosomes in uev-1 mutants, and that receptors arrive at these endosomes independent of clathrin-mediated endocytosis. UEV-1 homologs in other species bind to the ubiquitin-conjugating enzyme Ubc13 to create K63-linked polyubiquitin chains on substrate proteins. We find that whereas UEV-1 can interact with C. elegans UBC-13, global levels of K63-linked ubiquitination throughout nematodes appear to be unaffected in uev-1 mutants, even though UEV-1 is broadly expressed in most tissues. Nevertheless, ubc-13 mutants are similar in phenotype to uev-1 mutants, suggesting that the two proteins do work together to regulate GLR-1 trafficking. Our results suggest that UEV-1 could regulate a small subset of K63-linked ubiquitination events in nematodes, at least one of which is critical in regulating GLR-1 trafficking.
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Affiliation(s)
- Lawrence B Kramer
- The Waksman Institute, Department of Genetics, Rutgers, The State University of New Jersey, Piscataway, New Jersey, United States of America
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Chen L, Zhou S. "CRASH"ing with the worm: insights into L1CAM functions and mechanisms. Dev Dyn 2010; 239:1490-501. [PMID: 20225255 DOI: 10.1002/dvdy.22269] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The L1 family of cell adhesion molecules (L1CAMs) in vertebrates has long been studied for its roles in nervous system development and function. Members of this family have been associated with distinct neurological disorders that include CRASH, autism, 3p syndrome, and schizophrenia. The conservation of L1CAMs in Drosophila and Caenorhabditis elegans allows the opportunity to take advantage of these simple model organisms and their accessible genetic manipulations to dissect L1CAM functions and mechanisms of action. This review summarizes the discoveries of L1CAMs made in C. elegans, showcasing this simple model organism as a powerful system to uncover L1CAM mechanisms and roles in healthy and diseased states.
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Affiliation(s)
- Lihsia Chen
- Department of Genetics, Cell Biology, and Development, Developmental Biology Center, University of Minnesota, Minneapolis, Minnesota 55455, USA.
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Conserved mechanism of Wnt signaling function in the specification of vulval precursor fates in C. elegans and C. briggsae. Dev Biol 2010; 346:128-39. [PMID: 20624381 DOI: 10.1016/j.ydbio.2010.07.003] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2010] [Revised: 06/17/2010] [Accepted: 07/01/2010] [Indexed: 01/29/2023]
Abstract
The C. elegans hermaphrodite vulva serves as a paradigm for understanding how signaling pathways control organ formation. Previous studies have shown that Wnt signaling plays important roles in vulval development. To understand the function and evolution of Wnt signaling in Caenorhabditis nematodes we focused on C. briggsae, a species that is substantially divergent from C. elegans in terms of the evolutionary time scale yet shares almost identical morphology. We isolated mutants in C. briggsae that display multiple pseudo-vulvae resulting from ectopic VPC induction. We cloned one of these loci and found that it encodes an Axin homolog, Cbr-PRY-1. Our genetic studies revealed that Cbr-pry-1 functions upstream of the canonical Wnt pathway components Cbr-bar-1 (beta-catenin) and Cbr-pop-1(tcf/lef) as well as the Hox target Cbr-lin-39 (Dfd/Scr). We further characterized the pry-1 vulval phenotype in C. briggsae and C. elegans using 8 cell fate markers, cell ablation, and genetic interaction approaches. Our results show that ectopically induced VPCs in pry-1 mutants adopt 2° fates independently of the gonad-derived inductive and LIN-12/Notch-mediated lateral signaling pathways. We also found that Cbr-pry-1 mutants frequently show a failure of P7.p induction. A similar, albeit low penetrant, defect is also observed in C. elegans pry-1 mutants. The genetic analysis of the P7.p induction defect revealed that it was caused by altered regulation of lin-12 and its transcriptional target lip-1 (MAP kinase phosphatase). Thus, our results provide evidence for LIN-12/Notch-dependent and independent roles of Wnt signaling in promoting 2 degrees VPC fates in both nematode species.
