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Fowler PC, Garcia-Pardo ME, Simpson JC, O'Sullivan NC. NeurodegenERation: The Central Role for ER Contacts in Neuronal Function and Axonopathy, Lessons From Hereditary Spastic Paraplegias and Related Diseases. Front Neurosci 2019; 13:1051. [PMID: 31680803 PMCID: PMC6801308 DOI: 10.3389/fnins.2019.01051] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Accepted: 09/19/2019] [Indexed: 12/17/2022] Open
Abstract
The hereditary spastic paraplegias (HSPs) are a group of inherited neurodegenerative conditions whose characteristic feature is degeneration of the longest axons within the corticospinal tract which leads to progressive spasticity and weakness of the lower limbs. Though highly genetically heterogeneous, the majority of HSP cases are caused by mutations in genes encoding proteins that are responsible for generating and organizing the tubular endoplasmic reticulum (ER). Despite this, the role of the ER within neurons, particularly the long axons affected in HSP, is not well understood. Throughout axons, ER tubules make extensive contacts with other organelles, the cytoskeleton and the plasma membrane. At these ER contacts, protein complexes work in concert to perform specialized functions including organelle shaping, calcium homeostasis and lipid biogenesis, all of which are vital for neuronal survival and may be disrupted by HSP-causing mutations. In this article we summarize the proteins which mediate ER contacts, review the functions these contacts are known to carry out within neurons, and discuss the potential contribution of disruption of ER contacts to axonopathy in HSP.
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Affiliation(s)
- Philippa C Fowler
- UCD School of Biomolecular and Biomedical Science, UCD Conway Institute, University College Dublin, Dublin, Ireland
| | - M Elena Garcia-Pardo
- UCD School of Biomolecular and Biomedical Science, UCD Conway Institute, University College Dublin, Dublin, Ireland
| | - Jeremy C Simpson
- UCD School of Biology and Environmental Science, UCD Conway Institute, University College Dublin, Dublin, Ireland
| | - Niamh C O'Sullivan
- UCD School of Biomolecular and Biomedical Science, UCD Conway Institute, University College Dublin, Dublin, Ireland
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52
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Rab GTPases: Switching to Human Diseases. Cells 2019; 8:cells8080909. [PMID: 31426400 PMCID: PMC6721686 DOI: 10.3390/cells8080909] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Revised: 08/13/2019] [Accepted: 08/14/2019] [Indexed: 02/07/2023] Open
Abstract
Rab proteins compose the largest family of small GTPases and control the different steps of intracellular membrane traffic. More recently, they have been shown to also regulate cell signaling, division, survival, and migration. The regulation of these processes generally occurs through recruitment of effectors and regulatory proteins, which control the association of Rab proteins to membranes and their activation state. Alterations in Rab proteins and their effectors are associated with multiple human diseases, including neurodegeneration, cancer, and infections. This review provides an overview of how the dysregulation of Rab-mediated functions and membrane trafficking contributes to these disorders. Understanding the altered dynamics of Rabs and intracellular transport defects might thus shed new light on potential therapeutic strategies.
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53
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Harding P, Moosajee M. The Molecular Basis of Human Anophthalmia and Microphthalmia. J Dev Biol 2019; 7:jdb7030016. [PMID: 31416264 PMCID: PMC6787759 DOI: 10.3390/jdb7030016] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 08/08/2019] [Accepted: 08/08/2019] [Indexed: 12/16/2022] Open
Abstract
Human eye development is coordinated through an extensive network of genetic signalling pathways. Disruption of key regulatory genes in the early stages of eye development can result in aborted eye formation, resulting in an absent eye (anophthalmia) or a small underdeveloped eye (microphthalmia) phenotype. Anophthalmia and microphthalmia (AM) are part of the same clinical spectrum and have high genetic heterogeneity, with >90 identified associated genes. By understanding the roles of these genes in development, including their temporal expression, the phenotypic variation associated with AM can be better understood, improving diagnosis and management. This review describes the genetic and structural basis of eye development, focusing on the function of key genes known to be associated with AM. In addition, we highlight some promising avenues of research involving multiomic approaches and disease modelling with induced pluripotent stem cell (iPSC) technology, which will aid in developing novel therapies.
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Affiliation(s)
| | - Mariya Moosajee
- UCL Institute of Ophthalmology, London EC1V 9EL, UK.
- Moorfields Eye Hospital NHS Foundation Trust, London EC1V 2PD, UK.
- Great Ormond Street Hospital for Children NHS Foundation Trust, London WC1N 3JH, UK.
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54
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史 琳, 王 柯, 邓 玉, 王 莹, 朱 双, 杨 旭, 廖 文. [Role of lipophagy in the regulation of lipid metabolism and the molecular mechanism]. NAN FANG YI KE DA XUE XUE BAO = JOURNAL OF SOUTHERN MEDICAL UNIVERSITY 2019; 39:867-874. [PMID: 31340923 PMCID: PMC6765557 DOI: 10.12122/j.issn.1673-4254.2019.07.19] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Indexed: 01/02/2023]
Abstract
Recent studies have discovered a selective autophagy-lipophagy, which can selectively identify and degrade lipids and plays an important role in regulating cellular lipid metabolism and maintaining intracellular lipid homeostasis. The process of lipophagy can be directly or indirectly regulated by genes, enzymes, transcriptional regulators and other factors. This review examines the role of lipophagy in reducing liver lipid content, regulating pancreatic lipid metabolism, and regulating adipose tissue differentiation, and summarizes the findings of the molecules (Rab GTPase, enzymes, ion channels, transcription factors, small molecular substances) involved in the regulation of lipophagy, which points to new directions for the treatment of diseases caused by lipid accumulation.
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Affiliation(s)
- 琳娜 史
- 南方医科大学 南方医院营养科,广东 广州 510515Department of Nutrition, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China
| | - 柯 王
- 华南理工大学食品科学与工程学院,广东 广 州 510640College of Light Industry and Food Sciences, South China University of Technology, Guangzhou 510640, China
| | - 玉娣 邓
- 南方医科大学公共卫生学院,广东 广州 510515School of Public Health, Southern Medical University, Guangzhou 510515, China
| | - 莹娜 王
- 广州市三兴生物技术有限公司,广东 广州 510000Guangzhou Sanxing Biotechnology Co., Ltd., Guangzhou 510000, China
| | - 双玲 朱
- 中山大学附属第一医院,广东 广州 510080First Affiliated Hospital, Sun Yat- sen University, Guangzhou 510080, China
| | - 旭珊 杨
- 南方医科大学公共卫生学院,广东 广州 510515School of Public Health, Southern Medical University, Guangzhou 510515, China
| | - 文镇 廖
- 南方医科大学公共卫生学院,广东 广州 510515School of Public Health, Southern Medical University, Guangzhou 510515, China
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55
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RAB18 modulates autophagy in human stellate cells. J Clin Lipidol 2019; 13:832-838. [PMID: 31563421 DOI: 10.1016/j.jacl.2019.07.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2019] [Revised: 07/06/2019] [Accepted: 07/16/2019] [Indexed: 12/13/2022]
Abstract
BACKGROUND Macroautophagy (or autophagy) is a conserved degradative pathway that breaks down sequestered cytoplasmic proteins and organelles in specialized double-membrane compartments called autophagosomes that fuse with lysosomes. Several proteins orchestrate this process, specifically Rab GTPases that are master regulators of molecular trafficking. RAB18 GTPase, a known mediator of stellate cell activation, is known to modulate autophagic flux in fibroblasts. However, its role in autophagy is unexplored in hepatic stellate cells. OBJECTIVE The aim of this study was to investigate the role of RAB18 in modulating autophagy in hepatic stellate cells. METHODS Role of RAB18 was determined by genetic depletion, pharmacologic inhibition, and overexpression studies to monitor autophagy flux and proteostasis in human LX2 stellate cell line. RESULTS RAB18 knockdown increases autophagy flux and regulates proteostasis. LX2 cells stimulated with transforming growth factor-beta robustly increases expression of profibrotic genes such as COL1A1 and ACTA2 along with RAB18 and its guanine nucleotide exchange factor, RAB3GAP1. CONCLUSION The study elucidates a role for RAB18 in autophagy and regulation of proteostasis in human stellate cells. Molecular insights into this process can provide therapeutic opportunities for intervention in liver fibrosis.
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56
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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.
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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.
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57
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Rasika S, Passemard S, Verloes A, Gressens P, El Ghouzzi V. Golgipathies in Neurodevelopment: A New View of Old Defects. Dev Neurosci 2019; 40:396-416. [PMID: 30878996 DOI: 10.1159/000497035] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Accepted: 01/16/2019] [Indexed: 11/19/2022] Open
Abstract
The Golgi apparatus (GA) is involved in a whole spectrum of activities, from lipid biosynthesis and membrane secretion to the posttranslational processing and trafficking of most proteins, the control of mitosis, cell polarity, migration and morphogenesis, and diverse processes such as apoptosis, autophagy, and the stress response. In keeping with its versatility, mutations in GA proteins lead to a number of different disorders, including syndromes with multisystem involvement. Intriguingly, however, > 40% of the GA-related genes known to be associated with disease affect the central or peripheral nervous system, highlighting the critical importance of the GA for neural function. We have previously proposed the term "Golgipathies" in relation to a group of disorders in which mutations in GA proteins or their molecular partners lead to consequences for brain development, in particular postnatal-onset microcephaly (POM), white-matter defects, and intellectual disability (ID). Here, taking into account the broader role of the GA in the nervous system, we refine and enlarge this emerging concept to include other disorders whose symptoms may be indicative of altered neurodevelopmental processes, from neurogenesis to neuronal migration and the secretory function critical for the maturation of postmitotic neurons and myelination.
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Affiliation(s)
- Sowmyalakshmi Rasika
- NeuroDiderot, INSERM UMR1141, Université Paris Diderot, Sorbonne Paris Cité, Paris, France.,AP HP, Hôpital Robert Debré, UF de Génétique Clinique, Paris, France
| | - Sandrine Passemard
- NeuroDiderot, INSERM UMR1141, Université Paris Diderot, Sorbonne Paris Cité, Paris, France.,AP HP, Hôpital Robert Debré, UF de Génétique Clinique, Paris, France
| | - Alain Verloes
- NeuroDiderot, INSERM UMR1141, Université Paris Diderot, Sorbonne Paris Cité, Paris, France.,AP HP, Hôpital Robert Debré, UF de Génétique Clinique, Paris, France
| | - Pierre Gressens
- NeuroDiderot, INSERM UMR1141, Université Paris Diderot, Sorbonne Paris Cité, Paris, France.,Centre for the Developing Brain, Division of Imaging Sciences and Biomedical Engineering, King's College London, King's Health Partners, St. Thomas' Hospital, London, United Kingdom
| | - Vincent El Ghouzzi
- NeuroDiderot, INSERM UMR1141, Université Paris Diderot, Sorbonne Paris Cité, Paris, France,
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58
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Handley MT, Reddy K, Wills J, Rosser E, Kamath A, Halachev M, Falkous G, Williams D, Cox P, Meynert A, Raymond ES, Morrison H, Brown S, Allan E, Aligianis I, Jackson AP, Ramsahoye BH, von Kriegsheim A, Taylor RW, Finch AJ, FitzPatrick DR. ITPase deficiency causes a Martsolf-like syndrome with a lethal infantile dilated cardiomyopathy. PLoS Genet 2019; 15:e1007605. [PMID: 30856165 PMCID: PMC6428344 DOI: 10.1371/journal.pgen.1007605] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 03/21/2019] [Accepted: 12/27/2018] [Indexed: 12/30/2022] Open
Abstract
Typical Martsolf syndrome is characterized by congenital cataracts, postnatal microcephaly, developmental delay, hypotonia, short stature and biallelic hypomorphic mutations in either RAB3GAP1 or RAB3GAP2. Genetic analysis of 85 unrelated "mutation negative" probands with Martsolf or Martsolf-like syndromes identified two individuals with different homozygous null mutations in ITPA, the gene encoding inosine triphosphate pyrophosphatase (ITPase). Both probands were from multiplex families with a consistent, lethal and highly distinctive disorder; a Martsolf-like syndrome with infantile-onset dilated cardiomyopathy. Severe ITPase-deficiency has been previously reported with infantile epileptic encephalopathy (MIM 616647). ITPase acts to prevent incorporation of inosine bases (rI/dI) into RNA and DNA. In Itpa-null cells dI was undetectable in genomic DNA. dI could be identified at a low level in mtDNA without detectable mitochondrial genome instability, mtDNA depletion or biochemical dysfunction of the mitochondria. rI accumulation was detectable in proband-derived lymphoblastoid RNA. In Itpa-null mouse embryos rI was detectable in the brain and kidney with the highest level seen in the embryonic heart (rI at 1 in 385 bases). Transcriptome and proteome analysis in mutant cells revealed no major differences with controls. The rate of transcription and the total amount of cellular RNA also appeared normal. rI accumulation in RNA-and by implication rI production-correlates with the severity of organ dysfunction in ITPase deficiency but the basis of the cellulopathy remains cryptic. While we cannot exclude cumulative minor effects, there are no major anomalies in the production, processing, stability and/or translation of mRNA.
