1
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Liu RJY, Al-Molieh Y, Chen SZ, Drobac M, Urban D, Chen CH, Yao HHY, Geng RSQ, Li L, Pluthero FG, Benlekbir S, Rubinstein JL, Kahr WHA. The Sec1/Munc18 protein VPS33B forms a uniquely bidirectional complex with VPS16B. J Biol Chem 2023; 299:104718. [PMID: 37062417 DOI: 10.1016/j.jbc.2023.104718] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2023] [Revised: 03/03/2023] [Accepted: 04/07/2023] [Indexed: 04/18/2023] Open
Abstract
Loss of function variants of VPS33B and VIPAS39 (encoding VPS16B) are causative for arthrogryposis, renal dysfunction and cholestasis (ARC) syndrome, where early lethality of patients indicates that VPS33B and VPS16B play essential cellular roles. VPS33B is a member of the Sec1/Munc18 (SM) protein family, and thus thought to facilitate vesicular fusion via interaction with SNARE complexes, as does its paralog VPS33A in the homotypic fusion and vacuole sorting (HOPS) complex. VPS33B and VPS16B have been shown to associate, but little is known about the composition, structure or function of the VPS33B/VPS16B complex. We show here that human VPS33B/VPS16B is a high molecular weight complex, which we expressed in yeast to obtain material for structural, composition and stability analysis. Circular dichroism data indicate VPS33B/VPS16B has a well-folded α-helical secondary structure, for which size exclusion chromatography-multi angle light scattering revealed a MW of ∼315 kDa. Quantitative immunoblotting indicated the complex has a VPS33B:VPS16B ratio of 2:3. Expression of ARC syndrome-causing VPS33B missense variants showed that L30P disrupts complex formation, but not S243F or H344D. Truncated VPS16B containing amino acids 143-316 was sufficient to form a complex with VPS33B. Small angle X-ray scattering and negative staining electron microscopy revealed a two-lobed shape for VPS33B/VPS16B. Avidin tagging indicated that each lobe contains a VPS33B molecule, and they are oriented in opposite directions. From this we propose a structure for VPS33B/VPS16B that allows the copies of VPS33B at each end to interact with separate SNARE bundles and/or SNAREpins, plus their associated membrane components. Thus our observations reveal the only known potentially bidirectional SM protein complex.
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Affiliation(s)
- Richard J Y Liu
- Department of Biochemistry, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Yusef Al-Molieh
- Department of Biochemistry, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Shao Z Chen
- Department of Biochemistry, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Marko Drobac
- Department of Biochemistry, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Denisa Urban
- Department of Biochemistry, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Chang H Chen
- Department of Biochemistry, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Helen H Y Yao
- Department of Biochemistry, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Ryan S Q Geng
- Department of Biochemistry, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Ling Li
- Cell Biology Program, Research Institute, Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada
| | - Fred G Pluthero
- Cell Biology Program, Research Institute, Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada
| | - Samir Benlekbir
- Molecular Medicine Program, Research Institute, Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada
| | - John L Rubinstein
- Department of Biochemistry, University of Toronto, Toronto, ON, M5S 1A8, Canada; Molecular Medicine Program, Research Institute, Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada
| | - Walter H A Kahr
- Department of Biochemistry, University of Toronto, Toronto, ON, M5S 1A8, Canada; Cell Biology Program, Research Institute, Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada; Division of Haematology/Oncology, Department of Paediatrics, University of Toronto and The Hospital for Sick Children, Toronto, ON, M5G 1X8, Canada.
