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Mignani L, Facchinello N, Varinelli M, Massardi E, Tiso N, Ravelli C, Mitola S, Schu P, Monti E, Finazzi D, Borsani G, Zizioli D. Deficiency of AP1 Complex Ap1g1 in Zebrafish Model Led to Perturbation of Neurodevelopment, Female and Male Fertility; New Insight to Understand Adaptinopathies. Int J Mol Sci 2023; 24:ijms24087108. [PMID: 37108275 PMCID: PMC10138411 DOI: 10.3390/ijms24087108] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2023] [Revised: 04/03/2023] [Accepted: 04/03/2023] [Indexed: 04/29/2023] Open
Abstract
In vertebrates, two homologous heterotetrameric AP1 complexes regulate the intracellular protein sorting via vesicles. AP-1 complexes are ubiquitously expressed and are composed of four different subunits: γ, β1, μ1 and σ1. Two different complexes are present in eukaryotic cells, AP1G1 (contains γ1 subunit) and AP1G2 (contains γ2 subunit); both are indispensable for development. One additional tissue-specific isoform exists for μ1A, the polarized epithelial cells specific to μ1B; two additional tissue-specific isoforms exist for σ1A: σ1B and σ1C. Both AP1 complexes fulfil specific functions at the trans-Golgi network and endosomes. The use of different animal models demonstrated their crucial role in the development of multicellular organisms and the specification of neuronal and epithelial cells. Ap1g1 (γ1) knockout mice cease development at the blastocyst stage, while Ap1m1 (μ1A) knockouts cease during mid-organogenesis. A growing number of human diseases have been associated with mutations in genes encoding for the subunits of adaptor protein complexes. Recently, a new class of neurocutaneous and neurometabolic disorders affecting intracellular vesicular traffic have been referred to as adaptinopathies. To better understand the functional role of AP1G1 in adaptinopathies, we generated a zebrafish ap1g1 knockout using CRISPR/Cas9 genome editing. Zebrafish ap1g1 knockout embryos cease their development at the blastula stage. Interestingly, heterozygous females and males have reduced fertility and showed morphological alterations in the brain, gonads and intestinal epithelium. An analysis of mRNA profiles of different marker proteins and altered tissue morphologies revealed dysregulated cadherin-mediated cell adhesion. These data demonstrate that the zebrafish model organism enables us to study the molecular details of adaptinopathies and thus also develop treatment strategies.
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Affiliation(s)
- Luca Mignani
- Department of Molecular and Translational Medicine, University of Brescia, Viale Europa, 11, 25123 Brescia, Italy
| | - Nicola Facchinello
- Neuroscience Institute, Italian Research Council (CNR), 35131 Padova, Italy
| | - Marco Varinelli
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, 24126 Bergamo, Italy
| | - Elena Massardi
- Department of Molecular and Translational Medicine, University of Brescia, Viale Europa, 11, 25123 Brescia, Italy
| | - Natascia Tiso
- Department of Biology, University of Padova, Via Ugo Bassi 58/B, 35131 Padova, Italy
| | - Cosetta Ravelli
- Department of Molecular and Translational Medicine, University of Brescia, Viale Europa, 11, 25123 Brescia, Italy
| | - Stefania Mitola
- Department of Molecular and Translational Medicine, University of Brescia, Viale Europa, 11, 25123 Brescia, Italy
- CN3 "Sviluppo di Terapia Genica e Farmaci con Tecnologia ad RNA", 25123 Brescia, Italy
| | - Peter Schu
- Department of Cellular Biochemistry, University Medical Center, Georg-August University, Humboldtallee 23, 37073 Gottingen, Germany
| | - Eugenio Monti
- Department of Molecular and Translational Medicine, University of Brescia, Viale Europa, 11, 25123 Brescia, Italy
| | - Dario Finazzi
- Department of Molecular and Translational Medicine, University of Brescia, Viale Europa, 11, 25123 Brescia, Italy
- Clinical Chemistry Laboratory, ASST Spedali Civili di Brescia, 25123 Brescia, Italy
| | - Giuseppe Borsani
- Department of Molecular and Translational Medicine, University of Brescia, Viale Europa, 11, 25123 Brescia, Italy
| | - Daniela Zizioli
- Department of Molecular and Translational Medicine, University of Brescia, Viale Europa, 11, 25123 Brescia, Italy
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Buser DP, Spang A. Protein sorting from endosomes to the TGN. Front Cell Dev Biol 2023; 11:1140605. [PMID: 36895788 PMCID: PMC9988951 DOI: 10.3389/fcell.2023.1140605] [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: 01/09/2023] [Accepted: 02/09/2023] [Indexed: 02/23/2023] Open
Abstract
Retrograde transport from endosomes to the trans-Golgi network is essential for recycling of protein and lipid cargoes to counterbalance anterograde membrane traffic. Protein cargo subjected to retrograde traffic include lysosomal acid-hydrolase receptors, SNARE proteins, processing enzymes, nutrient transporters, a variety of other transmembrane proteins, and some extracellular non-host proteins such as viral, plant, and bacterial toxins. Efficient delivery of these protein cargo molecules depends on sorting machineries selectively recognizing and concentrating them for their directed retrograde transport from endosomal compartments. In this review, we outline the different retrograde transport pathways governed by various sorting machineries involved in endosome-to-TGN transport. In addition, we discuss how this transport route can be analyzed experimentally.
