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Chen LL, Huang YJ, Cui JT, Song N, Xie J. Iron Dysregulation in Parkinson's Disease: Focused on the Autophagy-Lysosome Pathway. ACS Chem Neurosci 2019; 10:863-871. [PMID: 30590010 DOI: 10.1021/acschemneuro.8b00390] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Parkinson's disease (PD) is the second most common neurodegenerative disease and is characterized by dopaminergic neuron loss in the substantia nigra pars compacta (SNpc). Although both iron accumulation and a defective autophagy-lysosome pathway contribute to the pathological development of PD, the connection between these two causes is poorly documented. The autophagy-lysosome pathway not only responds to regulation by iron chelators and channels but also participates in cellular iron recycling through the degradation of ferritin and other iron-containing components. Previously, ferritin has been posited to be the bridge between iron accumulation and autophagy impairment in PD. In addition, iron directly interacts with α-synuclein in Lewy bodies, which are primarily digested through the autophagy-lysosome pathway. These findings indicate that some link exists between iron deposition and autophagy impairment in PD. In this review, the basic mechanisms of the autophagy-lysosome pathway and iron trafficking are introduced, and then their interaction under physiological conditions is explained. Finally, we finish by discussing the dysfunction of iron deposition and autophagy in PD, as well as their potential relationship, which will provide some insight for further study.
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Affiliation(s)
- Lei-Lei Chen
- Institute of Brain Science and Disease, Shandong Provincial Collaborative Innovation Center for Neurodegenerative Disorders, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders, Qingdao University, Qingdao, Shandong 266071, China
| | - Yu-Jv Huang
- Institute of Brain Science and Disease, Shandong Provincial Collaborative Innovation Center for Neurodegenerative Disorders, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders, Qingdao University, Qingdao, Shandong 266071, China
| | - Jun-tao Cui
- Institute of Brain Science and Disease, Shandong Provincial Collaborative Innovation Center for Neurodegenerative Disorders, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders, Qingdao University, Qingdao, Shandong 266071, China
| | - Ning Song
- Institute of Brain Science and Disease, Shandong Provincial Collaborative Innovation Center for Neurodegenerative Disorders, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders, Qingdao University, Qingdao, Shandong 266071, China
| | - Junxia Xie
- Institute of Brain Science and Disease, Shandong Provincial Collaborative Innovation Center for Neurodegenerative Disorders, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders, Qingdao University, Qingdao, Shandong 266071, China
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Rab5-independent activation and function of yeast Rab7-like protein, Ypt7p, in the AP-3 pathway. PLoS One 2019; 14:e0210223. [PMID: 30682048 PMCID: PMC6347229 DOI: 10.1371/journal.pone.0210223] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Accepted: 12/18/2018] [Indexed: 11/19/2022] Open
Abstract
The small GTPases, Rab5 and Rab7, are key regulators at multiple stages of the endocytic/endolysosomal pathway, including fusion and maturation of endosomes. In yeast, Vps21p (Rab5 homolog) recruits a GEF for Rab7 and activates the downstream Ypt7p (Rab7 homolog) on endosomal membrane. Although the model of this sequential activation from Vps21p to Ypt7p in the endocytic pathway has been established, activation mechanism of Ypt7p in the Vps21p-independent pathway has not been completely clarified. Here we show that Ypt7p is activated and mediates vacuolar fusion in cells lacking all yeast Rab5 genes, VPS21, YPT52, and YPT53. We also demonstrate that deletion of both VPS21 and YPT7 genes cause severe defect in the AP-3 pathway as well as the CPY pathway although the AP-3 pathway is mostly intact in each vps21Δ or ypt7Δ mutant. Interestingly, in vps21Δ ypt7Δ mutant cargos trafficked via the VPS or endocytic pathway accumulate beside nucleus whereas cargo trafficked via the AP-3 pathway disperse in the cytosol. These findings suggest that Ypt7p is activated and plays a Rab5-independent role in the AP-3-mediated pathway.
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53
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Stroupe C. This Is the End: Regulation of Rab7 Nucleotide Binding in Endolysosomal Trafficking and Autophagy. Front Cell Dev Biol 2018; 6:129. [PMID: 30333976 PMCID: PMC6176412 DOI: 10.3389/fcell.2018.00129] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Accepted: 09/14/2018] [Indexed: 01/07/2023] Open
Abstract
Rab7 – or in yeast, Ypt7p – governs membrane trafficking in the late endocytic and autophagic pathways. Rab7 also regulates mitochondrion-lysosome contacts, the sites of mitochondrial fission. Like all Rab GTPases, Rab7 cycles between an “active” GTP-bound form that binds downstream effectors – e.g., the HOPS and retromer complexes and the dynactin-binding Rab-interacting lysosomal protein (RILP) – and an “inactive” GDP-bound form that cannot bind effectors. Accessory proteins regulate the nucleotide binding state of Rab7: guanine nucleotide exchange factors (GEFs) stimulate exchange of bound GDP for GTP, resulting in Rab7 activation, whereas GTPase activating proteins (GAPs) boost Rab7’s GTP hydrolysis activity, thereby inactivating Rab7. This review will discuss the GEF and GAPs that control Rab7 nucleotide binding, and thus regulate Rab7’s activity in endolysosomal trafficking and autophagy. It will also consider how bacterial pathogens manipulate Rab7 nucleotide binding to support intracellular invasion and immune evasion.
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Affiliation(s)
- Christopher Stroupe
- Department of Molecular Physiology and Biological Physics, University of Virginia School of Medicine, Charlottesville, VA, United States
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54
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Carpinone EM, Li Z, Mills MK, Foltz C, Brannon ER, Carlow CKS, Starai VJ. Identification of putative effectors of the Type IV secretion system from the Wolbachia endosymbiont of Brugia malayi. PLoS One 2018; 13:e0204736. [PMID: 30261054 PMCID: PMC6160203 DOI: 10.1371/journal.pone.0204736] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Accepted: 09/13/2018] [Indexed: 11/19/2022] Open
Abstract
Wolbachia is an unculturable, intracellular bacterium that persists within an extremely broad range of arthropod and parasitic nematode hosts, where it is transmitted maternally to offspring via vertical transmission. In the filarial nematode Brugia malayi, a causative agent of human lymphatic filariasis, Wolbachia is an endosymbiont, and its presence is essential for proper nematode development, survival, and pathogenesis. While the elucidation of Wolbachia:nematode interactions that promote the bacterium’s intracellular persistence is of great importance, research has been hampered due to the fact that Wolbachia cannot be cultured in the absence of host cells. The Wolbachia endosymbiont of B. malayi (wBm) has an active Type IV secretion system (T4SS). Here, we have screened 47 putative T4SS effector proteins of wBm for their ability to modulate growth or the cell biology of a typical eukaryotic cell, Saccharomyces cerevisiae. Five candidates strongly inhibited yeast growth upon expression, and 6 additional proteins showed toxicity in the presence of zinc and caffeine. Studies on the uptake of an endocytic vacuole-specific fluorescent marker, FM4-64, identified 4 proteins (wBm0076 wBm00114, wBm0447 and wBm0152) involved in vacuole membrane dynamics. The WAS(p)-family protein, wBm0076, was found to colocalize with yeast cortical actin patches and disrupted actin cytoskeleton dynamics upon expression. Deletion of the Arp2/3-activating protein, Abp1p, provided resistance to wBm0076 expression, suggesting a role for wBm0076 in regulating eukaryotic actin dynamics and cortical actin patch formation. Furthermore, wBm0152 was found to strongly disrupt endosome:vacuole cargo trafficking in yeast. This study provides molecular insight into the potential role of the T4SS in the Wolbachia endosymbiont:nematode relationship.
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Affiliation(s)
- Emily M. Carpinone
- Department of Microbiology, University of Georgia, Athens, GA, United States of America
| | - Zhiru Li
- Division of Genome Biology, New England Biolabs, Ipswich, MA, United States of America
| | - Michael K. Mills
- Department of Microbiology, University of Georgia, Athens, GA, United States of America
| | - Clemence Foltz
- Division of Genome Biology, New England Biolabs, Ipswich, MA, United States of America
| | - Emma R. Brannon
- Department of Microbiology, University of Georgia, Athens, GA, United States of America
| | - Clotilde K. S. Carlow
- Division of Genome Biology, New England Biolabs, Ipswich, MA, United States of America
| | - Vincent J. Starai
- Department of Microbiology, University of Georgia, Athens, GA, United States of America
- Department of Infectious Diseases, University of Georgia, Athens, GA, United States of America
- * E-mail:
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55
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Gao J, Reggiori F, Ungermann C. A novel in vitro assay reveals SNARE topology and the role of Ykt6 in autophagosome fusion with vacuoles. J Cell Biol 2018; 217:3670-3682. [PMID: 30097515 PMCID: PMC6168247 DOI: 10.1083/jcb.201804039] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Revised: 06/13/2018] [Accepted: 07/06/2018] [Indexed: 11/22/2022] Open
Abstract
Autophagosome fusion with vacuoles requires a conserved fusion machinery, though the topology remained unclear. Two papers in this issue, Bas et al. and Gao et al., uncover Ykt6 as the required autophagosomal SNARE. Autophagy is a catabolic pathway that delivers intracellular material to the mammalian lysosomes or the yeast and plant vacuoles. The final step in this process is the fusion of autophagosomes with vacuoles, which requires SNARE proteins, the homotypic vacuole fusion and protein sorting tethering complex, the RAB7-like Ypt7 GTPase, and its guanine nucleotide exchange factor, Mon1-Ccz1. Where these different components are located and function during fusion, however, remains to be fully understood. Here, we present a novel in vitro assay to monitor fusion of intact and functional autophagosomes with vacuoles. This process requires ATP, physiological temperature, and the entire fusion machinery to tether and fuse autophagosomes with vacuoles. Importantly, we uncover Ykt6 as the autophagosomal SNARE. Our assay and findings thus provide the tools to dissect autophagosome completion and fusion in a test tube.
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Affiliation(s)
- Jieqiong Gao
- Biochemistry Section, Department of Biology/Chemistry, University of Osnabrück, Osnabrück, Germany
| | - Fulvio Reggiori
- Department of Cell Biology, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
| | - Christian Ungermann
- Biochemistry Section, Department of Biology/Chemistry, University of Osnabrück, Osnabrück, Germany .,Center of Cellular Nanoanalytics Osnabrück (CellNanOs), University of Osnabrück, Osnabrück, Germany
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56
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Langemeyer L, Fröhlich F, Ungermann C. Rab GTPase Function in Endosome and Lysosome Biogenesis. Trends Cell Biol 2018; 28:957-970. [PMID: 30025982 DOI: 10.1016/j.tcb.2018.06.007] [Citation(s) in RCA: 244] [Impact Index Per Article: 40.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 06/15/2018] [Accepted: 06/25/2018] [Indexed: 10/28/2022]
Abstract
Eukaryotic cells maintain a highly organized endolysosomal system. This system regulates the protein and lipid content of the plasma membrane, it participates in the intracellular quality control machinery and is needed for the efficient removal of damaged organelles. This complex network comprises an endosomal membrane system that feeds into the lysosomes, yet also allows recycling of membrane proteins, and probably lipids. Moreover, lysosomal degradation provides the cell with macromolecules for further growth. In this review, we focus primarily on the role of the small Rab GTPases Rab5 and Rab7 as organelle markers and interactors of multiple effectors on endosomes and lysosomes and highlight their role in membrane dynamics, particularly fusion along the endolysosomal pathway.
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Affiliation(s)
- Lars Langemeyer
- Department of Biology/Chemistry, Biochemistry Section, University of Osnabrück, Barbarastrasse 13, 49076 Osnabrück, Germany
| | - Florian Fröhlich
- Department of Biology/Chemistry, Molecular Membrane Biology Group, University of Osnabrück, Barbarastrasse 13, 49076 Osnabrück, Germany; Center of Cellular Nanoanalytics of the University of Osnabrück (CellNanOs), Barbarastrasse 11, 49076 Osnabrück, Germany
| | - Christian Ungermann
- Department of Biology/Chemistry, Biochemistry Section, University of Osnabrück, Barbarastrasse 13, 49076 Osnabrück, Germany; Department of Biology/Chemistry, Molecular Membrane Biology Group, University of Osnabrück, Barbarastrasse 13, 49076 Osnabrück, Germany; Center of Cellular Nanoanalytics of the University of Osnabrück (CellNanOs), Barbarastrasse 11, 49076 Osnabrück, Germany.