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Affiliation(s)
- Mark T. Handley
- MRC Human Genetics Unit, Institute of Genomic and Molecular Medicine, University of Edinburgh, Edinburgh, United Kingdom
- Section of Genetics, Leeds Institute of Biomedical and Clinical Sciences, University of Leeds, Leeds, United Kigndom
| | - Kaalak Reddy
- MRC Human Genetics Unit, Institute of Genomic and Molecular Medicine, University of Edinburgh, Edinburgh, United Kingdom
- University of Florida College of Medicine, Center for NeuroGenetics, Gainesville, United States of America
| | - Jimi Wills
- Edinburgh Cancer Research Centre, MRC Institute of Genomic and Molecular Medicine, University of Edinburgh, Edinburgh, United Kingdom
| | - Elisabeth Rosser
- Department of Clinical Genetics, Great Ormond St Hospital, London, United Kingdom
| | - Archith Kamath
- Medical School, University of Oxford, John Radcliffe Hospital Oxford United Kingdom
| | - Mihail Halachev
- MRC Human Genetics Unit, Institute of Genomic and Molecular Medicine, University of Edinburgh, Edinburgh, United Kingdom
| | - Gavin Falkous
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Denise Williams
- Department of Clinical Genetics, Birmingham Women's and Children's NHSFT, Birmingham, United Kingdom
| | - Phillip Cox
- Department of Histopathology, Birmingham Women's and Children's NHSFT, Birmingham United Kingdom
| | - Alison Meynert
- MRC Human Genetics Unit, Institute of Genomic and Molecular Medicine, University of Edinburgh, Edinburgh, United Kingdom
| | - Eleanor S. Raymond
- MRC Human Genetics Unit, Institute of Genomic and Molecular Medicine, University of Edinburgh, Edinburgh, United Kingdom
| | - Harris Morrison
- MRC Human Genetics Unit, Institute of Genomic and Molecular Medicine, University of Edinburgh, Edinburgh, United Kingdom
| | - Stephen Brown
- MRC Human Genetics Unit, Institute of Genomic and Molecular Medicine, University of Edinburgh, Edinburgh, United Kingdom
| | - Emma Allan
- CBS-IGMM Transgenic Unit, University of Edinburgh, Edinburgh, United Kingdom
| | - Irene Aligianis
- MRC Human Genetics Unit, Institute of Genomic and Molecular Medicine, University of Edinburgh, Edinburgh, United Kingdom
| | - Andrew P. Jackson
- MRC Human Genetics Unit, Institute of Genomic and Molecular Medicine, University of Edinburgh, Edinburgh, United Kingdom
| | - Bernard H. Ramsahoye
- Centre for Genetic and Experimental Medicine, Institute of Genomic and Molecular Medicine, University of Edinburgh, Edinburgh, United Kingdom
| | - Alex von Kriegsheim
- Edinburgh Cancer Research Centre, MRC Institute of Genomic and Molecular Medicine, University of Edinburgh, Edinburgh, United Kingdom
| | - Robert W. Taylor
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Andrew J. Finch
- Edinburgh Cancer Research Centre, MRC Institute of Genomic and Molecular Medicine, University of Edinburgh, Edinburgh, United Kingdom
| | - David R. FitzPatrick
- MRC Human Genetics Unit, Institute of Genomic and Molecular Medicine, University of Edinburgh, Edinburgh, United Kingdom
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59
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Koparir A, Karatas OF, Yilmaz SS, Suer I, Ozer B, Yuceturk B, Ozen M. Revealing the functions of novel mutations in RAB3GAP1
in Martsolf and Warburg micro syndromes. Am J Med Genet A 2019; 179:579-587. [DOI: 10.1002/ajmg.a.61065] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Revised: 01/17/2019] [Accepted: 01/17/2019] [Indexed: 12/30/2022]
Affiliation(s)
- Asuman Koparir
- Department of Internal Medicine, Division of Medical Genetics; Istanbul University; Istanbul Turkey
| | - Omer Faruk Karatas
- Molecular Biology and Genetics Department; Erzurum Technical University; Erzurum Turkey
| | - Seda Salman Yilmaz
- Department of Medical Genetics; Istanbul University, Cerrahpasa Medical School; Istanbul Turkey
| | - Ilknur Suer
- Department of Internal Medicine, Division of Medical Genetics; Istanbul University; Istanbul Turkey
| | - Bugra Ozer
- Advanced Genomics and Bioinformatics Research Center; The Scientific and Technological Research Council of Turkey (TUBITAK-BILGEM); Kocaeli Turkey
| | - Betul Yuceturk
- Advanced Genomics and Bioinformatics Research Center; The Scientific and Technological Research Council of Turkey (TUBITAK-BILGEM); Kocaeli Turkey
| | - Mustafa Ozen
- Department of Medical Genetics; Istanbul University, Cerrahpasa Medical School; Istanbul Turkey
- Department of Pathology and Immunology; Baylor College of Medicine; Houston Texas
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60
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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.
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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.
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61
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Elgner F, Hildt E, Bender D. Relevance of Rab Proteins for the Life Cycle of Hepatitis C Virus. Front Cell Dev Biol 2018; 6:166. [PMID: 30564577 PMCID: PMC6288913 DOI: 10.3389/fcell.2018.00166] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Accepted: 11/20/2018] [Indexed: 12/18/2022] Open
Abstract
Although potent direct-acting antiviral drugs for the treatment of chronic hepatitis C virus (HCV) infection are licensed, there are more than 70 million individuals suffering from chronic HCV infection. In light of the limited access to these drugs, high costs, and a lot of undiagnosed cases, it is expected that the number of HCV cases will not decrease worldwide in the next years. Therefore, and due to the paradigmatic character of HCV for deciphering the crosstalk between viral pathogens and the host cell, characterization of HCV life cycle remains a challenge. HCV belongs to the family of Flaviviridae. As an enveloped virus HCV life cycle depends in many steps on intracellular trafficking. Rab GTPases, a large family of small GTPases, play a central role in intracellular trafficking processes controlling fusion, uncoating, vesicle budding, motility by recruiting specific effector proteins. This review describes the relevance of various Rab proteins for the different steps of the HCV life cycle.
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Affiliation(s)
- Fabian Elgner
- Department of Virology, Paul-Ehrlich-Institut, Langen, Germany
| | - Eberhard Hildt
- Department of Virology, Paul-Ehrlich-Institut, Langen, Germany
| | - Daniela Bender
- Department of Virology, Paul-Ehrlich-Institut, Langen, Germany
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62
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Abstract
The genetic control of pubertal timing has been a field of active investigation for the last decade, but remains a fascinating and mysterious conundrum. Self-limited delayed puberty (DP), also known as constitutional delay of growth and puberty, represents the extreme end of normal pubertal timing, and is the commonest cause of DP in both boys and girls. Familial self-limited DP has a clear genetic basis. It is a highly heritable condition, which often segregates in an autosomal dominant pattern (with or without complete penetrance) in the majority of families. However, the underlying neuroendocrine pathophysiology and genetic regulation has been largely unknown. Very recently novel gene discoveries from next generation sequencing studies have provided insights into the genetic mutations that lead to familial DP. Further understanding has come from sequencing genes known to cause GnRH deficiency, next generation sequencing studies in patients with early puberty, and from large-scale genome wide association studies in the general population. Results of these studies suggest that the genetic basis of DP is likely to be highly heterogeneous. Abnormalities of GnRH neuronal development, function, and its downstream pathways, metabolic and energy homeostatic derangements, and transcriptional regulation of the hypothalamic-pituitary-gonadal axis may all lead to DP. This variety of different pathogenic mechanisms affecting the release of the puberty 'brake' may take place in several age windows between fetal life and puberty.
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Affiliation(s)
- S R Howard
- Centre for Endocrinology, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, EC1M 6BQ, UK.
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63
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Wu B, Qi R, Liu X, Qian L, Wu Z. Rab18 overexpression promotes proliferation and chemoresistance through regulation of mitochondrial function in human gastric cancer. Onco Targets Ther 2018; 11:7805-7820. [PMID: 30464528 PMCID: PMC6225851 DOI: 10.2147/ott.s170829] [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] [Indexed: 11/23/2022] Open
Abstract
Background Dysregulation of Rab18 has been implicated in human cancers. However, its clinical significance and biological function in gastric cancer have not been investigated. Methods We examined Rab18 expression in gastric cancer tissues using immunohistochemistry. We used SNU-1 and AGS cell lines for plasmid and siRNA transfection respectively. MTT, colony formation assay, cell cycle analysis, matrigel invasion, wound healing assay, AnnexinV/PI analysis and western blotting were used to examine the biological effect and mechanism of Rab18 in gastric cancer cell lines. Results Rab18 protein expression was upregulated in gastric cancer tissues and this correlated with advanced stage and poor prognosis. Rab18 overexpression promoted proliferation in vitro and in vivo. Cell cycle analysis showed that Rab18 overexpression upregulated, while its depletion downregulated S phase percentage. Matrigel invasion and wound healing assays indicated that Rab18 positively regulated SNU-1 cell invasion and migration while its knockdown inhibited AGS cell invasion and migration. Rab18 maintained cell viability and downregulated apoptosis after cisplatin treatment, with upregulated mitochondrial membrane potential and downregulated mitochondrial reactive oxygen species (ROS) production. Rab18 overexpression upregulated p-Rb, survivin while downregulated cytochrome c, cleaved caspase-3 and cleaved PARP. Conclusion In conclusion, our results indicate that Rab18 promoted gastric cancer growth and chemoresistance, possibly through regulation of mitochondrial function and survivin.