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Affiliation(s)
| | - Anne Spang
- Biozentrum, University of Basel, Basel, Switzerland
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3
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Shin J, Nile A, Oh JW. Role of adaptin protein complexes in intracellular trafficking and their impact on diseases. Bioengineered 2021; 12:8259-8278. [PMID: 34565296 PMCID: PMC8806629 DOI: 10.1080/21655979.2021.1982846] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2021] [Revised: 09/15/2021] [Accepted: 09/15/2021] [Indexed: 02/07/2023] Open
Abstract
Adaptin proteins (APs) play a crucial role in intracellular cell trafficking. The 'classical' role of APs is carried out by AP1‒3, which bind to clathrin, cargo, and accessory proteins. Accordingly, AP1-3 are crucial for both vesicle formation and sorting. All APs consist of four subunits that are indispensable for their functions. In fact, based on studies using cells, model organism knockdown/knock-out, and human variants, each subunit plays crucial roles and contributes to the specificity of each AP. These studies also revealed that the sorting and intracellular trafficking function of AP can exert varying effects on pathology by controlling features such as cell development, signal transduction related to the apoptosis and proliferation pathways in cancer cells, organelle integrity, receptor presentation, and viral infection. Although the roles and functions of AP1‒3 are relatively well studied, the functions of the less abundant and more recently identified APs, AP4 and AP5, are still to be investigated. Further studies on these APs may enable a better understanding and targeting of specific diseases.APs known or suggested locations and functions.
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Affiliation(s)
- Juhyun Shin
- Department of Stem Cell and Regenerative Biotechnology and Animal Resources Research Center, Konkuk University, Seoul, Republic of Korea
| | - Arti Nile
- Department of Stem Cell and Regenerative Biotechnology and Animal Resources Research Center, Konkuk University, Seoul, Republic of Korea
| | - Jae-Wook Oh
- Department of Stem Cell and Regenerative Biotechnology and Animal Resources Research Center, Konkuk University, Seoul, Republic of Korea
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Schneider K, Adams CE, Elmer KR. Parallel selection on ecologically relevant gene functions in the transcriptomes of highly diversifying salmonids. BMC Genomics 2019; 20:1010. [PMID: 31870285 PMCID: PMC6929470 DOI: 10.1186/s12864-019-6361-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Accepted: 12/01/2019] [Indexed: 12/11/2022] Open
Abstract
Background Salmonid fishes are characterised by a very high level of variation in trophic, ecological, physiological, and life history adaptations. Some salmonid taxa show exceptional potential for fast, within-lake diversification into morphologically and ecologically distinct variants, often in parallel; these are the lake-resident charr and whitefish (several species in the genera Salvelinus and Coregonus). To identify selection on genes and gene categories associated with such predictable diversifications, we analysed 2702 orthogroups (4.82 Mbp total; average 4.77 genes/orthogroup; average 1783 bp/orthogroup). We did so in two charr and two whitefish species and compared to five other salmonid lineages, which do not evolve in such ecologically predictable ways, and one non-salmonid outgroup. Results All selection analyses are based on Coregonus and Salvelinus compared to non-diversifying taxa. We found more orthogroups were affected by relaxed selection than intensified selection. Of those, 122 were under significant relaxed selection, with trends of an overrepresentation of serine family amino acid metabolism and transcriptional regulation, and significant enrichment of behaviour-associated gene functions. Seventy-eight orthogroups were under significant intensified selection and were enriched for signalling process and transcriptional regulation gene ontology terms and actin filament and lipid metabolism gene sets. Ninety-two orthogroups were under diversifying/positive selection. These were enriched for signal transduction, transmembrane transport, and pyruvate metabolism gene ontology terms and often contained genes involved in transcriptional regulation and development. Several orthogroups showed signs of multiple types of selection. For example, orthogroups under relaxed and diversifying selection contained genes such as ap1m2, involved in immunity and development, and slc6a8, playing an important role in muscle and brain creatine uptake. Orthogroups under intensified and diversifying selection were also found, such as genes syn3, with a role in neural processes, and ctsk, involved in bone remodelling. Conclusions Our approach pinpointed relevant genomic targets by distinguishing among different kinds of selection. We found that relaxed, intensified, and diversifying selection affect orthogroups and gene functions of ecological relevance in salmonids. Because they were found consistently and robustly across charr and whitefish and not other salmonid lineages, we propose these genes have a potential role in the replicated ecological diversifications.
