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Wang S, Li Y, Gong J, Ye S, Yang X, Zhang R, Ma C. Munc18 and Munc13 serve as a functional template to orchestrate neuronal SNARE complex assembly. Nat Commun 2019; 10:69. [PMID: 30622273 PMCID: PMC6325239 DOI: 10.1038/s41467-018-08028-6] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Accepted: 12/12/2018] [Indexed: 11/30/2022] Open
Abstract
The transition of the Munc18-1/syntaxin-1 complex to the SNARE complex, a key step involved in exocytosis, is regulated by Munc13-1, SNAP-25 and synaptobrevin-2, but the underlying mechanism remains elusive. Here, we identify an interaction between Munc13-1 and the membrane-proximal linker region of synaptobrevin-2, and reveal its essential role in transition and exocytosis. Upon this interaction, Munc13-1 not only recruits synaptobrevin-2-embedded vesicles to the target membrane but also renders the synaptobrevin-2 SNARE motif more accessible to the Munc18-1/syntaxin-1 complex. Afterward, the entry of SNAP-25 leads to a half-zippered SNARE assembly, which eventually dissociates the Munc18-1/syntaxin-1 complex to complete SNARE complex formation. Our data suggest that Munc18-1 and Munc13-1 together serve as a functional template to orchestrate SNARE complex assembly. Synaptic exocytosis depends on formation of the SNARE complex but its assembly mechanism is still under debate. Here, the authors identify an interaction between Munc13-1 and synaptobrevin-2 that is critical for the transition of the Munc18-1/syntaxin-1 complex to the SNARE complex.
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Affiliation(s)
- Shen Wang
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, and the Collaborative Innovation Center for Brain Science, Huazhong University of Science and Technology, 430074, Wuhan, China
| | - Yun Li
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, and the Collaborative Innovation Center for Brain Science, Huazhong University of Science and Technology, 430074, Wuhan, China
| | - Jihong Gong
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, and the Collaborative Innovation Center for Brain Science, Huazhong University of Science and Technology, 430074, Wuhan, China
| | - Sheng Ye
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 100101, Beijing, China
| | - Xiaofei Yang
- Key Laboratory of Cognitive Science, Hubei Key Laboratory of Medical Information Analysis and Tumor Diagnosis and Treatment, Laboratory of Membrane Ion Channels and Medicine, College of Biomedical Engineering, South-Central University for Nationalities, 430074, Wuhan, China
| | - Rongguang Zhang
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 100101, Beijing, China.,National Center for Protein Science Shanghai, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Science, Chinese Academy of Sciences, 201203, Shanghai, China
| | - Cong Ma
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, and the Collaborative Innovation Center for Brain Science, Huazhong University of Science and Technology, 430074, Wuhan, China.
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Schatton A, Agoro J, Mardink J, Leboulle G, Scharff C. Identification of the neurotransmitter profile of AmFoxP expressing neurons in the honeybee brain using double-label in situ hybridization. BMC Neurosci 2018; 19:69. [PMID: 30400853 PMCID: PMC6219247 DOI: 10.1186/s12868-018-0469-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 10/29/2018] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND FoxP transcription factors play crucial roles for the development and function of vertebrate brains. In humans the neurally expressed FOXPs, FOXP1, FOXP2, and FOXP4 are implicated in cognition, including language. Neural FoxP expression is specific to particular brain regions but FoxP1, FoxP2 and FoxP4 are not limited to a particular neuron or neurotransmitter type. Motor- or sensory activity can regulate FoxP2 expression, e.g. in the striatal nucleus Area X of songbirds and in the auditory thalamus of mice. The DNA-binding domain of FoxP proteins is highly conserved within metazoa, raising the possibility that cellular functions were preserved across deep evolutionary time. We have previously shown in bee brains that FoxP is expressed in eleven specific neuron populations, seven tightly packed clusters and four loosely arranged groups. RESULTS The present study examined the co-expression of honeybee FoxP (AmFoxP) with markers for glutamatergic, GABAergic, cholinergic and monoaminergic transmission. We found that AmFoxP could co-occur with any one of those markers. Interestingly, AmFoxP clusters and AmFoxP groups differed with respect to homogeneity of marker co-expression; within a cluster, all neurons co-expressed the same neurotransmitter marker, within a group co-expression varied. We also assessed qualitatively whether age or housing conditions providing different sensory and motor experiences affected the AmFoxP neuron populations, but found no differences. CONCLUSIONS Based on the neurotransmitter homogeneity we conclude that AmFoxP neurons within the clusters might have a common projection and function whereas the AmFoxP groups are more diverse and could be further sub-divided. The obtained information about the neurotransmitters co-expressed in the AmFoxP neuron populations facilitated the search of similar neurons described in the literature. These comparisons revealed e.g. a possible function of AmFoxP neurons in the central complex. Our findings provide opportunities to focus future functional studies on invertebrate FoxP expressing neurons. In a broader context, our data will contribute to the ongoing efforts to discern in which cases relationships between molecular and phenotypic signatures are linked evolutionary.
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Affiliation(s)
- Adriana Schatton
- Department of Animal Behavior, Freie Universität Berlin, Takustraße 6, 14195 Berlin, Germany
| | - Julia Agoro
- Department of Animal Behavior, Freie Universität Berlin, Takustraße 6, 14195 Berlin, Germany
- Department of Neurobiology, Freie Universität Berlin, Königin-Luise-Straße 28-30, 14195 Berlin, Germany
| | - Janis Mardink
- Department of Animal Behavior, Freie Universität Berlin, Takustraße 6, 14195 Berlin, Germany
| | - Gérard Leboulle
- Department of Neurobiology, Freie Universität Berlin, Königin-Luise-Straße 28-30, 14195 Berlin, Germany
| | - Constance Scharff
- Department of Animal Behavior, Freie Universität Berlin, Takustraße 6, 14195 Berlin, Germany
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Ampah KK, Greaves J, Shun-Shion AS, Asnawi AW, Lidster JA, Chamberlain LH, Collins MO, Peden AA. S-acylation regulates the trafficking and stability of the unconventional Q-SNARE STX19. J Cell Sci 2018; 131:jcs.212498. [PMID: 30254024 DOI: 10.1242/jcs.212498] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Accepted: 09/17/2018] [Indexed: 12/19/2022] Open
Abstract
STX19 is an unusual Qa-SNARE as it lacks a C-terminal transmembrane domain. However, it is efficiently targeted to post-Golgi membranes. Here, we set out to determine the intracellular localisation of endogenous STX19 and elucidate the mechanism by which it is targeted to membranes. We have found that a pool of STX19 is localised to tubular recycling endosomes where it colocalises with MICAL-L1 and Rab8 (which has Rab8a and Rab8b forms). Using a combination of genetic, biochemical and cell-based approaches, we have identified that STX19 is S-acylated at its C-terminus and is a substrate for several Golgi-localised S-acyltransferases, suggesting that STX19 is initially S-acylated at the Golgi before trafficking to the plasma membrane and endosomes. Surprisingly, we have found that S-acylation is a key determinant in targeting STX19 to tubular recycling endosomes, suggesting that S-acylation may play a general role in directing proteins to this compartment. In addition, S-acylation also protects STX19 from proteosomal degradation, indicating that S-acylation regulates the function of STX19 at multiple levels.This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Khamal K Ampah
- Department of Biomedical Science, Centre for Membrane Interactions and Dynamics, University of Sheffield, Firth Court, Sheffield S10 2TN, UK
| | - Jennifer Greaves
- Faculty of Health and Life Sciences, Coventry University, Science and Health Building, 20 Whitefriars Street, Coventry CV1 2DS, UK
| | - Amber S Shun-Shion
- Department of Biomedical Science, Centre for Membrane Interactions and Dynamics, University of Sheffield, Firth Court, Sheffield S10 2TN, UK
| | - Asral W Asnawi
- Department of Biomedical Science, Centre for Membrane Interactions and Dynamics, University of Sheffield, Firth Court, Sheffield S10 2TN, UK.,Faculty of Medicine and Health Sciences, University Sains Islam Malaysia, 55700 Kuala Lumpur, Malaysia
| | - Jessica A Lidster
- Department of Biomedical Science, Centre for Membrane Interactions and Dynamics, University of Sheffield, Firth Court, Sheffield S10 2TN, UK
| | - Luke H Chamberlain
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow G4 0RE, UK
| | - Mark O Collins
- Department of Biomedical Science, Centre for Membrane Interactions and Dynamics, University of Sheffield, Firth Court, Sheffield S10 2TN, UK.,Faculty of Science, Mass Spectrometry Centre, University of Sheffield, Brook Hill Road, Sheffield S3 7HF, UK
| | - Andrew A Peden
- Department of Biomedical Science, Centre for Membrane Interactions and Dynamics, University of Sheffield, Firth Court, Sheffield S10 2TN, UK
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Khurana GK, Vishwakarma P, Puri N, Lynn AM. Phylogenetic Analysis of the vesicular fusion SNARE machinery revealing its functional divergence across Eukaryotes. Bioinformation 2018; 14:361-368. [PMID: 30262973 PMCID: PMC6143360 DOI: 10.6026/97320630014361] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Revised: 07/12/2018] [Accepted: 07/30/2018] [Indexed: 12/23/2022] Open
Abstract
Proteins of the SNARE (Soluble N-ethylmaleimide-sensitive factor attachment protein receptors) family play a significant role in all
vesicular fusion events involved in endocytic and exocytic pathways. These proteins act as molecular machines that assemble into tight
four-helix bundle complex, bridging the opposing membranes into close proximity forming membrane fusion. Almost all SNARE
proteins share a 53 amino acid coiled-coil domain, which is mostly linked to the transmembrane domain at the C-terminal end. Despite
significant variations between SNARE sequences across species, the SNARE mediated membrane fusion is evolutionary conserved in
all eukaryotes. It is of interest to compare the functional divergence of SNARE proteins across various eukaryotic groups during
evolution. Here, we report an exhaustive phylogeny of the SNARE proteins retrieved from SNARE database including plants, animals,
fungi and protists. The Initial phylogeny segregated SNARE protein sequences into five well-supported clades Qa, Qb, Qc, Qbc and R
reflective of their positions in the four-helix SNARE complex. Further to improve resolution the Qa, Qb, Qc and R family specific trees
were reconstructed, each of these were further segregated into organelle specific clades at first and later diverged into lineage specific
subgroups. This revealed that most of the SNARE orthologs are conserved at subcellular locations or at trafficking pathways across
various species during eukaryotic evolution. The paralogous expansion in SNARE repertoire was observed at metazoans (animals) and
plants independently during eukaryotic evolution. However, results also show that the multi-cellular and saprophytic fungi have
limited SNAREs.
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Affiliation(s)
- Gagandeep K Khurana
- School of Life Sciences, Jawaharlal Nehru University, New Delhi, India- 110067
| | - Poonam Vishwakarma
- School of Computational and Integrative Sciences, Jawaharlal Nehru University, New Delhi, India-110067
| | - Niti Puri
- School of Life Sciences, Jawaharlal Nehru University, New Delhi, India- 110067
| | - Andrew Michael Lynn
- School of Computational and Integrative Sciences, Jawaharlal Nehru University, New Delhi, India-110067
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Muro S. Alterations in Cellular Processes Involving Vesicular Trafficking and Implications in Drug Delivery. Biomimetics (Basel) 2018; 3:biomimetics3030019. [PMID: 31105241 PMCID: PMC6352689 DOI: 10.3390/biomimetics3030019] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2018] [Revised: 07/09/2018] [Accepted: 07/10/2018] [Indexed: 12/31/2022] Open
Abstract
Endocytosis and vesicular trafficking are cellular processes that regulate numerous functions required to sustain life. From a translational perspective, they offer avenues to improve the access of therapeutic drugs across cellular barriers that separate body compartments and into diseased cells. However, the fact that many factors have the potential to alter these routes, impacting our ability to effectively exploit them, is often overlooked. Altered vesicular transport may arise from the molecular defects underlying the pathological syndrome which we aim to treat, the activity of the drugs being used, or side effects derived from the drug carriers employed. In addition, most cellular models currently available do not properly reflect key physiological parameters of the biological environment in the body, hindering translational progress. This article offers a critical overview of these topics, discussing current achievements, limitations and future perspectives on the use of vesicular transport for drug delivery applications.
