1
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Wisner SR, Chlebowski M, Mandal A, Mai D, Stein C, Petralia RS, Wang YX, Drerup CM. An initial HOPS-mediated fusion event is critical for autophagosome transport initiation from the axon terminal. Autophagy 2024; 20:2275-2296. [PMID: 38899385 DOI: 10.1080/15548627.2024.2366122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2023] [Revised: 05/22/2024] [Accepted: 06/05/2024] [Indexed: 06/21/2024] Open
Abstract
In neurons, macroautophagy/autophagy is a frequent and critical process. In the axon, autophagy begins in the axon terminal, where most nascent autophagosomes form. After formation, autophagosomes must initiate transport to exit the axon terminal and move toward the cell body via retrograde transport. During retrograde transport these autophagosomes mature through repetitive fusion events. Complete lysosomal cargo degradation occurs largely in the cell body. The precipitating events to stimulate retrograde autophagosome transport have been debated but their importance is clear: disrupting neuronal autophagy or autophagosome transport is detrimental to neuronal health and function. We have identified the HOPS complex as essential for early autophagosome maturation and consequent initiation of retrograde transport from the axon terminal. In yeast and mammalian cells, HOPS controls fusion between autophagosomes and late endosomes with lysosomes. Using zebrafish strains with loss-of-function mutations in vps18 and vps41, core components of the HOPS complex, we found that disruption of HOPS eliminates autophagosome maturation and disrupts retrograde autophagosome transport initiation from the axon terminal. We confirmed this phenotype was due to loss of HOPS complex formation using an endogenous deletion of the HOPS binding domain in Vps18. Finally, using pharmacological inhibition of lysosomal proteases, we show that initiation of autophagosome retrograde transport requires autophagosome maturation. Together, our data demonstrate that HOPS-mediated fusion events are critical for retrograde autophagosome transport initiation through promoting autophagosome maturation. This reveals critical roles for the HOPS complex in neuronal autophagy which deepens our understanding of the cellular pathology of HOPS-complex linked neurodegenerative diseases.Abbreviations: CORVET: Class C core vacuole/endosome tethering; gRNA: guide RNA; HOPS: homotypic fusion and protein sorting; pLL: posterior lateral line; Vps18: VPS18 core subunit of CORVET and HOPS complexes; Vps41: VPS41 subunit of HOPS complex.
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Affiliation(s)
- Serena R Wisner
- Department of Integrative Biology, University of Wisconsin-Madison, Madison, WI, USA
- Neuroscience Training Program, University of Wisconsin-Madison, Madison, WI, USA
| | - Madison Chlebowski
- Department of Integrative Biology, University of Wisconsin-Madison, Madison, WI, USA
| | - Amrita Mandal
- National Institute of Child Health and Human Development, NIH, Bethesda, MD, USA
| | - Don Mai
- Department of Integrative Biology, University of Wisconsin-Madison, Madison, WI, USA
| | - Chris Stein
- Department of Integrative Biology, University of Wisconsin-Madison, Madison, WI, USA
| | - Ronald S Petralia
- Advanced Imaging Core, National Institute of Deafness and Other Communication Disorders, NIH, Bethesda, MD, USA
| | - Ya-Xian Wang
- Advanced Imaging Core, National Institute of Deafness and Other Communication Disorders, NIH, Bethesda, MD, USA
| | - Catherine M Drerup
- Department of Integrative Biology, University of Wisconsin-Madison, Madison, WI, USA
- Neuroscience Training Program, University of Wisconsin-Madison, Madison, WI, USA
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2
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Duan M, Gao G, Lin A, Mackey EJ, Banfield DK, Merz AJ. SM protein Sly1 and a SNARE Habc domain promote membrane fusion through multiple mechanisms. J Cell Biol 2024; 223:e202001034. [PMID: 38478017 PMCID: PMC10943372 DOI: 10.1083/jcb.202001034] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 12/20/2023] [Accepted: 02/22/2024] [Indexed: 03/17/2024] Open
Abstract
SM proteins including Sly1 are essential cofactors of SNARE-mediated membrane fusion. Using SNARE and Sly1 mutants and chemically defined in vitro assays, we separate and assess proposed mechanisms through which Sly1 augments fusion: (i) opening the closed conformation of the Qa-SNARE Sed5; (ii) close-range tethering of vesicles to target organelles, mediated by the Sly1-specific regulatory loop; and (iii) nucleation of productive trans-SNARE complexes. We show that all three mechanisms are important and operate in parallel, and that close-range tethering promotes trans-complex assembly when cis-SNARE assembly is a competing process. Further, we demonstrate that the autoinhibitory N-terminal Habc domain of Sed5 has at least two positive activities: it is needed for correct Sed5 localization, and it directly promotes Sly1-dependent fusion. "Split Sed5," with Habc presented solely as a soluble fragment, can function both in vitro and in vivo. Habc appears to facilitate events leading to lipid mixing rather than promoting opening or stability of the fusion pore.
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Affiliation(s)
- Mengtong Duan
- Department of Biochemistry, University of Washington, Seattle, WA, USA
| | - Guanbin Gao
- The Division of Life Science, The Hong Kong University of Science and Technology, Kowloon, Hong Kong
| | - Ariel Lin
- Department of Biochemistry, University of Washington, Seattle, WA, USA
| | - Emma J. Mackey
- Department of Biochemistry, University of Washington, Seattle, WA, USA
| | - David K. Banfield
- The Division of Life Science, The Hong Kong University of Science and Technology, Kowloon, Hong Kong
| | - Alexey J. Merz
- Department of Biochemistry, University of Washington, Seattle, WA, USA
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3
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Duan M, Plemel RL, Takenaka T, Lin A, Delgado BM, Nattermann U, Nickerson DP, Mima J, Miller EA, Merz AJ. SNARE chaperone Sly1 directly mediates close-range vesicle tethering. J Cell Biol 2024; 223:e202001032. [PMID: 38478018 PMCID: PMC10943277 DOI: 10.1083/jcb.202001032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 12/20/2023] [Accepted: 02/22/2024] [Indexed: 03/17/2024] Open
Abstract
The essential Golgi protein Sly1 is a member of the Sec1/mammalian Unc-18 (SM) family of SNARE chaperones. Sly1 was originally identified through remarkable gain-of-function alleles that bypass requirements for diverse vesicle tethering factors. Employing genetic analyses and chemically defined reconstitutions of ER-Golgi fusion, we discovered that a loop conserved among Sly1 family members is not only autoinhibitory but also acts as a positive effector. An amphipathic lipid packing sensor (ALPS)-like helix within the loop directly binds high-curvature membranes. Membrane binding is required for relief of Sly1 autoinhibition and also allows Sly1 to directly tether incoming vesicles to the Qa-SNARE on the target organelle. The SLY1-20 mutation bypasses requirements for diverse tethering factors but loses this ability if the tethering activity is impaired. We propose that long-range tethers, including Golgins and multisubunit tethering complexes, hand off vesicles to Sly1, which then tethers at close range to initiate trans-SNARE complex assembly and fusion in the early secretory pathway.
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Affiliation(s)
- Mengtong Duan
- Department of Biochemistry, University of Washington, Seattle, WA, USA
| | - Rachael L. Plemel
- Department of Biochemistry, University of Washington, Seattle, WA, USA
| | | | - Ariel Lin
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Department of Biology, California State University, San Bernardino, CA, USA
| | | | - Una Nattermann
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Biophysics, Structure, and Design Graduate Program, University of Washington, Seattle, WA, USA
- Institute for Protein Design, University of Washington, Seattle, WA, USA
| | | | - Joji Mima
- Institute for Protein Research, Osaka University, Osaka, Japan
| | | | - Alexey J. Merz
- Department of Biochemistry, University of Washington, Seattle, WA, USA
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4
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van der Beek J, de Heus C, Sanza P, Liv N, Klumperman J. Loss of the HOPS complex disrupts early-to-late endosome transition, impairs endosomal recycling and induces accumulation of amphisomes. Mol Biol Cell 2024; 35:ar40. [PMID: 38198575 PMCID: PMC10916860 DOI: 10.1091/mbc.e23-08-0328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 12/22/2023] [Accepted: 01/05/2024] [Indexed: 01/12/2024] Open
Abstract
The multisubunit HOPS tethering complex is a well-established regulator of lysosome fusion with late endosomes and autophagosomes. However, the role of the HOPS complex in other stages of endo-lysosomal trafficking is not well understood. To address this, we made HeLa cells knocked out for the HOPS-specific subunits Vps39 or Vps41, or the HOPS-CORVET-core subunits Vps18 or Vps11. In all four knockout cells, we found that endocytosed cargos were trapped in enlarged endosomes that clustered in the perinuclear area. By correlative light-electron microscopy, these endosomes showed a complex ultrastructure and hybrid molecular composition, displaying markers for early (Rab5, PtdIns3P, EEA1) as well as late (Rab7, CD63, LAMP1) endosomes. These "HOPS bodies" were not acidified, contained enzymatically inactive cathepsins and accumulated endocytosed cargo and cation-independent mannose-6-phosphate receptor (CI-MPR). Consequently, CI-MPR was depleted from the TGN, and secretion of lysosomal enzymes to the extracellular space was enhanced. Strikingly, HOPS bodies also contained the autophagy proteins p62 and LC3, defining them as amphisomes. Together, these findings show that depletion of the lysosomal HOPS complex has a profound impact on the functional organization of the entire endosomal system and suggest the existence of a HOPS-independent mechanism for amphisome formation.
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Affiliation(s)
- Jan van der Beek
- Center for Molecular Medicine, University Medical Center Utrecht, Institute of Biomembranes, Utrecht University, 3584 CX Utrecht, The Netherlands
| | - Cecilia de Heus
- Center for Molecular Medicine, University Medical Center Utrecht, Institute of Biomembranes, Utrecht University, 3584 CX Utrecht, The Netherlands
| | - Paolo Sanza
- Center for Molecular Medicine, University Medical Center Utrecht, Institute of Biomembranes, Utrecht University, 3584 CX Utrecht, The Netherlands
| | - Nalan Liv
- Center for Molecular Medicine, University Medical Center Utrecht, Institute of Biomembranes, Utrecht University, 3584 CX Utrecht, The Netherlands
| | - Judith Klumperman
- Center for Molecular Medicine, University Medical Center Utrecht, Institute of Biomembranes, Utrecht University, 3584 CX Utrecht, The Netherlands
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5
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Zhang S, Tong M, Zheng D, Huang H, Li L, Ungermann C, Pan Y, Luo H, Lei M, Tang Z, Fu W, Chen S, Liu X, Zhong Q. C9orf72-catalyzed GTP loading of Rab39A enables HOPS-mediated membrane tethering and fusion in mammalian autophagy. Nat Commun 2023; 14:6360. [PMID: 37821429 PMCID: PMC10567733 DOI: 10.1038/s41467-023-42003-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Accepted: 09/25/2023] [Indexed: 10/13/2023] Open
Abstract
The multi-subunit homotypic fusion and vacuole protein sorting (HOPS) membrane-tethering complex is required for autophagosome-lysosome fusion in mammals, yet reconstituting the mammalian HOPS complex remains a challenge. Here we propose a "hook-up" model for mammalian HOPS complex assembly, which requires two HOPS sub-complexes docking on membranes via membrane-associated Rabs. We identify Rab39A as a key small GTPase that recruits HOPS onto autophagic vesicles. Proper pairing with Rab2 and Rab39A enables HOPS complex assembly between proteoliposomes for its tethering function, facilitating efficient membrane fusion. GTP loading of Rab39A is important for the recruitment of HOPS to autophagic membranes. Activation of Rab39A is catalyzed by C9orf72, a guanine exchange factor associated with amyotrophic lateral sclerosis and familial frontotemporal dementia. Constitutive activation of Rab39A can rescue autophagy defects caused by C9orf72 depletion. These results therefore reveal a crucial role for the C9orf72-Rab39A-HOPS axis in autophagosome-lysosome fusion.