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Affiliation(s)
- Kevin Schneider
- Institute of Biodiversity, Animal Health & Comparative Medicine, College of Medical, Veterinary & Life Sciences, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Colin E Adams
- Institute of Biodiversity, Animal Health & Comparative Medicine, College of Medical, Veterinary & Life Sciences, University of Glasgow, Glasgow, G12 8QQ, UK.,Scottish Centre for Ecology and the Natural Environment, University of Glasgow, Rowardennan, G63 0AW, UK
| | - Kathryn R Elmer
- Institute of Biodiversity, Animal Health & Comparative Medicine, College of Medical, Veterinary & Life Sciences, University of Glasgow, Glasgow, G12 8QQ, UK.
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γ2 and γ1AP-1 complexes: Different essential functions and regulatory mechanisms in clathrin-dependent protein sorting. Eur J Cell Biol 2017; 96:356-368. [PMID: 28372831 DOI: 10.1016/j.ejcb.2017.03.008] [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: 02/07/2017] [Revised: 03/24/2017] [Accepted: 03/24/2017] [Indexed: 11/20/2022] Open
Abstract
γ2 adaptin is homologous to γ1, but is only expressed in vertebrates while γ1 is found in all eukaryotes. We know little about γ2 functions and their relation to γ1. γ1 is an adaptin of the heterotetrameric AP-1 complexes, which sort proteins in and do form clathrin-coated transport vesicles and they also regulate maturation of early endosomes. γ1 knockout mice develop only to blastocysts and thus γ2 does not compensate γ1-deficiency in development. γ2 has not been classified as a clathrin-coated vesicle adaptor protein in proteome analyses and functions for monomeric γ2 in endosomal protein sorting have been proposed, but adaptin interaction studies suggested formation of heterotetrameric AP-1/γ2 complexes. We detected γ2 at the trans-Golgi network, on peripheral vesicles and identified γ2 clathrin-coated vesicles in mice. Ubiquitous σ1A and tissue-specific σ1B adaptins bind γ2 and γ1. σ1B knockout in mice does not effect γ1/σ1A AP-1 levels, but γ2/σ1A AP-1 levels are increased in brain and adipocytes. Also γ2 is essential in development. In zebrafish AP-1/γ2 and AP-1/γ1 fulfill different, essential functions in brain and the vascular system.
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Brüser L, Bogdan S. Adherens Junctions on the Move-Membrane Trafficking of E-Cadherin. Cold Spring Harb Perspect Biol 2017; 9:cshperspect.a029140. [PMID: 28096264 DOI: 10.1101/cshperspect.a029140] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Cadherin-based adherens junctions are conserved structures that mediate epithelial cell-cell adhesion in invertebrates and vertebrates. Despite their pivotal function in epithelial integrity, adherens junctions show a remarkable plasticity that is a prerequisite for tissue architecture and morphogenesis. Epithelial cadherin (E-cadherin) is continuously turned over and undergoes cycles of endocytosis, sorting and recycling back to the plasma membrane. Mammalian cell culture and genetically tractable model systems such as Drosophila have revealed conserved, but also distinct, mechanisms in the regulation of E-cadherin membrane trafficking. Here, we discuss our current knowledge about molecules and mechanisms controlling endocytosis, sorting and recycling of E-cadherin during junctional remodeling.
