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Pemberton JG, Tenkova T, Felgner P, Zimmerberg J, Balla T, Heuser J. Defining the EM-signature of successful cell-transfection. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.07.583927. [PMID: 38496608 PMCID: PMC10942431 DOI: 10.1101/2024.03.07.583927] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/19/2024]
Abstract
In this report, we describe the architecture of Lipofectamine 2000 and 3000 transfection- reagents, as they appear inside of transfected cells, using classical transmission electron microscopy (EM). We also demonstrate that they provoke consistent structural changes after they have entered cells, changes that not only provide new insights into the mechanism of action of these particular transfection-reagents, but also provide a convenient and robust method for identifying by EM which cells in any culture have been successfully transfected. This also provides clues to the mechanism(s) of their toxic effects, when they are applied in excess. We demonstrate that after being bulk-endocytosed by cells, the cationic spheroids of Lipofectamine remain intact throughout the entire time of culturing, but escape from their endosomes and penetrate directly into the cytoplasm of the cell. In so doing, they provoke a stereotypical recruitment and rearrangement of endoplasmic reticulum (ER), and they ultimately end up escaping into the cytoplasm and forming unique 'inclusion-bodies.' Once free in the cytoplasm, they also invariably develop dense and uniform coatings of cytoplasmic ribosomes on their surfaces, and finally, they become surrounded by 'annulate' lamellae' of the ER. In the end, these annulate-lamellar enclosures become the ultrastructural 'signatures' of these inclusion-bodies, and serve to positively and definitively identify all cells that have been effectively transfected. Importantly, these new EM-observations define several new and unique properties of these classical Lipofectamines, and allow them to be discriminated from other lipoidal or particulate transfection-reagents, which we find do not physically break out of endosomes or end up in inclusion bodies, and in fact, provoke absolutely none of these 'signature' cytoplasmic reactions.
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2
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Kersten N, Farías GG. A voyage from the ER: spatiotemporal insights into polarized protein secretion in neurons. Front Cell Dev Biol 2023; 11:1333738. [PMID: 38188013 PMCID: PMC10766823 DOI: 10.3389/fcell.2023.1333738] [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: 11/05/2023] [Accepted: 12/04/2023] [Indexed: 01/09/2024] Open
Abstract
To function properly, neurons must maintain a proteome that differs in their somatodendritic and axonal domain. This requires the polarized sorting of newly synthesized secretory and transmembrane proteins into different vesicle populations as they traverse the secretory pathway. Although the trans-Golgi-network is generally considered to be the main sorting hub, this sorting process may already begin at the ER and continue through the Golgi cisternae. At each step in the sorting process, specificity is conferred by adaptors, GTPases, tethers, and SNAREs. Besides this, local synthesis and unconventional protein secretion may contribute to the polarized proteome to enable rapid responses to stimuli. For some transmembrane proteins, some of the steps in the sorting process are well-studied. These will be highlighted here. The universal rules that govern polarized protein sorting remain unresolved, therefore we emphasize the need to approach this problem in an unbiased, top-down manner. Unraveling these rules will contribute to our understanding of neuronal development and function in health and disease.
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Affiliation(s)
- Noortje Kersten
- Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, Utrecht, Netherlands
| | - Ginny G Farías
- Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, Utrecht, Netherlands
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3
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Cheng CY, Hernández J, Turkewitz AP. VPS8D, a CORVET subunit, is required to maintain the contractile vacuole complex in Tetrahymena thermophila. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.07.566071. [PMID: 37986963 PMCID: PMC10659352 DOI: 10.1101/2023.11.07.566071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2023]
Abstract
Contractile vacuole complexes (CVCs) are complex osmoregulatory organelles, with vesicular (bladder) and tubular (spongiome) subcompartments. The mechanisms that underlie their formation and maintenance within the eukaryotic endomembrane network are poorly understood. In the Ciliate Tetrahymena thermophila, six differentiated CORVETs (class C core vacuole/endosome tethering complexes), with Vps8 subunits designated A-F, are likely to direct endosomal trafficking. Vps8Dp localizes to both bladder and spongiome. We show by inducible knockdown that VPS8D is essential to CVC organization and function. VPS8D knockdown increased susceptibility to osmotic shock, tolerated in the wildtype but triggering irreversible lethal swelling in the mutant. The knockdown rapidly triggered contraction of the spongiome and lengthened the period of the bladder contractile cycle. More prolonged knockdown resulted in disassembly of both the spongiome and bladder, and dispersal of proteins associated with those compartments. In stressed cells where the normally singular bladder is replaced by numerous vesicles bearing bladder markers, Vps8Dp concentrated conspicuously at long-lived inter-vesicle contact sites, consistent with tethering activity. Similarly, Vps8Dp in cell-free preparations accumulated at junctions formed after vacuoles came into close contact. Also consistent with roles for Vps8Dp in tethering and/or fusion were the emergence in knockdown cells of multiple vacuole-related structures, replacing the single bladder.
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Affiliation(s)
- Chao-Yin Cheng
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL, USA
| | - Josefina Hernández
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL, USA
| | - Aaron P. Turkewitz
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL, USA
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4
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Terawaki S, Vasilev F, Moriwaki T, Otomo T. HOPS, CORVET and newly-identified Hybrid tethering complexes contribute differentially towards multiple modes of endocytosis. Sci Rep 2023; 13:18734. [PMID: 37907479 PMCID: PMC10618185 DOI: 10.1038/s41598-023-45418-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Accepted: 10/19/2023] [Indexed: 11/02/2023] Open
Abstract
Vesicular transport driven by membrane trafficking systems conserved in eukaryotes is critical to cellular functionality and homeostasis. It is known that homotypic fusion and vacuole protein sorting (HOPS) and class C core endosomal vacuole tethering (CORVET) interact with Rab-GTPases and SNARE proteins to regulate vesicle transport, fusion, and maturation in autophagy and endocytosis pathways. In this study, we identified two novel "Hybrid" tethering complexes in mammalian cells in which one of the subunits of HOPS or CORVET is replaced with the subunit from the other. Substrates taken up by receptor-mediated endocytosis or pinocytosis were transported by distinctive pathways, and the newly identified hybrid complexes contributed to pinocytosis in the presence of HOPS, whereas receptor-mediated endocytosis was exclusively dependent on HOPS. Our study provides new insights into the molecular mechanisms of the endocytic pathway and the function of the vacuolar protein sorting-associated (VPS) protein family.
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Affiliation(s)
- Seigo Terawaki
- Department of Molecular and Genetic Medicine, Kawasaki Medical School, 577 Matsushima, Kurashiki, Okayama, 701-0192, Japan
| | - Filipp Vasilev
- Department of Molecular and Genetic Medicine, Kawasaki Medical School, 577 Matsushima, Kurashiki, Okayama, 701-0192, Japan
| | - Takahito Moriwaki
- Department of Molecular and Genetic Medicine, Kawasaki Medical School, 577 Matsushima, Kurashiki, Okayama, 701-0192, Japan
| | - Takanobu Otomo
- Department of Molecular and Genetic Medicine, Kawasaki Medical School, 577 Matsushima, Kurashiki, Okayama, 701-0192, Japan.
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5
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Jain S, Yee AG, Maas J, Gierok S, Xu H, Stansil J, Eriksen J, Nelson AB, Silm K, Ford CP, Edwards RH. Adaptor protein-3 produces synaptic vesicles that release phasic dopamine. Proc Natl Acad Sci U S A 2023; 120:e2309843120. [PMID: 37812725 PMCID: PMC10589613 DOI: 10.1073/pnas.2309843120] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Accepted: 09/06/2023] [Indexed: 10/11/2023] Open
Abstract
The burst firing of midbrain dopamine neurons releases a phasic dopamine signal that mediates reinforcement learning. At many synapses, however, high firing rates deplete synaptic vesicles (SVs), resulting in synaptic depression that limits release. What accounts for the increased release of dopamine by stimulation at high frequency? We find that adaptor protein-3 (AP-3) and its coat protein VPS41 promote axonal dopamine release by targeting vesicular monoamine transporter VMAT2 to the axon rather than dendrites. AP-3 and VPS41 also produce SVs that respond preferentially to high-frequency stimulation, independent of their role in axonal polarity. In addition, conditional inactivation of VPS41 in dopamine neurons impairs reinforcement learning, and this involves a defect in the frequency dependence of release rather than the amount of dopamine released. Thus, AP-3 and VPS41 promote the axonal polarity of dopamine release but enable learning by producing a distinct population of SVs tuned specifically to high firing frequency that confers the phasic release of dopamine.
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Affiliation(s)
- Shweta Jain
- Department of Physiology, University of California School of Medicine, San Francisco, CA94143
- Department of Neurology, University of California School of Medicine, San Francisco, CA94143
| | - Andrew G. Yee
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO80045
| | - James Maas
- Department of Physiology, University of California School of Medicine, San Francisco, CA94143
- Department of Neurology, University of California School of Medicine, San Francisco, CA94143
| | - Sarah Gierok
- Department of Physiology, University of California School of Medicine, San Francisco, CA94143
- Department of Neurology, University of California School of Medicine, San Francisco, CA94143
| | - Hongfei Xu
- Department of Physiology, University of California School of Medicine, San Francisco, CA94143
- Department of Neurology, University of California School of Medicine, San Francisco, CA94143
| | - Jasmine Stansil
- Department of Neurology, University of California School of Medicine, San Francisco, CA94143
| | - Jacob Eriksen
- Department of Physiology, University of California School of Medicine, San Francisco, CA94143
- Department of Neurology, University of California School of Medicine, San Francisco, CA94143
| | - Alexandra B. Nelson
- Department of Neurology, University of California School of Medicine, San Francisco, CA94143
- Aligning Science Across Parkinson’s Collaborative Research Network, Chevy Chase, MD20815
| | - Katlin Silm
- Department of Physiology, University of California School of Medicine, San Francisco, CA94143
- Department of Neurology, University of California School of Medicine, San Francisco, CA94143
| | - Christopher P. Ford
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO80045
- Aligning Science Across Parkinson’s Collaborative Research Network, Chevy Chase, MD20815
| | - Robert H. Edwards
- Department of Physiology, University of California School of Medicine, San Francisco, CA94143
- Department of Neurology, University of California School of Medicine, San Francisco, CA94143
- Aligning Science Across Parkinson’s Collaborative Research Network, Chevy Chase, MD20815
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6
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Hummer BH, Carter T, Sellers BL, Triplett JD, Asensio CS. Identification of the functional domain of the dense core vesicle biogenesis factor HID-1. PLoS One 2023; 18:e0291977. [PMID: 37751424 PMCID: PMC10522040 DOI: 10.1371/journal.pone.0291977] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Accepted: 09/08/2023] [Indexed: 09/28/2023] Open
Abstract
Large dense core vesicles (LDCVs) mediate the regulated release of neuropeptides and peptide hormones. HID-1 is a trans-Golgi network (TGN) localized peripheral membrane protein contributing to LDCV formation. There is no information about HID-1 structure or domain architecture, and thus it remains unknown how HID-1 binds to the TGN and performs its function. We report that the N-terminus of HID-1 mediates membrane binding through a myristoyl group with a polybasic amino acid patch but lacks specificity for the TGN. In addition, we show that the C-terminus serves as the functional domain. Indeed, this isolated domain, when tethered to the TGN, can rescue the neuroendocrine secretion and sorting defects observed in HID-1 KO cells. Finally, we report that a point mutation within that domain, identified in patients with endocrine and neurological deficits, leads to loss of function.
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Affiliation(s)
- Blake H. Hummer
- Department of Biological Sciences, University of Denver, Denver, CO, United States of America
| | - Theodore Carter
- Department of Biological Sciences, University of Denver, Denver, CO, United States of America
| | - Breanna L. Sellers
- Department of Biological Sciences, University of Denver, Denver, CO, United States of America
| | - Jenna D. Triplett
- Department of Biological Sciences, University of Denver, Denver, CO, United States of America
| | - Cedric S. Asensio
- Department of Biological Sciences, University of Denver, Denver, CO, United States of America
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7
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Jain S, Yee AG, Maas J, Gierok S, Xu H, Stansil J, Eriksen J, Nelson A, Silm K, Ford CP, Edwards RH. Adaptor Protein-3 Produces Synaptic Vesicles that Release Phasic Dopamine. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.07.552338. [PMID: 37609166 PMCID: PMC10441354 DOI: 10.1101/2023.08.07.552338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/24/2023]
Abstract
The burst firing of midbrain dopamine neurons releases a phasic dopamine signal that mediates reinforcement learning. At many synapses, however, high firing rates deplete synaptic vesicles (SVs), resulting in synaptic depression that limits release. What accounts for the increased release of dopamine by stimulation at high frequency? We find that adaptor protein-3 (AP-3) and its coat protein VPS41 promote axonal dopamine release by targeting vesicular monoamine transporter VMAT2 to the axon rather than dendrites. AP-3 and VPS41 also produce SVs that respond preferentially to high frequency stimulation, independent of their role in axonal polarity. In addition, conditional inactivation of VPS41 in dopamine neurons impairs reinforcement learning, and this involves a defect in the frequency dependence of release rather than the amount of dopamine released. Thus, AP-3 and VPS41 promote the axonal polarity of dopamine release but enable learning by producing a novel population of SVs tuned specifically to high firing frequency that confers the phasic release of dopamine.