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Affiliation(s)
- Shen Zhang
- Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Department of Pathophysiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Mindan Tong
- Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Department of Pathophysiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Denghao Zheng
- Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Department of Pathophysiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Huiying Huang
- Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Department of Pathophysiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Linsen Li
- Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Department of Pathophysiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Christian Ungermann
- Osnabrück University, Department of Biology/Chemistry, Biochemistry section, Osnabrück, Germany
- Center of Cellular Nanoanalytic Osnabrück (CellNanOs), Osnabrück University, Osnabrück, Germany
| | - Yi Pan
- Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Department of Pathophysiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Hanyan Luo
- Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Department of Pathophysiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Ming Lei
- State Key Laboratory of Oncogenes and Related Genes, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, 200011, Shanghai, China
- Shanghai Institute of Precision Medicine, 200125, Shanghai, China
| | - Zaiming Tang
- Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Department of Pathophysiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Wan Fu
- Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Department of Pathophysiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - She Chen
- National Institute of Biological Sciences, 102206, Beijing, China
| | - Xiaoxia Liu
- Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Department of Pathophysiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
| | - Qing Zhong
- Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Department of Pathophysiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
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6
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Wang T, Yan L, Wang L, Sun J, Qu H, Ma Y, Song R, Tong X, Zhu J, Yuan Y, Gu J, Bian J, Liu Z, Zou H. VPS41-mediated incomplete autophagy aggravates cadmium-induced apoptosis in mouse hepatocytes. JOURNAL OF HAZARDOUS MATERIALS 2023; 459:132243. [PMID: 37562348 DOI: 10.1016/j.jhazmat.2023.132243] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 08/04/2023] [Accepted: 08/05/2023] [Indexed: 08/12/2023]
Abstract
Exposure to cadmium (Cd), an environmental heavy metal contaminant, is a serious threat to global health that increases the burden of liver diseases. Autophagy and apoptosis are important in Cd-induced liver injury. However, the regulatory mechanisms involved in the progression of Cd-induced liver damage are poorly understood. Herein, we investigated the role of vacuolar protein sorting 41 (VPS41) in Cd-induced autophagy and apoptosis in hepatocytes. We used targeted VPS41 regulation to elucidate the mechanism of Cd-induced hepatotoxicity. Our data showed that Cd triggered incomplete autophagy by downregulating VPS41, aggravating Cd-induced hepatocyte apoptosis. Mechanistically, Cd-induced VPS41 downregulation interfered with the mTORC1-TFEB/TFE3 axis, leading to an imbalance in autophagy initiation and termination and abnormal activation of autophagy. Moreover, Cd-induced downregulation of VPS41 inhibited autophagosome-lysosome fusion, leading to blocked autophagic flux. This triggers incomplete autophagy, which causes excessive P62 accumulation, accelerating Caspase-9 (CASP9) cleavage. Incomplete autophagy blocks clearance of cleaved CASP9 (CL-CASP9) via the autophagic pathway, promoting apoptosis. Notably, VPS41 overexpression alleviated Cd-induced incomplete autophagy and apoptosis, independent of the homotypic fusion and protein sorting complex. This study provides a new mechanistic understanding of the relationship between autophagy and apoptosis, suggesting that VPS41 is a new therapeutic target for Cd-induced liver damage.
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Affiliation(s)
- Tao Wang
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, Jiangsu, China; Joint International Research Laboratory of Agriculture and Agri-Product Safety of the Ministry of Education of China, Yangzhou University, Yangzhou 225009, Jiangsu, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, Jiangsu, China
| | - Lianqi Yan
- Department of Orthopedics, The Second Xiangya Hospital of Central South University, Changsha 410000, Hunan, China; Department of Orthopedics, Clinical Medical College of Yangzhou University, Subei People's Hospital, Yangzhou 225009, Jiangsu, China
| | - Li Wang
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, Jiangsu, China; Joint International Research Laboratory of Agriculture and Agri-Product Safety of the Ministry of Education of China, Yangzhou University, Yangzhou 225009, Jiangsu, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, Jiangsu, China
| | - Jian Sun
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, Jiangsu, China; Joint International Research Laboratory of Agriculture and Agri-Product Safety of the Ministry of Education of China, Yangzhou University, Yangzhou 225009, Jiangsu, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, Jiangsu, China
| | - Huayi Qu
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, Jiangsu, China; Joint International Research Laboratory of Agriculture and Agri-Product Safety of the Ministry of Education of China, Yangzhou University, Yangzhou 225009, Jiangsu, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, Jiangsu, China
| | - Yonggang Ma
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, Jiangsu, China; Joint International Research Laboratory of Agriculture and Agri-Product Safety of the Ministry of Education of China, Yangzhou University, Yangzhou 225009, Jiangsu, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, Jiangsu, China
| | - Ruilong Song
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, Jiangsu, China; Joint International Research Laboratory of Agriculture and Agri-Product Safety of the Ministry of Education of China, Yangzhou University, Yangzhou 225009, Jiangsu, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, Jiangsu, China
| | - Xishuai Tong
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, Jiangsu, China; Joint International Research Laboratory of Agriculture and Agri-Product Safety of the Ministry of Education of China, Yangzhou University, Yangzhou 225009, Jiangsu, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, Jiangsu, China; Jiangsu Key Laboratory of Zoonosis, Yangzhou 225009, Jiangsu, China
| | - Jiaqiao Zhu
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, Jiangsu, China; Joint International Research Laboratory of Agriculture and Agri-Product Safety of the Ministry of Education of China, Yangzhou University, Yangzhou 225009, Jiangsu, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, Jiangsu, China
| | - Yan Yuan
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, Jiangsu, China; Joint International Research Laboratory of Agriculture and Agri-Product Safety of the Ministry of Education of China, Yangzhou University, Yangzhou 225009, Jiangsu, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, Jiangsu, China
| | - Jianhong Gu
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, Jiangsu, China; Joint International Research Laboratory of Agriculture and Agri-Product Safety of the Ministry of Education of China, Yangzhou University, Yangzhou 225009, Jiangsu, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, Jiangsu, China
| | - Jianchun Bian
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, Jiangsu, China; Joint International Research Laboratory of Agriculture and Agri-Product Safety of the Ministry of Education of China, Yangzhou University, Yangzhou 225009, Jiangsu, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, Jiangsu, China
| | - Zongping Liu
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, Jiangsu, China; Joint International Research Laboratory of Agriculture and Agri-Product Safety of the Ministry of Education of China, Yangzhou University, Yangzhou 225009, Jiangsu, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, Jiangsu, China
| | - Hui Zou
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, Jiangsu, China; Joint International Research Laboratory of Agriculture and Agri-Product Safety of the Ministry of Education of China, Yangzhou University, Yangzhou 225009, Jiangsu, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, Jiangsu, China.
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7
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Jani C, Marsh A, Uchil P, Jain N, Baskir ZR, Glover OT, Root DE, Doench JG, Barczak AK. Vps18 contributes to phagosome membrane integrity in Mycobacterium tuberculosis-infected macrophages. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.01.560397. [PMID: 37873319 PMCID: PMC10592876 DOI: 10.1101/2023.10.01.560397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
Mycobacterium tuberculosis (Mtb) has evolved to be exquisitely adapted to survive within host macrophages. The capacity to damage the phagosomal membrane has emerged as central to Mtb virulence. While Mtb factors driving membrane damage have been described, host factors that repair that damage to contain the pathogen remain largely unknown. We used a genome-wide CRISPR screen to identify novel host factors required to repair Mtb-damaged phagosomal membranes. Vacuolar protein sorting-associated protein 18 (Vps18), a member of the HOPS and CORVET trafficking complexes, was among the top hits. Vps18 colocalized with Mtb in macrophages beginning shortly after infection, and Vps18-knockout macrophages demonstrated increased damage of Mtb-containing phagosomes without impaired autophagy. Mtb grew more robustly in Vps18-knockout cells, and the first-line anti-tuberculosis antibiotic pyrazinamide was less effective. Our results identify Vps18 as required for phagosomal membrane integrity in Mtb-infected cells and suggest that modulating phagosome integrity may hold promise for improving the efficacy of antibiotic treatment for TB.
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Affiliation(s)
| | | | - Pooja Uchil
- The Ragon Institute of MGH, MIT and Harvard
- Institute of Clinical and Molecular Virology, Friedrich-Alexander Universität Erlangen-Nürnberg
| | - Neha Jain
- The Ragon Institute of MGH, MIT and Harvard
| | | | | | | | | | - Amy K Barczak
- The Ragon Institute of MGH, MIT and Harvard
- The Broad Institute
- Division of Infectious Diseases, Massachusetts General Hospital
- Department of Medicine, Harvard Medical School
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8
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Huang H, Ouyang Q, Mei K, Liu T, Sun Q, Liu W, Liu R. Acetylation of SCFD1 regulates SNARE complex formation and autophagosome-lysosome fusion. Autophagy 2023; 19:189-203. [PMID: 35465820 PMCID: PMC9809933 DOI: 10.1080/15548627.2022.2064624] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
SCFD1 (sec1 family domain containing 1) was recently shown to function in autophagosome-lysosome fusion, and multiple studies have demonstrated the regulatory impacts of acetylation (a post-translational modification) on macroautophagy/autophagy. Here, we demonstrate that both acetylation- and phosphorylation-dependent mechanisms control SCFD1's function in autophagosome-lysosome fusion. After detecting a decrease in the extent of SCFD1 acetylation under autophagy-stimulated conditions, we found that KAT2B/PCAF catalyzes the acetylation of residues K126 and K515 of SCFD1; we also showed that these two residues are deacetylated by SIRT4. Importantly, we showed that AMPK-controlled SCFD1 phosphorylation strongly disrupts the capacity of SCFD1 to interact with KAT2B, thus ensuring that the SCFD1 acetylation level remains low. Finally, we demonstrated that SCFD1 acetylation inhibits autophagic flux, specifically by blocking STX17-SNAP29-VAMP8 SNARE complex formation. Thus, our study reveals a mechanism through which phosphorylation and acetylation modifications of SCFD1 mediate SNARE complex formation to regulate autophagosome maturation.ACLY: ATP citrate lyase; CREB: cAMP responsive element binding protein; EBSS: nutrient-deprivation medium; EP300: E1A binding protein p300; KAT5/TIP60: lysine acetyltransferase 5; HOPS: homotypic fusion and protein sorting; MS: mass spectroscopy; SCFD1: sec1 family domain containing 1; SM: Sec1/Munc18; SNARE: soluble N-ethylmaleimide-sensitive factor attachment protein receptor; UVRAG: UV radiation resistance associated.
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Affiliation(s)
- Hong Huang
- College of Food Science and Technology, School of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Qinqin Ouyang
- College of Food Science and Technology, School of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Kunrong Mei
- School of Pharmaceutical Science and Technology, Tianjin University, Tianjing, Tianjing, China
| | - Ting Liu
- Department of Cell Biology, and Department of General Surgery of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Qiming Sun
- Department of Biochemistry, and Department of Cardiology of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Wei Liu
- Department of Biochemistry, and Department of Cardiology of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China,Zhejiang University School of Medicine, Joint Institute of Genetics and Genomics Medicine between Zhejiang University and University of Toronto, Hangzhou, Zhejiang, China
| | - Rong Liu
- College of Food Science and Technology, School of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, China,Zhejiang University School of Medicine, Lead Contact, Nanjing, China,CONTACT Rong Liu College of Food Science and Technology, School of Life Sciences, Nanjing Agricultural University, Nanjing210095, China
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9
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Garg M, Roy D, Rajyaguru PI. Low complexity RGG-motif containing proteins Scd6 and Psp2 act as suppressors of clathrin heavy chain deficiency. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2022; 1869:119327. [PMID: 35901970 DOI: 10.1016/j.bbamcr.2022.119327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2022] [Revised: 07/05/2022] [Accepted: 07/11/2022] [Indexed: 06/15/2023]
Abstract
Clathrin, made up of the heavy- and light-chains, constitutes one of the most abundant proteins involved in intracellular protein trafficking and endocytosis. YPR129W, which encodes RGG-motif containing translation repressor was identified as a part of the multi-gene construct (SCD6) that suppressed clathrin deficiency. However, the contribution of YPR129W alone in suppressing clathrin deficiency has not been documented. This study identifies YPR129W as a necessary and sufficient gene in a multi-gene construct SCD6 that suppresses clathrin deficiency. Importantly, we also identify cytoplasmic RGG-motif protein encoding gene PSP2 as another novel suppressor of clathrin deficiency. Detailed domain analysis of the two suppressors reveals that the RGG-motif of both Scd6 and Psp2 is important for suppressing clathrin deficiency. Interestingly, the endocytosis function of clathrin heavy chain assayed by internalization of GFP-Snc1 and α-factor secretion activity are not complemented by either Scd6 or Psp2. We further observe that inhibition of TORC1 compromises the suppression activity of both SCD6 and PSP2 to different extent, suggesting that two suppressors are differentially regulated. Scd6 granules increased based on its RGG-motif upon Chc1 depletion. Strikingly, Psp2 overexpression increased the abundance of ubiquitin-conjugated proteins in Chc1 depleted cells in its RGG-motif dependent manner and also decreased the accumulation of GFP-Atg8 foci. Overall based on our results using SCD6 and PSP2, we identify a novel role of RGG-motif containing proteins in suppressing clathrin deficiency. Since both the suppressors are RNA-binding proteins, this study opens an exciting avenue for exploring the connection between clathrin function and post-transcriptional gene control processes.
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Affiliation(s)
- Mani Garg
- Department of Biochemistry, Indian Institute of Science, C V Raman road, Bangalore 560012, India
| | - Debadrita Roy
- Department of Biochemistry, Indian Institute of Science, C V Raman road, Bangalore 560012, India
| | - Purusharth I Rajyaguru
- Department of Biochemistry, Indian Institute of Science, C V Raman road, Bangalore 560012, India.