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2
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Overlapping Machinery in Lysosome-Related Organelle Trafficking: A Lesson from Rare Multisystem Disorders. Cells 2022; 11:cells11223702. [PMID: 36429129 PMCID: PMC9688865 DOI: 10.3390/cells11223702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 11/08/2022] [Accepted: 11/16/2022] [Indexed: 11/23/2022] Open
Abstract
Lysosome-related organelles (LROs) are a group of functionally diverse, cell type-specific compartments. LROs include melanosomes, alpha and dense granules, lytic granules, lamellar bodies and other compartments with distinct morphologies and functions allowing specialised and unique functions of their host cells. The formation, maturation and secretion of specific LROs are compromised in a number of hereditary rare multisystem disorders, including Hermansky-Pudlak syndromes, Griscelli syndrome and the Arthrogryposis, Renal dysfunction and Cholestasis syndrome. Each of these disorders impacts the function of several LROs, resulting in a variety of clinical features affecting systems such as immunity, neurophysiology and pigmentation. This has demonstrated the close relationship between LROs and led to the identification of conserved components required for LRO biogenesis and function. Here, we discuss aspects of this conserved machinery among LROs in relation to the heritable multisystem disorders they associate with, and present our current understanding of how dysfunctions in the proteins affected in the disease impact the formation, motility and ultimate secretion of LROs. Moreover, we have analysed the expression of the members of the CHEVI complex affected in Arthrogryposis, Renal dysfunction and Cholestasis syndrome, in different cell types, by collecting single cell RNA expression data from the human protein atlas. We propose a hypothesis describing how transcriptional regulation could constitute a mechanism that regulates the pleiotropic functions of proteins and their interacting partners in different LROs.
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3
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Mahanty S, Setty SRG. Epidermal Lamellar Body Biogenesis: Insight Into the Roles of Golgi and Lysosomes. Front Cell Dev Biol 2021; 9:701950. [PMID: 34458262 PMCID: PMC8387949 DOI: 10.3389/fcell.2021.701950] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Accepted: 07/09/2021] [Indexed: 12/25/2022] Open
Abstract
Epidermal lamellar bodies (eLBs) are secretory organelles that carry a wide variety of secretory cargo required for skin homeostasis. eLBs belong to the class of lysosome-related organelles (LROs), which are cell-type-specific organelles that perform diverse functions. The formation of eLBs is thought to be related to that of other LROs, which are formed either through the gradual maturation of Golgi/endosomal precursors or by the conversion of conventional lysosomes. Current evidence suggests that eLB biogenesis presumably initiate from trans-Golgi network and receive cargo from endosomes, and also acquire lysosome characteristics during maturation. These multistep biogenesis processes are frequently disrupted in human skin disorders. However, many gaps remain in our understanding of eLB biogenesis and their relationship to skin diseases. Here, we describe our current understanding on eLB biogenesis with a focus on cargo transport to this LRO and highlight key areas where future research is needed.
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Affiliation(s)
- Sarmistha Mahanty
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bengaluru, India
| | - Subba Rao Gangi Setty
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bengaluru, India
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4
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Mbiandjeu S, Balduini A, Malara A. Megakaryocyte Cytoskeletal Proteins in Platelet Biogenesis and Diseases. Thromb Haemost 2021; 122:666-678. [PMID: 34218430 DOI: 10.1055/s-0041-1731717] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Thrombopoiesis governs the formation of blood platelets in bone marrow by converting megakaryocytes into long, branched proplatelets on which individual platelets are assembled. The megakaryocyte cytoskeleton responds to multiple microenvironmental cues, including chemical and mechanical stimuli, sustaining the platelet shedding. During the megakaryocyte's life cycle, cytoskeletal networks organize cell shape and content, connect them physically and biochemically to the bone marrow vascular niche, and enable the release of platelets into the bloodstream. While the basic building blocks of the cytoskeleton have been studied extensively, new sets of cytoskeleton regulators have emerged as critical components of the dynamic protein network that supports platelet production. Understanding how the interaction of individual molecules of the cytoskeleton governs megakaryocyte behavior is essential to improve knowledge of platelet biogenesis and develop new therapeutic strategies for inherited thrombocytopenias caused by alterations in the cytoskeletal genes.
