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Schleinitz A, Pöttgen LA, Keren-Kaplan T, Pu J, Saftig P, Bonifacino JS, Haas A, Jeschke A. Consecutive functions of small GTPases guide HOPS-mediated tethering of late endosomes and lysosomes. Cell Rep 2023; 42:111969. [PMID: 36640308 PMCID: PMC10018218 DOI: 10.1016/j.celrep.2022.111969] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 10/12/2022] [Accepted: 12/20/2022] [Indexed: 01/06/2023] Open
Abstract
The transfer of endocytosed cargoes to lysosomes (LYSs) requires HOPS, a multiprotein complex that tethers late endosomes (LEs) to LYSs before fusion. Many proteins interact with HOPS on LEs/LYSs. However, it is not clear whether these HOPS interactors localize to LEs or LYSs or how they participate in tethering. Here, we biochemically characterized endosomes purified from untreated or experimentally manipulated cells to put HOPS and interacting proteins in order and to establish their functional interdependence. Our results assign Rab2a and Rab7 to LEs and Arl8 and BORC to LYSs and show that HOPS drives LE-LYS fusion by bridging late endosomal Rab2a with lysosomal BORC-anchored Arl8. We further show that Rab7 is absent from sites of HOPS-dependent tethering but promotes fusion by moving LEs toward LYSs via dynein. Thus, our study identifies the topology of the machinery for LE-LYS tethering and elucidates the role of different small GTPases in the process.
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Affiliation(s)
| | | | - Tal Keren-Kaplan
- Neurosciences and Cellular and Structural Biology Division, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Jing Pu
- Department of Molecular Genetics and Microbiology, and Autophagy, Inflammation, and Metabolism, Center of Biomedical Research Excellence, University of New Mexico, Albuquerque, NM 87131, USA
| | - Paul Saftig
- Biochemical Institute, University of Kiel, 24118 Kiel, Germany
| | - Juan S Bonifacino
- Neurosciences and Cellular and Structural Biology Division, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Albert Haas
- Cell Biology Institute, University of Bonn, 53121 Bonn, Germany.
| | - Andreas Jeschke
- Cell Biology Institute, University of Bonn, 53121 Bonn, Germany.
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2
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Jin Y, Deng Z, Zhu T. Membrane protein trafficking in the anti-tumor immune response: work of endosomal-lysosomal system. Cancer Cell Int 2022; 22:413. [PMID: 36528587 PMCID: PMC9759898 DOI: 10.1186/s12935-022-02805-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2022] [Accepted: 11/24/2022] [Indexed: 12/23/2022] Open
Abstract
Immunotherapy has changed the treatment landscape for multiple cancer types. In the recent decade, great progress has been made in immunotherapy, including immune checkpoint inhibitors, adoptive T-cell therapy, and cancer vaccines. ICIs work by reversing tumor-induced immunosuppression, resulting in robust activation of the immune system and lasting immune responses. Whereas, their clinical use faces several challenges, especially the low response rate in most patients. As an increasing number of studies have focused on membrane immune checkpoint protein trafficking and degradation, which interferes with response to immunotherapy, it is necessary to summarize the mechanism regulating those transmembrane domain proteins translocated into the cytoplasm and degraded via lysosome. In addition, other immune-related transmembrane domain proteins such as T-cell receptor and major histocompatibility are associated with neoantigen presentation. The endosomal-lysosomal system can also regulate TCR and neoantigen-MHC complexes on the membrane to affect the efficacy of adoptive T-cell therapy and cancer vaccines. In conclusion, we discuss the process of surface delivery, internalization, recycling, and degradation of immune checkpoint proteins, TCR, and neoantigen-MHC complexes on the endosomal-lysosomal system in biology for optimizing cancer immunotherapy.
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Affiliation(s)
- Yan Jin
- grid.412632.00000 0004 1758 2270Cancer Center, Renmin Hospital of Wuhan University, Wuhan, 430060 China
| | - Zhifeng Deng
- grid.412632.00000 0004 1758 2270Department of Otolaryngology Head and Neck Surgery, Renmin Hospital of Wuhan University, Wuhan, 430060 China
| | - Ting Zhu
- grid.412632.00000 0004 1758 2270Department of Otolaryngology Head and Neck Surgery, Renmin Hospital of Wuhan University, Wuhan, 430060 China
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3
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Prikas E, Paric E, Asih PR, Stefanoska K, Stefen H, Fath T, Poljak A, Ittner A. Tau target identification reveals NSF-dependent effects on AMPA receptor trafficking and memory formation. EMBO J 2022; 41:e10242. [PMID: 35993331 PMCID: PMC9475529 DOI: 10.15252/embj.2021110242] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2021] [Revised: 07/03/2022] [Accepted: 07/18/2022] [Indexed: 11/09/2022] Open
Abstract
Microtubule-associated protein tau is a central factor in Alzheimer's disease and other tauopathies. However, the physiological functions of tau are unclear. Here, we used proximity-labelling proteomics to chart tau interactomes in primary neurons and mouse brains in vivo. Tau interactors map onto pathways of cytoskeletal, synaptic vesicle and postsynaptic receptor regulation and show significant enrichment for Parkinson's, Alzheimer's and prion disease. We find that tau interacts with and dose-dependently reduces the activity of N-ethylmaleimide sensitive fusion protein (NSF), a vesicular ATPase essential for AMPA-type glutamate receptor (AMPAR) trafficking. Tau-deficient (tau-/- ) neurons showed mislocalised expression of NSF and enhanced synaptic AMPAR surface levels, reversible through the expression of human tau or inhibition of NSF. Consequently, enhanced AMPAR-mediated associative and object recognition memory in tau-/- mice is suppressed by both hippocampal tau and infusion with an NSF-inhibiting peptide. Pathologic mutant tau from mouse models or Alzheimer's disease significantly enhances NSF inhibition. Our results map neuronal tau interactomes and delineate a functional link of tau with NSF in plasticity-associated AMPAR-trafficking and memory.
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Affiliation(s)
- Emmanuel Prikas
- Flinders Health & Medical Research Institute, College of Medicine and Public HealthFlinders UniversityAdelaideSAAustralia
| | - Esmeralda Paric
- Dementia Research Centre, Macquarie Medical School, Faculty of Medicine, Health and Human SciencesMacquarie UniversitySydneyNSWAustralia
| | - Prita R Asih
- Flinders Health & Medical Research Institute, College of Medicine and Public HealthFlinders UniversityAdelaideSAAustralia
| | - Kristie Stefanoska
- Flinders Health & Medical Research Institute, College of Medicine and Public HealthFlinders UniversityAdelaideSAAustralia
| | - Holly Stefen
- Dementia Research Centre, Macquarie Medical School, Faculty of Medicine, Health and Human SciencesMacquarie UniversitySydneyNSWAustralia
| | - Thomas Fath
- Dementia Research Centre, Macquarie Medical School, Faculty of Medicine, Health and Human SciencesMacquarie UniversitySydneyNSWAustralia
| | - Anne Poljak
- Mark Wainwright Analytical CentreUniversity of New South WalesSydneyNSWAustralia
| | - Arne Ittner
- Flinders Health & Medical Research Institute, College of Medicine and Public HealthFlinders UniversityAdelaideSAAustralia
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4
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Zhou HL, Premont RT, Stamler JS. The manifold roles of protein S-nitrosylation in the life of insulin. Nat Rev Endocrinol 2022; 18:111-128. [PMID: 34789923 PMCID: PMC8889587 DOI: 10.1038/s41574-021-00583-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 10/08/2021] [Indexed: 02/04/2023]
Abstract
Insulin, which is released by pancreatic islet β-cells in response to elevated levels of glucose in the blood, is a critical regulator of metabolism. Insulin triggers the uptake of glucose and fatty acids into the liver, adipose tissue and muscle, and promotes the storage of these nutrients in the form of glycogen and lipids. Dysregulation of insulin synthesis, secretion, transport, degradation or signal transduction all cause failure to take up and store nutrients, resulting in type 1 diabetes mellitus, type 2 diabetes mellitus and metabolic dysfunction. In this Review, we make the case that insulin signalling is intimately coupled to protein S-nitrosylation, in which nitric oxide groups are conjugated to cysteine thiols to form S-nitrosothiols, within effectors of insulin action. We discuss the role of S-nitrosylation in the life cycle of insulin, from its synthesis and secretion in pancreatic β-cells, to its signalling and degradation in target tissues. Finally, we consider how aberrant S-nitrosylation contributes to metabolic diseases, including the roles of human genetic mutations and cellular events that alter S-nitrosylation of insulin-regulating proteins. Given the growing influence of S-nitrosylation in cellular metabolism, the field of metabolic signalling could benefit from renewed focus on S-nitrosylation in type 2 diabetes mellitus and insulin-related disorders.
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Affiliation(s)
- Hua-Lin Zhou
- Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, OH, USA
- Institute for Transformative Molecular Medicine, Case Western Reserve University School of Medicine, Cleveland, OH, USA
- Harrington Discovery Institute, University Hospitals Cleveland Medical Center, Cleveland, OH, USA
| | - Richard T Premont
- Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, OH, USA
- Institute for Transformative Molecular Medicine, Case Western Reserve University School of Medicine, Cleveland, OH, USA
- Harrington Discovery Institute, University Hospitals Cleveland Medical Center, Cleveland, OH, USA
| | - Jonathan S Stamler
- Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, OH, USA.
- Institute for Transformative Molecular Medicine, Case Western Reserve University School of Medicine, Cleveland, OH, USA.
- Harrington Discovery Institute, University Hospitals Cleveland Medical Center, Cleveland, OH, USA.
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Extreme parsimony in ATP consumption by 20S complexes in the global disassembly of single SNARE complexes. Nat Commun 2021; 12:3206. [PMID: 34050166 PMCID: PMC8163800 DOI: 10.1038/s41467-021-23530-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Accepted: 04/30/2021] [Indexed: 11/08/2022] Open
Abstract
Fueled by ATP hydrolysis in N-ethylmaleimide sensitive factor (NSF), the 20S complex disassembles rigid SNARE (soluble NSF attachment protein receptor) complexes in single unraveling step. This global disassembly distinguishes NSF from other molecular motors that make incremental and processive motions, but the molecular underpinnings of its remarkable energy efficiency remain largely unknown. Using multiple single-molecule methods, we found remarkable cooperativity in mechanical connection between NSF and the SNARE complex, which prevents dysfunctional 20S complexes that consume ATP without productive disassembly. We also constructed ATP hydrolysis cycle of the 20S complex, in which NSF largely shows randomness in ATP binding but switches to perfect ATP hydrolysis synchronization to induce global SNARE disassembly, minimizing ATP hydrolysis by non-20S complex-forming NSF molecules. These two mechanisms work in concert to concentrate ATP consumption into functional 20S complexes, suggesting evolutionary adaptations by the 20S complex to the energetically expensive mechanical task of SNARE complex disassembly. Fueled by ATP hydrolysis in N-ethylmaleimide sensitive factor (NSF), the 20S complex disassembles SNARE complexes in a single unravelling step. Here authors use single-molecule methods to show cooperativity between the NSF and SNARE complex, which prevents ATP consumption without productive disassembly.