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10
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Eising S, Esch B, Wälte M, Vargas Duarte P, Walter S, Ungermann C, Bohnert M, Fröhlich F. A lysosomal biogenesis map reveals the cargo spectrum of yeast vacuolar protein targeting pathways. J Cell Biol 2022; 221:213011. [PMID: 35175277 PMCID: PMC8859911 DOI: 10.1083/jcb.202107148] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 12/20/2021] [Accepted: 01/18/2022] [Indexed: 12/15/2022] Open
Abstract
The lysosome is the major catabolic organelle in the cell that has been established as a key metabolic signaling center. Mutations in many lysosomal proteins have catastrophic effects and cause neurodegeneration, cancer, and age-related diseases. The vacuole is the lysosomal analog of Saccharomyces cerevisiae that harbors many evolutionary conserved proteins. Proteins reach vacuoles via the Vps10-dependent endosomal vacuolar protein sorting pathway, via the alkaline phosphatase (ALP or AP-3) pathway, and via the cytosol-to-vacuole transport (CVT) pathway. A systematic understanding of the cargo spectrum of each pathway is completely lacking. Here, we use quantitative proteomics of purified vacuoles to generate the yeast lysosomal biogenesis map. This dataset harbors information on the cargo-receptor relationship of almost all vacuolar proteins. We map binding motifs of Vps10 and the AP-3 complex and identify a novel cargo of the CVT pathway under nutrient-rich conditions. Our data show how organelle purification and quantitative proteomics can uncover fundamental insights into organelle biogenesis.
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Affiliation(s)
- Sebastian Eising
- Molecular Membrane Biology Group, Department of Biology/Chemistry, Osnabrück University, Osnabrück, Germany
| | - Bianca Esch
- Molecular Membrane Biology Group, Department of Biology/Chemistry, Osnabrück University, Osnabrück, Germany
| | - Mike Wälte
- Institute of Cell Dynamics and Imaging, University of Münster, Münster, Germany
| | - Prado Vargas Duarte
- Biochemistry Section, Department of Biology/Chemistry, Osnabrück University, Osnabrück, Germany
| | - Stefan Walter
- Center of Cellular Nanoanalytics Osnabrück, Osnabrück University, Osnabrück, Germany
| | - Christian Ungermann
- Biochemistry Section, Department of Biology/Chemistry, Osnabrück University, Osnabrück, Germany.,Center of Cellular Nanoanalytics Osnabrück, Osnabrück University, Osnabrück, Germany
| | - Maria Bohnert
- Institute of Cell Dynamics and Imaging, University of Münster, Münster, Germany.,Cells in Motion Interfaculty Centre, University of Münster, Münster, Germany
| | - Florian Fröhlich
- Molecular Membrane Biology Group, Department of Biology/Chemistry, Osnabrück University, Osnabrück, Germany.,Biochemistry Section, Department of Biology/Chemistry, Osnabrück University, Osnabrück, Germany
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11
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Nekrakalaya B, Arefian M, Kotimoole CN, Krishna RM, Palliyath GK, Najar MA, Behera SK, Kasaragod S, Santhappan P, Hegde V, Prasad TSK. Towards Phytopathogen Diagnostics? Coconut Bud Rot Pathogen Phytophthora palmivora Mycelial Proteome Analysis Informs Genome Annotation. OMICS : A JOURNAL OF INTEGRATIVE BIOLOGY 2022; 26:189-203. [PMID: 35353641 DOI: 10.1089/omi.2021.0208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Planetary agriculture stands to benefit immensely from phytopathogen diagnostics, which would enable early detection of pathogens with harmful effects on crops. For example, Phytophthora palmivora is one of the most destructive phytopathogens affecting many economically important tropical crops such as coconut. P. palmivora causes diseases in over 200 host plants, and notably, the bud rot disease in coconut and oil palm, which is often lethal because it is usually detected at advanced stages of infection. Limited availability of large-scale omics datasets for P. palmivora is an important barrier for progress toward phytopathogen diagnostics. We report here the mycelial proteome of P. palmivora using high-resolution mass spectrometry analysis. We identified 8073 proteins in the mycelium. Gene Ontology-based functional classification of detected proteins revealed 4884, 4981, and 3044 proteins, respectively, with roles in biological processes, molecular functions, and cellular components. Proteins such as P-loop, NTPase, and WD40 domains with key roles in signal transduction pathways were identified. KEGG pathway analysis annotated 2467 proteins to various signaling pathways, such as phosphatidylinositol, Ca2+, and mitogen-activated protein kinase, and autophagy and cell cycle. These molecular substrates might possess vital roles in filamentous growth, sporangia formation, degradation of damaged cellular content, and recycling of nutrients in P. palmivora. This large-scale proteomics data and analyses pave the way for new insights on biology, genome annotation, and vegetative growth of the important plant pathogen P. palmivora. They also can help accelerate research on future phytopathogen diagnostics and preventive interventions.
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Affiliation(s)
- Bhagya Nekrakalaya
- Centre for Systems Biology and Molecular Medicine, Yenepoya Research Centre, Yenepoya (Deemed to be University), Mangalore, India
| | - Mohammad Arefian
- Centre for Systems Biology and Molecular Medicine, Yenepoya Research Centre, Yenepoya (Deemed to be University), Mangalore, India
| | - Chinmaya Narayana Kotimoole
- Centre for Systems Biology and Molecular Medicine, Yenepoya Research Centre, Yenepoya (Deemed to be University), Mangalore, India
| | | | | | - Mohammad Altaf Najar
- Centre for Systems Biology and Molecular Medicine, Yenepoya Research Centre, Yenepoya (Deemed to be University), Mangalore, India
| | - Santosh Kumar Behera
- Centre for Systems Biology and Molecular Medicine, Yenepoya Research Centre, Yenepoya (Deemed to be University), Mangalore, India
| | - Sandeep Kasaragod
- Centre for Systems Biology and Molecular Medicine, Yenepoya Research Centre, Yenepoya (Deemed to be University), Mangalore, India
| | | | - Vinayaka Hegde
- ICAR-Central Plantation Crops Research Institute, Kasaragod, India
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12
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Li W, Hao CJ, Hao ZH, Ma J, Wang QC, Yuan YF, Gong JJ, Chen YY, Yu JY, Wei AH. New insights into the pathogenesis of Hermansky-Pudlak syndrome. Pigment Cell Melanoma Res 2022; 35:290-302. [PMID: 35129281 DOI: 10.1111/pcmr.13030] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 02/02/2022] [Accepted: 02/03/2022] [Indexed: 12/14/2022]
Abstract
Hermansky-Pudlak syndrome (HPS) is characterized by defects of multiple tissue-specific lysosome-related organelles (LROs), typically manifesting with oculocutaneous albinism or ocular albinism, bleeding tendency, and in some cases with pulmonary fibrosis, inflammatory bowel disease or immunodeficiency, neuropsychological disorders. Eleven HPS subtypes in humans and at least 15 subtypes in mice have been molecularly identified. Current understanding of the underlying mechanisms of HPS is focusing on the defective biogenesis of LROs. Compelling evidences have shown that HPS protein-associated complexes (HPACs) function in cargo transport, cargo recycling, and cargo removal to maintain LRO homeostasis. Further investigation on the molecular and cellular mechanism of LRO biogenesis and secretion will be helpful for better understanding of its pathogenesis and for the precise intervention of HPS.
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Affiliation(s)
- Wei Li
- Beijing Key Laboratory for Genetics of Birth Defects, Beijing Pediatric Research Institute, Beijing Children's Hospital, Capital Medical University, Center of Rare Diseases, National Center for Children's Health, Beijing, China.,MOE Key Laboratory of Major Diseases in Children, Capital Medical University, Beijing, China
| | - Chan-Juan Hao
- Beijing Key Laboratory for Genetics of Birth Defects, Beijing Pediatric Research Institute, Beijing Children's Hospital, Capital Medical University, Center of Rare Diseases, National Center for Children's Health, Beijing, China.,MOE Key Laboratory of Major Diseases in Children, Capital Medical University, Beijing, China
| | - Zhen-Hua Hao
- Beijing Key Laboratory for Genetics of Birth Defects, Beijing Pediatric Research Institute, Beijing Children's Hospital, Capital Medical University, Center of Rare Diseases, National Center for Children's Health, Beijing, China.,MOE Key Laboratory of Major Diseases in Children, Capital Medical University, Beijing, China
| | - Jing Ma
- Beijing Key Laboratory for Genetics of Birth Defects, Beijing Pediatric Research Institute, Beijing Children's Hospital, Capital Medical University, Center of Rare Diseases, National Center for Children's Health, Beijing, China.,MOE Key Laboratory of Major Diseases in Children, Capital Medical University, Beijing, China
| | - Qiao-Chu Wang
- Beijing Key Laboratory for Genetics of Birth Defects, Beijing Pediatric Research Institute, Beijing Children's Hospital, Capital Medical University, Center of Rare Diseases, National Center for Children's Health, Beijing, China.,MOE Key Laboratory of Major Diseases in Children, Capital Medical University, Beijing, China
| | - Ye-Feng Yuan
- Beijing Key Laboratory for Genetics of Birth Defects, Beijing Pediatric Research Institute, Beijing Children's Hospital, Capital Medical University, Center of Rare Diseases, National Center for Children's Health, Beijing, China.,MOE Key Laboratory of Major Diseases in Children, Capital Medical University, Beijing, China
| | - Juan-Juan Gong
- Beijing Key Laboratory for Genetics of Birth Defects, Beijing Pediatric Research Institute, Beijing Children's Hospital, Capital Medical University, Center of Rare Diseases, National Center for Children's Health, Beijing, China.,MOE Key Laboratory of Major Diseases in Children, Capital Medical University, Beijing, China
| | - Yuan-Ying Chen
- Beijing Key Laboratory for Genetics of Birth Defects, Beijing Pediatric Research Institute, Beijing Children's Hospital, Capital Medical University, Center of Rare Diseases, National Center for Children's Health, Beijing, China.,MOE Key Laboratory of Major Diseases in Children, Capital Medical University, Beijing, China
| | - Jia-Ying Yu
- Beijing Key Laboratory for Genetics of Birth Defects, Beijing Pediatric Research Institute, Beijing Children's Hospital, Capital Medical University, Center of Rare Diseases, National Center for Children's Health, Beijing, China.,MOE Key Laboratory of Major Diseases in Children, Capital Medical University, Beijing, China
| | - Ai-Hua Wei
- Department of Dermatology, Tongren Hospital, Capital Medical University, Beijing, China
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13
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Ishida H, Okashita Y, Ishida H, Hayashi M, Izumi M, Makino A, Bhuiyan NH, van Wijk KJ. GFS9 Affects Piecemeal Autophagy of Plastids in Young Seedlings of Arabidopsis thaliana. PLANT & CELL PHYSIOLOGY 2021; 62:1372-1386. [PMID: 34086965 DOI: 10.1093/pcp/pcab084] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 05/26/2021] [Accepted: 06/04/2021] [Indexed: 06/12/2023]
Abstract
Chloroplasts, and plastids in general, contain abundant protein pools that can be major sources of carbon and nitrogen for recycling. We have previously shown that chloroplasts are partially and sequentially degraded by piecemeal autophagy via the Rubisco-containing body. This degradation occurs during plant development and in response to the environment; however, little is known about the fundamental underlying mechanisms. To discover the mechanisms of piecemeal autophagy of chloroplasts/plastids, we conducted a forward-genetics screen following ethyl-methanesulfonate mutagenesis of an Arabidopsis (Arabidopsis thaliana) transgenic line expressing chloroplast-targeted green fluorescent protein (CT-GFP). This screen allowed us to isolate a mutant, gfs9-5, which hyperaccumulated cytoplasmic bodies labeled with CT-GFP of up to 1.0 μm in diameter in the young seedlings. We termed these structures plastid bodies (PBs). The mutant was defective in a membrane-trafficking factor, green fluorescent seed 9 (GFS9), and PB accumulation in gfs9-5 was promoted by darkness and nutrient deficiency. Transmission electron microscopy indicated that gfs9-5 hyperaccumulated structures corresponding to autophagosomes and PBs. gfs9-5 hyperaccumulated membrane-bound endogenous ATG8 proteins, transgenic yellow fluorescent protein (YFP)-ATG8e proteins and autophagosome-like structures labeled with YFP-ATG8e. The YFP-ATG8e signal was associated with the surface of plastids and their protrusions in gfs9-5. Double mutants of gfs9 and autophagy-defective 5 did not accumulate PBs. In gfs9-5, the YFP-ATG8e proteins and PBs could be delivered to the vacuole and autophagic flux was increased. We discuss a possible connection between GFS9 and autophagy and propose a potential use of gfs9-5 as a new tool to study piecemeal plastid autophagy.