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Affiliation(s)
- Shweta Jain
- Department of Physiology, UCSF School of Medicine, San Francisco USA
- Department of Neurology, UCSF School of Medicine, San Francisco USA
| | - Andrew G. Yee
- Department of Pharmacology, University of Colorado School of Medicine, Aurora USA
| | - James Maas
- Department of Physiology, UCSF School of Medicine, San Francisco USA
- Department of Neurology, UCSF School of Medicine, San Francisco USA
| | - Sarah Gierok
- Department of Physiology, UCSF School of Medicine, San Francisco USA
- Department of Neurology, UCSF School of Medicine, San Francisco USA
| | - Hongfei Xu
- Department of Physiology, UCSF School of Medicine, San Francisco USA
- Department of Neurology, UCSF School of Medicine, San Francisco USA
| | - Jasmine Stansil
- Department of Neurology, UCSF School of Medicine, San Francisco USA
| | - Jacob Eriksen
- Department of Physiology, UCSF School of Medicine, San Francisco USA
- Department of Neurology, UCSF School of Medicine, San Francisco USA
| | - Alexandra Nelson
- Department of Neurology, UCSF School of Medicine, San Francisco USA
| | - Katlin Silm
- Department of Physiology, UCSF School of Medicine, San Francisco USA
- Department of Neurology, UCSF School of Medicine, San Francisco USA
| | - Christopher P. Ford
- Department of Pharmacology, University of Colorado School of Medicine, Aurora USA
| | - Robert H. Edwards
- Department of Physiology, UCSF School of Medicine, San Francisco USA
- Department of Neurology, UCSF School of Medicine, San Francisco USA
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8
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Real N, Villar I, Serrano I, Guiu-Aragonés C, Martín-Hernández AM. Mutations in CmVPS41 controlling resistance to cucumber mosaic virus display specific subcellular localization. PLANT PHYSIOLOGY 2023; 191:1596-1611. [PMID: 36527697 PMCID: PMC10022621 DOI: 10.1093/plphys/kiac583] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Accepted: 11/29/2022] [Indexed: 06/17/2023]
Abstract
Resistance to cucumber mosaic virus (CMV) in melon (Cucumis melo L.) has been described in several exotic accessions and is controlled by a recessive resistance gene, cmv1, that encodes a vacuolar protein sorting 41 (CmVPS41). cmv1 prevents systemic infection by restricting the virus to the bundle sheath cells, preventing viral phloem entry. CmVPS41 from different resistant accessions carries two causal mutations, either a G85E change, found in Pat-81 and Freeman's cucumber, or L348R, found in PI161375, cultivar Songwhan Charmi (SC). Here, we analyzed the subcellular localization of CmVPS41 in Nicotiana benthamiana and found differential structures in resistant and susceptible accessions. Susceptible accessions showed nuclear and membrane spots and many transvacuolar strands, whereas the resistant accessions showed many intravacuolar invaginations. These specific structures colocalized with late endosomes. Artificial CmVPS41 carrying individual mutations causing resistance in the genetic background of CmVPS41 from the susceptible variety Piel de Sapo (PS) revealed that the structure most correlated with resistance was the absence of transvacuolar strands. Coexpression of CmVPS41 with viral movement proteins, the determinant of virulence, did not change these localizations; however, infiltration of CmVPS41 from either SC or PS accessions in CMV-infected N. benthamiana leaves showed a localization pattern closer to each other, with up to 30% cells showing some membrane spots in the CmVPS41SC and fewer transvacuolar strands (reduced from a mean of 4 to 1-2) with CmVPS41PS. Our results suggest that the distribution of CmVPS41PS in late endosomes includes transvacuolar strands that facilitate CMV infection and that CmVPS41 re-localizes during viral infection.
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Affiliation(s)
- Núria Real
- Centre for Research in Agricultural Genomics (CRAG) CSIC-IRTA-UAB-UB, C/Vall Moronta, Edifici CRAG, Bellaterra (Cerdanyola del Vallés), 08193 Barcelona, Spain
| | - Irene Villar
- Centre for Research in Agricultural Genomics (CRAG) CSIC-IRTA-UAB-UB, C/Vall Moronta, Edifici CRAG, Bellaterra (Cerdanyola del Vallés), 08193 Barcelona, Spain
- Universidad de Zaragoza, Calle Pedro Cerbuna, 12, 50009 Zaragoza, Spain
| | - Irene Serrano
- Laboratoire des Interactions des Plantes et Microorganismes, CNRS, 31326 Toulouse, France
| | - Cèlia Guiu-Aragonés
- Centre for Research in Agricultural Genomics (CRAG) CSIC-IRTA-UAB-UB, C/Vall Moronta, Edifici CRAG, Bellaterra (Cerdanyola del Vallés), 08193 Barcelona, Spain
| | - Ana Montserrat Martín-Hernández
- Centre for Research in Agricultural Genomics (CRAG) CSIC-IRTA-UAB-UB, C/Vall Moronta, Edifici CRAG, Bellaterra (Cerdanyola del Vallés), 08193 Barcelona, Spain
- Institut de Recerca i Tecnologia Agroalimentàries (IRTA), Edifici CRAG, C/ Vall Moronta, Bellaterra (Cerdanyola del Vallés), 08193 Barcelona, Spain
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9
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Kümmel D, Herrmann E, Langemeyer L, Ungermann C. Molecular insights into endolysosomal microcompartment formation and maintenance. Biol Chem 2022; 404:441-454. [PMID: 36503831 DOI: 10.1515/hsz-2022-0294] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Accepted: 11/22/2022] [Indexed: 12/14/2022]
Abstract
Abstract
The endolysosomal system of eukaryotic cells has a key role in the homeostasis of the plasma membrane, in signaling and nutrient uptake, and is abused by viruses and pathogens for entry. Endocytosis of plasma membrane proteins results in vesicles, which fuse with the early endosome. If destined for lysosomal degradation, these proteins are packaged into intraluminal vesicles, converting an early endosome to a late endosome, which finally fuses with the lysosome. Each of these organelles has a unique membrane surface composition, which can form segmented membrane microcompartments by membrane contact sites or fission proteins. Furthermore, these organelles are in continuous exchange due to fission and fusion events. The underlying machinery, which maintains organelle identity along the pathway, is regulated by signaling processes. Here, we will focus on the Rab5 and Rab7 GTPases of early and late endosomes. As molecular switches, Rabs depend on activating guanine nucleotide exchange factors (GEFs). Over the last years, we characterized the Rab7 GEF, the Mon1-Ccz1 (MC1) complex, and key Rab7 effectors, the HOPS complex and retromer. Structural and functional analyses of these complexes lead to a molecular understanding of their function in the context of organelle biogenesis.
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Affiliation(s)
- Daniel Kümmel
- Institute of Biochemistry, University of Münster , Corrensstraße 36 , D-48149 Münster , Germany
| | - Eric Herrmann
- Institute of Biochemistry, University of Münster , Corrensstraße 36 , D-48149 Münster , Germany
| | - Lars Langemeyer
- Department of Biology/Chemistry, Biochemistry section , Osnabrück University , Barbarastraße 13 , D-49076 Osnabrück , Germany
- Center of Cellular Nanoanalytics (CellNanOs) , Osnabrück University , Barbarastraße 11 , D-49076 Osnabrück , Germany
| | - Christian Ungermann
- Department of Biology/Chemistry, Biochemistry section , Osnabrück University , Barbarastraße 13 , D-49076 Osnabrück , Germany
- Center of Cellular Nanoanalytics (CellNanOs) , Osnabrück University , Barbarastraße 11 , D-49076 Osnabrück , Germany
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10
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Mew M, Caldwell KA, Caldwell GA. From bugs to bedside: functional annotation of human genetic variation for neurological disorders using invertebrate models. Hum Mol Genet 2022; 31:R37-R46. [PMID: 35994032 PMCID: PMC9585664 DOI: 10.1093/hmg/ddac203] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 08/11/2022] [Accepted: 08/17/2022] [Indexed: 02/02/2023] Open
Abstract
The exponential accumulation of DNA sequencing data has opened new avenues for discovering the causative roles of single-nucleotide polymorphisms (SNPs) in neurological diseases. The opportunities emerging from this are staggering, yet only as good as our abilities to glean insights from this surplus of information. Whereas computational biology continues to improve with respect to predictions and molecular modeling, the differences between in silico and in vivo analysis remain substantial. Invertebrate in vivo model systems represent technically advanced, experimentally mature, high-throughput, efficient and cost-effective resources for investigating a disease. With a decades-long track record of enabling investigators to discern function from DNA, fly (Drosophila) and worm (Caenorhabditis elegans) models have never been better poised to serve as living engines of discovery. Both of these animals have already proven useful in the classification of genetic variants as either pathogenic or benign across a range of neurodevelopmental and neurodegenerative disorders-including autism spectrum disorders, ciliopathies, amyotrophic lateral sclerosis, Alzheimer's and Parkinson's disease. Pathogenic SNPs typically display distinctive phenotypes in functional assays when compared with null alleles and frequently lead to protein products with gain-of-function or partial loss-of-function properties that contribute to neurological disease pathogenesis. The utility of invertebrates is logically limited by overt differences in anatomical and physiological characteristics, and also the evolutionary distance in genome structure. Nevertheless, functional annotation of disease-SNPs using invertebrate models can expedite the process of assigning cellular and organismal consequences to mutations, ascertain insights into mechanisms of action, and accelerate therapeutic target discovery and drug development for neurological conditions.
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Affiliation(s)
- Melanie Mew
- Department of Biological Sciences, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Kim A Caldwell
- Department of Biological Sciences, The University of Alabama, Tuscaloosa, AL 35487, USA
- Alabama Research Institute on Aging, The University of Alabama, Tuscaloosa, AL 35487, USA
- Center for Convergent Bioscience and Medicine, The University of Alabama, Tuscaloosa, AL 35487, USA
- Departments of Neurobiology and Neurology, Center for Neurodegeneration and Experimental Therapeutics, Nathan Shock Center of Excellence for Research in the Basic Biology of Aging, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Guy A Caldwell
- Department of Biological Sciences, The University of Alabama, Tuscaloosa, AL 35487, USA
- Center for Convergent Bioscience and Medicine, The University of Alabama, Tuscaloosa, AL 35487, USA
- Departments of Neurobiology and Neurology, Center for Neurodegeneration and Experimental Therapeutics, Nathan Shock Center of Excellence for Research in the Basic Biology of Aging, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA
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11
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Kazachkova Y. Teaching an old dog new tricks: The plant-specific role of VPS41 in vacuolar transport and development. PLANT PHYSIOLOGY 2022; 189:1186-1187. [PMID: 35460251 PMCID: PMC9237734 DOI: 10.1093/plphys/kiac186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 04/08/2022] [Indexed: 06/14/2023]
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12
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Jiang D, He Y, Zhou X, Cao Z, Pang L, Zhong S, Jiang L, Li R. Arabidopsis HOPS subunit VPS41 carries out plant-specific roles in vacuolar transport and vegetative growth. PLANT PHYSIOLOGY 2022; 189:1416-1434. [PMID: 35417008 PMCID: PMC9237685 DOI: 10.1093/plphys/kiac167] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Accepted: 02/25/2022] [Indexed: 05/27/2023]
Abstract
The homotypic fusion and protein sorting (HOPS) complex is a conserved, multi-subunit tethering complex in eukaryotic cells. In yeast and mammalian cells, the HOPS subunit vacuolar protein sorting-associated protein 41 (VPS41) is recruited to late endosomes after Ras-related protein 7 (Rab7) activation and is essential for vacuole fusion. However, whether VPS41 plays conserved roles in plants is not clear. Here, we demonstrate that in the model plant Arabidopsis (Arabidopsis thaliana), VPS41 localizes to distinct condensates in root cells in addition to its reported localization at the tonoplast. The formation of condensates does not rely on the known upstream regulators but depends on VPS41 self-interaction and is essential for vegetative growth regulation. Genetic evidence indicates that VPS41 is required for both homotypic vacuole fusion and cargo sorting from the adaptor protein complex 3, Rab5, and Golgi-independent pathways but is dispensable for the Rab7 cargo inositol transporter 1. We also show that VPS41 has HOPS-independent functions in vacuolar transport. Taken together, our findings indicate that Arabidopsis VPS41 is a unique subunit of the HOPS complex that carries out plant-specific roles in both vacuolar transport and developmental regulation.
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Affiliation(s)
- Dong Jiang
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, School of Life Sciences, Institute of Plant and Food Science, Southern University of Science and Technology, Shenzhen 518055, China
| | - Yilin He
- School of Life Sciences, Centre for Cell and Developmental Biology and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
| | - Xiangui Zhou
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, School of Life Sciences, Institute of Plant and Food Science, Southern University of Science and Technology, Shenzhen 518055, China
| | - Zhiran Cao
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, School of Life Sciences, Institute of Plant and Food Science, Southern University of Science and Technology, Shenzhen 518055, China
| | - Lei Pang
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, School of Life Sciences, Institute of Plant and Food Science, Southern University of Science and Technology, Shenzhen 518055, China
| | - Sheng Zhong
- State Key Laboratory for Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences at the College of Life Sciences, Peking University, Beijing 100871, China
| | - Liwen Jiang
- School of Life Sciences, Centre for Cell and Developmental Biology and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
- CUHK Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen 518172, China
| | - Ruixi Li
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, School of Life Sciences, Institute of Plant and Food Science, Southern University of Science and Technology, Shenzhen 518055, China
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13
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Xu H, Chang F, Jain S, Heller BA, Han X, Liu Y, Edwards RH. SNX5 targets a monoamine transporter to the TGN for assembly into dense core vesicles by AP-3. J Cell Biol 2022; 221:e202106083. [PMID: 35426896 PMCID: PMC9016777 DOI: 10.1083/jcb.202106083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 12/06/2021] [Accepted: 02/16/2022] [Indexed: 11/22/2022] Open
Abstract
The time course of signaling by peptide hormones, neural peptides, and other neuromodulators depends on their storage inside dense core vesicles (DCVs). Adaptor protein 3 (AP-3) assembles the membrane proteins that confer regulated release of DCVs and is thought to promote their trafficking from endosomes directly to maturing DCVs. We now find that regulated monoamine release from DCVs requires sorting nexin 5 (SNX5). Loss of SNX5 disrupts trafficking of the vesicular monoamine transporter (VMAT) to DCVs. The mechanism involves a role for SNX5 in retrograde transport of VMAT from endosomes to the TGN. However, this role for SNX5 conflicts with the proposed function of AP-3 in trafficking from endosomes directly to DCVs. We now identify a transient role for AP-3 at the TGN, where it associates with DCV cargo. Thus, retrograde transport from endosomes by SNX5 enables DCV assembly at the TGN by AP-3, resolving the apparent antagonism. A novel role for AP-3 at the TGN has implications for other organelles that also depend on this adaptor.
