101
|
van der Beek J, Jonker C, van der Welle R, Liv N, Klumperman J. CORVET, CHEVI and HOPS – multisubunit tethers of the endo-lysosomal system in health and disease. J Cell Sci 2019; 132:132/10/jcs189134. [DOI: 10.1242/jcs.189134] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
ABSTRACT
Multisubunit tethering complexes (MTCs) are multitasking hubs that form a link between membrane fusion, organelle motility and signaling. CORVET, CHEVI and HOPS are MTCs of the endo-lysosomal system. They regulate the major membrane flows required for endocytosis, lysosome biogenesis, autophagy and phagocytosis. In addition, individual subunits control complex-independent transport of specific cargoes and exert functions beyond tethering, such as attachment to microtubules and SNARE activation. Mutations in CHEVI subunits lead to arthrogryposis, renal dysfunction and cholestasis (ARC) syndrome, while defects in CORVET and, particularly, HOPS are associated with neurodegeneration, pigmentation disorders, liver malfunction and various forms of cancer. Diseases and phenotypes, however, vary per affected subunit and a concise overview of MTC protein function and associated human pathologies is currently lacking. Here, we provide an integrated overview on the cellular functions and pathological defects associated with CORVET, CHEVI or HOPS proteins, both with regard to their complexes and as individual subunits. The combination of these data provides novel insights into how mutations in endo-lysosomal proteins lead to human pathologies.
Collapse
Affiliation(s)
- Jan van der Beek
- Section Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, Institute for Biomembranes, Utrecht University, Utrecht 3584 CX, The Netherlands
| | - Caspar Jonker
- Section Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, Institute for Biomembranes, Utrecht University, Utrecht 3584 CX, The Netherlands
| | - Reini van der Welle
- Section Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, Institute for Biomembranes, Utrecht University, Utrecht 3584 CX, The Netherlands
| | - Nalan Liv
- Section Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, Institute for Biomembranes, Utrecht University, Utrecht 3584 CX, The Netherlands
| | - Judith Klumperman
- Section Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, Institute for Biomembranes, Utrecht University, Utrecht 3584 CX, The Netherlands
| |
Collapse
|
102
|
Homma Y, Kinoshita R, Kuchitsu Y, Wawro PS, Marubashi S, Oguchi ME, Ishida M, Fujita N, Fukuda M. Comprehensive knockout analysis of the Rab family GTPases in epithelial cells. J Cell Biol 2019; 218:2035-2050. [PMID: 31072826 PMCID: PMC6548125 DOI: 10.1083/jcb.201810134] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Revised: 02/26/2019] [Accepted: 04/12/2019] [Indexed: 12/23/2022] Open
Abstract
Rab small GTPases (∼60 genes in mammals) are the master regulators of intracellular membrane trafficking. Homma et al. establish a comprehensive collection of knockout epithelial cell lines for all the mammalian Rabs, revealing that Rab6 is required for basement membrane formation and soluble cargo secretion. The Rab family of small GTPases comprises the largest number of proteins (∼60 in mammals) among the regulators of intracellular membrane trafficking, but the precise function of many Rabs and the functional redundancy and diversity of Rabs remain largely unknown. Here, we generated a comprehensive collection of knockout (KO) MDCK cells for the entire Rab family. We knocked out closely related paralogs simultaneously (Rab subfamily knockout) to circumvent functional compensation and found that Rab1A/B and Rab5A/B/C are critical for cell survival and/or growth. In addition, we demonstrated that Rab6-KO cells lack the basement membrane, likely because of the inability to secrete extracellular matrix components. Further analysis revealed the general requirement of Rab6 for secretion of soluble cargos. Transport of transmembrane cargos to the plasma membrane was also significantly delayed in Rab6-KO cells, but the phenotype was relatively mild. Our Rab-KO collection, which shares the same background, would be a valuable resource for analyzing a variety of membrane trafficking events.
Collapse
Affiliation(s)
- Yuta Homma
- Laboratory of Membrane Trafficking Mechanisms, Department of Integrative Life Sciences, Graduate School of Life Sciences, Tohoku University, Miyagi, Japan
| | - Riko Kinoshita
- Laboratory of Membrane Trafficking Mechanisms, Department of Integrative Life Sciences, Graduate School of Life Sciences, Tohoku University, Miyagi, Japan
| | - Yoshihiko Kuchitsu
- Laboratory of Membrane Trafficking Mechanisms, Department of Integrative Life Sciences, Graduate School of Life Sciences, Tohoku University, Miyagi, Japan
| | - Paulina S Wawro
- Laboratory of Membrane Trafficking Mechanisms, Department of Integrative Life Sciences, Graduate School of Life Sciences, Tohoku University, Miyagi, Japan
| | - Soujiro Marubashi
- Laboratory of Membrane Trafficking Mechanisms, Department of Integrative Life Sciences, Graduate School of Life Sciences, Tohoku University, Miyagi, Japan
| | - Mai E Oguchi
- Laboratory of Membrane Trafficking Mechanisms, Department of Integrative Life Sciences, Graduate School of Life Sciences, Tohoku University, Miyagi, Japan
| | - Morié Ishida
- Laboratory of Membrane Trafficking Mechanisms, Department of Integrative Life Sciences, Graduate School of Life Sciences, Tohoku University, Miyagi, Japan
| | - Naonobu Fujita
- Laboratory of Membrane Trafficking Mechanisms, Department of Integrative Life Sciences, Graduate School of Life Sciences, Tohoku University, Miyagi, Japan
| | - Mitsunori Fukuda
- Laboratory of Membrane Trafficking Mechanisms, Department of Integrative Life Sciences, Graduate School of Life Sciences, Tohoku University, Miyagi, Japan
| |
Collapse
|
103
|
Jackson CL. Lipid droplet biogenesis. Curr Opin Cell Biol 2019; 59:88-96. [PMID: 31075519 DOI: 10.1016/j.ceb.2019.03.018] [Citation(s) in RCA: 73] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Revised: 03/24/2019] [Accepted: 03/29/2019] [Indexed: 11/18/2022]
Abstract
Lipid droplets (LDs) store neutral lipids in their core as an energy source when nutrients are scarce. The center of an LD is hydrophobic, and hence it is surrounded by a phospholipid monolayer, unlike other organelles that have an aqueous interior and are bounded by a phospholipid bilayer. LDs arise from the ER, where neutral lipid synthesis enzymes are localized. A combination of biophysical analysis and modeling, in vitro reconstitution and cell biological analyses has provided a great deal of information over the past few years on the process of LD biogenesis from the ER. In addition to lipid composition, four protein families (seipin proteins, perilipins, FIT proteins and ER shaping proteins) are crucial for LD biogenesis. Recent studies have shown that LDs preferentially arise, along with peroxisomes, at special ER sites marked by the reticulon-like Pex30/MCTP2 protein. New functions for perilipins and FIT family proteins have been uncovered, and the cryo-electron microscopy structure of seipin coupled with high resolution imaging in cells has provided a more comprehensive picture of its function in LD biogenesis. Seipin, along with other proteins such as Rab18 and its effector NRZ, have been shown to carry out their functions at least in part through regulation of ER-LD contact sites, whose establishment and maintenance have emerged as an essential component of LD biogenesis and maturation.
Collapse
Affiliation(s)
- Catherine L Jackson
- Institut Jacques Monod, UMR7592 CNRS Université Paris-Diderot, Sorbonne Paris Cité, Paris, France.
| |
Collapse
|
104
|
Dejgaard SY, Presley JF. Rab18: new insights into the function of an essential protein. Cell Mol Life Sci 2019; 76:1935-1945. [PMID: 30830238 PMCID: PMC11105521 DOI: 10.1007/s00018-019-03050-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2018] [Revised: 02/14/2019] [Accepted: 02/19/2019] [Indexed: 12/14/2022]
Abstract
Rab18 is one of the small number of conserved Rab proteins which have been traced to the last eukaryotic common ancestor. It is found in organisms ranging from humans to trypanosomes, and localizes to multiple organelles, including most notably endoplasmic reticulum and lipid droplets. In humans, absence of Rab18 leads to a severe illness known as Warburg-Micro syndrome. Despite this evidence that Rab18 is essential, its role in cells remains mysterious. However, recent studies identifying effectors and interactors of Rab18, are now shedding light on its mechanism of action, suggesting functions related to organelle tethering and to autophagy. In this review, we examine the variety of roles proposed for Rab18 with a focus on new evidence giving insights into the molecular mechanisms it utilizes. Based on this summary of our current understanding, we identify priority areas for further research.
Collapse
Affiliation(s)
- Selma Yilmaz Dejgaard
- Department of Medical Biology, Near East University, Nicosia, Cyprus
- Department of Anatomy and Cell Biology, McGill University, 3640 University Street, Montreal, QC, H3A 0C7, Canada
| | - John F Presley
- Department of Anatomy and Cell Biology, McGill University, 3640 University Street, Montreal, QC, H3A 0C7, Canada.
| |
Collapse
|
105
|
Gershlick DC, Ishida M, Jones JR, Bellomo A, Bonifacino JS, Everman DB. A neurodevelopmental disorder caused by mutations in the VPS51 subunit of the GARP and EARP complexes. Hum Mol Genet 2019; 28:1548-1560. [PMID: 30624672 PMCID: PMC6489419 DOI: 10.1093/hmg/ddy423] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Revised: 11/27/2018] [Accepted: 12/02/2018] [Indexed: 11/12/2022] Open
Abstract
Golgi-associated retrograde protein (GARP) and endosome-associated recycling protein (EARP) are related heterotetrameric complexes that associate with the cytosolic face of the trans-Golgi network and recycling endosomes, respectively. At these locations, GARP and EARP function to promote the fusion of endosome-derived transport carriers with their corresponding compartments. GARP and EARP share three subunits, VPS51, VPS52 and VPS53, and each has an additional complex-specific subunit, VPS54 or VPS50, respectively. The role of these complexes in human physiology, however, remains poorly understood. By exome sequencing, we have identified compound heterozygous mutations in the gene encoding the shared GARP/EARP subunit VPS51 in a 6-year-old patient with severe global developmental delay, microcephaly, hypotonia, epilepsy, cortical vision impairment, pontocerebellar abnormalities, failure to thrive, liver dysfunction, lower extremity edema and dysmorphic features. The mutation in one allele causes a frameshift that produces a longer but highly unstable protein that is degraded by the proteasome. In contrast, the other mutant allele produces a protein with a single amino acid substitution that is stable but assembles less efficiently with the other GARP/EARP subunits. Consequently, skin fibroblasts from the patient have reduced levels of fully assembled GARP and EARP complexes. Likely because of this deficiency, the patient's fibroblasts display altered distribution of the cation-independent mannose 6-phosphate receptor, which normally sorts acid hydrolases to lysosomes. Furthermore, a fraction of the patient's fibroblasts exhibits swelling of lysosomes. These findings thus identify a novel genetic locus for a neurodevelopmental disorder and highlight the critical importance of GARP/EARP function in cellular and organismal physiology.
Collapse
Affiliation(s)
- David C Gershlick
- Cell Biology and Neurobiology Branch, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | - Morié Ishida
- Cell Biology and Neurobiology Branch, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | | | | | - Juan S Bonifacino
- Cell Biology and Neurobiology Branch, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | | |
Collapse
|
106
|
Koike S, Jahn R. SNAREs define targeting specificity of trafficking vesicles by combinatorial interaction with tethering factors. Nat Commun 2019; 10:1608. [PMID: 30962439 PMCID: PMC6453939 DOI: 10.1038/s41467-019-09617-9] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Accepted: 03/15/2019] [Indexed: 02/06/2023] Open
Abstract
Membrane traffic operates by vesicles that bud from precursor organelles and are transported to their target compartment where they dock and fuse. Targeting requires tethering factors recruited by small GTPases and phosphoinositides whereas fusion is carried out by SNARE proteins. Here we report that vesicles containing the Q-SNAREs syntaxin 13 (Stx13) and syntaxin 6 (Stx6) together are targeted to a different endosomal compartment than vesicles containing only Stx6 using injection of artificial vesicles. Targeting by Stx6 requires Vps51, a component of the GARP/EARP tethering complexes. In contrast, targeting by both Stx6 and Stx13 is governed by Vps13B identified here as tethering factor functioning in transport from early endosomes to recycling endosomes. Vps13B specifically binds to Stx13/Stx6 as well as to Rab14, Rab6, and PtdIns(3)P. We conclude that SNAREs use a combinatorial code for recruiting tethering factors, revealing a key function in targeting that is independent of SNARE pairing during fusion. Intracellular vesicle targeting is mediated by Rab GTPases that cooperate with phosphatidylinositides and SNARE proteins, which then facilitate membrane fusion. Here, the authors microinject artificial vesicles into HeLa cells and find that SNAREs play a more prominent role in targeting specificity of trafficking vesicles than previously known.