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Affiliation(s)
- Binge Wu
- Department of General Surgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China,
| | - Rui Qi
- Department of Ophthalmology, The First Affiliated Hospital of Baotou Medical College, Baotou, China
| | - Xu Liu
- Department of Ophthalmology, The First Affiliated Hospital of Baotou Medical College, Baotou, China
| | - Lehua Qian
- Department of Ophthalmology, The First Affiliated Hospital of Baotou Medical College, Baotou, China
| | - Zhongjun Wu
- Department of General Surgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China,
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64
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Cortès-Saladelafont E, Lipstein N, García-Cazorla À. Presynaptic disorders: a clinical and pathophysiological approach focused on the synaptic vesicle. J Inherit Metab Dis 2018; 41:1131-1145. [PMID: 30022305 DOI: 10.1007/s10545-018-0230-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 06/23/2018] [Accepted: 07/02/2018] [Indexed: 12/12/2022]
Abstract
The aim of this report is to present a tentative clinical and pathophysiological approach to diseases affecting the neuronal presynaptic terminal, with a major focus on synaptic vesicles (SVs). Diseases are classified depending on which step of the neurobiology of the SV is predominantly affected: (1) biogenesis of vesicle precursors in the neuronal soma; (2) transport along the axon; (3) vesicle cycle at the presynaptic terminal (exocytosis-endocytosis cycle, with the main purpose of neurotransmitter release). Given that SVs have been defined as individual organelles, we highlight the link between the biological processes disturbed by genetic mutations and the clinical presentation of these disorders. The great majority of diseases may present as epileptic encephalopathies, intellectual disability (syndromic or nonsyndromic) with/without autism spectrum disorder (and other neuropsychiatric symptoms), and movement disorders. These symptoms may overlap and present in patients as a combination of clinical signs that results in the spectrum of the synaptopathies. A small number of diseases may also exhibit neuromuscular signs. In general, SV disorders tend to be severe, early encephalopathies that interfere with neurodevelopment. As a consequence, developmental delay and intellectual disability are constant in almost all the defects described. Considering that some of these diseases might mimic other neurometabolic conditions (and in particular treatable disorders), an initial extensive metabolic workup should always be considered. Further knowledge into pathophysiological mechanisms and biomarkers, as well as descriptions of new presynaptic disorders, will probably take place in the near future.
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Affiliation(s)
- Elisenda Cortès-Saladelafont
- Department of Neurology, Neurometabolic Unit and Synaptic Metabolism Laboratory, Institut Pediàtric de Recerca and CIBERER, ISCIII, Hospital Sant Joan de Déu, Passeig Sant Joan de Déu, 2, 08950, Esplugues, Barcelona, Spain
| | - Noa Lipstein
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Àngels García-Cazorla
- Department of Neurology, Neurometabolic Unit and Synaptic Metabolism Laboratory, Institut Pediàtric de Recerca and CIBERER, ISCIII, Hospital Sant Joan de Déu, Passeig Sant Joan de Déu, 2, 08950, Esplugues, Barcelona, Spain.
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65
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Loukovitis E, Sfakianakis K, Syrmakesi P, Tsotridou E, Orfanidou M, Bakaloudi DR, Stoila M, Kozei A, Koronis S, Zachariadis Z, Tranos P, Kozeis N, Balidis M, Gatzioufas Z, Fiska A, Anogeianakis G. Genetic Aspects of Keratoconus: A Literature Review Exploring Potential Genetic Contributions and Possible Genetic Relationships with Comorbidities. Ophthalmol Ther 2018; 7:263-292. [PMID: 30191404 PMCID: PMC6258591 DOI: 10.1007/s40123-018-0144-8] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Indexed: 01/24/2023] Open
Abstract
Introduction Keratoconus (KC) is a complex, genetically heterogeneous, multifactorial degenerative disorder that is accompanied by corneal ectasia which usually progresses asymmetrically. With an incidence of approximately 1 per 2000 and 2 cases per 100,000 population presenting annually, KC follows an autosomal recessive or dominant pattern of inheritance and is, apparently, associated with genes that interact with environmental, genetic, and/or other factors. This is an important consideration in refractive surgery in the case of familial KC, given the association of KC with other genetic disorders and the imbalance between dizygotic twins. The present review attempts to identify the genetic loci contributing to the different KC clinical presentations and relate them to the common genetically determined comorbidities associated with KC. Methods The PubMed, MEDLINE, Google Scholar, and GeneCards databases were screened for KC-related articles published in English between January 2006 and November 2017. Keyword combinations of “keratoconus,” “risk factor(s),” “genetics,” “genes,” “genetic association(s),” and “cornea” were used. In total, 217 articles were retrieved and analyzed, with greater weight placed on the more recent literature. Further bibliographic research based on the 217 articles revealed another 124 relevant articles that were included in this review. Using the reviewed literature, an attempt was made to correlate genes and genetic risk factors with KC characteristics and genetically related comorbidities associated with KC based on genome-wide association studies, family-based linkage analysis, and candidate-gene approaches. Results An association matrix between known KC-related genes and KC symptoms and/or clinical signs together with an association matrix between identified KC genes and genetically related KC comorbidities/syndromes were constructed. Conclusion Twenty-four genes were identified as potential contributors to KC and 49 KC-related comorbidities/syndromes were found. More than 85% of the known KC-related genes are involved in glaucoma, Down syndrome, connective tissue disorders, endothelial dystrophy, posterior polymorphous corneal dystrophy, and cataract.
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Affiliation(s)
| | - Konstantinos Sfakianakis
- Division of Surgical Anatomy, Laboratory of Anatomy, Medical School, Democritus University of Thrace, University Campus, Alexandroupolis, Greece
| | - Panagiota Syrmakesi
- AHEPA University Hospital, Thessaloníki, Greece.,Ophthalmica Eye Institute, Thessaloníki, Greece
| | - Eleni Tsotridou
- Ophthalmica Eye Institute, Thessaloníki, Greece.,Faculty of Medicine, Aristotle University of Thessaloniki, Thessaloníki, Greece
| | - Myrsini Orfanidou
- Ophthalmica Eye Institute, Thessaloníki, Greece.,Faculty of Medicine, Aristotle University of Thessaloniki, Thessaloníki, Greece
| | - Dimitra Rafailia Bakaloudi
- Ophthalmica Eye Institute, Thessaloníki, Greece.,Faculty of Medicine, Aristotle University of Thessaloniki, Thessaloníki, Greece
| | - Maria Stoila
- Ophthalmica Eye Institute, Thessaloníki, Greece.,Faculty of Medicine, Aristotle University of Thessaloniki, Thessaloníki, Greece
| | - Athina Kozei
- Ophthalmica Eye Institute, Thessaloníki, Greece.,School of Pharmacology, University of Nicosia, Makedonitissis, Nicosia, Cyprus
| | | | | | | | | | | | - Zisis Gatzioufas
- Department of Ophthalmology, Cornea, Cataract and Refractive Surgery, University Hospital Basel, Basel, Switzerland
| | - Aliki Fiska
- Laboratory of Anatomy, Medical School, Democritus University of Thrace, University Campus, Alexandroupolis, Greece
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66
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Hor CH, Tang BL, Goh EL. Rab23 and developmental disorders. Rev Neurosci 2018; 29:849-860. [DOI: 10.1515/revneuro-2017-0110] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Accepted: 03/03/2018] [Indexed: 02/07/2023]
Abstract
Abstract
Rab23 is a conserved member of the Rab family of small GTPases that regulates membrane trafficking in eukaryotes. It is unique amongst the Rabs in terms of its implicated role in mammalian development, as originally illustrated by the embryonic lethality and open neural tube phenotype of a spontaneous mouse mutant that carries homozygous mutation of open brain, a gene encoding Rab23. Rab23 was initially identified to act as an antagonist of Sonic hedgehog (Shh) signaling, and has since been implicated in a number of physiological and pathological roles, including oncogenesis. Interestingly, RAB23 null allele homozygosity in humans is not lethal, but instead causes the developmental disorder Carpenter’s syndrome (CS), which is characterized by craniofacial malformations, polysyndactyly, obesity and intellectual disability. CS bears some phenotypic resemblance to a spectrum of hereditary defects associated with the primary cilium, or the ciliopathies. Recent findings have in fact implicated Rab23 in protein traffic to the primary cilium, thus linking it with the primary cellular locale of Shh signaling. Rab23 also has Shh and cilia-independent functions. It is known to mediate the expression of Nodal at the mouse left lateral plate mesoderm and Kupffer’s vesicle, the zebrafish equivalent of the mouse node. It is thus important for the left-right patterning of vertebrate embryos. In this review, we discuss the developmental disorders associated with Rab23 and attempt to relate its cellular activities to its roles in development.
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Affiliation(s)
- Catherine H.H. Hor
- Neuroscience Academic Clinical Programme, Duke-NUS Medical School , 8 College Road , Singapore 169857 , Singapore
- Department of Research , National Neuroscience Institute , Singapore 308433 , Singapore
| | - Bor Luen Tang
- Department of Biochemistry , Yong Loo Lin School of Medicine , National University of Singapore , Singapore 117597 , Singapore
- NUS Graduate School for Integrative Sciences and Engineering , National University of Singapore, Medical Drive , Singapore 117456 , Singapore
| | - Eyleen L.K. Goh
- Neuroscience Academic Clinical Programme, Duke-NUS Medical School , 8 College Road , Singapore 169857 , Singapore
- Department of Research , National Neuroscience Institute , Singapore 308433 , Singapore
- Department of Physiology , Yong Loo Lin School of Medicine , National University of Singapore , 8 Medical Drive , Singapore 117597 , Singapore
- KK Research Center, KK Women’s and Children’s Hospital , Singapore 229899 , Singapore
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67
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Xu S, Zhang X, Liu P. Lipid droplet proteins and metabolic diseases. Biochim Biophys Acta Mol Basis Dis 2018; 1864:1968-1983. [DOI: 10.1016/j.bbadis.2017.07.019] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Revised: 07/14/2017] [Accepted: 07/19/2017] [Indexed: 12/13/2022]
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68
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Genetics and mechanisms leading to human cortical malformations. Semin Cell Dev Biol 2018; 76:33-75. [DOI: 10.1016/j.semcdb.2017.09.031] [Citation(s) in RCA: 74] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Revised: 09/21/2017] [Accepted: 09/21/2017] [Indexed: 02/06/2023]
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69
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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.
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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
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70
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Abstract
The endoplasmic reticulum (ER) is a morphologically dynamic organelle containing different membrane subdomains with distinct cellular functions. Numerous observations have revealed that ER stress response induced by disturbed ER homeostasis is linked to various neurological/neurodegenerative disorders. In contrast, recent findings unveil that ER structural derangements are linked to the progression of several neurological diseases. The derangements involve two distinct, and likely opposing pathways. One is dysfunction of ER dynamics machinery, leading to disruption of ER network organization. Another one is facilitation of pre-existing machinery, leading to generation of markedly-ordered de novo membranous structure. Restoring the ER network can be the effective way toward the cure of ER-deranged neurological disorders.
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Affiliation(s)
- Tomoyuki Yamanaka
- Laboratory of Structural Neuropathology, Graduate School of Brain Science, Doshisha University, Kyoto, Japan
| | - Nobuyuki Nukina
- Laboratory of Structural Neuropathology, Graduate School of Brain Science, Doshisha University, Kyoto, Japan
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71
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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.
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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
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72
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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.
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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
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73
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Cellular effects mediated by pathogenic LRRK2: homing in on Rab-mediated processes. Biochem Soc Trans 2017; 45:147-154. [PMID: 28202668 DOI: 10.1042/bst20160392] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Revised: 11/04/2016] [Accepted: 11/11/2016] [Indexed: 12/12/2022]
Abstract
Leucine-rich repeat kinase 2 (LRRK2) is a key player in the pathogenesis of Parkinson's disease. Mutations in LRRK2 are associated with increased kinase activity that correlates with cytotoxicity, indicating that kinase inhibitors may comprise promising disease-modifying compounds. However, before embarking on such strategies, detailed knowledge of the cellular deficits mediated by pathogenic LRRK2 in the context of defined and pathologically relevant kinase substrates is essential. LRRK2 has been consistently shown to impair various intracellular vesicular trafficking events, and recent studies have shown that LRRK2 can phosphorylate a subset of proteins that are intricately implicated in those processes. In light of these findings, we here review the link between cellular deficits in intracellular trafficking pathways and the LRRK2-mediated phosphorylation of those newly identified substrates.