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Affiliation(s)
- Silvia Muro
- Institute for Bioscience and Biotechnology Research and Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742, USA.
- Catalan Institution for Research and Advanced Studies (ICREA), 08010 Barcelona, Spain.
- Institute for Bioengineering of Catalonia (IBEC) of the Barcelona Institute of Science and Technology (BIST), 08028 Barcelona, Spain.
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The remembrance of the things past: Conserved signalling pathways link protozoa to mammalian nervous system. Cell Calcium 2018; 73:25-39. [DOI: 10.1016/j.ceca.2018.04.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Revised: 04/01/2018] [Accepted: 04/01/2018] [Indexed: 12/13/2022]
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Abstract
Platelet granules are unique among secretory vesicles in both their content and their life cycle. Platelets contain three major granule types—dense granules, α-granules, and lysosomes—although other granule types have been reported. Dense granules and α-granules are the most well-studied and the most physiologically important. Platelet granules are formed in large, multilobulated cells, termed megakaryocytes, prior to transport into platelets. The biogenesis of dense granules and α-granules involves common but also distinct pathways. Both are formed from the
trans-Golgi network and early endosomes and mature in multivesicular bodies, but the formation of dense granules requires trafficking machinery different from that of α-granules. Following formation in the megakaryocyte body, both granule types are transported through and mature in long proplatelet extensions prior to the release of nascent platelets into the bloodstream. Granules remain stored in circulating platelets until platelet activation triggers the exocytosis of their contents. Soluble
N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins, located on both the granules and target membranes, provide the mechanical energy that enables membrane fusion during both granulogenesis and exocytosis. The function of these core fusion engines is controlled by SNARE regulators, which direct the site, timing, and extent to which these SNAREs interact and consequently the resulting membrane fusion. In this review, we assess new developments in the study of platelet granules, from their generation to their exocytosis.
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Affiliation(s)
- Anish Sharda
- Division of Hemostasis and Thrombosis, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, USA
| | - Robert Flaumenhaft
- Division of Hemostasis and Thrombosis, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, USA
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59
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Diverse exocytic pathways for mast cell mediators. Biochem Soc Trans 2018; 46:235-247. [PMID: 29472369 DOI: 10.1042/bst20170450] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Revised: 12/23/2017] [Accepted: 01/04/2018] [Indexed: 12/14/2022]
Abstract
Mast cells play pivotal roles in innate and adaptive immunities but are also culprits in allergy, autoimmunity, and cardiovascular diseases. Mast cells respond to environmental changes by initiating regulated exocytosis/secretion of various biologically active compounds called mediators (e.g. proteases, amines, and cytokines). Many of these mediators are stored in granules/lysosomes and rely on intricate degranulation processes for release. Mast cell stabilizers (e.g. sodium cromoglicate), which prevent such degranulation processes, have therefore been clinically employed to treat asthma and allergic rhinitis. However, it has become increasingly clear that different mast cell diseases often involve multiple mediators that rely on overlapping but distinct mechanisms for release. This review illustrates existing evidence that highlights the diverse exocytic pathways in mast cells. We also discuss strategies to delineate these pathways so as to identify unique molecular components which could serve as new drug targets for more effective and specific treatments against mast cell-related diseases.
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Völker JM, Dergai M, Abriata LA, Mingard Y, Ysselstein D, Krainc D, Dal Peraro M, Fischer von Mollard G, Fasshauer D, Koliwer J, Schwake M. Functional assays for the assessment of the pathogenicity of variants of GOSR2, an ER-to-Golgi SNARE involved in progressive myoclonus epilepsies. Dis Model Mech 2017; 10:1391-1398. [PMID: 28982678 PMCID: PMC5769602 DOI: 10.1242/dmm.029132] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Accepted: 10/02/2017] [Indexed: 11/20/2022] Open
Abstract
Progressive myoclonus epilepsies (PMEs) are inherited disorders characterized by myoclonus, generalized tonic-clonic seizures, and ataxia. One of the genes that is associated with PME is the ER-to-Golgi Qb-SNARE GOSR2, which forms a SNARE complex with syntaxin-5, Bet1 and Sec22b. Most PME patients are homozygous for a p.Gly144Trp mutation and develop similar clinical presentations. Recently, a patient who was compound heterozygous for p.Gly144Trp and a previously unseen p.Lys164del mutation was identified. Because this patient presented with a milder disease phenotype, we hypothesized that the p.Lys164del mutation may be less severe compared to p.Gly144Trp. To characterize the effect of the p.Gly144Trp and p.Lys164del mutations, both of which are present in the SNARE motif of GOSR2, we examined the corresponding mutations in the yeast ortholog Bos1. Yeasts expressing the orthologous mutants in Bos1 showed impaired growth, suggesting a partial loss of function, which was more severe for the Bos1 p.Gly176Trp mutation. Using anisotropy and gel filtration, we report that Bos1 p.Gly176Trp and p.Arg196del are capable of complex formation, but with partly reduced activity. Molecular dynamics (MD) simulations showed that the hydrophobic core, which triggers SNARE complex formation, is compromised due to the glycine-to-tryptophan substitution in both GOSR2 and Bos1. In contrast, the deletion of residue p.Lys164 (or p.Arg196del in Bos1) interferes with the formation of hydrogen bonds between GOSR2 and syntaxin-5. Despite these perturbations, all SNARE complexes stayed intact during longer simulations. Thus, our data suggest that the milder course of disease in compound heterozygous PME is due to less severe impairment of the SNARE function. Summary: Mutations in the Qb-SNARE GOSR2 cause progressive myoclonus epilepsies. The authors report the effect of two mutations on SNARE function to investigate their correlation with progression and severity of disease.
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Affiliation(s)
- Jörn M Völker
- Biochemistry III/Faculty of Chemistry, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany
| | - Mykola Dergai
- Department of Fundamental Neurosciences, University of Lausanne, Rue du Bugnon 9, 1005 Lausanne, Switzerland
| | - Luciano A Abriata
- Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland.,Swiss Institute of Bioinformatics (SIB), CH-1015 Lausanne, Switzerland
| | - Yves Mingard
- Department of Fundamental Neurosciences, University of Lausanne, Rue du Bugnon 9, 1005 Lausanne, Switzerland
| | - Daniel Ysselstein
- Department of Neurology, Northwestern University Feinberg School of Medicine, 303 East Chicago Avenue, 60611 Chicago, USA
| | - Dimitri Krainc
- Department of Neurology, Northwestern University Feinberg School of Medicine, 303 East Chicago Avenue, 60611 Chicago, USA
| | - Matteo Dal Peraro
- Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland.,Swiss Institute of Bioinformatics (SIB), CH-1015 Lausanne, Switzerland
| | | | - Dirk Fasshauer
- Department of Fundamental Neurosciences, University of Lausanne, Rue du Bugnon 9, 1005 Lausanne, Switzerland
| | - Judith Koliwer
- Biochemistry III/Faculty of Chemistry, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany
| | - Michael Schwake
- Biochemistry III/Faculty of Chemistry, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany .,Department of Neurology, Northwestern University Feinberg School of Medicine, 303 East Chicago Avenue, 60611 Chicago, USA
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Liebeskind BJ, Hofmann HA, Hillis DM, Zakon HH. Evolution of Animal Neural Systems. ANNUAL REVIEW OF ECOLOGY EVOLUTION AND SYSTEMATICS 2017. [DOI: 10.1146/annurev-ecolsys-110316-023048] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Nervous systems are among the most spectacular products of evolution. Their provenance and evolution have been of interest and often the subjects of intense debate since the late nineteenth century. The genomics era has provided researchers with a new set of tools with which to study the early evolution of neurons, and recent progress on the molecular evolution of the first neurons has been both exciting and frustrating. It has become increasingly obvious that genomic data are often insufficient to reconstruct complex phenotypes in deep evolutionary time because too little is known about how gene function evolves over deep time. Therefore, additional functional data across the animal tree are a prerequisite to a fuller understanding of cell evolution. To this end, we review the functional modules of neurons and the evolution of their molecular components, and we introduce the idea of hierarchical molecular evolution.
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Affiliation(s)
- Benjamin J. Liebeskind
- Center for Systems and Synthetic Biology, University of Texas at Austin, Austin, Texas 78712
- Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, Texas 78712
- Center for Computational Biology and Bioinformatics, University of Texas at Austin, Austin, Texas 78712
| | - Hans A. Hofmann
- Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, Texas 78712
- Center for Computational Biology and Bioinformatics, University of Texas at Austin, Austin, Texas 78712
- Department of Integrative Biology, University of Texas at Austin, Austin, Texas 78712
- Institute for Neuroscience, University of Texas at Austin, Austin, Texas 78712
| | - David M. Hillis
- Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, Texas 78712
- Center for Computational Biology and Bioinformatics, University of Texas at Austin, Austin, Texas 78712
- Department of Integrative Biology, University of Texas at Austin, Austin, Texas 78712
| | - Harold H. Zakon
- Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, Texas 78712
- Center for Computational Biology and Bioinformatics, University of Texas at Austin, Austin, Texas 78712
- Department of Integrative Biology, University of Texas at Austin, Austin, Texas 78712
- Department of Neuroscience, University of Texas at Austin, Austin, Texas 78712
- Institute for Neuroscience, University of Texas at Austin, Austin, Texas 78712
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Praschberger R, Lowe SA, Malintan NT, Giachello CNG, Patel N, Houlden H, Kullmann DM, Baines RA, Usowicz MM, Krishnakumar SS, Hodge JJL, Rothman JE, Jepson JEC. Mutations in Membrin/GOSR2 Reveal Stringent Secretory Pathway Demands of Dendritic Growth and Synaptic Integrity. Cell Rep 2017; 21:97-109. [PMID: 28978487 PMCID: PMC5640804 DOI: 10.1016/j.celrep.2017.09.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Revised: 08/17/2017] [Accepted: 09/01/2017] [Indexed: 11/16/2022] Open
Abstract
Mutations in the Golgi SNARE (SNAP [soluble NSF attachment protein] receptor) protein Membrin (encoded by the GOSR2 gene) cause progressive myoclonus epilepsy (PME). Membrin is a ubiquitous and essential protein mediating ER-to-Golgi membrane fusion. Thus, it is unclear how mutations in Membrin result in a disorder restricted to the nervous system. Here, we use a multi-layered strategy to elucidate the consequences of Membrin mutations from protein to neuron. We show that the pathogenic mutations cause partial reductions in SNARE-mediated membrane fusion. Importantly, these alterations were sufficient to profoundly impair dendritic growth in Drosophila models of GOSR2-PME. Furthermore, we show that Membrin mutations cause fragmentation of the presynaptic cytoskeleton coupled with transsynaptic instability and hyperactive neurotransmission. Our study highlights how dendritic growth is vulnerable even to subtle secretory pathway deficits, uncovers a role for Membrin in synaptic function, and provides a comprehensive explanatory basis for genotype-phenotype relationships in GOSR2-PME.