Collapse
Affiliation(s)
- Seiichi Koike
- Department of Neurobiology, Max Planck Institute for Biophysical Chemistry, Göttingen, 37077, Germany
| | - Reinhard Jahn
- Department of Neurobiology, Max Planck Institute for Biophysical Chemistry, Göttingen, 37077, Germany.
| |
Collapse
|
107
|
Drosophila Arl8 is a general positive regulator of lysosomal fusion events. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2019; 1866:533-544. [DOI: 10.1016/j.bbamcr.2018.12.011] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Revised: 12/17/2018] [Accepted: 12/21/2018] [Indexed: 12/14/2022]
|
108
|
Kuruvilla J, Bayat N, Cristobal S. Proteomic Analysis of Endothelial Cells Exposed to Ultrasmall Nanoparticles Reveals Disruption in Paracellular and Transcellular Transport. Proteomics 2019; 19:e1800228. [PMID: 30632670 DOI: 10.1002/pmic.201800228] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 11/12/2018] [Indexed: 11/10/2022]
Abstract
The large interactive surfaces of nanoparticles (NPs) increase the opportunities to develop NPs for vascular targeting. Proteomic analysis of endothelial cells exposed to NPs reveals the cellular response and turns the focus into the impairment of the endothelial permeability. Here, quantitative proteomics and transcriptome sequencing are combined to evaluate the effects of exposure to sub-lethal concentrations of TiO2 -USNPs and TiO2 -NPs on human dermal microvascular endothelial cells. Endothelial cells react to preserve the semi-permeable properties that are essential for vascular tissue fluid homeostasis, vascular development, and angiogenesis. The main impact of the exposure was alteration of functional complexes involved in cell adhesion, vesicular transport, and cytoskeletal structure. Those are the core cellular structures that are linked to the permeability and the integrity of the endothelial tissue. Moreover, the extracellular proteins uptake along wih the NPs into the endothelial cells escape the lysosomal degradation pathway. These findings improve the understanding of the interaction of NPs with endothelial cell. The effects of the studied NPs modulating cell-cell adhesion and vesicular transport can help to evaluate the distribution of NPs via intravenous administration.
Collapse
Affiliation(s)
- Jacob Kuruvilla
- Department of Clinical and Experimental Medicine, Cell Biology, Faculty of Medicine, Linköping University, Linköping, SE-58185, Sweden
| | - Narges Bayat
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, SE-10691, Sweden
| | - Susana Cristobal
- Department of Clinical and Experimental Medicine, Cell Biology, Faculty of Medicine, Linköping University, Linköping, SE-58185, Sweden.,IKERBASQUE, Basque Foundation for Science, Departments of Physiology, Faculty of Medicine and Dentistry, University of the Basque Country, Leioa, ES-48490, Spain
| |
Collapse
|
109
|
Muñoz-Braceras S, Tornero-Écija AR, Vincent O, Escalante R. VPS13A is closely associated with mitochondria and is required for efficient lysosomal degradation. Dis Model Mech 2019; 12:dmm036681. [PMID: 30709847 PMCID: PMC6398486 DOI: 10.1242/dmm.036681] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 01/22/2019] [Indexed: 12/11/2022] Open
Abstract
Members of the VPS13 family are associated with various human diseases. In particular, the loss of function of VPS13A leads to chorea-acanthocytosis (ChAc), a rare neurodegenerative disease without available curative treatments. Autophagy has been considered a promising therapeutic target because the absence of VPS13A causes a defective autophagy flux. However, the mechanistic details of this deficiency are unknown. Here, we identified Rab7A as an interactor of one of the VPS13 family members in Dictyostelium discoideum and showed that this interaction is conserved between the human homologs VPS13A and RAB7A in HeLa cells. As RAB7A is a key player in endosome trafficking, we addressed the possible function of VPS13A in endosome dynamics and lysosome degradation. Our results suggest that the decrease in autophagy observed in the absence of VPS13A may be the result of a more general defect in endocytic trafficking and lysosomal degradation. Unexpectedly, we found that VPS13A is closely localized to mitochondria, suggesting that the role of VPS13A in the endolysosomal pathway might be related to inter-organelle communication. We show that VPS13A localizes at the interface between mitochondria-endosomes and mitochondria-endoplasmic reticulum and that the presence of membrane contact sites is altered in the absence of VPS13A. Based on these findings, we propose that therapeutic strategies aimed at modulating the endolysosomal pathway could be beneficial in the treatment of ChAc.This article has an associated First Person interview with the first author of the paper.
Collapse
Affiliation(s)
- Sandra Muñoz-Braceras
- Instituto de Investigaciones Biomédicas Alberto Sols, Department of Experimental Models of Human Diseases, Consejo Superior de Investigaciones Científicas (CSIC)/Universidad Autónoma Madrid (UAM), 28029-Madrid, Spain
| | - Alba R Tornero-Écija
- Instituto de Investigaciones Biomédicas Alberto Sols, Department of Experimental Models of Human Diseases, Consejo Superior de Investigaciones Científicas (CSIC)/Universidad Autónoma Madrid (UAM), 28029-Madrid, Spain
| | - Olivier Vincent
- Instituto de Investigaciones Biomédicas Alberto Sols, Department of Experimental Models of Human Diseases, Consejo Superior de Investigaciones Científicas (CSIC)/Universidad Autónoma Madrid (UAM), 28029-Madrid, Spain
| | - Ricardo Escalante
- Instituto de Investigaciones Biomédicas Alberto Sols, Department of Experimental Models of Human Diseases, Consejo Superior de Investigaciones Científicas (CSIC)/Universidad Autónoma Madrid (UAM), 28029-Madrid, Spain
| |
Collapse
|
110
|
Nian FS, Li LL, Cheng CY, Wu PC, Lin YT, Tang CY, Ren BS, Tai CY, Fann MJ, Kao LS, Hong CJ, Tsai JW. Rab18 Collaborates with Rab7 to Modulate Lysosomal and Autophagy Activities in the Nervous System: an Overlapping Mechanism for Warburg Micro Syndrome and Charcot-Marie-Tooth Neuropathy Type 2B. Mol Neurobiol 2019; 56:6095-6105. [PMID: 30721447 DOI: 10.1007/s12035-019-1471-z] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Accepted: 01/10/2019] [Indexed: 01/24/2023]
Abstract
Mutations in RAB18, a member of small G protein, cause Warburg micro syndrome (WARBM), whose clinical features include vision impairment, postnatal microcephaly, and lower limb spasticity. Previously, our Rab18-/- mice exhibited hind limb weakness and spasticity as well as signs of axonal degeneration in the spinal cord and lumbar spinal nerves. However, the cellular and molecular function of RAB18 and its roles in the pathogenesis of WARBM are still not fully understood. Using immunofluorescence staining and expression of Rab18 and organelle markers, we find that Rab18 associates with lysosomes and actively traffics along neurites in cultured neurons. Interestingly, Rab18-/- neurons exhibit impaired lysosomal transport. Using autophagosome marker LC3-II, we show that Rab18 dysfunction leads to aberrant autophagy activities in neurons. Electron microscopy further reveals accumulation of lipofuscin-like granules in the dorsal root ganglion of Rab18-/- mice. Surprisingly, Rab18 colocalizes, cofractionates, and coprecipitates with the lysosomal regulator Rab7, mutations of which cause Charcot-Marie-Tooth (CMT) neuropathy type 2B. Moreover, Rab7 is upregulated in Rab18-deficient neurons, suggesting a compensatory effect. Together, our results suggest that the functions of RAB18 and RAB7 in lysosomal and autophagic activities may constitute an overlapping mechanism underlying WARBM and CMT pathogenesis in the nervous system.
Collapse
Affiliation(s)
- Fang-Shin Nian
- Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan.,Program in Molecular Medicine, National Yang-Ming University and Academia Sinica, Taipei, Taiwan
| | - Lei-Li Li
- Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan
| | - Chih-Ya Cheng
- Department of Pediatrics, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Pei-Chun Wu
- Department of Life Sciences and Institute of Genome Sciences, National Yang-Ming University, Taipei, Taiwan.,Brain Research Center, National Yang-Ming University, Taipei, Taiwan
| | - You-Tai Lin
- Department of Life Sciences and Institute of Genome Sciences, National Yang-Ming University, Taipei, Taiwan
| | - Cheng-Yung Tang
- Department of Life Sciences and Institute of Genome Sciences, National Yang-Ming University, Taipei, Taiwan
| | - Bo-Shiun Ren
- Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan
| | - Chin-Yin Tai
- Institute of Molecular Biology, Academia Sinica, Nankang, Taipei, Taiwan
| | - Ming-Ji Fann
- Department of Life Sciences and Institute of Genome Sciences, National Yang-Ming University, Taipei, Taiwan.,Brain Research Center, National Yang-Ming University, Taipei, Taiwan
| | - Lung-Sen Kao
- Department of Life Sciences and Institute of Genome Sciences, National Yang-Ming University, Taipei, Taiwan.,Brain Research Center, National Yang-Ming University, Taipei, Taiwan
| | - Chen-Jee Hong
- Brain Research Center, National Yang-Ming University, Taipei, Taiwan.,Division of Psychiatry, School of Medicine, National Yang-Ming University, Taipei, Taiwan.,Department of Psychiatry, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Jin-Wu Tsai
- Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan. .,Brain Research Center, National Yang-Ming University, Taipei, Taiwan. .,Biopotonics and Molecular Imaging Research Center, National Yang-Ming University, Taipei, Taiwan.
| |
Collapse
|
111
|
Del Olmo T, Lauzier A, Normandin C, Larcher R, Lecours M, Jean D, Lessard L, Steinberg F, Boisvert FM, Jean S. APEX2-mediated RAB proximity labeling identifies a role for RAB21 in clathrin-independent cargo sorting. EMBO Rep 2019; 20:e47192. [PMID: 30610016 PMCID: PMC6362359 DOI: 10.15252/embr.201847192] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Revised: 12/06/2018] [Accepted: 12/10/2018] [Indexed: 12/26/2022] Open
Abstract
RAB GTPases are central modulators of membrane trafficking. They are under the dynamic regulation of activating guanine exchange factors (GEFs) and inactivating GTPase-activating proteins (GAPs). Once activated, RABs recruit a large spectrum of effectors to control trafficking functions of eukaryotic cells. Multiple proteomic studies, using pull-down or yeast two-hybrid approaches, have identified a number of RAB interactors. However, due to the in vitro nature of these approaches and inherent limitations of each technique, a comprehensive definition of RAB interactors is still lacking. By comparing quantitative affinity purifications of GFP:RAB21 with APEX2-mediated proximity labeling of RAB4a, RAB5a, RAB7a, and RAB21, we find that APEX2 proximity labeling allows for the comprehensive identification of RAB regulators and interactors. Importantly, through biochemical and genetic approaches, we establish a novel link between RAB21 and the WASH and retromer complexes, with functional consequences on cargo sorting. Hence, APEX2-mediated proximity labeling of RAB neighboring proteins represents a new and efficient tool to define RAB functions.