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Tang LP, Yang Y, Wang H, Li L, Liu L, Liu Y, Yuan J, Zhao XY, Palme K, Su YH, Li X. AtNSF regulates leaf serration by modulating intracellular trafficking of PIN1 in Arabidopsis thaliana. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2020; 63:737-755. [PMID: 33289329 PMCID: PMC8151873 DOI: 10.1111/jipb.13043] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 11/30/2020] [Indexed: 06/03/2023]
Abstract
In eukaryotes, N-ethylmaleimide-sensitive factor (NSF) is a conserved AAA+ ATPase and a key component of the membrane trafficking machinery that promotes the fusion of secretory vesicles with target membranes. Here, we demonstrate that the Arabidopsis thaliana genome contains a single copy of NSF, AtNSF, which plays an essential role in the regulation of leaf serration. The AtNSF knock-down mutant, atnsf-1, exhibited more serrations in the leaf margin. Moreover, polar localization of the PIN-FORMED1 (PIN1) auxin efflux transporter was diffuse around the margins of atnsf-1 leaves and root growth was inhibited in the atnsf-1 mutant. More PIN1-GFP accumulated in the intracellular compartments of atnsf-1 plants, suggesting that AtNSF is required for intracellular trafficking of PIN between the endosome and plasma membrane. Furthermore, the serration phenotype was suppressed in the atnsf-1 pin1-8 double mutant, suggesting that AtNSF is required for PIN1-mediated polar auxin transport to regulate leaf serration. The CUP-SHAPED COTYLEDON2 (CUC2) transcription factor gene is up-regulated in atnsf-1 plants and the cuc2-3 single mutant exhibits smooth leaf margins, demonstrating that AtNSF also functions in the CUC2 pathway. Our results reveal that AtNSF regulates the PIN1-generated auxin maxima with a CUC2-mediated feedback loop to control leaf serration. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Li Ping Tang
- State Key Laboratory of Crop Biology, College of Life SciencesShandong Agricultural UniversityTai'an271018China
- Sino‐German Joint Research Center on Agricultural Biology, College of Life SciencesShandong Agricultural UniversityTai'an271018China
| | - Yi Yang
- State Key Laboratory of Crop Biology, College of Life SciencesShandong Agricultural UniversityTai'an271018China
- Sino‐German Joint Research Center on Agricultural Biology, College of Life SciencesShandong Agricultural UniversityTai'an271018China
| | - Hui Wang
- Institute of Biology II/Molecular Plant Physiology, Faculty of BiologyAlbert‐Ludwigs‐University of FreiburgSchänzlestrasse 1,FreiburgD‐79104Germany
| | - Lixin Li
- Key Laboratory of Saline‐alkali Vegetation Ecology Restoration, Ministry of Education, Alkali Soil Natural Environmental Science CenterNortheast Forestry UniversityHarbin150040China
| | - Le Liu
- Institute of Biology II/Molecular Plant Physiology, Faculty of BiologyAlbert‐Ludwigs‐University of FreiburgSchänzlestrasse 1,FreiburgD‐79104Germany
| | - Yu Liu
- State Key Laboratory of Crop Biology, College of Life SciencesShandong Agricultural UniversityTai'an271018China
- Sino‐German Joint Research Center on Agricultural Biology, College of Life SciencesShandong Agricultural UniversityTai'an271018China
| | - Jinfeng Yuan
- State Key Laboratory of Crop Biology, College of Life SciencesShandong Agricultural UniversityTai'an271018China
- Sino‐German Joint Research Center on Agricultural Biology, College of Life SciencesShandong Agricultural UniversityTai'an271018China
| | - Xiang Yu Zhao
- State Key Laboratory of Crop Biology, College of Life SciencesShandong Agricultural UniversityTai'an271018China
- Sino‐German Joint Research Center on Agricultural Biology, College of Life SciencesShandong Agricultural UniversityTai'an271018China
| | - Klaus Palme
- Sino‐German Joint Research Center on Agricultural Biology, College of Life SciencesShandong Agricultural UniversityTai'an271018China
- Institute of Biology II/Molecular Plant Physiology, Faculty of BiologyAlbert‐Ludwigs‐University of FreiburgSchänzlestrasse 1,FreiburgD‐79104Germany
- BIOSS Centre for Biological Signalling StudiesAlbert‐Ludwigs‐University Freiburg, SignalhausSchänzlestr. 18,FreiburgD‐79104Germany
- Center for Biological Systems Analysis (ZBSA)Albert‐Ludwigs‐University FreiburgFreiburgD‐79104Germany
| | - Ying Hua Su
- State Key Laboratory of Crop Biology, College of Life SciencesShandong Agricultural UniversityTai'an271018China
- Sino‐German Joint Research Center on Agricultural Biology, College of Life SciencesShandong Agricultural UniversityTai'an271018China
| | - Xugang Li
- State Key Laboratory of Crop Biology, College of Life SciencesShandong Agricultural UniversityTai'an271018China
- Sino‐German Joint Research Center on Agricultural Biology, College of Life SciencesShandong Agricultural UniversityTai'an271018China
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7
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López-Alonso M, Miranda M. Copper Supplementation, A Challenge in Cattle. Animals (Basel) 2020; 10:ani10101890. [PMID: 33076570 PMCID: PMC7602799 DOI: 10.3390/ani10101890] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 09/23/2020] [Accepted: 10/09/2020] [Indexed: 12/16/2022] Open
Abstract
Ensuring adequate copper supplementation in ruminants is a challenging task due to the complexity of copper metabolism in these animals. The three-way interaction between copper, molybdenum and sulphur (Cu-Mo-S) in the rumen makes ruminants, particularly cattle, very susceptible to suffering from secondary copper deficiency. Paradoxically, excessive copper storage in the liver to prevent deficiency becomes a hazard when ruminants are fed copper-supplemented diets even slightly above requirements. While cattle were traditionally thought to be relatively tolerant of copper accumulation, and reports of copper poisoning were until recently somewhat rare, in recent years an increased number of episodes/outbreaks of copper toxicity in cattle, particularly in dairy cattle, have been reported worldwide. The growing number of lethal cases reported seems to indicate that copper intoxication is spreading silently in dairy herds, urging the development of strategies to monitor herd copper status and improve farmers' awareness of copper toxicity. In fact, monitoring studies carried out on numerous samples collected from culled animals in slaughterhouses and/or diagnostic laboratories have demonstrated that large numbers of animals have hepatic copper concentrations well above adequate levels in many different countries. These trends are undoubtedly due to copper supplementation aimed at preventing copper deficiency, as dietary copper intake from pasture alone is unlikely to cause such high levels of accumulation in liver tissue. The reasons behind the copper overfeeding in cattle are related both to a poor understanding of copper metabolism and the theory of "if adding a little produces a response, then adding a lot will produce a better response". Contrary to most trace elements, copper in ruminants has narrow margins of safety, which must also be formulated considering the concentrations of copper antagonists in the diet. This review paper aims to provide nutritionists/veterinary practitioners with the key points about copper metabolism in cattle to guarantee an adequate copper supply while preventing excessive hepatic copper loading, which requires à la carte copper supplementation for each herd.
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Affiliation(s)
- Marta López-Alonso
- Department of Animal Pathology, Faculty of Veterinary Medicine, Universidade de Santiago de Compostela, Campus Terra, 27002 Lugo, Spain;
| | - Marta Miranda
- Department of Anatomy, Animal Production and Clinical Veterinary Sciences, Faculty of Veterinary Medicine, Universidade de Santiago de Compostela, Campus Terra, 27002 Lugo, Spain
- Correspondence: ; Tel.: +34-982-822-615
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A Mechanistic Perspective on PEX1 and PEX6, Two AAA+ Proteins of the Peroxisomal Protein Import Machinery. Int J Mol Sci 2019; 20:ijms20215246. [PMID: 31652724 PMCID: PMC6862443 DOI: 10.3390/ijms20215246] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 10/18/2019] [Accepted: 10/21/2019] [Indexed: 12/11/2022] Open
Abstract
In contrast to many protein translocases that use ATP or GTP hydrolysis as the driving force to transport proteins across biological membranes, the peroxisomal matrix protein import machinery relies on a regulated self-assembly mechanism for this purpose and uses ATP hydrolysis only to reset its components. The ATP-dependent protein complex in charge of resetting this machinery—the Receptor Export Module (REM)—comprises two members of the “ATPases Associated with diverse cellular Activities” (AAA+) family, PEX1 and PEX6, and a membrane protein that anchors the ATPases to the organelle membrane. In recent years, a large amount of data on the structure/function of the REM complex has become available. Here, we discuss the main findings and their mechanistic implications.
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9
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Huang X, Sun S, Wang X, Fan F, Zhou Q, Lu S, Cao Y, Wang QW, Dong MQ, Yao J, Sui SF. Mechanistic insights into the SNARE complex disassembly. SCIENCE ADVANCES 2019; 5:eaau8164. [PMID: 30989110 PMCID: PMC6457932 DOI: 10.1126/sciadv.aau8164] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Accepted: 02/19/2019] [Indexed: 05/16/2023]
Abstract
NSF (N-ethylmaleimide-sensitive factor) and α-SNAP (α-soluble NSF attachment protein) bind to the SNARE (soluble NSF attachment protein receptor) complex, the minimum machinery to mediate membrane fusion, to form a 20S complex, which disassembles the SNARE complex for reuse. We report the cryo-EM structures of the α-SNAP-SNARE subcomplex and the NSF-D1D2 domain in the 20S complex at 3.9- and 3.7-Å resolutions, respectively. Combined with the biochemical and electrophysiological analyses, we find that α-SNAPs use R116 through electrostatic interactions and L197 through hydrophobic interactions to apply force mainly on two positions of the VAMP protein to execute disassembly process. Furthermore, we define the interaction between the amino terminus of the SNARE helical bundle and the pore loop of the NSF-D1 domain and demonstrate its essential role as a potential anchor for SNARE complex disassembly. Our studies provide a rotation model of α-SNAP-mediated disassembly of the SNARE complex.
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Affiliation(s)
- Xuan Huang
- State Key Laboratory of Membrane Biology, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Shan Sun
- State Key Laboratory of Membrane Biology, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Xiaojing Wang
- State Key Laboratory of Membrane Biology, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Fenghui Fan
- State Key Laboratory of Membrane Biology, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Qiang Zhou
- State Key Laboratory of Membrane Biology, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Shan Lu
- National Institute of Biological Sciences, Beijing 102206, China
| | - Yong Cao
- National Institute of Biological Sciences, Beijing 102206, China
| | - Qiu-Wen Wang
- State Key Laboratory of Membrane Biology, Tsinghua-Peking Joint Center for Life Sciences, IDG/McGovern Institute for Brain Research, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Meng-Qiu Dong
- National Institute of Biological Sciences, Beijing 102206, China
| | - Jun Yao
- State Key Laboratory of Membrane Biology, Tsinghua-Peking Joint Center for Life Sciences, IDG/McGovern Institute for Brain Research, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Sen-Fang Sui
- State Key Laboratory of Membrane Biology, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
- Corresponding author.
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Saadin A, Starz-Gaiano M. Cytokine exocytosis and JAK/STAT activation in the Drosophila ovary requires the vesicle trafficking regulator α-Snap. J Cell Sci 2018; 131:jcs217638. [PMID: 30404830 PMCID: PMC6288073 DOI: 10.1242/jcs.217638] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Accepted: 10/11/2018] [Indexed: 01/03/2023] Open
Abstract
How vesicle trafficking components actively contribute to regulation of paracrine signaling is unclear. We genetically uncovered a requirement for α-soluble NSF attachment protein (α-Snap) in the activation of the Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway during Drosophila egg development. α-Snap, a well-conserved vesicle trafficking regulator, mediates association of N-ethylmaleimide-sensitive factor (NSF) and SNAREs to promote vesicle fusion. Depletion of α-Snap or the SNARE family member Syntaxin1A in epithelia blocks polar cells maintenance and prevents specification of motile border cells. Blocking apoptosis rescues polar cell maintenance in α-Snap-depleted egg chambers, indicating that the lack of border cells in mutants is due to impaired signaling. Genetic experiments implicate α-Snap and NSF in secretion of a STAT-activating cytokine. Live imaging suggests that changes in intracellular Ca2+ are linked to this event. Our data suggest a cell-type specific requirement for particular vesicle trafficking components in regulated exocytosis during development. Given the central role for STAT signaling in immunity, this work may shed light on regulation of cytokine release in humans.
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Affiliation(s)
- Afsoon Saadin
- Department of Biological Sciences, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250, USA
| | - Michelle Starz-Gaiano
- Department of Biological Sciences, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250, USA
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11
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Roles of Cellular NSF Protein in Entry and Nuclear Egress of Budded Virions of Autographa californica Multiple Nucleopolyhedrovirus. J Virol 2017; 91:JVI.01111-17. [PMID: 28747507 DOI: 10.1128/jvi.01111-17] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2017] [Accepted: 07/20/2017] [Indexed: 02/03/2023] Open
Abstract
In eukaryotic cells, the soluble N-ethylmaleimide-sensitive factor (NSF) attachment protein receptor (SNARE) proteins comprise the minimal machinery that triggers fusion of transport vesicles with their target membranes. Comparative studies revealed that genes encoding the components of the SNARE system are highly conserved in yeast, insect, and human genomes. Upon infection of insect cells by the virus Autographa californica multiple nucleopolyhedrovirus (AcMNPV), the transcript levels of most SNARE genes initially were upregulated. We found that overexpression of dominant-negative (DN) forms of NSF or knockdown of the expression of NSF, the key regulator of the SNARE system, significantly affected infectious AcMNPV production. In cells expressing DN NSF, entering virions were trapped in the cytoplasm or transported to the nucleus with low efficiency. The presence of DN NSF also moderately reduced trafficking of the viral envelope glycoprotein GP64 to the plasma membrane but dramatically inhibited production of infectious budded virions (BV). Transmission electron microscopy analysis of infections in cells expressing DN NSF revealed that progeny nucleocapsids were retained in a perinuclear space surrounded by inner and outer nuclear membranes. Several baculovirus conserved (core) proteins (Ac76, Ac78, GP41, Ac93, and Ac103) that are important for infectious budded virion production were found to associate with NSF, and NSF was detected within the assembled BV. Together, these data indicate that the cellular SNARE system is involved in AcMNPV infection and that NSF is required for efficient entry and nuclear egress of budded virions of AcMNPV.IMPORTANCE Little is known regarding the complex interplay between cellular factors and baculoviruses during viral entry and egress. Here, we examined the cellular SNARE system, which mediates the fusion of vesicles in healthy cells, and its relation to baculovirus infection. Using a DN approach and RNA interference knockdown, we demonstrated that a general disruption of the SNARE machinery significantly inhibited the production of infectious BV of AcMNPV. The presence of a DN NSF protein resulted in low-efficiency entry of BV and the retention of progeny nucleocapsids in the perinuclear space during egress. Combined with these effects, we also found that several conserved (core) baculovirus proteins closely associate with NSF, and these results suggest their involvement in the egress of BV. Our findings are the first to demonstrate that the SNARE system is required for efficient entry of BV and nuclear egress of progeny nucleocapsids of baculoviruses.