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57
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Yu L, Chen Y, Tooze SA. Autophagy pathway: Cellular and molecular mechanisms. Autophagy 2017; 14:207-215. [PMID: 28933638 PMCID: PMC5902171 DOI: 10.1080/15548627.2017.1378838] [Citation(s) in RCA: 942] [Impact Index Per Article: 134.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Revised: 08/04/2017] [Accepted: 09/07/2017] [Indexed: 02/06/2023] Open
Abstract
Macroautophagy/autophagy is an essential, conserved self-eating process that cells perform to allow degradation of intracellular components, including soluble proteins, aggregated proteins, organelles, macromolecular complexes, and foreign bodies. The process requires formation of a double-membrane structure containing the sequestered cytoplasmic material, the autophagosome, that ultimately fuses with the lysosome. This review will define this process and the cellular pathways required, from the formation of the double membrane to the fusion with lysosomes in molecular terms, and in particular highlight the recent progress in our understanding of this complex process.
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Affiliation(s)
- Li Yu
- State Key Laboratory of Membrane Biology, Tsinghua University-Peking University Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Yang Chen
- State Key Laboratory of Membrane Biology, Tsinghua University-Peking University Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Sharon A. Tooze
- Molecular Cell Biology of Autophagy, The Francis Crick Institute, London, United Kingdom
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58
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Abstract
Macroautophagy is an intracellular pathway used for targeting of cellular components to the lysosome for their degradation and involves sequestration of cytoplasmic material into autophagosomes formed from a double membrane structure called the phagophore. The nucleation and elongation of the phagophore is tightly regulated by several autophagy-related (ATG) proteins, but also involves vesicular trafficking from different subcellular compartments to the forming autophagosome. Such trafficking must be tightly regulated by various intra- and extracellular signals to respond to different cellular stressors and metabolic states, as well as the nature of the cargo to become degraded. We are only starting to understand the interconnections between different membrane trafficking pathways and macroautophagy. This review will focus on the membrane trafficking machinery found to be involved in delivery of membrane, lipids, and proteins to the forming autophagosome and in the subsequent autophagosome fusion with endolysosomal membranes. The role of RAB proteins and their regulators, as well as coat proteins, vesicle tethers, and SNARE proteins in autophagosome biogenesis and maturation will be discussed.
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59
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Zheng JX, Li Y, Ding YH, Liu JJ, Zhang MJ, Dong MQ, Wang HW, Yu L. Architecture of the ATG2B-WDR45 complex and an aromatic Y/HF motif crucial for complex formation. Autophagy 2017; 13:1870-1883. [PMID: 28820312 DOI: 10.1080/15548627.2017.1359381] [Citation(s) in RCA: 81] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
Abstract
PtdIns3P signaling is critical for dynamic membrane remodeling during autophagosome formation. Proteins in the Atg18/WIPI family are PtdIns3P-binding effectors which can form complexes with proteins in the Atg2 family, and both families are essential for macroautophagy/autophagy. However, little is known about the biophysical properties and biological functions of the Atg2-Atg18/WIPI complex as a whole. Here, we demonstrate that an ortholog of yeast Atg18, mammalian WDR45/WIPI4 has a stronger binding capacity for mammalian ATG2A or ATG2B than the other 3 WIPIs. We purified the full-length Rattus norvegicus ATG2B and found that it could bind to liposomes independently of PtdIns3P or WDR45. We also purified the ATG2B-WDR45 complex and then performed 3-dimensional reconstruction of the complex by single-particle electron microscopy, which revealed a club-shaped heterodimer with an approximate length of 22 nm. Furthermore, we performed cross-linking mass spectrometry and identified a set of highly cross-linked intermolecular and intramolecular lysine pairs. Finally, based on the cross-linking data followed by bioinformatics and mutagenesis analysis, we determined the conserved aromatic H/YF motif in the C terminus of ATG2A and ATG2B that is crucial for complex formation.
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Affiliation(s)
- Jing-Xiang Zheng
- a State Key Laboratory of Membrane Biology , Tsinghua University-Peking University Joint Center for Life Sciences, School of Life Sciences, Tsinghua University , Beijing , China.,b Joint Graduate Program of Peking-Tsinghua-National Institute of Biological Science , Tsinghua University , Beijing , China
| | - Yan Li
- c Ministry of Education Key Laboratory of Protein Sciences , Tsinghua-Peking Joint Center for Life Sciences , Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing , China
| | - Yue-He Ding
- d National Institute of Biological Sciences , Beijing , China
| | - Jun-Jie Liu
- b Joint Graduate Program of Peking-Tsinghua-National Institute of Biological Science , Tsinghua University , Beijing , China.,c Ministry of Education Key Laboratory of Protein Sciences , Tsinghua-Peking Joint Center for Life Sciences , Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing , China
| | - Mei-Jun Zhang
- d National Institute of Biological Sciences , Beijing , China
| | - Meng-Qiu Dong
- d National Institute of Biological Sciences , Beijing , China
| | - Hong-Wei Wang
- c Ministry of Education Key Laboratory of Protein Sciences , Tsinghua-Peking Joint Center for Life Sciences , Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing , China
| | - Li Yu
- a State Key Laboratory of Membrane Biology , Tsinghua University-Peking University Joint Center for Life Sciences, School of Life Sciences, Tsinghua University , Beijing , China
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Yuan S, Zhang ZW, Li ZL. Trehalose May Decrease the Transmission of Zika Virus to the Fetus by Activating Degradative Autophagy. Front Cell Infect Microbiol 2017; 7:402. [PMID: 28932709 PMCID: PMC5592200 DOI: 10.3389/fcimb.2017.00402] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Accepted: 08/25/2017] [Indexed: 01/14/2023] Open
Affiliation(s)
- Shu Yuan
- College of Resources, Sichuan Agricultural UniversityChengdu, China
| | - Zhong-Wei Zhang
- College of Resources, Sichuan Agricultural UniversityChengdu, China
| | - Zi-Lin Li
- Department of Cardiovascular Surgery, Xijing Hospital, Medical University of the Air ForceXi'an, China
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61
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Zhan L, Chen S, Li K, Liang D, Zhu X, Liu L, Lu Z, Sun W, Xu E. Autophagosome maturation mediated by Rab7 contributes to neuroprotection of hypoxic preconditioning against global cerebral ischemia in rats. Cell Death Dis 2017; 8:e2949. [PMID: 28726776 PMCID: PMC5550874 DOI: 10.1038/cddis.2017.330] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Revised: 05/21/2017] [Accepted: 06/05/2017] [Indexed: 12/18/2022]
Abstract
Autophagy disruption leads to neuronal damage in hypoxic–ischemic brain injury. Rab7, a member of the Rab GTPase superfamily, has a unique role in the regulation of autophagy. Hypoxic preconditioning (HPC) provides neuroprotection against transient global cerebral ischemia (tGCI). However, the underlying mechanisms remain poorly understood. Thus, the current study explored the potential molecular mechanism of the neuroprotective effect of HPC by investigating how Rab7 mediates autophagosome (AP) maturation after tGCI in adult rats. We found that HPC attenuated AP accumulation in the hippocampal CA1 region after tGCI via restoration of autophagic flux. We also confirmed that this HPC-induced neuroprotection was not caused by the increase in lysosomes or the improvement of lysosomal function after tGCI. Electron microscopic analysis then revealed an increase in autolysosomes in CA1 neurons of HPC rats. Moreover, the inhibition of autophagosome-lysosome fusion by chloroquine significantly aggravated neuronal death in CA1, indicating that AP maturation contributes to HPC-induced neuroprotection against neuronal injury after tGCI. Furthermore, the activation of Rab7 was found to be involved in the neuroprotective effect of AP maturation after HPC. At last, the knockdown of ultraviolet radiation resistance-associated gene (UVRAG) in vivo disrupted the interaction between Vps16 and Rab7, attenuated the activation of Rab7, interrupted autophagic flux, and ultimately abrogated the HPC-induced neuroprotection against tGCI. Our results indicated that AP maturation was enhanced by the activation of Rab7 via UVRAG-Vps16 interaction, which further demonstrated the potential neuroprotective role of Rab7 in HPC against tGCI-induced neuronal injury in adult rats.
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Affiliation(s)
- Lixuan Zhan
- Institute of Neurosciences and Department of Neurology of The Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and The Ministry of Education of China, Guangzhou 510260, China
| | - Siyuan Chen
- Institute of Neurosciences and Department of Neurology of The Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and The Ministry of Education of China, Guangzhou 510260, China
| | - Kongping Li
- Institute of Neurosciences and Department of Neurology of The Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and The Ministry of Education of China, Guangzhou 510260, China
| | - Donghai Liang
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta 30322, Georgia
| | - Xinyong Zhu
- Institute of Neurosciences and Department of Neurology of The Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and The Ministry of Education of China, Guangzhou 510260, China
| | - Liu Liu
- Institute of Neurosciences and Department of Neurology of The Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and The Ministry of Education of China, Guangzhou 510260, China
| | - Zhiwei Lu
- Institute of Neurosciences and Department of Neurology of The Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and The Ministry of Education of China, Guangzhou 510260, China
| | - Weiwen Sun
- Institute of Neurosciences and Department of Neurology of The Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and The Ministry of Education of China, Guangzhou 510260, China
| | - En Xu
- Institute of Neurosciences and Department of Neurology of The Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and The Ministry of Education of China, Guangzhou 510260, China
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Li B, Liu L, Li Y, Dong X, Zhang H, Chen H, Zheng X, Zhang Z. The FgVps39-FgVam7-FgSso1 Complex Mediates Vesicle Trafficking and Is Important for the Development and Virulence of Fusarium graminearum. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2017; 30:410-422. [PMID: 28437167 DOI: 10.1094/mpmi-11-16-0242-r] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Vesicle trafficking is an important event in eukaryotic organisms. Many proteins and lipids transported between different organelles or compartments are essential for survival. These processes are mediated by soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins, Rab-GTPases, and multisubunit tethering complexes such as class C core vacuole or endosome tethering and homotypic fusion or vacuole protein sorting (HOPS). Our previous study has demonstrated that FgVam7, which encodes a SNARE protein involving in vesicle trafficking, plays crucial roles in growth, asexual or sexual development, deoxynivalenol production, and pathogenicity in Fusarium graminearum. Here, the affinity purification approach was used to identify FgVam7-interacting proteins to explore its regulatory mechanisms during vesicle trafficking. The orthologs of yeast Vps39, a HOPS tethering complex subunit, and Sso1, a SNARE protein localized to the vacuole or endosome, were identified and selected for further characterization. In yeast two-hybrid and glutathione-S-transferase pull-down assays, FgVam7, FgVps39, and FgSso1 interacted with each other as a complex. The ∆Fgvps39 mutant generated by targeted deletion was significantly reduced in vegetative growth and asexual development. It failed to produce sexual spores and was defective in plant infection and deoxynivalenol production. Further cellular localization and cytological examinations suggested that FgVps39 is involved in vesicle trafficking from early or late endosomes to vacuoles in F. graminearum. Additionally, the ∆Fgvps39 mutant was defective in vacuole morphology and autophagy, and it was delayed in endocytosis. Our results demonstrate that FgVam7 interacts with FgVps39 and FgSso1 to form a unique complex, which is involved in vesicle trafficking and modulating the proper development of infection-related morphogenesis in F. graminearum.