Collapse
Affiliation(s)
- Tomas Del Olmo
- Faculté de Médecine et des Sciences de la Santé, Département d'Anatomie et de Biologie Cellulaire, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Annie Lauzier
- Faculté de Médecine et des Sciences de la Santé, Département d'Anatomie et de Biologie Cellulaire, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Caroline Normandin
- Faculté de Médecine et des Sciences de la Santé, Département d'Anatomie et de Biologie Cellulaire, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Raphaëlle Larcher
- Faculté de Médecine et des Sciences de la Santé, Département d'Anatomie et de Biologie Cellulaire, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Mia Lecours
- Faculté de Médecine et des Sciences de la Santé, Département d'Anatomie et de Biologie Cellulaire, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Dominique Jean
- Faculté de Médecine et des Sciences de la Santé, Département d'Anatomie et de Biologie Cellulaire, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Louis Lessard
- Faculté de Médecine et des Sciences de la Santé, Département d'Anatomie et de Biologie Cellulaire, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Florian Steinberg
- Center for Biological Systems Analysis (ZBSA), Faculty of Biology, Albert Ludwigs Universitaet Freiburg, Freiburg, Germany
| | - François-Michel Boisvert
- Faculté de Médecine et des Sciences de la Santé, Département d'Anatomie et de Biologie Cellulaire, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Steve Jean
- Faculté de Médecine et des Sciences de la Santé, Département d'Anatomie et de Biologie Cellulaire, Université de Sherbrooke, Sherbrooke, QC, Canada
| |
Collapse
|
112
|
Witkos TM, Chan WL, Joensuu M, Rhiel M, Pallister E, Thomas-Oates J, Mould AP, Mironov AA, Biot C, Guerardel Y, Morelle W, Ungar D, Wieland FT, Jokitalo E, Tassabehji M, Kornak U, Lowe M. GORAB scaffolds COPI at the trans-Golgi for efficient enzyme recycling and correct protein glycosylation. Nat Commun 2019; 10:127. [PMID: 30631079 PMCID: PMC6328613 DOI: 10.1038/s41467-018-08044-6] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Accepted: 12/06/2018] [Indexed: 01/08/2023] Open
Abstract
COPI is a key mediator of protein trafficking within the secretory pathway. COPI is recruited to the membrane primarily through binding to Arf GTPases, upon which it undergoes assembly to form coated transport intermediates responsible for trafficking numerous proteins, including Golgi-resident enzymes. Here, we identify GORAB, the protein mutated in the skin and bone disorder gerodermia osteodysplastica, as a component of the COPI machinery. GORAB forms stable domains at the trans-Golgi that, via interactions with the COPI-binding protein Scyl1, promote COPI recruitment to these domains. Pathogenic GORAB mutations perturb Scyl1 binding or GORAB assembly into domains, indicating the importance of these interactions. Loss of GORAB causes impairment of COPI-mediated retrieval of trans-Golgi enzymes, resulting in a deficit in glycosylation of secretory cargo proteins. Our results therefore identify GORAB as a COPI scaffolding factor, and support the view that defective protein glycosylation is a major disease mechanism in gerodermia osteodysplastica.
Collapse
Affiliation(s)
- Tomasz M Witkos
- School of Biology, Faculty of Biology, Medicine and Health, University of Manchester, The Michael Smith Building, Oxford Road, Manchester, M13 9PT, UK
| | - Wing Lee Chan
- Berlin-Brandenburg Centre for Regenerative Therapies (BCRT), Institut fuer Medizinische Genetik und Humangenetik, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, Berlin, 13353, Germany
- FG Development & Disease, Max Planck Institut fuer Molekulare Genetik, Berlin, 14195, Germany
| | - Merja Joensuu
- Cell and Molecular Biology Program, Institute of Biotechnology, University of Helsinki, Helsinki, 00014, Finland
- Clem Jones Centre of Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, Brisbane, QLD 4072, Australia
- Minerva Foundation Institute for Medical Research, 00290, Helsinki, Finland
| | - Manuel Rhiel
- Heidelberg University Biochemistry Center, Heidelberg University, Heidelberg, 69120, Germany
| | - Ed Pallister
- Department of Chemistry, University of York, York, YO10 5DG, UK
| | | | - A Paul Mould
- School of Biology, Faculty of Biology, Medicine and Health, University of Manchester, The Michael Smith Building, Oxford Road, Manchester, M13 9PT, UK
| | - Alex A Mironov
- School of Biology, Faculty of Biology, Medicine and Health, University of Manchester, The Michael Smith Building, Oxford Road, Manchester, M13 9PT, UK
| | - Christophe Biot
- Univ. Lille, CNRS, UMR 8576 - UGSF - Unité de Glycobiologie Structurale et Fonctionnelle, F-59000, Lille, France
| | - Yann Guerardel
- Univ. Lille, CNRS, UMR 8576 - UGSF - Unité de Glycobiologie Structurale et Fonctionnelle, F-59000, Lille, France
| | - Willy Morelle
- Univ. Lille, CNRS, UMR 8576 - UGSF - Unité de Glycobiologie Structurale et Fonctionnelle, F-59000, Lille, France
| | - Daniel Ungar
- Department of Biology, University of York, York, YO10 5DD, UK
| | - Felix T Wieland
- Heidelberg University Biochemistry Center, Heidelberg University, Heidelberg, 69120, Germany
| | - Eija Jokitalo
- Cell and Molecular Biology Program, Institute of Biotechnology, University of Helsinki, Helsinki, 00014, Finland
| | - May Tassabehji
- School of Biology, Faculty of Biology, Medicine and Health, University of Manchester, The Michael Smith Building, Oxford Road, Manchester, M13 9PT, UK
- Manchester Centre for Genomic Medicine, St. Mary's Hospital, Manchester Academic Health Sciences Centre (MAHSC), Manchester, M13 9WL, UK
| | - Uwe Kornak
- Berlin-Brandenburg Centre for Regenerative Therapies (BCRT), Institut fuer Medizinische Genetik und Humangenetik, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, Berlin, 13353, Germany
- FG Development & Disease, Max Planck Institut fuer Molekulare Genetik, Berlin, 14195, Germany
| | - Martin Lowe
- School of Biology, Faculty of Biology, Medicine and Health, University of Manchester, The Michael Smith Building, Oxford Road, Manchester, M13 9PT, UK.
| |
Collapse
|
113
|
Shahabi A, Naghili B, Ansarin K, Zarghami N. The relationship between microRNAs and Rab family GTPases in human cancers. J Cell Physiol 2019; 234:12341-12352. [PMID: 30609026 DOI: 10.1002/jcp.28038] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Accepted: 11/30/2018] [Indexed: 12/13/2022]
Abstract
microRNAs (miRNAs), as a group of noncoding RNAs, posttranscriptionally control gene expression by binding to 3'-untranslated region (3'-UTR). Ras-associated binding (Rab) proteins function as molecular switches for regulating vesicular transport, which mainly have oncogenic roles in cancer development and preventing the efficacy of chemotherapies. Increased evidence supported that miRNAs/Rabs interaction have been determined as potential therapeutics for cancer therapy. Nevertheless, instability and cross-targeting of miRNAs are main limitations of using miRNA-based therapeutic. The mutual interplay between Rabs and miRNAs has been poorly understood. In the present review, we focused on the essence and activity of these molecules in cancer pathogenesis. Also, numerous hindrances and potential methods in the expansion of miRNA as an anticancer therapeutics are mentioned.
Collapse
Affiliation(s)
- Arman Shahabi
- Infectious and Tropical Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.,Department of Molecular Medicine, Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz, Iran.,Student Research Committee, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Behrooz Naghili
- Infectious and Tropical Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Khalil Ansarin
- Tuberculosis and Lung Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Nosratollah Zarghami
- Infectious and Tropical Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.,Department of Molecular Medicine, Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz, Iran.,Department of Clinical Biochemistry and Laboratory Medicine, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| |
Collapse
|
114
|
Abstract
The Golgi apparatus is a central sorting station in the cell. It receives newly synthesized molecules from the endoplasmic reticulum and directs them to different subcellular destinations, such as the plasma membrane or the endocytic pathway. Importantly, in the last few years, it has emerged that the maintenance of Golgi structure is connected to the proper regulation of membrane trafficking. Rab proteins are small GTPases that are considered to be the master regulators of the intracellular membrane trafficking. Several of the over 60 human Rabs are involved in the regulation of transport pathways at the Golgi as well as in the maintenance of its architecture. This chapter will summarize the different roles of Rab GTPases at the Golgi, both as regulators of membrane transport, scaffold, and tethering proteins and in preserving the structure and function of this organelle.
Collapse
|
115
|
Prince E, Kroeger B, Gligorov D, Wilson C, Eaton S, Karch F, Brankatschk M, Maeda RK. Rab-mediated trafficking in the secondary cells of Drosophila male accessory glands and its role in fecundity. Traffic 2018; 20:137-151. [PMID: 30426623 PMCID: PMC6492190 DOI: 10.1111/tra.12622] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Revised: 11/01/2018] [Accepted: 11/06/2018] [Indexed: 12/16/2022]
Abstract
The male seminal fluid contains factors that affect female post‐mating behavior and physiology. In Drosophila, most of these factors are secreted by the two epithelial cell types that make up the male accessory gland: the main and secondary cells. Although secondary cells represent only ~4% of the cells of the accessory gland, their contribution to the male seminal fluid is essential for sustaining the female post‐mating response. To better understand the function of the secondary cells, we investigated their molecular organization, particularly with respect to the intracellular membrane transport machinery. We determined that large vacuole‐like structures found in the secondary cells are trafficking hubs labeled by Rab6, 7, 11 and 19. Furthermore, these organelles require Rab6 for their formation and many are essential in the process of creating the long‐term postmating behavior of females. In order to better serve the intracellular membrane and protein trafficking communities, we have created a searchable, online, open‐access imaging resource to display our complete findings regarding Rab localization in the accessory gland.
Collapse
Affiliation(s)
- Elodie Prince
- Department of Genetics and Evolution, Section of Biology, Sciences Faculty, University of Geneva, Geneva, Switzerland
| | - Benjamin Kroeger
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
| | - Dragan Gligorov
- Department of Genetics and Evolution, Section of Biology, Sciences Faculty, University of Geneva, Geneva, Switzerland
| | - Clive Wilson
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
| | - Suzanne Eaton
- Biotechnology Center of the TU Dresden, Dresden, Germany.,Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - François Karch
- Department of Genetics and Evolution, Section of Biology, Sciences Faculty, University of Geneva, Geneva, Switzerland
| | - Marko Brankatschk
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Robert K Maeda
- Department of Genetics and Evolution, Section of Biology, Sciences Faculty, University of Geneva, Geneva, Switzerland
| |
Collapse
|
116
|
Avci D, Malchus NS, Heidasch R, Lorenz H, Richter K, Neßling M, Lemberg MK. The intramembrane protease SPP impacts morphology of the endoplasmic reticulum by triggering degradation of morphogenic proteins. J Biol Chem 2018; 294:2786-2800. [PMID: 30578301 DOI: 10.1074/jbc.ra118.005642] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Revised: 12/12/2018] [Indexed: 11/06/2022] Open
Abstract
The endoplasmic reticulum (ER), as a multifunctional organelle, plays crucial roles in lipid biosynthesis and calcium homeostasis as well as the synthesis and folding of secretory and membrane proteins. Therefore, it is of high importance to maintain ER homeostasis and to adapt ER function and morphology to cellular needs. Here, we show that signal peptide peptidase (SPP) modulates the ER shape through degradation of morphogenic proteins. Elevating SPP activity induces rapid rearrangement of the ER and formation of dynamic ER clusters. Inhibition of SPP activity rescues the phenotype without the need for new protein synthesis, and this rescue depends on a pre-existing pool of proteins in the Golgi. With the help of organelle proteomics, we identified certain membrane proteins to be diminished upon SPP expression and further show that the observed morphology changes depend on SPP-mediated cleavage of ER morphogenic proteins, including the SNARE protein syntaxin-18. Thus, we suggest that SPP-mediated protein abundance control by a regulatory branch of ER-associated degradation (ERAD-R) has a role in shaping the early secretory pathway.
Collapse
Affiliation(s)
- Dönem Avci
- From the Centre for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, 69120 Heidelberg, Germany and
| | - Nicole S Malchus
- From the Centre for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, 69120 Heidelberg, Germany and
| | - Ronny Heidasch
- From the Centre for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, 69120 Heidelberg, Germany and
| | - Holger Lorenz
- From the Centre for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, 69120 Heidelberg, Germany and
| | - Karsten Richter
- German Cancer Research Center (DKFZ), Central Unit Electron Microscopy, 69120 Heidelberg, Germany
| | - Michelle Neßling
- German Cancer Research Center (DKFZ), Central Unit Electron Microscopy, 69120 Heidelberg, Germany
| | - Marius K Lemberg
- From the Centre for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, 69120 Heidelberg, Germany and
| |
Collapse
|
117
|
Abstract
Our understanding of fundamental biological processes within platelets is continually evolving. A critical feature of platelet biology relates to the intricate uptake, packaging and release of bioactive cargo from storage vesicles, essential in mediating a range of classical (haemostasis/thrombosis) and non-classical (regeneration/inflammation/metastasis) roles platelets assume. Pivotal to the molecular control of these vesicle trafficking events are the small GTPases of the Ras superfamily, which function as spatially distinct, molecular switches controlling essential cellular processes. Herein, we specifically focus on members of the Rab, Arf and Ras subfamilies, which comprise over 130 members and platelet proteomic datasets suggest that more than half of these are expressed in human platelets. We provide an update of current literature relating to trafficking roles for these GTPases in platelets, particularly regarding endocytic and exocytic events, but also vesicle biogenesis and provide speculative argument for roles that other related GTPases and regulatory proteins may adopt in platelets. Advances in our understanding of small GTPase function in the anucleate platelet has been hampered by the lack of specific molecular tools, but it is anticipated that this will be greatly accelerated in the years ahead and will be crucial to the identification of novel therapeutic targets controlling different platelet processes.
