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Pinot M, Le Borgne R. Spatio-Temporal Regulation of Notch Activation in Asymmetrically Dividing Sensory Organ Precursor Cells in Drosophila melanogaster Epithelium. Cells 2024; 13:1133. [PMID: 38994985 PMCID: PMC11240559 DOI: 10.3390/cells13131133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2024] [Revised: 06/24/2024] [Accepted: 06/25/2024] [Indexed: 07/13/2024] Open
Abstract
The Notch communication pathway, discovered in Drosophila over 100 years ago, regulates a wide range of intra-lineage decisions in metazoans. The division of the Drosophila mechanosensory organ precursor is the archetype of asymmetric cell division in which differential Notch activation takes place at cytokinesis. Here, we review the molecular mechanisms by which epithelial cell polarity, cell cycle and intracellular trafficking participate in controlling the directionality, subcellular localization and temporality of mechanosensitive Notch receptor activation in cytokinesis.
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Affiliation(s)
| | - Roland Le Borgne
- Univ Rennes, Centre National de la Recherche Scientifique UMR 6290, IGDR (Institut de Génétique et Développement de Rennes), F-35000 Rennes, France
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2
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Zobel M, Disanza A, Senic-Matuglia F, Franco M, Colaluca IN, Confalonieri S, Bisi S, Barbieri E, Caldieri G, Sigismund S, Pece S, Chavrier P, Di Fiore PP, Scita G. A NUMB-EFA6B-ARF6 recycling route controls apically restricted cell protrusions and mesenchymal motility. J Cell Biol 2018; 217:3161-3182. [PMID: 30061108 PMCID: PMC6123001 DOI: 10.1083/jcb.201802023] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Revised: 05/17/2018] [Accepted: 06/05/2018] [Indexed: 12/13/2022] Open
Abstract
The endocytic protein NUMB has been implicated in the control of various polarized cellular processes, including the acquisition of mesenchymal migratory traits through molecular mechanisms that have only been partially defined. Here, we report that NUMB is a negative regulator of a specialized set of understudied, apically restricted, actin-based protrusions, the circular dorsal ruffles (CDRs), induced by either PDGF or HGF stimulation. Through its PTB domain, NUMB binds directly to an N-terminal NPLF motif of the ARF6 guanine nucleotide exchange factor, EFA6B, and promotes its exchange activity in vitro. In cells, a NUMB-EFA6B-ARF6 axis regulates the recycling of the actin regulatory cargo RAC1 and is critical for the formation of CDRs that mark the acquisition of a mesenchymal mode of motility. Consistently, loss of NUMB promotes HGF-induced cell migration and invasion. Thus, NUMB negatively controls membrane protrusions and the acquisition of mesenchymal migratory traits by modulating EFA6B-ARF6 activity.
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Affiliation(s)
- Martina Zobel
- IFOM, the FIRC Institute of Molecular Oncology, Milan, Italy
| | - Andrea Disanza
- IFOM, the FIRC Institute of Molecular Oncology, Milan, Italy
| | | | - Michel Franco
- Université Côte d'Azur, Centre National de la Recherche Scientifique, Institut de Pharmacologie Moléculaire et Cellulaire, Valbonne, France
| | | | | | - Sara Bisi
- IFOM, the FIRC Institute of Molecular Oncology, Milan, Italy
| | - Elisa Barbieri
- Department of Experimental Oncology, European Institute of Oncology, Milan, Italy
| | - Giusi Caldieri
- Department of Experimental Oncology, European Institute of Oncology, Milan, Italy
- Department of Oncology and Hemato-Oncology, University of Milan, Milan, Italy
| | - Sara Sigismund
- Department of Experimental Oncology, European Institute of Oncology, Milan, Italy
- Department of Oncology and Hemato-Oncology, University of Milan, Milan, Italy
| | - Salvatore Pece
- Department of Experimental Oncology, European Institute of Oncology, Milan, Italy
- Department of Oncology and Hemato-Oncology, University of Milan, Milan, Italy
| | - Philippe Chavrier
- Institut Curie, PSL Research University, Paris, France
- Centre National de la Recherche Scientifique UMR 144, Membrane and Cytoskeleton Dynamics Team, Paris, France
| | - Pier Paolo Di Fiore
- IFOM, the FIRC Institute of Molecular Oncology, Milan, Italy
- Department of Experimental Oncology, European Institute of Oncology, Milan, Italy
- Department of Oncology and Hemato-Oncology, University of Milan, Milan, Italy
| | - Giorgio Scita
- IFOM, the FIRC Institute of Molecular Oncology, Milan, Italy
- Department of Oncology and Hemato-Oncology, University of Milan, Milan, Italy
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3
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Johnson SA, Zitserman D, Roegiers F. Numb regulates the balance between Notch recycling and late-endosome targeting in Drosophila neural progenitor cells. Mol Biol Cell 2016; 27:2857-66. [PMID: 27466320 PMCID: PMC5025272 DOI: 10.1091/mbc.e15-11-0751] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Accepted: 07/21/2016] [Indexed: 11/11/2022] Open
Abstract
Steady-state and pulse-labeling techniques are used to follow Notch receptors in sensory organ precursor cells in Drosophila. Numb and L(2)gl antagonize a pool of Notch receptors, and Numb promotes Notch targeting to late endosomes in Drosophila neural progenitors to regulate Notch signaling and cell fate. The Notch signaling pathway plays essential roles in both animal development and human disease. Regulation of Notch receptor levels in membrane compartments has been shown to affect signaling in a variety of contexts. Here we used steady-state and pulse-labeling techniques to follow Notch receptors in sensory organ precursor cells in Drosophila. We find that the endosomal adaptor protein Numb regulates levels of Notch receptor trafficking to Rab7-labeled late endosomes but not early endosomes. Using an assay we developed that labels different pools of Notch receptors as they move through the endocytic system, we show that Numb specifically suppresses a recycled Notch receptor subpopulation and that excess Notch signaling in numb mutants requires the recycling endosome GTPase Rab11 activity. Our data therefore suggest that Numb controls the balance between Notch receptor recycling and receptor targeting to late endosomes to regulate signaling output after asymmetric cell division in Drosophila neural progenitors.