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Affiliation(s)
- Hiroyuki Ishida
- Department of Applied Plant Science, Graduate School of Agricultural Science, Tohoku University, 468-1 Aramaki Aza Aoba, Sendai 980-8572, Japan
- School of Integrative Plant Sciences, Section of Plant Biology, Cornell University, Ithaca, NY 14853, USA
| | - Yu Okashita
- Department of Applied Plant Science, Graduate School of Agricultural Science, Tohoku University, 468-1 Aramaki Aza Aoba, Sendai 980-8572, Japan
| | - Hiromi Ishida
- Department of Applied Plant Science, Graduate School of Agricultural Science, Tohoku University, 468-1 Aramaki Aza Aoba, Sendai 980-8572, Japan
- School of Integrative Plant Sciences, Section of Plant Biology, Cornell University, Ithaca, NY 14853, USA
| | - Makoto Hayashi
- Department of Bioscience, Nagahama Institute of Bioscience and Technology, Tamura 1266, Nagahama, Shiga 526-0829, Japan
| | - Masanori Izumi
- Center for Sustainable Resource Science, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Amane Makino
- Department of Applied Plant Science, Graduate School of Agricultural Science, Tohoku University, 468-1 Aramaki Aza Aoba, Sendai 980-8572, Japan
| | - Nazmul H Bhuiyan
- School of Integrative Plant Sciences, Section of Plant Biology, Cornell University, Ithaca, NY 14853, USA
- Eurofins Lancaster Lab PSS, Richmond, VA, USA
| | - Klaas J van Wijk
- School of Integrative Plant Sciences, Section of Plant Biology, Cornell University, Ithaca, NY 14853, USA
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14
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Yıldız Y, Koşukcu C, Aygün D, Akçaboy M, Öztek Çelebi FZ, Taşcı Yıldız Y, Şahin G, Aytekin C, Yüksel D, Lay İ, Özgül RK, Dursun A. Homozygous missense VPS16 variant is associated with a novel disease, resembling mucopolysaccharidosis-plus syndrome in two siblings. Clin Genet 2021; 100:308-317. [PMID: 34013567 DOI: 10.1111/cge.14002] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 05/12/2021] [Accepted: 05/18/2021] [Indexed: 12/17/2022]
Abstract
Disorders of intracellular trafficking are a group of inherited disorders, which often display multisystem phenotypes. Vacuolar protein sorting (VPS) subunit C, composed of VPS11, VPS18, VPS16, and VPS33A proteins, is involved in tethering of endosomes, lysosomes, and autophagosomes. Our group and others have previously described patients with a specific homozygous missense VPS33A variant, exhibiting a storage disease phenotype resembling mucopolysaccharidosis (MPS), termed "MPS-plus syndrome." Here, we report two siblings from a consanguineous Turkish-Arabic family, who have overlapping features of MPS and intracellular trafficking disorders, including short stature, coarse facies, developmental delay, peripheral neuropathy, splenomegaly, spondylar dysplasia, congenital neutropenia, and high-normal glycosaminoglycan excretion. Whole exome sequencing and familial segregation analyses led to the homozygous NM_022575.3:c.540G>T; p.Trp180Cys variant in VPS16 in both siblings. Multiple bioinformatic methods supported the pathogenicity of this variant. Different monoallelic null VPS16 variants and a homozygous missense VPS16 variant had been previously associated with dystonia. A biallelic intronic, probably splice-altering variant in VPS16, causing an MPS-plus syndrome-like disease has been very recently reported in two individuals. The siblings presented herein display no dystonia, but have features of a multisystem storage disorder, representing a novel MPS-plus syndrome-like disease, associated for the first time with VPS16 missense variants.
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Affiliation(s)
- Yılmaz Yıldız
- Division of Pediatric Metabolism, Department of Pediatrics, Faculty of Medicine, Hacettepe University, Ankara, Turkey.,Department of Pediatric Metabolic Diseases, Dr. Sami Ulus Training and Research Hospital for Maternity and Child Health, Ankara, Turkey
| | - Can Koşukcu
- Division of Pediatric Metabolism, Department of Pediatrics, Faculty of Medicine, Hacettepe University, Ankara, Turkey.,Department of Bioinformatics, Institute of Health Sciences, Hacettepe University, Ankara, Turkey
| | - Damla Aygün
- Division of Pediatric Metabolism, Department of Pediatrics, Faculty of Medicine, Hacettepe University, Ankara, Turkey
| | - Meltem Akçaboy
- Department of Pediatrics, Dr. Sami Ulus Training and Research Hospital for Maternity and Child Health, Ankara, Turkey
| | - Fatma Zehra Öztek Çelebi
- Department of Pediatrics, Dr. Sami Ulus Training and Research Hospital for Maternity and Child Health, Ankara, Turkey
| | - Yasemin Taşcı Yıldız
- Department of Pediatric Radiology, Dr. Sami Ulus Training and Research Hospital for Maternity and Child Health, Ankara, Turkey
| | - Gülseren Şahin
- Department of Pediatric Gastroenterology, Dr. Sami Ulus Training and Research Hospital for Maternity and Child Health, Ankara, Turkey
| | - Caner Aytekin
- Department of Pediatric Allergy and Immunology, Dr. Sami Ulus Training and Research Hospital for Maternity and Child Health, Ankara, Turkey
| | - Deniz Yüksel
- Department of Pediatric Neurology, Dr. Sami Ulus Training and Research Hospital for Maternity and Child Health, Ankara, Turkey
| | - İncilay Lay
- Department of Medical Biochemistry, Faculty of Medicine, Hacettepe University, Ankara, Turkey
| | - Rıza Köksal Özgül
- Division of Pediatric Metabolism, Department of Pediatrics, Faculty of Medicine, Hacettepe University, Ankara, Turkey.,Institute of Child Health, Hacettepe University, Ankara, Turkey
| | - Ali Dursun
- Division of Pediatric Metabolism, Department of Pediatrics, Faculty of Medicine, Hacettepe University, Ankara, Turkey
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15
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Burns CH, Yau B, Rodriguez A, Triplett J, Maslar D, An YS, van der Welle REN, Kossina RG, Fisher MR, Strout GW, Bayguinov PO, Veenendaal T, Chitayat D, Fitzpatrick JAJ, Klumperman J, Kebede MA, Asensio CS. Pancreatic β-Cell-Specific Deletion of VPS41 Causes Diabetes Due to Defects in Insulin Secretion. Diabetes 2021; 70:436-448. [PMID: 33168621 PMCID: PMC7881869 DOI: 10.2337/db20-0454] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Accepted: 11/03/2020] [Indexed: 12/14/2022]
Abstract
Insulin secretory granules (SGs) mediate the regulated secretion of insulin, which is essential for glucose homeostasis. The basic machinery responsible for this regulated exocytosis consists of specific proteins present both at the plasma membrane and on insulin SGs. The protein composition of insulin SGs thus dictates their release properties, yet the mechanisms controlling insulin SG formation, which determine this molecular composition, remain poorly understood. VPS41, a component of the endolysosomal tethering homotypic fusion and vacuole protein sorting (HOPS) complex, was recently identified as a cytosolic factor involved in the formation of neuroendocrine and neuronal granules. We now find that VPS41 is required for insulin SG biogenesis and regulated insulin secretion. Loss of VPS41 in pancreatic β-cells leads to a reduction in insulin SG number, changes in their transmembrane protein composition, and defects in granule-regulated exocytosis. Exploring a human point mutation, identified in patients with neurological but no endocrine defects, we show that the effect on SG formation is independent of HOPS complex formation. Finally, we report that mice with a deletion of VPS41 specifically in β-cells develop diabetes due to severe depletion of insulin SG content and a defect in insulin secretion. In sum, our data demonstrate that VPS41 contributes to glucose homeostasis and metabolism.
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Affiliation(s)
| | - Belinda Yau
- Discipline of Physiology, School of Medical Sciences, Charles Perkins Centre, The University of Sydney, Camperdown, New South Wales, Australia
| | | | - Jenna Triplett
- Department of Biological Sciences, University of Denver, Denver, CO
| | - Drew Maslar
- Department of Biological Sciences, University of Denver, Denver, CO
| | - You Sun An
- Discipline of Physiology, School of Medical Sciences, Charles Perkins Centre, The University of Sydney, Camperdown, New South Wales, Australia
| | - Reini E N van der Welle
- Section of Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Ross G Kossina
- Washington University Center for Cellular Imaging, Washington University School of Medicine, St. Louis, MO
| | - Max R Fisher
- Washington University Center for Cellular Imaging, Washington University School of Medicine, St. Louis, MO
| | - Gregory W Strout
- Washington University Center for Cellular Imaging, Washington University School of Medicine, St. Louis, MO
| | - Peter O Bayguinov
- Washington University Center for Cellular Imaging, Washington University School of Medicine, St. Louis, MO
| | - Tineke Veenendaal
- Section of Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - David Chitayat
- Division of Clinical and Metabolic Genetics, Department of Pediatrics, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
- Prenatal Diagnosis and Medical Genetics Program, Department of Obstetrics and Gynaecology, University of Toronto, Toronto, Ontario, Canada
| | - James A J Fitzpatrick
- Washington University Center for Cellular Imaging, Washington University School of Medicine, St. Louis, MO
- Departments of Neuroscience and Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO
| | - Judith Klumperman
- Section of Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Melkam A Kebede
- Discipline of Physiology, School of Medical Sciences, Charles Perkins Centre, The University of Sydney, Camperdown, New South Wales, Australia
| | - Cedric S Asensio
- Department of Biological Sciences, University of Denver, Denver, CO
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16
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Füllbrunn N, Li Z, Jorde L, Richter CP, Kurre R, Langemeyer L, Yu C, Meyer C, Enderlein J, Ungermann C, Piehler J, You C. Nanoscopic anatomy of dynamic multi-protein complexes at membranes resolved by graphene-induced energy transfer. eLife 2021; 10:62501. [PMID: 33513092 PMCID: PMC7847308 DOI: 10.7554/elife.62501] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 12/28/2020] [Indexed: 11/30/2022] Open
Abstract
Insights into the conformational organization and dynamics of proteins complexes at membranes is essential for our mechanistic understanding of numerous key biological processes. Here, we introduce graphene-induced energy transfer (GIET) to probe axial orientation of arrested macromolecules at lipid monolayers. Based on a calibrated distance-dependent efficiency within a dynamic range of 25 nm, we analyzed the conformational organization of proteins and complexes involved in tethering and fusion at the lysosome-like yeast vacuole. We observed that the membrane-anchored Rab7-like GTPase Ypt7 shows conformational reorganization upon interactions with effector proteins. Ensemble and time-resolved single-molecule GIET experiments revealed that the HOPS tethering complex, when recruited via Ypt7 to membranes, is dynamically alternating between a ‘closed’ and an ‘open’ conformation, with the latter possibly interacting with incoming vesicles. Our work highlights GIET as a unique spectroscopic ruler to reveal the axial orientation and dynamics of macromolecular complexes at biological membranes with sub-nanometer resolution. Proteins are part of the building blocks of life and are essential for structure, function and regulation of every cell, tissue and organ of the body. Proteins adopt different conformations to work efficiently within the various environments of a cell. They can also switch between shapes. One way to monitor how proteins change their shapes involves energy transfer. This approach can measure how close two proteins, or two parts of the same protein, are, by using dye labels that respond to each other when they are close together. For example, in a method called FRET, one dye label absorbs light and transfers the energy to the other label, which emits it as a different color of light. However, FRET only works over short distances (less than 10nm apart or 1/100,000th of a millimeter), so it is not useful for larger proteins. Here, Füllbrunn, Li et al. developed a method called GIET that uses graphene to analyze the dynamic structures of proteins on membrane surfaces. Graphene is a type of carbon nanomaterial that can absorb energy from dye labels and could provide a way to study protein interactions over longer distances. Graphene was deposited on a glass surface where it was coated with single layer of membrane, which could then be used to capture specific proteins. The results showed that GIET worked over longer distances (up to 30 nm) than FRET and could be used to study proteins attached to the membrane around graphene. Füllbrunn, Li et al. used it to examine a specific complex of proteins called HOPS, which is linked to multiple diseases, including Ebola, measuring distances between the head or tail of HOPS and the membrane to understand protein shapes. This revealed that HOPS adopts an upright position on membranes and alternates between open and closed shapes. The study of Füllbrunn, Li et al. highlights the ability of GIET to address unanswered questions about the function of protein complexes on membrane surfaces and sheds new light on the structural dynamics of HOPS in living cells. As it allows protein interactions to be studied over much greater distances, GIET could be a powerful new tool for cell biology research. Moreover, graphene is also useful in electron microscopy and both approaches combined could achieve a detailed structural picture of proteins in action.