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12
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Duran EC, Weaver CL, Lucius AL. Comparative Analysis of the Structure and Function of AAA+ Motors ClpA, ClpB, and Hsp104: Common Threads and Disparate Functions. Front Mol Biosci 2017; 4:54. [PMID: 28824920 PMCID: PMC5540906 DOI: 10.3389/fmolb.2017.00054] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Accepted: 07/13/2017] [Indexed: 11/25/2022] Open
Abstract
Cellular proteostasis involves not only the expression of proteins in response to environmental needs, but also the timely repair or removal of damaged or unneeded proteins. AAA+ motor proteins are critically involved in these pathways. Here, we review the structure and function of AAA+ proteins ClpA, ClpB, and Hsp104. ClpB and Hsp104 rescue damaged proteins from toxic aggregates and do not partner with any protease. ClpA functions as the regulatory component of the ATP dependent protease complex ClpAP, and also remodels inactive RepA dimers into active monomers in the absence of the protease. Because ClpA functions both with and without a proteolytic component, it is an ideal system for developing strategies that address one of the major challenges in the study of protein remodeling machines: how do we observe a reaction in which the substrate protein does not undergo covalent modification? Here, we review experimental designs developed for the examination of polypeptide translocation catalyzed by the AAA+ motors in the absence of proteolytic degradation. We propose that transient state kinetic methods are essential for the examination of elementary kinetic mechanisms of these motor proteins. Furthermore, rigorous kinetic analysis must also account for the thermodynamic properties of these complicated systems that reside in a dynamic equilibrium of oligomeric states, including the biologically active hexamer.
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Affiliation(s)
- Elizabeth C Duran
- Department of Chemistry, University of Alabama at BirminghamBirmingham, AL, United States
| | - Clarissa L Weaver
- Department of Chemistry, University of Alabama at BirminghamBirmingham, AL, United States
| | - Aaron L Lucius
- Department of Chemistry, University of Alabama at BirminghamBirmingham, AL, United States
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13
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Schwerter DP, Grimm I, Platta HW, Erdmann R. ATP-driven processes of peroxisomal matrix protein import. Biol Chem 2017; 398:607-624. [PMID: 27977397 DOI: 10.1515/hsz-2016-0293] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Accepted: 12/11/2016] [Indexed: 12/13/2022]
Abstract
In peroxisomal matrix protein import two processes directly depend on the binding and hydrolysis of ATP, both taking place at the late steps of the peroxisomal import cycle. First, ATP hydrolysis is required to initiate a ubiquitin-transfer cascade to modify the import (co-)receptors. These receptors display a dual localization in the cytosol and at the peroxisomal membrane, whereas only the membrane bound fraction receives the ubiquitin modification. The second ATP-dependent process of the import cycle is carried out by the two AAA+-proteins Pex1p and Pex6p. These ATPases form a heterohexameric complex, which is recruited to the peroxisomal import machinery by the membrane anchor protein Pex15p. The Pex1p/Pex6p complex recognizes the ubiquitinated import receptors, pulls them out of the membrane and releases them into the cytosol. There the deubiquitinated receptors are provided for further rounds of import. ATP binding and hydrolysis are required for Pex1p/Pex6p complex formation and receptor export. In this review, we summarize the current knowledge on the peroxisomal import cascade. In particular, we will focus on the ATP-dependent processes, which are so far best understood in the model organism Saccharomyces cerevisiae.
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Affiliation(s)
- Daniel P Schwerter
- Abteilung für Systembiochemie, Institut für Biochemie und Pathobiochemie, Medizinische Fakultät der Ruhr-Universität Bochum, Universitätsstr. 150, D-44780 Bochum
| | - Immanuel Grimm
- Abteilung für Systembiochemie, Institut für Biochemie und Pathobiochemie, Medizinische Fakultät der Ruhr-Universität Bochum, Universitätsstr. 150, D-44780 Bochum
| | - Harald W Platta
- Biochemie Intrazellulärer Transportprozesse, Medizinische Fakultät der Ruhr-Universität Bochum, D-44780 Bochum
| | - Ralf Erdmann
- Abteilung für Systembiochemie, Institut für Biochemie und Pathobiochemie, Medizinische Fakultät der Ruhr-Universität Bochum, Universitätsstr. 150, D-44780 Bochum
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14
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Abstract
Despite rapid advances in cardiovascular research and therapeutic strategies, ischemic heart disease (IHD) remains the leading cause of mortality worldwide. MicroRNAs (miRNAs) are small, noncoding RNAs which post transcriptionally regulate gene expression. In the past few years, miRNAs have emerged as key tools for the understanding of the pathophysiology of IHD, with potential uses as new biomarkers and therapeutic targets. Several studies report a regulatory role of miRNAs, with regard to fundamental components of IHD pathogenesis and progression, such as lipoprotein metabolism, atherogenesis, vascular calcification, platelet function, and angiogenesis. Due to their high stability in biofluids, circulating miRNAs have attracted attention as promising biomarkers of IHD, especially in cardiovascular risk prediction and the diagnosis of myocardial infarction. Furthermore, experimental studies have demonstrated the potential of miRNA-targeted therapy in improving hyperlipidemia, atherosclerosis, and angiogenesis. In this review, the current knowledge on the role of miRNAs in IHD and translational perspectives of their use is discussed.
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15
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Vilakazi CS, Dubery IA, Piater LA. Identification of lipopolysaccharide-interacting plasma membrane-type proteins in Arabidopsis thaliana. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2017; 111:155-165. [PMID: 27936405 DOI: 10.1016/j.plaphy.2016.11.025] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2016] [Accepted: 11/28/2016] [Indexed: 05/24/2023]
Abstract
Lipopolysaccharide (LPS) is an amphiphatic bacterial glycoconjugate found on the external membrane of Gram-negative bacteria. This endotoxin is considered as a microbe-associated molecular pattern (MAMP) molecule and has been shown to elicit defense responses in plants. Here, LPS-interacting proteins from Arabidopsis thaliana plasma membrane (PM)-type fractions were captured and identified in order to investigate those involved in LPS perception and linked to triggering of innate immune responses. A novel proteomics-based affinity-capture strategy coupled to liquid chromatography-tandem mass spectrometry (LC-MS/MS) was employed for the enrichment and identification of LPS-interacting proteins. As such, LPS isolated from Burkholderia cepacia (LPSB.cep.) was immobilized on three independent and distinct affinity-based matrices to serve as bait for interacting proteins from A. thaliana leaf and callus tissue. These were resolved by 1D electrophoresis and identified by mass spectrometry. Proteins specifically bound to LPSB.cep. have been implicated in membrane structure (e.g. COBRA-like and tubulin proteins), membrane trafficking and/or transport (e.g. soluble NSF attachment protein receptor (SNARE) proteins, patellin, aquaporin, PM instrinsic proteins (PIP) and H+-ATPase), signal transduction (receptor-like kinases and calcium-dependent protein kinases) as well as defense/stress responses (e.g. hypersensitive-induced response (HIR) proteins, jacalin-like lectin domain-containing protein and myrosinase-binding proteins). The novel affinity-capture strategy for the enrichment of LPS-interacting proteins proved to be effective, especially in the binding of proteins involved in plant defense responses, and can thus be used to elucidate LPS-mediated molecular recognition and disease mechanism(s).
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Affiliation(s)
- Cornelius S Vilakazi
- Department of Biochemistry, University of Johannesburg, Kingsway Campus, PO. Box 524, Auckland Park, 2006, South Africa
| | - Ian A Dubery
- Department of Biochemistry, University of Johannesburg, Kingsway Campus, PO. Box 524, Auckland Park, 2006, South Africa
| | - Lizelle A Piater
- Department of Biochemistry, University of Johannesburg, Kingsway Campus, PO. Box 524, Auckland Park, 2006, South Africa.
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16
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Cueto JA, Vanrell MC, Salassa BN, Nola S, Galli T, Colombo MI, Romano PS. Soluble N-ethylmaleimide-sensitive factor attachment protein receptors required during Trypanosoma cruzi parasitophorous vacuole development. Cell Microbiol 2017; 19. [PMID: 27992096 DOI: 10.1111/cmi.12713] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Revised: 12/02/2016] [Accepted: 12/15/2016] [Indexed: 01/19/2023]
Abstract
Trypanosoma cruzi, the etiologic agent of Chagas disease, is an obligate intracellular parasite that exploits different host vesicular pathways to invade the target cells. Vesicular and target soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) are key proteins of the intracellular membrane fusion machinery. During the early times of T. cruzi infection, several vesicles are attracted to the parasite contact sites in the plasma membrane. Fusion of these vesicles promotes the formation of the parasitic vacuole and parasite entry. In this work, we study the requirement and the nature of SNAREs involved in the fusion events that take place during T. cruzi infection. Our results show that inhibition of N-ethylmaleimide-sensitive factor protein, a protein required for SNARE complex disassembly, impairs T. cruzi infection. Both TI-VAMP/VAMP7 and cellubrevin/VAMP3, two v-SNAREs of the endocytic and exocytic pathways, are specifically recruited to the parasitophorous vacuole membrane in a synchronized manner but, although VAMP3 is acquired earlier than VAMP7, impairment of VAMP3 by tetanus neurotoxin fails to reduce T. cruzi infection. In contrast, reduction of VAMP7 activity by expression of VAMP7's longin domain, depletion by small interfering RNA or knockout, significantly decreases T. cruzi infection susceptibility as a result of a minor acquisition of lysosomal components to the parasitic vacuole. In addition, overexpression of the VAMP7 partner Vti1b increases the infection, whereas expression of a KIF5 kinesin mutant reduces VAMP7 recruitment to vacuole and, concomitantly, T. cruzi infection. Altogether, these data support a key role of TI-VAMP/VAMP7 in the fusion events that culminate in the T. cruzi parasitophorous vacuole development.