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Affiliation(s)
- Bing Li
- 1 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; and
| | - Luping Liu
- 1 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; and
| | - Ying Li
- 1 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; and
| | - Xin Dong
- 1 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; and
| | - Haifeng Zhang
- 1 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; and
| | - Huaigu Chen
- 2 Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
| | - Xiaobo Zheng
- 1 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; and
| | - Zhengguang Zhang
- 1 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; and
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Cheng X, Ma X, Ding X, Li L, Jiang X, Shen Z, Chen S, Liu W, Gong W, Sun Q. Pacer Mediates the Function of Class III PI3K and HOPS Complexes in Autophagosome Maturation by Engaging Stx17. Mol Cell 2017; 65:1029-1043.e5. [DOI: 10.1016/j.molcel.2017.02.010] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Revised: 01/06/2017] [Accepted: 02/10/2017] [Indexed: 11/25/2022]
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64
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Chinchwadkar S, Padmanabhan S, Mishra P, Singh S, Suresh SN, Vats S, Barve G, Ammanathan V, Manjithaya R. Multifaceted Housekeeping Functions of Autophagy. J Indian Inst Sci 2017. [DOI: 10.1007/s41745-016-0015-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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65
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Chen CH, Lo RW, Urban D, Pluthero FG, Kahr WHA. α-granule biogenesis: from disease to discovery. Platelets 2017; 28:147-154. [DOI: 10.1080/09537104.2017.1280599] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Chang Hua Chen
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| | - Richard W. Lo
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| | - Denisa Urban
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| | - Fred G. Pluthero
- Cell Biology Program, Research Institute, Hospital for Sick Children, Toronto, ON, Canada
| | - Walter H. A. Kahr
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada
- Cell Biology Program, Research Institute, Hospital for Sick Children, Toronto, ON, Canada
- Division of Haematology/Oncology, Department of Paediatrics, University of Toronto and The Hospital for Sick Children, Toronto, ON, Canada
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66
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Charcot Marie Tooth 2B Peripheral Sensory Neuropathy: How Rab7 Mutations Impact NGF Signaling? Int J Mol Sci 2017; 18:ijms18020324. [PMID: 28165391 PMCID: PMC5343860 DOI: 10.3390/ijms18020324] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Revised: 01/10/2017] [Accepted: 01/15/2017] [Indexed: 12/12/2022] Open
Abstract
Charcot-Marie-Tooth 2B peripheral sensory neuropathy (CMT2B) is a debilitating autosomal dominant hereditary sensory neuropathy. Patients with this disease lose pain sensation and frequently need amputation. Axonal dysfunction and degeneration of peripheral sensory neurons is a major clinical manifestation of CMT2B. However, the cellular and molecular pathogenic mechanisms remain undefined. CMT2B is caused by missense point mutations (L129F, K157N, N161T/I, V162M) in Rab7 GTPase. Strong evidence suggests that the Rab7 mutation(s) enhances the cellular levels of activated Rab7 proteins, thus resulting in increased lysosomal activity and autophagy. As a consequence, trafficking and signaling of neurotrophic factors such as nerve growth factor (NGF) in the long axons of peripheral sensory neurons are particularly vulnerable to premature degradation. A “gain of toxicity” model has, thus, been proposed based on these observations. However, studies of fly photo-sensory neurons indicate that the Rab7 mutation(s) causes a “loss of function”, resulting in haploinsufficiency. In the review, we summarize experimental evidence for both hypotheses. We argue that better models (rodent animals and human neurons) of CMT2B are needed to precisely define the disease mechanisms.
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67
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Reggiori F, Ungermann C. Autophagosome Maturation and Fusion. J Mol Biol 2017; 429:486-496. [DOI: 10.1016/j.jmb.2017.01.002] [Citation(s) in RCA: 119] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Revised: 01/03/2017] [Accepted: 01/04/2017] [Indexed: 02/07/2023]
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68
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Lürick A, Gao J, Kuhlee A, Yavavli E, Langemeyer L, Perz A, Raunser S, Ungermann C. Multivalent Rab interactions determine tether-mediated membrane fusion. Mol Biol Cell 2016; 28:322-332. [PMID: 27852901 PMCID: PMC5231900 DOI: 10.1091/mbc.e16-11-0764] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Accepted: 11/10/2016] [Indexed: 12/22/2022] Open
Abstract
Membrane fusion at endomembranes requires cross-talk between Rab GTPases and tethers to drive SNARE-mediated lipid bilayer mixing. Several tethers have multiple Rab-binding sites with largely untested function. Here we dissected the lysosomal HOPS complex as a tethering complex with just two binding sites for the Rab7-like Ypt7 protein to determine their relevance for fusion. Using tethering and fusion assays combined with HOPS mutants, we show that HOPS-dependent fusion requires both Rab-binding sites, with Vps39 being the stronger Ypt7 interactor than Vps41. The intrinsic amphipathic lipid packaging sensor (ALPS) motif within HOPS Vps41, a target of the vacuolar kinase Yck3, is dispensable for tethering and fusion but can affect tethering if phosphorylated. In combination, our data demonstrate that a multivalent tethering complex uses its two Rab bindings to determine the place of SNARE assembly and thus fusion at endomembranes.
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Affiliation(s)
- Anna Lürick
- Biochemistry Section, Department of Biology/Chemistry, University of Osnabrück, 49076 Osnabrück, Germany
| | - Jieqiong Gao
- Biochemistry Section, Department of Biology/Chemistry, University of Osnabrück, 49076 Osnabrück, Germany
| | - Anne Kuhlee
- Department of Physical Biochemistry, Max-Planck Institute of Molecular Physiology; 44227 Dortmund, Germany
| | - Erdal Yavavli
- Biochemistry Section, Department of Biology/Chemistry, University of Osnabrück, 49076 Osnabrück, Germany
| | - Lars Langemeyer
- Biochemistry Section, Department of Biology/Chemistry, University of Osnabrück, 49076 Osnabrück, Germany
| | - Angela Perz
- Biochemistry Section, Department of Biology/Chemistry, University of Osnabrück, 49076 Osnabrück, Germany
| | - Stefan Raunser
- Department of Physical Biochemistry, Max-Planck Institute of Molecular Physiology; 44227 Dortmund, Germany
| | - Christian Ungermann
- Biochemistry Section, Department of Biology/Chemistry, University of Osnabrück, 49076 Osnabrück, Germany
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69
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Pu J, Guardia CM, Keren-Kaplan T, Bonifacino JS. Mechanisms and functions of lysosome positioning. J Cell Sci 2016; 129:4329-4339. [PMID: 27799357 DOI: 10.1242/jcs.196287] [Citation(s) in RCA: 276] [Impact Index Per Article: 34.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Lysosomes have been classically considered terminal degradative organelles, but in recent years they have been found to participate in many other cellular processes, including killing of intracellular pathogens, antigen presentation, plasma membrane repair, cell adhesion and migration, tumor invasion and metastasis, apoptotic cell death, metabolic signaling and gene regulation. In addition, lysosome dysfunction has been shown to underlie not only rare lysosome storage disorders but also more common diseases, such as cancer and neurodegeneration. The involvement of lysosomes in most of these processes is now known to depend on the ability of lysosomes to move throughout the cytoplasm. Here, we review recent findings on the mechanisms that mediate the motility and positioning of lysosomes, and the importance of lysosome dynamics for cell physiology and pathology.
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Affiliation(s)
- Jing Pu
- Cell Biology and Neurobiology Branch, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - 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
| | - Tal Keren-Kaplan
- 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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70
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Gengyo-Ando K, Kage-Nakadai E, Yoshina S, Otori M, Kagawa-Nagamura Y, Nakai J, Mitani S. Distinct roles of the two VPS33 proteins in the endolysosomal system in Caenorhabditis elegans. Traffic 2016; 17:1197-1213. [PMID: 27558849 DOI: 10.1111/tra.12430] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Revised: 08/18/2016] [Accepted: 08/18/2016] [Indexed: 02/02/2023]
Abstract
Sec1/Munc-18 (SM) family proteins are essential regulators in intracellular transport in eukaryotic cells. The SM protein Vps33 functions as a core subunit of two tethering complexes, class C core vacuole/endosome tethering (CORVET) and homotypic fusion and vacuole protein sorting (HOPS) in the endocytic pathway in yeast. Metazoan cells possess two Vps33 proteins, VPS33A and VPS33B, but their precise roles remain unknown. Here, we present a comparative analysis of Caenorhabditis elegans null mutants for these proteins. We found that the vps-33.1 (VPS33A) mutants exhibited severe defects in both endocytic function and endolysosomal biogenesis in scavenger cells. Furthermore, vps-33.1 mutations caused endocytosis defects in other tissues, and the loss of maternal and zygotic VPS-33.1 resulted in embryonic lethality. By contrast, vps-33.2 mutants were viable but sterile, with terminally arrested spermatocytes. The spermatogenesis phenotype suggests that VPS33.2 is involved in the formation of a sperm-specific organelle. The endocytosis defect in the vps-33.1 mutant was not restored by the expression of VPS-33.2, which indicates that these proteins have nonredundant functions. Together, our data suggest that VPS-33.1 shares most of the general functions of yeast Vps33 in terms of tethering complexes in the endolysosomal system, whereas VPS-33.2 has tissue/organelle specific functions in C. elegans.
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Affiliation(s)
- Keiko Gengyo-Ando
- Department of Physiology, Tokyo Women's Medical University School of Medicine, Tokyo, Japan. .,Brain and Body System Science Institute, Saitama University, Saitama, Japan. .,Graduate School of Science and Engineering, Saitama University, Saitama, Japan.
| | - Eriko Kage-Nakadai
- Department of Physiology, Tokyo Women's Medical University School of Medicine, Tokyo, Japan.,The OCU Advanced Research Institute for Natural Science and Technology, Osaka City University, Osaka, Japan
| | - Sawako Yoshina
- Department of Physiology, Tokyo Women's Medical University School of Medicine, Tokyo, Japan
| | - Muneyoshi Otori
- Department of Physiology, Tokyo Women's Medical University School of Medicine, Tokyo, Japan
| | - Yuko Kagawa-Nagamura
- Brain and Body System Science Institute, Saitama University, Saitama, Japan.,Graduate School of Science and Engineering, Saitama University, Saitama, Japan
| | - Junichi Nakai
- Brain and Body System Science Institute, Saitama University, Saitama, Japan.,Graduate School of Science and Engineering, Saitama University, Saitama, Japan
| | - Shohei Mitani
- Department of Physiology, Tokyo Women's Medical University School of Medicine, Tokyo, Japan.
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71
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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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72
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Klinger CM, Ramirez-Macias I, Herman EK, Turkewitz AP, Field MC, Dacks JB. Resolving the homology-function relationship through comparative genomics of membrane-trafficking machinery and parasite cell biology. Mol Biochem Parasitol 2016; 209:88-103. [PMID: 27444378 PMCID: PMC5140719 DOI: 10.1016/j.molbiopara.2016.07.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Revised: 07/12/2016] [Accepted: 07/16/2016] [Indexed: 10/21/2022]
Abstract
With advances in DNA sequencing technology, it is increasingly common and tractable to informatically look for genes of interest in the genomic databases of parasitic organisms and infer cellular states. Assignment of a putative gene function based on homology to functionally characterized genes in other organisms, though powerful, relies on the implicit assumption of functional homology, i.e. that orthology indicates conserved function. Eukaryotes reveal a dazzling array of cellular features and structural organization, suggesting a concomitant diversity in their underlying molecular machinery. Significantly, examples of novel functions for pre-existing or new paralogues are not uncommon. Do these examples undermine the basic assumption of functional homology, especially in parasitic protists, which are often highly derived? Here we examine the extent to which functional homology exists between organisms spanning the eukaryotic lineage. By comparing membrane trafficking proteins between parasitic protists and traditional model organisms, where direct functional evidence is available, we find that function is indeed largely conserved between orthologues, albeit with significant adaptation arising from the unique biological features within each lineage.
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Affiliation(s)
- Christen M Klinger
- Department of Cell Biology, University of Alberta, Edmonton, Alberta, Canada
| | | | - Emily K Herman
- Department of Cell Biology, University of Alberta, Edmonton, Alberta, Canada
| | - Aaron P Turkewitz
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL, USA
| | - Mark C Field
- School of Life Sciences, University of Dundee, Dundee, UK
| | - Joel B Dacks
- Department of Cell Biology, University of Alberta, Edmonton, Alberta, Canada.