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Affiliation(s)
- Seth A Johnson
- Fox Chase Cancer Center, Philadelphia, PA 19111 Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Diana Zitserman
- Fox Chase Cancer Center, Philadelphia, PA 19111 University of Bridgeport, Bridgeport, CT 06604
| | - Fabrice Roegiers
- Fox Chase Cancer Center, Philadelphia, PA 19111 Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
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Regulation of Notch Signaling Through Intracellular Transport. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2016; 323:107-27. [PMID: 26944620 DOI: 10.1016/bs.ircmb.2015.12.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The highly conserved Notch-signaling pathway performs a central role in cell differentiation, survival, and proliferation. A major mechanism by which cells modulate signaling is by controlling the intracellular transport itinerary of Notch. Indeed, Notch removal from the cell surface and its targeting to the lysosome for degradation is one way in which Notch activity is downregulated since it limits receptor exposure to ligand. In contrast, Notch-signaling capacity is maintained through repeated rounds of receptor recycling and redelivery of Notch to the cell surface from endosomal stores. This review discusses the molecular mechanisms by which Notch transit through the endosome is controlled and how various intracellular sorting decisions are thought to impact signaling activity.
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Leung A, Hua K, Ramachandran P, Hingwing K, Wu M, Koh PL, Hawkins N. C. elegans HAM-1 functions in the nucleus to regulate asymmetric neuroblast division. Dev Biol 2015; 410:56-69. [PMID: 26703426 DOI: 10.1016/j.ydbio.2015.12.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Revised: 12/08/2015] [Accepted: 12/10/2015] [Indexed: 01/19/2023]
Abstract
All 302 neurons in the C. elegans hermaphrodite arise through asymmetric division of neuroblasts. During embryogenesis, the C. elegans ham-1 gene is required for several asymmetric neuroblast divisions in lineages that generate both neural and apoptotic cells. By antibody staining, endogenous HAM-1 is found exclusively at the cell cortex in many cells during embryogenesis and is asymmetrically localized in dividing cells. Here we show that in transgenic embryos expressing a functional GFP::HAM-1 fusion protein, GFP expression is also detected in the nucleus, in addition to the cell cortex. Consistent with the nuclear localization is the presence of a putative DNA binding winged-helix domain within the N-terminus of HAM-1. Through a deletion analysis we determined that the C-terminus of the protein is required for nuclear localization and we identified two nuclear localization sequences (NLSs). A subcellular fractionation experiment from wild type embryos, followed by Western blotting, revealed that endogenous HAM-1 is primarily found in the nucleus. Our analysis also showed that the N-terminus is necessary for cortical localization. While ham-1 function is essential for asymmetric division in the lineage that generates the PLM mechanosensory neuron, we showed that cortical localization may not required. Thus, our results suggest that there is a nuclear function for HAM-1 in regulating asymmetric neuroblast division and that the requirement for cortical localization may be lineage dependent.
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Affiliation(s)
- Amy Leung
- Department of Molecular Biology and Biochemistry Simon Fraser University, Burnaby, BC, Canada
| | - Khang Hua
- Department of Molecular Biology and Biochemistry Simon Fraser University, Burnaby, BC, Canada
| | | | - Kyla Hingwing
- Department of Molecular Biology and Biochemistry Simon Fraser University, Burnaby, BC, Canada
| | - Maria Wu
- Department of Molecular Biology and Biochemistry Simon Fraser University, Burnaby, BC, Canada
| | - Pei Luan Koh
- Department of Molecular Biology and Biochemistry Simon Fraser University, Burnaby, BC, Canada
| | - Nancy Hawkins
- Department of Molecular Biology and Biochemistry Simon Fraser University, Burnaby, BC, Canada.
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6
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Schweisguth F. Asymmetric cell division in the Drosophila bristle lineage: from the polarization of sensory organ precursor cells to Notch-mediated binary fate decision. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2015; 4:299-309. [PMID: 25619594 PMCID: PMC4671255 DOI: 10.1002/wdev.175] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/24/2014] [Revised: 12/11/2014] [Accepted: 12/19/2014] [Indexed: 12/26/2022]
Abstract
Asymmetric cell division (ACD) is a simple and evolutionary conserved process whereby a mother divides to generate two daughter cells with distinct developmental potentials. This process can generate cell fate diversity during development. Fate asymmetry may result from the unequal segregation of molecules and/or organelles between the two daughter cells. Here, I will review how fate asymmetry is regulated in the sensory bristle lineage in Drosophila and focus on the molecular mechanisms underlying ACD of the sensory organ precursor cells (SOPs). WIREs Dev Biol 2015, 4:299–309. doi: 10.1002/wdev.175 For further resources related to this article, please visit theWIREs website. Conflict of interest: The author has declared no conflicts of interest for this article.