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Affiliation(s)
- Nadia Füllbrunn
- Department of Biology/Chemistry, University of Osnabrück, Osnabrück, Germany.,Center of Cellular Nanoanalytics (CellNanOs), University of Osnabrück, Osnabrück, Germany
| | - Zehao Li
- Department of Biology/Chemistry, University of Osnabrück, Osnabrück, Germany.,Center of Cellular Nanoanalytics (CellNanOs), University of Osnabrück, Osnabrück, Germany.,College of Life Sciences, Beijing University of Chemical Technology, Beijing, China
| | - Lara Jorde
- Department of Physics, University of Osnabrück, Osnabrück, Germany
| | - Christian P Richter
- Department of Biology/Chemistry, University of Osnabrück, Osnabrück, Germany
| | - Rainer Kurre
- Department of Biology/Chemistry, University of Osnabrück, Osnabrück, Germany.,Center of Cellular Nanoanalytics (CellNanOs), University of Osnabrück, Osnabrück, Germany
| | - Lars Langemeyer
- Department of Biology/Chemistry, University of Osnabrück, Osnabrück, Germany
| | - Changyuan Yu
- College of Life Sciences, Beijing University of Chemical Technology, Beijing, China
| | - Carola Meyer
- Center of Cellular Nanoanalytics (CellNanOs), University of Osnabrück, Osnabrück, Germany.,Department of Physics, University of Osnabrück, Osnabrück, Germany
| | - Jörg Enderlein
- 3rd Institute of Physics - Biophysics, Georg August University, Göttingen, Germany.,Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), Georg August University, Göttingen, Germany
| | - Christian Ungermann
- Department of Biology/Chemistry, University of Osnabrück, Osnabrück, Germany.,Center of Cellular Nanoanalytics (CellNanOs), University of Osnabrück, Osnabrück, Germany
| | - Jacob Piehler
- Department of Biology/Chemistry, University of Osnabrück, Osnabrück, Germany.,Center of Cellular Nanoanalytics (CellNanOs), University of Osnabrück, Osnabrück, Germany
| | - Changjiang You
- Department of Biology/Chemistry, University of Osnabrück, Osnabrück, Germany.,Center of Cellular Nanoanalytics (CellNanOs), University of Osnabrück, Osnabrück, Germany
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17
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Salassa BN, Cueto JA, Gambarte Tudela J, Romano PS. Endocytic Rabs Are Recruited to the Trypanosoma cruzi Parasitophorous Vacuole and Contribute to the Process of Infection in Non-professional Phagocytic Cells. Front Cell Infect Microbiol 2020; 10:536985. [PMID: 33194787 PMCID: PMC7658340 DOI: 10.3389/fcimb.2020.536985] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Accepted: 09/17/2020] [Indexed: 12/14/2022] Open
Abstract
Trypanosoma cruzi is the parasite causative of Chagas disease, a highly disseminated illness endemic in Latin-American countries. T. cruzi has a complex life cycle that involves mammalian hosts and insect vectors both of which exhibits different parasitic forms. Trypomastigotes are the infective forms capable to invade several types of host cells from mammals. T. cruzi infection process comprises two sequential steps, the formation and the maturation of the Trypanosoma cruzi parasitophorous vacuole. Host Rab GTPases are proteins that control the intracellular vesicular traffic by regulating budding, transport, docking, and tethering of vesicles. From over 70 Rab GTPases identified in mammalian cells only two, Rab5 and Rab7 have been found in the T. cruzi vacuole to date. In this work, we have characterized the role of the endocytic, recycling, and secretory routes in the T. cruzi infection process in CHO cells, by studying the most representative Rabs of these pathways. We found that endocytic Rabs are selectively recruited to the vacuole of T. cruzi, among them Rab22a, Rab5, and Rab21 right away after the infection followed by Rab7 and Rab39a at later times. However, neither recycling nor secretory Rabs were present in the vacuole membrane at the times studied. Interestingly loss of function of endocytic Rabs by the use of their dominant-negative mutant forms significantly decreases T. cruzi infection. These data highlight the contribution of these proteins and the endosomal route in the process of T. cruzi infection.
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Affiliation(s)
- Betiana Nebaí Salassa
- Laboratorio de Biología de Trypanosoma cruzi la célula hospedadora, Instituto de Histología y Embriologìa, Consejo Nacional de Investigaciones Científicas y Técnicas (IHEM-CONICET), Universidad Nacional de Cuyo, Mendoza, Argentina.,Facultad de Odontología, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Juan Agustín Cueto
- Laboratorio de Biología de Trypanosoma cruzi la célula hospedadora, Instituto de Histología y Embriologìa, Consejo Nacional de Investigaciones Científicas y Técnicas (IHEM-CONICET), Universidad Nacional de Cuyo, Mendoza, Argentina.,Instituto de Fisiología, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Julián Gambarte Tudela
- Instituto de Bioquímica y Biotecnología, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Patricia Silvia Romano
- Laboratorio de Biología de Trypanosoma cruzi la célula hospedadora, Instituto de Histología y Embriologìa, Consejo Nacional de Investigaciones Científicas y Técnicas (IHEM-CONICET), Universidad Nacional de Cuyo, Mendoza, Argentina.,Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina
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18
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Lőrincz P, Juhász G. Autophagosome-Lysosome Fusion. J Mol Biol 2020; 432:2462-2482. [DOI: 10.1016/j.jmb.2019.10.028] [Citation(s) in RCA: 98] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 10/11/2019] [Accepted: 10/15/2019] [Indexed: 12/26/2022]
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19
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Wu LX, Wei CC, Yang SB, Zhao T, Luo Z. Effects of Fat and Fatty Acids on the Formation of Autolysosomes in the Livers from Yellow Catfish Pelteobagrus Fulvidraco. Genes (Basel) 2019; 10:E751. [PMID: 31557940 PMCID: PMC6826758 DOI: 10.3390/genes10100751] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Revised: 09/14/2019] [Accepted: 09/23/2019] [Indexed: 02/06/2023] Open
Abstract
The autophagy-lysosome pathway, which involves many crucial genes and proteins, plays crucial roles in the maintenance of intracellular homeostasis by the degradation of damaged components. At present, some of these genes and proteins have been identified but their specific functions are largely unknown. This study was performed to clone and characterize the full-length cDNA sequences of nine key autolysosome-related genes (vps11, vps16, vps18, vps33b, vps41, lamp1, mcoln1, ctsd1 and tfeb) from yellow catfish Pelteobagrus fulvidraco. The expression of these genes and the transcriptional responses to a high-fat diet and fatty acids (FAs) (palmitic acid (PA) and oleic acid (OA)) were investigated. The mRNAs of these genes could be detected in heart, liver, muscle, spleen, brain, mesenteric adipose tissue, intestine, kidney and ovary, but varied with the tissues. In the liver, the mRNA levels of the nine autolysosome-related genes were lower in fish fed a high-fat diet than those fed the control, indicating that a high-fat diet inhibited formation of autolysosomes. Palmitic acid (a saturated FA) significantly inhibited the formation of autolysosomes at 12 h, 24 h and 48 h incubation. In contrast, oleic acid (an unsaturated FA) significantly induced the formation of autolysosomes at 12 h, but inhibited them at 24 h. At 48 h, the effects of OA incubation on autolysosomes were OA concentration-dependent in primary hepatocytes of P. fulvidraco. The results of flow cytometry and laser confocal observations confirmed these results. PA and OA incubation also increased intracellular non-esterified fatty acid (NEFA) concentration at 12 h, 24 h and 48 h, and influenced mRNA levels of fatty acid binding protein (fabp) and fatty acid transport protein 4 (fatp4) which facilitate FA transport in primary hepatocytes of P. fulvidraco. The present study demonstrated the molecular characterization of the nine autolysosome-related genes and their transcriptional responses to fat and FAs in fish, which provides the basis for further exploring their regulatory mechanism in vertebrates.
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Affiliation(s)
- Li-Xiang Wu
- Laboratory of Molecular Nutrition for Aquatic Economic Animals, Fishery College, Huazhong Agricultural University, Wuhan 430070, China.
| | - Chuan-Chuan Wei
- Laboratory of Molecular Nutrition for Aquatic Economic Animals, Fishery College, Huazhong Agricultural University, Wuhan 430070, China.
| | - Shui-Bo Yang
- Laboratory of Molecular Nutrition for Aquatic Economic Animals, Fishery College, Huazhong Agricultural University, Wuhan 430070, China.
| | - Tao Zhao
- Laboratory of Molecular Nutrition for Aquatic Economic Animals, Fishery College, Huazhong Agricultural University, Wuhan 430070, China.
| | - Zhi Luo
- Laboratory of Molecular Nutrition for Aquatic Economic Animals, Fishery College, Huazhong Agricultural University, Wuhan 430070, China.
- Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China.
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20
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Pavlova EV, Shatunov A, Wartosch L, Moskvina AI, Nikolaeva LE, Bright NA, Tylee KL, Church HJ, Ballabio A, Luzio JP, Cox TM. The lysosomal disease caused by mutant VPS33A. Hum Mol Genet 2019; 28:2514-2530. [PMID: 31070736 PMCID: PMC6644154 DOI: 10.1093/hmg/ddz077] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Revised: 04/04/2019] [Accepted: 04/05/2019] [Indexed: 12/14/2022] Open
Abstract
A rare lysosomal disease resembling a mucopolysaccharidosis with unusual systemic features, including renal disease and platelet dysfunction, caused by the defect in a conserved region of the VPS33A gene on human chromosome 12q24.31, occurs in Yakuts-a nomadic Turkic ethnic group of Southern Siberia. VPS33A is a core component of the class C core vacuole/endosome tethering (CORVET) and the homotypic fusion and protein sorting (HOPS) complexes, which have essential functions in the endocytic pathway. Here we show that cultured fibroblasts from patients with this disorder have morphological changes: vacuolation with disordered endosomal/lysosomal compartments and-common to sphingolipid diseases-abnormal endocytic trafficking of lactosylceramide. Urine glycosaminoglycan studies revealed a pathological excess of sialylated conjugates as well as dermatan and heparan sulphate. Lipidomic screening showed elevated β-D-galactosylsphingosine with unimpaired activity of cognate lysosomal hydrolases. The 3D crystal structure of human VPS33A predicts that replacement of arginine 498 by tryptophan will de-stabilize VPS33A folding. We observed that the missense mutation reduced the abundance of full-length VPS33A and other components of the HOPS and CORVET complexes. Treatment of HeLa cells stably expressing the mutant VPS33A with a proteasome inhibitor rescued the mutant protein from degradation. We propose that the disease is due to diminished intracellular abundance of intact VPS33A. Exposure of patient-derived fibroblasts to the clinically approved proteasome inhibitor, bortezomib, or inhibition of glucosylceramide synthesis with eliglustat, partially corrected the impaired lactosylceramide trafficking defect and immediately suggest therapeutic avenues to explore in this fatal orphan disease.
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Affiliation(s)
- Elena V Pavlova
- Department of Medicine, University of Cambridge, Cambridge, UK
| | - Aleksey Shatunov
- Department of Basic and Clinical Neuroscience, Maurice Wohl Clinical Neuroscience Institute, King’s College London, London, UK
| | - Lena Wartosch
- Cambridge Institute for Medical Research and Department of Clinical Biochemistry, Wellcome Trust/MRC Building, University of Cambridge, Cambridge, UK
| | - Alena I Moskvina
- Paediatric Centre, National Medical Centre of the Republic of Sakha, Yakutsk, Russia
| | - Lena E Nikolaeva
- Paediatric Centre, National Medical Centre of the Republic of Sakha, Yakutsk, Russia
| | - Nicholas A Bright
- Cambridge Institute for Medical Research and Department of Clinical Biochemistry, Wellcome Trust/MRC Building, University of Cambridge, Cambridge, UK
| | - Karen L Tylee
- Willink Biochemical Genetics Unit, Genomic Diagnostics Laboratory, Manchester Centre for Genomic Medicine, Central Manchester University Hospitals NHS Foundation Trust, St Mary's Hospital, Manchester, UK
| | - Heather J Church
- Willink Biochemical Genetics Unit, Genomic Diagnostics Laboratory, Manchester Centre for Genomic Medicine, Central Manchester University Hospitals NHS Foundation Trust, St Mary's Hospital, Manchester, UK
| | - Andrea Ballabio
- Telethon Institute of Genetics and Medicine, Pozzuoli, Italy
| | - J Paul Luzio
- Cambridge Institute for Medical Research and Department of Clinical Biochemistry, Wellcome Trust/MRC Building, University of Cambridge, Cambridge, UK
| | - Timothy M Cox
- Department of Medicine, University of Cambridge, Cambridge, UK
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21
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Lőrincz P, Kenéz LA, Tóth S, Kiss V, Varga Á, Csizmadia T, Simon-Vecsei Z, Juhász G. Vps8 overexpression inhibits HOPS-dependent trafficking routes by outcompeting Vps41/Lt. eLife 2019; 8:45631. [PMID: 31194677 PMCID: PMC6592680 DOI: 10.7554/elife.45631] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 06/13/2019] [Indexed: 01/31/2023] Open
Abstract
Two related multisubunit tethering complexes promote endolysosomal trafficking in all eukaryotes: Rab5-binding CORVET that was suggested to transform into Rab7-binding HOPS. We have previously identified miniCORVET, containing Drosophila Vps8 and three shared core proteins, which are required for endosome maturation upstream of HOPS in highly endocytic cells (Lőrincz et al., 2016a). Here, we show that Vps8 overexpression inhibits HOPS-dependent trafficking routes including late endosome maturation, autophagosome-lysosome fusion, crinophagy and lysosome-related organelle formation. Mechanistically, Vps8 overexpression abolishes the late endosomal localization of HOPS-specific Vps41/Lt and prevents HOPS assembly. Proper ratio of Vps8 to Vps41 is thus critical because Vps8 negatively regulates HOPS by outcompeting Vps41. Endosomal recruitment of miniCORVET- or HOPS-specific subunits requires proper complex assembly, and Vps8/miniCORVET is dispensable for autophagy, crinophagy and lysosomal biogenesis. These data together indicate the recruitment of these complexes to target membranes independent of each other in Drosophila, rather than their transformation during vesicle maturation.