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73
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Flores-Toro JA, Go KL, Leeuwenburgh C, Kim JS. Autophagy in the liver: cell's cannibalism and beyond. Arch Pharm Res 2016; 39:1050-61. [PMID: 27515049 DOI: 10.1007/s12272-016-0807-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Accepted: 08/02/2016] [Indexed: 02/06/2023]
Abstract
Chronic liver disease and its progression to liver failure are induced by various etiologies including viral infection, alcoholic and nonalcoholic hepatosteatosis. It is anticipated that the prevalence of fatty liver disease will continue to rise due to the growing incidence of obesity and metabolic disorder. Evidence is accumulating to indicate that the onset of fatty liver disease is causatively linked to mitochondrial dysfunction and abnormal lipid accumulation. Current treatment options for this disease are limited. Autophagy is an integral catabolic pathway that maintains cellular homeostasis both selectively and nonselectively. As mitophagy and lipophagy selectively remove dysfunctional mitochondria and excess lipids, respectively, stimulation of autophagy could have therapeutic potential to ameliorate liver function in steatotic patients. This review highlights our up-to-date knowledge on mechanistic roles of autophagy in the pathogenesis of fatty liver disease and its vulnerability to surgical stress, with an emphasis on mitophagy and lipophagy.
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Affiliation(s)
- Joseph A Flores-Toro
- Department of Surgery, University of Florida, R4-204 ARB, 1600 SW Archer Rd, Gainesville, FL, 32610, USA
| | - Kristina L Go
- Department of Surgery, University of Florida, R4-204 ARB, 1600 SW Archer Rd, Gainesville, FL, 32610, USA
| | - Christiaan Leeuwenburgh
- Department of Aging and Geriatric Research, University of Florida, Gainesville, FL, 32610, USA
- Institute on Aging, University of Florida, Gainesville, FL, 32610, USA
| | - Jae-Sung Kim
- Department of Surgery, University of Florida, R4-204 ARB, 1600 SW Archer Rd, Gainesville, FL, 32610, USA.
- Institute on Aging, University of Florida, Gainesville, FL, 32610, USA.
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74
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Abstract
Mutations in PARK2 (parkin), which encodes Parkin protein, an E3 ubiquitin ligase, are associated with autosomal recessive early-onset Parkinson's disease (PD). While several studies implicated Parkin in the regulation of mitophagy and proteasomal degradation, the precise mechanism leading to neurodegeneration upon Parkin loss of function remains incompletely understood. In this study, we found that Parkin modulates the endocytic pathway through the regulation of endosomal structure and function. We showed that loss of Parkin function led to decreased endosomal tubulation and membrane association of vesicle protein sorting 35 (VPS35) and sorting nexin 1 (SNX1), as well as decreased mannose 6 phosphate receptor (M6PR), suggesting the impairment of retromer pathway in Parkin-deficient cells. We also found increased formation of intraluminal vesicles coupled with enhanced release of exosomes in the presence of mutant Parkin. To elucidate the molecular mechanism of these alterations in the endocytic pathway in Parkin-deficient cells, we found that Parkin regulates the levels and activity of Rab7 by promoting its ubiquitination on lysine 38 residue. Both endogenous Rab7 in Parkin-deficient cells and overexpressed K38 R-Rab7 mutant displayed decreased effector binding and membrane association. Furthermore, overexpression of K38R-Rab7 in HEK293 cells phenocopied the increased secretion of exosomes observed in Parkin-deficient cells, suggesting that Rab7 deregulation may be at least partially responsible for the endocytic phenotype observed in Parkin-deficient cells. These findings establish a role for Parkin in regulating the endo-lysosomal pathway and retromer function and raise the possibility that alterations in these pathways contribute to the development of pathology in Parkin-linked Parkinson's disease.
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75
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Lőrincz P, Lakatos Z, Varga Á, Maruzs T, Simon-Vecsei Z, Darula Z, Benkő P, Csordás G, Lippai M, Andó I, Hegedűs K, Medzihradszky KF, Takáts S, Juhász G. MiniCORVET is a Vps8-containing early endosomal tether in Drosophila. eLife 2016; 5. [PMID: 27253064 PMCID: PMC4935465 DOI: 10.7554/elife.14226] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Accepted: 06/01/2016] [Indexed: 01/06/2023] Open
Abstract
Yeast studies identified two heterohexameric tethering complexes, which consist of 4 shared (Vps11, Vps16, Vps18 and Vps33) and 2 specific subunits: Vps3 and Vps8 (CORVET) versus Vps39 and Vps41 (HOPS). CORVET is an early and HOPS is a late endosomal tether. The function of HOPS is well known in animal cells, while CORVET is poorly characterized. Here we show that Drosophila Vps8 is highly expressed in hemocytes and nephrocytes, and localizes to early endosomes despite the lack of a clear Vps3 homolog. We find that Vps8 forms a complex and acts together with Vps16A, Dor/Vps18 and Car/Vps33A, and loss of any of these proteins leads to fragmentation of endosomes. Surprisingly, Vps11 deletion causes enlargement of endosomes, similar to loss of the HOPS-specific subunits Vps39 and Lt/Vps41. We thus identify a 4 subunit-containing miniCORVET complex as an unconventional early endosomal tether in Drosophila. DOI:http://dx.doi.org/10.7554/eLife.14226.001
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Affiliation(s)
- Péter Lőrincz
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest, Hungary
| | - Zsolt Lakatos
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest, Hungary
| | - Ágnes Varga
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest, Hungary
| | - Tamás Maruzs
- Institute of Genetics, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - Zsófia Simon-Vecsei
- Institute of Genetics, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - Zsuzsanna Darula
- Laboratory of Proteomics Research, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - Péter Benkő
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest, Hungary
| | - Gábor Csordás
- Institute of Genetics, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - Mónika Lippai
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest, Hungary
| | - István Andó
- Institute of Genetics, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - Krisztina Hegedűs
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest, Hungary
| | - Katalin F Medzihradszky
- Laboratory of Proteomics Research, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - Szabolcs Takáts
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest, Hungary
| | - Gábor Juhász
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest, Hungary.,Institute of Genetics, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
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76
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Yang X, Cui H, Cheng J, Xie J, Jiang D, Hsiang T, Fu Y. A HOPS protein, CmVps39, is required for vacuolar morphology, autophagy, growth, conidiogenesis and mycoparasitic functions of Coniothyrium minitans. Environ Microbiol 2016; 18:3785-3797. [PMID: 27105005 DOI: 10.1111/1462-2920.13334] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Coniothyrium minitans is an important sclerotial and hyphal parasite of the plant pathogen Sclerotinia sclerotiorum. Previously, a conidiation-deficient mutant, ZS-1N22225, was screened from a T-DNA insertional library of C. minitans. CmVps39, a homologue of Vam6p/Vps39p that plays a critical role in vacuolar morphogenesis in yeast, was disrupted by a T-DNA insertion in this mutant. CmVps39 is composed of 1071 amino acids with an amino-terminal citron homology domain and a central clathrin homology domain, as observed for other Vam6p/Vps39p family proteins. Abnormal fragmented vacuoles were observed in ΔCmVps39 under light microscopy and transmission electron microscopy, and ΔCmVps39 showed impairment in autophagy. ΔCmVps39 also exhibited significantly reduced hyphal development, poor conidiation and decreased sclerotial mycoparasitism. In addition, deletion of CmVps39 affected osmotic adaptation, pH homeostasis and cell wall integrity. Taken together, our results suggest that CmVps39 has an essential function in vacuolar morphology, autophagy, fungal development and mycoparasitism in C. minitans.
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Affiliation(s)
- Xiaoxiang Yang
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070, Hubei Province, People's Republic of China.,The Provincial Key Lab of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, Hubei Province, People's Republic of China
| | - Hui Cui
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070, Hubei Province, People's Republic of China.,The Provincial Key Lab of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, Hubei Province, People's Republic of China
| | - Jiasen Cheng
- The Provincial Key Lab of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, Hubei Province, People's Republic of China
| | - Jiatao Xie
- The Provincial Key Lab of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, Hubei Province, People's Republic of China
| | - Daohong Jiang
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070, Hubei Province, People's Republic of China.,The Provincial Key Lab of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, Hubei Province, People's Republic of China
| | - Tom Hsiang
- Department of Environmental Biology, University of Guelph, Guelph, ON, Canada
| | - Yanping Fu
- The Provincial Key Lab of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, Hubei Province, People's Republic of China
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77
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Ishida M, E Oguchi M, Fukuda M. Multiple Types of Guanine Nucleotide Exchange Factors (GEFs) for Rab Small GTPases. Cell Struct Funct 2016; 41:61-79. [PMID: 27246931 DOI: 10.1247/csf.16008] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Rab small GTPases are highly conserved master regulators of membrane traffic in all eukaryotes. The same as the activation and inactivation of other small GTPases, the activation and inactivation of Rabs are tightly controlled by specific GEFs (guanine nucleotide exchange factors) and GAPs (GTPase-activating proteins), respectively. Although almost all Rab-GAPs reported thus far have a TBC (Tre-2/Bub2/Cdc16)/Rab-GAP domain in common, recent accumulating evidence has indicated the existence of a number of structurally unrelated types of Rab-GEFs, including DENN proteins, VPS9 proteins, Sec2 proteins, TRAPP complexes, heterodimer GEFs (Mon1-Ccz1, HPS1-HPS4 (BLOC-3 complex), Ric1-Rgp1 and Rab3GAP1/2), and other GEFs (e.g., REI-1 and RPGR). In this review article we provide an up-to-date overview of the structures and functions of all putative Rab-GEFs in mammals, with a special focus on their substrate Rabs, interacting proteins, associations with genetic diseases, and intracellular localizations.
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Affiliation(s)
- Morié Ishida
- Laboratory of Membrane Trafficking Mechanisms, Department of Developmental Biology and Neurosciences, Graduate School of Life Sciences, Tohoku University
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78
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Dubuke ML, Munson M. The Secret Life of Tethers: The Role of Tethering Factors in SNARE Complex Regulation. Front Cell Dev Biol 2016; 4:42. [PMID: 27243006 PMCID: PMC4860414 DOI: 10.3389/fcell.2016.00042] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Accepted: 04/25/2016] [Indexed: 02/03/2023] Open
Abstract
Trafficking in eukaryotic cells is a tightly regulated process to ensure correct cargo delivery to the proper destination organelle or plasma membrane. In this review, we focus on how the vesicle fusion machinery, the SNARE complex, is regulated by the interplay of the multisubunit tethering complexes (MTC) with the SNAREs and Sec1/Munc18 (SM) proteins. Although these factors are used in different stages of membrane trafficking, e.g., Golgi to plasma membrane transport vs. vacuolar fusion, and in a variety of diverse eukaryotic cell types, many commonalities between their functions are being revealed. We explore the various protein-protein interactions and findings from functional reconstitution studies in order to highlight both their common features and the differences in their modes of regulation. These studies serve as a starting point for mechanistic explorations in other systems.
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Affiliation(s)
- Michelle L Dubuke
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School Worcester, MA USA
| | - Mary Munson
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School Worcester, MA USA
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79
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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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80
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Toh WH, Gleeson PA. Emerging Insights into the Roles of Membrane Tethers from Analysis of Whole Organisms: The Tip of an Iceberg? Front Cell Dev Biol 2016; 4:12. [PMID: 26973835 PMCID: PMC4770024 DOI: 10.3389/fcell.2016.00012] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2015] [Accepted: 02/08/2016] [Indexed: 12/02/2022] Open
Abstract
Membrane tethers have been identified throughout different compartments of the endomembrane system. It is now well established that a number of membrane tethers mediate docking of membrane carriers in anterograde and retrograde transport and in regulating the organization of membrane compartments. Much of our information on membrane tethers have been obtained from the analysis of individual membrane tethers in cultured cells. In the future it will be important to better appreciate the network of interactions mediated by tethers and the potential co-ordination of their collective functions in vivo. There are now a number of studies which have analyzed membrane tethers in tissues and organisms which are providing new insights into the role of this class of membrane protein at the physiological level. Here we review recent advances in the understanding of the function of membrane tethers from knock outs (or knock downs) in whole organisms and from mutations in tethers associated with disease.