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74
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Schulze RJ, Drižytė K, Casey CA, McNiven MA. Hepatic Lipophagy: New Insights into Autophagic Catabolism of Lipid Droplets in the Liver. Hepatol Commun 2017; 1:359-369. [PMID: 29109982 PMCID: PMC5669271 DOI: 10.1002/hep4.1056] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The liver is a central fat‐storage organ, making it especially susceptible to steatosis as well as subsequent inflammation and cirrhosis. The mechanisms by which the liver mobilizes stored lipid for energy production, however, remain incompletely defined. The catabolic process of autophagy, a well‐known process of bulk cytoplasmic recycling and cellular self‐regeneration, is a central regulator of lipid metabolism in the liver. In the past decade, numerous studies have examined a selective form of autophagy that specifically targets a unique neutral lipid storage organelle, the lipid droplet, to better understand the function for this process in hepatocellular fatty acid metabolism. In the liver (and other oxidative tissues), this specialized pathway, lipophagy, likely plays as important a role in lipid turnover as conventional lipase‐driven lipolysis. In this review, we highlight several recent studies that have contributed to our understanding about the regulation and effects of hepatic lipophagy. (Hepatology Communications 2017;1:359–369)
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Affiliation(s)
- Ryan J Schulze
- Department of Biochemistry and Molecular Biology and the Center for Digestive Diseases, Mayo Clinic, 200 1st St SW, Rochester, MN, 55905, USA
| | - Kristina Drižytė
- Department of Biochemistry and Molecular Biology and the Center for Digestive Diseases, Mayo Clinic, 200 1st St SW, Rochester, MN, 55905, USA.,Biochemistry and Molecular Biology Program, Mayo Clinic Graduate School of Biomedical Sciences, Mayo Clinic, 200 1st St SW, Rochester, MN 55905, USA
| | - Carol A Casey
- Department of Internal Medicine, University of Nebraska Medical Center, 988090 Nebraska Medical Center, Omaha, NE, 68198, USA.,Research Service, VA Nebraska-Western Iowa Health Care System (VA NWIHCS), Omaha, NE, 68198, USA
| | - Mark A McNiven
- Department of Biochemistry and Molecular Biology and the Center for Digestive Diseases, Mayo Clinic, 200 1st St SW, Rochester, MN, 55905, USA
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75
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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]
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76
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Feldmann A, Bekbulat F, Huesmann H, Ulbrich S, Tatzelt J, Behl C, Kern A. The RAB GTPase RAB18 modulates macroautophagy and proteostasis. Biochem Biophys Res Commun 2017; 486:738-743. [PMID: 28342870 DOI: 10.1016/j.bbrc.2017.03.112] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Accepted: 03/21/2017] [Indexed: 01/30/2023]
Abstract
Macroautophagy is a conserved degradative pathway and its deterioration is linked to disturbances in cellular proteostasis and multiple diseases. Here, we show that the RAB GTPase RAB18 modulates autophagy in primary human fibroblasts. The knockdown of RAB18 results in a decreased autophagic activity, while its overexpression enhances the degradative pathway. Importantly, this function of RAB18 is dependent on RAB3GAP1 and RAB3GAP2, which might act as RAB GEFs and stimulate the activity of the RAB GTPase. Moreover, the knockdown of RAB18 deteriorates proteostasis and results in the intracellular accumulation of ubiquitinated degradation-prone proteins. Thus, the RAB GTPase RAB18 is a positive modulator of autophagy and is relevant for the maintenance of cellular proteostasis.
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Affiliation(s)
- Anne Feldmann
- Institute of Pathobiochemistry, University Medical Center of the Johannes Gutenberg University, 55099 Mainz, Germany.
| | - Fazilet Bekbulat
- Institute of Pathobiochemistry, University Medical Center of the Johannes Gutenberg University, 55099 Mainz, Germany.
| | - Heike Huesmann
- Institute of Pathobiochemistry, University Medical Center of the Johannes Gutenberg University, 55099 Mainz, Germany.
| | - Sarah Ulbrich
- Department of Biochemistry of Neurodegenerative Diseases, Institute of Biochemistry und Pathobiochemistry, Ruhr University Bochum, 44801 Bochum, Germany.
| | - Jörg Tatzelt
- Department of Biochemistry of Neurodegenerative Diseases, Institute of Biochemistry und Pathobiochemistry, Ruhr University Bochum, 44801 Bochum, Germany.
| | - Christian Behl
- Institute of Pathobiochemistry, University Medical Center of the Johannes Gutenberg University, 55099 Mainz, Germany.
| | - Andreas Kern
- Institute of Pathobiochemistry, University Medical Center of the Johannes Gutenberg University, 55099 Mainz, Germany.
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77
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Jiang Z, Wang H, Zhang G, Zhao R, Bie T, Zhang R, Gao D, Xing L, Cao A. Characterization of a small GTP-binding protein gene TaRab18 from wheat involved in the stripe rust resistance. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2017; 113:40-50. [PMID: 28182966 DOI: 10.1016/j.plaphy.2017.01.025] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Revised: 12/27/2016] [Accepted: 01/27/2017] [Indexed: 05/24/2023]
Abstract
The stripe rust resistance gene, Yr26, is commonly used in wheat production. Identification of Yr26 resistance related genes is important for better understanding of the resistance mechanism. TaRab18, a putative small GTP-binding protein, was screened as a resistance regulated gene as it showed differential expression between the Yr26-containing resistant wheat and the susceptible wheat at different time points after Pst inoculation. TaRab18 contains four typical domains (GI to GIV) of the small GTP-binding proteins superfamily and five domains (RabF1 to RabF5) specific to the Rab subfamily. From the phylogenetic tree that TaRab18 was identified as belonging to the RABC1 subfamily. Chromosome location analysis indicated that TaRab18 and its homeoalles were on the homeologous group 7 chromosomes, and the Pst induced TaRab18 was on the 7 B chromosome. Functional analysis by virus induced gene silencing (VIGS) indicated that TaRab18 was positively involved in the stripe rust resistance through regulating the hypersensitive response, and Pst can develop on the leaves of TaRab18 silenced 92R137. However, over-expression of TaRab18 in susceptible Yangmai158 did not enhance its resistance dramatically, only from 9 grade in Yangmai158 to 8 grade in the transgenic plant. However, histological observation indicated that the transgenic plants with over-expressed TaRab18 showed a strong hypersensitive response at the early infection stage. The research herein, will improve our understanding of the roles of Rab in wheat resistance.
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Affiliation(s)
- Zhengning Jiang
- Key Laboratory of Crop Genetics and Germplasm Enhancement, Cytogenetics Institute, Nanjing Agricultural University/JCIC-MCP, Nanjing 210095, China; Key Laboratory of Wheat Biology and Genetic Improvement on Low and Middle Yangtze River Valley Wheat Region (Ministry of Agriculture), Institute of Agricultural Science of the Lixiahe District in Jiangsu Province, Yangzhou 225007, China.
| | - Hui Wang
- Key Laboratory of Crop Genetics and Germplasm Enhancement, Cytogenetics Institute, Nanjing Agricultural University/JCIC-MCP, Nanjing 210095, China.
| | - Guoqin Zhang
- Key Laboratory of Crop Genetics and Germplasm Enhancement, Cytogenetics Institute, Nanjing Agricultural University/JCIC-MCP, Nanjing 210095, China.
| | - Renhui Zhao
- Key Laboratory of Wheat Biology and Genetic Improvement on Low and Middle Yangtze River Valley Wheat Region (Ministry of Agriculture), Institute of Agricultural Science of the Lixiahe District in Jiangsu Province, Yangzhou 225007, China.
| | - Tongde Bie
- Key Laboratory of Wheat Biology and Genetic Improvement on Low and Middle Yangtze River Valley Wheat Region (Ministry of Agriculture), Institute of Agricultural Science of the Lixiahe District in Jiangsu Province, Yangzhou 225007, China.
| | - Ruiqi Zhang
- Key Laboratory of Crop Genetics and Germplasm Enhancement, Cytogenetics Institute, Nanjing Agricultural University/JCIC-MCP, Nanjing 210095, China.
| | - Derong Gao
- Key Laboratory of Wheat Biology and Genetic Improvement on Low and Middle Yangtze River Valley Wheat Region (Ministry of Agriculture), Institute of Agricultural Science of the Lixiahe District in Jiangsu Province, Yangzhou 225007, China.
| | - Liping Xing
- Key Laboratory of Crop Genetics and Germplasm Enhancement, Cytogenetics Institute, Nanjing Agricultural University/JCIC-MCP, Nanjing 210095, China.
| | - Aizhong Cao
- Key Laboratory of Crop Genetics and Germplasm Enhancement, Cytogenetics Institute, Nanjing Agricultural University/JCIC-MCP, Nanjing 210095, China.
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78
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Loiudice P, Napoli D, Ragone MC, Nardi M, Casini G. Novel RAB3GAP1 Mutations Causing Warburg Micro Syndrome in Two Italian Sisters. J Pediatr Neurosci 2017; 12:360-362. [PMID: 29675078 PMCID: PMC5890559 DOI: 10.4103/jpn.jpn_45_17] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
This report details two novel RAB3GAP1 mutations causing Warburg Micro syndrome, a rare autosomal recessive disorder characterized by multiple organ abnormalities involving the ocular, nervous, and endocrine systems. Two Italian sisters were referred to our department for the assessment of congenital bilateral cataracts. They also presented with microphthalmia, postnatal microcephaly, severe developmental delay, and hypotony. Perinatal investigations were negative for any toxins or infectious diseases during pregnancy, including toxoplasmosis, rubella, cytomegalovirus, and herpes virus. Genetic tests were performed on samples from probands and their parents, targeting a total of 114 genes. After sequence analysis of RAB3GAP1, two heterozygous changes were identified in both sisters: C.519G>A, p.(Trp173Ter) and c.2486T>A, p.(Leu829Ter). The identified mutations have not previously been described in the literature, but they affect critical regions of the gene, suggesting a legitimate causal relationship between the genetic alterations and the clinical features of the patients.