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Affiliation(s)
- Juan Agustín Cueto
- Laboratorio de Biología de Trypanosoma cruzi y la célula hospedadora - Instituto de Histología y Embriología (IHEM) "Dr. Mario H. Burgos" CCT CONICET Mendoza, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo-CONICET, Mendoza, Argentina.,Instituto de Fisiología, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - María Cristina Vanrell
- Laboratorio de Biología de Trypanosoma cruzi y la célula hospedadora - Instituto de Histología y Embriología (IHEM) "Dr. Mario H. Burgos" CCT CONICET Mendoza, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo-CONICET, Mendoza, Argentina
| | - Betiana Nebaí Salassa
- Laboratorio de Biología de Trypanosoma cruzi y la célula hospedadora - Instituto de Histología y Embriología (IHEM) "Dr. Mario H. Burgos" CCT CONICET Mendoza, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo-CONICET, Mendoza, Argentina
| | - Sébastien Nola
- Membrane Traffic in Health & Disease, INSERM ERL U950, Univ Paris Diderot, Sorbonne Paris Cité, Institut Jacques Monod, Paris, France
| | - Thierry Galli
- Membrane Traffic in Health & Disease, INSERM ERL U950, Univ Paris Diderot, Sorbonne Paris Cité, Institut Jacques Monod, Paris, France
| | - María Isabel Colombo
- Laboratorio de Biología de Trypanosoma cruzi y la célula hospedadora - Instituto de Histología y Embriología (IHEM) "Dr. Mario H. Burgos" CCT CONICET Mendoza, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo-CONICET, Mendoza, Argentina
| | - Patricia Silvia Romano
- Laboratorio de Biología de Trypanosoma cruzi y la célula hospedadora - Instituto de Histología y Embriología (IHEM) "Dr. Mario H. Burgos" CCT CONICET Mendoza, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo-CONICET, Mendoza, Argentina
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17
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Fan J, Zhou X, Wang Y, Kuang C, Sun Y, Liu X, Toomre D, Xu Y. Differential requirement forN-ethylmaleimide-sensitive factor in endosomal trafficking of transferrin receptor from anterograde trafficking of vesicular stomatitis virus glycoprotein G. FEBS Lett 2017; 591:273-281. [DOI: 10.1002/1873-3468.12532] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Accepted: 12/09/2016] [Indexed: 11/06/2022]
Affiliation(s)
- Jiannan Fan
- Department of Biomedical Engineering; Key Laboratory of Biomedical Engineering of Ministry of Education; Zhejiang University; Hangzhou China
- Zhejiang Provincial Key Laboratory of Cardio-Cerebral Vascular Detection Technology and Medicinal Effectiveness Appraisal; Zhejiang University; Hangzhou China
| | - Xiaoxu Zhou
- Department of Biomedical Engineering; Key Laboratory of Biomedical Engineering of Ministry of Education; Zhejiang University; Hangzhou China
- Zhejiang Provincial Key Laboratory of Cardio-Cerebral Vascular Detection Technology and Medicinal Effectiveness Appraisal; Zhejiang University; Hangzhou China
| | - Yanli Wang
- Department of Pathology; The First Affiliated Hospital; School of Medicine; Zhejiang University; Hangzhou China
| | - Cuifang Kuang
- Department of Optical Engineering; State Key Laboratory of Modern Optical Instrumentation; Zhejiang University; Hangzhou China
| | - Yonghong Sun
- Department of Biomedical Engineering; Key Laboratory of Biomedical Engineering of Ministry of Education; Zhejiang University; Hangzhou China
- Zhejiang Provincial Key Laboratory of Cardio-Cerebral Vascular Detection Technology and Medicinal Effectiveness Appraisal; Zhejiang University; Hangzhou China
| | - Xu Liu
- Department of Optical Engineering; State Key Laboratory of Modern Optical Instrumentation; Zhejiang University; Hangzhou China
| | - Derek Toomre
- Department of Cell Biology; Yale University School of Medicine; New Haven CT USA
| | - Yingke Xu
- Department of Biomedical Engineering; Key Laboratory of Biomedical Engineering of Ministry of Education; Zhejiang University; Hangzhou China
- Zhejiang Provincial Key Laboratory of Cardio-Cerebral Vascular Detection Technology and Medicinal Effectiveness Appraisal; Zhejiang University; Hangzhou China
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18
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Selvakumar D, Drescher MJ, Deckard NA, Ramakrishnan NA, Morley BJ, Drescher DG. Dopamine D1A directly interacts with otoferlin synaptic pathway proteins: Ca2+ and phosphorylation underlie an NSF-to-AP2mu1 molecular switch. Biochem J 2017; 474:79-104. [PMID: 27821621 PMCID: PMC6310132 DOI: 10.1042/bcj20160690] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Revised: 10/15/2016] [Accepted: 11/07/2016] [Indexed: 11/17/2022]
Abstract
Dopamine receptors regulate exocytosis via protein-protein interactions (PPIs) as well as via adenylyl cyclase transduction pathways. Evidence has been obtained for PPIs in inner ear hair cells coupling D1A to soluble N-ethylmaleimide-sensitive factor (NSF) attachment protein receptor (SNARE)-related proteins snapin, otoferlin, N-ethylmaleimide-sensitive factor (NSF), and adaptor-related protein complex 2, mu 1 (AP2mu1), dependent on [Ca2+] and phosphorylation. Specifically, the carboxy terminus of dopamine D1A was found to directly bind t-SNARE-associated protein snapin in teleost and mammalian hair cell models by yeast two-hybrid (Y2H) and pull-down assays, and snapin directly interacts with hair cell calcium-sensor otoferlin. Surface plasmon resonance (SPR) analysis, competitive pull-downs, and co-immunoprecipitation indicated that these interactions were promoted by Ca2+ and occur together. D1A was also found to separately interact with NSF, but with an inverse dependence on Ca2+ Evidence was obtained, for the first time, that otoferlin domains C2A, C2B, C2D, and C2F interact with NSF and AP2mu1, whereas C2C or C2E do not bind to either protein, representing binding characteristics consistent with respective inclusion or omission in individual C2 domains of the tyrosine motif YXXΦ. In competitive pull-down assays, as predicted by KD values from SPR (+Ca2+), C2F pulled down primarily NSF as opposed to AP2mu1. Phosphorylation of AP2mu1 gave rise to a reversal: an increase in binding by C2F to phosphorylated AP2mu1 was accompanied by a decrease in binding to NSF, consistent with a molecular switch for otoferlin from membrane fusion (NSF) to endocytosis (AP2mu1). An increase in phosphorylated AP2mu1 at the base of the cochlear inner hair cell was the observed response elicited by a dopamine D1A agonist, as predicted.
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Affiliation(s)
- Dakshnamurthy Selvakumar
- Laboratory of Bio-otology, Department of Otolaryngology, Wayne State University School of Medicine, Detroit, MI 48201, U.S.A
| | - Marian J Drescher
- Laboratory of Bio-otology, Department of Otolaryngology, Wayne State University School of Medicine, Detroit, MI 48201, U.S.A.
| | - Nathan A Deckard
- Laboratory of Bio-otology, Department of Otolaryngology, Wayne State University School of Medicine, Detroit, MI 48201, U.S.A
| | - Neeliyath A Ramakrishnan
- Laboratory of Bio-otology, Department of Otolaryngology, Wayne State University School of Medicine, Detroit, MI 48201, U.S.A
| | - Barbara J Morley
- Boys Town National Research Hospital, Omaha, Nebraska 68131, U.S.A
| | - Dennis G Drescher
- Laboratory of Bio-otology, Department of Otolaryngology, Wayne State University School of Medicine, Detroit, MI 48201, U.S.A
- Department of Biochemistry and Molecular Biology, Wayne State University School of Medicine, Detroit, MI 48201, U.S.A
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19
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Abstract
Secretion is essential to many of the roles that platelets play in the vasculature, e.g., thrombosis, angiogenesis, and inflammation, enabling platelets to modulate the microenvironment at sites of vascular lesions with a myriad of bioactive molecules stored in their granules. Past studies demonstrate that granule cargo release is mediated by Soluble NSF Attachment Protein Receptor (SNARE) proteins, which are required for granule-plasma membrane fusion. Several SNARE regulators, which control when, where, and how the SNAREs interact, have been identified in platelets. Additionally, platelet SNAREs are controlled by post-translational modifications, e.g., phosphorylation and acylation. Although there have been many recent insights into the mechanisms of platelet secretion, many questions remain: have we identified all the important regulators, does calcium directly control the process, and is platelet secretion polarized. In this review, we focus on the mechanics of platelet secretion and discuss how the secretory machinery functions in the pathway leading to membrane fusion and cargo release.
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Affiliation(s)
- Smita Joshi
- a Department of Molecular and Cellular Biochemistry , University of Kentucky , Lexington , KY , USA
| | - Sidney W Whiteheart
- a Department of Molecular and Cellular Biochemistry , University of Kentucky , Lexington , KY , USA
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20
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Kienle N, Kloepper TH, Fasshauer D. Shedding light on the expansion and diversification of the Cdc48 protein family during the rise of the eukaryotic cell. BMC Evol Biol 2016; 16:215. [PMID: 27756227 PMCID: PMC5070193 DOI: 10.1186/s12862-016-0790-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2016] [Accepted: 10/04/2016] [Indexed: 11/22/2022] Open
Abstract
Background A defining feature of eukaryotic cells is the presence of various distinct membrane-bound compartments with different metabolic roles. Material exchange between most compartments occurs via a sophisticated vesicle trafficking system. This intricate cellular architecture of eukaryotes appears to have emerged suddenly, about 2 billion years ago, from much less complex ancestors. How the eukaryotic cell acquired its internal complexity is poorly understood, partly because no prokaryotic precursors have been found for many key factors involved in compartmentalization. One exception is the Cdc48 protein family, which consists of several distinct classical ATPases associated with various cellular activities (AAA+) proteins with two consecutive AAA domains. Results Here, we have classified the Cdc48 family through iterative use of hidden Markov models and tree building. We found only one type, Cdc48, in prokaryotes, although a set of eight diverged members that function at distinct subcellular compartments were retrieved from eukaryotes and were probably present in the last eukaryotic common ancestor (LECA). Pronounced changes in sequence and domain structure during the radiation into the LECA set are delineated. Moreover, our analysis brings to light lineage-specific losses and duplications that often reflect important biological changes. Remarkably, we also found evidence for internal duplications within the LECA set that probably occurred during the rise of the eukaryotic cell. Conclusions Our analysis corroborates the idea that the diversification of the Cdc48 family is closely intertwined with the development of the compartments of the eukaryotic cell. Electronic supplementary material The online version of this article (doi:10.1186/s12862-016-0790-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Nickias Kienle
- Département des neurosciences fondamentales, Université de Lausanne, Rue du Bugnon 9, CH-1005, Lausanne, Switzerland
| | - Tobias H Kloepper
- Sir William Dunn School of Pathology, Research Group Cell Biology of Intercellular Signaling, University of Oxford, South Parks Road, Oxford, OX1 3RE, UK
| | - Dirk Fasshauer
- Département des neurosciences fondamentales, Université de Lausanne, Rue du Bugnon 9, CH-1005, Lausanne, Switzerland.
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21
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Wijeratne EMK, Gunaherath GMKB, Chapla VM, Tillotson J, de la Cruz F, Kang M, U'Ren JM, Araujo AR, Arnold AE, Chapman E, Gunatilaka AAL. Oxaspirol B with p97 Inhibitory Activity and Other Oxaspirols from Lecythophora sp. FL1375 and FL1031, Endolichenic Fungi Inhabiting Parmotrema tinctorum and Cladonia evansii. JOURNAL OF NATURAL PRODUCTS 2016; 79:340-52. [PMID: 26812276 PMCID: PMC4926610 DOI: 10.1021/acs.jnatprod.5b00986] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
A new metabolite, oxaspirol D (4), together with oxaspirols B (2) and C (3) were isolated from Lecythophora sp. FL1375, an endolichenic fungus isolated from Parmotrema tinctorum, whereas Lecythophora sp. FL1031 inhabiting the lichen Cladonia evansii afforded oxaspirols A (1), B (2), and C (3). Of these, oxaspirol B (2) showed moderate p97 ATPase inhibitory activity. A detailed characterization of all oxaspirols was undertaken because structures proposed for known oxaspirols have involved incomplete assignments of NMR spectroscopic data leading only to their planar structures. Thus, the naturally occurring isomeric mixture (2a and 2b) of oxaspirol B was separated as their diacetates (5a and 5b) and the structures and absolute configurations of 1, 2a, 2b, 3, and 4 were determined by the application of spectroscopic techniques including two-dimensional NMR and the modified Mosher's ester method. Oxaspirol B (2) and its diacetates 5a and 5b were evaluated for their ATPase inhibitory activities of p97, p97 mutants, and other ATP-utilizing enzymes, and only 2 was found to be active, indicating the requirement of some structural features in oxaspirols for their activity. Additional biochemical and cellular assays suggested that 2 was a reversible, non-ATP competitive, and specific inhibitor of p97.
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Affiliation(s)
- E. M. Kithsiri Wijeratne
- Natural Products Center, School of Natural Resources and the Environment, College of Agriculture and Life Sciences, University of Arizona, 250 East Valencia Road, Tucson, Arizona 85706, United States
| | - G. M. Kamal B. Gunaherath
- Natural Products Center, School of Natural Resources and the Environment, College of Agriculture and Life Sciences, University of Arizona, 250 East Valencia Road, Tucson, Arizona 85706, United States
- Department of Chemistry, Open University of Sri Lanka, Nugegoda 10250, Sri Lanka
| | - Vanessa M. Chapla
- Natural Products Center, School of Natural Resources and the Environment, College of Agriculture and Life Sciences, University of Arizona, 250 East Valencia Road, Tucson, Arizona 85706, United States
- Departamento de Química Orgânica, Instituto de Química, UNESP, Universidade Estadual Paulista, Araraquara, Sao Paulo 14800-900, Brazil
| | - Joseph Tillotson
- Department of Pharmacology and Toxicology, College of Pharmacy, University of Arizona, Tucson, Arizona 85721, United States
| | - Fabian de la Cruz
- Department of Pharmacology and Toxicology, College of Pharmacy, University of Arizona, Tucson, Arizona 85721, United States
| | - MinJing Kang
- Department of Pharmacology and Toxicology, College of Pharmacy, University of Arizona, Tucson, Arizona 85721, United States
| | - Jana M. U'Ren
- School of Plant Sciences, College of Agriculture and Life Sciences, University of Arizona, Tucson, Arizona 85721, United States
| | - Angela R. Araujo
- Departamento de Química Orgânica, Instituto de Química, UNESP, Universidade Estadual Paulista, Araraquara, Sao Paulo 14800-900, Brazil
| | - A. Elizabeth Arnold
- School of Plant Sciences, College of Agriculture and Life Sciences, University of Arizona, Tucson, Arizona 85721, United States
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, Arizona 85721, United States
| | - Eli Chapman
- Department of Pharmacology and Toxicology, College of Pharmacy, University of Arizona, Tucson, Arizona 85721, United States
| | - A. A. Leslie Gunatilaka
- Natural Products Center, School of Natural Resources and the Environment, College of Agriculture and Life Sciences, University of Arizona, 250 East Valencia Road, Tucson, Arizona 85706, United States
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22
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Nucleotide-dependent assembly of the peroxisomal receptor export complex. Sci Rep 2016; 6:19838. [PMID: 26842748 PMCID: PMC4740771 DOI: 10.1038/srep19838] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Accepted: 11/30/2015] [Indexed: 01/27/2023] Open
Abstract
Pex1p and Pex6p are two AAA-ATPases required for biogenesis of peroxisomes. Both proteins form a hetero-hexameric complex in an ATP-dependent manner, which has a dual localization in the cytosol and at the peroxisomal membrane. At the peroxisomal membrane, the complex is responsible for the release of the import receptor Pex5p at the end of the matrix protein import cycle. In this study, we analyzed the recruitment of the AAA-complex to its anchor protein Pex15p at the peroxisomal membrane. We show that the AAA-complex is properly assembled even under ADP-conditions and is able to bind efficiently to Pex15p in vivo. We reconstituted binding of the Pex1/6p-complex to Pex15p in vitro and show that Pex6p mediates binding to the cytosolic part of Pex15p via a direct interaction. Analysis of the isolated complex revealed a stoichiometry of Pex1p/Pex6p/Pex15p of 3:3:3, indicating that each Pex6p molecule of the AAA-complex binds Pex15p. Binding of the AAA-complex to Pex15p in particular and to the import machinery in general is stabilized when ATP is bound to the second AAA-domain of Pex6p and its hydrolysis is prevented. The data indicate that receptor release in peroxisomal protein import is associated with a nucleotide-depending Pex1/6p-cycle of Pex15p-binding and release.