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Affiliation(s)
- Roman Praschberger
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, London, UK
| | - Simon A Lowe
- School of Physiology, Pharmacology, and Neuroscience, University of Bristol, Bristol, UK
| | - Nancy T Malintan
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, London, UK
| | - Carlo N G Giachello
- Faculty of Biology, Medicine, and Health, Division of Neuroscience & Experimental Psychology, Manchester Academic Health Science Centre, University of Manchester, Manchester, UK
| | - Nian Patel
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, London, UK
| | - Henry Houlden
- Department of Molecular Neuroscience, UCL Institute of Neurology, London, UK
| | - Dimitri M Kullmann
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, London, UK
| | - Richard A Baines
- Faculty of Biology, Medicine, and Health, Division of Neuroscience & Experimental Psychology, Manchester Academic Health Science Centre, University of Manchester, Manchester, UK
| | - Maria M Usowicz
- School of Physiology, Pharmacology, and Neuroscience, University of Bristol, Bristol, UK
| | - Shyam S Krishnakumar
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, London, UK; Department of Cell Biology, Yale School of Medicine, New Haven, CT, USA
| | - James J L Hodge
- School of Physiology, Pharmacology, and Neuroscience, University of Bristol, Bristol, UK
| | - James E Rothman
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, London, UK; Department of Cell Biology, Yale School of Medicine, New Haven, CT, USA
| | - James E C Jepson
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, London, UK.
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63
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Barlow LD, Dacks JB. Seeing the endomembrane system for the trees: Evolutionary analysis highlights the importance of plants as models for eukaryotic membrane-trafficking. Semin Cell Dev Biol 2017; 80:142-152. [PMID: 28939036 DOI: 10.1016/j.semcdb.2017.09.027] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2017] [Revised: 08/22/2017] [Accepted: 09/19/2017] [Indexed: 12/12/2022]
Abstract
Plant cells show many signs of a unique evolutionary history. This is seen in the system of intracellular organelles and vesicle transport pathways plants use to traffic molecular cargo. Bioinformatic and cell biological work in this area is beginning to tackle the question of how plant cells have evolved, and what this tells us about the evolution of other eukaryotes. Key protein families with membrane trafficking function, including Rabs, SNAREs, vesicle coat proteins, and ArfGAPs, show patterns of evolution that indicate both specialization and conservation in plants. These changes are accompanied by changes at the level of organelles and trafficking pathways between them. Major specializations include losses of several ancient Rabs, novel functions of many proteins, and apparent modification of trafficking in endocytosis and cytokinesis. Nevertheless, plants show extensive conservation of ancestral membrane trafficking genes, and conservation of their ancestral function in most duplicates. Moreover, plants have retained several ancient membrane trafficking genes lost in the evolution of animals and fungi. Considering this, plants such as Arabidopsis are highly valuable for investigating not only plant-specific aspects of membrane trafficking, but also general eukaryotic mechanisms.
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Affiliation(s)
- L D Barlow
- Department of Cell Biology, Faculty of Medicine and Dentistry, University of Alberta,5-31 Medical Sciences Building, Edmonton, Alberta, T6G 2H7, Canada
| | - J B Dacks
- Department of Cell Biology, Faculty of Medicine and Dentistry, University of Alberta,5-31 Medical Sciences Building, Edmonton, Alberta, T6G 2H7, Canada.
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64
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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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65
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Munc18a clusters SNARE-bearing liposomes prior to trans-SNARE zippering. Biochem J 2017; 474:3339-3354. [PMID: 28827281 DOI: 10.1042/bcj20170494] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Revised: 08/16/2017] [Accepted: 08/17/2017] [Indexed: 12/16/2022]
Abstract
Sec1-Munc18 (SM) proteins co-operate with SNAREs {SNAP [soluble NSF (N-ethylmaleimide-sensitive factor) attachment protein] receptors} to mediate membrane fusion in eukaryotic cells. Studies of Munc18a/Munc18-1/Stxbp1 in neurotransmission suggest that SM proteins accelerate fusion kinetics primarily by activating the partially zippered trans-SNARE complex. However, accumulating evidence has argued for additional roles for SM proteins in earlier steps in the fusion cascade. Here, we investigate the function of Munc18a in reconstituted exocytic reactions mediated by neuronal and non-neuronal SNAREs. We show that Munc18a plays a direct role in promoting proteoliposome clustering, underlying vesicle docking during exocytosis. In the three different fusion reactions examined, Munc18a-dependent clustering requires an intact N-terminal peptide (N-peptide) motif in syntaxin that mediates the binary interaction between syntaxin and Munc18a. Importantly, clustering is preserved under inhibitory conditions that abolish both trans-SNARE complex formation and lipid mixing, indicating that Munc18a promotes membrane clustering in a step that is independent of trans-SNARE zippering and activation.
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66
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Abstract
The evolution of a nervous system as a control system of the body's functions is a key innovation of animals. Its fundamental units are neurons, highly specialized cells dedicated to fast cell-cell communication. Neurons pass signals to other neurons, muscle cells, or gland cells at specialized junctions, the synapses, where transmitters are released from vesicles in a Ca2+-dependent fashion to activate receptors in the membrane of the target cell. Reconstructing the origins of neuronal communication out of a more simple process remains a central challenge in biology. Recent genomic comparisons have revealed that all animals, including the nerveless poriferans and placozoans, share a basic set of genes for neuronal communication. This suggests that the first animal, the Urmetazoan, was already endowed with neurosecretory cells that probably started to connect into neuronal networks soon afterward. Here, we discuss scenarios for this pivotal transition in animal evolution.
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Affiliation(s)
- Frederique Varoqueaux
- Département des Neurosciences Fondamentales, Université de Lausanne, Lausanne, CH-1005 Switzerland; ,
| | - Dirk Fasshauer
- Département des Neurosciences Fondamentales, Université de Lausanne, Lausanne, CH-1005 Switzerland; ,
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67
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Dhara M, Mohrmann R, Bruns D. v-SNARE function in chromaffin cells. Pflugers Arch 2017; 470:169-180. [PMID: 28887593 PMCID: PMC5748422 DOI: 10.1007/s00424-017-2066-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Revised: 08/28/2017] [Accepted: 08/29/2017] [Indexed: 01/04/2023]
Abstract
Vesicle fusion is elementary for intracellular trafficking and release of signal molecules, thus providing the basis for diverse forms of intercellular communication like hormonal regulation or synaptic transmission. A detailed characterization of the mechanisms underlying exocytosis is key to understand how the nervous system integrates information and generates appropriate responses to stimuli. The machinery for vesicular release employs common molecular players in different model systems including neuronal and neuroendocrine cells, in particular members of the SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptors) protein family, Sec1/Munc18-like proteins, and other accessory factors. To achieve temporal precision and speed, excitable cells utilize specialized regulatory proteins like synaptotagmin and complexin, whose interplay putatively synchronizes vesicle fusion and enhances stimulus-secretion coupling. In this review, we aim to highlight recent progress and emerging views on the molecular mechanisms, by which constitutively forming SNAREpins are organized in functional, tightly regulated units for synchronized release. Specifically, we will focus on the role of vesicle associated membrane proteins, also referred to as vesicular SNAREs, in fusion and rapid cargo discharge. We will further discuss the functions of SNARE regulators during exocytosis and focus on chromaffin cell as a model system of choice that allows for detailed structure-function analyses and direct measurements of vesicle fusion under precise control of intracellular [Ca]i.
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Affiliation(s)
- Madhurima Dhara
- Molecular Neurophysiology, CIPMM, Medical Faculty, Saarland University, 66421, Homburg/Saar, Germany
| | - Ralf Mohrmann
- Zentrum für Human- und Molekularbiologie, Saarland University, 66421, Homburg/Saar, Germany
| | - Dieter Bruns
- Molecular Neurophysiology, CIPMM, Medical Faculty, Saarland University, 66421, Homburg/Saar, Germany.
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68
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Müller A, Mziaut H, Neukam M, Knoch KP, Solimena M. A 4D view on insulin secretory granule turnover in the β-cell. Diabetes Obes Metab 2017; 19 Suppl 1:107-114. [PMID: 28880479 DOI: 10.1111/dom.13015] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Revised: 05/16/2017] [Accepted: 05/17/2017] [Indexed: 01/31/2023]
Abstract
Insulin secretory granule (SG) turnover consists of several highly regulated processes allowing for proper β-cell function and insulin secretion. Besides the spatial distribution of insulin SGs, their age has great impact on the likelihood of their secretion and their behaviour within the β-cell. While quantitative measurements performed decades ago demonstrated the preferential secretion of young insulin, new experimental approaches aim to investigate insulin ageing at the granular level. Live-cell imaging, automated image analysis and correlative light and electron microscopy have fostered knowledge of age-defined insulin SG dynamics, their interaction with the cytoskeleton and ultrastructural features. Here, we review our recent work in regards to the connection between insulin SG age, SG dynamics, intracellular location and interaction with other proteins.
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Affiliation(s)
- Andreas Müller
- Molecular Diabetology, University Hospital and Faculty of Medicine Carl Gustav Carus, TU Dresden, Dresden, Germany
- Paul Langerhans Institute Dresden (PLID) of the Helmholtz Center Munich, University Hospital Carl Gustav Carus and Faculty of Medicine of the TU Dresden, Dresden, Germany
- German Center for Diabetes Research (DZD e.V.), Neuherberg, Germany
| | - Hassan Mziaut
- Molecular Diabetology, University Hospital and Faculty of Medicine Carl Gustav Carus, TU Dresden, Dresden, Germany
- Paul Langerhans Institute Dresden (PLID) of the Helmholtz Center Munich, University Hospital Carl Gustav Carus and Faculty of Medicine of the TU Dresden, Dresden, Germany
- German Center for Diabetes Research (DZD e.V.), Neuherberg, Germany
| | - Martin Neukam
- Molecular Diabetology, University Hospital and Faculty of Medicine Carl Gustav Carus, TU Dresden, Dresden, Germany
- Paul Langerhans Institute Dresden (PLID) of the Helmholtz Center Munich, University Hospital Carl Gustav Carus and Faculty of Medicine of the TU Dresden, Dresden, Germany
- German Center for Diabetes Research (DZD e.V.), Neuherberg, Germany
| | - Klaus-Peter Knoch
- Molecular Diabetology, University Hospital and Faculty of Medicine Carl Gustav Carus, TU Dresden, Dresden, Germany
- Paul Langerhans Institute Dresden (PLID) of the Helmholtz Center Munich, University Hospital Carl Gustav Carus and Faculty of Medicine of the TU Dresden, Dresden, Germany
- German Center for Diabetes Research (DZD e.V.), Neuherberg, Germany
| | - Michele Solimena
- Molecular Diabetology, University Hospital and Faculty of Medicine Carl Gustav Carus, TU Dresden, Dresden, Germany
- Paul Langerhans Institute Dresden (PLID) of the Helmholtz Center Munich, University Hospital Carl Gustav Carus and Faculty of Medicine of the TU Dresden, Dresden, Germany
- German Center for Diabetes Research (DZD e.V.), Neuherberg, Germany
- Max Planck Institute of Molecular Cell Biology and Genetics (MPI-CBG), Dresden, Germany
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69
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Plattner H. Evolutionary Cell Biology of Proteins from Protists to Humans and Plants. J Eukaryot Microbiol 2017; 65:255-289. [PMID: 28719054 DOI: 10.1111/jeu.12449] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Revised: 07/04/2017] [Accepted: 07/07/2017] [Indexed: 01/10/2023]
Abstract
During evolution, the cell as a fine-tuned machine had to undergo permanent adjustments to match changes in its environment, while "closed for repair work" was not possible. Evolution from protists (protozoa and unicellular algae) to multicellular organisms may have occurred in basically two lineages, Unikonta and Bikonta, culminating in mammals and angiosperms (flowering plants), respectively. Unicellular models for unikont evolution are myxamoebae (Dictyostelium) and increasingly also choanoflagellates, whereas for bikonts, ciliates are preferred models. Information accumulating from combined molecular database search and experimental verification allows new insights into evolutionary diversification and maintenance of genes/proteins from protozoa on, eventually with orthologs in bacteria. However, proteins have rarely been followed up systematically for maintenance or change of function or intracellular localization, acquirement of new domains, partial deletion (e.g. of subunits), and refunctionalization, etc. These aspects are discussed in this review, envisaging "evolutionary cell biology." Protozoan heritage is found for most important cellular structures and functions up to humans and flowering plants. Examples discussed include refunctionalization of voltage-dependent Ca2+ channels in cilia and replacement by other types during evolution. Altogether components serving Ca2+ signaling are very flexible throughout evolution, calmodulin being a most conservative example, in contrast to calcineurin whose catalytic subunit is lost in plants, whereas both subunits are maintained up to mammals for complex functions (immune defense and learning). Domain structure of R-type SNAREs differs in mono- and bikonta, as do Ca2+ -dependent protein kinases. Unprecedented selective expansion of the subunit a which connects multimeric base piece and head parts (V0, V1) of H+ -ATPase/pump may well reflect the intriguing vesicle trafficking system in ciliates, specifically in Paramecium. One of the most flexible proteins is centrin when its intracellular localization and function throughout evolution is traced. There are many more examples documenting evolutionary flexibility of translation products depending on requirements and potential for implantation within the actual cellular context at different levels of evolution. From estimates of gene and protein numbers per organism, it appears that much of the basic inventory of protozoan precursors could be transmitted to highest eukaryotic levels, with some losses and also with important additional "inventions."