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Affiliation(s)
- Lena Brüser
- Institut für Neurobiologie, Universität Münster, Badestraße 9, 48149 Münster, Germany
| | - Sven Bogdan
- Institut für Neurobiologie, Universität Münster, Badestraße 9, 48149 Münster, Germany.,Institut für Physiologie und Pathophysiologie, Abteilung Molekulare Zellphysiologie, Phillips-Universität Marburg, Emil-Mannkopff-Straße 2, 35037 Marburg, Germany
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7
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Fraher D, Ellis MK, Morrison S, McGee SL, Ward AC, Walder K, Gibert Y. Lipid Abundance in Zebrafish Embryos Is Regulated by Complementary Actions of the Endocannabinoid System and Retinoic Acid Pathway. Endocrinology 2015; 156:3596-609. [PMID: 26181105 DOI: 10.1210/en.2015-1315] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The endocannabinoid system (ECS) and retinoic acid (RA) signaling have been associated with influencing lipid metabolism. We hypothesized that modulation of these pathways could modify lipid abundance in developing vertebrates and that these pathways could have a combinatorial effect on lipid levels. Zebrafish embryos were exposed to chemical treatments altering the activity of the ECS and RA pathway. Embryos were stained with the neutral lipid dye Oil-Red-O (ORO) and underwent whole-mount in situ hybridization (WISH). Mouse 3T3-L1 fibroblasts were differentiated under exposure to RA-modulating chemicals and subsequently stained with ORO and analyzed for gene expression by qRT-PCR. ECS activation and RA exposure increased lipid abundance and the expression of lipoprotein lipase. In addition, RA treatment increased expression of CCAAT/enhancer-binding protein alpha. Both ECS receptors and RA receptor subtypes were separately involved in modulating lipid abundance. Finally, increased ECS or RA activity ameliorated the reduced lipid abundance caused by peroxisome proliferator-activated receptor gamma (PPARγ) inhibition. Therefore, the ECS and RA pathway influence lipid abundance in zebrafish embryos and have an additive effect when treated simultaneously. Furthermore, we demonstrated that these pathways act downstream or independently of PPARγ to influence lipid levels. Our study shows for the first time that the RA and ECS pathways have additive function in lipid abundance during vertebrate development.
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MESH Headings
- 3T3-L1 Cells
- Adipogenesis/drug effects
- Animals
- Azo Compounds/chemistry
- Embryo, Nonmammalian/drug effects
- Embryo, Nonmammalian/embryology
- Embryo, Nonmammalian/metabolism
- Endocannabinoids/metabolism
- Endocannabinoids/pharmacology
- Gene Expression Regulation, Developmental
- In Situ Hybridization
- Lipid Metabolism/genetics
- Lipids/analysis
- Mice
- PPAR gamma/genetics
- PPAR gamma/metabolism
- Receptor, Cannabinoid, CB1/genetics
- Receptor, Cannabinoid, CB1/metabolism
- Receptor, Cannabinoid, CB2/genetics
- Receptor, Cannabinoid, CB2/metabolism
- Receptors, Retinoic Acid/genetics
- Receptors, Retinoic Acid/metabolism
- Retinoic Acid Receptor alpha
- Reverse Transcriptase Polymerase Chain Reaction
- Signal Transduction
- Staining and Labeling/methods
- Tretinoin/metabolism
- Tretinoin/pharmacology
- Zebrafish/embryology
- Zebrafish/genetics
- Zebrafish/metabolism
- Zebrafish Proteins/genetics
- Zebrafish Proteins/metabolism
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Affiliation(s)
- Daniel Fraher
- Metabolic Research Unit, Deakin University School of Medicine, Geelong 3217, Australia
| | - Megan K Ellis
- Metabolic Research Unit, Deakin University School of Medicine, Geelong 3217, Australia
| | - Shona Morrison
- Metabolic Research Unit, Deakin University School of Medicine, Geelong 3217, Australia
| | - Sean L McGee
- Metabolic Research Unit, Deakin University School of Medicine, Geelong 3217, Australia
| | - Alister C Ward
- Metabolic Research Unit, Deakin University School of Medicine, Geelong 3217, Australia
| | - Ken Walder
- Metabolic Research Unit, Deakin University School of Medicine, Geelong 3217, Australia
| | - Yann Gibert
- Metabolic Research Unit, Deakin University School of Medicine, Geelong 3217, Australia
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8
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Fölsch H. Role of the epithelial cell-specific clathrin adaptor complex AP-1B in cell polarity. CELLULAR LOGISTICS 2015; 5:e1074331. [PMID: 27057418 DOI: 10.1080/21592799.2015.1074331] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Revised: 07/07/2015] [Accepted: 07/09/2015] [Indexed: 10/23/2022]
Abstract
Epithelial cells are important for organ development and function. To this end, they polarize their plasma membrane into biochemically and physically distinct membrane domains. The apical membrane faces the luminal site of an organ and the basolateral domain is in contact with the basement membrane and neighboring cells. To establish and maintain this polarity it is important that newly synthesized and endocytic cargos are correctly sorted according to their final destinations at either membrane. Sorting takes place at one of 2 major sorting stations in the cells, the trans-Golgi network (TGN) and recycling endosomes (REs). Polarized sorting may involve epithelial cell-specific sorting adaptors like the AP-1B clathrin adaptor complex. AP-1B facilitates basolateral sorting from REs. This review will discuss various aspects of basolateral sorting in epithelial cells with a special emphasis on AP-1B.