Collapse
Affiliation(s)
- Tony G Walsh
- a From the School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building , University of Bristol , Bristol , UK
| | - Yong Li
- a From the School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building , University of Bristol , Bristol , UK
| | - Andreas Wersäll
- a From the School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building , University of Bristol , Bristol , UK
| | - Alastair W Poole
- a From the School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building , University of Bristol , Bristol , UK
| |
Collapse
|
118
|
Nakajima K, Nozawa T, Minowa-Nozawa A, Toh H, Yamada S, Aikawa C, Nakagawa I. RAB30 regulates PI4KB (phosphatidylinositol 4-kinase beta)-dependent autophagy against group A Streptococcus. Autophagy 2018; 15:466-477. [PMID: 30290718 DOI: 10.1080/15548627.2018.1532260] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
Abstract
Macroautophagy/autophagy plays an important role in the immune response to invasion by intracellular pathogens such as group A Streptococcus (GAS; Streptococcus pyogenes). We previously identified RAB30, a Golgi-resident GTPase, as a novel anti-bacterial autophagic regulator in the formation of GAS-containing autophagosome-like vacuoles (GcAVs); however, the precise mechanism underlying this process remains elusive. Here, we elucidate a novel property of RAB30: the ability to recruit PI4KB (phosphatidylinositol 4-kinase beta) to the Golgi apparatus and GcAVs. We found that trans-Golgi network (TGN) vesicles were incorporated into GcAVs via RAB30 to promote GcAV formation. Moreover, depletion of phosphatidylinositol-4-phosphate (PtdIns4P), a phosphatidylinositol enriched in the TGN, by wortmannin and phenylarsine oxide, followed by subsequent repletion with exogenous PtdIns4P revealed that PtdIns4P is crucial for GcAV formation. Furthermore, we identify an interaction between RAB30 and PI4KB, in which the knockdown of RAB30 decreased the localization of PI4KB to the TGN and GcAVs. Finally, PI4KB knockout suppressed autophagy by inhibiting GcAV formation, resulting in the increased survival of GAS. Our results demonstrate a novel autophagosomal formation mechanism involving coordinative functions of RAB30 and PI4KB distinct from those utilized in canonical autophagy. Abbreviations: GAS: group A Streptococcus; GcAVs: GAS-containing autophagosome-like vacuoles; PI4KB: phosphatidylinositol 4-kinase beta; PtdIns: phosphatidylinositol; PtdIns3P: phosphatidylinositol-3-phosphate; PtdIns4P: phosphatidylinositol-4-phosphate; PtdIns5P: phosphatidylinositol-5-phosphate; SLO: streptolysin O; TGN: trans-Golgi network; TGOLN2: trans-golgi network protein 2; PH: plekstrin homology; OSBP: oxysterol binding protein.
Collapse
Affiliation(s)
- Koji Nakajima
- a Department of Microbiology, Graduate School of Medicine , Kyoto University , Kyoto , Japan
| | - Takashi Nozawa
- a Department of Microbiology, Graduate School of Medicine , Kyoto University , Kyoto , Japan
| | - Atsuko Minowa-Nozawa
- a Department of Microbiology, Graduate School of Medicine , Kyoto University , Kyoto , Japan
| | - Hirotaka Toh
- a Department of Microbiology, Graduate School of Medicine , Kyoto University , Kyoto , Japan
| | - Shunsuke Yamada
- a Department of Microbiology, Graduate School of Medicine , Kyoto University , Kyoto , Japan
| | - Chihiro Aikawa
- a Department of Microbiology, Graduate School of Medicine , Kyoto University , Kyoto , Japan
| | - Ichiro Nakagawa
- a Department of Microbiology, Graduate School of Medicine , Kyoto University , Kyoto , Japan
| |
Collapse
|
119
|
Nuclear immunoreactivity of BLM-s, a proapoptotic BCL-2 family member, is specifically detected in salivary adenoid cystic carcinoma. Hum Pathol 2018; 84:81-91. [PMID: 30261190 DOI: 10.1016/j.humpath.2018.09.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2018] [Revised: 09/12/2018] [Accepted: 09/14/2018] [Indexed: 11/24/2022]
Abstract
Tumor cells frequently evade apoptosis triggered by cellular stress via aberrant regulation of the BCL-2 family members, which are key players in regulating cell death under physiological and pathological situations. Previously, we have identified a novel BH3-only protein of the BCL-2 family, BLM-s (BCL-2-like molecule, short form), that modulates apoptosis of postmitotic immature neurons during corticohistogenesis. Whether BLM-s expression correlates with any subtype of human tumors has not been investigated. Here, via BLM-s immunohistochemistry performed in various kinds of human tumors, we demonstrate that BLM-s is specifically expressed in tumors derived from salivary gland (specificity, 0.76 [95% confidence interval, or CI], 0.65-0.85]; sensitivity, 1 [95% CI, 0.99-1]). Stratification of BLM-s immunointensity and its subcellular localization in correlation with salivary gland tumor subtype shows a statistically significant increase in proportion and in intensity of nuclear staining for adenoid cystic carcinoma (ACC; specificity, 0.92 [95% CI, 0.88-0.95]; sensitivity, 0.82 [95% CI, 0.66-0.92]), a locally aggressive head and neck malignancy. Comparison among salivary ACC in correlation with MYB/MYBL fluorescence in situ hybridization, c-KIT immunohistochemistry, and BLM-s immunohistochemistry shows that BLM-s' nuclear immunoreactivity has lower false-negative detection rate (18.5% compared with 26.3% [MYB/MYBL fluorescence in situ hybridization] and 34.2% [c-KIT], respectively). Intriguingly, ACC derived from other cell origins such as breast shows negative BLM-s immunoreactivity. We thus propose that nuclear localization of BLM-s detected by immunohistochemistry could be potentially used as an ancillary diagnostic marker for ACC originating from the salivary gland, especially when the biopsy specimen is small with an unknown tumor origin.
Collapse
|
120
|
Rosa-Ferreira C, Sweeney ST, Munro S. The small G protein Arl8 contributes to lysosomal function and long-range axonal transport in Drosophila. Biol Open 2018; 7:bio.035964. [PMID: 30115618 PMCID: PMC6176938 DOI: 10.1242/bio.035964] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The small GTPase Arl8 has emerged as a major regulatory GTPase on lysosomes. Studies in mammalian cells have shown that it regulates both fusion with late endosomes and also lysosomal motility. In its active GTP-bound state, it recruits to lysosomes the HOPS (homotypic fusion and protein sorting) endosomal tethering complex and also proteins that link lysosomes to microtubule motors such as the kinesin adaptor PLEKHM2. To gain further insights into Arl8 biology, we examined the single Drosophila ortholog. Drosophila Arl8 is essential for viability, and mitotic clones of mutant cells are able to continue to divide but show perturbation of the late endocytic pathway. Progeny-lacking Arl8 die as late larvae with movement-paralysis characteristic of defects in neuronal function. This phenotype was rescued by expression of Arl8 in motor neurons. Examination of these neurons in the mutant larvae revealed smaller synapses and axons with elevated levels of carriers containing synaptic components. Affinity chromatography revealed binding of Drosophila Arl8 to the HOPS complex, and to the Drosophila ortholog of RILP, a protein that, in mammals, recruits dynein to late endosomes, with dynein being known to be required for neuronal transport. Thus Drosophila Arl8 controls late endocytic function and transport via at least two distinct effectors. This article has an associated First Person interview with the first author of the paper. Summary:Drosophila Arl8 is essential for viability and is required for normal functioning of the late endocytic pathway and for long-range transport in axons.
Collapse
Affiliation(s)
| | - Sean T Sweeney
- Department of Biology, University of York, York, YO10 5DD, UK
| | - Sean Munro
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK
| |
Collapse
|
121
|
Rab GTPases in Osteoclastic Endomembrane Systems. BIOMED RESEARCH INTERNATIONAL 2018; 2018:4541538. [PMID: 30186859 PMCID: PMC6114073 DOI: 10.1155/2018/4541538] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/25/2018] [Accepted: 07/18/2018] [Indexed: 12/13/2022]
Abstract
Osteoclasts (OCs) are bone-resorbing cells that maintain bone homeostasis. OC differentiation, survival, and activity are regulated by numerous small GTPases, including those of the Rab family, which are involved in plasma membrane delivery and lysosomal and autophagic degradation pathways. In resorbing OCs, polarized vesicular trafficking pathways also result in formation of the ruffled membrane, the resorbing organelle, and in transcytosis.
Collapse
|
122
|
Lund VK, Madsen KL, Kjaerulff O. Drosophila Rab2 controls endosome-lysosome fusion and LAMP delivery to late endosomes. Autophagy 2018; 14:1520-1542. [PMID: 29940804 PMCID: PMC6135592 DOI: 10.1080/15548627.2018.1458170] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Rab2 is a conserved Rab GTPase with a well-established role in secretory pathway function and phagocytosis. Here we demonstrate that Drosophila Rab2 is recruited to late endosomal membranes, where it controls the fusion of LAMP-containing biosynthetic carriers and lysosomes to late endosomes. In contrast, the lysosomal GTPase Gie/Arl8 is only required for late endosome-lysosome fusion, but not for the delivery of LAMP to the endocytic pathway. We also find that Rab2 is required for the fusion of autophagosomes to the endolysosomal pathway, but not for the biogenesis of lysosome-related organelles. Surprisingly, Rab2 does not rely on HOPS-mediated vesicular fusion for recruitment to late endosomal membranes. Our work suggests that Drosophila Rab2 is a central regulator of the endolysosomal and macroautophagic/autophagic pathways by controlling the major heterotypic fusion processes at the late endosome.
Collapse
Affiliation(s)
- Viktor Karlovich Lund
- a Department of Neuroscience, The Faculty of Health Sciences , University of Copenhagen , Copenhagen , Denmark
| | - Kenneth Lindegaard Madsen
- a Department of Neuroscience, The Faculty of Health Sciences , University of Copenhagen , Copenhagen , Denmark
| | - Ole Kjaerulff
- a Department of Neuroscience, The Faculty of Health Sciences , University of Copenhagen , Copenhagen , Denmark
| |
Collapse
|
123
|
Langemeyer L, Fröhlich F, Ungermann C. Rab GTPase Function in Endosome and Lysosome Biogenesis. Trends Cell Biol 2018; 28:957-970. [PMID: 30025982 DOI: 10.1016/j.tcb.2018.06.007] [Citation(s) in RCA: 243] [Impact Index Per Article: 40.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 06/15/2018] [Accepted: 06/25/2018] [Indexed: 10/28/2022]
Abstract
Eukaryotic cells maintain a highly organized endolysosomal system. This system regulates the protein and lipid content of the plasma membrane, it participates in the intracellular quality control machinery and is needed for the efficient removal of damaged organelles. This complex network comprises an endosomal membrane system that feeds into the lysosomes, yet also allows recycling of membrane proteins, and probably lipids. Moreover, lysosomal degradation provides the cell with macromolecules for further growth. In this review, we focus primarily on the role of the small Rab GTPases Rab5 and Rab7 as organelle markers and interactors of multiple effectors on endosomes and lysosomes and highlight their role in membrane dynamics, particularly fusion along the endolysosomal pathway.
Collapse
Affiliation(s)
- Lars Langemeyer
- Department of Biology/Chemistry, Biochemistry Section, University of Osnabrück, Barbarastrasse 13, 49076 Osnabrück, Germany
| | - Florian Fröhlich
- Department of Biology/Chemistry, Molecular Membrane Biology Group, University of Osnabrück, Barbarastrasse 13, 49076 Osnabrück, Germany; Center of Cellular Nanoanalytics of the University of Osnabrück (CellNanOs), Barbarastrasse 11, 49076 Osnabrück, Germany
| | - Christian Ungermann
- Department of Biology/Chemistry, Biochemistry Section, University of Osnabrück, Barbarastrasse 13, 49076 Osnabrück, Germany; Department of Biology/Chemistry, Molecular Membrane Biology Group, University of Osnabrück, Barbarastrasse 13, 49076 Osnabrück, Germany; Center of Cellular Nanoanalytics of the University of Osnabrück (CellNanOs), Barbarastrasse 11, 49076 Osnabrück, Germany.
| |
Collapse
|
124
|
Bellec K, Gicquel I, Le Borgne R. Stratum recruits Rab8 at Golgi exit sites to regulate the basolateral sorting of Notch and Sanpodo. Development 2018; 145:145/13/dev163469. [PMID: 29967125 DOI: 10.1242/dev.163469] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Accepted: 05/21/2018] [Indexed: 01/03/2023]
Abstract
In Drosophila, the sensory organ precursor (SOP or pI cell) divides asymmetrically to give birth to daughter cells, the fates of which are governed by the differential activation of the Notch pathway. Proteolytic activation of Notch induced by ligand is based on the correct polarized sorting and localization of the Notch ligand Delta, the Notch receptor and its trafficking partner Sanpodo (Spdo). Here, we have identified Stratum (Strat), a presumptive guanine nucleotide exchange factor for Rab GTPases, as a regulator of Notch activation. Loss of Strat causes cell fate transformations associated with an accumulation of Notch, Delta and Spdo in the trans-Golgi network (TGN), and an apical accumulation of Spdo. The strat mutant phenotype is rescued by the catalytically active as well as the wild-type form of Rab8, suggesting a chaperone function for Strat rather than that of exchange factor. Strat is required to localize Rab8 at the TGN, and rab8 phenocopies strat We propose that Strat and Rab8 act at the exit of the Golgi apparatus to regulate the sorting and the polarized distribution of Notch, Delta and Spdo.