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Affiliation(s)
- Pasquale Loiudice
- Ophthalmology Unit, Department of Surgical, Medical, Molecular and Critical Area Pathology, University of Pisa, Pisa, Italy
| | - Debora Napoli
- BioSNS, Scuola Normale Superiore di Pisa, Pisa, Italy
| | - Maria Cristina Ragone
- Ophthalmology Unit, Department of Surgical, Medical, Molecular and Critical Area Pathology, University of Pisa, Pisa, Italy
| | - Marco Nardi
- Ophthalmology Unit, Department of Surgical, Medical, Molecular and Critical Area Pathology, University of Pisa, Pisa, Italy
| | - Giamberto Casini
- Ophthalmology Unit, Department of Surgical, Medical, Molecular and Critical Area Pathology, University of Pisa, Pisa, Italy
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79
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Li C, Luo X, Zhao S, Siu GK, Liang Y, Chan HC, Satoh A, Yu SS. COPI-TRAPPII activates Rab18 and regulates its lipid droplet association. EMBO J 2016; 36:441-457. [PMID: 28003315 DOI: 10.15252/embj.201694866] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Revised: 11/11/2016] [Accepted: 11/16/2016] [Indexed: 11/09/2022] Open
Abstract
The transport protein particle (TRAPP) was initially identified as a vesicle tethering factor in yeast and as a guanine nucleotide exchange factor (GEF) for Ypt1/Rab1. In mammals, structures and functions of various TRAPP complexes are beginning to be understood. We found that mammalian TRAPPII was a GEF for both Rab18 and Rab1. Inactivation of TRAPPII-specific subunits by various methods including siRNA depletion and CRISPR-Cas9-mediated deletion reduced lipolysis and resulted in aberrantly large lipid droplets. Recruitment of Rab18 onto lipid droplet (LD) surface was defective in TRAPPII-deleted cells, but the localization of Rab1 on Golgi was not affected. COPI regulates LD homeostasis. We found that the previously documented interaction between TRAPPII and COPI was also required for the recruitment of Rab18 to the LD We hypothesize that the interaction between COPI and TRAPPII helps bring TRAPPII onto LD surface, and TRAPPII, in turn, activates Rab18 and recruits it on the LD surface to facilitate its functions in LD homeostasis.
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Affiliation(s)
- Chunman Li
- Department of Anatomy, Histology and Developmental Biology, School of Basic Medical Sciences, Health Science Centre, Shenzhen University, Shenzhen, China.,School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China
| | - Xiaomin Luo
- School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China
| | - Shan Zhao
- School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China
| | - Gavin Ky Siu
- School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China
| | - Yongheng Liang
- Key Laboratory of Agricultural Environmental Microbiology of MOA, College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Hsiao Chang Chan
- School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China.,Epithelial Cell Biology Research Centre, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China
| | - Ayano Satoh
- The Graduate School of Natural Science and Technology, Okayama University, Okayama, Japan
| | - Sidney Sb Yu
- School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China .,Epithelial Cell Biology Research Centre, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China
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80
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Li Z, Schulze RJ, Weller SG, Krueger EW, Schott MB, Zhang X, Casey CA, Liu J, Stöckli J, James DE, McNiven MA. A novel Rab10-EHBP1-EHD2 complex essential for the autophagic engulfment of lipid droplets. SCIENCE ADVANCES 2016; 2:e1601470. [PMID: 28028537 PMCID: PMC5161429 DOI: 10.1126/sciadv.1601470] [Citation(s) in RCA: 111] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Accepted: 11/15/2016] [Indexed: 05/15/2023]
Abstract
The autophagic digestion of lipid droplets (LDs) through lipophagy is an essential process by which most cells catabolize lipids as an energy source. However, the cellular machinery used for the envelopment of LDs during autophagy is poorly understood. We report a novel function for a small Rab guanosine triphosphatase (GTPase) in the recruitment of adaptors required for the engulfment of LDs by the growing autophagosome. In hepatocytes stimulated to undergo autophagy, Rab10 activity is amplified significantly, concomitant with its increased recruitment to nascent autophagic membranes at the LD surface. Disruption of Rab10 function by small interfering RNA knockdown or expression of a GTPase-defective variant leads to LD accumulation. Finally, Rab10 activation during autophagy is essential for LC3 recruitment to the autophagosome and stimulates its increased association with the adaptor protein EHBP1 (EH domain binding protein 1) and the membrane-deforming adenosine triphosphatase EHD2 (EH domain containing 2) that, together, are essential in driving the activated "engulfment" of LDs during lipophagy in hepatocytes.
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Affiliation(s)
- Zhipeng Li
- Biochemistry and Molecular Biology Program, Mayo Graduate School, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA
- Department of Biochemistry and Molecular Biology and the Center for Digestive Diseases, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA
| | - Ryan J. Schulze
- Department of Biochemistry and Molecular Biology and the Center for Digestive Diseases, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA
- Corresponding author. (M.A.M.); (R.J.S.)
| | - Shaun G. Weller
- Department of Biochemistry and Molecular Biology and the Center for Digestive Diseases, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA
| | - Eugene W. Krueger
- Department of Biochemistry and Molecular Biology and the Center for Digestive Diseases, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA
| | - Micah B. Schott
- Department of Biochemistry and Molecular Biology and the Center for Digestive Diseases, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA
| | - Xiaodong Zhang
- Department of Biochemistry and Molecular Biology, Mayo Clinic Arizona, 13400 E Shea Boulevard, Scottsdale, AZ 85259, USA
| | - Carol A. Casey
- Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Jun Liu
- Department of Biochemistry and Molecular Biology, Mayo Clinic Arizona, 13400 E Shea Boulevard, Scottsdale, AZ 85259, USA
| | - Jacqueline Stöckli
- Charles Perkins Centre, School of Life and Environmental Sciences, University of Sydney, Sydney, New South Wales, Australia
| | - David E. James
- Charles Perkins Centre, School of Life and Environmental Sciences, University of Sydney, Sydney, New South Wales, Australia
- Sydney Medical School, University of Sydney, Sydney, New South Wales, Australia
| | - Mark A. McNiven
- Department of Biochemistry and Molecular Biology and the Center for Digestive Diseases, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA
- Corresponding author. (M.A.M.); (R.J.S.)
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81
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Blanco-Sánchez B, Clément A, Phillips JB, Westerfield M. Zebrafish models of human eye and inner ear diseases. Methods Cell Biol 2016; 138:415-467. [PMID: 28129854 DOI: 10.1016/bs.mcb.2016.10.006] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Eye and inner ear diseases are the most common sensory impairments that greatly impact quality of life. Zebrafish have been intensively employed to understand the fundamental mechanisms underlying eye and inner ear development. The zebrafish visual and vestibulo-acoustic systems are very similar to these in humans, and although not yet mature, they are functional by 5days post-fertilization (dpf). In this chapter, we show how the zebrafish has significantly contributed to the field of biomedical research and how researchers, by establishing disease models and meticulously characterizing their phenotypes, have taken the first steps toward therapies. We review here models for (1) eye diseases, (2) ear diseases, and (3) syndromes affecting eye and/or ear. The use of new genome editing technologies and high-throughput screening systems should increase considerably the speed at which knowledge from zebrafish disease models is acquired, opening avenues for better diagnostics, treatments, and therapies.
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Affiliation(s)
| | - A Clément
- University of Oregon, Eugene, OR, United States
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82
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Li C, Yu SSB. Rab proteins as regulators of lipid droplet formation and lipolysis. Cell Biol Int 2016; 40:1026-32. [PMID: 27453349 DOI: 10.1002/cbin.10650] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Accepted: 07/22/2016] [Indexed: 12/11/2022]
Abstract
Lipid droplets (LDs) are highly dynamic organelles that not only store neutral lipids but also are involved in multiple cellular processes. Dysregulation of lipogenesis or lipolysis greatly contributes to the pathogenesis of several human diseases, including obesity, diabetes, and fatty liver disease. Rab proteins have been found to be associated with LDs in proteomic studies and are also known to extensively regulate intracellular membrane traffic, suggesting that LDs actively communicate with other membrane compartments to maintain energy homeostasis. This review discusses recent studies that provide mechanistic insights into the regulation of LD formation and catabolism by Rab proteins in mammalian cells.
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Affiliation(s)
- Chunman Li
- School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, NT, Hong Kong SAR, China
| | - Sidney S B Yu
- School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, NT, Hong Kong SAR, China. .,Epithelial Cell Biology Research Centre, The Chinese University of Hong Kong, Shatin, NT, Hong Kong SAR, China.
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83
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Dluzen DF, Noren Hooten N, Evans MK. Extracellular RNA in aging. WILEY INTERDISCIPLINARY REVIEWS-RNA 2016; 8. [PMID: 27531497 DOI: 10.1002/wrna.1385] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Revised: 07/07/2016] [Accepted: 07/09/2016] [Indexed: 12/16/2022]
Abstract
Since the discovery of extracellular RNA (exRNA) in circulation and other bodily fluids, there has been considerable effort to catalog and assess whether exRNAs can be used as markers for health and disease. A variety of exRNA species have been identified including messenger RNA and noncoding RNA such as microRNA (miRNA), small nucleolar RNA, transfer RNA, and long noncoding RNA. Age-related changes in exRNA abundance have been observed, and it is likely that some of these transcripts play a role in aging. In this review, we summarize the current state of exRNA profiling in various body fluids and discuss age-related changes in exRNA abundance that have been identified in humans and other model organisms. miRNAs, in particular, are a major focus of current research and we will highlight and discuss the potential role that specific miRNAs might play in age-related phenotypes and disease. We will also review challenges facing this emerging field and various strategies that can be used for the validation and future use of exRNAs as markers of aging and age-related disease. WIREs RNA 2017, 8:e1385. doi: 10.1002/wrna.1385 For further resources related to this article, please visit the WIREs website.
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Affiliation(s)
- Douglas F Dluzen
- Laboratory of Epidemiology and Population Sciences, National Institute on Aging, National Institutes of Health, Baltimore, MD, USA
| | - Nicole Noren Hooten
- Laboratory of Epidemiology and Population Sciences, National Institute on Aging, National Institutes of Health, Baltimore, MD, USA
| | - Michele K Evans
- Laboratory of Epidemiology and Population Sciences, National Institute on Aging, National Institutes of Health, Baltimore, MD, USA
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84
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Sidjanin DJ, Park AK, Ronchetti A, Martins J, Jackson WT. TBC1D20 mediates autophagy as a key regulator of autophagosome maturation. Autophagy 2016; 12:1759-1775. [PMID: 27487390 DOI: 10.1080/15548627.2016.1199300] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
In humans, loss of TBC1D20 (TBC1 domain family, member 20) protein function causes Warburg Micro syndrome 4 (WARBM4), an autosomal recessive disorder characterized by congenital eye, brain, and genital abnormalities. TBC1D20-deficient mice exhibit ocular abnormalities and male infertility. TBC1D20 is a ubiquitously expressed member of the family of GTPase-activating proteins (GAPs) that increase the intrinsically slow GTP-hydrolysis rate of small RAB-GTPases when bound to GTP. Biochemical studies have established TBC1D20 as a GAP for RAB1B and RAB2A. However, the cellular role of TBC1D20 still remains elusive, and there is little information about how the functional loss of TBC1D20 causes clinical manifestations in WARBM4-affected children. Here we evaluate the role of TBC1D20 in cells carrying a null mutant allele, as well as TBC1D20-deficient mice, which display eye and testicular abnormalities. We demonstrate that TBC1D20, via its RAB1B GAP function, is a key regulator of autophagosome maturation, a process required for maintenance of autophagic flux and degradation of autophagic cargo. Our results provide evidence that TBC1D20-mediated autophagosome maturation maintains lens transparency by mediating the removal of damaged proteins and organelles from lens fiber cells. Additionally, our results show that in the testes TBC1D20-mediated maturation of autophagosomes is required for autophagic flux, but is also required for the formation of acrosomes. Furthermore TBC1D20-deficient mice, while not mimicking severe developmental brain abnormalities identified in WARBM4 affected children, display disrupted neuronal autophagic flux resulting in adult-onset motor dysfunction. In summary, we show that TBC1D20 has an essential role in the maturation of autophagosomes and a defect in TBC1D20 function results in eye, testicular, and neuronal abnormalities in mice implicating disrupted autophagy as a mechanism that contributes to WARBM4 pathogenesis.