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Affiliation(s)
- Serge Mbiandjeu
- Department of Molecular Medicine, University of Pavia, Pavia, Italy
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5
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Schneeberger PE, Nampoothiri S, Holling T, Yesodharan D, Alawi M, Knisely AS, Müller T, Plecko B, Janecke AR, Kutsche K. Biallelic variants in VPS50 cause a neurodevelopmental disorder with neonatal cholestasis. Brain 2021; 144:3036-3049. [PMID: 34037727 DOI: 10.1093/brain/awab206] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 05/18/2021] [Accepted: 05/19/2021] [Indexed: 11/14/2022] Open
Abstract
Golgi-associated retrograde protein (GARP) and endosome-associated recycling protein (EARP) complexes are membrane-tethering heterotetramers located at the trans-Golgi network and recycling endosomes, respectively. GARP and EARP share the three subunits VPS51, VPS52, and VPS53, while VPS50 is unique to EARP and VPS54 to GARP. Retrograde transport of endosomal cargos to the TGN is mediated by GARP and endocytic recycling by EARP. Here we report two unrelated individuals with homozygous variants in VPS50, a splice variant (c.1978-1G>T) and an in-frame deletion (p.Thr608del). Both patients had severe developmental delay, postnatal microcephaly, corpus callosum hypoplasia, seizures and irritability, transient neonatal cholestasis, and failure to thrive. Light and transmission electron microscopy of liver from one revealed absence of gamma-glutamyltransferase at bile canaliculi, with mislocalization to basolateral membranes, and abnormal tight junctions. Using patient-derived fibroblasts, we identified reduced VPS50 protein accompanied by reduced levels of VPS52 and VPS53. While transferrin-receptor internalization rate was normal in cells of both patients, recycling of the receptor to the plasma membrane was significantly delayed. These data underscore the importance of VPS50 and/or the EARP complex in endocytic recycling and suggest an additional function in establishing cell polarity and trafficking between basolateral and apical membranes in hepatocytes. Individuals with biallelic hypomorphic variants in VPS50, VPS51 or VPS53 show an overarching neurodegenerative disorder with severe developmental delay, intellectual disability, microcephaly, early-onset epilepsy, and variable atrophy of the cerebellum, cerebrum, and/or brainstem. The term "GARP/EARP deficiency" designates disorders in such individuals.
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Affiliation(s)
- Pauline E Schneeberger
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Sheela Nampoothiri
- Department of Pediatric Genetics, Amrita Institute of Medical Sciences and Research Centre, Cochin 682041, Kerala, India
| | - Tess Holling
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Dhanya Yesodharan
- Department of Pediatric Genetics, Amrita Institute of Medical Sciences and Research Centre, Cochin 682041, Kerala, India
| | - Malik Alawi
- Bioinformatics Core, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - A S Knisely
- Institut für Pathologie, Medizinische Universität Graz, 8010 Graz, Austria
| | - Thomas Müller
- Department of Pediatrics I, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Barbara Plecko
- Department of Pediatrics, Division of General Pediatrics, Medical University of Graz, 8010 Graz, Austria
| | - Andreas R Janecke
- Department of Pediatrics I, Medical University of Innsbruck, 6020 Innsbruck, Austria.,Division of Human Genetics, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Kerstin Kutsche
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
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6
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Zhang J, Tracy C, Pasare C, Zeng J, Krämer H. Hypersensitivity of Vps33B mutant flies to non-pathogenic infections is dictated by aberrant activation of p38b MAP kinase. Traffic 2020; 21:578-589. [PMID: 32677257 DOI: 10.1111/tra.12756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2020] [Revised: 07/10/2020] [Accepted: 07/12/2020] [Indexed: 11/29/2022]
Abstract
Loss of the arthrogryposis-renal dysfunction-cholestasis (ARC) syndrome-linked Vps33B protein results in exaggerated inflammatory responses upon activation of receptors of the innate immune system in both vertebrates and flies. However, little is known about the signaling elements downstream of these receptors that are critical for the hypersensitivity of Vps33B mutants. Here, we show that p38b MAP kinase contributes to the enhanced inflammatory responses in flies lacking Vps33B. Loss of p38b mitogen-activated protein kinase (MAPK) reduces enhanced inflammatory responses and prolongs the survival of infected Vps33B deficient flies. The function of p38 MAPK is not limited to its proinflammatory effects downstream of the PGRP-LC receptor as p38 also modulates endosomal trafficking of PGRP-LC and phagocytosis of bacteria. Expression of constitutively active p38b MAPK, but not dominant negative p38b MAPK enhances accumulation of endocytosed PGRP-LC receptors or phagocytosed bacteria within cells. Moreover, p38 MAPK is required for induction of macropinocytosis, an alternate pathway for the downregulation of immune receptors. Together, our data indicate that p38 MAPK activates multiple pathways that can contribute to the dysregulation of innate immune signaling in ARC syndrome.