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7
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Couturier L, Trylinski M, Mazouni K, Darnet L, Schweisguth F. A fluorescent tagging approach in Drosophila reveals late endosomal trafficking of Notch and Sanpodo. ACTA ACUST UNITED AC 2014; 207:351-63. [PMID: 25365996 PMCID: PMC4226730 DOI: 10.1083/jcb.201407071] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Signaling and endocytosis are highly integrated processes that regulate cell fate. In the Drosophila melanogaster sensory bristle lineages, Numb inhibits the recycling of Notch and its trafficking partner Sanpodo (Spdo) to regulate cell fate after asymmetric cell division. In this paper, we have used a dual GFP/Cherry tagging approach to study the distribution and endosomal sorting of Notch and Spdo in living pupae. The specific properties of GFP, i.e., quenching at low pH, and Cherry, i.e., slow maturation time, revealed distinct pools of Notch and Spdo: cargoes exhibiting high GFP/low Cherry fluorescence intensities localized mostly at the plasma membrane and early/sorting endosomes, whereas low GFP/high Cherry cargoes accumulated in late acidic endosomes. These properties were used to show that Spdo is sorted toward late endosomes in a Numb-dependent manner. This dual-tagging approach should be generally applicable to study the trafficking dynamics of membrane proteins in living cells and tissues.
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Affiliation(s)
- Lydie Couturier
- Developmental and Stem Cell Biology Department, Institut Pasteur, 75015 Paris, France Centre National de la Recherche Scientifique, URA2578, 75015 Paris, France
| | - Mateusz Trylinski
- Developmental and Stem Cell Biology Department, Institut Pasteur, 75015 Paris, France Centre National de la Recherche Scientifique, URA2578, 75015 Paris, France Master Biosciences, École Normale Supérieure de Lyon, 75015 Paris, France
| | - Khallil Mazouni
- Developmental and Stem Cell Biology Department, Institut Pasteur, 75015 Paris, France Centre National de la Recherche Scientifique, URA2578, 75015 Paris, France
| | - Léa Darnet
- Developmental and Stem Cell Biology Department, Institut Pasteur, 75015 Paris, France Centre National de la Recherche Scientifique, URA2578, 75015 Paris, France
| | - François Schweisguth
- Developmental and Stem Cell Biology Department, Institut Pasteur, 75015 Paris, France Centre National de la Recherche Scientifique, URA2578, 75015 Paris, France
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8
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Abstract
The counterbalancing action of the endocytosis and secretory pathways maintains a dynamic equilibrium that regulates the composition of the plasma membrane, allowing it to maintain homeostasis and to change rapidly in response to alterations in the extracellular environment and/or intracellular metabolism. These pathways are intimately integrated with intercellular signaling systems and play critical roles in all cells. Studies in Caenorhabditis elegans have revealed diverse roles of membrane trafficking in physiology and development and have also provided molecular insight into the fundamental mechanisms that direct cargo sorting, vesicle budding, and membrane fisson and fusion. In this review, we summarize progress in understanding membrane trafficking mechanisms derived from work in C. elegans, focusing mainly on work done in non-neuronal cell-types, especially the germline, early embryo, coelomocytes, and intestine.
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Affiliation(s)
- Ken Sato
- Laboratory of Molecular Traffic, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi, Gunma 371-8512, Japan. ;
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9
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Leitch CC, Lodh S, Prieto-Echagüe V, Badano JL, Zaghloul NA. Basal body proteins regulate Notch signaling through endosomal trafficking. J Cell Sci 2014; 127:2407-19. [PMID: 24681783 DOI: 10.1242/jcs.130344] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Proteins associated with primary cilia and basal bodies mediate numerous signaling pathways, but little is known about their role in Notch signaling. Here, we report that loss of the Bardet-Biedl syndrome proteins BBS1 or BBS4 produces increased Notch-directed transcription in a zebrafish reporter line and in human cell lines. Pathway overactivation is accompanied by reduced localization of Notch receptor at both the plasma membrane and the cilium. In Drosophila mutants, overactivation of Notch can result from receptor accumulation in endosomes, and recent studies implicate ciliary proteins in endosomal trafficking, suggesting a possible mechanism by which overactivation occurs in BBS mutants. Consistent with this, we observe genetic interaction of BBS1 and BBS4 with the endosomal sorting complexes required for transport (ESCRT) gene TSG101 and accumulation of receptor in late endosomes, reduced endosomal recycling and reduced receptor degradation in lysosomes. We observe similar defects with disruption of BBS3. Loss of another basal body protein, ALMS1, also enhances Notch activation and the accumulation of receptor in late endosomes, but does not disrupt recycling. These findings suggest a role for these proteins in the regulation of Notch through endosomal trafficking of the receptor.
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Affiliation(s)
- Carmen C Leitch
- Department of Medicine, Division of Endocrinology, Diabetes, and Nutrition, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Sukanya Lodh
- Department of Medicine, Division of Endocrinology, Diabetes, and Nutrition, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | | | - Jose L Badano
- Institut Pasteur de Montevideo, CP11400 Montevideo, Uruguay
| | - Norann A Zaghloul
- Department of Medicine, Division of Endocrinology, Diabetes, and Nutrition, University of Maryland School of Medicine, Baltimore, MD 21201, USA
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Abstract
Polarized cells such as epithelial cells and neurons exhibit different plasma membrane domains with distinct protein compositions. Recent studies have shown that sorting of transmembrane proteins to the basolateral domain of epithelial cells and the somatodendritic domain of neurons is mediated by recognition of signals in the cytosolic domains of the proteins by adaptors. These adaptors are components of protein coats associated with the trans-Golgi network and/or recycling endosomes. The clathrin-associated adaptor protein 1 (AP-1) complex plays a preeminent role in this process, although other adaptors and coat proteins, such as AP-4, ARH, Numb, exomer, and retromer, have also been implicated.