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Affiliation(s)
- Heike Fölsch
- Department of Cell and Molecular Biology; Northwestern University; Feinberg School of Medicine ; Chicago, IL USA
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9
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Nakatsu F, Hase K, Ohno H. The Role of the Clathrin Adaptor AP-1: Polarized Sorting and Beyond. MEMBRANES 2014; 4:747-63. [PMID: 25387275 PMCID: PMC4289864 DOI: 10.3390/membranes4040747] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Revised: 10/27/2014] [Accepted: 10/29/2014] [Indexed: 11/16/2022]
Abstract
The selective transport of proteins or lipids by vesicular transport is a fundamental process supporting cellular physiology. The budding process involves cargo sorting and vesicle formation at the donor membrane and constitutes an important process in vesicular transport. This process is particularly important for the polarized sorting in epithelial cells, in which the cargo molecules need to be selectively sorted and transported to two distinct destinations, the apical or basolateral plasma membrane. Adaptor protein (AP)-1, a member of the AP complex family, which includes the ubiquitously expressed AP-1A and the epithelium-specific AP-1B, regulates polarized sorting at the trans-Golgi network and/or at the recycling endosomes. A growing body of evidence, especially from studies using model organisms and animals, demonstrates that the AP-1-mediated polarized sorting supports the development and physiology of multi-cellular units as functional organs and tissues (e.g., cell fate determination, inflammation and gut immune homeostasis). Furthermore, a possible involvement of AP-1B in the pathogenesis of human diseases, such as Crohn's disease and cancer, is now becoming evident. These data highlight the significant contribution of AP-1 complexes to the physiology of multicellular organisms, as master regulators of polarized sorting in epithelial cells.
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Affiliation(s)
- Fubito Nakatsu
- Department of Cell Biology, Yale University School of Medicine, 295 Congress Avenue, BCMM237, New Haven, CT 06510, USA.
| | - Koji Hase
- Department of Biochemistry, Faculty of Pharmacy, Keio University, Tokyo 105-8512, Japan.
| | - Hiroshi Ohno
- RIKEN Center for Integrative Medical Sciences (IMS), Kanagawa 230-0045, Japan.
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10
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Affiliation(s)
- Yusong Guo
- Department of Molecular and Cell Biology, Howard Hughes Medical Institute, University of California, Berkeley, California 94720-3200;
| | - Daniel W. Sirkis
- Department of Molecular and Cell Biology, Howard Hughes Medical Institute, University of California, Berkeley, California 94720-3200;
| | - Randy Schekman
- Department of Molecular and Cell Biology, Howard Hughes Medical Institute, University of California, Berkeley, California 94720-3200;
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11
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Baltes J, Larsen JV, Radhakrishnan K, Geumann C, Kratzke M, Petersen CM, Schu P. σ1B adaptin regulates adipogenesis by mediating the sorting of sortilin in adipose tissue. J Cell Sci 2014; 127:3477-87. [PMID: 24928897 DOI: 10.1242/jcs.146886] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Here, we describe altered sorting of sortilin in adipocytes deficient for the σ1B-containing AP-1 complex, leading to the inhibition of adipogenesis. The AP-1 complex mediates protein sorting between the trans-Golgi network and endosomes. Vertebrates express three AP1 σ1 subunit isoforms - σ1A, σ1B and σ1C (also known as AP1S1, AP1S2 and AP1S3, respectively). σ1B-deficient mice display impaired recycling of synaptic vesicles and lipodystrophy. Here, we show that sortilin is overexpressed in adipose tissue from σ1B(-/-) mice, and that its overexpression in wild-type cells is sufficient to suppress adipogenesis. σ1B-specific binding of sortilin requires the sortilin DxxD-x12-DSxxxL motif. σ1B deficiency does not lead to a block of sortilin transport out of a specific organelle, but the fraction that reaches lysosomes is reduced. Sortilin binds to the receptor DLK1, an inhibitor of adipocyte differentiation, and the overexpression of sortilin prevents DLK1 downregulation, leading to enhanced inhibition of adipogenesis. DLK1 and sortilin expression are not increased in the brain tissue of σ1B(-/-) mice, although this is the tissue with the highest expression of σ1B and sortilin. Thus, adipose-tissue-specific and σ1B-dependent routes for the transport of sortilin exist and are involved in the regulation of adipogenesis and adipose-tissue mass.