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Affiliation(s)
- D J Sidjanin
- a Department of Cell Biology, Neurobiology, and Anatomy , Human and Molecular Genetics Center, Medical College of Wisconsin , Milwaukee , WI , USA
| | - Anna K Park
- a Department of Cell Biology, Neurobiology, and Anatomy , Human and Molecular Genetics Center, Medical College of Wisconsin , Milwaukee , WI , USA
| | - Adam Ronchetti
- a Department of Cell Biology, Neurobiology, and Anatomy , Human and Molecular Genetics Center, Medical College of Wisconsin , Milwaukee , WI , USA
| | - Jamaria Martins
- b Microbiology and Molecular Genetics, Human and Molecular Genetics Center, Medical College of Wisconsin , Milwaukee , WI , USA
| | - William T Jackson
- c Department of Microbiology and Immunology , University of Maryland School of Medicine , Baltimore , MD , USA
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85
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Rab23 activities and human cancer—emerging connections and mechanisms. Tumour Biol 2016; 37:12959-12967. [DOI: 10.1007/s13277-016-5207-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2016] [Accepted: 07/13/2016] [Indexed: 12/19/2022] Open
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86
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Trkova M, Hynek M, Dudakova L, Becvarova V, Hlozanek M, Raskova D, Vincent AL, Liskova P. Early detection of bilateral cataracts in utero may represent a manifestation of severe congenital disease. Am J Med Genet A 2016; 170:1843-8. [DOI: 10.1002/ajmg.a.37685] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Accepted: 04/11/2016] [Indexed: 11/10/2022]
Affiliation(s)
- Marie Trkova
- Gennet; Centre for Fetal Medicine and Reproductive Genetics; Prague Czech Republic
| | - Martin Hynek
- Gennet; Centre for Fetal Medicine and Reproductive Genetics; Prague Czech Republic
- Department of Gynecology and Obstetrics; Thomayer Hospital; Prague Czech Republic
| | - Lubica Dudakova
- Institute of Inherited Metabolic Diseases; First Faculty of Medicine; Charles University in Prague and General University Hospital in Prague; Czech Republic
| | - Vera Becvarova
- Gennet; Centre for Fetal Medicine and Reproductive Genetics; Prague Czech Republic
| | - Martin Hlozanek
- Department of Ophthalmology; Second Faculty of Medicine; Charles University in Prague and Motol Hospital in Prague; Czech Republic
| | - Dagmar Raskova
- Gennet; Centre for Fetal Medicine and Reproductive Genetics; Prague Czech Republic
| | - Andrea L. Vincent
- Faculty of Medical and Health Sciences; Department of Ophthalmology; New Zealand National Eye Centre; University of Auckland; Auckland New Zealand
| | - Petra Liskova
- Institute of Inherited Metabolic Diseases; First Faculty of Medicine; Charles University in Prague and General University Hospital in Prague; Czech Republic
- Department of Ophthalmology; First Faculty of Medicine; Charles University in Prague and General University Hospital in Prague; Prague Czech Republic
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87
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Abstract
Warburg syndrome is a rare disorder characterized by microcephaly, microcornea, congenital cataract, developmental delay, and hypogonadism. Here, we report two siblings from India who presented with developmental delay, microcornea, microphthalmia, and bilateral congenital cataracts, born to the third-degree consanguineously married couple. Both children had hypoplasia of corpus callosum. In this report, we aim to highlight and compare clinical features of these two cases with previously reported cases.
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Affiliation(s)
- Prabhjot Kaur Sekhon
- Department of Pediatrics, Bangalore Medical College and Research Institute, Bengaluru, Karnataka, India
| | - R Premalatha
- Department of Pediatrics, Bangalore Medical College and Research Institute, Bengaluru, Karnataka, India
| | - Sarala Sabapathy
- Department of Pediatrics, Bangalore Medical College and Research Institute, Bengaluru, Karnataka, India
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88
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Abdelhedi F, El Khattabi L, Essid N, Viot G, Letessier D, Lebbar A, Dupont JM. A de novo 10p11.23-p12.1 deletion recapitulates the phenotype observed in WAC mutations and strengthens the role of WAC in intellectual disability and behavior disorders. Am J Med Genet A 2016; 170:1912-7. [PMID: 27119754 DOI: 10.1002/ajmg.a.37686] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Accepted: 04/11/2016] [Indexed: 12/19/2022]
Abstract
Chromosomal microarray analysis has become a powerful diagnostic tool in the investigation of patients with intellectual disability leading to the discovery of dosage sensitive genes implicated in the manifestation of various genomic disorders. Interstitial deletions of the short arm of chromosome 10 represent rare genetic abnormalities, especially those encompassing the chromosomal region 10p11-p12. To date, only 10 postnatal cases with microdeletion of this region have been described, and all patients shared a common phenotype, including intellectual disability, abnormal behavior, distinct dysmorphic features, visual impairment, and cardiac malformations. WAC was suggested to be the main candidate gene for intellectual disability associated with 10 p11-p12 deletion syndrome. Here, we describe a new case of de novo 10p11.23-p12.1 microdeletion in a patient with intellectual disability, abnormal behavior, and distinct dysmorphic features. Our observation allows us to redefine the smallest region of overlap among patients reported so far, with a size of 80 Kb and which contains only the WAC gene. These findings strengthen the hypothesis that haploinsufficency of WAC gene might be likely responsible for intellectual disability and behavior disorders. Our data also led us to propose a clinical pathway for patients with this recognizable genetic syndrome depending on the facial dysmorphisms. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Fatma Abdelhedi
- Cytogenetics Laboratory, APHP, Cochin Hospital, Paris, France
| | - Laila El Khattabi
- Cytogenetics Laboratory, APHP, Cochin Hospital, Paris, France.,Paris Descartes University, Faculty of Medicine, Paris, France
| | - Nouha Essid
- Paediatric Neurology Unit, Department of Paediatric, Raymond Poincare Hospital, APHP, University of Versailles-St-Quentin, Versailles-St-Quentin, France
| | - Geraldine Viot
- Paris Descartes University, Faculty of Medicine, Paris, France.,Department of Gynecology-Obstetrics APHP, Cochin Hospital, Paris, France
| | | | - Aziza Lebbar
- Cytogenetics Laboratory, APHP, Cochin Hospital, Paris, France.,Paris Descartes University, Faculty of Medicine, Paris, France
| | - Jean-Michel Dupont
- Cytogenetics Laboratory, APHP, Cochin Hospital, Paris, France.,Paris Descartes University, Faculty of Medicine, Paris, France
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89
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Mhlanga-Mutangadura T, Johnson GS, Ashwini A, Shelton GD, Wennogle SA, Johnson GC, Kuroki K, O'Brien DP. A Homozygous RAB3GAP1:c.743delC Mutation in Rottweilers with Neuronal Vacuolation and Spinocerebellar Degeneration. J Vet Intern Med 2016; 30:813-8. [PMID: 26968732 PMCID: PMC4913561 DOI: 10.1111/jvim.13921] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Revised: 12/28/2015] [Accepted: 02/11/2016] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND A variety of presumed hereditary, neurologic diseases have been reported in young Rottweilers. Overlapping ages of onset and clinical signs have made antemortem diagnosis difficult. One of these diseases, neuronal vacuolation and spinocerebellar degeneration (NVSD) shares clinical and histological features with polyneuropathy with ocular abnormalities and neuronal vacuolation (POANV), a recently described hereditary disease in Black Russian Terriers (BRTs). Dogs with POANV harbor mutations in RAB3GAP1 which codes for a protein involved in membrane trafficking. HYPOTHESIS Rottweilers with NVSD will be homozygous for the RAB3GAP1:c.743delC allele associated with POANV in BRTs. ANIMALS Eight Rottweilers with NVSD confirmed at necropsy, 128 Rottweilers without early onset neurologic signs, and 468 randomly selected dogs from 169 other breeds. METHODS Retrospective case-control study. Dogs were genotyped for the RAB3GAP1:c.743delC allele with an allelic discrimination assay. RESULTS All 8 NVSD-affected dogs were homozygous for the RAB3GAP1:c.743delC allele while the 128 NVSD-free Rottweilers were either homozygous for the reference allele (n = 105) or heterozygous (n = 23) and the 468 genotyped dogs from other breeds were all homozygous for the reference allele. CONCLUSIONS AND CLINICAL IMPORTANCE The RAB3GAP1:c.743delC mutation is associated with a similar phenotype in Rottweilers and BRTs. Identification of the mutation permits a DNA test that can aid in the diagnosis of NVSD and identify carriers of the trait so that breeders can avoid producing affected dogs. Disruption of membrane trafficking could explain the neuronal vacuolation seen in NVSD and other spongiform encephalopathies.
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Affiliation(s)
- T Mhlanga-Mutangadura
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, MO
| | - G S Johnson
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, MO
| | - A Ashwini
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, MO
| | - G D Shelton
- Department of Pathology, University of California San Diego, La Jolla, CA
| | - S A Wennogle
- Department of Clinical Sciences, Colorado State University, Fort Collins, CO
| | - G C Johnson
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, MO
| | - K Kuroki
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, MO
| | - D P O'Brien
- Department of Veterinary Medicine and Surgery, College of Veterinary Medicine, University of Missouri, Columbia, MO
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90
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Handley MT, Carpanini SM, Mali GR, Sidjanin DJ, Aligianis IA, Jackson IJ, FitzPatrick DR. Warburg Micro syndrome is caused by RAB18 deficiency or dysregulation. Open Biol 2016; 5:150047. [PMID: 26063829 PMCID: PMC4632505 DOI: 10.1098/rsob.150047] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
RAB18, RAB3GAP1, RAB3GAP2 and TBC1D20 are each mutated in Warburg Micro syndrome, a rare autosomal recessive multisystem disorder. RAB3GAP1 and RAB3GAP2 form a binary ‘RAB3GAP’ complex that functions as a guanine-nucleotide exchange factor (GEF) for RAB18, whereas TBC1D20 shows modest RAB18 GTPase-activating (GAP) activity in vitro. Here, we show that in the absence of functional RAB3GAP or TBC1D20, the level, localization and dynamics of cellular RAB18 is altered. In cell lines where TBC1D20 is absent from the endoplasmic reticulum (ER), RAB18 becomes more stably ER-associated and less cytosolic than in control cells. These data suggest that RAB18 is a physiological substrate of TBC1D20 and contribute to a model in which a Rab-GAP can be essential for the activity of a target Rab. Together with previous reports, this indicates that Warburg Micro syndrome can be caused directly by loss of RAB18, or indirectly through loss of RAB18 regulators RAB3GAP or TBC1D20.
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Affiliation(s)
- Mark T Handley
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XU, UK
| | - Sarah M Carpanini
- Division of Neurobiology, The Roslin Institute and R(D)SVS, University of Edinburgh, Easter Bush, Midlothian EH25 9RG, UK
| | - Girish R Mali
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XU, UK
| | - Duska J Sidjanin
- Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Irene A Aligianis
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XU, UK
| | - Ian J Jackson
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XU, UK
| | - David R FitzPatrick
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XU, UK
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91
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Srivastava P, Saxena D, Joshi S, Phadke SR. Consanguinity as an Adjunct Diagnostic Tool. Indian J Pediatr 2016; 83:258-60. [PMID: 26138576 DOI: 10.1007/s12098-015-1764-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Accepted: 04/02/2015] [Indexed: 10/23/2022]
Abstract
History of consanguinity is important in monogenic disorders as it supports autosomal recessive mode of inheritance. This case report illustrates the use of homozygosity mapping using single nucleotide polymorphism (SNP) microarray data to identify the causative gene in a case with Warburg Micro syndrome (WARBM). This syndrome has non-specific features like microcephaly and cataract; etiological diagnosis based on clinical features is not possible. Four causative genes are known for WARBM syndrome. In such a situation of autosomal recessive disorders of heterogeneous etiologies, SNP microarray and homozygosity mapping is a useful and cost effective strategy.