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Affiliation(s)
- Juan S Bonifacino
- Cell Biology and Metabolism Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892
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Traub LM, Bonifacino JS. Cargo recognition in clathrin-mediated endocytosis. Cold Spring Harb Perspect Biol 2013; 5:a016790. [PMID: 24186068 DOI: 10.1101/cshperspect.a016790] [Citation(s) in RCA: 214] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The endosomal system is expansive and complex, characterized by swift morphological transitions, dynamic remodeling of membrane constituents, and intracellular positioning changes. To properly navigate this ever-altering membrane labyrinth, transmembrane protein cargoes typically require specific sorting signals that are decoded by components of protein coats. The best-characterized sorting process within the endosomal system is the rapid internalization of select transmembrane proteins within clathrin-coated vesicles. Endocytic signals consist of linear motifs, conformational determinants, or covalent modifications in the cytosolic domains of transmembrane cargo. These signals are interpreted by a diverse set of clathrin-associated sorting proteins (CLASPs) that translocate from the cytosol to the inner face of the plasma membrane. Signal recognition by CLASPs is highly cooperative, involving additional interactions with phospholipids, Arf GTPases, other CLASPs, and clathrin, and is regulated by large conformational changes and covalent modifications. Related sorting events occur at other endosomal sorting stations.
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Affiliation(s)
- Linton M Traub
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261
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Cotton M, Benhra N, Le Borgne R. Numb Inhibits the Recycling of Sanpodo in Drosophila Sensory Organ Precursor. Curr Biol 2013; 23:581-7. [DOI: 10.1016/j.cub.2013.02.020] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2012] [Revised: 12/10/2012] [Accepted: 02/08/2013] [Indexed: 10/27/2022]
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Couturier L, Mazouni K, Schweisguth F. Numb localizes at endosomes and controls the endosomal sorting of notch after asymmetric division in Drosophila. Curr Biol 2013; 23:588-93. [PMID: 23523245 DOI: 10.1016/j.cub.2013.03.002] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2012] [Revised: 02/04/2013] [Accepted: 03/01/2013] [Indexed: 01/05/2023]
Abstract
Numb acts as a cell-fate determinant during asymmetric and stem cell divisions in both vertebrates and invertebrates [1, 2]. In Drosophila, Numb is unequally segregated in asymmetrically dividing sensory organ precursor cells (SOPs). Numb is inherited by the pIIb cell (Notch OFF) and is absent from the pIIa cell (Notch ON) [3, 4]. Numb is required to establish directional Notch signaling during cytokinesis [3, 5-7]. Using real-time imaging of a functional GFP-tagged Numb, we show that Numb relocalizes during cytokinesis from the basal cortex of pIIb to subapical endosomes. This relocalization appeared to depend on its interaction with the α-adaptin [8, 9]. Live imaging of Sanpodo (Spdo), a membrane protein interacting with Numb and regulating the trafficking of Notch [6, 7, 10-15], revealed that Spdo is internalized during cytokinesis and coaccumulates with Numb in pIIb endosomes. Using a GFP-tagged Notch [6], we found that Notch coaccumulates with Spdo in a Numb-dependent manner in these pIIb endosomes. Numb was, however, dispensable for the internalization of Notch and Spdo. We propose that Numb interacts with internalized Spdo-Notch oligomers at sorting endosomes and inhibits the recycling of Notch, thereby creating an asymmetry in Notch distribution along the pIIa-pIIb interface and regulating binary fate choice.
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Affiliation(s)
- Lydie Couturier
- Developmental and Stem Cell Biology Department, Institut Pasteur, 75015 Paris, France
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Li X, Chen B, Yoshina S, Cai T, Yang F, Mitani S, Wang X. Inactivation of Caenorhabditis elegans aminopeptidase DNPP-1 restores endocytic sorting and recycling in tat-1 mutants. Mol Biol Cell 2013; 24:1163-75. [PMID: 23427264 PMCID: PMC3623637 DOI: 10.1091/mbc.e12-10-0730] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
This study identifies the Caenorhabditis elegans aspartyl aminopeptidase DNPP-1 as a regulator of endocytic sorting and recycling. The data reveal the involvement of an aminopeptidase in regulating endocytic sorting and recycling and suggest its possible roles in peptide signaling and/or protein metabolism in these processes. In Caenorhabditis elegans, the P4-ATPase TAT-1 and its chaperone, the Cdc50 family protein CHAT-1, maintain membrane phosphatidylserine (PS) asymmetry, which is required for membrane tubulation during endocytic sorting and recycling. Loss of tat-1 and chat-1 disrupts endocytic sorting, leading to defects in both cargo recycling and degradation. In this study, we identified the C. elegans aspartyl aminopeptidase DNPP-1, loss of which suppresses the sorting and recycling defects in tat-1 mutants without reversing the PS asymmetry defect. We found that tubular membrane structures containing recycling cargoes were restored in dnpp-1 tat-1 double mutants and that these tubules overlap with RME-1–positive recycling endosomes. The restoration of the tubular structures in dnpp-1 tat-1 mutants requires normal functions of RAB-5, RAB-10, and RME-1. In tat-1 mutants, we observed alterations in membrane surface charge and targeting of positively charged proteins that were reversed by loss of dnpp-1. DNPP-1 displays a specific aspartyl aminopeptidase activity in vitro, and its enzymatic activity is required for its function in vivo. Our data reveal the involvement of an aminopeptidase in regulating endocytic sorting and recycling and suggest possible roles of peptide signaling and/or protein metabolism in these processes.