Collapse
Affiliation(s)
- Karen Bellec
- Univ Rennes, CNRS, IGDR (Institut de Génétique et Développement de Rennes) - UMR 6290, F-35000 Rennes, France
| | - Isabelle Gicquel
- Univ Rennes, CNRS, IGDR (Institut de Génétique et Développement de Rennes) - UMR 6290, F-35000 Rennes, France
| | - Roland Le Borgne
- Univ Rennes, CNRS, IGDR (Institut de Génétique et Développement de Rennes) - UMR 6290, F-35000 Rennes, France
| |
Collapse
|
125
|
Genetic dissection of neuropeptide cell biology at high and low activity in a defined sensory neuron. Proc Natl Acad Sci U S A 2018; 115:E6890-E6899. [PMID: 29959203 PMCID: PMC6055185 DOI: 10.1073/pnas.1714610115] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Neuropeptides are ubiquitous modulators of behavior and physiology. They are packaged in specialized secretory organelles called dense core vesicles (DCVs) that are released upon neural stimulation. Whereas local recycling of synaptic vesicles has been investigated intensively, there are few studies on recycling of DCV proteins. We set up a paradigm to study DCVs in a neuron whose activity we can control. We validate our model by confirming many previous observations on DCV cell biology. We identify a set of genes involved in recycling of DCV proteins. We also find evidence that different mechanisms of DCV priming and exocytosis may operate at high and low neural activity. Neuropeptides are ubiquitous modulators of behavior and physiology. They are packaged in specialized secretory organelles called dense core vesicles (DCVs) that are released upon neural stimulation. Unlike synaptic vesicles, which can be recycled and refilled close to release sites, DCVs must be replenished by de novo synthesis in the cell body. Here, we dissect DCV cell biology in vivo in a Caenorhabditis elegans sensory neuron whose tonic activity we can control using a natural stimulus. We express fluorescently tagged neuropeptides in the neuron and define parameters that describe their subcellular distribution. We measure these parameters at high and low neural activity in 187 mutants defective in proteins implicated in membrane traffic, neuroendocrine secretion, and neuronal or synaptic activity. Using unsupervised hierarchical clustering methods, we analyze these data and identify 62 groups of genes with similar mutant phenotypes. We explore the function of a subset of these groups. We recapitulate many previous findings, validating our paradigm. We uncover a large battery of proteins involved in recycling DCV membrane proteins, something hitherto poorly explored. We show that the unfolded protein response promotes DCV production, which may contribute to intertissue communication of stress. We also find evidence that different mechanisms of priming and exocytosis may operate at high and low neural activity. Our work provides a defined framework to study DCV biology at different neural activity levels.
Collapse
|
126
|
Jayson CBK, Arlt H, Fischer AW, Lai ZW, Farese RV, Walther TC. Rab18 is not necessary for lipid droplet biogenesis or turnover in human mammary carcinoma cells. Mol Biol Cell 2018; 29:2045-2054. [PMID: 29949452 PMCID: PMC6232964 DOI: 10.1091/mbc.e18-05-0282] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Rab GTPases recruit peripheral membrane proteins and can define organelle identity. Rab18 localizes to the endoplasmic reticulum (ER) but also to lipid droplets (LDs), where it has been implicated in effector protein recruitment and in defining LD identity. Here, we studied Rab18 localization and function in a human mammary carcinoma cell line. Rab18 localized to the ER and to LD membranes on LD induction, with the latter depending on the Rab18 activation state. In cells lacking Rab18, LDs were modestly reduced in size and numbers, but we found little evidence for Rab18 function in LD formation, LD turnover on cell starvation, or the targeting of several proteins to LDs. We conclude that Rab18 is not a general, necessary component of the protein machinery involved in LD biogenesis or turnover.
Collapse
Affiliation(s)
- Christina B K Jayson
- Department of Genetics and Complex Diseases, Harvard T. H. Chan School of Public Health, Boston, MA 02115.,Department of Cell Biology, Harvard Medical School, Boston, MA 02115
| | - Henning Arlt
- Department of Genetics and Complex Diseases, Harvard T. H. Chan School of Public Health, Boston, MA 02115.,Department of Cell Biology, Harvard Medical School, Boston, MA 02115
| | - Alexander W Fischer
- Department of Genetics and Complex Diseases, Harvard T. H. Chan School of Public Health, Boston, MA 02115.,Department of Cell Biology, Harvard Medical School, Boston, MA 02115.,Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, DE-20246 Hamburg, Germany
| | - Zon Weng Lai
- Department of Genetics and Complex Diseases, Harvard T. H. Chan School of Public Health, Boston, MA 02115.,Department of Cell Biology, Harvard Medical School, Boston, MA 02115
| | - Robert V Farese
- Department of Genetics and Complex Diseases, Harvard T. H. Chan School of Public Health, Boston, MA 02115.,Department of Cell Biology, Harvard Medical School, Boston, MA 02115.,Broad Institute of MIT and Harvard, Cambridge, MA 02142
| | - Tobias C Walther
- Department of Genetics and Complex Diseases, Harvard T. H. Chan School of Public Health, Boston, MA 02115.,Department of Cell Biology, Harvard Medical School, Boston, MA 02115.,Broad Institute of MIT and Harvard, Cambridge, MA 02142.,Howard Hughes Medical Institute, Boston, MA 02115
| |
Collapse
|
127
|
Identification of Host Factors Involved in Human Cytomegalovirus Replication, Assembly, and Egress Using a Two-Step Small Interfering RNA Screen. mBio 2018; 9:mBio.00716-18. [PMID: 29946045 PMCID: PMC6020295 DOI: 10.1128/mbio.00716-18] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
As obligate intracellular parasites, viruses are completely dependent on host factors for replication. Assembly and egress of complex virus particles, such as human cytomegalovirus (HCMV), are likely to require many host factors. Despite this, relatively few have been identified and characterized. This study describes a novel high-throughput, two-step small interfering RNA (siRNA) screen, which independently measures virus replication and virus production. By combining data from replication and virus production, multiple candidate genes were identified in which knockdown resulted in substantial loss of virus production with limited effect on primary replication, suggesting roles in later stages such as virus assembly and egress. Knockdown of the top candidates, ERC1, RAB4B, COPA, and COPB2, caused profound loss of virus production. Despite COPA and COPB2 being reported to function in the same complex, knockdown of these genes produced distinct phenotypes. Furthermore, knockdown of COPA caused increased expression of viral late genes despite substantial inhibition of viral DNA replication. This suggests that efficient viral genome replication is not required for late gene expression. Finally, we show that RAB4B relocates to the viral assembly compartment following infection with HCMV and knockdown of RAB4B reduces the release of intact virion particles, suggesting that it plays a role in virion assembly and egress. This study demonstrates a powerful high-throughput screen for identification of host-virus interactions, identifies multiple host genes associated with HCMV assembly and egress, and uncovers potentially independent functions for coatomer components COPA and COPB2 during infection. Human cytomegalovirus infection is a significant cause of disease in immunocompromised populations, individuals with heart disease, and recipients of solid organ and bone marrow transplants. HCMV is also the leading cause of infectious congenital birth defects. The majority of antivirals in clinical use target components of the virus to specifically inhibit replication. However, a major drawback of this approach is the emergence of resistance. An alternative approach is to target host factors that the virus requires for successful infection. In this study, multiple host factors were identified that were found to be essential for the production of newly infectious human cytomegalovirus. Identifying which host genes are necessary for virus replication extends our understanding of how viruses replicate and how cells function and provides potential targets for novel antivirals.
Collapse
|
128
|
Abstract
Fruit ripening is a complex developmental process that involves the synthesis and modification of the cell wall leading up to the formation of an edible fruit. During the period of fruit ripening, new cell wall polymers and enzymes are synthesized and trafficked to the apoplast. Vesicle trafficking has been shown to play a key role in facilitating the synthesis and modification of cell walls in fruits. Through reverse genetics and gene expression studies, the importance of Rab guanosine triphosphatases (GTPases) as integral regulators of vesicle trafficking to the cell wall has been revealed. It has been a decade since a rich literature on the involvement of Rab GTPase in ripening was published. Therefore, this review sets out to summarize the progress in studies on the pivotal roles of Rab GTPases in fruit development and sheds light on new approaches that could be adopted in the fields of postharvest biology and fruit-ripening research.
Collapse
Affiliation(s)
- Tamunonengiyeofori Lawson
- a School of Biosciences, Faculty of Science , The University of Nottingham, Malaysia Campus , Semenyih , Selangor , Malaysia.,b Division of Plant and Crop Sciences, School of Biosciences , University of Nottingham , Sutton Bonington Campus, Loughborough , Leicestershire , UK.,c Crops for the Future (CFF) , Semenyih , Malaysia
| | - Sean Mayes
- b Division of Plant and Crop Sciences, School of Biosciences , University of Nottingham , Sutton Bonington Campus, Loughborough , Leicestershire , UK.,c Crops for the Future (CFF) , Semenyih , Malaysia
| | - Grantley W Lycett
- b Division of Plant and Crop Sciences, School of Biosciences , University of Nottingham , Sutton Bonington Campus, Loughborough , Leicestershire , UK
| | - Chiew Foan Chin
- a School of Biosciences, Faculty of Science , The University of Nottingham, Malaysia Campus , Semenyih , Selangor , Malaysia
| |
Collapse
|
129
|
Abstract
Cytoplasmic dynein 1 is an important microtubule-based motor in many eukaryotic cells. Dynein has critical roles both in interphase and during cell division. Here, we focus on interphase cargoes of dynein, which include membrane-bound organelles, RNAs, protein complexes and viruses. A central challenge in the field is to understand how a single motor can transport such a diverse array of cargoes and how this process is regulated. The molecular basis by which each cargo is linked to dynein and its cofactor dynactin has started to emerge. Of particular importance for this process is a set of coiled-coil proteins - activating adaptors - that both recruit dynein-dynactin to their cargoes and activate dynein motility.
Collapse
|
130
|
Pylypenko O, Hammich H, Yu IM, Houdusse A. Rab GTPases and their interacting protein partners: Structural insights into Rab functional diversity. Small GTPases 2018. [PMID: 28632484 DOI: 10.1080/215412481336191] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/23/2023] Open
Abstract
Rab molecular switches are key players in defining membrane identity and regulating intracellular trafficking events in eukaryotic cells. In spite of their global structural similarity, Rab-family members acquired particular features that allow them to perform specific cellular functions. The overall fold and local sequence conservations enable them to utilize a common machinery for prenylation and recycling; while individual Rab structural differences determine interactions with specific partners such as GEFs, GAPs and effector proteins. These interactions orchestrate the spatiotemporal regulation of Rab localization and their turning ON and OFF, leading to tightly controlled Rab-specific functionalities such as membrane composition modifications, recruitment of molecular motors for intracellular trafficking, or recruitment of scaffold proteins that mediate interactions with downstream partners, as well as actin cytoskeleton regulation. In this review we summarize structural information on Rab GTPases and their complexes with protein partners in the context of partner binding specificity and functional outcomes of their interactions in the cell.