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Affiliation(s)
- Wei Hong Toh
- The Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne Melbourne, VIC, Australia
| | - Paul A Gleeson
- The Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne Melbourne, VIC, Australia
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81
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Galmes R, ten Brink C, Oorschot V, Veenendaal T, Jonker C, van der Sluijs P, Klumperman J. Vps33B is required for delivery of endocytosed cargo to lysosomes. Traffic 2015; 16:1288-305. [DOI: 10.1111/tra.12334] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Revised: 09/16/2015] [Accepted: 09/16/2015] [Indexed: 12/23/2022]
Affiliation(s)
- Romain Galmes
- Department of Cell Biology and Institute of Biomembranes; Center for Molecular Medicine, University Medical Center Utrecht; Heidelberglaan 100 3584CX Utrecht The Netherlands
- Present address: Institut Jacques Monod; CNRS, UMR7592, Université Paris Diderot; Sorbonne Paris Cité F-75013 Paris France
| | - Corlinda ten Brink
- Department of Cell Biology and Institute of Biomembranes; Center for Molecular Medicine, University Medical Center Utrecht; Heidelberglaan 100 3584CX Utrecht The Netherlands
| | - Viola Oorschot
- Department of Cell Biology and Institute of Biomembranes; Center for Molecular Medicine, University Medical Center Utrecht; Heidelberglaan 100 3584CX Utrecht The Netherlands
- Present address: Monash Micro Imaging; 15 Innovation Walk, Strip 1 Monash Biotechnology, Monash University; Clayton VIC 3800 Australia
| | - Tineke Veenendaal
- Department of Cell Biology and Institute of Biomembranes; Center for Molecular Medicine, University Medical Center Utrecht; Heidelberglaan 100 3584CX Utrecht The Netherlands
| | - Caspar Jonker
- Department of Cell Biology and Institute of Biomembranes; Center for Molecular Medicine, University Medical Center Utrecht; Heidelberglaan 100 3584CX Utrecht The Netherlands
| | - Peter van der Sluijs
- Department of Cell Biology and Institute of Biomembranes; Center for Molecular Medicine, University Medical Center Utrecht; Heidelberglaan 100 3584CX Utrecht The Netherlands
| | - Judith Klumperman
- Department of Cell Biology and Institute of Biomembranes; Center for Molecular Medicine, University Medical Center Utrecht; Heidelberglaan 100 3584CX Utrecht The Netherlands
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82
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van der Kant R, Jonker CTH, Wijdeven RH, Bakker J, Janssen L, Klumperman J, Neefjes J. Characterization of the Mammalian CORVET and HOPS Complexes and Their Modular Restructuring for Endosome Specificity. J Biol Chem 2015; 290:30280-90. [PMID: 26463206 DOI: 10.1074/jbc.m115.688440] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Indexed: 01/30/2023] Open
Abstract
Trafficking of cargo through the endosomal system depends on endosomal fusion events mediated by SNARE proteins, Rab-GTPases, and multisubunit tethering complexes. The CORVET and HOPS tethering complexes, respectively, regulate early and late endosomal tethering and have been characterized in detail in yeast where their sequential membrane targeting and assembly is well understood. Mammalian CORVET and HOPS subunits significantly differ from their yeast homologues, and novel proteins with high homology to CORVET/HOPS subunits have evolved. However, an analysis of the molecular interactions between these subunits in mammals is lacking. Here, we provide a detailed analysis of interactions within the mammalian CORVET and HOPS as well as an additional endosomal-targeting complex (VIPAS39-VPS33B) that does not exist in yeast. We show that core interactions within CORVET and HOPS are largely conserved but that the membrane-targeting module in HOPS has significantly changed to accommodate binding to mammalian-specific RAB7 interacting lysosomal protein (RILP). Arthrogryposis-renal dysfunction-cholestasis (ARC) syndrome-associated mutations in VPS33B selectively disrupt recruitment to late endosomes by RILP or binding to its partner VIPAS39. Within the shared core of CORVET/HOPS, we find that VPS11 acts as a molecular switch that binds either CORVET-specific TGFBRAP1 or HOPS-specific VPS39/RILP thereby allowing selective targeting of these tethering complexes to early or late endosomes to time fusion events in the endo/lysosomal pathway.
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Affiliation(s)
- Rik van der Kant
- From the Division of Cell Biology, Netherlands Cancer Institute, Amsterdam, 1066 CX, The Netherlands and
| | - Caspar T H Jonker
- Department of Cell Biology, Center of Molecular Medicine, Utrecht, 3584 CX, The Netherlands
| | - Ruud H Wijdeven
- From the Division of Cell Biology, Netherlands Cancer Institute, Amsterdam, 1066 CX, The Netherlands and
| | - Jeroen Bakker
- From the Division of Cell Biology, Netherlands Cancer Institute, Amsterdam, 1066 CX, The Netherlands and
| | - Lennert Janssen
- From the Division of Cell Biology, Netherlands Cancer Institute, Amsterdam, 1066 CX, The Netherlands and
| | - Judith Klumperman
- Department of Cell Biology, Center of Molecular Medicine, Utrecht, 3584 CX, The Netherlands
| | - Jacques Neefjes
- From the Division of Cell Biology, Netherlands Cancer Institute, Amsterdam, 1066 CX, The Netherlands and
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83
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Aittaleb M, Chen PJ, Akaaboune M. Failure of lysosome clustering and positioning in the juxtanuclear region in cells deficient in rapsyn. J Cell Sci 2015; 128:3744-56. [PMID: 26330529 DOI: 10.1242/jcs.172536] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Accepted: 08/23/2015] [Indexed: 01/06/2023] Open
Abstract
Rapsyn, a scaffold protein, is required for the clustering of acetylcholine receptors (AChRs) at contacts between motor neurons and differentiating muscle cells. Rapsyn is also expressed in cells that do not express AChRs. However, its function in these cells remains unknown. Here, we show that rapsyn plays an AChR-independent role in organizing the distribution and mobility of lysosomes. In cells devoid of AChRs, rapsyn selectively induces the clustering of lysosomes at high density in the juxtanuclear region without affecting the distribution of other intracellular organelles. However, when the same cells overexpress AChRs, rapsyn is recruited away from lysosomes to colocalize with AChR clusters on the cell surface. In rapsyn-deficient (Rapsn(-/-)) myoblasts or cells overexpressing rapsyn mutants, lysosomes are scattered within the cell and highly dynamic. The increased mobility of lysosomes in Rapsn(-/-) cells is associated with a significant increase in lysosomal exocytosis, as evidenced by increased release of lysosomal enzymes and plasma membrane damage when cells were challenged with the bacterial pore-forming toxin streptolysin-O. These findings uncover a new link between rapsyn, lysosome positioning, exocytosis and plasma membrane integrity.
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Affiliation(s)
- Mohamed Aittaleb
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Po-Ju Chen
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Mohammed Akaaboune
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA Program in Neuroscience, University of Michigan, Ann Arbor, MI 48109, USA
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84
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Edvardson S, Gerhard F, Jalas C, Lachmann J, Golan D, Saada A, Shaag A, Ungermann C, Elpeleg O. Hypomyelination and developmental delay associated with VPS11 mutation in Ashkenazi-Jewish patients. J Med Genet 2015; 52:749-53. [PMID: 26307567 DOI: 10.1136/jmedgenet-2015-103239] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2015] [Accepted: 08/03/2015] [Indexed: 12/16/2022]
Abstract
BACKGROUND The genetic heterogeneity of developmental delay and cognitive impairment is vast. The endocytic network is essential for neural development and synaptic plasticity by regulating the sorting of numerous transmembrane proteins. Disruption of the pathway can lead to neuronal pathology. Endosomal biogenesis relies on two Rab proteins, Rab5 and Rab7, which bind to two hexameric tethering complexes, the endosomal class C core vacuole/endosome tethering complex (CORVET) and the late endosomal/lysosomal homotypic fusion and protein sorting complex (HOPS). Both complexes consist of four core proteins and differ by their specific Rab-binding proteins. OBJECTIVES To identify the molecular basis of a neurological disease, which consists of global developmental stagnation at 3-8 months, increasing appendicular spasticity, truncal hypotonia and acquired microcephaly, with variable seizure disorder, accompanied by thin corpus callosum, paucity of white matter and delayed myelination in eight patients from four unrelated Ashkenazi-Jewish (AJ) families. METHODS Exome analysis, homozygosity mapping and Mup1-GFP transport assay in mutant yeast. RESULTS Homozygosity for a missense mutation, p.Cys846Gly, in one of the endosomal biogenesis core proteins, VPS11, was identified in all the patients. This was shown to be a founder mutation with a carrier frequency of 0.6% in the AJ population. The homologous yeast mutant had moderate impairment of fusion of the late endosome to the vacuole in Mup1-GFP transport assay. CONCLUSIONS We speculate that in neuronal cells, impairment of fusion of the late endosome to the vacuole would attenuate the degradation of plasma membrane receptors, thereby underlying the progressive neuronal phenotype in our patients. The VPS11 p.Cys846Gly mutation should be added to the AJ carrier screening panel.
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Affiliation(s)
- Shimon Edvardson
- Monique and Jacques Roboh Department of Genetic Research, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Frank Gerhard
- Department of Biology/Chemistry, Biochemistry Section, University of Osnabrück, Osnabrück, Germany
| | - Chaim Jalas
- Bonei Olam, Center for Rare Jewish Genetic Disorders, Brooklyn, New York, USA
| | - Jens Lachmann
- Department of Biology/Chemistry, Biochemistry Section, University of Osnabrück, Osnabrück, Germany
| | - Dafna Golan
- Maccabi Health Services, Child Development Center, Jerusalem, Israel
| | - Ann Saada
- Monique and Jacques Roboh Department of Genetic Research, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Avraham Shaag
- Monique and Jacques Roboh Department of Genetic Research, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Christian Ungermann
- Department of Biology/Chemistry, Biochemistry Section, University of Osnabrück, Osnabrück, Germany
| | - Orly Elpeleg
- Monique and Jacques Roboh Department of Genetic Research, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
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85
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Ho R, Stroupe C. The HOPS/class C Vps complex tethers membranes by binding to one Rab GTPase in each apposed membrane. Mol Biol Cell 2015; 26:2655-63. [PMID: 25995379 PMCID: PMC4501362 DOI: 10.1091/mbc.e14-04-0922] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2014] [Revised: 05/13/2015] [Accepted: 05/15/2015] [Indexed: 11/30/2022] Open
Abstract
Many Rab GTPase effectors are membrane-tethering factors, that is, they physically link two apposed membranes before intracellular membrane fusion. In this study, we investigate the distinct binding factors needed on apposed membranes for Rab effector-dependent tethering. We show that the homotypic fusion and protein-sorting/class C vacuole protein-sorting (HOPS/class C Vps) complex can tether low-curvature membranes, that is, liposomes with a diameter of ∼100 nm, only when the yeast vacuolar Rab GTPase Ypt7p is present in both tethered membranes. When HOPS is phosphorylated by the vacuolar casein kinase I, Yck3p, tethering only takes place when GTP-bound Ypt7p is present in both tethered membranes. When HOPS is not phosphorylated, however, its tethering activity shows little specificity for the nucleotide-binding state of Ypt7p. These results suggest a model for HOPS-mediated tethering in which HOPS tethers membranes by binding to Ypt7p in each of the two tethered membranes. Moreover, because vacuole-associated HOPS is presumably phosphorylated by Yck3p, our results suggest that nucleotide exchange of Ypt7p on multivesicular bodies (MVBs)/late endosomes must take place before HOPS can mediate tethering at vacuoles.