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Affiliation(s)
- Péter Lőrincz
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest, Hungary.,Premium Postdoctoral Research Program, Hungarian Academy of Sciences, Budapest, Hungary
| | - Lili Anna Kenéz
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest, Hungary
| | - Sarolta Tóth
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest, Hungary
| | - Viktória Kiss
- Institute of Genetics, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - Ágnes Varga
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest, Hungary
| | - Tamás Csizmadia
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest, Hungary
| | - Zsófia Simon-Vecsei
- 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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22
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van der Beek J, Jonker C, van der Welle R, Liv N, Klumperman J. CORVET, CHEVI and HOPS – multisubunit tethers of the endo-lysosomal system in health and disease. J Cell Sci 2019; 132:132/10/jcs189134. [DOI: 10.1242/jcs.189134] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
ABSTRACT
Multisubunit tethering complexes (MTCs) are multitasking hubs that form a link between membrane fusion, organelle motility and signaling. CORVET, CHEVI and HOPS are MTCs of the endo-lysosomal system. They regulate the major membrane flows required for endocytosis, lysosome biogenesis, autophagy and phagocytosis. In addition, individual subunits control complex-independent transport of specific cargoes and exert functions beyond tethering, such as attachment to microtubules and SNARE activation. Mutations in CHEVI subunits lead to arthrogryposis, renal dysfunction and cholestasis (ARC) syndrome, while defects in CORVET and, particularly, HOPS are associated with neurodegeneration, pigmentation disorders, liver malfunction and various forms of cancer. Diseases and phenotypes, however, vary per affected subunit and a concise overview of MTC protein function and associated human pathologies is currently lacking. Here, we provide an integrated overview on the cellular functions and pathological defects associated with CORVET, CHEVI or HOPS proteins, both with regard to their complexes and as individual subunits. The combination of these data provides novel insights into how mutations in endo-lysosomal proteins lead to human pathologies.
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Affiliation(s)
- Jan van der Beek
- Section Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, Institute for Biomembranes, Utrecht University, Utrecht 3584 CX, The Netherlands
| | - Caspar Jonker
- Section Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, Institute for Biomembranes, Utrecht University, Utrecht 3584 CX, The Netherlands
| | - Reini van der Welle
- Section Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, Institute for Biomembranes, Utrecht University, Utrecht 3584 CX, The Netherlands
| | - Nalan Liv
- Section Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, Institute for Biomembranes, Utrecht University, Utrecht 3584 CX, The Netherlands
| | - Judith Klumperman
- Section Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, Institute for Biomembranes, Utrecht University, Utrecht 3584 CX, The Netherlands
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23
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Corona AK, Jackson WT. Finding the Middle Ground for Autophagic Fusion Requirements. Trends Cell Biol 2018; 28:869-881. [PMID: 30115558 PMCID: PMC6197918 DOI: 10.1016/j.tcb.2018.07.001] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Revised: 06/29/2018] [Accepted: 07/06/2018] [Indexed: 12/26/2022]
Abstract
Autophagosome/amphisome-lysosome fusion is a highly regulated process at the protein, lipid, and biochemical level. Each primary component of fusion, such as the core SNAREs, HOPS complex, or physical positioning by microtubule-associated dynein motors, are regulated at multiple points to ensure optimum conditions for autophagic flux to proceed. With the complexity of the membrane fusion system, it is not difficult to imagine how autophagic flux defect-related disorders, such as Huntington's disease, non-familial Alzheimer's disease, and Vici syndrome develop. Each membrane fusion step is regulated at the protein, lipid, and ion level. This review aims to discuss the recent developments toward understanding the regulation of autophagosome, amphisome, and lysosome fusion requirements for successful autophagic flux.
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Affiliation(s)
- Abigail K Corona
- Department of Microbiology and Immunology, University of Maryland School of Medicine, 685 W. Baltimore Avenue, Baltimore, MD 21201, USA
| | - William T Jackson
- Department of Microbiology and Immunology, University of Maryland School of Medicine, 685 W. Baltimore Avenue, Baltimore, MD 21201, USA.
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24
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Moparthi SB, Wollert T. Reconstruction of destruction – in vitro reconstitution methods in autophagy research. J Cell Sci 2018; 132:132/4/jcs223792. [DOI: 10.1242/jcs.223792] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
ABSTRACT
Autophagy is one of the most elaborative membrane remodeling systems in eukaryotic cells. Its major function is to recycle cytoplasmic material by delivering it to lysosomes for degradation. To achieve this, a membrane cisterna is formed that gradually captures cargo such as organelles or protein aggregates. The diversity of cargo requires autophagy to be highly versatile to adapt the shape of the phagophore to its substrate. Upon closure of the phagophore, a double-membrane-surrounded autophagosome is formed that eventually fuses with lysosomes. In response to environmental cues such as cytotoxicity or starvation, bulk cytoplasm can be captured and delivered to lysosomes. Autophagy thus supports cellular survival under adverse conditions. During the past decades, groundbreaking genetic and cell biological studies have identified the core machinery involved in the process. In this Review, we are focusing on in vitro reconstitution approaches to decipher the details and spatiotemporal control of autophagy, and how such studies contributed to our current understanding of the pathways in yeast and mammals. We highlight studies that revealed the function of the autophagy machinery at a molecular level with respect to its capacity to remodel membranes.
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Affiliation(s)
- Satish Babu Moparthi
- Membrane Biochemistry and Transport, Institute Pasteur, 28 rue du Dr Roux, 75015 Paris, France
| | - Thomas Wollert
- Membrane Biochemistry and Transport, Institute Pasteur, 28 rue du Dr Roux, 75015 Paris, France
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25
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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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26
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Bas L, Papinski D, Licheva M, Torggler R, Rohringer S, Schuschnig M, Kraft C. Reconstitution reveals Ykt6 as the autophagosomal SNARE in autophagosome-vacuole fusion. J Cell Biol 2018; 217:3656-3669. [PMID: 30097514 PMCID: PMC6168255 DOI: 10.1083/jcb.201804028] [Citation(s) in RCA: 85] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Revised: 06/12/2018] [Accepted: 07/05/2018] [Indexed: 11/22/2022] Open
Abstract
Autophagy mediates the bulk degradation of cytoplasmic material, particularly during starvation. Upon the induction of autophagy, autophagosomes form a sealed membrane around cargo, fuse with a lytic compartment, and release the cargo for degradation. The mechanism of autophagosome-vacuole fusion is poorly understood, although factors that mediate other cellular fusion events have been implicated. In this study, we developed an in vitro reconstitution assay that enables systematic discovery and dissection of the players involved in autophagosome-vacuole fusion. We found that this process requires the Atg14-Vps34 complex to generate PI3P and thus recruit the Ypt7 module to autophagosomes. The HOPS-tethering complex, recruited by Ypt7, is required to prepare SNARE proteins for fusion. Furthermore, we discovered that fusion requires the R-SNARE Ykt6 on the autophagosome, together with the Q-SNAREs Vam3, Vam7, and Vti1 on the vacuole. These findings shed new light on the mechanism of autophagosome-vacuole fusion and reveal that the R-SNARE Ykt6 is required for this process.
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Affiliation(s)
- Levent Bas
- Max F. Perutz Laboratories, Vienna Biocenter, University of Vienna, Vienna, Austria
| | - Daniel Papinski
- Max F. Perutz Laboratories, Vienna Biocenter, University of Vienna, Vienna, Austria
| | - Mariya Licheva
- Institute of Biochemistry and Molecular Biology, Centre for Biochemistry and Molecular Cell Research , Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Raffaela Torggler
- Max F. Perutz Laboratories, Vienna Biocenter, University of Vienna, Vienna, Austria
- Institute of Biochemistry and Molecular Biology, Centre for Biochemistry and Molecular Cell Research , Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Sabrina Rohringer
- Max F. Perutz Laboratories, Vienna Biocenter, University of Vienna, Vienna, Austria
| | - Martina Schuschnig
- Max F. Perutz Laboratories, Vienna Biocenter, University of Vienna, Vienna, Austria
| | - Claudine Kraft
- Max F. Perutz Laboratories, Vienna Biocenter, University of Vienna, Vienna, Austria
- Institute of Biochemistry and Molecular Biology, Centre for Biochemistry and Molecular Cell Research , Faculty of Medicine, University of Freiburg, Freiburg, Germany
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27
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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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28
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VPS18 recruits VPS41 to the human HOPS complex via a RING-RING interaction. Biochem J 2017; 474:3615-3626. [PMID: 28931724 PMCID: PMC5651818 DOI: 10.1042/bcj20170588] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 09/13/2017] [Accepted: 09/15/2017] [Indexed: 02/06/2023]
Abstract
Eukaryotic cells use conserved multisubunit membrane tethering complexes, including CORVET (class C core vacuole/endosome tethering) and HOPS (homotypic fusion and vacuole protein sorting), to control the fusion of endomembranes. These complexes have been extensively studied in yeast, but to date there have been far fewer studies of metazoan CORVET and HOPS. Both of these complexes comprise six subunits: a common four-subunit core and two unique subunits. Once assembled, these complexes function to recognise specific endosomal membrane markers and facilitate SNARE-mediated membrane fusion. CORVET promotes the homotypic fusion of early endosomes, while HOPS promotes the fusion of lysosomes to late endosomes and autophagosomes. Many of the subunits of both CORVET and HOPS contain putative C-terminal zinc-finger domains. Here, the contribution of these domains to the assembly of the human CORVET and HOPS complexes has been examined. Using biochemical techniques, we demonstrate that the zinc-containing RING (really interesting new gene) domains of human VPS18 and VPS41 interact directly to form a stable heterodimer. In cells, these RING domains are able to integrate into endogenous HOPS, showing that the VPS18 RING domain is required to recruit VPS41 to the core complex subunits. Importantly, this mechanism is not conserved throughout eukaryotes, as yeast Vps41 does not contain a C-terminal zinc-finger motif. The subunit analogous to VPS41 in human CORVET is VPS8, in which the RING domain has an additional C-terminal segment that is predicted to be disordered. Both the RING and disordered C-terminal domains are required for integration of VPS8 into endogenous CORVET complexes, suggesting that HOPS and CORVET recruit VPS41 and VPS8 via distinct molecular interactions.
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29
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Schwartz ML, Nickerson DP, Lobingier BT, Plemel RL, Duan M, Angers CG, Zick M, Merz AJ. Sec17 (α-SNAP) and an SM-tethering complex regulate the outcome of SNARE zippering in vitro and in vivo. eLife 2017; 6:27396. [PMID: 28925353 PMCID: PMC5643095 DOI: 10.7554/elife.27396] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2017] [Accepted: 09/15/2017] [Indexed: 02/02/2023] Open
Abstract
Zippering of SNARE complexes spanning docked membranes is essential for most intracellular fusion events. Here, we explore how SNARE regulators operate on discrete zippering states. The formation of a metastable trans-complex, catalyzed by HOPS and its SM subunit Vps33, is followed by subsequent zippering transitions that increase the probability of fusion. Operating independently of Sec18 (NSF) catalysis, Sec17 (α-SNAP) either inhibits or stimulates SNARE-mediated fusion. If HOPS or Vps33 are absent, Sec17 inhibits fusion at an early stage. Thus, Vps33/HOPS promotes productive SNARE assembly in the presence of otherwise inhibitory Sec17. Once SNAREs are partially zipped, Sec17 promotes fusion in either the presence or absence of HOPS, but with faster kinetics when HOPS is absent, suggesting that ejection of the SM is a rate-limiting step.
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Affiliation(s)
- Matthew L Schwartz
- Department of Biochemistry, University of Washington School of Medicine, Seattle, United States
| | - Daniel P Nickerson
- Department of Biology, California State University, San Bernardino, United States
| | - Braden T Lobingier
- Department of Biochemistry, University of Washington School of Medicine, Seattle, United States
| | - Rachael L Plemel
- Department of Biochemistry, University of Washington School of Medicine, Seattle, United States
| | - Mengtong Duan
- Department of Biochemistry, University of Washington School of Medicine, Seattle, United States
| | - Cortney G Angers
- Department of Biochemistry, University of Washington School of Medicine, Seattle, United States
| | - Michael Zick
- Department of Biochemistry, Geisel School of Medicine at Dartmouth, Hanover, United States
| | - Alexey J Merz
- Department of Biochemistry, University of Washington School of Medicine, Seattle, United States.,Department of Physiology and Biophysics, University of Washington School of Medicine, Seattle, United States
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30
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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: 79] [Impact Index Per Article: 11.3] [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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31
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Oku M, Maeda Y, Kagohashi Y, Kondo T, Yamada M, Fujimoto T, Sakai Y. Evidence for ESCRT- and clathrin-dependent microautophagy. J Cell Biol 2017; 216:3263-3274. [PMID: 28838958 PMCID: PMC5626533 DOI: 10.1083/jcb.201611029] [Citation(s) in RCA: 115] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Revised: 04/27/2017] [Accepted: 07/24/2017] [Indexed: 12/20/2022] Open
Abstract
Microautophagy is a mode of autophagy in which the lysosomal or vacuolar membrane invaginates and engulfs target components. Oku et al. show that, upon a diauxic shift, yeast microautophagy involves recruitment of ESCRT proteins to the vacuolar membrane, including clathrin-interacting Vps27, and uptake of lipid droplets by the vacuole. Microautophagy refers to a mode of autophagy in which the lysosomal or vacuolar membrane invaginates and directly engulfs target components. The molecular machinery of membrane dynamics driving microautophagy is still elusive. Using immunochemical monitoring of yeast vacuolar transmembrane proteins, Vph1 and Pho8, fused to fluorescent proteins, we obtained evidence showing an induction of microautophagy after a diauxic shift in the yeast Saccharomyces cerevisiae. Components of the endosomal sorting complex required for transport machinery were found to be required for this process, and the gateway protein of the machinery, Vps27, was observed to change its localization onto the vacuolar membrane after a diauxic shift. We revealed the functional importance of Vps27’s interaction with clathrin in this microautophagy that also contributed to uptake of lipid droplets into the vacuole. This study sheds light on the molecular mechanism of microautophagy, which does not require the core Atg proteins.