Collapse
Affiliation(s)
- Olena Pylypenko
- a Structural Motility, Institut Curie , PSL Research University, CNRS, UMR 144 , Paris , France
| | - Hussein Hammich
- a Structural Motility, Institut Curie , PSL Research University, CNRS, UMR 144 , Paris , France
- b Sorbonne Universités , UPMC Univ Paris 06, Sorbonne Universités, IFD , Paris , France
| | - I-Mei Yu
- a Structural Motility, Institut Curie , PSL Research University, CNRS, UMR 144 , Paris , France
| | - Anne Houdusse
- a Structural Motility, Institut Curie , PSL Research University, CNRS, UMR 144 , Paris , France
| |
Collapse
|
131
|
Banworth MJ, Li G. Consequences of Rab GTPase dysfunction in genetic or acquired human diseases. Small GTPases 2018. [PMID: 29239692 DOI: 10.1080/215412481397833] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/23/2023] Open
Abstract
Rab GTPases are important regulators of intracellular membrane trafficking in eukaryotes. Both activating and inactivating mutations in Rab genes have been identified and implicated in human diseases ranging from neurological disorders to cancer. In addition, altered Rab expression is often associated with disease prognosis. As such, the study of diseases associated with Rabs or Rab-interacting proteins has shed light on the important role of intracellular membrane trafficking in disease etiology. In this review, we cover recent advances in the field with an emphasis on cellular mechanisms.
Collapse
Affiliation(s)
- Marcellus J Banworth
- a Department of Biochemistry and Molecular Biology , University of Oklahoma Health Sciences Center , Oklahoma City , OK , USA
| | - Guangpu Li
- a Department of Biochemistry and Molecular Biology , University of Oklahoma Health Sciences Center , Oklahoma City , OK , USA
| |
Collapse
|
132
|
Xu D, Li Y, Wu L, Li Y, Zhao D, Yu J, Huang T, Ferguson C, Parton RG, Yang H, Li P. Rab18 promotes lipid droplet (LD) growth by tethering the ER to LDs through SNARE and NRZ interactions. J Cell Biol 2018; 217:975-995. [PMID: 29367353 PMCID: PMC5839781 DOI: 10.1083/jcb.201704184] [Citation(s) in RCA: 148] [Impact Index Per Article: 24.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2017] [Revised: 10/12/2017] [Accepted: 12/22/2017] [Indexed: 12/16/2022] Open
Abstract
Lipid incorporation from endoplasmic reticulum (ER) to lipid droplet (LD) is important in controlling LD growth and intracellular lipid homeostasis. However, the molecular link mediating ER and LD cross talk remains elusive. Here, we identified Rab18 as an important Rab guanosine triphosphatase in controlling LD growth and maturation. Rab18 deficiency resulted in a drastically reduced number of mature LDs and decreased lipid storage, and was accompanied by increased ER stress. Rab3GAP1/2, the GEF of Rab18, promoted LD growth by activating and targeting Rab18 to LDs. LD-associated Rab18 bound specifically to the ER-associated NAG-RINT1-ZW10 (NRZ) tethering complex and their associated SNAREs (Syntaxin18, Use1, BNIP1), resulting in the recruitment of ER to LD and the formation of direct ER-LD contact. Cells with defects in the NRZ/SNARE complex function showed reduced LD growth and lipid storage. Overall, our data reveal that the Rab18-NRZ-SNARE complex is critical protein machinery for tethering ER-LD and establishing ER-LD contact to promote LD growth.
Collapse
Affiliation(s)
- Dijin Xu
- State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China
| | - Yuqi Li
- State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China
| | - Lizhen Wu
- State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China
| | - Ying Li
- State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China
| | - Dongyu Zhao
- State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China
| | - Jinhai Yu
- State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China
| | - Tuozhi Huang
- State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China
| | - Charles Ferguson
- Institute for Molecular Bioscience, University of Queensland, Brisbane, Australia
| | - Robert G Parton
- Institute for Molecular Bioscience, University of Queensland, Brisbane, Australia.,Centre for Microscopy and Microanalysis, University of Queensland, Brisbane, Australia
| | - Hongyuan Yang
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, Australia
| | - Peng Li
- State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China
| |
Collapse
|
133
|
Zhang C, Ding W, Liu Y, Hu Z, Zhu D, Wang X, Yu L, Wang L, Shen H, Zhang W, Ren C, Li K, Weng D, Deng W, Ma D, Wang H. Proteomics-based identification of VDAC1 as a tumor promoter in cervical carcinoma. Oncotarget 2018; 7:52317-52328. [PMID: 27419626 PMCID: PMC5239554 DOI: 10.18632/oncotarget.10562] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Accepted: 06/12/2016] [Indexed: 02/05/2023] Open
Abstract
We used oxidative isotope-coded affinity tags (OxICAT) to investigate the global redox status of proteins in human papillomavirus (HPV)-related cervical cancer cells, in order to identify a potential target for gene therapy. Voltage-dependent anion channel 1 (VDAC1) was found to be highly oxidized in HPV-positive cervical cancer cells. VDAC1 expression correlated significantly with the invasion of cervical cancer, the grade of cervical intraepithelial neoplasia (CIN) and the expression of HPV16 E7 in CIN. Knockdown of VDAC1 in cell lines increased the rate of apoptosis, while overexpression of the VDAC1 (respectively) partly reversed the effect. Thus, VDAC1 may promote the malignant progression of HPV-related disease, and treatments designed to suppress VDAC1 could prevent the progression of HPV-induced cervical disease.
Collapse
Affiliation(s)
- Changlin Zhang
- Department of Obstetrics and Gynecology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China.,Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center of Cancer Medicine, Guangzhou, Guangdong 510060, China
| | - Wencheng Ding
- Department of Obstetrics and Gynecology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China
| | - Yuan Liu
- The State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Sichuan 610041, China
| | - Zheng Hu
- Department of Obstetrics and Gynecology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China
| | - Da Zhu
- Department of Obstetrics and Gynecology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China
| | - Xiaoli Wang
- Department of Obstetrics and Gynecology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China
| | - Lan Yu
- Department of Obstetrics and Gynecology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China
| | - Liming Wang
- Department of Obstetrics and Gynecology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China
| | - Hui Shen
- Department of Obstetrics and Gynecology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China
| | - Weican Zhang
- Department of Obstetrics and Gynecology, Hebei Medical University, Shijiazhuang, Hebei 050017, China
| | - Ci Ren
- Department of Obstetrics and Gynecology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China
| | - Kezhen Li
- Department of Obstetrics and Gynecology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China
| | - Danhui Weng
- Department of Obstetrics and Gynecology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China
| | - Wuguo Deng
- Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center of Cancer Medicine, Guangzhou, Guangdong 510060, China
| | - Ding Ma
- Department of Obstetrics and Gynecology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China
| | - Hui Wang
- Department of Obstetrics and Gynecology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China
| |
Collapse
|
134
|
Banworth MJ, Li G. Consequences of Rab GTPase dysfunction in genetic or acquired human diseases. Small GTPases 2017; 9:158-181. [PMID: 29239692 DOI: 10.1080/21541248.2017.1397833] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Rab GTPases are important regulators of intracellular membrane trafficking in eukaryotes. Both activating and inactivating mutations in Rab genes have been identified and implicated in human diseases ranging from neurological disorders to cancer. In addition, altered Rab expression is often associated with disease prognosis. As such, the study of diseases associated with Rabs or Rab-interacting proteins has shed light on the important role of intracellular membrane trafficking in disease etiology. In this review, we cover recent advances in the field with an emphasis on cellular mechanisms.
Collapse
Affiliation(s)
- Marcellus J Banworth
- a Department of Biochemistry and Molecular Biology , University of Oklahoma Health Sciences Center , Oklahoma City , OK , USA
| | - Guangpu Li
- a Department of Biochemistry and Molecular Biology , University of Oklahoma Health Sciences Center , Oklahoma City , OK , USA
| |
Collapse
|
135
|
At the ends of their tethers! How coiled-coil proteins capture vesicles at the Golgi. Biochem Soc Trans 2017; 46:43-50. [PMID: 29273618 DOI: 10.1042/bst20170188] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Revised: 11/22/2017] [Accepted: 11/23/2017] [Indexed: 12/20/2022]
Abstract
Cells face a complex problem: how to transfer lipids and proteins between membrane compartments in an organized, timely fashion. Indeed, many thousands of membrane and secretory proteins must traffic out of the ER to different organelles to function, while others are retrieved from the plasma membrane having fulfilled their roles [Nat. Rev. Mol. Cell Biol. (2013) 14, 382-392]. This process is highly dynamic and failure to target cargo accurately leads to catastrophic consequences for the cell, as is clear from the numerous human diseases associated with defects in membrane trafficking [Int. J. Mol. Sci. (2013) 14, 18670-18681; Traffic (2000) 1, 836-851]. How then does the cell organize this enormous transfer of material in its crowded internal environment? And how specifically do vesicles carrying proteins and lipids recognize and fuse with the correct compartment?
Collapse
|
136
|
Riedel F, Galindo A, Muschalik N, Munro S. The two TRAPP complexes of metazoans have distinct roles and act on different Rab GTPases. J Cell Biol 2017; 217:601-617. [PMID: 29273580 PMCID: PMC5800803 DOI: 10.1083/jcb.201705068] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Revised: 10/19/2017] [Accepted: 11/27/2017] [Indexed: 12/03/2022] Open
Abstract
In yeast, the TRAPP complexes activate Rab1 with TRAPPII also activating Rab11, but less is known about the two TRAPPs in metazoans. Riedel et al. show that in Drosophila melanogaster, TRAPPIII is an essential Rab1 activator, and TRAPPII activates Rab1 and Rab11 and becomes essential when an unrelated Rab11 activator is deleted. Originally identified in yeast, transport protein particle (TRAPP) complexes are Rab GTPase exchange factors that share a core set of subunits. TRAPPs were initially found to act on Ypt1, the yeast orthologue of Rab1, but recent studies have found that yeast TRAPPII can also activate the Rab11 orthologues Ypt31/32. Mammals have two TRAPP complexes, but their role is less clear, and they contain subunits that are not found in the yeast complexes but are essential for cell growth. To investigate TRAPP function in metazoans, we show that Drosophila melanogaster have two TRAPP complexes similar to those in mammals and that both activate Rab1, whereas one, TRAPPII, also activates Rab11. TRAPPII is not essential but becomes so in the absence of the gene parcas that encodes the Drosophila orthologue of the SH3BP5 family of Rab11 guanine nucleotide exchange factors (GEFs). Thus, in metazoans, Rab1 activation requires TRAPP subunits not found in yeast, and Rab11 activation is shared by TRAPPII and an unrelated GEF that is metazoan specific.
Collapse
Affiliation(s)
- Falko Riedel
- Medical Research Council Laboratory of Molecular Biology, Cambridge, England, UK
| | - Antonio Galindo
- Medical Research Council Laboratory of Molecular Biology, Cambridge, England, UK
| | - Nadine Muschalik
- Medical Research Council Laboratory of Molecular Biology, Cambridge, England, UK
| | - Sean Munro
- Medical Research Council Laboratory of Molecular Biology, Cambridge, England, UK
| |
Collapse
|
137
|
Kaczmarek B, Verbavatz JM, Jackson CL. GBF1 and Arf1 function in vesicular trafficking, lipid homoeostasis and organelle dynamics. Biol Cell 2017; 109:391-399. [PMID: 28985001 DOI: 10.1111/boc.201700042] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Revised: 09/22/2017] [Accepted: 09/25/2017] [Indexed: 01/07/2023]
Abstract
The ADP-ribosylation factor (Arf) small G proteins act as molecular switches to coordinate multiple downstream pathways that regulate membrane dynamics. Their activation is spatially and temporally controlled by the guanine nucleotide exchange factors (GEFs). Members of the evolutionarily conserved GBF/Gea family of Arf GEFs are well known for their roles in formation of coat protein complex I (COPI) vesicles, essential for maintaining the structure and function of the Golgi apparatus. However, studies over the past 10 years have found new functions for these GEFs, along with their substrate Arf1, in lipid droplet metabolism, clathrin-independent endocytosis, signalling at the plasma membrane, mitochondrial dynamics and transport along microtubules. Here, we describe these different functions, focussing in particular on the emerging theme of GFB1 and Arf1 regulation of organelle movement on microtubules.
Collapse
Affiliation(s)
- Beata Kaczmarek
- Institut Jacques Monod, CNRS, UMR 7592, Université Paris Diderot, Paris, F-75013, France
| | - Jean-Marc Verbavatz
- Institut Jacques Monod, CNRS, UMR 7592, Université Paris Diderot, Paris, F-75013, France
| | - Catherine L Jackson
- Institut Jacques Monod, CNRS, UMR 7592, Université Paris Diderot, Paris, F-75013, France
| |
Collapse
|
138
|
Nagy P, Szatmári Z, Sándor GO, Lippai M, Hegedűs K, Juhász G. Drosophila Atg16 promotes enteroendocrine cell differentiation via regulation of intestinal Slit/Robo signaling. Development 2017; 144:3990-4001. [PMID: 28982685 DOI: 10.1242/dev.147033] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Accepted: 09/25/2017] [Indexed: 12/22/2022]
Abstract
Genetic variations of Atg16l1, Slit2 and Rab19 predispose to the development of inflammatory bowel disease (IBD), but the relationship between these mutations is unclear. Here we show that in Drosophila guts lacking the WD40 domain of Atg16, pre-enteroendocrine (pre-EE) cells accumulate that fail to differentiate into properly functioning secretory EE cells. Mechanistically, loss of Atg16 or its binding partner Rab19 impairs Slit production, which normally inhibits EE cell generation by activating Robo signaling in stem cells. Importantly, loss of Atg16 or decreased Slit/Robo signaling triggers an intestinal inflammatory response. Surprisingly, analysis of Rab19 and domain-specific Atg16 mutants indicates that their stem cell niche regulatory function is independent of autophagy. Our study reveals how mutations in these different genes may contribute to IBD.