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Achilleos A, Wehman AM, Nance J. PAR-3 mediates the initial clustering and apical localization of junction and polarity proteins during C. elegans intestinal epithelial cell polarization. Development 2010; 137:1833-42. [PMID: 20431121 DOI: 10.1242/dev.047647] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The apicobasal polarity of epithelial cells is critical for organ morphogenesis and function, and loss of polarity can promote tumorigenesis. Most epithelial cells form when precursor cells receive a polarization cue, develop distinct apical and basolateral domains and assemble junctions near their apical surface. The scaffolding protein PAR-3 regulates epithelial cell polarity, but its cellular role in the transition from precursor cell to polarized epithelial cell has not been determined in vivo. Here, we use a targeted protein-degradation strategy to remove PAR-3 from C. elegans embryos and examine its cellular role as intestinal precursor cells become polarized epithelial cells. At initial stages of polarization, PAR-3 accumulates in cortical foci that contain E-cadherin, other adherens junction proteins, and the polarity proteins PAR-6 and PKC-3. Using live imaging, we show that PAR-3 foci move apically and cluster, and that PAR-3 is required to assemble E-cadherin into foci and for foci to accumulate at the apical surface. We propose that PAR-3 facilitates polarization by promoting the initial clustering of junction and polarity proteins that then travel and accumulate apically. Unexpectedly, superficial epidermal cells form apical junctions in the absence of PAR-3, and we show that PAR-6 has a PAR-3-independent role in these cells to promote apical junction maturation. These findings indicate that PAR-3 and PAR-6 function sequentially to position and mature apical junctions, and that the requirement for PAR-3 can vary in different types of epithelial cells.
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Affiliation(s)
- Annita Achilleos
- Helen L. and Martin S. Kimmel Center for Biology and Medicine at the Skirball Institute for Biomolecular Medicine, NYU School of Medicine, New York, NY 10016, USA
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Hadwiger G, Dour S, Arur S, Fox P, Nonet ML. A monoclonal antibody toolkit for C. elegans. PLoS One 2010; 5:e10161. [PMID: 20405020 PMCID: PMC2854156 DOI: 10.1371/journal.pone.0010161] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2010] [Accepted: 03/22/2010] [Indexed: 01/12/2023] Open
Abstract
Background Antibodies are critical tools in many avenues of biological research. Though antibodies can be produced in the research laboratory setting, most research labs working with vertebrates avail themselves of the wide array of commercially available reagents. By contrast, few such reagents are available for work with model organisms. Methodology/Principal Findings We report the production of monoclonal antibodies directed against a wide range of proteins that label specific subcellular and cellular components, and macromolecular complexes. Antibodies were made to synaptobrevin (SNB-1), a component of synaptic vesicles; to Rim (UNC-10), a protein localized to synaptic active zones; to transforming acidic coiled-coil protein (TAC-1), a component of centrosomes; to CENP-C (HCP-4), which in worms labels the entire length of their holocentric chromosomes; to ORC2 (ORC-2), a subunit of the DNA origin replication complex; to the nucleolar phosphoprotein NOPP140 (DAO-5); to the nuclear envelope protein lamin (LMN-1); to EHD1 (RME-1) a marker for recycling endosomes; to caveolin (CAV-1), a marker for caveolae; to the cytochrome P450 (CYP-33E1), a resident of the endoplasmic reticulum; to β-1,3-glucuronyltransferase (SQV-8) that labels the Golgi; to a chaperonin (HSP-60) targeted to mitochondria; to LAMP (LMP-1), a resident protein of lysosomes; to the alpha subunit of the 20S subcomplex (PAS-7) of the 26S proteasome; to dynamin (DYN-1) and to the α-subunit of the adaptor complex 2 (APA-2) as markers for sites of clathrin-mediated endocytosis; to the MAGUK, protein disks large (DLG-1) and cadherin (HMR-1), both of which label adherens junctions; to a cytoskeletal linker of the ezrin-radixin-moesin family (ERM-1), which localized to apical membranes; to an ERBIN family protein (LET-413) which localizes to the basolateral membrane of epithelial cells and to an adhesion molecule (SAX-7) which localizes to the plasma membrane at cell-cell contacts. In addition to working in whole mount immunocytochemistry, most of these antibodies work on western blots and thus should be of use for biochemical fractionation studies. Conclusions/Significance We have produced a set of monoclonal antibodies to subcellular components of the nematode C. elegans for the research community. These reagents are being made available through the Developmental Studies Hybridoma Bank (DSHB).