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Affiliation(s)
- Masahide Oku
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | - Yuichiro Maeda
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | - Yoko Kagohashi
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | - Takeshi Kondo
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | - Mai Yamada
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | - Toyoshi Fujimoto
- Department of Anatomy and Molecular Cell Biology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Yasuyoshi Sakai
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kyoto, Japan .,Research Unit for Physiological Chemistry, Center for the Promotion of Interdisciplinary Education and Research, Kyoto University, Kyoto, Japan
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32
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Zhu L, Jorgensen JR, Li M, Chuang YS, Emr SD. ESCRTs function directly on the lysosome membrane to downregulate ubiquitinated lysosomal membrane proteins. eLife 2017; 6:e26403. [PMID: 28661397 PMCID: PMC5507667 DOI: 10.7554/elife.26403] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Accepted: 06/23/2017] [Indexed: 11/23/2022] Open
Abstract
The lysosome plays an important role in maintaining cellular nutrient homeostasis. Regulation of nutrient storage can occur by the ubiquitination of certain transporters that are then sorted into the lysosome lumen for degradation. To better understand the underlying mechanism of this process, we performed genetic screens to identify components of the sorting machinery required for vacuole membrane protein degradation. These screens uncovered genes that encode a ubiquitin ligase complex, components of the PtdIns 3-kinase complex, and the ESCRT machinery. We developed a novel ubiquitination system, Rapamycin-Induced Degradation (RapiDeg), to test the sorting defects caused by these mutants. These tests revealed that ubiquitinated vacuole membrane proteins recruit ESCRTs to the vacuole surface, where they mediate cargo sorting and direct cargo delivery into the vacuole lumen. Our findings demonstrate that the ESCRTs can function at both the late endosome and the vacuole membrane to mediate cargo sorting and intra-luminal vesicle formation.
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Affiliation(s)
- Lu Zhu
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, United States
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, United States
| | - Jeff R Jorgensen
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, United States
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, United States
| | - Ming Li
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, United States
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, United States
| | - Ya-Shan Chuang
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, United States
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, United States
| | - Scott D Emr
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, United States
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33
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Davis S, Wang J, Ferro-Novick S. Crosstalk between the Secretory and Autophagy Pathways Regulates Autophagosome Formation. Dev Cell 2017; 41:23-32. [PMID: 28399396 DOI: 10.1016/j.devcel.2017.03.015] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2016] [Revised: 02/26/2017] [Accepted: 03/16/2017] [Indexed: 12/26/2022]
Abstract
The induction of autophagy by nutrient deprivation leads to a rapid increase in the formation of autophagosomes, unique organelles that replenish the cellular pool of nutrients by sequestering cytoplasmic material for degradation. The urgent need for membranes to form autophagosomes during starvation to maintain homeostasis leads to a dramatic rearrangement of intracellular membranes. Here we discuss recent findings that have begun to uncover how different parts of the secretory pathway directly and indirectly contribute to autophagosome formation during starvation.
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Affiliation(s)
- Saralin Davis
- Department of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, CA 92093-0668, USA
| | - Juan Wang
- Department of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, CA 92093-0668, USA
| | - Susan Ferro-Novick
- Department of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, CA 92093-0668, USA.
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34
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López-Berges MS, Arst HN, Pinar M, Peñalva MA. Genetic studies on the physiological role of CORVET in Aspergillus nidulans. FEMS Microbiol Lett 2017; 364:3095991. [PMID: 28379362 DOI: 10.1093/femsle/fnx065] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
CORVET and HOPS are protein complexes mediating the maturation of early endosomes (EEs) into late endosomes (LEs)/vacuoles. These hetero-hexamers share four 'core' components, Vps11, Vps16, Vps18 and Vps33, and differ in two specific subunits, CORVET Vps8 and Vps3 and HOPS Vps39 and Vps41. Whereas ablating HOPS-specific components has minor growth effects, ablating any CORVET constituent severely debilitates Aspergillus nidulans growth, buttressing previous work indicating that maturation of EEs into LEs is physiologically crucial. A genetic screen revealed that impairing the slt cation homeostasis pathway rescues the growth defect resulting from inactivation of the 'core' protein Vps33. Subsequent genetic analyses showed that the defect resulting from lack of any one of the five other CORVET components could similarly be rescued by sltAΔ eliminating the slt regulator SltA. Whereas double deletants lacking functionally non-equivalent components of the CORVET and HOPS complexes are rescued by sltAΔ, those lacking functionally equivalent components are not, suggesting that intermediate 'hybrid' complexes previously detected in yeast are physiologically relevant. vps3Δ, vps8Δ, vps39Δ and vps41Δ result in small vacuoles. This phenotype is remediable by sltAΔ in the case of CORVET-specific, but not in the case of HOPS-specific deletants, indicating that the slt- effect on vacuolar size necessitates HOPS.
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Affiliation(s)
- Manuel S López-Berges
- Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas CSIC, Ramiro de Maeztu 9, Madrid 28040, Spain
| | - Herbert N Arst
- Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas CSIC, Ramiro de Maeztu 9, Madrid 28040, Spain.,Section of Microbiology, Imperial College London, Flowers Building, Armstrong Road, London SW7 2AZ, UK
| | - Mario Pinar
- Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas CSIC, Ramiro de Maeztu 9, Madrid 28040, Spain
| | - Miguel A Peñalva
- Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas CSIC, Ramiro de Maeztu 9, Madrid 28040, Spain
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35
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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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36
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Hegedűs K, Takáts S, Boda A, Jipa A, Nagy P, Varga K, Kovács AL, Juhász G. The Ccz1-Mon1-Rab7 module and Rab5 control distinct steps of autophagy. Mol Biol Cell 2016; 27:3132-3142. [PMID: 27559127 PMCID: PMC5063620 DOI: 10.1091/mbc.e16-03-0205] [Citation(s) in RCA: 145] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Revised: 08/15/2016] [Accepted: 08/17/2016] [Indexed: 12/30/2022] Open
Abstract
The small GTPase Rab5 promotes recruitment of the Ccz1-Mon1 guanosine exchange complex to endosomes to activate Rab7, which facilitates endosome maturation and fusion with lysosomes. How these factors function during autophagy is incompletely understood. Here we show that autophagosomes accumulate due to impaired fusion with lysosomes upon loss of the Ccz1-Mon1-Rab7 module in starved Drosophila fat cells. In contrast, autophagosomes generated in Rab5-null mutant cells normally fuse with lysosomes during the starvation response. Consistent with that, Rab5 is dispensable for the Ccz1-Mon1-dependent recruitment of Rab7 to PI3P-positive autophagosomes, which are generated by the action of the Atg14-containing Vps34 PI3 kinase complex. Finally, we find that Rab5 is required for proper lysosomal function. Thus the Ccz1-Mon1-Rab7 module is required for autophagosome-lysosome fusion, whereas Rab5 loss interferes with a later step of autophagy: the breakdown of autophagic cargo within lysosomes.
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Affiliation(s)
- Krisztina Hegedűs
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest H-1117, Hungary
| | - Szabolcs Takáts
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest H-1117, Hungary
| | - Attila Boda
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest H-1117, Hungary
| | - András Jipa
- Institute of Genetics, Biological Research Centre, Szeged H-6726, Hungary
| | - Péter Nagy
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest H-1117, Hungary
| | - Kata Varga
- Institute of Genetics, Biological Research Centre, Szeged H-6726, Hungary
| | - Attila L Kovács
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest H-1117, Hungary
| | - Gábor Juhász
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest H-1117, Hungary Institute of Genetics, Biological Research Centre, Szeged H-6726, Hungary
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37
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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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38
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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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39
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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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40
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Homozygous mutation of VPS16 gene is responsible for an autosomal recessive adolescent-onset primary dystonia. Sci Rep 2016; 6:25834. [PMID: 27174565 PMCID: PMC4865952 DOI: 10.1038/srep25834] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Accepted: 04/22/2016] [Indexed: 02/07/2023] Open
Abstract
Dystonia is a neurological movement disorder that is clinically and genetically heterogeneous. Herein, we report the identification a novel homozygous missense mutation, c.156 C > A in VPS16, co-segregating with disease status in a Chinese consanguineous family with adolescent-onset primary dystonia by whole exome sequencing and homozygosity mapping. To assess the biological role of c.156 C > A homozygous mutation of VPS16, we generated mice with targeted mutation site of Vps16 through CRISPR-Cas9 genome-editing approach. Vps16 c.156 C > A homozygous mutant mice exhibited significantly impaired motor function, suggesting that VPS16 is a new causative gene for adolescent-onset primary dystonia.
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41
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Zhang J, Lachance V, Schaffner A, Li X, Fedick A, Kaye LE, Liao J, Rosenfeld J, Yachelevich N, Chu ML, Mitchell WG, Boles RG, Moran E, Tokita M, Gorman E, Bagley K, Zhang W, Xia F, Leduc M, Yang Y, Eng C, Wong LJ, Schiffmann R, Diaz GA, Kornreich R, Thummel R, Wasserstein M, Yue Z, Edelmann L. A Founder Mutation in VPS11 Causes an Autosomal Recessive Leukoencephalopathy Linked to Autophagic Defects. PLoS Genet 2016; 12:e1005848. [PMID: 27120463 PMCID: PMC4847778 DOI: 10.1371/journal.pgen.1005848] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Accepted: 01/15/2016] [Indexed: 11/24/2022] Open
Abstract
Genetic leukoencephalopathies (gLEs) are a group of heterogeneous disorders with white matter abnormalities affecting the central nervous system (CNS). The causative mutation in ~50% of gLEs is unknown. Using whole exome sequencing (WES), we identified homozygosity for a missense variant, VPS11: c.2536T>G (p.C846G), as the genetic cause of a leukoencephalopathy syndrome in five individuals from three unrelated Ashkenazi Jewish (AJ) families. All five patients exhibited highly concordant disease progression characterized by infantile onset leukoencephalopathy with brain white matter abnormalities, severe motor impairment, cortical blindness, intellectual disability, and seizures. The carrier frequency of the VPS11: c.2536T>G variant is 1:250 in the AJ population (n = 2,026). VPS11 protein is a core component of HOPS (homotypic fusion and protein sorting) and CORVET (class C core vacuole/endosome tethering) protein complexes involved in membrane trafficking and fusion of the lysosomes and endosomes. The cysteine 846 resides in an evolutionarily conserved cysteine-rich RING-H2 domain in carboxyl terminal regions of VPS11 proteins. Our data shows that the C846G mutation causes aberrant ubiquitination and accelerated turnover of VPS11 protein as well as compromised VPS11-VPS18 complex assembly, suggesting a loss of function in the mutant protein. Reduced VPS11 expression leads to an impaired autophagic activity in human cells. Importantly, zebrafish harboring a vps11 mutation with truncated RING-H2 domain demonstrated a significant reduction in CNS myelination following extensive neuronal death in the hindbrain and midbrain. Thus, our study reveals a defect in VPS11 as the underlying etiology for an autosomal recessive leukoencephalopathy disorder associated with a dysfunctional autophagy-lysosome trafficking pathway. Genetic leukoencephalopathies (gLEs) are a group of heterogeneous disorders with white matter abnormalities in the central nervous system (CNS). Patients affected with gLEs have brain white matter defects that can be seen on MRI and exhibit variable neurologic phenotypes including motor impairment, hypotonia, pyramidal dysfunction, dystonia and/or dyskinesias, ataxia, seizures, cortical blindness, optic atrophy, and impaired cognitive development. The exact etiology of half of gLEs is unknown. We studied three unrelated families affected with an undiagnosed gLE and discovered a homozygous germline mutation c.2536T>G in VPS11, a gene involved in membrane trafficking and fusion of lysosomes and endosomes, as a novel cause of a new gLE syndrome. The mutation in VPS11 results in protein instability and impaired protein complex assembly. In addition, we show that VPS11 is required for proper autophagic activities in human cells. Importantly, we characterized a zebrafish line carrying a vps11 mutation and confirmed its essential role in brain white matter development and neuron survival.