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Affiliation(s)
- Jian Zhang
- Department of Neuroscience, UT Southwestern Medical Center, Dallas, Texas, USA.,Department of Neurology, The First Affiliated Hospital, Sun Yat-sen University, Guangdong Provincial Key Laboratory for Diagnosis and Treatment of Major Neurological Diseases, National Key Clinical Department and Key Discipline of Neurology, Guangzhou, China
| | - Charles Tracy
- Department of Neuroscience, UT Southwestern Medical Center, Dallas, Texas, USA
| | - Chandrashekhar Pasare
- Division of Immunobiology and Center for Inflammation and Tolerance, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA.,Department of Pediatrics, University of Cincinnati, College of Medicine, Cincinnati, Ohio, USA
| | - Jinsheng Zeng
- Department of Neurology, The First Affiliated Hospital, Sun Yat-sen University, Guangdong Provincial Key Laboratory for Diagnosis and Treatment of Major Neurological Diseases, National Key Clinical Department and Key Discipline of Neurology, Guangzhou, China
| | - Helmut Krämer
- Department of Neuroscience, UT Southwestern Medical Center, Dallas, Texas, USA.,Department of Cell Biology, UT Southwestern Medical Center, Dallas, Texas, USA
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7
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van der Beek J, Jonker C, van der Welle R, Liv N, Klumperman J. CORVET, CHEVI and HOPS – multisubunit tethers of the endo-lysosomal system in health and disease. J Cell Sci 2019; 132:132/10/jcs189134. [DOI: 10.1242/jcs.189134] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
ABSTRACT
Multisubunit tethering complexes (MTCs) are multitasking hubs that form a link between membrane fusion, organelle motility and signaling. CORVET, CHEVI and HOPS are MTCs of the endo-lysosomal system. They regulate the major membrane flows required for endocytosis, lysosome biogenesis, autophagy and phagocytosis. In addition, individual subunits control complex-independent transport of specific cargoes and exert functions beyond tethering, such as attachment to microtubules and SNARE activation. Mutations in CHEVI subunits lead to arthrogryposis, renal dysfunction and cholestasis (ARC) syndrome, while defects in CORVET and, particularly, HOPS are associated with neurodegeneration, pigmentation disorders, liver malfunction and various forms of cancer. Diseases and phenotypes, however, vary per affected subunit and a concise overview of MTC protein function and associated human pathologies is currently lacking. Here, we provide an integrated overview on the cellular functions and pathological defects associated with CORVET, CHEVI or HOPS proteins, both with regard to their complexes and as individual subunits. The combination of these data provides novel insights into how mutations in endo-lysosomal proteins lead to human pathologies.