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Affiliation(s)
- Jennifer Baltes
- Georg-August University Göttingen, Department for Cellular Biochemistry, Humboldtallee 23, D-37073 Göttingen, Germany
| | - Jakob Vejby Larsen
- MIND Center Department of Biomedicine, Ole Worms Allé 3, Aarhus University, 8000 Aarhus, Denmark
| | - Karthikeyan Radhakrishnan
- Georg-August University Göttingen, Department for Cellular Biochemistry, Humboldtallee 23, D-37073 Göttingen, Germany
| | - Constanze Geumann
- Georg-August University Göttingen, Department for Cellular Biochemistry, Humboldtallee 23, D-37073 Göttingen, Germany
| | - Manuel Kratzke
- Georg-August University Göttingen, Department for Cellular Biochemistry, Humboldtallee 23, D-37073 Göttingen, Germany
| | - Claus Munck Petersen
- MIND Center Department of Biomedicine, Ole Worms Allé 3, Aarhus University, 8000 Aarhus, Denmark
| | - Peter Schu
- Georg-August University Göttingen, Department for Cellular Biochemistry, Humboldtallee 23, D-37073 Göttingen, Germany
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12
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Kocmarek AL, Ferguson MM, Danzmann RG. Differential gene expression in small and large rainbow trout derived from two seasonal spawning groups. BMC Genomics 2014; 15:57. [PMID: 24450799 PMCID: PMC3931318 DOI: 10.1186/1471-2164-15-57] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Accepted: 01/17/2014] [Indexed: 12/24/2022] Open
Abstract
Background Growth in fishes is regulated via many environmental and physiological factors and is shaped by the genetic background of each individual. Previous microarray studies of salmonid growth have examined fish experiencing either muscle wastage or accelerated growth patterns following refeeding, or the influence of growth hormone and transgenesis. This study determines the gene expression profiles of genetically unmanipulated large and small fish from a domesticated salmonid strain reared on a typical feeding regime. Gene expression profiles of white muscle and liver from rainbow trout (Oncorhynchus mykiss) from two seasonal spawning groups (September and December lots) within a single strain were examined when the fish were 15 months of age to assess the influence of season (late fall vs. onset of spring) and body size (large vs. small). Results Although IGFBP1 gene expression was up-regulated in the livers of small fish in both seasonal lots, few expression differences were detected in the liver overall. Faster growing Dec. fish showed a greater number of differences in white muscle expression compared to Sept. fish. Significant differences in the GO Generic Level 3 categories ‘response to external stimulus’, ‘establishment of localization’, and ‘response to stress’ were detected in white muscle tissue between large and small fish. Larger fish showed up-regulation of cytoskeletal component genes while many genes related to myofibril components of muscle tissue were up-regulated in small fish. Most of the genes up-regulated in large fish within the ‘response to stress’ category are involved in immunity while in small fish most of these gene functions are related to apoptosis. Conclusions A higher proportion of genes in white muscle compared to liver showed similar patterns of up- or down-regulation within the same size class across seasons supporting their utility as biomarkers for growth in rainbow trout. Differences between large and small Sept. fish in the ‘response to stress’ and ‘response to external stimulus’ categories for white muscle tissue, suggests that smaller fish have a greater inability to handle stress compared to the large fish. Sampling season had a significant impact on the expression of genes related to the growth process in rainbow trout.
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Affiliation(s)
- Andrea L Kocmarek
- Department of Integrative Biology, University of Guelph, 50 Stone Rd, East, Guelph, Ontario N1G 2W1, Canada.
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13
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Gariano G, Guarienti M, Bresciani R, Borsani G, Carola G, Monti E, Giuliani R, Rezzani R, Bonomini F, Preti A, Schu P, Zizioli D. Analysis of three μ1-AP1 subunits during zebrafish development. Dev Dyn 2013; 243:299-314. [PMID: 24123392 DOI: 10.1002/dvdy.24071] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2013] [Revised: 09/25/2013] [Accepted: 09/27/2013] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND The family of AP-1 complexes mediates protein sorting in the late secretory pathway and it is essential for the development of mammals. The ubiquitously expressed AP-1A complex consists of four adaptins γ1, β1, μ1A, and σ1A. AP-1A mediates protein transport between the trans-Golgi network and early endosomes. The polarized epithelia AP-1B complex contains the μ1B-adaptin. AP-1B mediates specific transport of proteins from basolateral recycling endosomes to the basolateral plasma membrane of polarized epithelial cells. RESULTS Analysis of the zebrafish genome revealed the existence of three μ1-adaptin genes, encoding μ1A, μ1B, and the novel isoform μ1C, which is not found in mammals. μ1C shows 80% sequence identity with μ1A and μ1B. The μ1C expression pattern largely overlaps with that of μ1A, while μ1B is expressed in epithelial cells. By knocking-down the synthesis of μ1A, μ1B and μ1C with antisense morpholino techniques we demonstrate that each of these μ1 adaptins is essential for zebrafish development, with μ1A and μ1C being involved in central nervous system development and μ1B in kidney, gut and liver formation. CONCLUSIONS Zebrafish is unique in expressing three AP-1 complexes: AP-1A, AP-1B, and AP-1C. Our results demonstrate that they are not redundant and that each of them has specific functions, which cannot be fulfilled by one of the other isoforms. Each of the μ1 adaptins appears to mediate specific molecular mechanisms essential for early developmental processes, which depends on specific intracellular vesicular protein sorting pathways.