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Affiliation(s)
- Jinglan Zhang
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Véronik Lachance
- Department of Neurology, The Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Adam Schaffner
- Department of Neurology, The Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Xianting Li
- Department of Neurology, The Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Anastasia Fedick
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Lauren E. Kaye
- Departments of Anatomy/Cell Biology and Ophthalmology, Wayne State University School of Medicine, Detroit, Michigan, United States of America
| | - Jun Liao
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Jill Rosenfeld
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Naomi Yachelevich
- Clinical Genetics Services, New York University Hospitals Center, New York, New York, United States of America
| | - Mary-Lynn Chu
- Department of Neurology, New York University School of Medicine, New York, New York, United States of America
| | - Wendy G. Mitchell
- Neurology Division, Children's Hospital Los Angeles, Los Angeles, California, United States of America
| | - Richard G. Boles
- Division of Medical Genetics, Children's Hospital Los Angeles, Los Angeles, California, United States of America
- Courtagen Life Sciences, Woburn, Massachusetts, United States of America
| | - Ellen Moran
- Clinical Genetics Services, NYU Langone Hospital for Joint Diseases, New York, New York, United States of America
| | - Mari Tokita
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Elizabeth Gorman
- Baylor Miraca Genetics Laboratories, Houston, Texas, United States of America
| | - Kaytee Bagley
- Baylor Miraca Genetics Laboratories, Houston, Texas, United States of America
| | - Wei Zhang
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Fan Xia
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Magalie Leduc
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Yaping Yang
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Christine Eng
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Lee-Jun Wong
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Raphael Schiffmann
- Institute of Metabolic Disease, Baylor Research Institute, Dallas, Texas, United States of America
| | - George A. Diaz
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Ruth Kornreich
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Ryan Thummel
- Departments of Anatomy/Cell Biology and Ophthalmology, Wayne State University School of Medicine, Detroit, Michigan, United States of America
| | - Melissa Wasserstein
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Zhenyu Yue
- Department of Neurology, The Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
- * E-mail: (ZY); (LE)
| | - Lisa Edelmann
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
- * E-mail: (ZY); (LE)
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Kaur G, Subramanian S. A novel RING finger in the C-terminal domain of the coatomer protein α-COP. Biol Direct 2015; 10:70. [PMID: 26666296 PMCID: PMC4678705 DOI: 10.1186/s13062-015-0099-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Accepted: 12/03/2015] [Indexed: 11/13/2022] Open
Abstract
The C-terminal domain of α-COP, an essential subunit of the COPI coatomer complex, is composed of an all α-helical region and a small β-sheet domain. We show that this β-sheet domain is a Really Interesting New Gene (RING)-like treble clef zinc finger. The zinc-binding residues are substituted by other aminoacids in many homologs including the structurally-characterized proteins from Saccharomyces cerevisiae and Bos taurus. This RING-like domain is possibly related to those of other vesicle membrane-associated complexes, such as CORVET, HOPS and SEA, and likely mediates interactions with Dsl1p and assist in coat oligomerization.
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Affiliation(s)
- Gurmeet Kaur
- CSIR-Institute of Microbial Technology (IMTECH), Sector 39-A, Chandigarh, 160036, India.
| | - Srikrishna Subramanian
- CSIR-Institute of Microbial Technology (IMTECH), Sector 39-A, Chandigarh, 160036, India.
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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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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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45
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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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Fernandes AC, Uytterhoeven V, Kuenen S, Wang YC, Slabbaert JR, Swerts J, Kasprowicz J, Aerts S, Verstreken P. Reduced synaptic vesicle protein degradation at lysosomes curbs TBC1D24/sky-induced neurodegeneration. ACTA ACUST UNITED AC 2015; 207:453-62. [PMID: 25422373 PMCID: PMC4242831 DOI: 10.1083/jcb.201406026] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Synaptic demise and accumulation of dysfunctional proteins are thought of as common features in neurodegeneration. However, the mechanisms by which synaptic proteins turn over remain elusive. In this paper, we study Drosophila melanogaster lacking active TBC1D24/Skywalker (Sky), a protein that in humans causes severe neurodegeneration, epilepsy, and DOOR (deafness, onychdystrophy, osteodystrophy, and mental retardation) syndrome, and identify endosome-to-lysosome trafficking as a mechanism for degradation of synaptic vesicle-associated proteins. In fly sky mutants, synaptic vesicles traveled excessively to endosomes. Using chimeric fluorescent timers, we show that synaptic vesicle-associated proteins were younger on average, suggesting that older proteins are more efficiently degraded. Using a genetic screen, we find that reducing endosomal-to-lysosomal trafficking, controlled by the homotypic fusion and vacuole protein sorting (HOPS) complex, rescued the neurotransmission and neurodegeneration defects in sky mutants. Consistently, synaptic vesicle proteins were older in HOPS complex mutants, and these mutants also showed reduced neurotransmission. Our findings define a mechanism in which synaptic transmission is facilitated by efficient protein turnover at lysosomes and identify a potential strategy to suppress defects arising from TBC1D24 mutations in humans.
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Affiliation(s)
- Ana Clara Fernandes
- VIB Center for the Biology of Disease and Center for Human Genetics Laboratory of Neuronal Communication, KU Leuven, 3000 Leuven, Belgium VIB Center for the Biology of Disease and Center for Human Genetics Laboratory of Neuronal Communication, KU Leuven, 3000 Leuven, Belgium
| | - Valerie Uytterhoeven
- VIB Center for the Biology of Disease and Center for Human Genetics Laboratory of Neuronal Communication, KU Leuven, 3000 Leuven, Belgium VIB Center for the Biology of Disease and Center for Human Genetics Laboratory of Neuronal Communication, KU Leuven, 3000 Leuven, Belgium
| | - Sabine Kuenen
- VIB Center for the Biology of Disease and Center for Human Genetics Laboratory of Neuronal Communication, KU Leuven, 3000 Leuven, Belgium VIB Center for the Biology of Disease and Center for Human Genetics Laboratory of Neuronal Communication, KU Leuven, 3000 Leuven, Belgium
| | - Yu-Chun Wang
- VIB Center for the Biology of Disease and Center for Human Genetics Laboratory of Neuronal Communication, KU Leuven, 3000 Leuven, Belgium VIB Center for the Biology of Disease and Center for Human Genetics Laboratory of Neuronal Communication, KU Leuven, 3000 Leuven, Belgium
| | - Jan R Slabbaert
- VIB Center for the Biology of Disease and Center for Human Genetics Laboratory of Neuronal Communication, KU Leuven, 3000 Leuven, Belgium VIB Center for the Biology of Disease and Center for Human Genetics Laboratory of Neuronal Communication, KU Leuven, 3000 Leuven, Belgium
| | - Jef Swerts
- VIB Center for the Biology of Disease and Center for Human Genetics Laboratory of Neuronal Communication, KU Leuven, 3000 Leuven, Belgium VIB Center for the Biology of Disease and Center for Human Genetics Laboratory of Neuronal Communication, KU Leuven, 3000 Leuven, Belgium
| | - Jaroslaw Kasprowicz
- VIB Center for the Biology of Disease and Center for Human Genetics Laboratory of Neuronal Communication, KU Leuven, 3000 Leuven, Belgium VIB Center for the Biology of Disease and Center for Human Genetics Laboratory of Neuronal Communication, KU Leuven, 3000 Leuven, Belgium
| | - Stein Aerts
- VIB Center for the Biology of Disease and Center for Human Genetics Laboratory of Neuronal Communication, KU Leuven, 3000 Leuven, Belgium
| | - Patrik Verstreken
- VIB Center for the Biology of Disease and Center for Human Genetics Laboratory of Neuronal Communication, KU Leuven, 3000 Leuven, Belgium VIB Center for the Biology of Disease and Center for Human Genetics Laboratory of Neuronal Communication, KU Leuven, 3000 Leuven, Belgium
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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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Zirin J, Nieuwenhuis J, Samsonova A, Tao R, Perrimon N. Regulators of autophagosome formation in Drosophila muscles. PLoS Genet 2015; 11:e1005006. [PMID: 25692684 PMCID: PMC4334200 DOI: 10.1371/journal.pgen.1005006] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2013] [Accepted: 01/15/2015] [Indexed: 01/08/2023] Open
Abstract
Given the diversity of autophagy targets and regulation, it is important to characterize autophagy in various cell types and conditions. We used a primary myocyte cell culture system to assay the role of putative autophagy regulators in the specific context of skeletal muscle. By treating the cultures with rapamycin (Rap) and chloroquine (CQ) we induced an autophagic response, fully suppressible by knockdown of core ATG genes. We screened D. melanogaster orthologs of a previously reported mammalian autophagy protein-protein interaction network, identifying several proteins required for autophagosome formation in muscle cells, including orthologs of the Rab regulators RabGap1 and Rab3Gap1. The screen also highlighted the critical roles of the proteasome and glycogen metabolism in regulating autophagy. Specifically, sustained proteasome inhibition inhibited autophagosome formation both in primary culture and larval skeletal muscle, even though autophagy normally acts to suppress ubiquitin aggregate formation in these tissues. In addition, analyses of glycogen metabolic genes in both primary cultured and larval muscles indicated that glycogen storage enhances the autophagic response to starvation, an important insight given the link between glycogen storage disorders, autophagy, and muscle function. Since the identification of the core autophagy genes in yeast, tissue culture cell lines have been the primary tool to evaluate the role and regulation of autophagy in higher organisms. However, since autophagy is a tissue-specific, context dependent process, stable cell lines can only give a limited view of the autophagic process. Here, we focus on the role of putative autophagy regulators in the specific context of the skeletal muscle, which has one of the most robust autophagy responses in mammals. We describe a fruitfly model of autophagy for skeletal muscles that integrates rapid genetic screening in primary cultured cells with robust in vivo validation in the larval muscle. We screened a set of genes previously linked to the autophagy pathway in humans, and identified both positive and negative regulators of autophagy. Our observation that genes involved in sugar metabolism impact muscle autophagy has important implications for both skeletal and cardiac myopathies associated with aberrant sugar storage. Surprisingly, we found that the proteasome is required to maintain autophagy in the muscle, suggesting that therapeutic treatments aiming to induce autophagy by proteasome inhibition must be carefully calibrated to ensure that the opposite phenotype does not occur.
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Affiliation(s)
- Jonathan Zirin
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, United States of America
- * E-mail: (JZ); (NP)
| | - Joppe Nieuwenhuis
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Anastasia Samsonova
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Rong Tao
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Norbert Perrimon
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, United States of America
- Howard Hughes Medical Institute, Harvard Medical School, Boston, Massachusetts, United States of America
- * E-mail: (JZ); (NP)
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49
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Li M, Rong Y, Chuang YS, Peng D, Emr SD. Ubiquitin-dependent lysosomal membrane protein sorting and degradation. Mol Cell 2015; 57:467-78. [PMID: 25620559 DOI: 10.1016/j.molcel.2014.12.012] [Citation(s) in RCA: 78] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2014] [Revised: 10/22/2014] [Accepted: 12/03/2014] [Indexed: 12/17/2022]
Abstract
As an essential organelle in the cell, the lysosome is responsible for digestion and recycling of intracellular components, storage of nutrients, and pH homeostasis. The lysosome is enclosed by a special membrane to maintain its integrity, and nutrients are transported across the membrane by numerous transporters. Despite their importance in maintaining nutrient homeostasis and regulating signaling pathways, little is known about how lysosomal membrane protein lifetimes are regulated. We identified a yeast vacuolar amino acid transporter, Ypq1, that is selectively sorted and degraded in the vacuolar lumen following lysine withdrawal. This selective degradation process requires a vacuole anchored ubiquitin ligase (VAcUL-1) complex composed of Rsp5 and Ssh4. We propose that after ubiquitination, Ypq1 is selectively sorted into an intermediate compartment. The ESCRT machinery is then recruited to sort the ubiquitinated Ypq1 into intraluminal vesicles (ILVs). Finally, the compartment fuses with the vacuole and delivers ILVs into the lumen for degradation.
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Affiliation(s)
- Ming Li
- Weill Institute for Cell and Molecular Biology and Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, 14853, USA
| | - Yueguang Rong
- Weill Institute for Cell and Molecular Biology and Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, 14853, USA
| | - Ya-Shan Chuang
- Weill Institute for Cell and Molecular Biology and Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, 14853, USA
| | - Dan Peng
- Weill Institute for Cell and Molecular Biology and Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, 14853, USA
| | - Scott D Emr
- Weill Institute for Cell and Molecular Biology and Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, 14853, USA.
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50
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Asrat S, de Jesús DA, Hempstead AD, Ramabhadran V, Isberg RR. Bacterial Pathogen Manipulation of Host Membrane Trafficking. Annu Rev Cell Dev Biol 2014; 30:79-109. [DOI: 10.1146/annurev-cellbio-100913-013439] [Citation(s) in RCA: 98] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Seblewongel Asrat
- Howard Hughes Medical Institute,
- Department of Molecular Biology and Microbiology, and
- Graduate Program in Molecular Microbiology, Sackler School of Graduate Biomedical Science, Tufts University School of Medicine, Boston, Massachusetts, 02111; , , , ,
| | - Dennise A. de Jesús
- Department of Molecular Biology and Microbiology, and
- Graduate Program in Molecular Microbiology, Sackler School of Graduate Biomedical Science, Tufts University School of Medicine, Boston, Massachusetts, 02111; , , , ,
| | - Andrew D. Hempstead
- Department of Molecular Biology and Microbiology, and
- Graduate Program in Molecular Microbiology, Sackler School of Graduate Biomedical Science, Tufts University School of Medicine, Boston, Massachusetts, 02111; , , , ,
| | - Vinay Ramabhadran
- Howard Hughes Medical Institute,
- Department of Molecular Biology and Microbiology, and
| | - Ralph R. Isberg
- Howard Hughes Medical Institute,
- Department of Molecular Biology and Microbiology, and
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