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Affiliation(s)
- Xin Li
- College of Biological Sciences, China Agricultural University, Beijing 100094, China
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15
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Hanna M, Wang L, Audhya A. Worming our way in and out of the Caenorhabditis elegans germline and developing embryo. Traffic 2013; 14:471-8. [PMID: 23331906 DOI: 10.1111/tra.12044] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2012] [Revised: 01/11/2013] [Accepted: 01/17/2013] [Indexed: 12/18/2022]
Abstract
The germline and embryo of the nematode Caenorhabditis elegans have emerged as powerful model systems to study membrane dynamics in an intact, developing animal. In large part, this is due to the architecture of the reproductive system, which necessitates de novo membrane and organelle biogenesis within the stem cell niche to drive compartmentalization throughout the gonad syncytium. Additionally, membrane reorganization events during oocyte maturation and fertilization have been demonstrated to be highly stereotypic, facilitating the development of quantitative assays to measure the impact of perturbations on protein transport. This review will focus on regulatory mechanisms that govern protein trafficking, which have been elucidated using a combination of C. elegans genetics, biochemistry and high-resolution microscopy. Collectively, studies using the simple worm highlight an important niche that the organism holds to define new pathways that regulate vesicle transport, many of which appear to be absent in unicellular systems but remain highly conserved in mammals.
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Affiliation(s)
- Michael Hanna
- Department of Biomolecular Chemistry, University of Wisconsin-Madison Medical School, 440 Henry Mall, Madison, WI 53706, USA
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Krieger JR, Taylor P, Gajadhar AS, Guha A, Moran MF, McGlade CJ. Identification and selected reaction monitoring (SRM) quantification of endocytosis factors associated with Numb. Mol Cell Proteomics 2012; 12:499-514. [PMID: 23211419 DOI: 10.1074/mcp.m112.020768] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Numb is an endocytic adaptor protein that regulates the endocytosis and trafficking of transmembrane receptors including Notch, E-cadherin, and integrins. Vertebrate Numb is alternatively spliced at exons 3 and 9 to give rise to four protein isoforms. Expression of these isoforms varies at different developmental stages, and although the function of Numb isoforms containing exon 3 has been studied, the role of exon 9 inclusion has not been shown. Here we use affinity purification and tandem mass spectrometry to identify Numb associated proteins, including novel interactions with REPS1, BMP2K, and BCR. In vitro binding measurements indicated exon 9-independent Numb interaction with REPS1 and Eps15 EH domains. Selected reaction monitoring mass spectrometry was used to quantitatively compare the proteins associated with the p72 and p66 Numb isoforms, which differ by the exon 9 region. This showed that significantly more EPS15 and three AP-2 subunit proteins bound Numb isoforms containing exon 9. The EPS15 preference for exon 9-containing Numb was confirmed in intact cells by using a proximity ligation assay. Finally, we used multiplexed selected reaction monitoring mass spectrometry to assess the dynamic regulation of Numb association with endocytic proteins. Numb hyper-phosphorylation resulted in disassociation of Numb endocytic complexes, while inhibition of endocytosis did not alter Numb association with the AP-2 complex but altered recruitment of EPS15, REPS1, and BMP2K. Hence, quantitative mass spectrometric analysis of Numb protein-protein interactions has provided new insights into the assembly and regulation of protein complexes important in development and cancer.
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Affiliation(s)
- Jonathan R Krieger
- Department of Medical Biophysics, University of Toronto, Toronto, Ontario, M5G 2M9, Canada
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Different endocytic functions of AGEF-1 in C. elegans coelomocytes. Biochim Biophys Acta Gen Subj 2012; 1820:829-40. [PMID: 22446376 DOI: 10.1016/j.bbagen.2012.03.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2011] [Revised: 03/04/2012] [Accepted: 03/08/2012] [Indexed: 02/05/2023]
Abstract
BACKGROUND ADP-ribosylation factors (ARFs) are a family of small GTP-binding proteins that play roles in membrane dynamics and vesicle trafficking. AGEF-1, which is thought to act as a guanine nucleotide exchange factor of class I ARFs, is required for caveolin-1 body formation and receptor-mediated endocytosis in oocytes of Caenorhabditis elegans. This study explores additional roles of AGEF-1 in endocytic transport. METHODS agef-1 expression was knocked down by using RNAi in C. elegans. Markers that allow analysis of endocytic transport in scavenger cells were investigated for studying the effect of AGEF-1 on different steps of membrane transport. RESULTS Knockdown of AGEF-1 levels results in two apparent trafficking defects in coelomocytes of C. elegans. First, there is a delay in the uptake of solutes from the extracellular medium. Second, there is a dramatic enlargement of the sizes of lysosomes, even though lysosomal acidification is normal and degradation still occurs. CONCLUSION Our results suggest that AGEF-1 regulates endosome/lysosome fusion or fission events, in addition to earlier steps in endocytic transport. GENERAL SIGNIFICANCE AGEF-1 is the first identified GTPase regulator that functions at the lysosome fusion or fission stage of the endocytic pathway. Our study provides insight into lysosome dynamics in C. elegans.