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Affiliation(s)
- Priyanka Srivastava
- Department of Medical Genetics, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Raebareli Road, Lucknow, 226014, Uttar Pradesh, India
| | - Deepti Saxena
- Department of Medical Genetics, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Raebareli Road, Lucknow, 226014, Uttar Pradesh, India
| | - Stephen Joshi
- Department of Medical Genetics, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Raebareli Road, Lucknow, 226014, Uttar Pradesh, India
| | - Shubha R Phadke
- Department of Medical Genetics, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Raebareli Road, Lucknow, 226014, Uttar Pradesh, India.
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92
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Novel RAB3GAP1 compound heterozygous mutations in Japanese siblings with Warburg Micro syndrome. Brain Dev 2016; 38:337-40. [PMID: 26421802 DOI: 10.1016/j.braindev.2015.09.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Revised: 09/11/2015] [Accepted: 09/12/2015] [Indexed: 11/22/2022]
Abstract
BACKGROUND Warburg Micro syndrome (WARBM) is a rare autosomal recessive disease characterized by postnatal growth retardation, microcephaly, severely delayed motor and intellectual development, microcornea, congenital cataracts, optic atrophy, and hypogonadism. While WARBM is a genetically heterogeneous condition, RAB3GAP1 mutations account for ∼40% of WARBM patients, and 69 different mutations of various types (nonsense, missense, frameshift, and splice site mutations) have been identified to date. PATIENTS Japanese siblings (a 7 years 3 months old male and a 2 years 1month old female) were found to have WARBM-compatible phenotypes. Direct sequencing of RAB3GAP1 revealed novel compound heterozygous mutations in the siblings: a paternally inherited missense mutation (c.560G>C; p.Arg187Pro) in exon 7 and a maternally derived nonsense mutation (c.1009C>T; p.Arg337Ter) in exon 12. CONCLUSION The siblings had WARBM caused by novel mutations in RAB3GAP1. Since molecular diagnosis permits adequate genetic counseling and appropriate management for predicted complications such as adequate sex steroid supplementation therapy for hypogonadism, in addition to standard supportive therapies for developmental delay and visual dysfunction, we recommend molecular studies for this rare condition.
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93
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Wu Q, Sun X, Yue W, Lu T, Ruan Y, Chen T, Zhang D. RAB18, a protein associated with Warburg Micro syndrome, controls neuronal migration in the developing cerebral cortex. Mol Brain 2016; 9:19. [PMID: 26879639 PMCID: PMC4754921 DOI: 10.1186/s13041-016-0198-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Accepted: 02/08/2016] [Indexed: 01/23/2023] Open
Abstract
Background Loss of function mutations in RAB18, has been identified in patients with the human neurological and developmental disorder Warburg Micro syndrome. However, the function of RAB18 in brain remains unknown. Results In this study, we report that RAB18 is a critical regulator of neuronal migration and morphogenesis. Using in utero electroporation suppression of RAB18 in the mouse brain impairs radial migration. Overexpression of dominant negative RAB18 or disruption of RAB3GAP (RAB18GEF) also results in delayed neuronal migration in the developing mouse cortex and inhibition of neurite growth in vitro. Moreover, loss of RAB18 induces an acceleration of N-cadherin degradation by lysosomal pathway resulting in the decrease of surface level of N-cadherin on neurons. Conclusions RAB18 regulates neuronal migration and morphogenesis during development. Our findings highlight the critical role of RAB3GAP-RAB18 pathway in the developing cerebral cortex and might explain some of clinical features observed in patients with Warburg Micro syndrome. Electronic supplementary material The online version of this article (doi:10.1186/s13041-016-0198-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Qinwei Wu
- Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China. .,Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, 100871, China. .,Peking University Sixth Hospital/Institute of Mental Health, Beijing, 100191, China.
| | - Xiaqin Sun
- Peking University Sixth Hospital/Institute of Mental Health, Beijing, 100191, China. .,National Clinical Research Center for Mental Disorders/Key Laboratory for Mental Health, Ministry of Health (Peking University), Beijing, 100191, China.
| | - Weihua Yue
- Peking University Sixth Hospital/Institute of Mental Health, Beijing, 100191, China. .,National Clinical Research Center for Mental Disorders/Key Laboratory for Mental Health, Ministry of Health (Peking University), Beijing, 100191, China.
| | - Tianlan Lu
- Peking University Sixth Hospital/Institute of Mental Health, Beijing, 100191, China. .,National Clinical Research Center for Mental Disorders/Key Laboratory for Mental Health, Ministry of Health (Peking University), Beijing, 100191, China.
| | - Yanyan Ruan
- Peking University Sixth Hospital/Institute of Mental Health, Beijing, 100191, China. .,National Clinical Research Center for Mental Disorders/Key Laboratory for Mental Health, Ministry of Health (Peking University), Beijing, 100191, China.
| | - Tianda Chen
- Peking University Sixth Hospital/Institute of Mental Health, Beijing, 100191, China. .,National Clinical Research Center for Mental Disorders/Key Laboratory for Mental Health, Ministry of Health (Peking University), Beijing, 100191, China.
| | - Dai Zhang
- Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China. .,Peking University Sixth Hospital/Institute of Mental Health, Beijing, 100191, China. .,National Clinical Research Center for Mental Disorders/Key Laboratory for Mental Health, Ministry of Health (Peking University), Beijing, 100191, China. .,PKU-IDG/McGovern Institute for Brain Research, Peking University, Beijing, 100871, China.
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94
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Strain-Specific Altered Regulatory Response of Rab7a and Tau in Creutzfeldt-Jakob Disease and Alzheimer's Disease. Mol Neurobiol 2016; 54:697-709. [PMID: 26768426 DOI: 10.1007/s12035-016-9694-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Accepted: 01/05/2016] [Indexed: 09/29/2022]
Abstract
There is an increasing demand for the understanding of pathophysiology on neurodegeneration diseases at early stages. Changes in endocytic machinery and the cytoskeleton-associated response are the first alterations observed in Creutzfeldt-Jakob disease (CJD) and Alzheimer's disease AD brain. In this study, we performed a targeted search for endocytic pathway proteins in the different regions of the brain. We found late endosome marker Rab7a which was significantly upregulated in the frontal cortex region in the rapid progressive CJD form (MM1) and rapid progressive AD (rpAD) forms. However, Rab9 expression was significantly downregulated only in CJD-MM1 brain frontal cortex region. In the cerebellum, Rab7a expression showed significant upregulation in both subtype MM1 and VV2 CJD forms, in contrast to Rab9 which showed significant downregulation in both subtype MM1 and VV2 CJD forms at terminal stage of the disease. To check regulatory response at pre-symptomatic stage of the disease, we checked the regulatory interactive response of Rab7a, Rab9, and known biomarkers PrPC and tau forms in frontal cortex at pre-symptomatic stage of the disease in tg340 mice expressing about fourfold of human PrP-M129 with PrP-null background that had been inoculated with human sCJD MM1 brain tissue homogenates (sCJD MM1 mice). In addition, we analyzed 5XFAD mice, exhibiting five mutations in the APP and presenilin genes related to familial Alzheimer's disease (FAD), to validate specific regulatory response of Rab7a, Rab9, tau, and phosphorylated form of tau by immunostaining 5XFAD mice in comparison with the wild-type age-matched mice brain. The cortical region of 5XFAD mice brain showed accumulated form of Rab7a in puncta that co-label for p-Tau, indicating colocalization by using confocal laser-scanning microscopy and was confirmed by using reverse co-immunoprecipitation. Furthermore, synthetic RNA (siRNA) against the Rab7a gene decreased expression of Rab7a protein, in cortical primary neuronal cultures of PrPC wild type. This depleted expression of Rab7a led to the increased accumulation of PrPC in Rab9-positive endosomal compartments and consequently an increased co-localization between PrPC/Rab9; however, total tau level decreased. Interestingly, siRNA against tau gene in cortical primary neuronal cultures of PrPC wild-type mice showed enhanced Rab7a and Rab9 expression and increase formation of dendritic spines. The work described highlighted the selective involvement of late endosomal compartment marker Rab7a in CJD, slow and rapid progressive forms of AD pathogenesis.
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95
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Small GTPases in peroxisome dynamics. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2016; 1863:1006-13. [PMID: 26775587 DOI: 10.1016/j.bbamcr.2016.01.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Revised: 01/05/2016] [Accepted: 01/07/2016] [Indexed: 12/12/2022]
Abstract
In this review article, we summarize current knowledge on peroxisome biogenesis/functions and the role that small GTPases may play in these processes. Precise intracellular distribution of cell organelles requires their regulated association to microtubules and the actin cytoskeleton. In this respect, RhoGDP/RhoGTP favor binding of peroxisomes to microtubules and actin filaments. In its GTP-bound form, RhoA activates a regulatory cascade involving Rho kinaseII and non-muscle myosinIIA. Such interactions frequently depend on phosphoinositides (PIs) of which PI4P, PI(4,5)P2, and PI(3,5)P2 were found to be present in the peroxisomal membrane. PIs are pivotal determinants of intracellular signaling and known to regulate a wide range of cellular functions. In many of these functions, small GTPases are implicated. The small GTPase ADP-ribosylation factor 1 (Arf1), for example, is known to stimulate synthesis of PI4P and PI(4,5)P2 on the Golgi to regulate protein and lipid sorting. In vitro binding assays localized Arf1 and the COPI complex to peroxisomes. In light of the recent discussion of pre-peroxisomal vesicle generation at the ER, peroxisomal Arf1-COPI vesicles may serve retrograde transport of ER-resident components. A mass spectrometric screen localized various Rab proteins to peroxisomes. Overexpression of these proteins in combination with laser-scanning fluorescence microscopy co-localized Rab6, Rab8, Rab10, Rab14, and Rab18 with peroxisomal structures. By analogy to the role these proteins play in other organelle dynamics, we may envisage what the function of these proteins may be in relation to the peroxisomal compartment.