Collapse
Affiliation(s)
- Péter Nagy
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Pázmány s. 1/C, Budapest, H-1117 Hungary
| | - Zsuzsanna Szatmári
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Pázmány s. 1/C, Budapest, H-1117 Hungary
| | - Gyöngyvér O Sándor
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Pázmány s. 1/C, Budapest, H-1117 Hungary
| | - Mónika Lippai
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Pázmány s. 1/C, Budapest, H-1117 Hungary
| | - Krisztina Hegedűs
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Pázmány s. 1/C, Budapest, H-1117 Hungary
| | - Gábor Juhász
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Pázmány s. 1/C, Budapest, H-1117 Hungary
- Institute of Genetics, Biological Research Centre, Hungarian Academy of Sciences, Temesvári krt. 62, Szeged, H-6726 Hungary
| |
Collapse
|
139
|
Csizmadia T, Lőrincz P, Hegedűs K, Széplaki S, Lőw P, Juhász G. Molecular mechanisms of developmentally programmed crinophagy in Drosophila. J Cell Biol 2017; 217:361-374. [PMID: 29066608 PMCID: PMC5748974 DOI: 10.1083/jcb.201702145] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Revised: 08/09/2017] [Accepted: 09/22/2017] [Indexed: 12/20/2022] Open
Abstract
During crinophagy, secretory granules directly fuse with lysosomes to degrade their contents. Csizmadia et al. show that excess glue granules in Drosophila salivary glands are degraded by crinophagy at the onset of metamorphosis. Glue granule–lysosome fusion requires the HOPS tether, Rab2, Rab7, and a SNARE complex consisting of Syntaxin 13, Snap29, and Vamp7. At the onset of metamorphosis, Drosophila salivary gland cells undergo a burst of glue granule secretion to attach the forming pupa to a solid surface. Here, we show that excess granules evading exocytosis are degraded via direct fusion with lysosomes, a secretory granule-specific autophagic process known as crinophagy. We find that the tethering complex HOPS (homotypic fusion and protein sorting); the small GTPases Rab2, Rab7, and its effector, PLEKHM1; and a SNAP receptor complex consisting of Syntaxin 13, Snap29, and Vamp7 are all required for the fusion of secretory granules with lysosomes. Proper glue degradation within lysosomes also requires the Uvrag-containing Vps34 lipid kinase complex and the v-ATPase proton pump, whereas Atg genes involved in macroautophagy are dispensable for crinophagy. Our work establishes the molecular mechanism of developmentally programmed crinophagy in Drosophila and paves the way for analyzing this process in metazoans.
Collapse
Affiliation(s)
- Tamás Csizmadia
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest, Hungary
| | - Péter Lőrincz
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest, Hungary
| | - Krisztina Hegedűs
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest, Hungary
| | - Szilvia Széplaki
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest, Hungary
| | - Péter Lőw
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest, Hungary
| | - Gábor Juhász
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest, Hungary .,Institute of Genetics, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| |
Collapse
|
140
|
Cattin-Ortolá J, Topalidou I, Dosey A, Merz AJ, Ailion M. The dense-core vesicle maturation protein CCCP-1 binds RAB-2 and membranes through its C-terminal domain. Traffic 2017; 18:720-732. [PMID: 28755404 DOI: 10.1111/tra.12507] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2017] [Revised: 07/26/2017] [Accepted: 07/26/2017] [Indexed: 12/18/2022]
Abstract
Dense-core vesicles (DCVs) are secretory organelles that store and release modulatory neurotransmitters from neurons and endocrine cells. Recently, the conserved coiled-coil protein CCCP-1 was identified as a component of the DCV biogenesis pathway in the nematode Caenorhabditis elegans. CCCP-1 binds the small GTPase RAB-2 and colocalizes with it at the trans-Golgi. Here, we report a structure-function analysis of CCCP-1 to identify domains of the protein important for its localization, binding to RAB-2, and function in DCV biogenesis. We find that the CCCP-1 C-terminal domain (CC3) has multiple activities. CC3 is necessary and sufficient for CCCP-1 localization and for binding to RAB-2, and is required for the function of CCCP-1 in DCV biogenesis. In addition, CCCP-1 binds membranes directly through its CC3 domain, indicating that CC3 may comprise a previously uncharacterized lipid-binding motif. We conclude that CCCP-1 is a coiled-coil protein that binds an activated Rab and localizes to the Golgi via its C-terminus, properties similar to members of the golgin family of proteins. CCCP-1 also shares biophysical features with golgins; it has an elongated shape and forms oligomers.
Collapse
Affiliation(s)
| | - Irini Topalidou
- Department of Biochemistry, University of Washington, Seattle, Washington
| | - Annie Dosey
- Department of Biochemistry, University of Washington, Seattle, Washington
| | - Alexey J Merz
- Department of Biochemistry, University of Washington, Seattle, Washington.,Department of Physiology and Biophysics, University of Washington, Seattle, Washington
| | - Michael Ailion
- Department of Biochemistry, University of Washington, Seattle, Washington
| |
Collapse
|
141
|
Identification of Rab18 as an Essential Host Factor for BK Polyomavirus Infection Using a Whole-Genome RNA Interference Screen. mSphere 2017; 2:mSphere00291-17. [PMID: 28815213 PMCID: PMC5555678 DOI: 10.1128/mspheredirect.00291-17] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2017] [Accepted: 07/12/2017] [Indexed: 11/20/2022] Open
Abstract
Polyomaviruses bind to a group of specific gangliosides on the plasma membrane of the cell prior to being endocytosed. They then follow a retrograde trafficking pathway to reach the endoplasmic reticulum (ER). The viruses begin to disassemble in the ER and then exit the ER and move to the nucleus. However, the details of intracellular trafficking between the endosome and the ER are largely unknown. By implementing a whole human genome small interfering RNA screen, we identified Rab18, syntaxin 18, and the NRZ complex as key components in endosome-ER trafficking of the human polyomavirus BKPyV. These results serve to further elucidate the route BKPyV takes from outside the cell to its site of replication in the nucleus. BK polyomavirus (BKPyV) is a human pathogen first isolated in 1971. BKPyV infection is ubiquitous in the human population, with over 80% of adults worldwide being seropositive for BKPyV. BKPyV infection is usually asymptomatic; however, BKPyV reactivation in immunosuppressed transplant patients causes two diseases, polyomavirus-associated nephropathy and hemorrhagic cystitis. To establish a successful infection in host cells, BKPyV must travel in retrograde transport vesicles to reach the nucleus. To make this happen, BKPyV requires the cooperation of host cell proteins. To further identify host factors associated with BKPyV entry and intracellular trafficking, we performed a whole-genome small interfering RNA screen on BKPyV infection of primary human renal proximal tubule epithelial cells. The results revealed the importance of Ras-related protein Rab18 and syntaxin 18 for BKPyV infection. Our subsequent experiments implicated additional factors that interact with this pathway and suggest a more detailed model of the intracellular trafficking process, indicating that BKPyV reaches the endoplasmic reticulum (ER) lumen through a retrograde transport pathway between the late endosome and the ER. IMPORTANCE Polyomaviruses bind to a group of specific gangliosides on the plasma membrane of the cell prior to being endocytosed. They then follow a retrograde trafficking pathway to reach the endoplasmic reticulum (ER). The viruses begin to disassemble in the ER and then exit the ER and move to the nucleus. However, the details of intracellular trafficking between the endosome and the ER are largely unknown. By implementing a whole human genome small interfering RNA screen, we identified Rab18, syntaxin 18, and the NRZ complex as key components in endosome-ER trafficking of the human polyomavirus BKPyV. These results serve to further elucidate the route BKPyV takes from outside the cell to its site of replication in the nucleus.
Collapse
|
142
|
Pylypenko O, Hammich H, Yu IM, Houdusse A. Rab GTPases and their interacting protein partners: Structural insights into Rab functional diversity. Small GTPases 2017. [PMID: 28632484 PMCID: PMC5902227 DOI: 10.1080/21541248.2017.1336191] [Citation(s) in RCA: 89] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Rab molecular switches are key players in defining membrane identity and regulating intracellular trafficking events in eukaryotic cells. In spite of their global structural similarity, Rab-family members acquired particular features that allow them to perform specific cellular functions. The overall fold and local sequence conservations enable them to utilize a common machinery for prenylation and recycling; while individual Rab structural differences determine interactions with specific partners such as GEFs, GAPs and effector proteins. These interactions orchestrate the spatiotemporal regulation of Rab localization and their turning ON and OFF, leading to tightly controlled Rab-specific functionalities such as membrane composition modifications, recruitment of molecular motors for intracellular trafficking, or recruitment of scaffold proteins that mediate interactions with downstream partners, as well as actin cytoskeleton regulation. In this review we summarize structural information on Rab GTPases and their complexes with protein partners in the context of partner binding specificity and functional outcomes of their interactions in the cell.
Collapse
Affiliation(s)
- Olena Pylypenko
- a Structural Motility, Institut Curie , PSL Research University, CNRS, UMR 144 , Paris , France
| | - Hussein Hammich
- a Structural Motility, Institut Curie , PSL Research University, CNRS, UMR 144 , Paris , France.,b Sorbonne Universités , UPMC Univ Paris 06, Sorbonne Universités, IFD , Paris , France
| | - I-Mei Yu
- a Structural Motility, Institut Curie , PSL Research University, CNRS, UMR 144 , Paris , France
| | - Anne Houdusse
- a Structural Motility, Institut Curie , PSL Research University, CNRS, UMR 144 , Paris , France
| |
Collapse
|
143
|
Golgi trafficking defects in postnatal microcephaly: The evidence for “Golgipathies”. Prog Neurobiol 2017; 153:46-63. [DOI: 10.1016/j.pneurobio.2017.03.007] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Revised: 02/22/2017] [Accepted: 03/29/2017] [Indexed: 12/17/2022]
|
144
|
Thomason PA, King JS, Insall RH. Mroh1, a lysosomal regulator localized by WASH-generated actin. J Cell Sci 2017; 130:1785-1795. [PMID: 28424231 PMCID: PMC5450189 DOI: 10.1242/jcs.197210] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Accepted: 03/29/2017] [Indexed: 02/06/2023] Open
Abstract
The steps leading to constitutive exocytosis are poorly understood. In Dictyostelium WASH complex mutants, exocytosis is blocked, so cells that take up fluorescent dextran from the medium retain it and remain fluorescent. Here, we establish a FACS-based method to select cells that retain fluorescent dextran, allowing identification of mutants with disrupted exocytosis. Screening a pool of random mutants identified members of the WASH complex, as expected, and multiple mutants in the conserved HEAT-repeat-containing protein Mroh1. In mroh1 mutants, endosomes develop normally until the stage where lysosomes neutralize to postlysosomes, but thereafter the WASH complex is recycled inefficiently, and subsequent exocytosis is substantially delayed. Mroh1 protein localizes to lysosomes in mammalian and Dictyostelium cells. In Dictyostelium, it accumulates on lysosomes as they mature and is removed, together with the WASH complex, shortly before the postlysosomes are exocytosed. WASH-generated F-actin is required for correct subcellular localization; in WASH complex mutants, and immediately after latrunculin treatment, Mroh1 relocalizes from the cytoplasm to small vesicles. Thus, Mroh1 is involved in a late and hitherto undefined actin-dependent step in exocytosis.