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Nilsson L, Jonsson E, Tuck S. Caenorhabditis elegans numb inhibits endocytic recycling by binding TAT-1 aminophospholipid translocase. Traffic 2011; 12:1839-49. [PMID: 21917090 DOI: 10.1111/j.1600-0854.2011.01271.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Numb regulates endocytosis in many metazoans, but the mechanism by which it functions is not completely understood. Here we report that the Caenorhabditis elegans Numb ortholog, NUM-1A, a regulator of endocytic recycling, binds the C isoform of transbilayer amphipath transporter-1 (TAT-1), a P4 family adenosine triphosphatase and putative aminophospholipid translocase that is required for proper endocytic trafficking. We demonstrate that TAT-1 is differentially spliced during development and that TAT-1C-specific splicing occurs in the intestine where NUM-1A is known to function. NUM-1A and TAT-1C colocalize in vivo. We have mapped the binding site to an NXXF motif in TAT-1C. This motif is not required for TAT-1C function but is required for NUM-1A's ability to inhibit recycling. We demonstrate that num-1A and tat-1 defects are both suppressed by the loss of the activity of PSSY-1, a phosphatidylserine (PS) synthase. PS is mislocalized in intestinal cells with defects in tat-1 or num-1A function. We propose that NUM-1A inhibits recycling by inhibiting TAT-1C's ability to translocate PS across the membranes of recycling endosomes.
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Affiliation(s)
- Lars Nilsson
- Umeå Center for Molecular Medicine, Umeå University, SE-901 87 Umeå, Sweden
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19
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Ruck A, Attonito J, Garces KT, Núnez L, Palmisano NJ, Rubel Z, Bai Z, Nguyen KC, Sun L, Grant BD, Hall DH, Meléndez A. The Atg6/Vps30/Beclin 1 ortholog BEC-1 mediates endocytic retrograde transport in addition to autophagy in C. elegans. Autophagy 2011; 7:386-400. [PMID: 21183797 PMCID: PMC3108013 DOI: 10.4161/auto.7.4.14391] [Citation(s) in RCA: 99] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2010] [Revised: 12/05/2010] [Accepted: 12/06/2010] [Indexed: 02/05/2023] Open
Abstract
Autophagy and endocytosis are dynamic and tightly regulated processes that contribute to many fundamental aspects of biology including survival, longevity, and development. However, the molecular links between autophagy and endocytosis are not well understood. Here, we report that BEC-1, the C. elegans ortholog of Atg6/Vps30/Beclin1, a key regulator of the autophagic machinery, also contributes to endosome function. In particular we identify a defect in retrograde transport from endosomes to the Golgi in bec-1 mutants. MIG-14/Wntless is normally recycled from endosomes to the Golgi through the action of the retromer complex and its associated factor RME-8. Lack of retromer or RME-8 activity results in the aberrant transport of MIG-14/Wntless to the lysosome where it is degraded. Similarly, we find that lack of bec-1 also results in mislocalization and degradation of MIG-14::GFP, reduced levels of RME-8 on endosomal membranes, and the accumulation of morphologically abnormal endosomes. A similar phenotype was observed in animals treated with dsRNA against vps-34. We further identify a requirement for BEC-1 in the clearance of apoptotic corpses in the hermaphrodite gonad, suggesting a role for BEC-1 in phagosome maturation, a process that appears to depend upon retrograde transport. In addition, autophagy genes may also be required for cell corpse clearance, as we find that RNAi against atg-18 or unc-51 also results in a lack of cell corpse clearance.
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Affiliation(s)
- Alexander Ruck
- Department of Biology; Queens College; Flushing, NY USA
- The Graduate Center; The City University of New York; New York, NY USA
| | - John Attonito
- Department of Biology; Queens College; Flushing, NY USA
| | | | - Lizbeth Núnez
- Department of Biology; Queens College; Flushing, NY USA
| | - Nicholas J Palmisano
- Department of Biology; Queens College; Flushing, NY USA
- The Graduate Center; The City University of New York; New York, NY USA
| | - Zahava Rubel
- Department of Biology; Queens College; Flushing, NY USA
| | - Zhiyong Bai
- Department of Molecular Biology and Biochemistry; Rutgers University; Piscataway, NJ USA
| | - Ken C.Q Nguyen
- Center for C. elegans Anatomy; Albert Einstein College of Medicine; Bronx, NY USA
| | - Lei Sun
- Center for C. elegans Anatomy; Albert Einstein College of Medicine; Bronx, NY USA
- Center for Biological Imaging; Institute of Biophysics; Chinese Academy of Sciences; Beijing, China
| | - Barth D Grant
- Department of Molecular Biology and Biochemistry; Rutgers University; Piscataway, NJ USA
| | - David H Hall
- Center for C. elegans Anatomy; Albert Einstein College of Medicine; Bronx, NY USA
| | - Alicia Meléndez
- Department of Biology; Queens College; Flushing, NY USA
- The Graduate Center; The City University of New York; New York, NY USA
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20
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Pece S, Confalonieri S, R Romano P, Di Fiore PP. NUMB-ing down cancer by more than just a NOTCH. BIOCHIMICA ET BIOPHYSICA ACTA 2011; 1815:26-43. [PMID: 20940030 DOI: 10.1016/j.bbcan.2010.10.001] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2010] [Revised: 09/30/2010] [Accepted: 10/02/2010] [Indexed: 02/07/2023]
Abstract
The protein Numb does not live up to its name. This passive-sounding protein is anything but spent. Originally identified as a cell-fate determinant in Drosophila development, Numb received a good deal of attention as an inhibitor of the Notch receptor signaling pathway. It turns out, however, that Numb does a lot more than simply regulate Notch. It has been implicated in a variety of biochemical pathways connected with signaling (it regulates Notch-, Hedgehog- and TP53-activated pathways), endocytosis (it is involved in cargo internalization and recycling), determination of polarity (it interacts with the PAR complex, and regulates adherens and tight junctions), and ubiquitination (it exploits this mechanism to regulate protein function and stability). This complex biochemical network lies at the heart of Numb's involvement in diverse cellular phenotypes, including cell fate developmental decisions, maintenance of stem cell compartments, regulation of cell polarity and adhesion, and migration. Considering its multifaceted role in cellular homeostasis, it is not surprising that Numb has been implicated in cancer as a tumor suppressor. Our major goal here is to explain the cancer-related role of Numb based on our understanding of its role in cell physiology. We will attempt to do this by reviewing the present knowledge of Numb at the biochemical and functional level, and by integrating its apparently heterogeneous functions into a unifying scenario, based on our recently proposed concept of the "endocytic matrix". Finally, we will discuss the role of Numb in the maintenance of the normal stem cell compartment, as a starting point to interpret the tumor suppressor function of Numb in the context of the cancer stem cell hypothesis.