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Affiliation(s)
- Helmut Plattner
- Department of Biology, University of Konstanz, P. O. Box M625, Konstanz, 78457, Germany
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70
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Shukla A, Bhattacharyya A, Kuppusamy L, Srivas M, Thattai M. Discovering vesicle traffic network constraints by model checking. PLoS One 2017; 12:e0180692. [PMID: 28683137 PMCID: PMC5500374 DOI: 10.1371/journal.pone.0180692] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Accepted: 06/07/2017] [Indexed: 11/18/2022] Open
Abstract
A eukaryotic cell contains multiple membrane-bound compartments. Transport vesicles move cargo between these compartments, just as trucks move cargo between warehouses. These processes are regulated by specific molecular interactions, as summarized in the Rothman-Schekman-Sudhof model of vesicle traffic. The whole structure can be represented as a transport graph: each organelle is a node, and each vesicle route is a directed edge. What constraints must such a graph satisfy, if it is to represent a biologically realizable vesicle traffic network? Graph connectedness is an informative feature: 2-connectedness is necessary and sufficient for mass balance, but stronger conditions are required to ensure correct molecular specificity. Here we use Boolean satisfiability (SAT) and model checking as a framework to discover and verify graph constraints. The poor scalability of SAT model checkers often prevents their broad application. By exploiting the special structure of the problem, we scale our model checker to vesicle traffic systems with reasonably large numbers of molecules and compartments. This allows us to test a range of hypotheses about graph connectivity, which can later be proved in full generality by other methods.
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Affiliation(s)
- Ankit Shukla
- School of Computer Science and Engineering, Vellore Institute of Technology, Vellore, India
| | - Arnab Bhattacharyya
- Department of Computer Science and Automation, Indian Institute of Science, Bengaluru, India
| | - Lakshmanan Kuppusamy
- School of Computer Science and Engineering, Vellore Institute of Technology, Vellore, India
| | | | - Mukund Thattai
- Simons Centre for the Study of Living Machines, National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bengaluru, India
- * E-mail:
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71
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The birth of the synapse. Brain Struct Funct 2017; 222:3369-3374. [DOI: 10.1007/s00429-017-1459-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Accepted: 06/06/2017] [Indexed: 10/19/2022]
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72
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Wragg RT, Parisotto DA, Li Z, Terakawa MS, Snead D, Basu I, Weinstein H, Eliezer D, Dittman JS. Evolutionary Divergence of the C-terminal Domain of Complexin Accounts for Functional Disparities between Vertebrate and Invertebrate Complexins. Front Mol Neurosci 2017; 10:146. [PMID: 28603484 PMCID: PMC5445133 DOI: 10.3389/fnmol.2017.00146] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Accepted: 04/30/2017] [Indexed: 12/19/2022] Open
Abstract
Complexin is a critical presynaptic protein that regulates both spontaneous and calcium-triggered neurotransmitter release in all synapses. Although the SNARE-binding central helix of complexin is highly conserved and required for all known complexin functions, the remainder of the protein has profoundly diverged across the animal kingdom. Striking disparities in complexin inhibitory activity are observed between vertebrate and invertebrate complexins but little is known about the source of these differences or their relevance to the underlying mechanism of complexin regulation. We found that mouse complexin 1 (mCpx1) failed to inhibit neurotransmitter secretion in Caenorhabditis elegans neuromuscular junctions lacking the worm complexin 1 (CPX-1). This lack of inhibition stemmed from differences in the C-terminal domain (CTD) of mCpx1. Previous studies revealed that the CTD selectively binds to highly curved membranes and directs complexin to synaptic vesicles. Although mouse and worm complexin have similar lipid binding affinity, their last few amino acids differ in both hydrophobicity and in lipid binding conformation, and these differences strongly impacted CPX-1 inhibitory function. Moreover, function was not maintained if a critical amphipathic helix in the worm CPX-1 CTD was replaced with the corresponding mCpx1 amphipathic helix. Invertebrate complexins generally shared more C-terminal similarity with vertebrate complexin 3 and 4 isoforms, and the amphipathic region of mouse complexin 3 significantly restored inhibitory function to worm CPX-1. We hypothesize that the CTD of complexin is essential in conferring an inhibitory function to complexin, and that this inhibitory activity has been attenuated in the vertebrate complexin 1 and 2 isoforms. Thus, evolutionary changes in the complexin CTD differentially shape its synaptic role across phylogeny.
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Affiliation(s)
- Rachel T Wragg
- Department of Biochemistry, Weill Cornell Medical College, New YorkNY, United States
| | - Daniel A Parisotto
- Department of Biochemistry, Weill Cornell Medical College, New YorkNY, United States
| | - Zhenlong Li
- Department of Physiology and Biophysics, Weill Cornell Medical College, New YorkNY, United States
| | - Mayu S Terakawa
- Department of Biochemistry, Weill Cornell Medical College, New YorkNY, United States
| | - David Snead
- Department of Biochemistry, Weill Cornell Medical College, New YorkNY, United States
| | - Ishani Basu
- Department of Biochemistry, Weill Cornell Medical College, New YorkNY, United States
| | - Harel Weinstein
- Department of Physiology and Biophysics, Weill Cornell Medical College, New YorkNY, United States.,Institute for Computational Biomedicine, Weill Cornell Medical College, New YorkNY, United States
| | - David Eliezer
- Department of Biochemistry, Weill Cornell Medical College, New YorkNY, United States
| | - Jeremy S Dittman
- Department of Biochemistry, Weill Cornell Medical College, New YorkNY, United States
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73
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Gordon DE, Chia J, Jayawardena K, Antrobus R, Bard F, Peden AA. VAMP3/Syb and YKT6 are required for the fusion of constitutive secretory carriers with the plasma membrane. PLoS Genet 2017; 13:e1006698. [PMID: 28403141 PMCID: PMC5406017 DOI: 10.1371/journal.pgen.1006698] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Revised: 04/26/2017] [Accepted: 03/15/2017] [Indexed: 11/19/2022] Open
Abstract
The cellular machinery required for the fusion of constitutive secretory vesicles with the plasma membrane in metazoans remains poorly defined. To address this problem we have developed a powerful, quantitative assay for measuring secretion and used it in combination with combinatorial gene depletion studies in Drosophila cells. This has allowed us to identify at least three SNARE complexes mediating Golgi to PM transport (STX1, SNAP24/29 and Syb; STX1, SNAP24/29 and YKT6; STX4, SNAP24 and Syb). RNAi mediated depletion of YKT6 and VAMP3 in mammalian cells also blocks constitutive secretion suggesting that YKT6 has an evolutionarily conserved role in this process. The unexpected role of YKT6 in plasma membrane fusion may in part explain why RNAi and gene disruption studies have failed to produce the expected phenotypes in higher eukaryotes.
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Affiliation(s)
- David E. Gordon
- University of California San Francisco, Department of Cellular and Molecular Pharmacology, San Francisco, CA, United States of America
| | - Joanne Chia
- Institute of Molecular and Cell Biology, 61 Biopolis Drive, Proteos, Singapore
| | - Kamburpola Jayawardena
- Cambridge Institute for Medical Research, University of Cambridge, Hills Road, Cambridge, United Kingdom
| | - Robin Antrobus
- Cambridge Institute for Medical Research, University of Cambridge, Hills Road, Cambridge, United Kingdom
| | - Frederic Bard
- Institute of Molecular and Cell Biology, 61 Biopolis Drive, Proteos, Singapore
| | - Andrew A. Peden
- Department of Biomedical Science & Centre for Membrane Interactions and Dynamics (CMIAD), The University of Sheffield, Western Bank, Sheffield, United Kingdom
- * E-mail:
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74
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Venkatesh D, Boehm C, Barlow LD, Nankissoor NN, O'Reilly A, Kelly S, Dacks JB, Field MC. Evolution of the endomembrane systems of trypanosomatids - conservation and specialisation. J Cell Sci 2017; 130:1421-1434. [PMID: 28386020 PMCID: PMC5399786 DOI: 10.1242/jcs.197640] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Accepted: 02/09/2017] [Indexed: 12/20/2022] Open
Abstract
Parasite surfaces support multiple functions required for survival within their hosts, and maintenance and functionality of the surface depends on membrane trafficking. To understand the evolutionary history of trypanosomatid trafficking, where multiple lifestyles and mechanisms of host interactions are known, we examined protein families central to defining intracellular compartments and mediating transport, namely Rabs, SNAREs and RabGAPs, across all available Euglenozoa genomes. Bodonids possess a large trafficking repertoire, which is mainly retained by the Trypanosoma cruzi group, with extensive losses in other lineages, particularly African trypanosomes and phytomonads. There are no large-scale expansions or contractions from an inferred ancestor, excluding direct associations between parasitism or host range. However, we observe stepwise secondary losses within Rab and SNARE cohorts (but not RabGAPs). Major changes are associated with endosomal and late exocytic pathways, consistent with the diversity in surface proteomes between trypanosomatids and mechanisms of interaction with the host. Along with the conserved core family proteins, several lineage-specific members of the Rab (but not SNARE) family were found. Significantly, testing predictions of SNARE complex composition by proteomics confirms generalised retention of function across eukaryotes.