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Affiliation(s)
- Hongfei Xu
- Departments of Neurology and Physiology, University of California San Francisco, San Francisco, CA
- Jiangsu Key Laboratory of Xenotransplantation, School of Basic Medical Science, Nanjing Medical University, Nanjing, China
| | - Fei Chang
- Jiangsu Key Laboratory of Xenotransplantation, School of Basic Medical Science, Nanjing Medical University, Nanjing, China
| | - Shweta Jain
- Departments of Neurology and Physiology, University of California San Francisco, San Francisco, CA
| | - Bradley Austin Heller
- Departments of Neurology and Physiology, University of California San Francisco, San Francisco, CA
| | - Xu Han
- Jiangsu Key Laboratory of Xenotransplantation, School of Basic Medical Science, Nanjing Medical University, Nanjing, China
| | - Yongjian Liu
- Jiangsu Key Laboratory of Xenotransplantation, School of Basic Medical Science, Nanjing Medical University, Nanjing, China
- Departments of Pharmacology and Biological Chemistry, University of Pittsburgh, Pittsburgh, PA
| | - Robert H. Edwards
- Departments of Neurology and Physiology, University of California San Francisco, San Francisco, CA
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14
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Li W, Hao CJ, Hao ZH, Ma J, Wang QC, Yuan YF, Gong JJ, Chen YY, Yu JY, Wei AH. New insights into the pathogenesis of Hermansky-Pudlak syndrome. Pigment Cell Melanoma Res 2022; 35:290-302. [PMID: 35129281 DOI: 10.1111/pcmr.13030] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 02/02/2022] [Accepted: 02/03/2022] [Indexed: 12/14/2022]
Abstract
Hermansky-Pudlak syndrome (HPS) is characterized by defects of multiple tissue-specific lysosome-related organelles (LROs), typically manifesting with oculocutaneous albinism or ocular albinism, bleeding tendency, and in some cases with pulmonary fibrosis, inflammatory bowel disease or immunodeficiency, neuropsychological disorders. Eleven HPS subtypes in humans and at least 15 subtypes in mice have been molecularly identified. Current understanding of the underlying mechanisms of HPS is focusing on the defective biogenesis of LROs. Compelling evidences have shown that HPS protein-associated complexes (HPACs) function in cargo transport, cargo recycling, and cargo removal to maintain LRO homeostasis. Further investigation on the molecular and cellular mechanism of LRO biogenesis and secretion will be helpful for better understanding of its pathogenesis and for the precise intervention of HPS.
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Affiliation(s)
- Wei Li
- Beijing Key Laboratory for Genetics of Birth Defects, Beijing Pediatric Research Institute, Beijing Children's Hospital, Capital Medical University, Center of Rare Diseases, National Center for Children's Health, Beijing, China.,MOE Key Laboratory of Major Diseases in Children, Capital Medical University, Beijing, China
| | - Chan-Juan Hao
- Beijing Key Laboratory for Genetics of Birth Defects, Beijing Pediatric Research Institute, Beijing Children's Hospital, Capital Medical University, Center of Rare Diseases, National Center for Children's Health, Beijing, China.,MOE Key Laboratory of Major Diseases in Children, Capital Medical University, Beijing, China
| | - Zhen-Hua Hao
- Beijing Key Laboratory for Genetics of Birth Defects, Beijing Pediatric Research Institute, Beijing Children's Hospital, Capital Medical University, Center of Rare Diseases, National Center for Children's Health, Beijing, China.,MOE Key Laboratory of Major Diseases in Children, Capital Medical University, Beijing, China
| | - Jing Ma
- Beijing Key Laboratory for Genetics of Birth Defects, Beijing Pediatric Research Institute, Beijing Children's Hospital, Capital Medical University, Center of Rare Diseases, National Center for Children's Health, Beijing, China.,MOE Key Laboratory of Major Diseases in Children, Capital Medical University, Beijing, China
| | - Qiao-Chu Wang
- Beijing Key Laboratory for Genetics of Birth Defects, Beijing Pediatric Research Institute, Beijing Children's Hospital, Capital Medical University, Center of Rare Diseases, National Center for Children's Health, Beijing, China.,MOE Key Laboratory of Major Diseases in Children, Capital Medical University, Beijing, China
| | - Ye-Feng Yuan
- Beijing Key Laboratory for Genetics of Birth Defects, Beijing Pediatric Research Institute, Beijing Children's Hospital, Capital Medical University, Center of Rare Diseases, National Center for Children's Health, Beijing, China.,MOE Key Laboratory of Major Diseases in Children, Capital Medical University, Beijing, China
| | - Juan-Juan Gong
- Beijing Key Laboratory for Genetics of Birth Defects, Beijing Pediatric Research Institute, Beijing Children's Hospital, Capital Medical University, Center of Rare Diseases, National Center for Children's Health, Beijing, China.,MOE Key Laboratory of Major Diseases in Children, Capital Medical University, Beijing, China
| | - Yuan-Ying Chen
- Beijing Key Laboratory for Genetics of Birth Defects, Beijing Pediatric Research Institute, Beijing Children's Hospital, Capital Medical University, Center of Rare Diseases, National Center for Children's Health, Beijing, China.,MOE Key Laboratory of Major Diseases in Children, Capital Medical University, Beijing, China
| | - Jia-Ying Yu
- Beijing Key Laboratory for Genetics of Birth Defects, Beijing Pediatric Research Institute, Beijing Children's Hospital, Capital Medical University, Center of Rare Diseases, National Center for Children's Health, Beijing, China.,MOE Key Laboratory of Major Diseases in Children, Capital Medical University, Beijing, China
| | - Ai-Hua Wei
- Department of Dermatology, Tongren Hospital, Capital Medical University, Beijing, China
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15
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Ishii J, Sato-Yazawa H, Kashiwagi K, Nakadate K, Iwamoto M, Kohno K, Miyata-Hiramatsu C, Masawa M, Onozaki M, Noda S, Miyazawa T, Takagi M, Yazawa T. Endocrine secretory granule production is caused by a lack of REST and intragranular secretory content and accelerated by PROX1. J Mol Histol 2022; 53:437-448. [PMID: 35094211 PMCID: PMC9117388 DOI: 10.1007/s10735-021-10055-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Accepted: 12/23/2021] [Indexed: 12/30/2022]
Abstract
Endocrine secretory granules (ESGs) are morphological characteristics of endocrine/neuroendocrine cells and store peptide hormones/neurotransmitters. ESGs contain prohormones and ESG-related molecules, mainly chromogranin/secretogranin family proteins. However, the precise mechanism of ESG formation has not been elucidated. In this study, we experimentally induced ESGs in the non-neuroendocrine lung cancer cell line H1299. Since repressive element 1 silencing transcription factor (REST) and prospero homeobox 1 (PROX1) are closely associated with the expression of ESG-related molecules, we edited the REST gene and/or transfected PROX1 and then performed molecular biology, immunocytochemistry, and electron and immunoelectron microscopy assays to determine whether ESG-related molecules and ESGs were induced in H1299 cells. Although chromogranin/secretogranin family proteins were induced in H1299 cells by knockout of REST and the induction was accelerated by the PROX1 transgene, the ESGs could not be defined by electron microscopy. However, a small number of ESGs were detected in the H1299 cells lacking REST and expressing pro-opiomelanocortin (POMC) by electron microscopy. Furthermore, many ESGs were produced in the REST-lacking and PROX1- and POMC-expressing H1299 cells. These findings suggest that a lack of REST and the expression of genes related to ESG content are indispensable for ESG production and that PROX1 accelerates ESG production. Trial registration: Not applicable.
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Affiliation(s)
- Jun Ishii
- Department of Pathology, Dokkyo Medical University School of Medicine and Graduate School of Medicine, Mibu-machi, Tochigi, Japan
| | - Hanako Sato-Yazawa
- Department of Pathology, Dokkyo Medical University School of Medicine and Graduate School of Medicine, Mibu-machi, Tochigi, Japan
| | - Korehito Kashiwagi
- Department of Pathology, Dokkyo Medical University School of Medicine and Graduate School of Medicine, Mibu-machi, Tochigi, Japan
| | - Kazuhiko Nakadate
- Education Research Center, Meiji Pharmaceutical University, Kiyose-shi, Tokyo, Japan
| | - Masami Iwamoto
- Department of Pathology, Dokkyo Medical University School of Medicine and Graduate School of Medicine, Mibu-machi, Tochigi, Japan
- Department of Pathology, The Jikei University, Minato-ku, Tokyo, Japan
| | - Kakeru Kohno
- Department of Pathology, Dokkyo Medical University School of Medicine and Graduate School of Medicine, Mibu-machi, Tochigi, Japan
- Institute of Life Innovation Studies, Toyo University, Itakura-machi, Gunma, Japan
| | - Chie Miyata-Hiramatsu
- Department of Pathology, Dokkyo Medical University School of Medicine and Graduate School of Medicine, Mibu-machi, Tochigi, Japan
| | - Meitetsu Masawa
- Department of Respiratory Medicine, Dokkyo Medical University School of Medicine and Graduate School of Medicine, Mibu-machi, Tochigi, Japan
| | - Masato Onozaki
- Department of Diagnostic Pathology, Dokkyo Medical University School of Medicine and Graduate School of Medicine, Mibu-machi, Tochigi, Japan
| | - Shuhei Noda
- Department of Diagnostic Pathology, Dokkyo Medical University School of Medicine and Graduate School of Medicine, Mibu-machi, Tochigi, Japan
| | - Tadasuke Miyazawa
- Department of Pathology, Dokkyo Medical University School of Medicine and Graduate School of Medicine, Mibu-machi, Tochigi, Japan
| | - Megumi Takagi
- Department of Pathology, Dokkyo Medical University School of Medicine and Graduate School of Medicine, Mibu-machi, Tochigi, Japan
| | - Takuya Yazawa
- Department of Pathology, Dokkyo Medical University School of Medicine and Graduate School of Medicine, Mibu-machi, Tochigi, Japan.
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16
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Hu G, Bakkeren E, Caza M, Horianopoulos L, Sánchez-León E, Sorensen M, Jung W, Kronstad JW. Vam6/Vps39/TRAP1-domain proteins influence vacuolar morphology, iron acquisition and virulence in Cryptococcus neoformans. Cell Microbiol 2021; 23:e13400. [PMID: 34800311 DOI: 10.1111/cmi.13400] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Revised: 11/05/2021] [Accepted: 11/16/2021] [Indexed: 12/21/2022]
Abstract
The pathogenic fungus Cryptococcus neoformans must overcome iron limitation to cause disease in mammalian hosts. Previously, we reported a screen for insertion mutants with poor growth on haem as the sole iron source. In this study, we characterised one such mutant and found that the defective gene encoded a Vam6/Vps39/TRAP1 domain-containing protein required for robust growth on haem, an important iron source in host tissue. We designated this protein Vps3 based on reciprocal best matches with the corresponding protein in Saccharomyces cerevisiae. C. neoformans encodes a second Vam6/Vps39/TRAP1 domain-containing protein designated Vam6/Vlp1, and we found that this protein is also required for robust growth on haem as well as on inorganic iron sources. This protein is predicted to be a component of the homotypic fusion and vacuole protein sorting complex involved in endocytosis. Further characterisation of the vam6Δ and vps3Δ mutants revealed perturbed trafficking of iron acquisition functions (e.g., the high affinity iron permease Cft1) and impaired processing of the transcription factor Rim101, a regulator of haem and iron acquisition. The vps3Δ and vam6Δ mutants also had pleiotropic phenotypes including loss of virulence in a mouse model of cryptococcosis, reduced virulence factor elaboration and increased susceptibility to stress, indicating pleiotropic roles for Vps3 and Vam6 beyond haem use in C. neoformans. TAKE AWAYS: Two Vam6/Vps39/TRAP1-domain proteins, Vps3 and Vam6, support the growth of Cryptococcus neoformans on haem. Loss of Vps3 and Vam6 influences the trafficking and expression of iron uptake proteins. Loss of Vps3 or Vam6 eliminates the ability of C. neoformans to cause disease in a mouse model of cryptococcosis.
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Affiliation(s)
- Guanggan Hu
- The Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, Canada.,Department of Microbiology and Immunology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Erik Bakkeren
- The Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, Canada.,Department of Microbiology and Immunology, University of British Columbia, Vancouver, British Columbia, Canada.,Department of Zoology, University of Oxford, Oxford, UK
| | - Mélissa Caza
- The Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, Canada.,Department of Microbiology and Immunology, University of British Columbia, Vancouver, British Columbia, Canada.,Larissa Yarr Medical Microbiology Laboratory, Kelowna General Hospital, Kelowna, British Columbia, Canada
| | - Linda Horianopoulos
- The Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, Canada.,Department of Microbiology and Immunology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Eddy Sánchez-León
- The Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, Canada.,Department of Microbiology and Immunology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Melanie Sorensen
- The Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, Canada.,Department of Microbiology and Immunology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Wonhee Jung
- Department of Systems Biotechnology, Chung-Ang University, Anseong, Republic of Korea
| | - James W Kronstad
- The Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, Canada.,Department of Microbiology and Immunology, University of British Columbia, Vancouver, British Columbia, Canada
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17
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Schoppe J, Schubert E, Apelbaum A, Yavavli E, Birkholz O, Stephanowitz H, Han Y, Perz A, Hofnagel O, Liu F, Piehler J, Raunser S, Ungermann C. Flexible open conformation of the AP-3 complex explains its role in cargo recruitment at the Golgi. J Biol Chem 2021; 297:101334. [PMID: 34688652 PMCID: PMC8591511 DOI: 10.1016/j.jbc.2021.101334] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 09/15/2021] [Accepted: 09/21/2021] [Indexed: 01/17/2023] Open
Abstract
Vesicle formation at endomembranes requires the selective concentration of cargo by coat proteins. Conserved adapter protein complexes at the Golgi (AP-3), the endosome (AP-1), or the plasma membrane (AP-2) with their conserved core domain and flexible ear domains mediate this function. These complexes also rely on the small GTPase Arf1 and/or specific phosphoinositides for membrane binding. The structural details that influence these processes, however, are still poorly understood. Here we present cryo-EM structures of the full-length stable 300 kDa yeast AP-3 complex. The structures reveal that AP-3 adopts an open conformation in solution, comparable to the membrane-bound conformations of AP-1 or AP-2. This open conformation appears to be far more flexible than AP-1 or AP-2, resulting in compact, intermediate, and stretched subconformations. Mass spectrometrical analysis of the cross-linked AP-3 complex further indicates that the ear domains are flexibly attached to the surface of the complex. Using biochemical reconstitution assays, we also show that efficient AP-3 recruitment to the membrane depends primarily on cargo binding. Once bound to cargo, AP-3 clustered and immobilized cargo molecules, as revealed by single-molecule imaging on polymer-supported membranes. We conclude that its flexible open state may enable AP-3 to bind and collect cargo at the Golgi and could thus allow coordinated vesicle formation at the trans-Golgi upon Arf1 activation.