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Affiliation(s)
- Giuseppina Gariano
- Unit of Experimental Oncology and Immunology, Department of Molecular and Translational Medicine University of Brescia, Italy
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Mutations in ap1b1 cause mistargeting of the Na(+)/K(+)-ATPase pump in sensory hair cells. PLoS One 2013; 8:e60866. [PMID: 23593334 PMCID: PMC3625210 DOI: 10.1371/journal.pone.0060866] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2013] [Accepted: 03/04/2013] [Indexed: 11/19/2022] Open
Abstract
The hair cells of the inner ear are polarized epithelial cells with a specialized structure at the apical surface, the mechanosensitive hair bundle. Mechanotransduction occurs within the hair bundle, whereas synaptic transmission takes place at the basolateral membrane. The molecular basis of the development and maintenance of the apical and basal compartments in sensory hair cells is poorly understood. Here we describe auditory/vestibular mutants isolated from forward genetic screens in zebrafish with lesions in the adaptor protein 1 beta subunit 1 (ap1b1) gene. Ap1b1 is a subunit of the adaptor complex AP-1, which has been implicated in the targeting of basolateral membrane proteins. In ap1b1 mutants we observed that although the overall development of the inner ear and lateral-line organ appeared normal, the sensory epithelium showed progressive signs of degeneration. Mechanically-evoked calcium transients were reduced in mutant hair cells, indicating that mechanotransduction was also compromised. To gain insight into the cellular and molecular defects in ap1b1 mutants, we examined the localization of basolateral membrane proteins in hair cells. We observed that the Na(+)/K(+)-ATPase pump (NKA) was less abundant in the basolateral membrane and was mislocalized to apical bundles in ap1b1 mutant hair cells. Accordingly, intracellular Na(+) levels were increased in ap1b1 mutant hair cells. Our results suggest that Ap1b1 is essential for maintaining integrity and ion homeostasis in hair cells.
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15
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Poirier S, Mayer G, Murphy SR, Garver WS, Chang TY, Schu P, Seidah NG. The cytosolic adaptor AP-1A is essential for the trafficking and function of Niemann-Pick type C proteins. Traffic 2013; 14:458-69. [PMID: 23350547 DOI: 10.1111/tra.12046] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2012] [Revised: 01/16/2013] [Accepted: 01/25/2013] [Indexed: 01/09/2023]
Abstract
Niemann-Pick type C (NPC) disease is a fatal neurodegenerative disorder characterized by over-accumulation of low-density lipoprotein-derived cholesterol and glycosphingolipids in late endosomes/lysosomes (LE/L) throughout the body. Human mutations in either NPC1 or NPC2 genes have been directly associated with impaired cholesterol efflux from LE/L. Independent from its role in cholesterol homeostasis and its NPC2 partner, NPC1 was unexpectedly identified as a critical player controlling intracellular entry of filoviruses such as Ebola. In this study, a yeast three-hybrid system revealed that the NPC1 cytoplasmic tail directly interacts with the clathrin adaptor protein AP-1 via its acidic/di-leucine motif. Consequently, a nonfunctional AP-1A cytosolic complex resulted in a typical NPC-like phenotype mainly due to a direct impairment of NPC1 trafficking to LE/L and a partial secretion of NPC2. Furthermore, the mislocalization of NPC1 was not due to cholesterol accumulation in LE/L, as it was not rescued upon treatment with Mβ-cyclodextrin, which almost completely eliminated intracellular free cholesterol. Our cumulative data demonstrate that the cytosolic clathrin adaptor AP-1A is essential for the lysosomal targeting and function of NPC1 and NPC2.
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Affiliation(s)
- Steve Poirier
- Laboratory of Biochemical Neuroendocrinology, Clinical Research Institute of Montreal, Montréal, QC, Canada
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16
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Kametaka S, Kametaka A, Yonekura S, Haruta M, Takenoshita S, Goto S, Waguri S. AP-1 clathrin adaptor and CG8538/Aftiphilin are involved in Notch signaling during eye development in Drosophila melanogaster. J Cell Sci 2012; 125:634-48. [PMID: 22389401 DOI: 10.1242/jcs.090167] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Clathrin adaptor protein complex-1 (AP-1) and its accessory proteins play a role in the sorting of integral membrane proteins at the trans-Golgi network and endosomes. Their physiological functions in complex organisms, however, are not fully understood. In this study, we found that CG8538p, an uncharacterized Drosophila protein, shares significant structural and functional characteristics with Aftiphilin, a mammalian AP-1 accessory protein. The Drosophila Aftiphilin was shown to interact directly with the ear domain of γ-adaptin of Drosophila AP-1, but not with the GAE domain of Drosophila GGA. In S2 cells, Drosophila Aftiphilin and AP-1 formed a complex and colocalized at the Golgi compartment. Moreover, tissue-specific depletion of AP-1 or Aftiphilin in the developing eyes resulted in a disordered alignment of photoreceptor neurons in larval stage and roughened eyes with aberrant ommatidia in adult flies. Furthermore, AP-1-depleted photoreceptor neurons showed an intracellular accumulation of a Notch regulator, Scabrous, and downregulation of Notch by promoting its degradation in the lysosomes. These results suggest that AP-1 and Aftiphilin are cooperatively involved in the intracellular trafficking of Notch during eye development in Drosophila.