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Affiliation(s)
- Divya Venkatesh
- Wellcome Trust Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, UK.,Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PQ, UK
| | - Cordula Boehm
- Wellcome Trust Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, UK
| | - Lael D Barlow
- Department of Cell Biology, University of Alberta, Edmonton, Alberta T6G 2H7, Canada
| | - Nerissa N Nankissoor
- Department of Cell Biology, University of Alberta, Edmonton, Alberta T6G 2H7, Canada
| | - Amanda O'Reilly
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PQ, UK
| | - Steven Kelly
- Department of Plant Sciences, University of Oxford, Oxford OX1 6JP, UK
| | - Joel B Dacks
- Department of Cell Biology, University of Alberta, Edmonton, Alberta T6G 2H7, Canada
| | - Mark C Field
- Wellcome Trust Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, UK
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75
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Kaur H, Sparvoli D, Osakada H, Iwamoto M, Haraguchi T, Turkewitz AP. An endosomal syntaxin and the AP-3 complex are required for formation and maturation of candidate lysosome-related secretory organelles (mucocysts) in Tetrahymena thermophila. Mol Biol Cell 2017; 28:1551-1564. [PMID: 28381425 PMCID: PMC5449153 DOI: 10.1091/mbc.e17-01-0018] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Revised: 03/22/2017] [Accepted: 03/28/2017] [Indexed: 12/14/2022] Open
Abstract
Lysosome-related organelles (LROs) are secretory organelles formed by convergence between secretory and endosomal trafficking pathways. In Tetrahymena, secretory vesicles that resemble dense core granules are a new class of LROs whose synthesis depends on a conserved syntaxin required for heterotypic fusion and AP-3 for maturation. The ciliate Tetrahymena thermophila synthesizes large secretory vesicles called mucocysts. Mucocyst biosynthesis shares features with dense core granules (DCGs) in animal cells, including proteolytic processing of cargo proteins during maturation. However, other molecular features have suggested relatedness to lysosome-related organelles (LROs). LROs, which include diverse organelles in animals, are formed via convergence of secretory and endocytic trafficking. Here we analyzed Tetrahymena syntaxin 7-like 1 (Stx7l1p), a Qa-SNARE whose homologues in other lineages are linked with vacuoles/LROs. Stx7l1p is targeted to both immature and mature mucocysts and is essential in mucocyst formation. In STX7L1-knockout cells, the two major classes of mucocyst cargo proteins localize independently, accumulating in largely nonoverlapping vesicles. Thus initial formation of immature mucocysts involves heterotypic fusion, in which a subset of mucocyst proteins is delivered via an endolysosomal compartment. Further, we show that subsequent maturation requires AP-3, a complex widely implicated in LRO formation. Knockout of the µ-subunit gene does not impede delivery of any known mucocyst cargo but nonetheless arrests mucocyst maturation. Our data argue that secretory organelles in ciliates may represent a new class of LROs and reveal key roles of an endosomal syntaxin and AP-3 in the assembly of this complex compartment.
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Affiliation(s)
- Harsimran Kaur
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL 60637
| | - Daniela Sparvoli
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL 60637
| | - Hiroko Osakada
- Advanced ICT Research Institute, National Institute of Information and Communications Technology, Kobe 651-2492, Japan
| | - Masaaki Iwamoto
- Advanced ICT Research Institute, National Institute of Information and Communications Technology, Kobe 651-2492, Japan
| | - Tokuko Haraguchi
- Advanced ICT Research Institute, National Institute of Information and Communications Technology, Kobe 651-2492, Japan.,Graduate School of Frontier Biosciences, Osaka University, Suita 565-0871, Japan
| | - Aaron P Turkewitz
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL 60637
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76
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Han J, Pluhackova K, Böckmann RA. The Multifaceted Role of SNARE Proteins in Membrane Fusion. Front Physiol 2017; 8:5. [PMID: 28163686 PMCID: PMC5247469 DOI: 10.3389/fphys.2017.00005] [Citation(s) in RCA: 171] [Impact Index Per Article: 24.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2016] [Accepted: 01/04/2017] [Indexed: 12/28/2022] Open
Abstract
Membrane fusion is a key process in all living organisms that contributes to a variety of biological processes including viral infection, cell fertilization, as well as intracellular transport, and neurotransmitter release. In particular, the various membrane-enclosed compartments in eukaryotic cells need to exchange their contents and communicate across membranes. Efficient and controllable fusion of biological membranes is known to be driven by cooperative action of SNARE proteins, which constitute the central components of the eukaryotic fusion machinery responsible for fusion of synaptic vesicles with the plasma membrane. During exocytosis, vesicle-associated v-SNARE (synaptobrevin) and target cell-associated t-SNAREs (syntaxin and SNAP-25) assemble into a core trans-SNARE complex. This complex plays a versatile role at various stages of exocytosis ranging from the priming to fusion pore formation and expansion, finally resulting in the release or exchange of the vesicle content. This review summarizes current knowledge on the intricate molecular mechanisms underlying exocytosis triggered and catalyzed by SNARE proteins. Particular attention is given to the function of the peptidic SNARE membrane anchors and the role of SNARE-lipid interactions in fusion. Moreover, the regulatory mechanisms by synaptic auxiliary proteins in SNARE-driven membrane fusion are briefly outlined.
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Affiliation(s)
- Jing Han
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science CenterXi'an, China; Computational Biology, Department of Biology, Friedrich-Alexander Universität Erlangen-NürnbergErlangen, Germany
| | - Kristyna Pluhackova
- Computational Biology, Department of Biology, Friedrich-Alexander Universität Erlangen-Nürnberg Erlangen, Germany
| | - Rainer A Böckmann
- Computational Biology, Department of Biology, Friedrich-Alexander Universität Erlangen-Nürnberg Erlangen, Germany
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77
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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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78
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Abstract
The early/recycling endosomes of an eukaryotic cell perform diverse cellular functions. In addition, the endosomal system generates multiple organelles, including certain cell type-specific organelles called lysosome-related organelles (LROs). The biosynthesis of these organelles possibly occurs through a sequential maturation process in which the cargo-containing endosomal vesicular/tubular structures are fused with the maturing organelle. The molecular machinery that regulates the cargo delivery or the membrane fusion during LRO biogenesis is poorly understood. Here, we describe the known key molecules, such as SNAREs, that regulate both the biogenesis and secretion of multiple LROs. Moreover, we also describe other regulatory molecules, such as Rab GTPases and their effectors that modulate the SNARE activity for cargo delivery to one such LRO, the melanosome. Overall, this review will increase our current understanding of LRO biogenesis and function.
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Affiliation(s)
- Riddhi Atul Jani
- a Department of Microbiology and Cell Biology ; Indian Institute of Science ; Bangalore , India
| | - Sarmistha Mahanty
- a Department of Microbiology and Cell Biology ; Indian Institute of Science ; Bangalore , India
| | - Subba Rao Gangi Setty
- a Department of Microbiology and Cell Biology ; Indian Institute of Science ; Bangalore , India
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79
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Whole Genome Sequencing Identifies a Novel Factor Required for Secretory Granule Maturation in Tetrahymena thermophila. G3-GENES GENOMES GENETICS 2016; 6:2505-16. [PMID: 27317773 PMCID: PMC4978903 DOI: 10.1534/g3.116.028878] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Unbiased genetic approaches have a unique ability to identify novel genes associated with specific biological pathways. Thanks to next generation sequencing, forward genetic strategies can be expanded to a wider range of model organisms. The formation of secretory granules, called mucocysts, in the ciliate Tetrahymena thermophila relies, in part, on ancestral lysosomal sorting machinery, but is also likely to involve novel factors. In prior work, multiple strains with defects in mucocyst biogenesis were generated by nitrosoguanidine mutagenesis, and characterized using genetic and cell biological approaches, but the genetic lesions themselves were unknown. Here, we show that analyzing one such mutant by whole genome sequencing reveals a novel factor in mucocyst formation. Strain UC620 has both morphological and biochemical defects in mucocyst maturation-a process analogous to dense core granule maturation in animals. Illumina sequencing of a pool of UC620 F2 clones identified a missense mutation in a novel gene called MMA1 (Mucocyst maturation). The defects in UC620 were rescued by expression of a wild-type copy of MMA1, and disrupting MMA1 in an otherwise wild-type strain phenocopies UC620. The product of MMA1, characterized as a CFP-tagged copy, encodes a large soluble cytosolic protein. A small fraction of Mma1p-CFP is pelletable, which may reflect association with endosomes. The gene has no identifiable homologs except in other Tetrahymena species, and therefore represents an evolutionarily recent innovation that is required for granule maturation.
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80
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Direct targeting of membrane fusion by SNARE mimicry: Convergent evolution of Legionella effectors. Proc Natl Acad Sci U S A 2016; 113:8807-12. [PMID: 27436892 DOI: 10.1073/pnas.1608755113] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Legionella pneumophila, the Gram-negative pathogen causing Legionnaires' disease, infects host cells by hijacking endocytic pathways and forming a Legionella-containing vacuole (LCV) in which the bacteria replicate. To promote LCV expansion and prevent lysosomal targeting, effector proteins are translocated into the host cell where they alter membrane traffic. Here we show that three of these effectors [LegC2 (Legionella eukaryotic-like gene C2)/YlfB (yeast lethal factor B), LegC3, and LegC7/YlfA] functionally mimic glutamine (Q)-SNARE proteins. In infected cells, the three proteins selectively form complexes with the endosomal arginine (R)-SNARE vesicle-associated membrane protein 4 (VAMP4). When reconstituted in proteoliposomes, these proteins avidly fuse with liposomes containing VAMP4, resulting in a stable complex with properties resembling canonical SNARE complexes. Intriguingly, however, the LegC/SNARE hybrid complex cannot be disassembled by N-ethylmaleimide-sensitive factor. We conclude that LegCs use SNARE mimicry to divert VAMP4-containing vesicles for fusion with the LCV, thus promoting its expansion. In addition, the LegC/VAMP4 complex avoids the host's disassembly machinery, thus effectively trapping VAMP4 in an inactive state.
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81
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Wang Y, Li L, Hou C, Lai Y, Long J, Liu J, Zhong Q, Diao J. SNARE-mediated membrane fusion in autophagy. Semin Cell Dev Biol 2016; 60:97-104. [PMID: 27422330 DOI: 10.1016/j.semcdb.2016.07.009] [Citation(s) in RCA: 78] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Revised: 07/07/2016] [Accepted: 07/08/2016] [Indexed: 12/28/2022]
Abstract
Autophagy, a conserved self-eating process for the bulk degradation of cytoplasmic materials, involves double-membrane autophagosomes formed when an isolation membrane emerges and their direct fusion with lysosomes for degradation. For the early biogenesis of autophagosomes and their later degradation in lysosomes, membrane fusion is necessary, although different sets of genes and autophagy-related proteins involved in distinct fusion steps have been reported. To clarify the molecular mechanism of membrane fusion in autophagy, to not only expand current knowledge of autophagy, but also benefit human health, this review discusses key findings that elucidate the unique membrane dynamics of autophagy.
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Affiliation(s)
- Yongyao Wang
- Center for Mitochondrial Biology and Medicine, Ministry of Education Key Laboratory of Biomedical Information Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, China; Department of Cancer Biology, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
| | - Linsen Li
- Center for Autophagy Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; State Key Lab of Animal Nutrition, China Agricultural University, Beijing 100193, China
| | - Chen Hou
- Center for Mitochondrial Biology and Medicine, Ministry of Education Key Laboratory of Biomedical Information Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, China
| | - Ying Lai
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA 94305, USA
| | - Jiangang Long
- Center for Mitochondrial Biology and Medicine, Ministry of Education Key Laboratory of Biomedical Information Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, China.
| | - Jiankang Liu
- Center for Mitochondrial Biology and Medicine, Ministry of Education Key Laboratory of Biomedical Information Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, China
| | - Qing Zhong
- Center for Autophagy Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
| | - Jiajie Diao
- Department of Cancer Biology, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA.
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82
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Zick M, Wickner W. Improved reconstitution of yeast vacuole fusion with physiological SNARE concentrations reveals an asymmetric Rab(GTP) requirement. Mol Biol Cell 2016; 27:2590-7. [PMID: 27385334 PMCID: PMC4985260 DOI: 10.1091/mbc.e16-04-0230] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Accepted: 06/21/2016] [Indexed: 11/11/2022] Open
Abstract
In vitro reconstitution is a powerful approach to deciphering membrane fusion. However, current reconstitutions do not adequately mimic the physiological process. This study takes a big step toward overcoming those shortcomings, achieving fusion with SNARE densities comparable to the native membrane. In vitro reconstitution of homotypic yeast vacuole fusion from purified components enables detailed study of membrane fusion mechanisms. Current reconstitutions have yet to faithfully replicate the fusion process in at least three respects: 1) The density of SNARE proteins required for fusion in vitro is substantially higher than on the organelle. 2) Substantial lysis accompanies reconstituted fusion. 3) The Rab GTPase Ypt7 is essential in vivo but often dispensable in vitro. Here we report that changes in fatty acyl chain composition dramatically lower the density of SNAREs that are required for fusion. By providing more physiological lipids with a lower phase transition temperature, we achieved efficient fusion with SNARE concentrations as low as on the native organelle. Although fused proteoliposomes became unstable at elevated SNARE concentrations, releasing their content after fusion had occurred, reconstituted proteoliposomes with substantially reduced SNARE concentrations fused without concomitant lysis. The Rab GTPase Ypt7 is essential on both membranes for proteoliposome fusion to occur at these SNARE concentrations. Strikingly, it was only critical for Ypt7 to be GTP loaded on membranes bearing the R-SNARE Nyv1, whereas the bound nucleotide of Ypt7 was irrelevant on membranes bearing the Q-SNAREs Vam3 and Vti1.