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Affiliation(s)
- Jannis Schoppe
- Department of Biology/Chemistry, Biochemistry Section, Osnabrück University, Osnabrück, Germany
| | - Evelyn Schubert
- Department of Structural Biochemistry, Max-Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Amir Apelbaum
- Department of Structural Biochemistry, Max-Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Erdal Yavavli
- Department of Biology/Chemistry, Biochemistry Section, Osnabrück University, Osnabrück, Germany
| | - Oliver Birkholz
- Department of Biology/Chemistry, Biophysics Section, Osnabrück University, Osnabrück, Germany
| | - Heike Stephanowitz
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Campus Berlin-Buch, Berlin, Germany
| | - Yaping Han
- Department of Biology/Chemistry, Biochemistry Section, Osnabrück University, Osnabrück, Germany
| | - Angela Perz
- Department of Biology/Chemistry, Biochemistry Section, Osnabrück University, Osnabrück, Germany
| | - Oliver Hofnagel
- Department of Structural Biochemistry, Max-Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Fan Liu
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Campus Berlin-Buch, Berlin, Germany
| | - Jacob Piehler
- Department of Biology/Chemistry, Biophysics Section, Osnabrück University, Osnabrück, Germany; Center of Cellular Nanoanalytics Osnabrück (CellNanOs), Osnabrück University, Osnabrück, Germany
| | - Stefan Raunser
- Department of Structural Biochemistry, Max-Planck Institute of Molecular Physiology, Dortmund, Germany.
| | - Christian Ungermann
- Department of Biology/Chemistry, Biochemistry Section, Osnabrück University, Osnabrück, Germany; Center of Cellular Nanoanalytics Osnabrück (CellNanOs), Osnabrück University, Osnabrück, Germany.
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18
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Jewett CE, Soh AWJ, Lin CH, Lu Q, Lencer E, Westlake CJ, Pearson CG, Prekeris R. RAB19 Directs Cortical Remodeling and Membrane Growth for Primary Ciliogenesis. Dev Cell 2021; 56:325-340.e8. [PMID: 33561422 DOI: 10.1016/j.devcel.2020.12.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Revised: 10/09/2020] [Accepted: 12/07/2020] [Indexed: 12/14/2022]
Abstract
Primary cilia are sensory organelles that utilize the compartmentalization of membrane and cytoplasm to communicate signaling events, and yet, how the formation of a cilium is coordinated with reorganization of the cortical membrane and cytoskeleton is unclear. Using polarized epithelia, we find that cortical actin clearing and apical membrane partitioning occur where the centrosome resides at the cell surface prior to ciliation. RAB19, a previously uncharacterized RAB, associates with the RAB-GAP TBC1D4 and the HOPS-tethering complex to coordinate cortical clearing and ciliary membrane growth, which is essential for ciliogenesis. This RAB19-directed pathway is not exclusive to polarized epithelia, as RAB19 loss in nonpolarized cell types blocks ciliogenesis with a docked ciliary vesicle. Remarkably, inhibiting actomyosin contractility can substitute for the function of the RAB19 complex and restore ciliogenesis in knockout cells. Together, this work provides a mechanistic understanding behind a cytoskeletal clearing and membrane partitioning step required for ciliogenesis.
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Affiliation(s)
- Cayla E Jewett
- Department of Cell and Developmental Biology, University of Colorado, Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Adam W J Soh
- Department of Cell and Developmental Biology, University of Colorado, Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Carrie H Lin
- Department of Cell and Developmental Biology, University of Colorado, Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Quanlong Lu
- Laboratory of Cell and Developmental Signaling, National Cancer Institute-Frederick, Frederick, MD 21702, USA
| | - Ezra Lencer
- Department of Cell and Developmental Biology, University of Colorado, Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Christopher J Westlake
- Laboratory of Cell and Developmental Signaling, National Cancer Institute-Frederick, Frederick, MD 21702, USA
| | - Chad G Pearson
- Department of Cell and Developmental Biology, University of Colorado, Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Rytis Prekeris
- Department of Cell and Developmental Biology, University of Colorado, Anschutz Medical Campus, Aurora, CO 80045, USA.
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19
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van der Welle REN, Jobling R, Burns C, Sanza P, van der Beek JA, Fasano A, Chen L, Zwartkruis FJ, Zwakenberg S, Griffin EF, ten Brink C, Veenendaal T, Liv N, van Ravenswaaij‐Arts CMA, Lemmink HH, Pfundt R, Blaser S, Sepulveda C, Lozano AM, Yoon G, Santiago‐Sim T, Asensio CS, Caldwell GA, Caldwell KA, Chitayat D, Klumperman J. Neurodegenerative VPS41 variants inhibit HOPS function and mTORC1-dependent TFEB/TFE3 regulation. EMBO Mol Med 2021; 13:e13258. [PMID: 33851776 PMCID: PMC8103106 DOI: 10.15252/emmm.202013258] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 02/19/2021] [Accepted: 02/22/2021] [Indexed: 11/09/2022] Open
Abstract
Vacuolar protein sorting 41 (VPS41) is as part of the Homotypic fusion and Protein Sorting (HOPS) complex required for lysosomal fusion events and, independent of HOPS, for regulated secretion. Here, we report three patients with compound heterozygous mutations in VPS41 (VPS41S285P and VPS41R662* ; VPS41c.1423-2A>G and VPS41R662* ) displaying neurodegeneration with ataxia and dystonia. Cellular consequences were investigated in patient fibroblasts and VPS41-depleted HeLa cells. All mutants prevented formation of a functional HOPS complex, causing delayed lysosomal delivery of endocytic and autophagic cargo. By contrast, VPS41S285P enabled regulated secretion. Strikingly, loss of VPS41 function caused a cytosolic redistribution of mTORC1, continuous nuclear localization of Transcription Factor E3 (TFE3), enhanced levels of LC3II, and a reduced autophagic response to nutrient starvation. Phosphorylation of mTORC1 substrates S6K1 and 4EBP1 was not affected. In a C. elegans model of Parkinson's disease, co-expression of VPS41S285P /VPS41R662* abolished the neuroprotective function of VPS41 against α-synuclein aggregates. We conclude that the VPS41 variants specifically abrogate HOPS function, which interferes with the TFEB/TFE3 axis of mTORC1 signaling, and cause a neurodegenerative disease.
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Affiliation(s)
- Reini E N van der Welle
- Section Cell BiologyCenter for Molecular MedicineInstitute of BiomembranesUniversity Medical Center UtrechtUtrecht UniversityUtrechtThe Netherlands
| | - Rebekah Jobling
- Department of PediatricsDivision of Clinical and Metabolic GeneticsThe Hospital for Sick ChildrenUniversity of TorontoTorontoONCanada
| | - Christian Burns
- Department of Biological SciencesDivision of Natural Sciences and MathematicsUniversity of DenverDenverCOUSA
| | - Paolo Sanza
- Section Cell BiologyCenter for Molecular MedicineInstitute of BiomembranesUniversity Medical Center UtrechtUtrecht UniversityUtrechtThe Netherlands
| | - Jan A van der Beek
- Section Cell BiologyCenter for Molecular MedicineInstitute of BiomembranesUniversity Medical Center UtrechtUtrecht UniversityUtrechtThe Netherlands
| | - Alfonso Fasano
- Edmond J. Safra Program in Parkinson’s DiseaseMorton and Gloria Shulman Movement Disorders ClinicToronto Western Hospital, UHNTorontoONCanada
- Division of NeurologyUniversity of TorontoTorontoONCanada
- Krembil Brain InstituteTorontoONCanada
- Center for Advancing Neurotechnological Innovation to Application (CRANIA)TorontoONCanada
| | - Lan Chen
- Department of Biological SciencesDivision of Natural Sciences and MathematicsUniversity of DenverDenverCOUSA
| | - Fried J Zwartkruis
- Section Molecular Cancer ResearchCenter for Molecular MedicineUniversity Medical Center UtrechtUtrecht UniversityUtrechtThe Netherlands
| | - Susan Zwakenberg
- Section Molecular Cancer ResearchCenter for Molecular MedicineUniversity Medical Center UtrechtUtrecht UniversityUtrechtThe Netherlands
| | - Edward F Griffin
- Department of Biological SciencesThe University of AlabamaTuscaloosaALUSA
- Department of NeurologyCenter for Neurodegeneration and Experimental TherapeuticsNathan Shock Center for Basic Research in the Biology of AgingUniversity of Alabama at Birmingham School of MedicineBirminghamALUSA
| | - Corlinda ten Brink
- Section Cell BiologyCenter for Molecular MedicineInstitute of BiomembranesUniversity Medical Center UtrechtUtrecht UniversityUtrechtThe Netherlands
| | - Tineke Veenendaal
- Section Cell BiologyCenter for Molecular MedicineInstitute of BiomembranesUniversity Medical Center UtrechtUtrecht UniversityUtrechtThe Netherlands
| | - Nalan Liv
- Section Cell BiologyCenter for Molecular MedicineInstitute of BiomembranesUniversity Medical Center UtrechtUtrecht UniversityUtrechtThe Netherlands
| | | | - Henny H Lemmink
- Department of GeneticsUniversity Medical Center GroningenUniversity of GroningenGroningenThe Netherlands
| | - Rolph Pfundt
- Department of Human GeneticsRadboud University Medical CenterNijmegenThe Netherlands
| | - Susan Blaser
- Department of Diagnostic ImagingHospital for Sick ChildrenTorontoONCanada
| | - Carolina Sepulveda
- Edmond J. Safra Program in Parkinson’s DiseaseMorton and Gloria Shulman Movement Disorders ClinicToronto Western Hospital, UHNTorontoONCanada
- Division of NeurologyUniversity of TorontoTorontoONCanada
| | - Andres M Lozano
- Krembil Brain InstituteTorontoONCanada
- Center for Advancing Neurotechnological Innovation to Application (CRANIA)TorontoONCanada
- Department of NeurosurgeryToronto Western Hospital, UHNTorontoONCanada
- University of TorontoTorontoONCanada
| | - Grace Yoon
- Department of PediatricsDivision of Clinical and Metabolic GeneticsThe Hospital for Sick ChildrenUniversity of TorontoTorontoONCanada
| | | | - Cedric S Asensio
- Department of Biological SciencesDivision of Natural Sciences and MathematicsUniversity of DenverDenverCOUSA
| | - Guy A Caldwell
- Department of Biological SciencesThe University of AlabamaTuscaloosaALUSA
- Department of NeurologyCenter for Neurodegeneration and Experimental TherapeuticsNathan Shock Center for Basic Research in the Biology of AgingUniversity of Alabama at Birmingham School of MedicineBirminghamALUSA
| | - Kim A Caldwell
- Department of Biological SciencesThe University of AlabamaTuscaloosaALUSA
- Department of NeurologyCenter for Neurodegeneration and Experimental TherapeuticsNathan Shock Center for Basic Research in the Biology of AgingUniversity of Alabama at Birmingham School of MedicineBirminghamALUSA
| | - David Chitayat
- Department of PediatricsDivision of Clinical and Metabolic GeneticsThe Hospital for Sick ChildrenUniversity of TorontoTorontoONCanada
- The Prenatal Diagnosis and Medical Genetics ProgramDepartment of Obstetrics and GynecologyUniversity of TorontoTorontoONCanada
| | - Judith Klumperman
- Section Cell BiologyCenter for Molecular MedicineInstitute of BiomembranesUniversity Medical Center UtrechtUtrecht UniversityUtrechtThe Netherlands
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20
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Lund VK, Lycas MD, Schack A, Andersen RC, Gether U, Kjaerulff O. Rab2 drives axonal transport of dense core vesicles and lysosomal organelles. Cell Rep 2021; 35:108973. [PMID: 33852866 DOI: 10.1016/j.celrep.2021.108973] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 02/10/2021] [Accepted: 03/19/2021] [Indexed: 12/18/2022] Open
Abstract
Fast axonal transport of neuropeptide-containing dense core vesicles (DCVs), endolysosomal organelles, and presynaptic components is critical for maintaining neuronal functionality. How the transport of DCVs is orchestrated remains an important unresolved question. The small GTPase Rab2 mediates DCV biogenesis and endosome-lysosome fusion. Here, we use Drosophila to demonstrate that Rab2 also plays a critical role in bidirectional axonal transport of DCVs, endosomes, and lysosomal organelles, most likely by controlling molecular motors. We further show that the lysosomal motility factor Arl8 is required as well for axonal transport of DCVs, but unlike Rab2, it is also critical for DCV exit from cell bodies into axons. We also provide evidence that the upstream regulators of Rab2 and Arl8, Ema and BORC, activate these GTPases during DCV transport. Our results uncover the mechanisms underlying axonal transport of DCVs and reveal surprising parallels between the regulation of DCV and lysosomal motility.
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Affiliation(s)
- Viktor Karlovich Lund
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen N, Denmark
| | - Matthew Domenic Lycas
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen N, Denmark
| | - Anders Schack
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen N, Denmark
| | - Rita Chan Andersen
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen N, Denmark
| | - Ulrik Gether
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen N, Denmark
| | - Ole Kjaerulff
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen N, Denmark.
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21
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Ma CIJ, Burgess J, Brill JA. Maturing secretory granules: Where secretory and endocytic pathways converge. Adv Biol Regul 2021; 80:100807. [PMID: 33866198 DOI: 10.1016/j.jbior.2021.100807] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 03/10/2021] [Accepted: 03/18/2021] [Indexed: 10/21/2022]
Abstract
Secretory granules (SGs) are specialized organelles responsible for the storage and regulated release of various biologically active molecules from the endocrine and exocrine systems. Thus, proper SG biogenesis is critical to normal animal physiology. Biogenesis of SGs starts at the trans-Golgi network (TGN), where immature SGs (iSGs) bud off and undergo maturation before fusing with the plasma membrane (PM). How iSGs mature is unclear, but emerging studies have suggested an important role for the endocytic pathway. The requirement for endocytic machinery in SG maturation blurs the line between SGs and another class of secretory organelles called lysosome-related organelles (LROs). Therefore, it is important to re-evaluate the differences and similarities between SGs and LROs.
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Affiliation(s)
- Cheng-I Jonathan Ma
- Cell Biology Program, The Hospital for Sick Children, PGCRL Building, Room 15.9716, 686 Bay Street, Toronto, Ontario, M5G 0A4, Canada; Institute of Medical Science, University of Toronto, Medical Sciences Building, Room 2374, 1 King's College Circle, Toronto, Ontario, M5S 1A8, Canada
| | - Jason Burgess
- Cell Biology Program, The Hospital for Sick Children, PGCRL Building, Room 15.9716, 686 Bay Street, Toronto, Ontario, M5G 0A4, Canada; Department of Molecular Genetics, University of Toronto, Medical Sciences Building, Room 4396, 1 King's College Circle, Toronto, Ontario, M5S 1A8, Canada
| | - Julie A Brill
- Cell Biology Program, The Hospital for Sick Children, PGCRL Building, Room 15.9716, 686 Bay Street, Toronto, Ontario, M5G 0A4, Canada; Institute of Medical Science, University of Toronto, Medical Sciences Building, Room 2374, 1 King's College Circle, Toronto, Ontario, M5S 1A8, Canada; Department of Molecular Genetics, University of Toronto, Medical Sciences Building, Room 4396, 1 King's College Circle, Toronto, Ontario, M5S 1A8, Canada.