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Affiliation(s)
- Jan van der Beek
- Section Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, Institute for Biomembranes, Utrecht University, Utrecht 3584 CX, The Netherlands
| | - Caspar Jonker
- Section Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, Institute for Biomembranes, Utrecht University, Utrecht 3584 CX, The Netherlands
| | - Reini van der Welle
- Section Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, Institute for Biomembranes, Utrecht University, Utrecht 3584 CX, The Netherlands
| | - Nalan Liv
- Section Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, Institute for Biomembranes, Utrecht University, Utrecht 3584 CX, The Netherlands
| | - Judith Klumperman
- Section Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, Institute for Biomembranes, Utrecht University, Utrecht 3584 CX, The Netherlands
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8
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Wang C, Cheng Y, Zhang X, Li N, Zhang L, Wang S, Tong X, Xu Y, Chen GQ, Cheng S, Fan X, Liu J. Vacuolar Protein Sorting 33B Is a Tumor Suppressor in Hepatocarcinogenesis. Hepatology 2018; 68:2239-2253. [PMID: 29729199 DOI: 10.1002/hep.30077] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Accepted: 05/20/2018] [Indexed: 12/11/2022]
Abstract
Polarity defects are frequently involved in liver diseases, such as chronic hepatitis and hepatocellular carcinoma (HCC). It was reported that vacuolar protein sorting 33B (Vps33b) plays critical roles in the maintenance of hepatocyte polarity; however, the functional roles and mechanisms of Vps33b in HCC occurrence and progression remain unknown. First of all, we showed that Vps33b is down-regulated in human and mouse liver cancer samples, and the low expression levels of Vps33b correlate with the poor prognosis of many HCC patients. Liver-specific Vps33b deficiency induces liver damage, progressive hepatitis, fibrosis, and HCC in male mice, indicating that Vps33b is a crucial contributory factor to hepatocarcinogenesis. Vps33b deficiency-caused liver damage was primarily due to the disorders of structural and functional hepatocyte polarity, which were reflected by the decreased protein levels of E-cadherin because of inaccurate location to lysosomes and polarity defects at both apical and lateral plasma membrane proteins. The results of a mechanism study revealed that Vps33b interacts with VPS33B-interacting protein, which is involved in polarity and apical protein restriction; vesicle-trafficking protein Sec22b; and Flotillin-1 in hepatocytes and is in charge of the normal distribution of polarity-determined proteins. Expression levels of Vps33b negatively correlated with the degree of inflammatory cell infiltration in livers from diethylnitrosamine-induced or transgenic HCC mouse models, and the inflammatory stimuli suppressed the expression of Vps33b in vitro. Conclusion: Down-regulation of Vps33b expression is a critical step for inflammation-driven HCC, and Vps33b serves as an important tumor suppressor in hepatocarcinogenesis.
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Affiliation(s)
- Conghui Wang
- Department of Biochemistry and Molecular Cell Biology, Key Laboratory of Cell Differentiation and Apoptosis of the Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yuqiang Cheng
- Department of Hepatic Surgery VI, Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai, China
| | - Xiuping Zhang
- Department of Hepatic Surgery VI, Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai, China
| | - Nan Li
- Department of Hepatic Surgery VI, Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai, China
| | - Lin Zhang
- Department of Biochemistry and Molecular Cell Biology, Key Laboratory of Cell Differentiation and Apoptosis of the Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Shengdian Wang
- Key Laboratory of Infection and Immunity, Institute of Biophysics, University of Chinese Academy of Sciences, Beijing, China
| | - Xuemei Tong
- Department of Biochemistry and Molecular Cell Biology, Key Laboratory of Cell Differentiation and Apoptosis of the Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Ying Xu
- Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of the Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Guo-Qiang Chen
- Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of the Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Shuqun Cheng
- Department of Hepatic Surgery VI, Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai, China
| | - Xuemei Fan
- Department of Biochemistry and Molecular Cell Biology, Key Laboratory of Cell Differentiation and Apoptosis of the Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Junling Liu
- Department of Biochemistry and Molecular Cell Biology, Key Laboratory of Cell Differentiation and Apoptosis of the Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Collaborative Innovation Center of Hematology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
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9
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Ishida-Yamamoto A, Igawa S, Kishibe M. Molecular basis of the skin barrier structures revealed by electron microscopy. Exp Dermatol 2018; 27:841-846. [PMID: 29704884 DOI: 10.1111/exd.13674] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/16/2018] [Indexed: 02/06/2023]
Abstract
The barrier function of skin is indispensable for terrestrial animals. This function is mainly carried out by the epidermis, more specifically by its granular and cornified layers. The major structural components associated with this function are the intercellular lipid layer, desmosomes, corneodesmosomes, tight junctions, cornified cell envelope and keratin filaments. In this review, we discuss the current knowledge of their ultrastructure, their molecular basis and their relevance to skin disease.