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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 22908
| | - Christopher Stroupe
- Department of Molecular Physiology and Biological Physics and Center for Membrane Biology, University of Virginia School of Medicine, Charlottesville, VA 22908
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86
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Wartosch L, Günesdogan U, Graham SC, Luzio JP. Recruitment of VPS33A to HOPS by VPS16 Is Required for Lysosome Fusion with Endosomes and Autophagosomes. Traffic 2015; 16:727-42. [PMID: 25783203 PMCID: PMC4510706 DOI: 10.1111/tra.12283] [Citation(s) in RCA: 105] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Revised: 03/12/2015] [Accepted: 03/12/2015] [Indexed: 12/17/2022]
Abstract
The mammalian homotypic fusion and vacuole protein sorting (HOPS) complex is comprised of six subunits: VPS11, VPS16, VPS18, VPS39, VPS41 and the Sec1/Munc18 (SM) family member VPS33A. Human HOPS has been predicted to be a tethering complex required for fusion of intracellular compartments with lysosomes, but it remains unclear whether all HOPS subunits are required. We showed that the whole HOPS complex is required for fusion of endosomes with lysosomes by monitoring the delivery of endocytosed fluorescent dextran to lysosomes in cells depleted of individual HOPS proteins. We used the crystal structure of the VPS16/VPS33A complex to design VPS16 and VPS33A mutants that no longer bind each other and showed that, unlike the wild-type proteins, these mutants no longer rescue lysosome fusion with endosomes or autophagosomes in cells depleted of the endogenous proteins. There was no effect of depleting either VIPAR or VPS33B, paralogs of VPS16 and VPS33A, on fusion of lysosomes with either endosomes or autophagosomes and immunoprecipitation showed that they form a complex distinct from HOPS. Our data demonstrate the necessity of recruiting the SM protein VPS33A to HOPS via its interaction with VPS16 and that HOPS proteins, but not VIPAR or VPS33B, are essential for fusion of endosomes or autophagosomes with lysosomes.
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Affiliation(s)
- Lena Wartosch
- Cambridge Institute for Medical Research and Department of Clinical Biochemistry, Wellcome Trust/MRC BuildingUniversity of CambridgeCambridgeCB2 0XYUK
| | - Ufuk Günesdogan
- Wellcome Trust/Cancer Research UK Gurdon InstituteUniversity of CambridgeCambridgeCB2 1QNUK
| | | | - J. Paul Luzio
- Cambridge Institute for Medical Research and Department of Clinical Biochemistry, Wellcome Trust/MRC BuildingUniversity of CambridgeCambridgeCB2 0XYUK
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87
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Liu XH, Chen SM, Gao HM, Ning GA, Shi HB, Wang Y, Dong B, Qi YY, Zhang DM, Lu GD, Wang ZH, Zhou J, Lin FC. The small GTPase MoYpt7 is required for membrane fusion in autophagy and pathogenicity ofMagnaporthe oryzae. Environ Microbiol 2015; 17:4495-510. [DOI: 10.1111/1462-2920.12903] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2015] [Revised: 05/07/2015] [Accepted: 05/10/2015] [Indexed: 12/31/2022]
Affiliation(s)
- Xiao-Hong Liu
- State Key Laboratory for Rice Biology; Biotechnology Institute; Zhejiang University; Hangzhou 310058 China
| | - Si-Miao Chen
- College of Life Sciences; Fujian Agriculture and Forestry University; Fuzhou Fujian 350002 China
| | - Hui-Min Gao
- State Key Laboratory of Soil and Sustainable Agriculture; Institute of Soil Science; Chinese Academy Sciences; Nanjing 210008 China
| | - Guo-Ao Ning
- State Key Laboratory for Rice Biology; Biotechnology Institute; Zhejiang University; Hangzhou 310058 China
| | - Huan-Bin Shi
- State Key Laboratory for Rice Biology; Biotechnology Institute; Zhejiang University; Hangzhou 310058 China
| | - Yao Wang
- State Key Laboratory for Rice Biology; Biotechnology Institute; Zhejiang University; Hangzhou 310058 China
| | - Bo Dong
- Institute of Virology and Biotechnology; Zhejiang Academy of Agricultural Science; Hangzhou 310058 China
| | - Yao-Yao Qi
- Key Laboratory of Biopesticides and Chemical Biology; Ministry of Education; Fujian Agriculture and Forestry University; Fuzhou Fujian 350002 China
| | - Dong-Mei Zhang
- Key Laboratory of Biopesticides and Chemical Biology; Ministry of Education; Fujian Agriculture and Forestry University; Fuzhou Fujian 350002 China
| | - Guo-Dong Lu
- Key Laboratory of Biopesticides and Chemical Biology; Ministry of Education; Fujian Agriculture and Forestry University; Fuzhou Fujian 350002 China
| | - Zong-Hua Wang
- College of Life Sciences; Fujian Agriculture and Forestry University; Fuzhou Fujian 350002 China
- Key Laboratory of Biopesticides and Chemical Biology; Ministry of Education; Fujian Agriculture and Forestry University; Fuzhou Fujian 350002 China
| | - Jie Zhou
- College of Life Sciences; Fujian Agriculture and Forestry University; Fuzhou Fujian 350002 China
| | - Fu-Cheng Lin
- State Key Laboratory for Rice Biology; Biotechnology Institute; Zhejiang University; Hangzhou 310058 China
- China Tobacco Gene Research Center; Zhengzhou Tobacco Institute of CNTC; Zhengzhou 450001 China
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88
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Kuhlee A, Raunser S, Ungermann C. Functional homologies in vesicle tethering. FEBS Lett 2015; 589:2487-97. [PMID: 26072291 DOI: 10.1016/j.febslet.2015.06.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Revised: 05/30/2015] [Accepted: 06/01/2015] [Indexed: 11/24/2022]
Abstract
The HOPS multisubunit tethering factor (MTC) is a macromolecular protein complex composed of six different subunits. It is one of the key components in the perception and subsequent fusion of multivesicular bodies and vacuoles. Electron microscopy studies indicate structural flexibility of the purified HOPS complex. Inducing higher rigidity into HOPS by biochemically modifying the complex declines the potential to mediate SNARE-driven membrane fusion. Thus, we propose that integral flexibility seems to be not only a feature, but of essential need for the function of HOPS. This review focuses on the general features of membrane tethering and fusion. For this purpose, we compare the structure and mode of action of different tethering factors to highlight their common central features and mechanisms.
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Affiliation(s)
- Anne Kuhlee
- Department of Structural Biochemistry, Max-Planck Institute of Molecular Physiology, Otto-Hahn-Strasse 11, 44227 Dortmund, Germany.
| | - Stefan Raunser
- Department of Structural Biochemistry, Max-Planck Institute of Molecular Physiology, Otto-Hahn-Strasse 11, 44227 Dortmund, Germany
| | - Christian Ungermann
- Department of Biology, University of Osnabrück, Barbarastrasse 13, 49076 Osnabrück, Germany
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89
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Numrich J, Péli-Gulli MP, Arlt H, Sardu A, Griffith J, Levine T, Engelbrecht-Vandré S, Reggiori F, De Virgilio C, Ungermann C. The I-BAR protein Ivy1 is an effector of the Rab7 GTPase Ypt7 involved in vacuole membrane homeostasis. J Cell Sci 2015; 128:2278-92. [PMID: 25999476 DOI: 10.1242/jcs.164905] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Accepted: 05/18/2015] [Indexed: 01/07/2023] Open
Abstract
Membrane fusion at the vacuole depends on a conserved machinery that includes SNAREs, the Rab7 homolog Ypt7 and its effector HOPS. Here, we demonstrate that Ypt7 has an unexpected additional function by controlling membrane homeostasis and nutrient-dependent signaling on the vacuole surface. We show that Ivy1, the yeast homolog of mammalian missing-in-metastasis (MIM), is a vacuolar effector of Ypt7-GTP and interacts with the EGO/ragulator complex, an activator of the target of rapamycin kinase complex 1 (TORC1) on vacuoles. Loss of Ivy1 does not affect EGO vacuolar localization and function. In combination with the deletion of individual subunits of the V-ATPase, however, we observed reduced TORC1 activity and massive enlargement of the vacuole surface. Consistent with this, Ivy1 localizes to invaginations at the vacuole surface and on liposomes in a phosphoinositide- and Ypt7-GTP-controlled manner, which suggests a role in microautophagy. Our data, thus, reveal that Ivy1 is a novel regulator of vacuole membrane homeostasis with connections to TORC1 signaling.
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Affiliation(s)
- Johannes Numrich
- University of Osnabrück, Department of Biology/Chemistry, Biochemistry section, Barbarastrasse 13, 49076 Osnabrück, Germany
| | - Marie-Pierre Péli-Gulli
- University of Fribourg, Department of Biology, Division of Biochemistry, Chemin du Musée 10, Fribourg CH-1700, Switzerland
| | - Henning Arlt
- University of Osnabrück, Department of Biology/Chemistry, Biochemistry section, Barbarastrasse 13, 49076 Osnabrück, Germany
| | - Alessandro Sardu
- University of Fribourg, Department of Biology, Division of Biochemistry, Chemin du Musée 10, Fribourg CH-1700, Switzerland
| | - Janice Griffith
- University Medical Centre Utrecht, Center for Molecular Medicine, Department of Cell Biology, Heidelberglaan 100, Utrecht 3584 CX, The Netherlands
| | - Tim Levine
- UCL Institute of Ophthalmology, Department of Cell Biology, 11-43 Bath St., London EC1V 9EL, UK
| | - Siegfried Engelbrecht-Vandré
- University of Osnabrück, Department of Biology/Chemistry, Biochemistry section, Barbarastrasse 13, 49076 Osnabrück, Germany
| | - Fulvio Reggiori
- University Medical Centre Utrecht, Center for Molecular Medicine, Department of Cell Biology, Heidelberglaan 100, Utrecht 3584 CX, The Netherlands
| | - Claudio De Virgilio
- University of Fribourg, Department of Biology, Division of Biochemistry, Chemin du Musée 10, Fribourg CH-1700, Switzerland
| | - Christian Ungermann
- University of Osnabrück, Department of Biology/Chemistry, Biochemistry section, Barbarastrasse 13, 49076 Osnabrück, Germany
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90
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Rana M, Lachmann J, Ungermann C. Identification of a Rab GTPase-activating protein cascade that controls recycling of the Rab5 GTPase Vps21 from the vacuole. Mol Biol Cell 2015; 26:2535-49. [PMID: 25971802 PMCID: PMC4571306 DOI: 10.1091/mbc.e15-02-0062] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Accepted: 05/06/2015] [Indexed: 01/30/2023] Open
Abstract
Endocytic transport depends on two consecutive Rabs, Vps21 (Rab5 in metazoans) and Ypt7 (Rab7), which bind to effectors on early and late endosomes. This study now shows that inactivation of Vps21 via its GTPase-activating protein (GAP) Msb3 requires both Ypt7 and fusion with the vacuole. The data suggest an endosomal GAP cascade that includes the effector of Ypt7. Transport within the endocytic pathway depends on a consecutive function of the endosomal Rab5 and the late endosomal/lysosomal Rab7 GTPases to promote membrane recycling and fusion in the context of endosomal maturation. We previously identified the hexameric BLOC-1 complex as an effector of the yeast Rab5 Vps21, which also recruits the GTPase-activating protein (GAP) Msb3. This raises the question of when Vps21 is inactivated on endosomes. We provide evidence for a Rab cascade in which activation of the Rab7 homologue Ypt7 triggers inactivation of Vps21. We find that the guanine nucleotide exchange factor (GEF) of Ypt7 (the Mon1-Ccz1 complex) and BLOC-1 both localize to the same endosomes. Overexpression of Mon1-Ccz1, which generates additional Ypt7-GTP, or overexpression of activated Ypt7 promotes relocalization of Vps21 from endosomes to the endoplasmic reticulum (ER), which is indicative of Vps21 inactivation. This ER relocalization is prevented by loss of either BLOC-1 or Msb3, but it also occurs in mutants lacking endosome–vacuole fusion machinery such as the HOPS tethering complex, an effector of Ypt7. Importantly, BLOC-1 interacts with the HOPS on vacuoles, suggesting a direct Ypt7-dependent cross-talk. These data indicate that efficient Vps21 recycling requires both Ypt7 and endosome–vacuole fusion, thus suggesting extended control of a GAP cascade beyond Rab interactions.