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22
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Burns CH, Yau B, Rodriguez A, Triplett J, Maslar D, An YS, van der Welle REN, Kossina RG, Fisher MR, Strout GW, Bayguinov PO, Veenendaal T, Chitayat D, Fitzpatrick JAJ, Klumperman J, Kebede MA, Asensio CS. Pancreatic β-Cell-Specific Deletion of VPS41 Causes Diabetes Due to Defects in Insulin Secretion. Diabetes 2021; 70:436-448. [PMID: 33168621 PMCID: PMC7881869 DOI: 10.2337/db20-0454] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Accepted: 11/03/2020] [Indexed: 12/14/2022]
Abstract
Insulin secretory granules (SGs) mediate the regulated secretion of insulin, which is essential for glucose homeostasis. The basic machinery responsible for this regulated exocytosis consists of specific proteins present both at the plasma membrane and on insulin SGs. The protein composition of insulin SGs thus dictates their release properties, yet the mechanisms controlling insulin SG formation, which determine this molecular composition, remain poorly understood. VPS41, a component of the endolysosomal tethering homotypic fusion and vacuole protein sorting (HOPS) complex, was recently identified as a cytosolic factor involved in the formation of neuroendocrine and neuronal granules. We now find that VPS41 is required for insulin SG biogenesis and regulated insulin secretion. Loss of VPS41 in pancreatic β-cells leads to a reduction in insulin SG number, changes in their transmembrane protein composition, and defects in granule-regulated exocytosis. Exploring a human point mutation, identified in patients with neurological but no endocrine defects, we show that the effect on SG formation is independent of HOPS complex formation. Finally, we report that mice with a deletion of VPS41 specifically in β-cells develop diabetes due to severe depletion of insulin SG content and a defect in insulin secretion. In sum, our data demonstrate that VPS41 contributes to glucose homeostasis and metabolism.
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Affiliation(s)
| | - Belinda Yau
- Discipline of Physiology, School of Medical Sciences, Charles Perkins Centre, The University of Sydney, Camperdown, New South Wales, Australia
| | | | - Jenna Triplett
- Department of Biological Sciences, University of Denver, Denver, CO
| | - Drew Maslar
- Department of Biological Sciences, University of Denver, Denver, CO
| | - You Sun An
- Discipline of Physiology, School of Medical Sciences, Charles Perkins Centre, The University of Sydney, Camperdown, New South Wales, Australia
| | - Reini E N van der Welle
- Section of Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Ross G Kossina
- Washington University Center for Cellular Imaging, Washington University School of Medicine, St. Louis, MO
| | - Max R Fisher
- Washington University Center for Cellular Imaging, Washington University School of Medicine, St. Louis, MO
| | - Gregory W Strout
- Washington University Center for Cellular Imaging, Washington University School of Medicine, St. Louis, MO
| | - Peter O Bayguinov
- Washington University Center for Cellular Imaging, Washington University School of Medicine, St. Louis, MO
| | - Tineke Veenendaal
- Section of Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - David Chitayat
- Division of Clinical and Metabolic Genetics, Department of Pediatrics, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
- Prenatal Diagnosis and Medical Genetics Program, Department of Obstetrics and Gynaecology, University of Toronto, Toronto, Ontario, Canada
| | - James A J Fitzpatrick
- Washington University Center for Cellular Imaging, Washington University School of Medicine, St. Louis, MO
- Departments of Neuroscience and Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO
| | - Judith Klumperman
- Section of Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Melkam A Kebede
- Discipline of Physiology, School of Medical Sciences, Charles Perkins Centre, The University of Sydney, Camperdown, New South Wales, Australia
| | - Cedric S Asensio
- Department of Biological Sciences, University of Denver, Denver, CO
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23
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Rizalar FS, Roosen DA, Haucke V. A Presynaptic Perspective on Transport and Assembly Mechanisms for Synapse Formation. Neuron 2020; 109:27-41. [PMID: 33098763 DOI: 10.1016/j.neuron.2020.09.038] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 08/26/2020] [Accepted: 09/25/2020] [Indexed: 01/01/2023]
Abstract
Neurons are highly polarized cells with a single axon and multiple dendrites derived from the cell body to form tightly associated pre- and postsynaptic compartments. As the biosynthetic machinery is largely restricted to the somatodendritic domain, the vast majority of presynaptic components are synthesized in the neuronal soma, packaged into synaptic precursor vesicles, and actively transported along the axon to sites of presynaptic biogenesis. In contrast with the significant progress that has been made in understanding synaptic transmission and processing of information at the post-synapse, comparably little is known about the formation and dynamic remodeling of the presynaptic compartment. We review here our current understanding of the mechanisms that govern the biogenesis, transport, and assembly of the key components for presynaptic neurotransmission, discuss how alterations in presynaptic assembly may impact nervous system function or lead to disease, and outline key open questions for future research.
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Affiliation(s)
- Filiz Sila Rizalar
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Berlin, Germany
| | - Dorien A Roosen
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Berlin, Germany
| | - Volker Haucke
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Berlin, Germany; Faculty of Biology, Chemistry, Pharmacy, Freie Universität Berlin, 14195 Berlin, Germany.
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24
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Ma CIJ, Yang Y, Kim T, Chen CH, Polevoy G, Vissa M, Burgess J, Brill JA. An early endosome-derived retrograde trafficking pathway promotes secretory granule maturation. J Cell Biol 2020; 219:133712. [PMID: 32045479 PMCID: PMC7055004 DOI: 10.1083/jcb.201808017] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Revised: 11/30/2019] [Accepted: 12/20/2019] [Indexed: 02/08/2023] Open
Abstract
Regulated secretion is a fundamental cellular process in which biologically active molecules stored in long-lasting secretory granules (SGs) are secreted in response to external stimuli. Many studies have described mechanisms responsible for biogenesis and secretion of SGs, but how SGs mature remains poorly understood. In a genetic screen, we discovered a large number of endolysosomal trafficking genes required for proper SG maturation, indicating that maturation of SGs might occur in a manner similar to lysosome-related organelles (LROs). CD63, a tetraspanin known to decorate LROs, also decorates SG membranes and facilitates SG maturation. Moreover, CD63-mediated SG maturation requires type II phosphatidylinositol 4 kinase (PI4KII)-dependent early endosomal sorting and accumulation of phosphatidylinositol 4-phosphate (PI4P) on SG membranes. In addition, the PI4P effector Past1 is needed for formation of stable PI4KII-containing endosomal tubules associated with this process. Our results reveal that maturation of post-Golgi-derived SGs requires trafficking via the endosomal system, similar to mechanisms employed by LROs.
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Affiliation(s)
- Cheng-I J Ma
- Cell Biology Program, The Hospital for Sick Children, Toronto, ON, Canada.,Institute of Medical Science, University of Toronto, Toronto, ON, Canada
| | - Yitong Yang
- Cell Biology Program, The Hospital for Sick Children, Toronto, ON, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
| | - Taeah Kim
- Cell Biology Program, The Hospital for Sick Children, Toronto, ON, Canada.,Human Biology Program, University of Toronto, Toronto, ON, Canada
| | - Chang Hua Chen
- Cell Biology Program, The Hospital for Sick Children, Toronto, ON, Canada.,Human Biology Program, University of Toronto, Toronto, ON, Canada
| | - Gordon Polevoy
- Cell Biology Program, The Hospital for Sick Children, Toronto, ON, Canada
| | - Miluska Vissa
- Cell Biology Program, The Hospital for Sick Children, Toronto, ON, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
| | - Jason Burgess
- Cell Biology Program, The Hospital for Sick Children, Toronto, ON, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
| | - Julie A Brill
- Cell Biology Program, The Hospital for Sick Children, Toronto, ON, Canada.,Institute of Medical Science, University of Toronto, Toronto, ON, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
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25
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Schoppe J, Mari M, Yavavli E, Auffarth K, Cabrera M, Walter S, Fröhlich F, Ungermann C. AP-3 vesicle uncoating occurs after HOPS-dependent vacuole tethering. EMBO J 2020; 39:e105117. [PMID: 32840906 PMCID: PMC7560216 DOI: 10.15252/embj.2020105117] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 07/16/2020] [Accepted: 07/22/2020] [Indexed: 11/09/2022] Open
Abstract
Heterotetrameric adapter (AP) complexes cooperate with the small GTPase Arf1 or lipids in cargo selection, vesicle formation, and budding at endomembranes in eukaryotic cells. While most AP complexes also require clathrin as the outer vesicle shell, formation of AP-3-coated vesicles involved in Golgi-to-vacuole transport in yeast has been postulated to depend on Vps41, a subunit of the vacuolar HOPS tethering complex. HOPS has also been identified as the tether of AP-3 vesicles on vacuoles. To unravel this conundrum of a dual Vps41 function, we anchored Vps41 stably to the mitochondrial outer membrane. By monitoring AP-3 recruitment, we now show that Vps41 can tether AP-3 vesicles to mitochondria, yet AP-3 vesicles can form in the absence of Vps41 or clathrin. By proximity labeling and mass spectrometry, we identify the Arf1 GTPase-activating protein (GAP) Age2 at the AP-3 coat and show that tethering, but not fusion at the vacuole can occur without complete uncoating. We conclude that AP-3 vesicles retain their coat after budding and that their complete uncoating occurs only after tethering at the vacuole.
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Affiliation(s)
- Jannis Schoppe
- Department of Biology/Chemistry, Biochemistry Section, University of Osnabrück, Osnabrück, Germany
| | - Muriel Mari
- Department of Biomedical Sciences of Cells and Systems, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Erdal Yavavli
- Department of Biology/Chemistry, Biochemistry Section, University of Osnabrück, Osnabrück, Germany
| | - Kathrin Auffarth
- Department of Biology/Chemistry, Biochemistry Section, University of Osnabrück, Osnabrück, Germany
| | - Margarita Cabrera
- Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Farba, Barcelona, Spain
| | - Stefan Walter
- Center of Cellular Nanoanalytic Osnabrück (CellNanOs), University of Osnabrück, Osnabrück, Germany
| | - Florian Fröhlich
- Center of Cellular Nanoanalytic Osnabrück (CellNanOs), University of Osnabrück, Osnabrück, Germany.,Department of Biology/Chemistry, Molecular Membrane Biology Section, University of Osnabrück, Osnabrück, Germany
| | - Christian Ungermann
- Department of Biology/Chemistry, Biochemistry Section, University of Osnabrück, Osnabrück, Germany.,Center of Cellular Nanoanalytic Osnabrück (CellNanOs), University of Osnabrück, Osnabrück, Germany
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26
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Cargo Release from Myosin V Requires the Convergence of Parallel Pathways that Phosphorylate and Ubiquitylate the Cargo Adaptor. Curr Biol 2020; 30:4399-4412.e7. [PMID: 32916113 DOI: 10.1016/j.cub.2020.08.062] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 07/23/2020] [Accepted: 08/17/2020] [Indexed: 11/22/2022]
Abstract
Cellular function requires molecular motors to transport cargoes to their correct intracellular locations. The regulated assembly and disassembly of motor-adaptor complexes ensures that cargoes are loaded at their origin and unloaded at their destination. In Saccharomyces cerevisiae, early in the cell cycle, a portion of the vacuole is transported into the emerging bud. This transport requires a myosin V motor, Myo2, which attaches to the vacuole via Vac17, the vacuole-specific adaptor protein. Vac17 also binds to Vac8, a vacuolar membrane protein. Once the vacuole is brought to the bud cortex via the Myo2-Vac17-Vac8 complex, Vac17 is degraded and the vacuole is released from Myo2. However, mechanisms governing dissociation of the Myo2-Vac17-Vac8 complex are not well understood. Ubiquitylation of the Vac17 adaptor at the bud cortex provides spatial regulation of vacuole release. Here, we report that ubiquitylation alone is not sufficient for cargo release. We find that a parallel pathway, which initiates on the vacuole, converges with ubiquitylation to release the vacuole from Myo2. Specifically, we show that Yck3 and Vps41, independent of their known roles in homotypic fusion and protein sorting (HOPS)-mediated vesicle tethering, are required for the phosphorylation of Vac17 in its Myo2 binding domain. These phosphorylation events allow ubiquitylated Vac17 to be released from Myo2 and Vac8. Our data suggest that Vps41 is regulating the phosphorylation of Vac17 via Yck3, a casein kinase I, and likely another unknown kinase. That parallel pathways are required to release the vacuole from Myo2 suggests that multiple signals are integrated to terminate organelle inheritance.