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Affiliation(s)
- Salvatore Pece
- Fondazione Istituto FIRC di Oncologia Molecolare, Via Adamello 16, 20139, Milan, Italy
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21
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Denver DR, Howe DK, Wilhelm LJ, Palmer CA, Anderson JL, Stein KC, Phillips PC, Estes S. Selective sweeps and parallel mutation in the adaptive recovery from deleterious mutation in Caenorhabditis elegans. Genome Res 2010; 20:1663-71. [PMID: 21036923 DOI: 10.1101/gr.108191.110] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Deleterious mutation poses a serious threat to human health and the persistence of small populations. Although adaptive recovery from deleterious mutation has been well-characterized in prokaryotes, the evolutionary mechanisms by which multicellular eukaryotes recover from deleterious mutation remain unknown. We applied high-throughput DNA sequencing to characterize genomic divergence patterns associated with the adaptive recovery from deleterious mutation using a Caenorhabditis elegans recovery-line system. The C. elegans recovery lines were initiated from a low-fitness mutation-accumulation (MA) line progenitor and allowed to independently evolve in large populations (N ∼ 1000) for 60 generations. All lines rapidly regained levels of fitness similar to the wild-type (N2) MA line progenitor. Although there was a near-zero probability of a single mutation fixing due to genetic drift during the recovery experiment, we observed 28 fixed mutations. Cross-generational analysis showed that all mutations went from undetectable population-level frequencies to a fixed state in 10-20 generations. Many recovery-line mutations fixed at identical timepoints, suggesting that the mutations, if not beneficial, hitchhiked to fixation during selective sweep events observed in the recovery lines. No MA line mutation reversions were detected. Parallel mutation fixation was observed for two sites in two independent recovery lines. Analysis using a C. elegans interactome map revealed many predicted interactions between genes with recovery line-specific mutations and genes with previously accumulated MA line mutations. Our study suggests that recovery-line mutations identified in both coding and noncoding genomic regions might have beneficial effects associated with compensatory epistatic interactions.
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Affiliation(s)
- Dee R Denver
- Department of Zoology, Oregon State University, Corvallis, Oregon 97331, USA.
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22
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Abstract
Endocytosis has long been thought of as simply a way for cells to internalize nutrients and membrane-associated molecules. But an explosive growth in knowledge has given a new dimension to our understanding of this process. It now seems that endocytosis is a master organizer of signalling circuits, with one of its main roles being the resolution of signals in space and time. Many of the functions of endocytosis that are emerging from recent research cannot yet be reconciled with the canonical view of intracellular trafficking but, instead, point to endocytosis being integrated at a deeper level in the cellular 'master plan' (the cellular network of signalling circuits that lie at the base of the cell's make-up). Deconvolution of this level, which we call the 'endocytic matrix', might uncover a fundamental aspect of how a cell is built.
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23
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Tong X, Zitserman D, Serebriiskii I, Andrake M, Dunbrack R, Roegiers F. Numb independently antagonizes Sanpodo membrane targeting and Notch signaling in Drosophila sensory organ precursor cells. Mol Biol Cell 2010; 21:802-10. [PMID: 20053677 PMCID: PMC2828966 DOI: 10.1091/mbc.e09-09-0831] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
How Numb regulates Notch signaling following asymmetric cell division is unclear. Numb directly binds and blocks membrane localization of Sanpodo, a protein essential for Notch signaling in Drosophila. Uncoupling Sanpodo from Numb results in accumulation of Sanpodo at the membrane, but this surprisingly does not appear to promote Notch signaling. In Drosophila, mitotic neural progenitor cells asymmetrically segregate the cell fate determinant Numb in order to block Notch signaling in only one of the two daughter cells. Sanpodo, a membrane protein required for Notch signaling in asymmetrically dividing cells, is sequestered from the plasma membrane to intracellular vesicles in a Numb-dependent way after neural progenitor cell mitosis. However, the significance of Numb-dependent Sanpodo regulation is unclear. In this study, we conducted a structure–function analysis to identify the determinants of Sanpodo targeting in vivo. We identified an NPAF motif in the amino-terminal cytoplasmic tail of Sanpodo, which is conserved among insect Sanpodo homologues. The Sanpodo NPAF motif is predicted to bind directly to the Numb phosphotyrosine-binding domain and is critical for Numb binding in vitro. Deletion or mutation of the NPAF motif results in accumulation of Sanpodo at the plasma membrane in Numb-positive cells in vivo. Genetic analysis of Sanpodo NPAF mutants shows that Numb-dependent Sanpodo endocytic targeting can be uncoupled from Notch signaling regulation. Our findings demonstrate that Sanpodo contains an evolutionarily conserved motif that has been linked to Numb-dependent regulation in vertebrates and further support the model that Numb regulates Notch signaling independently of Sanpodo membrane trafficking in neural progenitor cells.