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Affiliation(s)
- Gayla Hadwiger
- Department of Anatomy and Neurobiology, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Scott Dour
- Department of Anatomy and Neurobiology, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Swathi Arur
- Department of Genetics, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Paul Fox
- Department of Genetics, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Michael L. Nonet
- Department of Anatomy and Neurobiology, Washington University School of Medicine, St. Louis, Missouri, United States of America
- * E-mail:
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Pellegrino MW, Gasser RB, Sprenger F, Stetak A, Hajnal A. The conserved zinc finger protein VAB-23 is an essential regulator of epidermal morphogenesis in Caenorhabditis elegans. Dev Biol 2009; 336:84-93. [DOI: 10.1016/j.ydbio.2009.09.036] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2009] [Revised: 09/17/2009] [Accepted: 09/23/2009] [Indexed: 01/29/2023]
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Rivera C, Yamben IF, Shatadal S, Waldof M, Robinson ML, Griep AE. Cell-autonomous requirements for Dlg-1 for lens epithelial cell structure and fiber cell morphogenesis. Dev Dyn 2009; 238:2292-308. [PMID: 19623611 DOI: 10.1002/dvdy.22036] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Cell polarity and adhesion are thought to be key determinants in organismal development. In Drosophila, discs large (dlg) has emerged as an important regulator of epithelial cell proliferation, adhesion, and polarity. Herein, we investigated the role of the mouse homolog of dlg (Dlg-1) in the development of the mouse ocular lens. Tissue-specific ablation of Dlg-1 throughout the lens early in lens development led to an expansion and disorganization of the epithelium that correlated with changes in the distribution of adhesion and polarity factors. In the fiber cells, differentiation defects were observed. These included alterations in cell structure and the disposition of cell adhesion/cytoskeletal factors, delay in denucleation, and reduced levels of alpha-catenin, pERK1/2, and MIP26. These fiber cell defects were recapitulated when Dlg-1 was disrupted only in fiber cells. These results suggest that Dlg-1 acts in a cell autonomous manner to regulate epithelial cell structure and fiber cell differentiation.
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Affiliation(s)
- Charlene Rivera
- Department of Anatomy, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin 53706, USA
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Emtage L, Chang H, Tiver R, Rongo C. MAGI-1 modulates AMPA receptor synaptic localization and behavioral plasticity in response to prior experience. PLoS One 2009; 4:e4613. [PMID: 19242552 PMCID: PMC2645691 DOI: 10.1371/journal.pone.0004613] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2008] [Accepted: 01/19/2009] [Indexed: 12/04/2022] Open
Abstract
It is well established that the efficacy of synaptic connections can be rapidly modified by neural activity, yet how the environment and prior experience modulate such synaptic and behavioral plasticity is only beginning to be understood. Here we show in C. elegans that the broadly conserved scaffolding molecule MAGI-1 is required for the plasticity observed in a glutamatergic circuit. This mechanosensory circuit mediates reversals in locomotion in response to touch stimulation, and the AMPA-type receptor (AMPAR) subunits GLR-1 and GLR-2, which are required for reversal behavior, are localized to ventral cord synapses in this circuit. We find that animals modulate GLR-1 and GLR-2 localization in response to prior mechanosensory stimulation; a specific isoform of MAGI-1 (MAGI-1L) is critical for this modulation. We show that MAGI-1L interacts with AMPARs through the intracellular domain of the GLR-2 subunit, which is required for the modulation of AMPAR synaptic localization by mechanical stimulation. In addition, mutations that prevent the ubiquitination of GLR-1 prevent the decrease in AMPAR localization observed in previously stimulated magi-1 mutants. Finally, we find that previously-stimulated animals later habituate to subsequent mechanostimulation more rapidly compared to animals initially reared without mechanical stimulation; MAGI-1L, GLR-1, and GLR-2 are required for this change in habituation kinetics. Our findings demonstrate that prior experience can cause long-term alterations in both behavioral plasticity and AMPAR localization at synapses in an intact animal, and indicate a new, direct role for MAGI/S-SCAM proteins in modulating AMPAR localization and function in the wake of variable sensory experience.
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Affiliation(s)
- Lesley Emtage
- The Waksman Institute, Department of Genetics, Rutgers University, Piscataway, New Jersey, United States of America
| | - Howard Chang
- The Waksman Institute, Department of Genetics, Rutgers University, Piscataway, New Jersey, United States of America
| | - Rebecca Tiver
- The Waksman Institute, Department of Genetics, Rutgers University, Piscataway, New Jersey, United States of America
| | - Christopher Rongo
- The Waksman Institute, Department of Genetics, Rutgers University, Piscataway, New Jersey, United States of America
- * E-mail:
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