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27
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Sparvoli D, Zoltner M, Cheng CY, Field MC, Turkewitz AP. Diversification of CORVET tethers facilitates transport complexity in Tetrahymena thermophila. J Cell Sci 2020; 133:jcs238659. [PMID: 31964712 PMCID: PMC7033735 DOI: 10.1242/jcs.238659] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Accepted: 01/03/2020] [Indexed: 12/14/2022] Open
Abstract
In endolysosomal networks, two hetero-hexameric tethers called HOPS and CORVET are found widely throughout eukaryotes. The unicellular ciliate Tetrahymena thermophila possesses elaborate endolysosomal structures, but curiously both it and related protozoa lack the HOPS tether and several other trafficking proteins, while retaining the related CORVET complex. Here, we show that Tetrahymena encodes multiple paralogs of most CORVET subunits, which assemble into six distinct complexes. Each complex has a unique subunit composition and, significantly, shows unique localization, indicating participation in distinct pathways. One pair of complexes differ by a single subunit (Vps8), but have late endosomal versus recycling endosome locations. While Vps8 subunits are thus prime determinants for targeting and functional specificity, determinants exist on all subunits except Vps11. This unprecedented expansion and diversification of CORVET provides a potent example of tether flexibility, and illustrates how 'backfilling' following secondary losses of trafficking genes can provide a mechanism for evolution of new pathways.This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Daniela Sparvoli
- Department of Molecular Genetics and Cell Biology, 920 E 58th Street, The University of Chicago, Chicago, IL, 60637, USA
| | - Martin Zoltner
- School of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK
| | - Chao-Yin Cheng
- Department of Molecular Genetics and Cell Biology, 920 E 58th Street, The University of Chicago, Chicago, IL, 60637, USA
| | - Mark C Field
- School of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK
- Biology Centre, Institute of Parasitology, Czech Academy of Sciences, 37005 Ceske Budejovice, Czech Republic
| | - Aaron P Turkewitz
- Department of Molecular Genetics and Cell Biology, 920 E 58th Street, The University of Chicago, Chicago, IL, 60637, USA
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28
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Hummer BH, Maslar D, Soltero-Gutierrez M, de Leeuw NF, Asensio CS. Differential sorting behavior for soluble and transmembrane cargoes at the trans-Golgi network in endocrine cells. Mol Biol Cell 2019; 31:157-166. [PMID: 31825717 PMCID: PMC7001476 DOI: 10.1091/mbc.e19-10-0561] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Regulated secretion of neuropeptides and peptide hormones by secretory granules (SGs) is central to physiology. Formation of SGs occurs at the trans-Golgi network (TGN) where their soluble cargo aggregates to form a dense core, but the mechanisms controlling the sorting of regulated secretory cargoes (soluble and transmembrane) away from constitutively secreted proteins remain unclear. Optimizing the use of the retention using selective hooks method in (neuro-)endocrine cells, we now quantify TGN budding kinetics of constitutive and regulated secretory cargoes. We further show that, by monitoring two cargoes simultaneously, it becomes possible to visualize sorting to the constitutive and regulated secretory pathways in real time. Further analysis of the localization of SG cargoes immediately after budding from the TGN revealed that, surprisingly, the bulk of two studied transmembrane SG cargoes (phogrin and VMAT2) does not sort directly onto SGs during budding, but rather exit the TGN into nonregulated vesicles to get incorporated to SGs at a later step. This differential behavior of soluble and transmembrane cargoes suggests a more complex model of SG biogenesis than anticipated.
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Affiliation(s)
| | | | | | - Noah F de Leeuw
- Department of Physics and Astronomy, University of Denver, Denver, CO 80210
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29
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Topalidou I, Cattin-Ortolá J, Hummer B, Asensio CS, Ailion M. EIPR1 controls dense-core vesicle cargo retention and EARP complex localization in insulin-secreting cells. Mol Biol Cell 2019; 31:59-79. [PMID: 31721635 PMCID: PMC6938272 DOI: 10.1091/mbc.e18-07-0469] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Dense-core vesicles (DCVs) are secretory vesicles found in neurons and endocrine cells. DCVs package and release cargoes including neuropeptides, biogenic amines, and peptide hormones. We recently identified the endosome-associated recycling protein (EARP) complex and the EARP-interacting-protein EIPR-1 as proteins important for controlling levels of DCV cargoes in Caenorhabditis elegans neurons. Here we determine the role of mammalian EIPR1 in insulinoma cells. We find that in Eipr1 KO cells, there is reduced insulin secretion, and mature DCV cargoes such as insulin and carboxypeptidase E (CPE) accumulate near the trans-Golgi network and are not retained in mature DCVs in the cell periphery. In addition, we find that EIPR1 is required for the stability of the EARP complex subunits and for the localization of EARP and its association with membranes, but EIPR1 does not affect localization or function of the related Golgi-associated retrograde protein (GARP) complex. EARP is localized to two distinct compartments related to its function: an endosomal compartment and a DCV biogenesis-related compartment. We propose that EIPR1 functions with EARP to control both endocytic recycling and DCV maturation.
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Affiliation(s)
- Irini Topalidou
- Department of Biochemistry, University of Washington, Seattle, WA 98195
| | | | - Blake Hummer
- Department of Biological Sciences, University of Denver, Denver, CO 80210
| | - Cedric S Asensio
- Department of Biological Sciences, University of Denver, Denver, CO 80210
| | - Michael Ailion
- Department of Biochemistry, University of Washington, Seattle, WA 98195
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30
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Emperador-Melero J, Toonen RF, Verhage M. Vti Proteins: Beyond Endolysosomal Trafficking. Neuroscience 2019; 420:32-40. [DOI: 10.1016/j.neuroscience.2018.11.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Revised: 11/08/2018] [Accepted: 11/09/2018] [Indexed: 10/27/2022]
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31
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Abstract
Protein coats are supramolecular complexes that assemble on the cytosolic face of membranes to promote cargo sorting and transport carrier formation in the endomembrane system of eukaryotic cells. Several types of protein coats have been described, including COPI, COPII, AP-1, AP-2, AP-3, AP-4, AP-5, and retromer, which operate at different stages of the endomembrane system. Defects in these coats impair specific transport pathways, compromising the function and viability of the cells. In humans, mutations in subunits of these coats cause various congenital diseases that are collectively referred to as coatopathies. In this article, we review the fundamental properties of protein coats and the diseases that result from mutation of their constituent subunits.
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Affiliation(s)
- Esteban C Dell'Angelica
- Department of Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, California 90095, USA
| | - Juan S Bonifacino
- Cell Biology and Neurobiology Branch, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health, Bethesda, Maryland 20892, USA;
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32
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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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Pascual L, Yan J, Pujol M, Monforte AJ, Picó B, Martín-Hernández AM. CmVPS41 Is a General Gatekeeper for Resistance to Cucumber Mosaic Virus Phloem Entry in Melon. FRONTIERS IN PLANT SCIENCE 2019; 10:1219. [PMID: 31632432 PMCID: PMC6781857 DOI: 10.3389/fpls.2019.01219] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Accepted: 09/04/2019] [Indexed: 05/19/2023]
Abstract
Melon production is often compromised by viral diseases, which cannot be treated with chemicals. Therefore, the use of genetic resistances is the main strategy for generating crops resistant to viruses. Resistance to Cucumber mosaic virus (CMV) in melon is scarcely described in few accessions. Until recently, the only known resistant accessions were Freeman's Cucumber and PI 161375, cultivar Songwhan Charmi (SC). Resistance to CMV in melon is recessive and generally oligogenic and quantitative. However, in SC, the resistance to CMV strains of subgroup II is monogenic, depending only on one gene, cmv1, which is able to stop CMV movement by restricting the virus to the bundle sheath cells and preventing a systemic infection. This restriction depends on the viral movement protein (MP). Chimeric viruses carrying the MP of subgroup II strains, like the strain LS (CMV-LS), are restricted in the bundle sheath cells, whereas those carrying MP from subgroup I, like the strain FNY (CMV-FNY), are able to overcome this restriction. cmv1 encodes a vacuolar protein sorting 41 (CmVPS41), a protein involved in the transport of cargo proteins from the Golgi to the vacuole through late endosomes. We have analyzed the variability of the gene CmVPS41 in a set of 52 melon accessions belonging to 15 melon groups, both from the spp melo and the spp agrestis. We have identified 16 different haplotypes, encoding 12 different CmVPS41 protein variants. Challenging members of all haplotypes with CMV-LS, we have identified nine new resistant accessions. The resistance correlates with the presence of two mutations, either L348R, previously found in the accession SC and present in other three melon genotypes, or G85E, present in Freeman's Cucumber and found also in four additional melon genotypes. Moreover, the new resistant accessions belong to three different melon horticultural groups, Conomon, Makuwa, and Dudaim. In the new resistant accessions, the virus was able to replicate and move cell to cell, but was not able to reach the phloem. Therefore, resistance to phloem entry seems to be a general strategy in melon controlled by CmVPS41. Finally, the newly reported resistant accessions broaden the possibilities for the use of genetic resistances in new melon breeding strategies.
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Affiliation(s)
- Laura Pascual
- Centre for Research in Agricultural Genomics (CRAG) CSIC-IRTA-UAB-UB, C/Vall Moronta, Edifici CRAG, Bellaterra (Cerdanyola del Vallés), Barcelona, Spain
| | - Jinqiang Yan
- Centre for Research in Agricultural Genomics (CRAG) CSIC-IRTA-UAB-UB, C/Vall Moronta, Edifici CRAG, Bellaterra (Cerdanyola del Vallés), Barcelona, Spain
| | - Marta Pujol
- Centre for Research in Agricultural Genomics (CRAG) CSIC-IRTA-UAB-UB, C/Vall Moronta, Edifici CRAG, Bellaterra (Cerdanyola del Vallés), Barcelona, Spain
- Institut de Recerca i Tecnologia Agroalimentàries (IRTA), Campus UAB, Bellaterra, Barcelona, Spain
| | - Antonio J. Monforte
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), Universitat Politècnica de València (UPV)-Consejo Superior de Investigaciones Científicas (CSIC), Valencia, Spain
| | - Belén Picó
- COMAV, Institute for the Conservation and Breeding of Agricultural Biodiversity, Universitat Politècnica de València (UPV), Camino de Vera s/n, Valencia, Spain
| | - Ana Montserrat Martín-Hernández
- Centre for Research in Agricultural Genomics (CRAG) CSIC-IRTA-UAB-UB, C/Vall Moronta, Edifici CRAG, Bellaterra (Cerdanyola del Vallés), Barcelona, Spain
- Institut de Recerca i Tecnologia Agroalimentàries (IRTA), Campus UAB, Bellaterra, Barcelona, Spain
- *Correspondence: Ana Montserrat Martín-Hernández,
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Presynaptic Biogenesis Requires Axonal Transport of Lysosome-Related Vesicles. Neuron 2018; 99:1216-1232.e7. [DOI: 10.1016/j.neuron.2018.08.004] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Revised: 05/18/2018] [Accepted: 08/02/2018] [Indexed: 01/05/2023]
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Emperador-Melero J, Huson V, van Weering J, Bollmann C, Fischer von Mollard G, Toonen RF, Verhage M. Vti1a/b regulate synaptic vesicle and dense core vesicle secretion via protein sorting at the Golgi. Nat Commun 2018; 9:3421. [PMID: 30143604 PMCID: PMC6109172 DOI: 10.1038/s41467-018-05699-z] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Accepted: 07/19/2018] [Indexed: 12/27/2022] Open
Abstract
The SNAREs Vti1a/1b are implicated in regulated secretion, but their role relative to canonical exocytic SNAREs remains elusive. Here, we show that synaptic vesicle and dense-core vesicle (DCV) secretion is indeed severely impaired in Vti1a/b-deficient neurons. The synaptic levels of proteins that mediate secretion were reduced, down to 50% for the exocytic SNARE SNAP25. The delivery of SNAP25 and DCV-cargo into axons was decreased and these molecules accumulated in the Golgi. These defects were rescued by either Vti1a or Vti1b expression. Distended Golgi cisternae and clear vacuoles were observed in Vti1a/b-deficient neurons. The normal non-homogeneous distribution of DCV-cargo inside the Golgi was lost. Cargo trafficking out of, but not into the Golgi, was impaired. Finally, retrograde Cholera Toxin trafficking, but not Sortilin/Sorcs1 distribution, was compromised. We conclude that Vti1a/b support regulated secretion by sorting secretory cargo and synaptic secretion machinery components at the Golgi.
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Affiliation(s)
- Javier Emperador-Melero
- Departments of Functional Genomics, Clinical Genetics, VUmc, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, VU University Amsterdam and VU Medical Center, de Boelelaan 1087, 1081 HV, Amsterdam, The Netherlands
| | - Vincent Huson
- Clinical Genetics, VUmc, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, VU University Amsterdam and VU Medical Center, de Boelelaan 1087, 1081 HV, Amsterdam, The Netherlands
| | - Jan van Weering
- Clinical Genetics, VUmc, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, VU University Amsterdam and VU Medical Center, de Boelelaan 1087, 1081 HV, Amsterdam, The Netherlands
| | - Christian Bollmann
- Department of Biochemistry III, Bielefeld University, 33615, Bielefeld, Germany
| | | | - Ruud F Toonen
- Departments of Functional Genomics, Clinical Genetics, VUmc, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, VU University Amsterdam and VU Medical Center, de Boelelaan 1087, 1081 HV, Amsterdam, The Netherlands
| | - Matthijs Verhage
- Departments of Functional Genomics, Clinical Genetics, VUmc, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, VU University Amsterdam and VU Medical Center, de Boelelaan 1087, 1081 HV, Amsterdam, The Netherlands. .,Clinical Genetics, VUmc, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, VU University Amsterdam and VU Medical Center, de Boelelaan 1087, 1081 HV, Amsterdam, The Netherlands.
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36
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Bourke AM, Bowen AB, Kennedy MJ. New approaches for solving old problems in neuronal protein trafficking. Mol Cell Neurosci 2018; 91:48-66. [PMID: 29649542 DOI: 10.1016/j.mcn.2018.04.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Revised: 04/05/2018] [Accepted: 04/06/2018] [Indexed: 11/16/2022] Open
Abstract
Fundamental cellular properties are determined by the repertoire and abundance of proteins displayed on the cell surface. As such, the trafficking mechanisms for establishing and maintaining the surface proteome must be tightly regulated for cells to respond appropriately to extracellular cues, yet plastic enough to adapt to ever-changing environments. Not only are the identity and abundance of surface proteins critical, but in many cases, their regulated spatial positioning within surface nanodomains can greatly impact their function. In the context of neuronal cell biology, surface levels and positioning of ion channels and neurotransmitter receptors play essential roles in establishing important properties, including cellular excitability and synaptic strength. Here we review our current understanding of the trafficking pathways that control the abundance and localization of proteins important for synaptic function and plasticity, as well as recent technological advances that are allowing the field to investigate protein trafficking with increasing spatiotemporal precision.
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Affiliation(s)
- Ashley M Bourke
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO, United States
| | - Aaron B Bowen
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO, United States
| | - Matthew J Kennedy
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO, United States.
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Guardia CM, De Pace R, Mattera R, Bonifacino JS. Neuronal functions of adaptor complexes involved in protein sorting. Curr Opin Neurobiol 2018; 51:103-110. [PMID: 29558740 DOI: 10.1016/j.conb.2018.02.021] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Revised: 02/16/2018] [Accepted: 02/27/2018] [Indexed: 11/30/2022]
Abstract
Selective transport of transmembrane proteins to different intracellular compartments often involves the recognition of sorting signals in the cytosolic domains of the proteins by components of membrane coats. Some of these coats have as their key components a family of heterotetrameric adaptor protein (AP) complexes named AP-1 through AP-5. AP complexes play important roles in all cells, but their functions are most critical in neurons because of the extreme compartmental complexity of these cells. Accordingly, various diseases caused by mutations in AP subunit genes exhibit a range of neurological abnormalities as their most salient features. In this article, we discuss the properties of the different AP complexes, with a focus on their roles in neuronal physiology and pathology.