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23
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Tan D, Blok NB, Rapoport TA, Walz T. Structures of the double-ring AAA ATPase Pex1-Pex6 involved in peroxisome biogenesis. FEBS J 2015; 283:986-92. [PMID: 26476099 DOI: 10.1111/febs.13569] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2015] [Revised: 10/12/2015] [Accepted: 10/15/2015] [Indexed: 11/27/2022]
Abstract
The Pex1 and Pex6 proteins are members of the AAA family of ATPases and are involved in peroxisome biogenesis. Recently, cryo-electron microscopy structures of the Pex1-Pex6 complex in different nucleotide states have been determined. This Structural Snapshot describes the structural features of the complex and their implications for its function, as well as questions that still await answers.
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Affiliation(s)
- Dongyan Tan
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA
| | - Neil B Blok
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA.,Department of Cell Biology, Howard Hughes Medical Institute, Harvard Medical School, Boston, MA, USA
| | - Tom A Rapoport
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA.,Department of Cell Biology, Howard Hughes Medical Institute, Harvard Medical School, Boston, MA, USA
| | - Thomas Walz
- The Rockefeller University, New York, NY, USA
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de Paola M, Bello OD, Michaut MA. Cortical Granule Exocytosis Is Mediated by Alpha-SNAP and N-Ethilmaleimide Sensitive Factor in Mouse Oocytes. PLoS One 2015; 10:e0135679. [PMID: 26267363 PMCID: PMC4534440 DOI: 10.1371/journal.pone.0135679] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Accepted: 07/25/2015] [Indexed: 11/18/2022] Open
Abstract
Cortical granule exocytosis (CGE), also known as cortical reaction, is a calcium- regulated secretion that represents a membrane fusion process during meiotic cell division of oocytes. The molecular mechanism of membrane fusion during CGE is still poorly understood and is thought to be mediated by the SNARE pathway; nevertheless, it is unkown if SNAP (acronym for soluble NSF attachment protein) and NSF (acronym for N-ethilmaleimide sensitive factor), two key proteins in the SNARE pathway, mediate CGE in any oocyte model. In this paper, we documented the gene expression of α-SNAP, γ-SNAP and NSF in mouse oocytes. Western blot analysis showed that the expression of these proteins maintains a similar level during oocyte maturation and early activation. Their localization was mainly observed at the cortical region of metaphase II oocytes, which is enriched in cortical granules. To evaluate the function of these proteins in CGE we set up a functional assay based on the quantification of cortical granules metaphase II oocytes activated parthenogenetically with strontium. Endogenous α-SNAP and NSF proteins were perturbed by microinjection of recombinant proteins or antibodies prior to CGE activation. The microinjection of wild type α-SNAP and the negative mutant of α-SNAP L294A in metaphase II oocytes inhibited CGE stimulated by strontium. NEM, an irreversibly inhibitor of NSF, and the microinjection of the negative mutant NSF D1EQ inhibited cortical reaction. The microinjection of anti-α-SNAP and anti-NSF antibodies was able to abolish CGE in activated metaphase II oocytes. The microinjection of anti-γ SNAP antibody had no effect on CGE. Our findings indicate, for the first time in any oocyte model, that α-SNAP, γ-SNAP, and NSF are expressed in mouse oocytes. We demonstrate that α-SNAP and NSF have an active role in CGE and propose a working model.
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Affiliation(s)
- Matilde de Paola
- Instituto de Histología y Embriología, Consejo Nacional de Investigaciones Científicas y Tecnológicas, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Oscar Daniel Bello
- Instituto de Histología y Embriología, Consejo Nacional de Investigaciones Científicas y Tecnológicas, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Marcela Alejandra Michaut
- Instituto de Histología y Embriología, Consejo Nacional de Investigaciones Científicas y Tecnológicas, Universidad Nacional de Cuyo, Mendoza, Argentina
- Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Cuyo, Mendoza, Argentina
- * E-mail:
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Unique double-ring structure of the peroxisomal Pex1/Pex6 ATPase complex revealed by cryo-electron microscopy. Proc Natl Acad Sci U S A 2015; 112:E4017-25. [PMID: 26170309 DOI: 10.1073/pnas.1500257112] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Members of the AAA family of ATPases assemble into hexameric double rings and perform vital functions, yet their molecular mechanisms remain poorly understood. Here, we report structures of the Pex1/Pex6 complex; mutations in these proteins frequently cause peroxisomal diseases. The structures were determined in the presence of different nucleotides by cryo-electron microscopy. Models were generated using a computational approach that combines Monte Carlo placement of structurally homologous domains into density maps with energy minimization and refinement protocols. Pex1 and Pex6 alternate in an unprecedented hexameric double ring. Each protein has two N-terminal domains, N1 and N2, structurally related to the single N domains in p97 and N-ethylmaleimide sensitive factor (NSF); N1 of Pex1 is mobile, but the others are packed against the double ring. The N-terminal ATPase domains are inactive, forming a symmetric D1 ring, whereas the C-terminal domains are active, likely in different nucleotide states, and form an asymmetric D2 ring. These results suggest how subunit activity is coordinated and indicate striking similarities between Pex1/Pex6 and p97, supporting the hypothesis that the Pex1/Pex6 complex has a role in peroxisomal protein import analogous to p97 in ER-associated protein degradation.
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Zhou Q, Huang X, Sun S, Li X, Wang HW, Sui SF. Cryo-EM structure of SNAP-SNARE assembly in 20S particle. Cell Res 2015; 25:551-60. [PMID: 25906996 DOI: 10.1038/cr.2015.47] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Revised: 02/25/2015] [Accepted: 03/17/2015] [Indexed: 12/12/2022] Open
Abstract
N-ethylmaleimide-sensitive factor (NSF) and α soluble NSF attachment proteins (α-SNAPs) work together within a 20S particle to disassemble and recycle the SNAP receptor (SNARE) complex after intracellular membrane fusion. To understand the disassembly mechanism of the SNARE complex by NSF and α-SNAP, we performed single-particle cryo-electron microscopy analysis of 20S particles and determined the structure of the α-SNAP-SNARE assembly portion at a resolution of 7.35 Å. The structure illustrates that four α-SNAPs wrap around the single left-handed SNARE helical bundle as a right-handed cylindrical assembly within a 20S particle. A conserved hydrophobic patch connecting helices 9 and 10 of each α-SNAP forms a chock protruding into the groove of the SNARE four-helix bundle. Biochemical studies proved that this structural element was critical for SNARE complex disassembly. Our study suggests how four α-SNAPs may coordinate with the NSF to tear the SNARE complex into individual proteins.
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Affiliation(s)
- Qiang Zhou
- State Key Laboratory of Biomembrane and Membrane Biotechnology, Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Xuan Huang
- State Key Laboratory of Biomembrane and Membrane Biotechnology, Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Shan Sun
- State Key Laboratory of Biomembrane and Membrane Biotechnology, Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Xueming Li
- Ministry of Education Key Laboratory of Protein Science, Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Hong-Wei Wang
- Ministry of Education Key Laboratory of Protein Science, Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Sen-Fang Sui
- State Key Laboratory of Biomembrane and Membrane Biotechnology, Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
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Murray RZ, Stow JL. Cytokine Secretion in Macrophages: SNAREs, Rabs, and Membrane Trafficking. Front Immunol 2014; 5:538. [PMID: 25386181 PMCID: PMC4209870 DOI: 10.3389/fimmu.2014.00538] [Citation(s) in RCA: 122] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Accepted: 10/10/2014] [Indexed: 12/21/2022] Open
Abstract
Macrophages have the capacity to rapidly secrete a wide range of inflammatory mediators that influence the development and extent of an inflammatory response. Newly synthesized and/or preformed stored cytokines and other inflammatory mediators are released upon stimulation, the timing, and volume of which is highly regulated. To finely tune this process, secretion is regulated at many levels; at the level of transcription and translation and post-translationally at the endoplasmic reticulum (ER), Golgi, and at or near the cell surface. Here, we discuss recent advances in deciphering these cytokine pathways in macrophages, focusing on recent discoveries regarding the cellular machinery and mechanisms implicated in the synthesis, trafficking, and secretion of cytokines. The specific roles of trafficking machinery including chaperones, GTPases, cytoskeletal proteins, and SNARE membrane fusion proteins will be discussed.
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Affiliation(s)
- Rachael Zoe Murray
- Institute of Health and Biomedical Innovation, Queensland University of Technology , Brisbane, QLD , Australia
| | - Jennifer Lea Stow
- Institute for Molecular Bioscience, The University of Queensland , Brisbane, QLD , Australia
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28
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Kang M, Wu T, Wijeratne EMK, Lau EC, Mason DJ, Mesa C, Tillotson J, Zhang DD, Gunatilaka AAL, La Clair JJ, Chapman E. Functional chromatography reveals three natural products that target the same protein with distinct mechanisms of action. Chembiochem 2014; 15:2125-31. [PMID: 25125376 PMCID: PMC4187115 DOI: 10.1002/cbic.201402258] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2014] [Indexed: 01/12/2023]
Abstract
Access to lead compounds with defined molecular targets continues to be a barrier to the translation of natural product resources. As a solution, we developed a system that uses discrete, recombinant proteins as the vehicles for natural product isolation. Here, we describe the use of this functional chromatographic method to identify natural products that bind to the AAA+ chaperone, p97, a promising cancer target. Application of this method to a panel of fungal and plant extracts identified rheoemodin, 1-hydroxydehydroherbarin, and phomapyrrolidone A as distinct p97 modulators. Excitingly, each of these molecules displayed a unique mechanism of p97 modulation. This discovery provides strong support for the application of functional chromatography to the discovery of protein modulators that would likely escape traditional high-throughput or phenotypic screening platforms.
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Affiliation(s)
- MinJin Kang
- College of Pharmacy, Department of Pharmacology and Toxicology, University of Arizona, Tucson, AZ 85721-0207, United States
| | - Tongde Wu
- College of Pharmacy, Department of Pharmacology and Toxicology, University of Arizona, Tucson, AZ 85721-0207, United States
| | - E. M. Kithsiri Wijeratne
- Southwest Center for Natural Products Research and Commercialization, School of Natural Resources and the Environment, College of Agriculture and Life Sciences, University of Arizona, Tucson, AZ 85706-6800, United States
| | - Eric C. Lau
- College of Pharmacy, Department of Pharmacology and Toxicology, University of Arizona, Tucson, AZ 85721-0207, United States
| | - Damian J. Mason
- College of Pharmacy, Department of Pharmacology and Toxicology, University of Arizona, Tucson, AZ 85721-0207, United States
| | - Celestina Mesa
- College of Pharmacy, Department of Pharmacology and Toxicology, University of Arizona, Tucson, AZ 85721-0207, United States
| | - Joseph Tillotson
- College of Pharmacy, Department of Pharmacology and Toxicology, University of Arizona, Tucson, AZ 85721-0207, United States
| | - Donna D. Zhang
- College of Pharmacy, Department of Pharmacology and Toxicology, University of Arizona, Tucson, AZ 85721-0207, United States
| | - A. A. Leslie Gunatilaka
- Southwest Center for Natural Products Research and Commercialization, School of Natural Resources and the Environment, College of Agriculture and Life Sciences, University of Arizona, Tucson, AZ 85706-6800, United States
| | - James J. La Clair
- Xenobe Research Institute, P. O. Box 3052, San Diego, CA 92163-1052, United States
| | - Eli Chapman
- College of Pharmacy, Department of Pharmacology and Toxicology, University of Arizona, Tucson, AZ 85721-0207, United States
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29
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Olivares AO, Nager AR, Iosefson O, Sauer RT, Baker TA. Mechanochemical basis of protein degradation by a double-ring AAA+ machine. Nat Struct Mol Biol 2014; 21:871-5. [PMID: 25195048 PMCID: PMC4190165 DOI: 10.1038/nsmb.2885] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Accepted: 08/06/2014] [Indexed: 02/08/2023]
Abstract
Molecular machines containing double or single AAA+ rings power energy-dependent protein degradation and other critical cellular processes, including disaggregation and remodeling of macromolecular complexes. How the mechanical activities of double-ring and single-ring AAA+ enzymes differ is unknown. Using single-molecule optical trapping, we determine how the double-ring ClpA enzyme from Escherichia coli mechanically degrades proteins in complex with the ClpP peptidase. We demonstrate that ClpA unfolds some protein substrates substantially faster than the single-ring ClpX enzyme, which also degrades substrates in collaboration with ClpP. We find that ClpA is a slower polypeptide translocase and moves in physical steps that are smaller and more regular than steps taken by ClpX. These direct measurements of protein unfolding and translocation define the core mechanochemical behavior of a double-ring AAA+ machine and provide insight into the degradation of proteins that unfold via metastable intermediates.