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96
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SanCristobal M, Rohart F, Lascor C, Bouffaud M, Trouilh L, Martin PGP, Lippi Y, Tribout T, Faraut T, Mercat MJ, Milan D, Liaubet L. Exploring transcriptomic diversity in muscle revealed that cellular signaling pathways mainly differentiate five Western porcine breeds. BMC Genomics 2015; 16:1055. [PMID: 26651482 PMCID: PMC4676870 DOI: 10.1186/s12864-015-2259-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Accepted: 11/30/2015] [Indexed: 12/23/2022] Open
Abstract
Background Among transcriptomic studies, those comparing species or populations can increase our understanding of the impact of the evolutionary forces on the differentiation of populations. A particular situation is the one of short evolution time with breeds of a domesticated species that underwent strong selective pressures. In this study, the gene expression diversity across five pig breeds has been explored in muscle. Samples came from: 24 Duroc, 33 Landrace, 41 Large White dam line, 10 Large White sire line and 39 Piétrain. From these animals, 147 muscle samples obtained at slaughter were analyzed using the porcine Agilent 44 K v1 microarray. Results A total of 12,358 genes were identified as expressed in muscle after normalization and 1,703 genes were declared differential for at least one breed (FDR < 0.001). The functional analysis highlighted that gene expression diversity is mainly linked to cellular signaling pathways such as the PI3K (phosphoinositide 3-kinase) pathway. The PI3K pathway is known to be involved in the control of development of the skeletal muscle mass by affecting extracellular matrix - receptor interactions, regulation of actin cytoskeleton pathways and some metabolic functions. This study also highlighted 228 spots (171 unique genes) that differentiate the breeds from each other. A common subgroup of 15 genes selected by three statistical methods was able to differentiate Duroc, Large White and Piétrain breeds. Conclusions This study on transcriptomic differentiation across Western pig breeds highlighted a global picture: mainly signaling pathways were affected. This result is consistent with the selection objective of increasing muscle mass. These transcriptional changes may indicate selection pressure or simply breed differences which may be driven by human selection. Further work aiming at comparing genetic and transcriptomic diversities would further increase our understanding of the consequences of human impact on livestock species. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-2259-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Magali SanCristobal
- INRA, UMR1388 Génétique, Physiologie et Systèmes d'Elevage, F-31326, Castanet-Tolosan, France. .,Physiologie et Systèmes d'Elevage, Université de Toulouse INPT ENSAT, UMR1388 Génétique, F-31326, Castanet-Tolosan, France. .,Physiologie et Systèmes d'Elevage, Université de Toulouse INPT ENVT, UMR1388 Génétique, F-31076, Toulouse, France.
| | - Florian Rohart
- INRA, UMR1388 Génétique, Physiologie et Systèmes d'Elevage, F-31326, Castanet-Tolosan, France. .,Physiologie et Systèmes d'Elevage, Université de Toulouse INPT ENSAT, UMR1388 Génétique, F-31326, Castanet-Tolosan, France. .,Physiologie et Systèmes d'Elevage, Université de Toulouse INPT ENVT, UMR1388 Génétique, F-31076, Toulouse, France. .,Australian Institute for Bioengineering and Nanotechnology (AIBN), Corner College and Cooper Rds (Bldg 75), The University of Queensland, Brisbane Qld, 4072, Australia.
| | - Christine Lascor
- INRA, UMR1388 Génétique, Physiologie et Systèmes d'Elevage, F-31326, Castanet-Tolosan, France. .,Physiologie et Systèmes d'Elevage, Université de Toulouse INPT ENSAT, UMR1388 Génétique, F-31326, Castanet-Tolosan, France. .,Physiologie et Systèmes d'Elevage, Université de Toulouse INPT ENVT, UMR1388 Génétique, F-31076, Toulouse, France.
| | | | - Lidwine Trouilh
- Plateforme Transcriptome GeT-Biopuces, Laboratoire d'Ingénierie des Systèmes Biologiques et des Procédés (LISBP), F-31077, Toulouse, France.
| | - Pascal G P Martin
- Plateau Transcriptomic impact of Xenobiotics (TRiX), ToxAlim INRA/INP, F-31027, Toulouse, France.
| | - Yannick Lippi
- Plateau Transcriptomic impact of Xenobiotics (TRiX), ToxAlim INRA/INP, F-31027, Toulouse, France.
| | | | - Thomas Faraut
- INRA, UMR1388 Génétique, Physiologie et Systèmes d'Elevage, F-31326, Castanet-Tolosan, France. .,Physiologie et Systèmes d'Elevage, Université de Toulouse INPT ENSAT, UMR1388 Génétique, F-31326, Castanet-Tolosan, France. .,Physiologie et Systèmes d'Elevage, Université de Toulouse INPT ENVT, UMR1388 Génétique, F-31076, Toulouse, France.
| | | | - Denis Milan
- INRA, UMR1388 Génétique, Physiologie et Systèmes d'Elevage, F-31326, Castanet-Tolosan, France. .,Physiologie et Systèmes d'Elevage, Université de Toulouse INPT ENSAT, UMR1388 Génétique, F-31326, Castanet-Tolosan, France. .,Physiologie et Systèmes d'Elevage, Université de Toulouse INPT ENVT, UMR1388 Génétique, F-31076, Toulouse, France.
| | - Laurence Liaubet
- INRA, UMR1388 Génétique, Physiologie et Systèmes d'Elevage, F-31326, Castanet-Tolosan, France. .,Physiologie et Systèmes d'Elevage, Université de Toulouse INPT ENSAT, UMR1388 Génétique, F-31326, Castanet-Tolosan, France. .,Physiologie et Systèmes d'Elevage, Université de Toulouse INPT ENVT, UMR1388 Génétique, F-31076, Toulouse, France.
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Mhlanga-Mutangadura T, Johnson GS, Schnabel RD, Taylor JF, Johnson GC, Katz ML, Shelton GD, Lever TE, Giuliano E, Granger N, Shomper J, O'Brien DP. A mutation in the Warburg syndrome gene, RAB3GAP1, causes a similar syndrome with polyneuropathy and neuronal vacuolation in Black Russian Terrier dogs. Neurobiol Dis 2015; 86:75-85. [PMID: 26607784 DOI: 10.1016/j.nbd.2015.11.016] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2015] [Revised: 11/13/2015] [Accepted: 11/18/2015] [Indexed: 11/30/2022] Open
Abstract
An autosomal recessive disease of Black Russian Terriers was previously described as a juvenile-onset, laryngeal paralysis and polyneuropathy similar to Charcot Marie Tooth disease in humans. We found that in addition to an axonal neuropathy, affected dogs exhibit microphthalmia, cataracts, and miotic pupils. On histopathology, affected dogs exhibit a spongiform encephalopathy characterized by accumulations of abnormal, membrane-bound vacuoles of various sizes in neuronal cell bodies, axons and adrenal cells. DNA from an individual dog with this polyneuropathy with ocular abnormalities and neuronal vacuolation (POANV) was used to generate a whole genome sequence which contained a homozygous RAB3GAP1:c.743delC mutation that was absent from 73 control canine whole genome sequences. An additional 12 Black Russian Terriers with POANV were RAB3GAP1:c.743delC homozygotes. DNA samples from 249 Black Russian Terriers with no known signs of POANV were either heterozygotes or homozygous for the reference allele. Mutations in human RAB3GAP1 cause Warburg micro syndrome (WARBM), a severe developmental disorder characterized by abnormalities of the eye, genitals and nervous system including a predominantly axonal peripheral neuropathy. RAB3GAP1 encodes the catalytic subunit of a GTPase activator protein and guanine exchange factor for Rab3 and Rab18 respectively. Rab proteins are involved in membrane trafficking in the endoplasmic reticulum, axonal transport, autophagy and synaptic transmission. The neuronal vacuolation and membranous inclusions and vacuoles in axons seen in this canine disorder likely reflect alterations of these processes. Thus, this canine disease could serve as a model for WARBM and provide insight into its pathogenesis and treatment.
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Affiliation(s)
| | - Gary S Johnson
- Department of Veterinary Pathobiology, University of Missouri, Columbia, USA
| | - Robert D Schnabel
- Division of Animal Sciences, University of Missouri, Columbia, USA; Informatics Institute, University of Missouri, Columbia, USA
| | - Jeremy F Taylor
- Division of Animal Sciences, University of Missouri, Columbia, USA
| | - Gayle C Johnson
- Department of Veterinary Pathobiology, University of Missouri, Columbia, USA
| | - Martin L Katz
- Mason Eye Institute, University of Missouri, Columbia, USA
| | - G Diane Shelton
- Department of Pathology, University of California, San Diego, La Jolla, USA
| | - Teresa E Lever
- Department of Otolaryngology, University of Missouri, Columbia, USA
| | - Elizabeth Giuliano
- Department of Veterinary Medicine & Surgery, University of Missouri, Columbia, USA
| | - Nicolas Granger
- School of Veterinary Sciences, University of Bristol, Langford House, Langford, Somerset BS40 5DU, UK
| | - Jeremy Shomper
- Department of Veterinary Medicine & Surgery, University of Missouri, Columbia, USA
| | - Dennis P O'Brien
- Department of Veterinary Medicine & Surgery, University of Missouri, Columbia, USA.
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98
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Dunst S, Kazimiers T, von Zadow F, Jambor H, Sagner A, Brankatschk B, Mahmoud A, Spannl S, Tomancak P, Eaton S, Brankatschk M. Endogenously tagged rab proteins: a resource to study membrane trafficking in Drosophila. Dev Cell 2015; 33:351-65. [PMID: 25942626 PMCID: PMC4431667 DOI: 10.1016/j.devcel.2015.03.022] [Citation(s) in RCA: 108] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Revised: 01/21/2015] [Accepted: 03/29/2015] [Indexed: 11/25/2022]
Abstract
Membrane trafficking is key to the cell biological mechanisms underlying development. Rab GTPases control specific membrane compartments, from core secretory and endocytic machinery to less-well-understood compartments. We tagged all 27 Drosophila Rabs with YFP(MYC) at their endogenous chromosomal loci, determined their expression and subcellular localization in six tissues comprising 23 cell types, and provide this data in an annotated, searchable image database. We demonstrate the utility of these lines for controlled knockdown and show that similar subcellular localization can predict redundant functions. We exploit this comprehensive resource to ask whether a common Rab compartment architecture underlies epithelial polarity. Strikingly, no single arrangement of Rabs characterizes the five epithelia we examine. Rather, epithelia flexibly polarize Rab distribution, producing membrane trafficking architectures that are tissue- and stage-specific. Thus, the core machinery responsible for epithelial polarization is unlikely to rely on polarized positioning of specific Rab compartments.
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Affiliation(s)
- Sebastian Dunst
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden 01307, Germany
| | - Tom Kazimiers
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden 01307, Germany; HHMI Janelia Research Campus, Ashburn, VA 20147, USA
| | - Felix von Zadow
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden 01307, Germany
| | - Helena Jambor
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden 01307, Germany
| | - Andreas Sagner
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden 01307, Germany; MRC National Institute for Medical Research, London NW7 1AA, UK
| | - Beate Brankatschk
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden 01307, Germany; Paul Langerhans Institute, Dresden 01307, Germany
| | - Ali Mahmoud
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden 01307, Germany
| | - Stephanie Spannl
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden 01307, Germany
| | - Pavel Tomancak
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden 01307, Germany.
| | - Suzanne Eaton
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden 01307, Germany.
| | - Marko Brankatschk
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden 01307, Germany.
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99
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Two novel homozygous RAB3GAP1 mutations cause Warburg micro syndrome. Hum Genome Var 2015; 2:15034. [PMID: 27081543 PMCID: PMC4785564 DOI: 10.1038/hgv.2015.34] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Revised: 08/07/2015] [Accepted: 08/11/2015] [Indexed: 11/30/2022] Open
Abstract
Warburg micro syndrome is an autosomal recessive disease where patients present with optic, neurologic and genital symptoms. Until now, four disease genes for Warburg micro syndrome, RAB3GAP1, RAB3GAP2, RAB18 and TBC1D20, have been identified. Here, we report two novel homozygous RAB3GAP1 mutations (c.22G>T, p.Glu8* and c.1353delA, p.Pro452Hisfs*5) in two consanguineous families by whole-exome sequencing.
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100
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Abstract
Rab GTPases control intracellular membrane traffic by recruiting specific effector proteins to restricted membranes in a GTP-dependent manner. In this Cell Science at a Glance and the accompanying poster, we highlight the regulation of Rab GTPases by proteins that control their membrane association and activation state, and provide an overview of the cellular processes that are regulated by Rab GTPases and their effectors, including protein sorting, vesicle motility and vesicle tethering. We also discuss the physiological importance of Rab GTPases and provide examples of diseases caused by their dysfunctions.
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Affiliation(s)
- Yan Zhen
- Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, Montebello, Oslo N-0379, Norway Department for Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, Montebello, Oslo N-0379, Norway
| | - Harald Stenmark
- Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, Montebello, Oslo N-0379, Norway Department for Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, Montebello, Oslo N-0379, Norway
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