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Affiliation(s)
- Carlos M Guardia
- Cell Biology and Neurobiology Branch, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Raffaella De Pace
- Cell Biology and Neurobiology Branch, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Rafael Mattera
- Cell Biology and Neurobiology Branch, 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 Neurobiology Branch, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA.
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Li B, Dong X, Li X, Chen H, Zhang H, Zheng X, Zhang Z. A subunit of the HOPS endocytic tethering complex, FgVps41, is important for fungal development and plant infection in Fusarium graminearum. Environ Microbiol 2018; 20:1436-1451. [PMID: 29411478 DOI: 10.1111/1462-2920.14050] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Revised: 01/08/2018] [Accepted: 01/14/2018] [Indexed: 01/28/2023]
Abstract
The signals by which eukaryotic cells communicate with the environment are usually mediated by vesicle trafficking to be attenuated or terminated. However, vesicle trafficking-mediated signal transmission during interactions between pathogens and host plants is poorly understood. Here, we identified and characterized the vacuole sorting protein FgVps41, which is the yeast HOPS tethering complex subunit Vps41 homolog in Fusarium graminearum. Targeted gene deletion demonstrated that FgVps41 is important for vegetative growth, asexual/sexual development, conidial morphology, plant infection and deoxynivalenol production. Cellular localization and cytological examinations revealed that FgVps41 localizes to early/late endosomes and vacuole membrane, and is recruited to prevacuolar compartments and vacuole membrane by interacting with FgRab7 in F. graminearum. Furthermore, we found FgVps41 mediates vacuole membrane fusion and sorting of FgApeI, a cargo protein involving in the cytosol-to-vacuole targeting pathway. In addition, we found that FgVps41 interacts with FgYck3, a vacuolar type I casein kinase, which regulates vesicle fusion in the AP-3 pathway. Deletion of FgYck3 showed similar phenotypes to the ΔFgvps41 mutant, and both FgRab7 and FgYck3 regulate the normal localization of FgVps41. Collectively, our results demonstrate that FgVps41 acts as a HOPS tethering complex subunit and is important for the development of infection-related morphogenesis in F. graminearum.
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Affiliation(s)
- Bing Li
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, and Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing 210095, China
| | - Xin Dong
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, and Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing 210095, China
| | - Xinrui Li
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, and Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing 210095, China
| | - Huaigu Chen
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
| | - Haifeng Zhang
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, and Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing 210095, China
| | - Xiaobo Zheng
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, and Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing 210095, China
| | - Zhengguang Zhang
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, and Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing 210095, China
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39
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Hummer BH, de Leeuw NF, Burns C, Chen L, Joens MS, Hosford B, Fitzpatrick JAJ, Asensio CS. HID-1 controls formation of large dense core vesicles by influencing cargo sorting and trans-Golgi network acidification. Mol Biol Cell 2017; 28:3870-3880. [PMID: 29074564 PMCID: PMC5739301 DOI: 10.1091/mbc.e17-08-0491] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Revised: 10/05/2017] [Accepted: 10/16/2017] [Indexed: 12/19/2022] Open
Abstract
The peripheral membrane protein HID-1 localizes to the trans-Golgi network, where it contributes to the formation of large dense core vesicles of neuroendocrine cells by influencing cargo sorting and trans-Golgi network acidification. Large dense core vesicles (LDCVs) mediate the regulated release of neuropeptides and peptide hormones. They form at the trans-Golgi network (TGN), where their soluble content aggregates to form a dense core, but the mechanisms controlling biogenesis are still not completely understood. Recent studies have implicated the peripheral membrane protein HID-1 in neuropeptide sorting and insulin secretion. Using CRISPR/Cas9, we generated HID-1 KO rat neuroendocrine cells, and we show that the absence of HID-1 results in specific defects in peptide hormone and monoamine storage and regulated secretion. Loss of HID-1 causes a reduction in the number of LDCVs and affects their morphology and biochemical properties, due to impaired cargo sorting and dense core formation. HID-1 KO cells also exhibit defects in TGN acidification together with mislocalization of the Golgi-enriched vacuolar H+-ATPase subunit isoform a2. We propose that HID-1 influences early steps in LDCV formation by controlling dense core formation at the TGN.
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Affiliation(s)
- Blake H Hummer
- Department of Biological Sciences, University of Denver, Denver, CO 80210
| | - Noah F de Leeuw
- Department of Biological Sciences, University of Denver, Denver, CO 80210
| | - Christian Burns
- Department of Biological Sciences, University of Denver, Denver, CO 80210
| | - Lan Chen
- Department of Biological Sciences, University of Denver, Denver, CO 80210
| | - Matthew S Joens
- Washington University Center for Cellular Imaging, Washington University School of Medicine, St. Louis, MO 63110
| | - Bethany Hosford
- Department of Biological Sciences, University of Denver, Denver, CO 80210
| | - James A J Fitzpatrick
- Washington University Center for Cellular Imaging, Washington University School of Medicine, St. Louis, MO 63110
| | - Cedric S Asensio
- Department of Biological Sciences, University of Denver, Denver, CO 80210
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40
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Cattin-Ortolá J, Topalidou I, Dosey A, Merz AJ, Ailion M. The dense-core vesicle maturation protein CCCP-1 binds RAB-2 and membranes through its C-terminal domain. Traffic 2017; 18:720-732. [PMID: 28755404 DOI: 10.1111/tra.12507] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2017] [Revised: 07/26/2017] [Accepted: 07/26/2017] [Indexed: 12/18/2022]
Abstract
Dense-core vesicles (DCVs) are secretory organelles that store and release modulatory neurotransmitters from neurons and endocrine cells. Recently, the conserved coiled-coil protein CCCP-1 was identified as a component of the DCV biogenesis pathway in the nematode Caenorhabditis elegans. CCCP-1 binds the small GTPase RAB-2 and colocalizes with it at the trans-Golgi. Here, we report a structure-function analysis of CCCP-1 to identify domains of the protein important for its localization, binding to RAB-2, and function in DCV biogenesis. We find that the CCCP-1 C-terminal domain (CC3) has multiple activities. CC3 is necessary and sufficient for CCCP-1 localization and for binding to RAB-2, and is required for the function of CCCP-1 in DCV biogenesis. In addition, CCCP-1 binds membranes directly through its CC3 domain, indicating that CC3 may comprise a previously uncharacterized lipid-binding motif. We conclude that CCCP-1 is a coiled-coil protein that binds an activated Rab and localizes to the Golgi via its C-terminus, properties similar to members of the golgin family of proteins. CCCP-1 also shares biophysical features with golgins; it has an elongated shape and forms oligomers.
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Affiliation(s)
| | - Irini Topalidou
- Department of Biochemistry, University of Washington, Seattle, Washington
| | - Annie Dosey
- Department of Biochemistry, University of Washington, Seattle, Washington
| | - Alexey J Merz
- Department of Biochemistry, University of Washington, Seattle, Washington.,Department of Physiology and Biophysics, University of Washington, Seattle, Washington
| | - Michael Ailion
- Department of Biochemistry, University of Washington, Seattle, Washington
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41
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Giner A, Pascual L, Bourgeois M, Gyetvai G, Rios P, Picó B, Troadec C, Bendahmane A, Garcia-Mas J, Martín-Hernández AM. A mutation in the melon Vacuolar Protein Sorting 41prevents systemic infection of Cucumber mosaic virus. Sci Rep 2017; 7:10471. [PMID: 28874719 PMCID: PMC5585375 DOI: 10.1038/s41598-017-10783-3] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Accepted: 08/14/2017] [Indexed: 01/07/2023] Open
Abstract
In the melon exotic accession PI 161375, the gene cmv1, confers recessive resistance to Cucumber mosaic virus (CMV) strains of subgroup II. cmv1 prevents the systemic infection by restricting the virus to the bundle sheath cells and impeding viral loading to the phloem. Here we report the fine mapping and cloning of cmv1. Screening of an F2 population reduced the cmv1 region to a 132 Kb interval that includes a Vacuolar Protein Sorting 41 gene. CmVPS41 is conserved among plants, animals and yeast and is required for post-Golgi vesicle trafficking towards the vacuole. We have validated CmVPS41 as the gene responsible for the resistance, both by generating CMV susceptible transgenic melon plants, expressing the susceptible allele in the resistant cultivar and by characterizing CmVPS41 TILLING mutants with reduced susceptibility to CMV. Finally, a core collection of 52 melon accessions allowed us to identify a single amino acid substitution (L348R) as the only polymorphism associated with the resistant phenotype. CmVPS41 is the first natural recessive resistance gene found to be involved in viral transport and its cellular function suggests that CMV might use CmVPS41 for its own transport towards the phloem.
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Affiliation(s)
- Ana Giner
- Centre for Research in Agricultural Genomics (CRAG) CSIC-IRTA-UAB-UB, C/Vall Moronta, Edifici CRAG, Bellaterra (Cerdanyola del Vallés), 08193, Barcelona, Spain
| | - Laura Pascual
- Centre for Research in Agricultural Genomics (CRAG) CSIC-IRTA-UAB-UB, C/Vall Moronta, Edifici CRAG, Bellaterra (Cerdanyola del Vallés), 08193, Barcelona, Spain
- Unidad de Genética, Departamento de Biotecnología-Biología Vegetal, Escuela Técnica Superior de Ingenieros Agrónomos, Universidad Politécnica de Madrid, Madrid, Spain
| | - Michael Bourgeois
- Centre for Research in Agricultural Genomics (CRAG) CSIC-IRTA-UAB-UB, C/Vall Moronta, Edifici CRAG, Bellaterra (Cerdanyola del Vallés), 08193, Barcelona, Spain
| | - Gabor Gyetvai
- Centre for Research in Agricultural Genomics (CRAG) CSIC-IRTA-UAB-UB, C/Vall Moronta, Edifici CRAG, Bellaterra (Cerdanyola del Vallés), 08193, Barcelona, Spain
- KWS SAAT SE Grimsehlstr. 31, 37555, Einbeck, Germany
| | - Pablo Rios
- Centre for Research in Agricultural Genomics (CRAG) CSIC-IRTA-UAB-UB, C/Vall Moronta, Edifici CRAG, Bellaterra (Cerdanyola del Vallés), 08193, Barcelona, Spain
- Syngenta España S.A., C/Cartabona 10, 04710, El Ejido, Spain
| | - Belén Picó
- COMAV, Institute for the Conservation and Breeding of Agricultural Biodiversity, Universitat Politècnica de València (UPV), Camino de Vera s/n, 46022, Valencia, Spain
| | - Christelle Troadec
- INRA-CNRS, UMR1165, Unité de Recherche en Génomique Végétale, Evry, France
| | - Abdel Bendahmane
- INRA-CNRS, UMR1165, Unité de Recherche en Génomique Végétale, Evry, France
| | - Jordi Garcia-Mas
- Centre for Research in Agricultural Genomics (CRAG) CSIC-IRTA-UAB-UB, C/Vall Moronta, Edifici CRAG, Bellaterra (Cerdanyola del Vallés), 08193, Barcelona, Spain
- IRTA (Institut de Recerca i Tecnologia Agroalimentàries), Barcelona, Spain
| | - Ana Montserrat Martín-Hernández
- Centre for Research in Agricultural Genomics (CRAG) CSIC-IRTA-UAB-UB, C/Vall Moronta, Edifici CRAG, Bellaterra (Cerdanyola del Vallés), 08193, Barcelona, Spain.
- IRTA (Institut de Recerca i Tecnologia Agroalimentàries), Barcelona, Spain.
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42
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α-Synuclein promotes dilation of the exocytotic fusion pore. Nat Neurosci 2017; 20:681-689. [PMID: 28288128 PMCID: PMC5404982 DOI: 10.1038/nn.4529] [Citation(s) in RCA: 193] [Impact Index Per Article: 27.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Accepted: 02/05/2017] [Indexed: 01/08/2023]
Abstract
The protein α-synuclein has a central role in the pathogenesis of Parkinson’s disease (PD). Similar to other proteins that accumulate in neurodegenerative disease, however, the function of α-synuclein remains unknown. Localization to the nerve terminal suggests a role in neurotransmitter release and over-expression inhibits regulated exocytosis, but previous work has failed to identify a clear physiological defect in mice lacking all three synuclein isoforms. Using adrenal chromaffin cells and neurons, we now find that both over-expressed and endogenous synuclein serve to accelerate the kinetics of individual exocytotic events, promoting cargo discharge and reducing pore closure (‘kiss-and-run’). Thus, synuclein exerts dose-dependent effects on dilation of the exocytotic fusion pore. Remarkably, mutations that cause PD abrogate this property of α-synuclein without impairing its ability to inhibit exocytosis when over-expressed, indicating a selective defect in normal function.
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43
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Adaptor protein-3: A key player in RBL-2H3 mast cell mediator release. PLoS One 2017; 12:e0173462. [PMID: 28273137 PMCID: PMC5342237 DOI: 10.1371/journal.pone.0173462] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Accepted: 02/22/2017] [Indexed: 11/30/2022] Open
Abstract
Mast cell (MC) secretory granules are Lysosome-Related Organelles (LROs) whose biogenesis is associated with the post-Golgi secretory and endocytic pathways in which the sorting of proteins destined for a specific organelle relies on the recognition of sorting signals by adaptor proteins that direct their incorporation into transport vesicles. The adaptor protein 3 (AP-3) complex mediates protein trafficking between the trans-Golgi network (TGN) and late endosomes, lysosomes, and LROs. AP-3 has a recognized role in LROs biogenesis and regulated secretion in several cell types, including many immune cells such as neutrophils, natural killer cells, and cytotoxic T lymphocytes. However, the relevance of AP-3 for these processes in MCs has not been previously investigated. AP-3 was found to be expressed and distributed in a punctate fashion in rat peritoneal mast cells ex vivo. The rat MC line RBL-2H3 was used as a model system to investigate the role of AP-3 in mast cell secretory granule biogenesis and mediator release. By immunofluorescence and immunoelectron microscopy, AP-3 was localized both to the TGN and early endosomes indicating that AP-3 dependent sorting of proteins to MC secretory granules originates in these organelles. ShRNA mediated depletion of the AP-3 δ subunit was shown to destabilize the AP-3 complex in RBL-2H3 MCs. AP-3 knockdown significantly affected MC regulated secretion of β-hexosaminidase without affecting total cellular enzyme levels. Morphometric evaluation of MC secretory granules by electron microscopy revealed that the area of MC secretory granules in AP-3 knockdown MCs was significantly increased, indicating that AP-3 is involved in MC secretory granule biogenesis. Furthermore, AP-3 knockdown had a selective impact on the secretion of newly formed and newly synthesized mediators. These results show for the first time that AP-3 plays a critical role in secretory granule biogenesis and mediator release in MCs.