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Affiliation(s)
- Adrian O Olivares
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Andrew R Nager
- 1] Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA. [2]
| | - Ohad Iosefson
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Robert T Sauer
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Tania A Baker
- 1] Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA. [2] Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
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30
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Iwata K, Matsuzaki H, Tachibana T, Ohno K, Yoshimura S, Takamura H, Yamada K, Matsuzaki S, Nakamura K, Tsuchiya KJ, Matsumoto K, Tsujii M, Sugiyama T, Katayama T, Mori N. N-ethylmaleimide-sensitive factor interacts with the serotonin transporter and modulates its trafficking: implications for pathophysiology in autism. Mol Autism 2014; 5:33. [PMID: 24834316 PMCID: PMC4022412 DOI: 10.1186/2040-2392-5-33] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2014] [Accepted: 04/24/2014] [Indexed: 01/23/2023] Open
Abstract
Background Changes in serotonin transporter (SERT) function have been implicated in autism. SERT function is influenced by the number of transporter molecules present at the cell surface, which is regulated by various cellular mechanisms including interactions with other proteins. Thus, we searched for novel SERT-binding proteins and investigated whether the expression of one such protein was affected in subjects with autism. Methods Novel SERT-binding proteins were examined by a pull-down system. Alterations of SERT function and membrane expression upon knockdown of the novel SERT-binding protein were studied in HEK293-hSERT cells. Endogenous interaction of SERT with the protein was evaluated in mouse brains. Alterations in the mRNA expression of SERT (SLC6A4) and the SERT-binding protein in the post-mortem brains and the lymphocytes of autism patients were compared to nonclinical controls. Results N-ethylmaleimide-sensitive factor (NSF) was identified as a novel SERT-binding protein. NSF was co-localized with SERT at the plasma membrane, and NSF knockdown resulted in decreased SERT expression at the cell membranes and decreased SERT uptake function. NSF was endogenously co-localized with SERT and interacted with SERT. While SLC6A4 expression was not significantly changed, NSF expression tended to be reduced in post-mortem brains, and was significantly reduced in lymphocytes of autistic subjects, which correlated with the severity of the clinical symptoms. Conclusions These data clearly show that NSF interacts with SERT under physiological conditions and is required for SERT membrane trafficking and uptake function. A possible role for NSF in the pathophysiology of autism through modulation of SERT trafficking, is suggested.
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Affiliation(s)
- Keiko Iwata
- Research Center for Child Mental Development, University of Fukui, Fukui, Japan ; Department of Development of Functional Brain Activities, United Graduate School of Child Development, Osaka University, Kanazawa University, Hamamatsu University School of Medicine, Chiba University and University of Fukui, Fukui, Japan
| | - Hideo Matsuzaki
- Research Center for Child Mental Development, University of Fukui, Fukui, Japan ; Department of Development of Functional Brain Activities, United Graduate School of Child Development, Osaka University, Kanazawa University, Hamamatsu University School of Medicine, Chiba University and University of Fukui, Fukui, Japan ; Research Center for Child Mental Development, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Taro Tachibana
- Department of Bioengineering, Graduate School of Engineering, Osaka City University, Osaka, Japan
| | - Koji Ohno
- Department of Anatomy, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Saori Yoshimura
- Department of Bioengineering, Graduate School of Engineering, Osaka City University, Osaka, Japan
| | - Hironori Takamura
- Department of Molecular Brain Science, United Graduate School of Child Development, Osaka University, Kanazawa University, Hamamatsu University School of Medicine, Chiba University and University of Fukui, Suita, Osaka, Japan ; Molecular Research Center for Children's Mental Development, United Graduate School of Child Development, Osaka University, Suita, Osaka, Japan
| | - Kohei Yamada
- Department of Molecular Brain Science, United Graduate School of Child Development, Osaka University, Kanazawa University, Hamamatsu University School of Medicine, Chiba University and University of Fukui, Suita, Osaka, Japan ; Molecular Research Center for Children's Mental Development, United Graduate School of Child Development, Osaka University, Suita, Osaka, Japan
| | - Shinsuke Matsuzaki
- Department of Molecular Brain Science, United Graduate School of Child Development, Osaka University, Kanazawa University, Hamamatsu University School of Medicine, Chiba University and University of Fukui, Suita, Osaka, Japan
| | - Kazuhiko Nakamura
- Department of Psychiatry, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Kenji J Tsuchiya
- Research Center for Child Mental Development, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Kaori Matsumoto
- Research Center for Child Mental Development, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Masatsugu Tsujii
- Research Center for Child Mental Development, Hamamatsu University School of Medicine, Hamamatsu, Japan ; Faculty of Contemporary Sociology, Chukyo University, Toyota, Japan
| | - Toshirou Sugiyama
- Department of Child and Adolescent Psychiatry, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Taiichi Katayama
- Department of Molecular Brain Science, United Graduate School of Child Development, Osaka University, Kanazawa University, Hamamatsu University School of Medicine, Chiba University and University of Fukui, Suita, Osaka, Japan
| | - Norio Mori
- Research Center for Child Mental Development, Hamamatsu University School of Medicine, Hamamatsu, Japan ; Department of Psychiatry, Hamamatsu University School of Medicine, Hamamatsu, Japan
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31
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Allen RM, Marquart TJ, Jesse JJ, Baldán A. Control of very low-density lipoprotein secretion by N-ethylmaleimide-sensitive factor and miR-33. Circ Res 2014; 115:10-22. [PMID: 24753547 DOI: 10.1161/circresaha.115.303100] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
RATIONALE Several reports suggest that antisense oligonucleotides against miR-33 might reduce cardiovascular risk in patients by accelerating the reverse cholesterol transport pathway. However, conflicting reports exist about the impact of anti-miR-33 therapy on the levels of very low-density lipoprotein-triglycerides (VLDL-TAG). OBJECTIVE We test the hypothesis that miR-33 controls hepatic VLDL-TAG secretion. METHODS AND RESULTS Using therapeutic silencing of miR-33 and adenoviral overexpression of miR-33, we show that miR-33 limits hepatic secretion of VLDL-TAG by targeting N-ethylmaleimide-sensitive factor (NSF), both in vivo and in primary hepatocytes. We identify conserved sequences in the 3'UTR of NSF as miR-33 responsive elements and show that Nsf is specifically recruited to the RNA-induced silencing complex following induction of miR-33. In pulse-chase experiments, either miR-33 overexpression or knock-down of Nsf lead to decreased secretion of apolipoproteins and TAG in primary hepatocytes, compared with control cells. Importantly, Nsf rescues miR-33-dependent reduced secretion. Finally, we show that overexpression of Nsf in vivo increases global hepatic secretion and raises plasma VLDL-TAG. CONCLUSIONS Together, our data reveal key roles for the miR-33-NSF axis during hepatic secretion and suggest that caution should be taken with anti-miR-33-based therapies because they might raise proatherogenic VLDL-TAG levels.
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Affiliation(s)
- Ryan M Allen
- From the Edward A. Doisy Department of Biochemistry and Molecular Biology (R.M.A., T.J.M., J.J.J, A.B.) and Center for Cardiovascular Research (R.M.A., T.J.M., A.B.), St. Louis University, St. Louis, MO
| | - Tyler J Marquart
- From the Edward A. Doisy Department of Biochemistry and Molecular Biology (R.M.A., T.J.M., J.J.J, A.B.) and Center for Cardiovascular Research (R.M.A., T.J.M., A.B.), St. Louis University, St. Louis, MO
| | - Jordan J Jesse
- From the Edward A. Doisy Department of Biochemistry and Molecular Biology (R.M.A., T.J.M., J.J.J, A.B.) and Center for Cardiovascular Research (R.M.A., T.J.M., A.B.), St. Louis University, St. Louis, MO
| | - Angel Baldán
- From the Edward A. Doisy Department of Biochemistry and Molecular Biology (R.M.A., T.J.M., J.J.J, A.B.) and Center for Cardiovascular Research (R.M.A., T.J.M., A.B.), St. Louis University, St. Louis, MO.
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32
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Billaud M, Lohman AW, Johnstone SR, Biwer LA, Mutchler S, Isakson BE. Regulation of cellular communication by signaling microdomains in the blood vessel wall. Pharmacol Rev 2014; 66:513-69. [PMID: 24671377 DOI: 10.1124/pr.112.007351] [Citation(s) in RCA: 82] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
It has become increasingly clear that the accumulation of proteins in specific regions of the plasma membrane can facilitate cellular communication. These regions, termed signaling microdomains, are found throughout the blood vessel wall where cellular communication, both within and between cell types, must be tightly regulated to maintain proper vascular function. We will define a cellular signaling microdomain and apply this definition to the plethora of means by which cellular communication has been hypothesized to occur in the blood vessel wall. To that end, we make a case for three broad areas of cellular communication where signaling microdomains could play an important role: 1) paracrine release of free radicals and gaseous molecules such as nitric oxide and reactive oxygen species; 2) role of ion channels including gap junctions and potassium channels, especially those associated with the endothelium-derived hyperpolarization mediated signaling, and lastly, 3) mechanism of exocytosis that has considerable oversight by signaling microdomains, especially those associated with the release of von Willebrand factor. When summed, we believe that it is clear that the organization and regulation of signaling microdomains is an essential component to vessel wall function.
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Affiliation(s)
- Marie Billaud
- Dept. of Molecular Physiology and Biophysics, University of Virginia School of Medicine, PO Box 801394, Charlottesville, VA 22902.
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Schulze U, Vollenbröker B, Braun DA, Van Le T, Granado D, Kremerskothen J, Fränzel B, Klosowski R, Barth J, Fufezan C, Wolters DA, Pavenstädt H, Weide T. The Vac14-interaction network is linked to regulators of the endolysosomal and autophagic pathway. Mol Cell Proteomics 2014; 13:1397-411. [PMID: 24578385 DOI: 10.1074/mcp.m113.034108] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The scaffold protein Vac14 acts in a complex with the lipid kinase PIKfyve and its counteracting phosphatase FIG4, regulating the interconversion of phosphatidylinositol-3-phosphate to phosphatidylinositol-3,5-bisphosphate. Dysfunctional Vac14 mutants, a deficiency of one of the Vac14 complex components, or inhibition of PIKfyve enzymatic activity results in the formation of large vacuoles in cells. How these vacuoles are generated and which processes are involved are only poorly understood. Here we show that ectopic overexpression of wild-type Vac14 as well as of the PIKfyve-binding deficient Vac14 L156R mutant causes vacuoles. Vac14-dependent vacuoles and PIKfyve inhibitor-dependent vacuoles resulted in elevated levels of late endosomal, lysosomal, and autophagy-associated proteins. However, only late endosomal marker proteins were bound to the membranes of these enlarged vacuoles. In order to decipher the linkage between the Vac14 complex and regulators of the endolysosomal pathway, a protein affinity approach combined with multidimensional protein identification technology was conducted, and novel molecular links were unraveled. We found and verified the interaction of Rab9 and the Rab7 GAP TBC1D15 with Vac14. The identified Rab-related interaction partners support the theory that the regulation of vesicular transport processes and phosphatidylinositol-modifying enzymes are tightly interconnected.