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Affiliation(s)
- Michael Zick
- Department of Biochemistry, Geisel School of Medicine at Dartmouth, Hanover, NH 03755-3844
| | - William Wickner
- Department of Biochemistry, Geisel School of Medicine at Dartmouth, Hanover, NH 03755-3844
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83
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Schroeter S, Beckmann S, Schmitt HD. Coat/Tether Interactions-Exception or Rule? Front Cell Dev Biol 2016; 4:44. [PMID: 27243008 PMCID: PMC4868844 DOI: 10.3389/fcell.2016.00044] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Accepted: 04/25/2016] [Indexed: 12/02/2022] Open
Abstract
Coat complexes are important for cargo selection and vesicle formation. Recent evidence suggests that they may also be involved in vesicle targeting. Tethering factors, which form an initial bridge between vesicles and the target membrane, may bind to coat complexes. In this review, we ask whether these coat/tether interactions share some common mechanisms, or whether they are special adaptations to the needs of very specific transport steps. We compare recent findings in two multisubunit tethering complexes, the Dsl1 complex and the HOPS complex, and put them into context with the TRAPP I complex as a prominent example for coat/tether interactions. We explore where coat/tether interactions are found, compare their function and structure, and comment on a possible evolution from a common ancestor of coats and tethers.
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Affiliation(s)
- Saskia Schroeter
- Neurobiology, Max Planck Institute for Biophysical Chemistry Göttingen, Germany
| | - Sabrina Beckmann
- Neurobiology, Max Planck Institute for Biophysical Chemistry Göttingen, Germany
| | - Hans Dieter Schmitt
- Neurobiology, Max Planck Institute for Biophysical Chemistry Göttingen, Germany
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84
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Bhat SS, Friedmann KS, Knörck A, Hoxha C, Leidinger P, Backes C, Meese E, Keller A, Rettig J, Hoth M, Qu B, Schwarz EC. Syntaxin 8 is required for efficient lytic granule trafficking in cytotoxic T lymphocytes. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2016; 1863:1653-64. [PMID: 27094127 DOI: 10.1016/j.bbamcr.2016.04.014] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Revised: 03/23/2016] [Accepted: 04/14/2016] [Indexed: 12/21/2022]
Abstract
Cytotoxic T lymphocytes (CTL) eliminate pathogen-infected and cancerous cells mainly by polarized secretion of lytic granules (LG, containing cytotoxic molecules like perforin and granzymes) at the immunological synapse (IS). Members of the SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) family are involved in trafficking (generation, transport and fusion) of vesicles at the IS. Syntaxin 8 (Stx8) is expressed in LG and colocalizes with the T cell receptor (TCR) upon IS formation. Here, we report the significance of Stx8 for human CTL cytotoxicity. We found that Stx8 mostly localized in late, recycling endosomal and lysosomal compartments with little expression in early endosomal compartments. Down-regulation of Stx8 by siRNA resulted in reduced cytotoxicity. We found that following perforin release of the pre-existing pool upon target cell contact, Stx8 down-regulated CTL regenerate perforin pools less efficiently and thus release less perforin compared to control CTL. CD107a degranulation, real-time and end-point population cytotoxicity assays, and high resolution microscopy support our conclusion that Stx8 is required for proper and timely sorting and trafficking of cytotoxic molecules to functional LG through the endosomal pathway in human CTL.
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Affiliation(s)
- Shruthi S Bhat
- Biophysics, Center for Integrative Physiology and Molecular Medicine, School of Medicine, Saarland University, Building 48, 66421 Homburg, Germany.
| | - Kim S Friedmann
- Biophysics, Center for Integrative Physiology and Molecular Medicine, School of Medicine, Saarland University, Building 48, 66421 Homburg, Germany.
| | - Arne Knörck
- Biophysics, Center for Integrative Physiology and Molecular Medicine, School of Medicine, Saarland University, Building 48, 66421 Homburg, Germany.
| | - Cora Hoxha
- Biophysics, Center for Integrative Physiology and Molecular Medicine, School of Medicine, Saarland University, Building 48, 66421 Homburg, Germany.
| | - Petra Leidinger
- Human Genetics, School of Medicine, Saarland University, Building 60, 66421 Homburg, Germany.
| | - Christina Backes
- Center for Bioinformatics, Saarland University, Building E2.1, 66123 Saarbrücken, Germany.
| | - Eckart Meese
- Human Genetics, School of Medicine, Saarland University, Building 60, 66421 Homburg, Germany.
| | - Andreas Keller
- Center for Bioinformatics, Saarland University, Building E2.1, 66123 Saarbrücken, Germany.
| | - Jens Rettig
- Physiology, Center for Integrative Physiology and Molecular Medicine, School of Medicine, Saarland University, Building 48, 66421 Homburg, Germany.
| | - Markus Hoth
- Biophysics, Center for Integrative Physiology and Molecular Medicine, School of Medicine, Saarland University, Building 48, 66421 Homburg, Germany.
| | - Bin Qu
- Biophysics, Center for Integrative Physiology and Molecular Medicine, School of Medicine, Saarland University, Building 48, 66421 Homburg, Germany.
| | - Eva C Schwarz
- Biophysics, Center for Integrative Physiology and Molecular Medicine, School of Medicine, Saarland University, Building 48, 66421 Homburg, Germany.
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85
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Liebeskind BJ, Hillis DM, Zakon HH, Hofmann HA. Complex Homology and the Evolution of Nervous Systems. Trends Ecol Evol 2015; 31:127-135. [PMID: 26746806 DOI: 10.1016/j.tree.2015.12.005] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Revised: 12/01/2015] [Accepted: 12/02/2015] [Indexed: 02/07/2023]
Abstract
We examine the complex evolution of animal nervous systems and discuss the ramifications of this complexity for inferring the nature of early animals. Although reconstructing the origins of nervous systems remains a central challenge in biology, and the phenotypic complexity of early animals remains controversial, a compelling picture is emerging. We now know that the nervous system and other key animal innovations contain a large degree of homoplasy, at least on the molecular level. Conflicting hypotheses about early nervous system evolution are due primarily to differences in the interpretation of this homoplasy. We highlight the need for explicit discussion of assumptions and discuss the limitations of current approaches for inferring ancient phenotypic states.
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Affiliation(s)
- Benjamin J Liebeskind
- Center for Systems and Synthetic Biology, University of Texas, Austin, TX 78712, USA; Institute for Cellular and Molecular Biology, University of Texas, Austin, TX 78712, USA; Center for Computational Biology and Bioinformatics, University of Texas, Austin, TX 78712.
| | - David M Hillis
- Institute for Cellular and Molecular Biology, University of Texas, Austin, TX 78712, USA; Center for Computational Biology and Bioinformatics, University of Texas, Austin, TX 78712; Department of Integrative Biology, University of Texas, Austin, TX 78712, USA
| | - Harold H Zakon
- Institute for Cellular and Molecular Biology, University of Texas, Austin, TX 78712, USA; Center for Computational Biology and Bioinformatics, University of Texas, Austin, TX 78712; Department of Integrative Biology, University of Texas, Austin, TX 78712, USA; Department of Neuroscience, University of Texas, Austin, TX 78712, USA; Institute for Neuroscience, University of Texas, Austin, TX 78712, USA; Josephine Bay Paul Center for Comparative Molecular Biology and Evolution, Marine Biological Laboratory, Woods Hole, MA 02543, USA
| | - Hans A Hofmann
- Institute for Cellular and Molecular Biology, University of Texas, Austin, TX 78712, USA; Center for Computational Biology and Bioinformatics, University of Texas, Austin, TX 78712; Department of Integrative Biology, University of Texas, Austin, TX 78712, USA; Department of Neuroscience, University of Texas, Austin, TX 78712, USA; Institute for Neuroscience, University of Texas, Austin, TX 78712, USA
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86
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López-Berges MS, Pinar M, Abenza JF, Arst HN, Peñalva MA. TheAspergillus nidulanssyntaxin PepAPep12is regulated by two Sec1/Munc-18 proteins to mediate fusion events at early endosomes, late endosomes and vacuoles. Mol Microbiol 2015; 99:199-216. [DOI: 10.1111/mmi.13226] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/21/2015] [Indexed: 01/21/2023]
Affiliation(s)
- Manuel S. López-Berges
- Departamento de Biología Celular y Molecular; Centro de Investigaciones Biológicas CSIC; Ramiro de Maeztu 9 Madrid 28040 Spain
| | - Mario Pinar
- Departamento de Biología Celular y Molecular; Centro de Investigaciones Biológicas CSIC; Ramiro de Maeztu 9 Madrid 28040 Spain
| | - Juan F. Abenza
- Departamento de Biología Celular y Molecular; Centro de Investigaciones Biológicas CSIC; Ramiro de Maeztu 9 Madrid 28040 Spain
| | - Herbert N. Arst
- Departamento de Biología Celular y Molecular; Centro de Investigaciones Biológicas CSIC; Ramiro de Maeztu 9 Madrid 28040 Spain
- Section of Microbiology; Flowers Building; Imperial College; London SW7 2AZ UK
| | - Miguel A. Peñalva
- Departamento de Biología Celular y Molecular; Centro de Investigaciones Biológicas CSIC; Ramiro de Maeztu 9 Madrid 28040 Spain
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87
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de Wiljes OO, van Elburg RAJ, Biehl M, Keijzer FA. Modeling spontaneous activity across an excitable epithelium: Support for a coordination scenario of early neural evolution. Front Comput Neurosci 2015; 9:110. [PMID: 26441620 PMCID: PMC4569742 DOI: 10.3389/fncom.2015.00110] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Accepted: 08/24/2015] [Indexed: 11/24/2022] Open
Abstract
Internal coordination models hold that early nervous systems evolved in the first place to coordinate internal activity at a multicellular level, most notably the use of multicellular contractility as an effector for motility. A recent example of such a model, the skin brain thesis, suggests that excitable epithelia using chemical signaling are a potential candidate as a nervous system precursor. We developed a computational model and a measure for whole body coordination to investigate the coordinative properties of such excitable epithelia. Using this measure we show that excitable epithelia can spontaneously exhibit body-scale patterns of activation. Relevant factors determining the extent of patterning are the noise level for exocytosis, relative body dimensions, and body size. In smaller bodies whole-body coordination emerges from cellular excitability and bidirectional excitatory transmission alone. Our results show that basic internal coordination as proposed by the skin brain thesis could have arisen in this potential nervous system precursor, supporting that this configuration may have played a role as a proto-neural system and requires further investigation.