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Du W, Zhou M, Zhao W, Cheng D, Wang L, Lu J, Song E, Feng W, Xue Y, Xu P, Xu T. HID-1 is required for homotypic fusion of immature secretory granules during maturation. eLife 2016; 5. [PMID: 27751232 PMCID: PMC5094852 DOI: 10.7554/elife.18134] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Accepted: 10/17/2016] [Indexed: 02/06/2023] Open
Abstract
Secretory granules, also known as dense core vesicles, are generated at the trans-Golgi network and undergo several maturation steps, including homotypic fusion of immature secretory granules (ISGs) and processing of prehormones to yield active peptides. The molecular mechanisms governing secretory granule maturation are largely unknown. Here, we investigate a highly conserved protein named HID-1 in a mouse model. A conditional knockout of HID-1 in pancreatic β cells leads to glucose intolerance and a remarkable increase in the serum proinsulin/insulin ratio caused by defective proinsulin processing. Large volume three-dimensional electron microscopy and immunofluorescence imaging reveal that ISGs are much more abundant in the absence of HID-1. We further demonstrate that HID-1 deficiency prevented secretory granule maturation by blocking homotypic fusion of immature secretory granules. Our data identify a novel player during the early maturation of immature secretory granules.
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Affiliation(s)
- Wen Du
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Maoge Zhou
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Wei Zhao
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Dongwan Cheng
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Lifen Wang
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Jingze Lu
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Eli Song
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Wei Feng
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Yanhong Xue
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Pingyong Xu
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China.,Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Tao Xu
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
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45
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Ho R, Stroupe C. The HOPS/Class C Vps Complex Tethers High-Curvature Membranes via a Direct Protein-Membrane Interaction. Traffic 2016; 17:1078-90. [PMID: 27307091 DOI: 10.1111/tra.12421] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Revised: 06/13/2016] [Accepted: 06/13/2016] [Indexed: 01/13/2023]
Abstract
Membrane tethering is a physical association of two membranes before their fusion. Many membrane tethering factors have been identified, but the interactions that mediate inter-membrane associations remain largely a matter of conjecture. Previously, we reported that the homotypic fusion and protein sorting/Class C vacuolar protein sorting (HOPS/Class C Vps) complex, which has two binding sites for the yeast vacuolar Rab GTPase Ypt7p, can tether two low-curvature liposomes when both membranes bear Ypt7p. Here, we show that HOPS tethers highly curved liposomes to Ypt7p-bearing low-curvature liposomes even when the high-curvature liposomes are protein-free. Phosphorylation of the curvature-sensing amphipathic lipid-packing sensor (ALPS) motif from the Vps41p HOPS subunit abrogates tethering of high-curvature liposomes. A HOPS complex without its Vps39p subunit, which contains one of the Ypt7p binding sites in HOPS, lacks tethering activity, though it binds high-curvature liposomes and Ypt7p-bearing low-curvature liposomes. Thus, HOPS tethers highly curved membranes via a direct protein-membrane interaction. Such high-curvature membranes are found at the sites of vacuole tethering and fusion. There, vacuole membranes bend sharply, generating large areas of vacuole-vacuole contact. We propose that HOPS localizes via the Vps41p ALPS motif to these high-curvature regions. There, HOPS binds via Vps39p to Ypt7p in an apposed vacuole membrane.
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Affiliation(s)
- Ruoya Ho
- Department of Molecular Physiology and Biological Physics and Center for Membrane Biology, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - Christopher Stroupe
- Department of Molecular Physiology and Biological Physics and Center for Membrane Biology, University of Virginia School of Medicine, Charlottesville, VA, USA.
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46
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Mizutani A, Inoko H, Tanaka M. Carboxypeptidase E, Identified As a Direct Interactor of Growth Hormone, Is Important for Efficient Secretion of the Hormone. Mol Cells 2016; 39:756-761. [PMID: 27788574 PMCID: PMC5104884 DOI: 10.14348/molcells.2016.0183] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Revised: 09/09/2016] [Accepted: 09/22/2016] [Indexed: 11/27/2022] Open
Abstract
We have identified 88 interactor candidates for human growth hormone (GH) by the yeast two-hybrid assay. Among those, we focused our efforts on carboxypeptidase E (CPE), which has been thought to play a key role in sorting prohormones, such as pro-opiomelanocortin (POMC), to regulated secretory vesicles. We found that CPE co-localizes with and interacts with GH in AtT20 pituitary cells. Downregulation of CPE led to decreased levels of GH secretion, consistent with involvement of CPE in GH sorting/secretion. Our binding assay in vitro with bacterially expressed proteins suggested that GH directly interacts with CPE but in a manner different from POMC.
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Affiliation(s)
- Akiko Mizutani
- Basic Medical Science and Molecular Medicine, Tokai University School of Medicine, Isehara, Kanagawa 259-1193,
Japan
- Faculty of Health and Medical Science, Teikyo Heisei University, Higashi-Ikebukuro, Toshima, Tokyo 170-8445,
Japan
| | - Hidetoshi Inoko
- Basic Medical Science and Molecular Medicine, Tokai University School of Medicine, Isehara, Kanagawa 259-1193,
Japan
| | - Masafumi Tanaka
- Basic Medical Science and Molecular Medicine, Tokai University School of Medicine, Isehara, Kanagawa 259-1193,
Japan
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47
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Hurwitz SN, Conlon MM, Rider MA, Brownstein NC, Meckes DG. Nanoparticle analysis sheds budding insights into genetic drivers of extracellular vesicle biogenesis. J Extracell Vesicles 2016; 5:31295. [PMID: 27421995 PMCID: PMC4947197 DOI: 10.3402/jev.v5.31295] [Citation(s) in RCA: 115] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Revised: 06/02/2016] [Accepted: 06/07/2016] [Indexed: 01/22/2023] Open
Abstract
Background Extracellular vesicles (EVs) are important mediators of cell-to-cell communication in healthy and pathological environments. Because EVs are present in a variety of biological fluids and contain molecular signatures of their cell or tissue of origin, they have great diagnostic and prognostic value. The ability of EVs to deliver biologically active proteins, RNAs and lipids to cells has generated interest in developing novel therapeutics. Despite their potential medical use, many of the mechanisms underlying EV biogenesis and secretion remain unknown. Methods Here, we characterized vesicle secretion across the NCI-60 panel of human cancer cells by nanoparticle tracking analysis. Using CellMiner, the quantity of EVs secreted by each cell line was compared to reference transcriptomics data to identify gene products associated with vesicle secretion. Results Gene products positively associated with the quantity of exosomal-sized vesicles included vesicular trafficking classes of proteins with Rab GTPase function and sphingolipid metabolism. Positive correlates of larger microvesicle-sized vesicle secretion included gene products involved in cytoskeletal dynamics and exocytosis, as well as Rab GTPase activation. One of the identified targets, CD63, was further evaluated for its role in vesicle secretion. Clustered regularly interspaced short palindromic repeat (CRISPR)/Cas9 knockout of the CD63 gene in HEK293 cells resulted in a decrease in small vesicle secretion, suggesting the importance of CD63 in exosome biogenesis. Conclusion These observations reveal new insights into genes involved in exosome and microvesicle formation, and may provide a means to distinguish EV sub-populations. This study offers a foundation for further exploration of targets involved in EV biogenesis and secretion.
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Affiliation(s)
- Stephanie N Hurwitz
- Department of Biomedical Sciences, Florida State University College of Medicine, Tallahassee, FL, USA
| | - Meghan M Conlon
- Department of Biomedical Sciences, Florida State University College of Medicine, Tallahassee, FL, USA
| | - Mark A Rider
- Department of Biomedical Sciences, Florida State University College of Medicine, Tallahassee, FL, USA
| | - Naomi C Brownstein
- Department of Behavioral Sciences and Social Medicine, Florida State University College of Medicine, Tallahassee, FL, USA
| | - David G Meckes
- Department of Biomedical Sciences, Florida State University College of Medicine, Tallahassee, FL, USA;
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48
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Topalidou I, Cattin-Ortolá J, Pappas AL, Cooper K, Merrihew GE, MacCoss MJ, Ailion M. The EARP Complex and Its Interactor EIPR-1 Are Required for Cargo Sorting to Dense-Core Vesicles. PLoS Genet 2016; 12:e1006074. [PMID: 27191843 PMCID: PMC4871572 DOI: 10.1371/journal.pgen.1006074] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Accepted: 04/30/2016] [Indexed: 12/15/2022] Open
Abstract
The dense-core vesicle is a secretory organelle that mediates the regulated release of peptide hormones, growth factors, and biogenic amines. Dense-core vesicles originate from the trans-Golgi of neurons and neuroendocrine cells, but it is unclear how this specialized organelle is formed and acquires its specific cargos. To identify proteins that act in dense-core vesicle biogenesis, we performed a forward genetic screen in Caenorhabditis elegans for mutants defective in dense-core vesicle function. We previously reported the identification of two conserved proteins that interact with the small GTPase RAB-2 to control normal dense-core vesicle cargo-sorting. Here we identify several additional conserved factors important for dense-core vesicle cargo sorting: the WD40 domain protein EIPR-1 and the endosome-associated recycling protein (EARP) complex. By assaying behavior and the trafficking of dense-core vesicle cargos, we show that mutants that lack EIPR-1 or EARP have defects in dense-core vesicle cargo-sorting similar to those of mutants in the RAB-2 pathway. Genetic epistasis data indicate that RAB-2, EIPR-1 and EARP function in a common pathway. In addition, using a proteomic approach in rat insulinoma cells, we show that EIPR-1 physically interacts with the EARP complex. Our data suggest that EIPR-1 is a new interactor of the EARP complex and that dense-core vesicle cargo sorting depends on the EARP-dependent trafficking of cargo through an endosomal sorting compartment. Animal cells package and store many important signaling molecules in specialized compartments called dense-core vesicles. Molecules stored in dense-core vesicles include peptide hormones like insulin and small molecule neurotransmitters like dopamine. Defects in the release of these compounds can lead to a wide range of metabolic and mental disorders in humans, including diabetes, depression, and drug addiction. However, it is not well understood how dense-core vesicles are formed in cells and package the appropriate molecules. Here we use a genetic screen in the microscopic worm C. elegans to identify proteins that are important for early steps in the generation of dense-core vesicles, such as packaging the correct molecular cargos in the vesicles. We identify several factors that are conserved between worms and humans and point to a new role for a protein complex that had previously been shown to be important for controlling trafficking in other cellular compartments. The identification of this complex suggests new cellular trafficking events that may be important for the generation of dense-core vesicles.
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Affiliation(s)
- Irini Topalidou
- Department of Biochemistry, University of Washington, Seattle, Washington, United States of America
| | - Jérôme Cattin-Ortolá
- Department of Biochemistry, University of Washington, Seattle, Washington, United States of America
| | - Andrea L. Pappas
- Department of Neurobiology, Duke University School of Medicine, Durham, North Carolina, United States of America
| | - Kirsten Cooper
- Department of Biochemistry, University of Washington, Seattle, Washington, United States of America
| | - Gennifer E. Merrihew
- Department of Genome Sciences, University of Washington, Seattle, Washington, United States of America
| | - Michael J. MacCoss
- Department of Genome Sciences, University of Washington, Seattle, Washington, United States of America
| | - Michael Ailion
- Department of Biochemistry, University of Washington, Seattle, Washington, United States of America
- * E-mail:
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49
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AtVPS41-mediated endocytic pathway is essential for pollen tube-stigma interaction in Arabidopsis. Proc Natl Acad Sci U S A 2016; 113:6307-12. [PMID: 27185920 DOI: 10.1073/pnas.1602757113] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In flowering plants, extensive male-female interactions are required for successful fertilization in which various signaling cascades are involved. Prevacuolar compartments (PVC) and vacuoles are two types of subcellular compartments that terminate signal transduction by sequestrating signaling molecules in yeast and mammalian cells; however, the manner in which they might be involved in male-female interactions in plants is unknown. In this study, we identified Arabidopsis thaliana vacuolar protein sorting 41 (AtVPS41), encoded by a single-copy gene with sequence similarity to yeast Vps41p, as a new factor controlling pollen tube-stigma interaction. Loss of AtVPS41 function disrupted penetration of pollen tubes into the transmitting tissue and thus led to failed male transmission. In the pollen tubes, AtVPS41 protein is associated with PVCs and the tonoplast. We demonstrate that AtVPS41 is required for the late stage of the endocytic pathway (i.e., endomembrane trafficking from PVCs to vacuoles) because internalization of cell-surface molecules was normal in the vps41-deficient pollen tubes, whereas PVC-to-vacuole trafficking was impaired. We further show that the CHCR domain is required for subcellular localization and biological functioning of AtVPS41. These results indicate that the AtVPS41-mediated late stage of the endocytic pathway is essential for pollen tube-stigma interaction in Arabidopsis.
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50
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Spang A. Membrane Tethering Complexes in the Endosomal System. Front Cell Dev Biol 2016; 4:35. [PMID: 27243003 PMCID: PMC4860415 DOI: 10.3389/fcell.2016.00035] [Citation(s) in RCA: 81] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Accepted: 04/18/2016] [Indexed: 01/08/2023] Open
Abstract
Vesicles that are generated by endocytic events at the plasma membrane are destined to early endosomes. A prerequisite for proper fusion is the tethering of two membrane entities. Tethering of vesicles to early endosomes is mediated by the class C core vacuole/endosome tethering (CORVET) complex, while fusion of late endosomes with lysosomes depends on the homotypic fusion and vacuole protein sorting (HOPS) complex. Recycling through the trans-Golgi network (TGN) and to the plasma membrane is facilitated by the Golgi associated retrograde protein (GARP) and endosome-associated recycling protein (EARP) complexes, respectively. However, there are other tethering functions in the endosomal system as there are multiple pathways through which proteins can be delivered from endosomes to either the TGN or the plasma membrane. Furthermore, proteins that may be part of novel tethering complexes have been recently identified. Thus, it is likely that more tethering factors exist. In this review, I will provide an overview of different tethering complexes of the endosomal system and discuss how they may provide specificity in membrane traffic.
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Affiliation(s)
- Anne Spang
- Biozentrum, Growth & Development, University of Basel Basel, Switzerland
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