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Affiliation(s)
- Ulf Schulze
- From the ‡Department of Internal Medicine D, Molecular Nephrology, University Hospital of Muenster, Albert-Schweitzer Campus 1, A14, D-48149 Muenster, Germany
| | - Beate Vollenbröker
- From the ‡Department of Internal Medicine D, Molecular Nephrology, University Hospital of Muenster, Albert-Schweitzer Campus 1, A14, D-48149 Muenster, Germany
| | - Daniela A Braun
- From the ‡Department of Internal Medicine D, Molecular Nephrology, University Hospital of Muenster, Albert-Schweitzer Campus 1, A14, D-48149 Muenster, Germany
| | - Truc Van Le
- From the ‡Department of Internal Medicine D, Molecular Nephrology, University Hospital of Muenster, Albert-Schweitzer Campus 1, A14, D-48149 Muenster, Germany
| | - Daniel Granado
- From the ‡Department of Internal Medicine D, Molecular Nephrology, University Hospital of Muenster, Albert-Schweitzer Campus 1, A14, D-48149 Muenster, Germany
| | - Joachim Kremerskothen
- From the ‡Department of Internal Medicine D, Molecular Nephrology, University Hospital of Muenster, Albert-Schweitzer Campus 1, A14, D-48149 Muenster, Germany
| | - Benjamin Fränzel
- ‖Analytical Chemistry NC4/72, Biomolecular Mass Spectrometry/Proteincenter, Ruhr-University Bochum, Universitätsstr. 150, D-44801 Bochum, Germany
| | - Rafael Klosowski
- ‖Analytical Chemistry NC4/72, Biomolecular Mass Spectrometry/Proteincenter, Ruhr-University Bochum, Universitätsstr. 150, D-44801 Bochum, Germany
| | - Johannes Barth
- ‡‡Institute of Plant Biology and Biotechnology, University of Muenster, Schlossplatz 8, D-48143 Muenster, Germany
| | - Christian Fufezan
- ‡‡Institute of Plant Biology and Biotechnology, University of Muenster, Schlossplatz 8, D-48143 Muenster, Germany
| | - Dirk A Wolters
- ‖Analytical Chemistry NC4/72, Biomolecular Mass Spectrometry/Proteincenter, Ruhr-University Bochum, Universitätsstr. 150, D-44801 Bochum, Germany
| | - Hermann Pavenstädt
- From the ‡Department of Internal Medicine D, Molecular Nephrology, University Hospital of Muenster, Albert-Schweitzer Campus 1, A14, D-48149 Muenster, Germany;
| | - Thomas Weide
- From the ‡Department of Internal Medicine D, Molecular Nephrology, University Hospital of Muenster, Albert-Schweitzer Campus 1, A14, D-48149 Muenster, Germany;
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Zhang Y, Tang W, Zhang H, Niu X, Xu Y, Zhang J, Gao K, Pan W, Boggon TJ, Toomre D, Min W, Wu D. A network of interactions enables CCM3 and STK24 to coordinate UNC13D-driven vesicle exocytosis in neutrophils. Dev Cell 2014; 27:215-226. [PMID: 24176643 DOI: 10.1016/j.devcel.2013.09.021] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2013] [Revised: 09/14/2013] [Accepted: 09/22/2013] [Indexed: 12/15/2022]
Abstract
Neutrophil degranulation plays an important role in acute innate immune responses and is tightly regulated because the granule contents can cause tissue damage. However, this regulation remains poorly understood. Here, we identify the complex of STK24 and CCM3 as being an important regulator of neutrophil degranulation. Lack of either STK24 or CCM3 increases the release of a specific granule pool without affecting other neutrophil functions. STK24 appears to suppress exocytosis by interacting and competing with UNC13D C2B domain for lipid binding, whereas CCM3 has dual roles in exocytosis regulation. Although CCM3 stabilizes STK24, it counteracts STK24-mediated inhibition of exocytosis by recruiting STK24 away from the C2B domain through its Ca(2+)-sensitive interaction with UNC13D C2A domain. This STK24/CCM3-regulated exocytosis plays an important role in the protection of kidneys from ischemia-reperfusion injury. Together, these findings reveal a function of the STK24 and CCM3 complex in the regulation of ligand-stimulated exocytosis.
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Affiliation(s)
- Yong Zhang
- Department of Pharmacology, Yale School of Medicine, New Haven, CT 06520, USA; Department of Vascular Biology and Therapeutic Program, Yale School of Medicine, New Haven, CT 06520, USA
| | - Wenwen Tang
- Department of Pharmacology, Yale School of Medicine, New Haven, CT 06520, USA; Department of Vascular Biology and Therapeutic Program, Yale School of Medicine, New Haven, CT 06520, USA
| | - Haifeng Zhang
- Department of Vascular Biology and Therapeutic Program, Yale School of Medicine, New Haven, CT 06520, USA; Department of Pathology, Yale School of Medicine, New Haven, CT 06520, USA
| | - Xiaofeng Niu
- Department of Pharmacology, Yale School of Medicine, New Haven, CT 06520, USA; Department of Vascular Biology and Therapeutic Program, Yale School of Medicine, New Haven, CT 06520, USA
| | - Yingke Xu
- Department of Cell Biology, Yale School of Medicine, New Haven, CT 06520, USA
| | - Jiasheng Zhang
- Department of Internal Medicine, Yale School of Medicine, New Haven, CT 06520, USA
| | - Kun Gao
- Department of Pharmacology, Yale School of Medicine, New Haven, CT 06520, USA; Department of Vascular Biology and Therapeutic Program, Yale School of Medicine, New Haven, CT 06520, USA
| | - Weijun Pan
- Key Laboratory of Stem Cell Biology, Institute of Health Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences and Shanghai Jiao Tong University School of Medicine, 200025 Shanghai, China
| | - Titus J Boggon
- Department of Pharmacology, Yale School of Medicine, New Haven, CT 06520, USA
| | - Derek Toomre
- Department of Cell Biology, Yale School of Medicine, New Haven, CT 06520, USA
| | - Wang Min
- Department of Vascular Biology and Therapeutic Program, Yale School of Medicine, New Haven, CT 06520, USA; Department of Pathology, Yale School of Medicine, New Haven, CT 06520, USA.
| | - Dianqing Wu
- Department of Pharmacology, Yale School of Medicine, New Haven, CT 06520, USA; Department of Vascular Biology and Therapeutic Program, Yale School of Medicine, New Haven, CT 06520, USA.
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Platta HW, Hagen S, Reidick C, Erdmann R. The peroxisomal receptor dislocation pathway: to the exportomer and beyond. Biochimie 2013; 98:16-28. [PMID: 24345375 DOI: 10.1016/j.biochi.2013.12.009] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Accepted: 12/05/2013] [Indexed: 12/29/2022]
Abstract
The biogenesis of peroxisomes is an ubiquitin-dependent process. In particular, the import of matrix proteins into the peroxisomal lumen requires the modification of import receptors with ubiquitin. The matrix proteins are synthesized on free polyribosomes in the cytosol and are recognized by import receptors via a peroxisomal targeting sequence (PTS). Subsequent to the transport of the receptor/cargo-complex to the peroxisomal membrane and the release of the cargo into the peroxisomal lumen, the PTS-receptors are exported back to the cytosol for further rounds of matrix protein import. The exportomer represents the molecular machinery required for the retrotranslocation of the PTS-receptors. It comprises enzymes for the ubiquitination as well as for the ATP-dependent extraction of the PTS-receptors from the peroxisomal membrane. Furthermore, recent evidence indicates a mechanistic interconnection of the ATP-dependent removal of the PTS-receptors with the translocation of the matrix protein into the organellar lumen. Interestingly, the components of the peroxisomal exportomer seem also to be involved in cellular tasks that are distinct from the ubiquitination and dislocation of the peroxisomal PTS-receptors. This includes work that indicates a central function of this machinery in the export of peroxisomal matrix proteins in plants, while a subset of exportomer components is involved in the meiocyte formation in some fungi, the peroxisome-chloroplast contact during photorespiration in plants and possibly even the selective degradation of peroxisomes via pexophagy. In this review, we want to discuss the central role of the exportomer during matrix protein import, but also highlight distinct roles of exportomer constituents in additional cellular processes. This article is part of a Special Issue entitled: Peroxisomes: biogenesis, functions and diseases.
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Affiliation(s)
- Harald W Platta
- Biochemie Intrazellulärer Transportprozesse, Ruhr-Universität Bochum, Universitätsstr. 150, D-44780 Bochum, Germany.
| | - Stefanie Hagen
- Systembiochemie, Ruhr-Universität Bochum, Universitätsstr. 150, D-44780 Bochum, Germany
| | - Christina Reidick
- Biochemie Intrazellulärer Transportprozesse, Ruhr-Universität Bochum, Universitätsstr. 150, D-44780 Bochum, Germany
| | - Ralf Erdmann
- Systembiochemie, Ruhr-Universität Bochum, Universitätsstr. 150, D-44780 Bochum, Germany.
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Naydenov NG, Feygin A, Wang L, Ivanov AI. N-ethylmaleimide-sensitive factor attachment protein α (αSNAP) regulates matrix adhesion and integrin processing in human epithelial cells. J Biol Chem 2013; 289:2424-39. [PMID: 24311785 DOI: 10.1074/jbc.m113.498691] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Integrin-based adhesion to the extracellular matrix (ECM) plays critical roles in controlling differentiation, survival, and motility of epithelial cells. Cells attach to the ECM via dynamic structures called focal adhesions (FA). FA undergo constant remodeling mediated by vesicle trafficking and fusion. A soluble N-ethylmaleimide-sensitive factor (NSF) attachment protein α (αSNAP) is an essential mediator of membrane fusion; however, its roles in regulating ECM adhesion and cell motility remain unexplored. In this study, we found that siRNA-mediated knockdown of αSNAP induced detachment of intestinal epithelial cells, whereas overexpression of αSNAP increased ECM adhesion and inhibited cell invasion. Loss of αSNAP impaired Golgi-dependent glycosylation and trafficking of β1 integrin and decreased phosphorylation of focal adhesion kinase (FAK) and paxillin resulting in FA disassembly. These effects of αSNAP depletion on ECM adhesion were independent of apoptosis and NSF. In agreement with our previous reports that Golgi fragmentation mediates cellular effects of αSNAP knockdown, we found that either pharmacologic or genetic disruption of the Golgi recapitulated all the effects of αSNAP depletion on ECM adhesion. Furthermore, our data implicates β1 integrin, FAK, and paxillin in mediating the observed pro-adhesive effects of αSNAP. These results reveal novel roles for αSNAP in regulating ECM adhesion and motility of epithelial cells.
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Song Y, Eng M, Ghabrial AS. Focal defects in single-celled tubes mutant for Cerebral cavernous malformation 3, GCKIII, or NSF2. Dev Cell 2013; 25:507-19. [PMID: 23763949 DOI: 10.1016/j.devcel.2013.05.002] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2012] [Revised: 04/09/2013] [Accepted: 05/02/2013] [Indexed: 10/26/2022]
Abstract
Tubes of differing cellular architecture connect into networks. In the Drosophila tracheal system, two tube types connect within single cells (terminal cells); however, the genes that mediate this interconnection are unknown. Here we characterize two genes that are essential for this process: lotus, required for maintaining a connection between the tubes, and wheezy, required to prevent local tube dilation. We find that lotus encodes N-ethylmaleimide sensitive factor 2 (NSF2), whereas wheezy encodes Germinal center kinase III (GCKIII). GCKIIIs are effectors of Cerebral cavernous malformation 3 (CCM3), a protein mutated in vascular disease. Depletion of Ccm3 by RNA interference phenocopies wheezy; thus, CCM3 and GCKIII, which prevent capillary dilation in humans, prevent tube dilation in Drosophila trachea. Ectopic junctional and apical proteins are present in wheezy terminal cells, and we show that tube dilation is suppressed by reduction of NSF2, of the apical determinant Crumbs, or of septate junction protein Varicose.
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Affiliation(s)
- Yanjun Song
- Department of Cell and Developmental Biology, Perelman School of Medicine, BRBII/III Room 1214, 421 Curie Boulevard, University of Pennsylvania, Philadelphia, PA 19104, USA
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38
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Hutt DM, Balch WE. Expanding proteostasis by membrane trafficking networks. Cold Spring Harb Perspect Biol 2013; 5:cshperspect.a013383. [PMID: 23426524 DOI: 10.1101/cshperspect.a013383] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The folding biology common to all three kingdoms of life (Archaea, Bacteria, and Eukarya) is proteostasis. The proteostasis network (PN) functions as a "cloud" to generate, protect, and degrade the proteome. Whereas microbes (Bacteria, Archaea) have a single compartment, Eukarya have numerous subcellular compartments. We examine evidence that Eukarya compartments use coat, tether, and fusion (CTF) membrane trafficking components to form an evolutionarily advanced arm of the PN that we refer to as the "trafficking PN" (TPN). We suggest that the TPN builds compartments by generating a mosaic of integrated cargo-specific trafficking signatures (TRaCKS). TRaCKS control the temporal and spatial features of protein-folding biology based on the Anfinsen principle that the local environment plays a critical role in managing protein structure. TPN-generated endomembrane compartments apply a "quinary" level of structural control to modify the secondary, tertiary, and quaternary structures defined by the primary polypeptide-chain sequence. The development of Anfinsen compartments provides a unifying foundation for understanding the purpose of endomembrane biology and its capacity to drive extant Eukarya function and diversity.