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Affiliation(s)
- Satoshi Kametaka
- Department of Anatomy and Histology, Fukushima Medical University, 1 Hikarigaoka, Fukushima, Fukushima 960-1295, Japan.
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17
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Farías GG, Cuitino L, Guo X, Ren X, Jarnik M, Mattera R, Bonifacino JS. Signal-mediated, AP-1/clathrin-dependent sorting of transmembrane receptors to the somatodendritic domain of hippocampal neurons. Neuron 2012; 75:810-23. [PMID: 22958822 PMCID: PMC3439821 DOI: 10.1016/j.neuron.2012.07.007] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/03/2012] [Indexed: 11/22/2022]
Abstract
Plasma membranes of the somatodendritic and axonal domains of neurons are known to have different protein compositions, but the molecular mechanisms that determine this polarized protein distribution remain poorly understood. Herein we show that somatodendritic sorting of various transmembrane receptors in rat hippocampal neurons is mediated by recognition of signals within the cytosolic domains of the proteins by the μ1A subunit of the adaptor protein-1 (AP-1) complex. This complex, in conjunction with clathrin, functions in the neuronal soma to exclude somatodendritic proteins from axonal transport carriers. Perturbation of this process affects dendritic spine morphology and decreases the number of synapses. These findings highlight the primary recognition event that underlies somatodendritic sorting and contribute to the evolving view of AP-1 as a global regulator of cell polarity.
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Affiliation(s)
- Ginny G. Farías
- Cell Biology and Metabolism Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development National Institutes of Health, Bethesda, MD 20892, USA
| | - Loreto Cuitino
- Cell Biology and Metabolism Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development National Institutes of Health, Bethesda, MD 20892, USA
| | - Xiaoli Guo
- Cell Biology and Metabolism Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development National Institutes of Health, Bethesda, MD 20892, USA
| | - Xuefeng Ren
- Cell Biology and Metabolism Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development National Institutes of Health, Bethesda, MD 20892, USA
| | - Michal Jarnik
- Cell Biology and Metabolism Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development National Institutes of Health, Bethesda, MD 20892, USA
| | - Rafael Mattera
- Cell Biology and Metabolism Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development National Institutes of Health, Bethesda, MD 20892, USA
| | - Juan S. Bonifacino
- Cell Biology and Metabolism Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development National Institutes of Health, Bethesda, MD 20892, USA
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18
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Benhra N, Lallet S, Cotton M, Le Bras S, Dussert A, Le Borgne R. AP-1 controls the trafficking of Notch and Sanpodo toward E-cadherin junctions in sensory organ precursors. Curr Biol 2010; 21:87-95. [PMID: 21194948 DOI: 10.1016/j.cub.2010.12.010] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2010] [Revised: 11/11/2010] [Accepted: 12/06/2010] [Indexed: 02/01/2023]
Abstract
In Drosophila melanogaster, external sensory organs develop from a single sensory organ precursor (SOP). The SOP divides asymmetrically to generate daughter cells, whose fates are governed by differential Notch activation. Here we show that the clathrin adaptor AP-1 complex, localized at the trans Golgi network and in recycling endosomes, acts as a negative regulator of Notch signaling. Inactivation of AP-1 causes ligand-dependent activation of Notch, leading to a fate transformation within sensory organs. Loss of AP-1 affects neither cell polarity nor the unequal segregation of the cell fate determinants Numb and Neuralized. Instead, it causes apical accumulation of the Notch activator Sanpodo and stabilization of both Sanpodo and Notch at the interface between SOP daughter cells, where DE-cadherin is localized. Endocytosis-recycling assays reveal that AP-1 acts in recycling endosomes to prevent internalized Spdo from recycling toward adherens junctions. Because AP-1 does not prevent endocytosis and recycling of the Notch ligand Delta, our data indicate that the DE-cadherin junctional domain may act as a launching pad through which endocytosed Notch ligand is trafficked for signaling.
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Affiliation(s)
- Najate Benhra
- CNRS UMR 6061-Institut de Génétique et Développement de Rennes, Université de Rennes 1, 2 avenue du Professeur Bernard, 35000 Rennes, France
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