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Affiliation(s)
- Meenakshi Rana
- Biochemistry Section, Department of Biology/Chemistry, University of Osnabrück, 49076 Osnabrück, Germany
| | - Jens Lachmann
- Biochemistry Section, Department of Biology/Chemistry, University of Osnabrück, 49076 Osnabrück, Germany
| | - Christian Ungermann
- Biochemistry Section, Department of Biology/Chemistry, University of Osnabrück, 49076 Osnabrück, Germany
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91
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Bouchez I, Pouteaux M, Canonge M, Genet M, Chardot T, Guillot A, Froissard M. Regulation of lipid droplet dynamics in Saccharomyces cerevisiae depends on the Rab7-like Ypt7p, HOPS complex and V1-ATPase. Biol Open 2015; 4:764-75. [PMID: 25948753 PMCID: PMC4571102 DOI: 10.1242/bio.20148615] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
It has now been clearly shown that lipid droplets (LDs) play a dynamic role in the cell. This was reinforced by LD proteomics which suggest that a significant number of trafficking proteins are associated with this organelle. Using microscopy, we showed that LDs partly co-localize with the vacuole in S. cerevisiae. Immunoblot experiments confirmed the association of the vacuolar Rab GTPase Rab7-like Ypt7p with LDs. We observed an increase in fatty acid content and LD number in ypt7Δ mutant and also changes in LD morphology and intra LD fusions, revealing a direct role for Ypt7p in LD dynamics. Using co-immunoprecipitation, we isolated potential Ypt7p partners including, Vma13p, the H subunit of the V1 part of the vacuolar (H+) ATPase (V-ATPase). Deletion of the VMA13 gene, as well as deletion of three other subunits of the V1 part of the V-ATPase, also increased the cell fatty acid content and LD number. Mutants of the Homotypic fusion and vacuole protein sorting (HOPS) complex showed similar phenotypes. Here, we demonstrated that LD dynamics and membrane trafficking between the vacuole and LDs are regulated by the Rab7-like Ypt7p and are impaired when the HOPS complex and the V1 domain of the V-ATPase are defective.
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Affiliation(s)
- Isabelle Bouchez
- Institut Jean-Pierre Bourgin IJPB, UMR 1318 INRA, Saclay Plant Sciences, route de St Cyr (RD 10), 78026, Versailles cedex, France Institut Jean-Pierre Bourgin IJPB, UMR 1318 AgroParisTech, route de St Cyr (RD 10), 78026, Versailles cedex, France
| | - Marie Pouteaux
- Institut Jean-Pierre Bourgin IJPB, UMR 1318 INRA, Saclay Plant Sciences, route de St Cyr (RD 10), 78026, Versailles cedex, France Institut Jean-Pierre Bourgin IJPB, UMR 1318 AgroParisTech, route de St Cyr (RD 10), 78026, Versailles cedex, France
| | - Michel Canonge
- Institut Jean-Pierre Bourgin IJPB, UMR 1318 INRA, Saclay Plant Sciences, route de St Cyr (RD 10), 78026, Versailles cedex, France Institut Jean-Pierre Bourgin IJPB, UMR 1318 AgroParisTech, route de St Cyr (RD 10), 78026, Versailles cedex, France
| | - Mélanie Genet
- Institut Jean-Pierre Bourgin IJPB, UMR 1318 INRA, Saclay Plant Sciences, route de St Cyr (RD 10), 78026, Versailles cedex, France Institut Jean-Pierre Bourgin IJPB, UMR 1318 AgroParisTech, route de St Cyr (RD 10), 78026, Versailles cedex, France
| | - Thierry Chardot
- Institut Jean-Pierre Bourgin IJPB, UMR 1318 INRA, Saclay Plant Sciences, route de St Cyr (RD 10), 78026, Versailles cedex, France Institut Jean-Pierre Bourgin IJPB, UMR 1318 AgroParisTech, route de St Cyr (RD 10), 78026, Versailles cedex, France
| | - Alain Guillot
- MICALIS PAPPSO, UMR 1319 INRA, Domaine de Vilvert 78352, Jouy-en-Josas cedex, France MICALIS PAPPSO, UMR 1319 AgroParisTech, Domaine de Vilvert 78352, Jouy-en-Josas cedex, France
| | - Marine Froissard
- Institut Jean-Pierre Bourgin IJPB, UMR 1318 INRA, Saclay Plant Sciences, route de St Cyr (RD 10), 78026, Versailles cedex, France Institut Jean-Pierre Bourgin IJPB, UMR 1318 AgroParisTech, route de St Cyr (RD 10), 78026, Versailles cedex, France
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92
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Khatter D, Raina VB, Dwivedi D, Sindhwani A, Bahl S, Sharma M. The small GTPase Arl8b regulates assembly of the mammalian HOPS complex on lysosomes. J Cell Sci 2015; 128:1746-61. [PMID: 25908847 PMCID: PMC4432227 DOI: 10.1242/jcs.162651] [Citation(s) in RCA: 93] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Accepted: 03/18/2015] [Indexed: 01/17/2023] Open
Abstract
The homotypic fusion and protein sorting (HOPS) complex is a multi-subunit complex conserved from yeast to mammals that regulates late endosome and lysosome fusion. However, little is known about how the HOPS complex is recruited to lysosomes in mammalian cells. Here, we report that the small GTPase Arl8b, but not Rab7 (also known as RAB7A), is essential for membrane localization of the human (h)Vps41 subunit of the HOPS complex. Assembly of the core HOPS subunits to Arl8b- and hVps41-positive lysosomes is guided by their subunit-subunit interactions. RNA interference (RNAi)-mediated depletion of hVps41 resulted in the impaired degradation of EGFR that was rescued upon expression of wild-type but not an Arl8b-binding-defective mutant of hVps41, suggesting that Arl8b-dependent lysosomal localization of hVps41 is required for its endocytic function. Furthermore, we have also identified that the Arl8b effector SKIP (also known as PLEKHM2) interacts with and recruits HOPS subunits to Arl8b and kinesin-positive peripheral lysosomes. Accordingly, RNAi-mediated depletion of SKIP impaired lysosomal trafficking and degradation of EGFR. These findings reveal that Arl8b regulates the association of the human HOPS complex with lysosomal membranes, which is crucial for the function of this tethering complex in endocytic degradation.
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Affiliation(s)
- Divya Khatter
- Department of Biological Sciences, Indian Institute of Science Education and Research-Mohali (IISERM), India
| | - Vivek B Raina
- Department of Biological Sciences, Indian Institute of Science Education and Research-Mohali (IISERM), India
| | - Devashish Dwivedi
- Department of Biological Sciences, Indian Institute of Science Education and Research-Mohali (IISERM), India
| | - Aastha Sindhwani
- Department of Biological Sciences, Indian Institute of Science Education and Research-Mohali (IISERM), India
| | - Surbhi Bahl
- Department of Biological Sciences, Indian Institute of Science Education and Research-Mohali (IISERM), India
| | - Mahak Sharma
- Department of Biological Sciences, Indian Institute of Science Education and Research-Mohali (IISERM), India
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93
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Morlon‐Guyot J, Pastore S, Berry L, Lebrun M, Daher W. Toxoplasma gondii
Vps11, a subunit of
HOPS
and
CORVET
tethering complexes, is essential for the biogenesis of secretory organelles. Cell Microbiol 2015; 17:1157-78. [DOI: 10.1111/cmi.12426] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2014] [Revised: 01/20/2015] [Accepted: 01/28/2015] [Indexed: 12/17/2022]
Affiliation(s)
- Juliette Morlon‐Guyot
- Dynamique des Interactions Membranaires Normales et Pathologiques, UMR5235 CNRS Université Montpellier Montpellier France
| | - Sandra Pastore
- Dynamique des Interactions Membranaires Normales et Pathologiques, UMR5235 CNRS Université Montpellier Montpellier France
| | - Laurence Berry
- Dynamique des Interactions Membranaires Normales et Pathologiques, UMR5235 CNRS Université Montpellier Montpellier France
| | - Maryse Lebrun
- Dynamique des Interactions Membranaires Normales et Pathologiques, UMR5235 CNRS Université Montpellier Montpellier France
| | - Wassim Daher
- Dynamique des Interactions Membranaires Normales et Pathologiques, UMR5235 CNRS Université Montpellier Montpellier France
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94
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Stasi M, De Luca M, Bucci C. Two-hybrid-based systems: powerful tools for investigation of membrane traffic machineries. J Biotechnol 2014; 202:105-17. [PMID: 25529347 DOI: 10.1016/j.jbiotec.2014.12.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Revised: 12/05/2014] [Accepted: 12/11/2014] [Indexed: 01/18/2023]
Abstract
Protein-protein interactions regulate biological processes and are fundamental for cell functions. Recently, efforts have been made to define interactomes, which are maps of protein-protein interactions that are useful for understanding biological pathways and networks and for investigating how perturbations of these networks lead to diseases. Therefore, interactomes are becoming fundamental for establishing the molecular basis of human diseases and contributing to the discovery of effective therapies. Interactomes are constructed based on experimental data present in the literature and computational predictions of interactions. Several biochemical, genetic and biotechnological techniques have been used in the past to identify protein-protein interactions. The yeast two-hybrid system has beyond doubt represented a revolution in the field, being a versatile tool and allowing the immediate identification of the interacting proteins and isolation of the cDNA coding for the interacting peptide after in vivo screening. Recently, variants of the yeast two-hybrid assay have been developed, including high-throughput systems that promote the rapidly growing field of proteomics. In this review we will focus on the role of this technique in the discovery of Rab interacting proteins, highlighting the importance of high-throughput two-hybrid screening as a tool to study the complexity of membrane traffic machineries.
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Affiliation(s)
- Mariangela Stasi
- Department of Biological and Environmental Sciences and Technologies (DiSTeBA), University of Salento, Lecce, Italy
| | - Maria De Luca
- Department of Biological and Environmental Sciences and Technologies (DiSTeBA), University of Salento, Lecce, Italy
| | - Cecilia Bucci
- Department of Biological and Environmental Sciences and Technologies (DiSTeBA), University of Salento, Lecce, Italy.
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95
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McEwan DG, Popovic D, Gubas A, Terawaki S, Suzuki H, Stadel D, Coxon FP, Miranda de Stegmann D, Bhogaraju S, Maddi K, Kirchof A, Gatti E, Helfrich MH, Wakatsuki S, Behrends C, Pierre P, Dikic I. PLEKHM1 regulates autophagosome-lysosome fusion through HOPS complex and LC3/GABARAP proteins. Mol Cell 2014; 57:39-54. [PMID: 25498145 DOI: 10.1016/j.molcel.2014.11.006] [Citation(s) in RCA: 400] [Impact Index Per Article: 40.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Revised: 10/06/2014] [Accepted: 11/05/2014] [Indexed: 12/24/2022]
Abstract
The lysosome is the final destination for degradation of endocytic cargo, plasma membrane constituents, and intracellular components sequestered by macroautophagy. Fusion of endosomes and autophagosomes with the lysosome depends on the GTPase Rab7 and the homotypic fusion and protein sorting (HOPS) complex, but adaptor proteins that link endocytic and autophagy pathways with lysosomes are poorly characterized. Herein, we show that Pleckstrin homology domain containing protein family member 1 (PLEKHM1) directly interacts with HOPS complex and contains a LC3-interacting region (LIR) that mediates its binding to autophagosomal membranes. Depletion of PLEKHM1 blocks lysosomal degradation of endocytic (EGFR) cargo and enhances presentation of MHC class I molecules. Moreover, genetic loss of PLEKHM1 impedes autophagy flux upon mTOR inhibition and PLEKHM1 regulates clearance of protein aggregates in an autophagy- and LIR-dependent manner. PLEKHM1 is thus a multivalent endocytic adaptor involved in the lysosome fusion events controlling selective and nonselective autophagy pathways.