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Affiliation(s)
| | - Satomi Igawa
- Department of Dermatology, Asahikawa Medical University, Asahikawa, Japan
| | - Mari Kishibe
- Department of Dermatology, Asahikawa Medical University, Asahikawa, Japan
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10
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Rogerson C, Gissen P. VPS33B and VIPAR are essential for epidermal lamellar body biogenesis and function. Biochim Biophys Acta Mol Basis Dis 2018; 1864:1609-1621. [PMID: 29409756 PMCID: PMC5906731 DOI: 10.1016/j.bbadis.2018.01.028] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Revised: 01/09/2018] [Accepted: 01/29/2018] [Indexed: 02/06/2023]
Abstract
Mutations in VPS33B and VIPAS39 cause the severe multisystem disorder Arthrogryposis, Renal dysfunction and Cholestasis (ARC) syndrome. Amongst other symptoms, patients with ARC syndrome suffer from severe ichthyosis. Roles for VPS33B and VIPAR have been reported in lysosome-related organelle biogenesis, integrin recycling, collagen homeostasis and maintenance of cell polarity. Mouse knockouts of Vps33b or Vipas39 are good models of ARC syndrome and develop an ichthyotic phenotype. We demonstrate that the skin manifestations in Vps33b and Vipar deficient mice are histologically similar to those of patients with ARC syndrome. Histological, immunofluorescent and electron microscopic analysis of Vps33b and Vipar deficient mouse skin biopsies and isolated primary cells showed that epidermal lamellar bodies, which are essential for skin barrier function, had abnormal morphology and the localisation of lamellar body cargo was disrupted. Stratum corneum formation was affected, with increased corneocyte thickness, decreased thickness of the cornified envelope and reduced deposition of lipids. These defects impact epidermal homeostasis and lead to abnormal barrier formation causing the skin phenotype in Vps33b and Vipar deficient mice and patients with ARC syndrome.
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Affiliation(s)
- Clare Rogerson
- MRC Laboratory for Molecular Cell Biology, University College London, London WC1E 6BT, UK; Institute of Child Health, University College London, London WC1N 1EH, UK.
| | - Paul Gissen
- MRC Laboratory for Molecular Cell Biology, University College London, London WC1E 6BT, UK; Institute of Child Health, University College London, London WC1N 1EH, UK; Inherited Metabolic Diseases Unit, Great Ormond Street Hospital, London WC1N 3JH, UK.
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11
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Cellular interactome analysis of vaccinia virus K7 protein identifies three transport machineries as binding partners for K7. Virus Genes 2017; 53:814-822. [PMID: 28815417 DOI: 10.1007/s11262-017-1504-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Accepted: 08/02/2017] [Indexed: 12/16/2022]
Abstract
Identification of viral-host interacting proteins will contribute to understanding of how poxvirus exploits the host cellular machinery. The vaccinia virus gene K7R encodes a conserved protein K7 in most orthopoxviruses. To gain insight into the biology of K7, we investigated the cellular interactome of K7 by GST pulldown coupled with mass spectrometry. The top categories of identified proteins contained components of trafficking machineries. We selected key components of three transport machineries including coatomer, retromer, and CHEVI to further confirm their binding abilities to K7. Di-lysine motif of K7 is required for its interaction with coatomer, while C terminal leucines in K7 are critical for association of retromer. Our study uncovers the viral-host interactome of vaccinia K7 and reveals three host transport machineries as binding partners of K7, which might have important roles in poxvirus' life cycles.
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