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Affiliation(s)
- Darren M Hutt
- Department of Cell Biology and Department of Chemical Physiology, The Skaggs Institute for Chemical Biology and the Dorris Institute for Neurological Diseases, The Scripps Research Institute, La Jolla, California 92037, USA
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Cipriano DJ, Jung J, Vivona S, Fenn TD, Brunger AT, Bryant Z. Processive ATP-driven substrate disassembly by the N-ethylmaleimide-sensitive factor (NSF) molecular machine. J Biol Chem 2013; 288:23436-45. [PMID: 23775070 PMCID: PMC4520572 DOI: 10.1074/jbc.m113.476705] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
SNARE proteins promote membrane fusion by forming a four-stranded parallel helical bundle that brings the membranes into close proximity. Post-fusion, the complex is disassembled by an AAA+ ATPase called N-ethylmaleimide-sensitive factor (NSF). We present evidence that NSF uses a processive unwinding mechanism to disassemble SNARE proteins. Using a real-time disassembly assay based on fluorescence dequenching, we correlate NSF-driven disassembly rates with the SNARE-activated ATPase activity of NSF. Neuronal SNAREs activate the ATPase rate of NSF by ∼26-fold. One SNARE complex takes an average of ∼5 s to disassemble in a process that consumes ∼50 ATP. Investigations of substrate requirements show that NSF is capable of disassembling a truncated SNARE substrate consisting of only the core SNARE domain, but not an unrelated four-stranded coiled-coil. NSF can also disassemble an engineered double-length SNARE complex, suggesting a processive unwinding mechanism. We further investigated processivity using single-turnover experiments, which show that SNAREs can be unwound in a single encounter with NSF. We propose a processive helicase-like mechanism for NSF in which ∼1 residue is unwound for every hydrolyzed ATP molecule.
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Affiliation(s)
- Daniel J Cipriano
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, California 94305, USA
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40
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Liu CC, Sun S, Sui SF. The role of the N-D1 linker of the N-ethylmaleimide-sensitive factor in the SNARE disassembly. PLoS One 2013; 8:e64346. [PMID: 23667709 PMCID: PMC3646813 DOI: 10.1371/journal.pone.0064346] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2013] [Accepted: 04/10/2013] [Indexed: 12/04/2022] Open
Abstract
N-ethylmaleimide-sensitive factor (NSF) is a member of the type II AAA+ (ATPase associated with various cellular activities) family. It plays a critical role in intracellular membrane trafficking by disassembling soluble NSF attachment protein receptor (SNARE) complexes. Each NSF protomer consists of an N-terminal domain (N domain) followed by two AAA ATPase domains (D1 and D2) in tandem. The N domain is required for SNARE/α-SNAP binding and the D1 domain accounts for the majority of ATP hydrolysis. Little is known about the role of the N-D1 linker in the NSF function. This study presents detailed mutagenesis analyses of NSF N-D1 linker, dissecting its role in the SNARE disassembly, the SNARE/α-SNAP complex binding, the basal ATPase activity and the SNARE/α-SNAP stimulated ATPase activity. Our results show that the N-terminal region of the N-D1 linker associated mutants cause severe defect in SNARE complex disassembly, but little effects on the SNARE/α-SNAP complex binding, the basal and the SNARE/α-SNAP stimulated ATPase activity, suggesting this region may be involved in the motion transmission from D1 to N domain. Mutating the residues in middle and C-terminal region of the N-D1 linker increases the basal ATPase activity, indicating it may play a role in autoinhibiting NSF activity until it encounters SNARE/α-SNAP complex substrate. Moreover, mutations at the C-terminal sequence GIGG exhibit completely abolished or severely reduced activities of the substrate binding, suggesting that the flexibility of N-D1 linker is critical for the movement of the N domain that is required for the substrate binding. Taken together, these data suggest that the whole N-D1 linker is critical for the biological function of NSF to disassemble SNARE complex substrate with different regions responsible for different roles.
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Affiliation(s)
- Cui-Cui Liu
- State Key Laboratory of Biomembrane and Membrane Biotechnology, Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China
| | - Shan Sun
- State Key Laboratory of Biomembrane and Membrane Biotechnology, Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China
- * E-mail: (SS); (SFS)
| | - Sen-Fang Sui
- State Key Laboratory of Biomembrane and Membrane Biotechnology, Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China
- * E-mail: (SS); (SFS)
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Belluzzi E, Greggio E, Piccoli G. Presynaptic dysfunction in Parkinson's disease: a focus on LRRK2. Biochem Soc Trans 2012; 40:1111-1116. [PMID: 22988874 DOI: 10.1042/bst20120124] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/01/2023]
Abstract
PD (Parkinson's disease) is a common neurodegenerative disease clinically characterized by bradykinesia, rigidity and resting tremor. Recent studies have proposed that synaptic dysfunction, implicated in numerous studies of animal models of PD, might be a key factor in PD. The molecular defects that lead to PD progression might be hidden at the presynaptic neuron: in fact accumulating evidence has shown that the majority of the genes linked to PD play a critical role at the presynaptic site. In the present paper, we focus on the presynaptic function of LRRK2 (leucine-rich repeat kinase 2), a protein that mutated represents the main genetic cause of familial PD described to date. Neurotransmission relies on proper presynaptic vesicle trafficking; defects in this process, variation in dopamine flow and alteration of presynaptic plasticity have been reported in several animal models of LRRK2 mutations. Furthermore, impaired dopamine turnover has been described in presymptomatic LRRK2 PD patients. Thus, given the pathological events occurring at the synapses of PD patients, the presynaptic site may represent a promising target for early diagnostic therapeutic intervention.
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Affiliation(s)
- Elisa Belluzzi
- Department of Biology, University of Padova, Via Ugo Bassi 58/B, Padua, Italy
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42
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Machado-Pinilla R, Liger D, Leulliot N, Meier UT. Mechanism of the AAA+ ATPases pontin and reptin in the biogenesis of H/ACA RNPs. RNA (NEW YORK, N.Y.) 2012; 18:1833-45. [PMID: 22923768 PMCID: PMC3446707 DOI: 10.1261/rna.034942.112] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
The AAA+ ATPases pontin and reptin function in a staggering array of cellular processes including chromatin remodeling, transcriptional regulation, DNA damage repair, and assembly of macromolecular complexes, such as RNA polymerase II and small nucleolar (sno) RNPs. However, the molecular mechanism for all of these AAA+ ATPase associated activities is unknown. Here we document that, during the biogenesis of H/ACA RNPs (including telomerase), the assembly factor SHQ1 holds the pseudouridine synthase NAP57/dyskerin in a viselike grip, and that pontin and reptin (as components of the R2TP complex) are required to pry NAP57 from SHQ1. Significantly, the NAP57 domain captured by SHQ1 harbors most mutations underlying X-linked dyskeratosis congenita (X-DC) implicating the interface between the two proteins as a target of this bone marrow failure syndrome. Homing in on the essential first steps of H/ACA RNP biogenesis, our findings provide the first insight into the mechanism of action of pontin and reptin in the assembly of macromolecular complexes.
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Affiliation(s)
- Rosario Machado-Pinilla
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, New York 10461, USA
| | - Dominique Liger
- Institut de Biochimie et de Biophysique Moléculaire et Cellulaire, Université de Paris-Sud, CNRS-UMR8619, IFR115, 91405 Orsay Cedex, France
| | - Nicolas Leulliot
- Laboratoire de Cristallographie et RMN Biologiques, UMR CNRS 8015, Université Paris Descartes, Sorbonne Paris Cité, Faculté des Sciences Pharmaceutiques et Biologiques, 75006 Paris, France
| | - U. Thomas Meier
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, New York 10461, USA
- Corresponding authorE-mail
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43
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Multiple roles for the actin cytoskeleton during regulated exocytosis. Cell Mol Life Sci 2012; 70:2099-121. [PMID: 22986507 DOI: 10.1007/s00018-012-1156-5] [Citation(s) in RCA: 135] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2012] [Revised: 08/28/2012] [Accepted: 08/30/2012] [Indexed: 01/01/2023]
Abstract
Regulated exocytosis is the main mechanism utilized by specialized secretory cells to deliver molecules to the cell surface by virtue of membranous containers (i.e., secretory vesicles). The process involves a series of highly coordinated and sequential steps, which include the biogenesis of the vesicles, their delivery to the cell periphery, their fusion with the plasma membrane, and the release of their content into the extracellular space. Each of these steps is regulated by the actin cytoskeleton. In this review, we summarize the current knowledge regarding the involvement of actin and its associated molecules during each of the exocytic steps in vertebrates, and suggest that the overall role of the actin cytoskeleton during regulated exocytosis is linked to the architecture and the physiology of the secretory cells under examination. Specifically, in neurons, neuroendocrine, endocrine, and hematopoietic cells, which contain small secretory vesicles that undergo rapid exocytosis (on the order of milliseconds), the actin cytoskeleton plays a role in pre-fusion events, where it acts primarily as a functional barrier and facilitates docking. In exocrine and other secretory cells, which contain large secretory vesicles that undergo slow exocytosis (seconds to minutes), the actin cytoskeleton plays a role in post-fusion events, where it regulates the dynamics of the fusion pore, facilitates the integration of the vesicles into the plasma membrane, provides structural support, and promotes the expulsion of large cargo molecules.
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44
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Nicholson SJ, Hartson SD, Puterka GJ. Proteomic analysis of secreted saliva from Russian Wheat Aphid (Diuraphis noxia Kurd.) biotypes that differ in virulence to wheat. J Proteomics 2012; 75:2252-68. [DOI: 10.1016/j.jprot.2012.01.031] [Citation(s) in RCA: 120] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2011] [Revised: 01/03/2012] [Accepted: 01/27/2012] [Indexed: 01/21/2023]
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45
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Chang LF, Chen S, Liu CC, Pan X, Jiang J, Bai XC, Xie X, Wang HW, Sui SF. Structural characterization of full-length NSF and 20S particles. Nat Struct Mol Biol 2012; 19:268-75. [PMID: 22307055 DOI: 10.1038/nsmb.2237] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2011] [Accepted: 12/20/2011] [Indexed: 11/09/2022]
Abstract
The 20S particle, which is composed of the N-ethylmaleimide-sensitive factor (NSF), soluble NSF attachment proteins (SNAPs) and the SNAP receptor (SNARE) complex, has an essential role in intracellular vesicle fusion events. Using single-particle cryo-EM and negative stain EM, we reconstructed four related three-dimensional structures: Chinese hamster NSF hexamer in the ATPγS, ADP-AlFx and ADP states, and the 20S particle. These structures reveal a parallel arrangement between the D1 and D2 domains of the hexameric NSF and characterize the nucleotide-dependent conformational changes in NSF. The structure of the 20S particle shows that it holds the SNARE complex at two interaction interfaces around the C terminus and N-terminal half of the SNARE complex, respectively. These findings provide insight into the molecular mechanism underlying disassembly of the SNARE complex by NSF.
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Affiliation(s)
- Lei-Fu Chang
- State Key Laboratory of Biomembrane and Membrane Biotechnology, Tsinghua University, Beijing, China
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46
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Moeller A, Zhao C, Fried MG, Wilson-Kubalek EM, Carragher B, Whiteheart SW. Nucleotide-dependent conformational changes in the N-Ethylmaleimide Sensitive Factor (NSF) and their potential role in SNARE complex disassembly. J Struct Biol 2012; 177:335-43. [PMID: 22245547 DOI: 10.1016/j.jsb.2011.12.018] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2011] [Revised: 12/28/2011] [Accepted: 12/29/2011] [Indexed: 11/25/2022]
Abstract
Homohexameric, N-Ethylmaleimide Sensitive Factor (NSF) disassembles Soluble NSF Attachment Protein Receptor (SNARE) complexes after membrane fusion, an essential step in vesicular trafficking. NSF contains three domains (NSF-N, NSF-D1, and NSF-D2), each contributing to activity. We combined electron microscopic (EM) analysis, analytical ultracentrifugation (AU) and functional mutagenesis to visualize NSF's ATPase cycle. 3D density maps show that NSF-D2 remains stable, whereas NSF-N undergoes large conformational changes. NSF-Ns splay out perpendicular to the ADP-bound hexamer and twist upwards upon ATP binding, producing a more compact structure. These conformations were confirmed by hydrodynamic, AU measurements: NSF-ATP sediments faster with a lower frictional ratio (f/f(0)). Hydrodynamic analyses of NSF mutants, with specific functional defects, define the structures underlying these conformational changes. Mapping mutations onto our 3D models allows interpretation of the domain movement and suggests a mechanism for NSF binding to and disassembly of SNARE complexes.
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Affiliation(s)
- Arne Moeller
- The Department of Cell Biology, The Scripps Research Institute, La Jolla, CA, USA
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