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Affiliation(s)
- David G McEwan
- Institute of Biochemistry II, Goethe University School of Medicine, Theodor-Stern-Kai 7, D-60590 Frankfurt (Main), Germany
| | - Doris Popovic
- Institute of Biochemistry II, Goethe University School of Medicine, Theodor-Stern-Kai 7, D-60590 Frankfurt (Main), Germany
| | - Andrea Gubas
- Institute of Biochemistry II, Goethe University School of Medicine, Theodor-Stern-Kai 7, D-60590 Frankfurt (Main), Germany
| | - Seigo Terawaki
- Centre d'Immunologie de Marseille-Luminy, Aix-Marseille Université, UM2, 13288 Marseille, France; INSERM, U1104, 13288 Marseille, France; CNRS, UMR 7280, 13288 Marseille, France
| | - Hironori Suzuki
- Biomolecular Interaction Centre, School of Biological Sciences, University of Canterbury, Christchurch 8020, New Zealand
| | - Daniela Stadel
- Institute of Biochemistry II, Goethe University School of Medicine, Theodor-Stern-Kai 7, D-60590 Frankfurt (Main), Germany
| | - Fraser P Coxon
- Musculoskeletal Research Programme, Division of Applied Medicine, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, UK
| | - Diana Miranda de Stegmann
- Musculoskeletal Research Programme, Division of Applied Medicine, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, UK
| | - Sagar Bhogaraju
- Buchmann Institute for Molecular Life Sciences, Max-von-Laue-Str. 15, Goethe University 60438 Frankfurt am Main, Germany
| | - Karthik Maddi
- Buchmann Institute for Molecular Life Sciences, Max-von-Laue-Str. 15, Goethe University 60438 Frankfurt am Main, Germany
| | - Anja Kirchof
- Institute of Biochemistry II, Goethe University School of Medicine, Theodor-Stern-Kai 7, D-60590 Frankfurt (Main), Germany
| | - Evelina Gatti
- Centre d'Immunologie de Marseille-Luminy, Aix-Marseille Université, UM2, 13288 Marseille, France; INSERM, U1104, 13288 Marseille, France; CNRS, UMR 7280, 13288 Marseille, France
| | - Miep H Helfrich
- Musculoskeletal Research Programme, Division of Applied Medicine, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, UK
| | - Soichi Wakatsuki
- Structural Biology Research Center, Photon Factory, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
| | - Christian Behrends
- Institute of Biochemistry II, Goethe University School of Medicine, Theodor-Stern-Kai 7, D-60590 Frankfurt (Main), Germany
| | - Philippe Pierre
- Centre d'Immunologie de Marseille-Luminy, Aix-Marseille Université, UM2, 13288 Marseille, France; INSERM, U1104, 13288 Marseille, France; CNRS, UMR 7280, 13288 Marseille, France
| | - Ivan Dikic
- Institute of Biochemistry II, Goethe University School of Medicine, Theodor-Stern-Kai 7, D-60590 Frankfurt (Main), Germany; Buchmann Institute for Molecular Life Sciences, Max-von-Laue-Str. 15, Goethe University 60438 Frankfurt am Main, Germany; University of Split, School of Medicine, Department of Immunology and Medical Genetics, Soltanska 2, 21 000 Split, Croatia.
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96
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RILP interacts with HOPS complex via VPS41 subunit to regulate endocytic trafficking. Sci Rep 2014; 4:7282. [PMID: 25445562 PMCID: PMC4250914 DOI: 10.1038/srep07282] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Accepted: 11/13/2014] [Indexed: 11/30/2022] Open
Abstract
The HOPS complex serves as a tethering complex with GEF activity for Ypt7p in yeast to regulate late endosomal membrane maturation. While the role of HOPS complex is well established in yeast cells, its functional and mechanistic aspects in mammalian cells are less well defined. In this study, we report that RILP, a downstream effector of Rab7, interacts with HOPS complex and recruits HOPS subunits to the late endosomal compartment. Structurally, the amino-terminal portion of RILP interacts with HOPS complex. Unexpectedly, this interaction is independent of Rab7. VPS41 subunit of HOPS complex was defined to be the major partner for interacting with RILP. The carboxyl-terminal region of VPS41 was mapped to be responsible for the interaction. Functionally, either depletion of VPS41 by shRNA or overexpression of VPS41 C-terminal half retarded EGF-induced degradation of EGFR. These results suggest that interaction of RILP with HOPS complex via VPS41 plays a role in endocytic trafficking of EGFR.
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97
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Lachmann J, Ungermann C, Engelbrecht-Vandré S. Rab GTPases and tethering in the yeast endocytic pathway. Small GTPases 2014; 2:182-186. [PMID: 21776422 DOI: 10.4161/sgtp.2.3.16701] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2011] [Revised: 05/24/2011] [Accepted: 05/30/2011] [Indexed: 11/19/2022] Open
Abstract
Within eukaryotic cells, Rab GTPases control the maturation of early to late endosomes and their subsequent fusion with the vacuole. Within this ExtraView, we will focus on our recent findings regarding the activation of the Rab7 homolog Ypt7 in yeast and its interplay with the two multisubunit tethering complexes CORVET and HOPS.
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Affiliation(s)
- Jens Lachmann
- Department of Biology/Chemistry; Biochemistry Section; University of Osnabrück; Osnabrück, Germany
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98
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Zlatic SA, Tornieri K, L'hernault SW, Faundez V. Metazoan cell biology of the HOPS tethering complex. CELLULAR LOGISTICS 2014; 1:111-117. [PMID: 21922076 DOI: 10.4161/cl.1.3.17279] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2011] [Revised: 07/18/2011] [Accepted: 07/20/2011] [Indexed: 01/09/2023]
Abstract
Membrane fusion with vacuoles, the lysosome equivalent of the yeast Saccharomyces cerevisiae, is among the best understood membrane fusion events. Our precise understanding of this fusion machinery stems from powerful genetics and elegant in vitro reconstitution assays. Central to vacuolar membrane fusion is the multi-subunit tether the HO motypic fusion and Protein Sorting (HOPS) complex, a complex of proteins that organizes other necessary components of the fusion machinery. We lack a similarly detailed molecular understanding of membrane fusion with lysosomes or lysosome-related organelles in metazoans. However, it is likely that fundamental principles of how rabs, SNAREs and HOPS tethers work to fuse membranes with lysosomes and related organelles are conserved between Saccharomyces cerevisiae and metazoans. Here, we discuss emerging differences in the coat-dependent mechanisms that govern HOPS complex subcellular distribution between Saccharomyces cerevisiae and metazoans. These differences reside upstream of the membrane fusion event. We propose that the differences in how coats segregate class C Vps/HOPS tethers to organelles and domains of metazoan cells are adaptations to complex architectures that characterize metazoan cells such as those of neuronal and epithelial tissues.
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Affiliation(s)
- Stephanie A Zlatic
- Graduate Program in Biochemistry, Cell and Developmental Biology; Emory University; Atlanta, GA USA
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99
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Lachmann J, Glaubke E, Moore PS, Ungermann C. The Vps39-like TRAP1 is an effector of Rab5 and likely the missing Vps3 subunit of human CORVET. CELLULAR LOGISTICS 2014; 4:e970840. [PMID: 25750764 DOI: 10.4161/21592780.2014.970840] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Accepted: 09/25/2014] [Indexed: 12/22/2022]
Abstract
Membrane fusion in the endocytic pathway is mediated by a protein machinery consistent of Rab GTPases, tethering factors and SNAREs. In yeast, the endosomal CORVET and lysosomal HOPS tethering complexes share 4 of their 6 subunits. The 2 additional subunits in each complex - Vps3 and Vps8 for CORVET, and the homologous Vps39 and Vps41 for HOPS - bind directly to Rab5 and Rab7, respectively. In humans, all subunits for HOPS have been described. However, human CORVET remains poorly characterized and a homolog of Vps3 is still missing. Here we characterize 2 previously identified Vps39 isoforms, hVps39-1/hVam6/TLP and hVps39-2/TRAP1, in yeast and HEK293 cells. None of them can compensate the loss of the endogenous yeast Vps39, though the specific interaction of hVps39-1 with the virus-specific LT protein was reproduced. Both human Vps39 proteins show a cytosolic localization in yeast and mammalian cells. However, hVps39-2/TRAP1 strongly co-localizes with co-expressed Rab5 and interacts directly with Rab5-GTP in vitro. We conclude that hVps39-2/TRAP1 is an endosomal protein and an effector of Rab5, suggesting a role of the protein as a subunit of the putative human CORVET complex.
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Affiliation(s)
- Jens Lachmann
- Department of Biology/Chemistry; Biochemistry Section; University of Osnabruck ; Osnabrück, Germany
| | - Elina Glaubke
- Department of Biology/Chemistry; Biochemistry Section; University of Osnabruck ; Osnabrück, Germany
| | - Patrick S Moore
- University of Pittsburgh Cancer Institute; Cancer Virology Program ; Pittsburgh, PA USA
| | - Christian Ungermann
- Department of Biology/Chemistry; Biochemistry Section; University of Osnabruck ; Osnabrück, Germany
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100
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Zick M, Wickner WT. A distinct tethering step is vital for vacuole membrane fusion. eLife 2014; 3:e03251. [PMID: 25255215 PMCID: PMC4200421 DOI: 10.7554/elife.03251] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2014] [Accepted: 09/24/2014] [Indexed: 12/12/2022] Open
Abstract
Past experiments with reconstituted proteoliposomes, employing assays that infer membrane fusion from fluorescent lipid dequenching, have suggested that vacuolar SNAREs alone suffice to catalyze membrane fusion in vitro. While we could replicate these results, we detected very little fusion with the more rigorous assay of lumenal compartment mixing. Exploring the discrepancies between lipid-dequenching and content-mixing assays, we surprisingly found that the disposition of the fluorescent lipids with respect to SNAREs had a striking effect. Without other proteins, the association of SNAREs in trans causes lipid dequenching that cannot be ascribed to fusion or hemifusion. Tethering of the SNARE-bearing proteoliposomes was required for efficient lumenal compartment mixing. While the physiological HOPS tethering complex caused a few-fold increase of trans-SNARE association, the rate of content mixing increased more than 100-fold. Thus tethering has a role in promoting membrane fusion that extends beyond simply increasing the amount of total trans-SNARE complex. DOI:http://dx.doi.org/10.7554/eLife.03251.001 Cells of higher organisms contain compartments called organelles and structures called vesicles that transfer molecules and proteins between these organelles. Each organelle and each vesicle is enclosed within a membrane, and these membranes must fuse together to allow these transfers to take place. A certain group of proteins, called SNAREs, have a central role in these fusion events. Since membrane fusion is difficult to observe directly, many researchers have used a method called ‘fluorescent lipid dequenching’ to study it indirectly. In this approach, one fraction of vesicles is labeled with two fluorescent molecules, with one of these molecules quenching the fluorescence of the other. However, when a labeled vesicle fuses with an unlabeled vesicle, the surface concentrations of the fluorescent molecules are diluted. This reduces the amount of quenching and the resulting increase in fluorescence can be measured. Experiments utilizing this technique had suggested that SNARE proteins are sufficient for fusion to take place, and that no other protein complexes need to be present. However, when a different assay method called ‘lumenal compartment mixing’ was used, little fusion was seen when the only proteins present were the SNAREs. The lumenal compartment mixing approach relies on measuring the degree of mixing between the contents of two vesicles. To address these conflicting results, Zick and Wickner used both methods to study fusion in a yeast-based system. The lumenal compartment mixing approach, which is the more reliable method, revealed that rapid and efficient membrane fusion in fact requires another protein complex, called HOPS, to hold the two membrane vesicles together. Zick and Wickner found that the HOPS complex does not enable fusion by just increasing the amount of interactions between the SNARE proteins. Rather, it seems to facilitate the formation of a particular quality of SNARE interactions. Future work is needed to work out how the SNARE complexes become ‘fusion-competent’, and to explore the mechanism that allows the HOPS complex to assist in the formation of fusion-competent SNARE complexes. DOI:http://dx.doi.org/10.7554/eLife.03251.002
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Affiliation(s)
- Michael Zick
- Department of Biochemistry, Geisel School of Medicine at Dartmouth, Hanover, United States
| | - William T Wickner
- Department of Biochemistry, Geisel School of Medicine at Dartmouth, Hanover, United States
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