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Affiliation(s)
- Oltman O. de Wiljes
- Department of Theoretical Philosophy, Faculty of Philosophy, University of GroningenGroningen, Netherlands
- Faculty of Mathematics and Natural Sciences, Institute of Artificial Intelligence, University of GroningenGroningen, Netherlands
| | - Ronald A. J. van Elburg
- Faculty of Mathematics and Natural Sciences, Institute of Artificial Intelligence, University of GroningenGroningen, Netherlands
| | - Michael Biehl
- Faculty of Mathematics and Natural Sciences, Johann Bernoulli Institute for Mathematics and Computer Science, University of GroningenGroningen, Netherlands
| | - Fred A. Keijzer
- Department of Theoretical Philosophy, Faculty of Philosophy, University of GroningenGroningen, Netherlands
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88
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Tarte VN, Seok HY, Woo DH, Le DH, Tran HT, Baik JW, Kang IS, Lee SY, Chung T, Moon YH. Arabidopsis Qc-SNARE gene AtSFT12 is involved in salt and osmotic stress responses and Na(+) accumulation in vacuoles. PLANT CELL REPORTS 2015; 34:1127-38. [PMID: 25689889 DOI: 10.1007/s00299-015-1771-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2014] [Accepted: 02/10/2015] [Indexed: 05/23/2023]
Abstract
AtSFT12, an Arabidopsis Qc-SNARE protein, is localized to Golgi organelles and is involved in salt and osmotic stress responses via accumulation of Na (+) in vacuoles. To reduce the detrimental effects of environmental stresses, plants have evolved many defense mechanisms. Here, we identified an Arabidopsis Qc-SNARE gene, AtSFT12, involved in salt and osmotic stress responses using an activation-tagging method. Both activation-tagged plants and overexpressing transgenic plants (OXs) of the AtSFT12 gene were tolerant to high concentrations of NaCl, LiCl, and mannitol, whereas loss-of-function mutants were sensitive to NaCl, LiCl, and mannitol. AtSFT12 transcription increased under NaCl, ABA, cold, and mannitol stresses but not MV treatment. GFP-fusion AtSFT12 protein was juxtaposed with Golgi marker, implying that its function is associated with Golgi-mediated transport. Quantitative measurement of Na(+) using induced coupled plasma atomic emission spectroscopy revealed that AtSFT12 OXs accumulated significantly more Na(+) than WT plants. In addition, Na(+)-dependent fluorescence analysis of Sodium Green showed comparatively higher Na(+) accumulation in vacuoles of AtSFT12 OX cells than in those of WT plant cells after salt treatments. Taken together, our findings suggest that AtSTF12, a Golgi Qc-SNARE protein, plays an important role in salt and osmotic stress responses and functions in the salt stress response via sequestration of Na(+) in vacuoles.
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Affiliation(s)
- Vaishali N Tarte
- Department of Molecular Biology, Pusan National University, Busan, 609-735, Korea
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89
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Praschberger R, Balint B, Mencacci NE, Hersheson J, Rubio-Agusti I, Kullmann DM, Bettencourt C, Bhatia K, Houlden H. Expanding the Phenotype and Genetic Defects Associated with the GOSR2 Gene. Mov Disord Clin Pract 2015; 2:271-273. [PMID: 30363482 DOI: 10.1002/mdc3.12190] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Revised: 03/23/2015] [Accepted: 03/25/2015] [Indexed: 01/24/2023] Open
Abstract
Background The homozygous missense mutation c.430G>T (p.G144W) in the GOSR2 gene has been repeatedly shown to cause progressive myoclonus epilepsy/ataxia. Thus far, no other disease associated GOSR2 mutation has been reported. Methods From epilepsy, movement disorder and genetic clinics 43 patients suffering from progressive myoclonus epilepsy/ataxia were screened for defects in GOSR2, SCARB2 and CSTB. Results A 61-year-old female patient suffering from progressive myoclonus epilepsy was found to be compound heterozygous for the known c.430G>T and a novel c.491_493delAGA (p.K164del) GOSR2 mutation. This is so far the oldest GOSR2 patient and her disease course seems overall milder. Conclusions This finding further highlights the GOSR2 gene as a cause of progressive myoclonus epilepsy and expands the genotype for a potentially weaker disease allele.
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Affiliation(s)
- Roman Praschberger
- Department of Molecular Neuroscience UCL Institute of Neurology and The National Hospital for Neurology and Neurosurgery (NHNN) London United Kingdom.,Department of Clinical and Experimental Epilepsy UCL Institute of Neurology London United Kingdom
| | - Bettina Balint
- Sobell Department of Motor Neuroscience and Movement Disorders UCL Institute of Neurology London United Kingdom.,Department of Neurology University Hospital Heidelberg Heidelberg Germany
| | - Niccolo E Mencacci
- Department of Molecular Neuroscience UCL Institute of Neurology and The National Hospital for Neurology and Neurosurgery (NHNN) London United Kingdom
| | - Joshua Hersheson
- Department of Molecular Neuroscience UCL Institute of Neurology and The National Hospital for Neurology and Neurosurgery (NHNN) London United Kingdom
| | | | - Dimitri M Kullmann
- Department of Clinical and Experimental Epilepsy UCL Institute of Neurology London United Kingdom
| | - Conceição Bettencourt
- Department of Molecular Neuroscience UCL Institute of Neurology and The National Hospital for Neurology and Neurosurgery (NHNN) London United Kingdom
| | - Kailash Bhatia
- Sobell Department of Motor Neuroscience and Movement Disorders UCL Institute of Neurology London United Kingdom
| | - Henry Houlden
- Department of Molecular Neuroscience UCL Institute of Neurology and The National Hospital for Neurology and Neurosurgery (NHNN) London United Kingdom
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90
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Ovsepian SV, Vesselkin NP. Wiring prior to firing: the evolutionary rise of electrical and chemical modes of synaptic transmission. Rev Neurosci 2015; 25:821-32. [PMID: 25051277 DOI: 10.1515/revneuro-2014-0037] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Accepted: 06/16/2014] [Indexed: 01/08/2023]
Abstract
Paracrine signaling and coupling via intercellular conduits are widely utilized for cell-cell interactions from primitive eukaryotes to advanced metazoa. Here, we review the functional and molecular data suggestive of a phylogenic continuum between these primeval forms of communication with the chemical and electrical synaptic transmission of neurons. We discuss selective evidence for the essential role played by the shift of function in early cellular morphologies and protosynaptic scaffolds, with their co-optation for new functionality, which ultimately lead to the rise of the chemical synapse. It is proposed that, rather than representing a transitional element, mixed electrochemical synapses exemplify an exaptive effect. The nonadaptive model of the synaptic origin described herein supports the pluralistic hypothesis of evolutionary change.
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91
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Jean S, Cox S, Nassari S, Kiger AA. Starvation-induced MTMR13 and RAB21 activity regulates VAMP8 to promote autophagosome-lysosome fusion. EMBO Rep 2015; 16:297-311. [PMID: 25648148 DOI: 10.15252/embr.201439464] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Autophagy, the process for recycling cytoplasm in the lysosome, depends on membrane trafficking. We previously identified Drosophila Sbf as a Rab21 guanine nucleotide exchange factor (GEF) that acts with Rab21 in endosomal trafficking. Here, we show that Sbf/MTMR13 and Rab21 have conserved functions required for starvation-induced autophagy. Depletion of Sbf/MTMR13 or Rab21 blocked endolysosomal trafficking of VAMP8, a SNARE required for autophagosome-lysosome fusion. We show that starvation induces Sbf/MTMR13 GEF and RAB21 activity, as well as their induced binding to VAMP8 (or closest Drosophila homolog, Vamp7). MTMR13 is required for RAB21 activation, VAMP8 interaction and VAMP8 endolysosomal trafficking, defining a novel GEF-Rab-effector pathway. These results identify starvation-responsive endosomal regulators and trafficking that tunes membrane demands with changing autophagy status.
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Affiliation(s)
- Steve Jean
- Division of Biological Sciences, University of California, San Diego, La Jolla, CA, USA
| | - Sarah Cox
- Division of Biological Sciences, University of California, San Diego, La Jolla, CA, USA
| | - Sonya Nassari
- Division of Biological Sciences, University of California, San Diego, La Jolla, CA, USA
| | - Amy A Kiger
- Division of Biological Sciences, University of California, San Diego, La Jolla, CA, USA
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92
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King NP, Newton P, Schuelein R, Brown DL, Petru M, Zarsky V, Dolezal P, Luo L, Bugarcic A, Stanley AC, Murray RZ, Collins BM, Teasdale RD, Hartland EL, Stow JL. Soluble NSF attachment protein receptor molecular mimicry by a Legionella pneumophila Dot/Icm effector. Cell Microbiol 2015; 17:767-84. [PMID: 25488819 DOI: 10.1111/cmi.12405] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Revised: 11/10/2014] [Accepted: 12/02/2014] [Indexed: 01/17/2023]
Abstract
Upon infection, Legionella pneumophila uses the Dot/Icm type IV secretion system to translocate effector proteins from the Legionella-containing vacuole (LCV) into the host cell cytoplasm. The effectors target a wide array of host cellular processes that aid LCV biogenesis, including the manipulation of membrane trafficking. In this study, we used a hidden Markov model screen to identify two novel, non-eukaryotic soluble NSF attachment protein receptor (SNARE) homologs: the bacterial Legionella SNARE effector A (LseA) and viral SNARE homolog A proteins. We characterized LseA as a Dot/Icm effector of L. pneumophila, which has close homology to the Qc-SNARE subfamily. The lseA gene was present in multiple sequenced L. pneumophila strains including Corby and was well distributed among L. pneumophila clinical and environmental isolates. Employing a variety of biochemical, cell biological and microbiological techniques, we found that farnesylated LseA localized to membranes associated with the Golgi complex in mammalian cells and LseA interacted with a subset of Qa-, Qb- and R-SNAREs in host cells. Our results suggested that LseA acts as a SNARE protein and has the potential to regulate or mediate membrane fusion events in Golgi-associated pathways.
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Affiliation(s)
- Nathan P King
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld., Australia
| | - Patrice Newton
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Vic., Australia
| | - Ralf Schuelein
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Vic., Australia
| | - Darren L Brown
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld., Australia
| | - Marketa Petru
- Department of Parasitology, Charles University in Prague, Czech Republic
| | - Vojtech Zarsky
- Department of Parasitology, Charles University in Prague, Czech Republic
| | - Pavel Dolezal
- Department of Parasitology, Charles University in Prague, Czech Republic
| | - Lin Luo
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld., Australia
| | - Andrea Bugarcic
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld., Australia
| | - Amanda C Stanley
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld., Australia
| | - Rachael Z Murray
- Tissue Repair and Regeneration Program, Institute of Health and Biomedical Innovation, School of Biomedical Sciences, Faculty of Health, Queensland University of Technology, Brisbane, Qld., Australia
| | - Brett M Collins
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld., Australia
| | - Rohan D Teasdale
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld., Australia
| | - Elizabeth L Hartland
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Vic., Australia
| | - Jennifer L Stow
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld., Australia
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93
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Ito Y, Uemura T, Nakano A. Formation and maintenance of the Golgi apparatus in plant cells. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2014; 310:221-87. [PMID: 24725428 DOI: 10.1016/b978-0-12-800180-6.00006-2] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The Golgi apparatus plays essential roles in intracellular trafficking, protein and lipid modification, and polysaccharide synthesis in eukaryotic cells. It is well known for its unique stacked structure, which is conserved among most eukaryotes. However, the mechanisms of biogenesis and maintenance of the structure, which are deeply related to ER-Golgi and intra-Golgi transport systems, have long been mysterious. Now having extremely powerful microscopic technologies developed for live-cell imaging, the plant Golgi apparatus provides an ideal system to resolve the question. The plant Golgi apparatus has unique features that are not conserved in other kingdoms, which will also give new insights into the Golgi functions in plant life. In this review, we will summarize the features of the plant Golgi apparatus and transport mechanisms around it, with a focus on recent advances in Golgi biogenesis by live imaging of plants cells.
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Affiliation(s)
- Yoko Ito
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Tomohiro Uemura
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Akihiko Nakano
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Bunkyo-ku, Tokyo, Japan; Live Cell Molecular Imaging Research Team, RIKEN Center for Advanced Photonics, Wako, Saitama, Japan.