Collapse
Affiliation(s)
- Peter A Thomason
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK
| | - Jason S King
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK
| | - Robert H Insall
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK
| |
Collapse
|
145
|
Lőrincz P, Tóth S, Benkő P, Lakatos Z, Boda A, Glatz G, Zobel M, Bisi S, Hegedűs K, Takáts S, Scita G, Juhász G. Rab2 promotes autophagic and endocytic lysosomal degradation. J Cell Biol 2017; 216:1937-1947. [PMID: 28483915 PMCID: PMC5496615 DOI: 10.1083/jcb.201611027] [Citation(s) in RCA: 92] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2016] [Revised: 02/24/2017] [Accepted: 04/21/2017] [Indexed: 11/22/2022] Open
Abstract
Rab7 promotes fusion of autophagosomes and late endosomes with lysosomes. Lőrincz et al. show that Rab2 is critical for the delivery of autophagic and endocytic cargo to lysosomes and for their degradation, and that it promotes autophagosome–lysosome fusion. The results suggest Rab2 and Rab7 coordinately promote autophagic and endosomal degradation and lysosome function. Rab7 promotes fusion of autophagosomes and late endosomes with lysosomes in yeast and metazoan cells, acting together with its effector, the tethering complex HOPS. Here we show that another small GTPase, Rab2, is also required for autophagosome and endosome maturation and proper lysosome function in Drosophila melanogaster. We demonstrate that Rab2 binds to HOPS, and that its active, GTP-locked form associates with autolysosomes. Importantly, expression of active Rab2 promotes autolysosomal fusions unlike that of GTP-locked Rab7, suggesting that its amount is normally rate limiting. We also demonstrate that RAB2A is required for autophagosome clearance in human breast cancer cells. In conclusion, we identify Rab2 as a key factor for autophagic and endocytic cargo delivery to and degradation in lysosomes.
Collapse
Affiliation(s)
- Péter Lőrincz
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest H-1117, Hungary
| | - Sarolta Tóth
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest H-1117, Hungary
| | - Péter Benkő
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest H-1117, Hungary
| | - Zsolt Lakatos
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest H-1117, Hungary
| | - Attila Boda
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest H-1117, Hungary
| | - Gábor Glatz
- Institute of Genetics, Biological Research Centre, Hungarian Academy of Sciences, Szeged H-6726, Hungary
| | - Martina Zobel
- FIRC (Fondazione Italiana per la Ricerca sul Cancro) Institute of Molecular Oncology (IFOM), Milan 20139, Italy
| | - Sara Bisi
- FIRC (Fondazione Italiana per la Ricerca sul Cancro) Institute of Molecular Oncology (IFOM), Milan 20139, Italy
| | - Krisztina Hegedűs
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest H-1117, Hungary
| | - Szabolcs Takáts
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest H-1117, Hungary
| | - Giorgio Scita
- FIRC (Fondazione Italiana per la Ricerca sul Cancro) Institute of Molecular Oncology (IFOM), Milan 20139, Italy.,Department of Oncology and Hemato-Oncology, School of Medicine, University of Milan, Milan 20122, Italy
| | - Gábor Juhász
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest H-1117, Hungary .,Institute of Genetics, Biological Research Centre, Hungarian Academy of Sciences, Szeged H-6726, Hungary
| |
Collapse
|
146
|
Abstract
ADP-ribosylation factors (Arfs) and ADP-ribosylation factor-like proteins (Arls) are highly conserved small GTPases that function as main regulators of vesicular trafficking and cytoskeletal reorganization. Arl1, the first identified member of the large Arl family, is an important regulator of Golgi complex structure and function in organisms ranging from yeast to mammals. Together with its effectors, Arl1 has been shown to be involved in several cellular processes, including endosomal trans-Golgi network and secretory trafficking, lipid droplet and salivary granule formation, innate immunity and neuronal development, stress tolerance, as well as the response of the unfolded protein. In this Commentary, we provide a comprehensive summary of the Arl1-dependent cellular functions and a detailed characterization of several Arl1 effectors. We propose that involvement of Arl1 in these diverse cellular functions reflects the fact that Arl1 is activated at several late-Golgi sites, corresponding to specific molecular complexes that respond to and integrate multiple signals. We also provide insight into how the GTP-GDP cycle of Arl1 is regulated, and highlight a newly discovered mechanism that controls the sophisticated regulation of Arl1 activity at the Golgi complex.
Collapse
Affiliation(s)
- Chia-Jung Yu
- Department of Cell and Molecular Biology, College of Medicine, Chang Gung University, Linkou, Tao-Yuan 33302, Taiwan.,Department of Thoracic Medicine, Chang Gung Memorial Hospital, Linkou, Tao-Yuan 33305, Taiwan
| | - Fang-Jen S Lee
- Institute of Molecular Medicine, College of Medicine, National Taiwan University, Taipei 10002, Taiwan .,Department of Medical Research, National Taiwan University Hospital, Taipei 10002, Taiwan
| |
Collapse
|
147
|
Mallik B, Dwivedi MK, Mushtaq Z, Kumari M, Verma PK, Kumar V. Regulation of neuromuscular junction organization by Rab2 and its effector ICA69 in Drosophila. Development 2017; 144:2032-2044. [PMID: 28455372 DOI: 10.1242/dev.145920] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Accepted: 04/19/2017] [Indexed: 12/31/2022]
Abstract
The mechanisms underlying synaptic differentiation, which involves neuronal membrane and cytoskeletal remodeling, are not completely understood. We performed a targeted RNAi-mediated screen of Drosophila BAR-domain proteins and identified islet cell autoantigen 69 kDa (ICA69) as one of the key regulators of morphological differentiation of the larval neuromuscular junction (NMJ). We show that Drosophila ICA69 colocalizes with α-Spectrin at the NMJ. The conserved N-BAR domain of ICA69 deforms liposomes in vitro Full-length ICA69 and the ICAC but not the N-BAR domain of ICA69 induce filopodia in cultured cells. Consistent with its cytoskeleton regulatory role, ICA69 mutants show reduced α-Spectrin immunoreactivity at the larval NMJ. Manipulating levels of ICA69 or its interactor PICK1 alters the synaptic level of ionotropic glutamate receptors (iGluRs). Moreover, reducing PICK1 or Rab2 levels phenocopies ICA69 mutation. Interestingly, Rab2 regulates not only synaptic iGluR but also ICA69 levels. Thus, our data suggest that: (1) ICA69 regulates NMJ organization through a pathway that involves PICK1 and Rab2, and (2) Rab2 functions genetically upstream of ICA69 and regulates NMJ organization and targeting/retention of iGluRs by regulating ICA69 levels.
Collapse
Affiliation(s)
- Bhagaban Mallik
- Department of Biological Sciences, AB-3, Indian Institute of Science Education and Research, Bhauri, Bhopal, Madhya Pradesh 462066, India
| | - Manish Kumar Dwivedi
- Department of Biological Sciences, AB-3, Indian Institute of Science Education and Research, Bhauri, Bhopal, Madhya Pradesh 462066, India
| | - Zeeshan Mushtaq
- Department of Biological Sciences, AB-3, Indian Institute of Science Education and Research, Bhauri, Bhopal, Madhya Pradesh 462066, India
| | - Manisha Kumari
- National Institute of Plant Genome Research (NIPGR), New Delhi 110067, India
| | - Praveen Kumar Verma
- National Institute of Plant Genome Research (NIPGR), New Delhi 110067, India
| | - Vimlesh Kumar
- Department of Biological Sciences, AB-3, Indian Institute of Science Education and Research, Bhauri, Bhopal, Madhya Pradesh 462066, India
| |
Collapse
|
148
|
Lanzetti L, Di Fiore PP. Behind the Scenes: Endo/Exocytosis in the Acquisition of Metastatic Traits. Cancer Res 2017; 77:1813-1817. [PMID: 28373181 DOI: 10.1158/0008-5472.can-16-3403] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Accepted: 01/01/2017] [Indexed: 11/16/2022]
Abstract
Alterations of endo/exocytic proteins have long been associated with malignant transformation, and genes encoding membrane trafficking proteins have been identified as bona fide drivers of tumorigenesis. Focusing on the mechanisms underlying the impact of endo/exocytic proteins in cancer, a scenario emerges in which altered trafficking routes/networks appear to be preferentially involved in the acquisition of prometastatic traits. This involvement in metastasis frequently occurs through the integration of programs leading to migratory/invasive phenotypes, survival and resistance to environmental stresses, epithelial-to-mesenchymal transition, and the emergence of cancer stem cells. These findings might have important implications in the clinical setting for the development of metastasis-specific drugs and for patient stratification to optimize the use of available therapies. Cancer Res; 77(8); 1813-7. ©2017 AACR.
Collapse
Affiliation(s)
- Letizia Lanzetti
- Membrane Trafficking Laboratory at Candiolo Cancer Institute - FPO, IRCCS, Candiolo, Italy. .,Department of Oncology, University of Turin Medical School, Turin, Italy
| | - Pier Paolo Di Fiore
- IFOM, The FIRC Institute for Molecular Oncology Foundation, Milan, Italy. .,DIPO, Department of Oncology and Hemato-Oncology, University of Milan, Milan, Italy.,Molecular Medicine Program, European Institute of Oncology, Milan, Italy
| |
Collapse
|
149
|
Neefjes J, Jongsma MML, Berlin I. Stop or Go? Endosome Positioning in the Establishment of Compartment Architecture, Dynamics, and Function. Trends Cell Biol 2017; 27:580-594. [PMID: 28363667 DOI: 10.1016/j.tcb.2017.03.002] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 03/03/2017] [Accepted: 03/06/2017] [Indexed: 02/03/2023]
Abstract
The endosomal system constitutes a key negotiator between the environment of a cell and its internal affairs. Comprised of a complex membranous network, wherein each vesicle can in principle move autonomously throughout the cell, the endosomal system operates as a coherent unit to optimally face external challenges and maintain homeostasis. Our appreciation of how individual endosomes are controlled in time and space to best serve their collective purpose has evolved dramatically in recent years. In light of these efforts, the endoplasmic reticulum (ER) - with its expanse of membranes permeating the cytoplasmic space - has emerged as a potent spatiotemporal organizer of endosome biology. We review the latest advances in our understanding of the mechanisms underpinning endosomal transport and positioning, with emphasis on the contributions from the ER, and offer a perspective on how the interplay between these aspects shapes the architecture and dynamics of the endosomal system and drives its myriad cellular functions.
Collapse
Affiliation(s)
- Jacques Neefjes
- Department of Chemical Immunology, Leiden University Medical Center (LUMC), Einthovenweg 20, 2333 ZC Leiden, The Netherlands
| | - Marlieke M L Jongsma
- Department of Immunopathology, Sanquin Research and Landsteiner Laboratory, Academic Medical Center (AMC)/Universiteit van Amsterdam (UvA), Plesmanlaan 125, 1066 CX Amsterdam, The Netherlands
| | - Ilana Berlin
- Department of Chemical Immunology, Leiden University Medical Center (LUMC), Einthovenweg 20, 2333 ZC Leiden, The Netherlands.
| |
Collapse
|
150
|
Caviglia S, Flores-Benitez D, Lattner J, Luschnig S, Brankatschk M. Rabs on the fly: Functions of Rab GTPases during development. Small GTPases 2017; 10:89-98. [PMID: 28118081 PMCID: PMC6380344 DOI: 10.1080/21541248.2017.1279725] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The organization of intracellular transport processes is adapted specifically to different cell types, developmental stages, and physiologic requirements. Some protein traffic routes are universal to all cells and constitutively active, while other routes are cell-type specific, transient, and induced under particular conditions only. Small GTPases of the Rab (Ras related in brain) subfamily are conserved across eukaryotes and regulate most intracellular transit pathways. The complete sets of Rab proteins have been identified in model organisms, and molecular principles underlying Rab functions have been uncovered. Rabs provide intracellular landmarks that define intracellular transport sequences. Nevertheless, it remains a challenge to systematically map the subcellular distribution of all Rabs and their functional interrelations. This task requires novel tools to precisely describe and manipulate the Rab machinery in vivo. Here we discuss recent findings about Rab roles during development and we consider novel approaches to investigate Rab functions in vivo.
Collapse
Affiliation(s)
- Sara Caviglia
- a Danish Stem Cell Center (DanStem), University of Copenhagen , Copenhagen , Denmark.,c Institute of Molecular Life Sciences and Ph.D. Program in Molecular Life Sciences, University of Zurich , Zurich , Switzerland
| | - David Flores-Benitez
- b Max Planck Institute for Cell Biology and Genetics (MPI-CBG) , Dresden , Germany
| | - Johanna Lattner
- b Max Planck Institute for Cell Biology and Genetics (MPI-CBG) , Dresden , Germany
| | - Stefan Luschnig
- c Institute of Molecular Life Sciences and Ph.D. Program in Molecular Life Sciences, University of Zurich , Zurich , Switzerland.,d Institute of Neurobiology and Cluster of Excellence Cells-in-Motion (EXC 1003 - CiM), University of Münster , Münster , Germany
| | - Marko Brankatschk
- e The Biotechnological Center of the TU Dresden (BIOTEC) , Dresden , Germany
| |
Collapse
|