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Affiliation(s)
- Xin Tong
- Fox Chase Cancer Center, Philadelphia, PA 19111, USA
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McGill MA, Dho SE, Weinmaster G, McGlade CJ. Numb regulates post-endocytic trafficking and degradation of Notch1. J Biol Chem 2009; 284:26427-38. [PMID: 19567869 DOI: 10.1074/jbc.m109.014845] [Citation(s) in RCA: 158] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Notch is a transmembrane receptor that controls cell fate decisions during development and tissue homeostasis. Both activation and attenuation of the Notch signal are tightly regulated by endocytosis. The adaptor protein Numb acts as an inhibitor of Notch and is known to function within the intracellular trafficking pathways. However, a role for Numb in regulating Notch trafficking has not been defined. Here we show that mammalian Notch1 is constitutively internalized and trafficked to both recycling and late endosomal compartments, and we demonstrate that changes in Numb expression alter the dynamics of Notch1 trafficking. Overexpression of Numb promotes sorting of Notch1 through late endosomes for degradation, whereas depletion of Numb facilitates Notch1 recycling. Numb mutants that do not interact with the ubiquitin-protein isopeptide ligase, Itch, or that lack motifs important for interaction with endocytic proteins fail to promote Notch1 degradation. Our data suggest that Numb inhibits Notch1 activity by regulating post-endocytic sorting events that lead to Notch1 degradation.
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Affiliation(s)
- Melanie A McGill
- Department of Medical Biophysics, University of Toronto, Toronto, Ontario M5G 1X8, Canada
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25
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Manipulating the Caenorhabditis elegans genome using mariner transposons. Genetica 2009; 138:541-9. [PMID: 19347589 DOI: 10.1007/s10709-009-9362-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2009] [Accepted: 03/20/2009] [Indexed: 12/16/2022]
Abstract
Tc1, one of the founding members of the Tc1/mariner transposon superfamily, was identified in the nematode Caenorhabditis elegans more than 25 years ago. Over the years, Tc1 and other endogenous mariner transposons became valuable tools for mutagenesis and targeted gene inactivation in C. elegans. However, transposition is naturally repressed in the C. elegans germline by an RNAi-like mechanism, necessitating the use of mutant strains in which transposition was globally derepressed, which causes drawbacks such as uncontrolled proliferation of the transposons in the genome and accumulation of background mutations. The more recent mobilization of the Drosophila mariner transposon Mos1 in the C. elegans germline circumvented the problems inherent to endogenous transposons. Mos1 transposition strictly depends on the expression of the Mos transposase, which can be controlled in the germline using inducible promoters. First, Mos1 can be used for insertional mutagenesis. The mobilization of Mos1 copies present on an extrachromosomal array results in the generation of a small number of Mos1 genomic insertions that can be rapidly cloned by inverse PCR. Second, Mos1 insertions can be used for genome engineering. Triggering the excision of a genomic Mos1 insertion causes a chromosomal break, which can be repaired by transgene-instructed gene conversion. This process is used to introduce specific changes in a given gene, such as point mutations, deletions or insertions of a tag, and to create single-copy transgenes.
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26
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Parker S, Walker DS, Ly S, Baylis HA. Caveolin-2 is required for apical lipid trafficking and suppresses basolateral recycling defects in the intestine of Caenorhabditis elegans. Mol Biol Cell 2009; 20:1763-71. [PMID: 19158391 PMCID: PMC2655242 DOI: 10.1091/mbc.e08-08-0837] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2008] [Revised: 12/08/2008] [Accepted: 01/13/2009] [Indexed: 12/30/2022] Open
Abstract
Caveolins are plasma membrane-associated proteins that colocalize with, and stabilize caveolae. Their functions remain unclear although they are known to be involved in specific events in cell signaling and endocytosis. Caenorhabditis elegans encodes two caveolin genes, cav-1 and cav-2. We show that cav-2 is expressed in the intestine where it is localized to the apical membrane and in intracellular bodies. Using the styryl dye FM4-64 and BODIPY-labeled lactosylceramide, we show that the intestinal cells of cav-2 animals are defective in the apical uptake of lipid markers. These results suggest parallels with the function of caveolins in lipid homeostasis in mammals. We also show that CAV-2 depletion suppresses the abnormal accumulation of vacuoles that result from defective basolateral recycling in rme-1 and rab-10 mutants. Analysis of fluorescent markers of basolateral endocytosis and recycling suggest that endocytosis is normal in cav-2 mutants and thus, that the suppression of basolateral recycling defects in cav-2 mutants is due to changes in intracellular trafficking pathways. Finally, cav-2 mutants also have abnormal trafficking of yolk proteins. Taken together, these data indicate that caveolin-2 is an integral component of the trafficking network in the intestinal cells of C. elegans.
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Affiliation(s)
- Scott Parker
- Department of Zoology, University of Cambridge, Downing Street, Cambridge, CB2 3EJ, United Kingdom
| | - Denise S. Walker
- Department of Zoology, University of Cambridge, Downing Street, Cambridge, CB2 3EJ, United Kingdom
| | - Sung Ly
- Department of Zoology, University of Cambridge, Downing Street, Cambridge, CB2 3EJ, United Kingdom
| | - Howard A. Baylis
- Department of Zoology, University of Cambridge, Downing Street, Cambridge, CB2 3EJ, United Kingdom
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