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94
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Increased gene copy number of VAMP7 disrupts human male urogenital development through altered estrogen action. Nat Med 2014; 20:715-24. [PMID: 24880616 PMCID: PMC4283218 DOI: 10.1038/nm.3580] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2014] [Accepted: 04/23/2014] [Indexed: 02/07/2023]
Abstract
Vesicle transport is intimately connected with key nuclear functions and transcriptional regulation. Here, children born with congenital genitourinary tract masculinization disorders were analyzed by array-Comparative Genomic Hybridization, which revealed the presence of de novo copy number gains on Xq28 encompassing the VAMP7 gene encoding a vesicle-trafficking protein. Humanized VAMP7 BAC transgenic mice displayed cryptorchidism, urethral defects, and hypospadias. Mutant mice exhibited reduced penile length, focal spermatogenic anomalies, diminished sperm motility, and subfertility. VAMP7 colocalized with estrogen receptor alpha (ESR1) in the presence of ligand. Elevated levels of VAMP7 markedly intensified ESR1 transcriptional activity by increasing ESR1 protein cellular content upon ligand stimulation and up-regulated the expression of estrogen-responsive genes including ATF3, CYR61, and CTGF, all of which are implicated in human hypospadias. Hence, increased gene dosage of the SNARE protein, VAMP7, enhances estrogen receptor action in male genitourinary tissues, affects the virilization of the reproductive tract, and results in genitourinary birth defects in humans.
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95
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Simon M, Plattner H. Unicellular Eukaryotes as Models in Cell and Molecular Biology. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2014; 309:141-98. [DOI: 10.1016/b978-0-12-800255-1.00003-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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Murungi E, Barlow LD, Venkatesh D, Adung'a VO, Dacks JB, Field MC, Christoffels A. A comparative analysis of trypanosomatid SNARE proteins. Parasitol Int 2013; 63:341-8. [PMID: 24269876 PMCID: PMC3979113 DOI: 10.1016/j.parint.2013.11.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2013] [Revised: 11/07/2013] [Accepted: 11/10/2013] [Indexed: 12/03/2022]
Abstract
The Kinetoplastida are flagellated protozoa evolutionary distant and divergent from yeast and humans. Kinetoplastida include trypanosomatids, and a number of important pathogens. Trypanosoma brucei, Trypanosoma cruzi and Leishmania spp. inflict significant morbidity and mortality on humans and livestock as the etiological agents of human African trypanosomiasis, Chagas' disease and leishmaniasis respectively. For all of these organisms, intracellular trafficking is vital for maintenance of the host–pathogen interface, modulation/evasion of host immune system responses and nutrient uptake. Soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) are critical components of the intracellular trafficking machinery in eukaryotes, mediating membrane fusion and contributing to organelle specificity. We asked how the SNARE complement evolved across the trypanosomatids. An in silico search of the predicted proteomes of T. b. brucei and T. cruzi was used to identify candidate SNARE sequences. Phylogenetic analysis, including comparisons with yeast and human SNAREs, allowed assignment of trypanosomatid SNAREs to the Q or R subclass, as well as identification of several SNAREs orthologous with those of opisthokonts. Only limited variation in number and identity of SNAREs was found, with Leishmania major having 27 and T. brucei 26, suggesting a stable SNARE complement post-speciation. Expression analysis of T. brucei SNAREs revealed significant differential expression between mammalian and insect infective forms, especially within R and Qb-SNARE subclasses, suggesting possible roles in adaptation to different environments. For trypanosome SNAREs with clear orthologs in opisthokonts, the subcellular localization of TbVAMP7C is endosomal while both TbSyn5 and TbSyn16B are at the Golgi complex, which suggests conservation of localization and possibly also function. Despite highly distinct life styles, the complement of trypanosomatid SNAREs is quite stable between the three pathogenic lineages, suggesting establishment in the last common ancestor of trypanosomes and Leishmania. Developmental changes to SNARE mRNA levels between blood steam and procyclic life stages suggest that trypanosomes modulate SNARE functions via expression. Finally, the locations of some conserved SNAREs have been retained across the eukaryotic lineage. SNARE proteins are essential components of intracellular transport. These proteins exhibit considerable conservation across pathogenic trypanosomes. Some trypanosome SNARE families are expanded or lost. Developmental changes in trypanosome SNARE expression are apparent. Orthologous SNAREs demonstrate conserved locations and hence function.
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Affiliation(s)
- Edwin Murungi
- South African National Bioinformatics Institute, University of the Western Cape, Private Bag X17, Bellville 7535, Cape Town, South Africa
| | - Lael D Barlow
- Department of Cell Biology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta T6G 2H7, Canada
| | - Divya Venkatesh
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, UK
| | - Vincent O Adung'a
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, UK
| | - Joel B Dacks
- Department of Cell Biology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta T6G 2H7, Canada.
| | - Mark C Field
- Division of Biological Chemistry and Drug Discovery, University of Dundee, Dundee, Scotland DD1 5EH, UK.
| | - Alan Christoffels
- South African National Bioinformatics Institute, University of the Western Cape, Private Bag X17, Bellville 7535, Cape Town, South Africa.
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97
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Dunlap WC, Starcevic A, Baranasic D, Diminic J, Zucko J, Gacesa R, van Oppen MJH, Hranueli D, Cullum J, Long PF. KEGG orthology-based annotation of the predicted proteome of Acropora digitifera: ZoophyteBase - an open access and searchable database of a coral genome. BMC Genomics 2013; 14:509. [PMID: 23889801 PMCID: PMC3750612 DOI: 10.1186/1471-2164-14-509] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2013] [Accepted: 07/15/2013] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Contemporary coral reef research has firmly established that a genomic approach is urgently needed to better understand the effects of anthropogenic environmental stress and global climate change on coral holobiont interactions. Here we present KEGG orthology-based annotation of the complete genome sequence of the scleractinian coral Acropora digitifera and provide the first comprehensive view of the genome of a reef-building coral by applying advanced bioinformatics. DESCRIPTION Sequences from the KEGG database of protein function were used to construct hidden Markov models. These models were used to search the predicted proteome of A. digitifera to establish complete genomic annotation. The annotated dataset is published in ZoophyteBase, an open access format with different options for searching the data. A particularly useful feature is the ability to use a Google-like search engine that links query words to protein attributes. We present features of the annotation that underpin the molecular structure of key processes of coral physiology that include (1) regulatory proteins of symbiosis, (2) planula and early developmental proteins, (3) neural messengers, receptors and sensory proteins, (4) calcification and Ca2+-signalling proteins, (5) plant-derived proteins, (6) proteins of nitrogen metabolism, (7) DNA repair proteins, (8) stress response proteins, (9) antioxidant and redox-protective proteins, (10) proteins of cellular apoptosis, (11) microbial symbioses and pathogenicity proteins, (12) proteins of viral pathogenicity, (13) toxins and venom, (14) proteins of the chemical defensome and (15) coral epigenetics. CONCLUSIONS We advocate that providing annotation in an open-access searchable database available to the public domain will give an unprecedented foundation to interrogate the fundamental molecular structure and interactions of coral symbiosis and allow critical questions to be addressed at the genomic level based on combined aspects of evolutionary, developmental, metabolic, and environmental perspectives.
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Affiliation(s)
- Walter C Dunlap
- Centre for Marine Microbiology and Genetics, Australian Institute of Marine Science, PMB No. 3 Townsville MC, Townsville 4810, Queensland, Australia
- Institute of Pharmaceutical Science, King’s College London, Franklin-Wilkins Building, 150 Stamford Street, London SE1 9NH, United Kingdom
| | - Antonio Starcevic
- Section for Bioinformatics, Department of Biochemical Engineering, Faculty of Food Technology and Biotechnology, University of Zagreb, Pierottijeva 6, 10000 Zagreb, Croatia
| | - Damir Baranasic
- Section for Bioinformatics, Department of Biochemical Engineering, Faculty of Food Technology and Biotechnology, University of Zagreb, Pierottijeva 6, 10000 Zagreb, Croatia
| | - Janko Diminic
- Section for Bioinformatics, Department of Biochemical Engineering, Faculty of Food Technology and Biotechnology, University of Zagreb, Pierottijeva 6, 10000 Zagreb, Croatia
| | - Jurica Zucko
- Section for Bioinformatics, Department of Biochemical Engineering, Faculty of Food Technology and Biotechnology, University of Zagreb, Pierottijeva 6, 10000 Zagreb, Croatia
| | - Ranko Gacesa
- Section for Bioinformatics, Department of Biochemical Engineering, Faculty of Food Technology and Biotechnology, University of Zagreb, Pierottijeva 6, 10000 Zagreb, Croatia
| | - Madeleine JH van Oppen
- Centre for Marine Microbiology and Genetics, Australian Institute of Marine Science, PMB No. 3 Townsville MC, Townsville 4810, Queensland, Australia
| | - Daslav Hranueli
- Section for Bioinformatics, Department of Biochemical Engineering, Faculty of Food Technology and Biotechnology, University of Zagreb, Pierottijeva 6, 10000 Zagreb, Croatia
| | - John Cullum
- Department of Genetics, University of Kaiserslautern, Postfach 3049, 67653 Kaiserslautern, Germany
| | - Paul F Long
- Institute of Pharmaceutical Science, King’s College London, Franklin-Wilkins Building, 150 Stamford Street, London SE1 9NH, United Kingdom
- Department of Chemistry King’s College London, Franklin-Wilkins Building, 150 Stamford Street, London SE1 9NH, United Kingdom
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98
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Arasaki K, Takagi D, Furuno A, Sohda M, Misumi Y, Wakana Y, Inoue H, Tagaya M. A new role for RINT-1 in SNARE complex assembly at the trans-Golgi network in coordination with the COG complex. Mol Biol Cell 2013; 24:2907-17. [PMID: 23885118 PMCID: PMC3771952 DOI: 10.1091/mbc.e13-01-0014] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Yeast Tip20, a subunit of the Dsl1 complex, is implicated in Golgi-to–endoplasmic reticulum retrograde transport. Differing from Tip20, its mammalian counterpart, RINT-1, is required for endosome-to–trans-Golgi network transport. RINT-1 in coordination with the COG complex regulates SNARE complex assembly at the trans-Golgi network. Docking and fusion of transport vesicles/carriers with the target membrane involve a tethering factor–mediated initial contact followed by soluble N-ethylmaleimide–sensitive factor attachment protein receptor (SNARE)–catalyzed membrane fusion. The multisubunit tethering CATCHR family complexes (Dsl1, COG, exocyst, and GARP complexes) share very low sequence homology among subunits despite likely evolving from a common ancestor and participate in fundamentally different membrane trafficking pathways. Yeast Tip20, as a subunit of the Dsl1 complex, has been implicated in retrograde transport from the Golgi apparatus to the endoplasmic reticulum. Our previous study showed that RINT-1, the mammalian counterpart of yeast Tip20, mediates the association of ZW10 (mammalian Dsl1) with endoplasmic reticulum–localized SNARE proteins. In the present study, we show that RINT-1 is also required for endosome-to–trans-Golgi network trafficking. RINT-1 uncomplexed with ZW10 interacts with the COG complex, another member of the CATCHR family complex, and regulates SNARE complex assembly at the trans-Golgi network. This additional role for RINT-1 may in part reflect adaptation to the demand for more diverse transport routes from endosomes to the trans-Golgi network in mammals compared with those in a unicellular organism, yeast. The present findings highlight a new role of RINT-1 in coordination with the COG complex.
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Affiliation(s)
- Kohei Arasaki
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0392, Japan Division of Oral Biochemistry, Niigata University Graduate School of Medical and Dental Sciences, 2-5274 Gakkocho-dori, Chuo-ku, Niigata 951-8514, Japan Department of Cell Biology, Fukuoka University School of Medicine, Jonan-ku, Fukuoka 814-0180, Japan
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Abstract
The secretory pathway is responsible for the synthesis, folding, and delivery of a diverse array of cellular proteins. Secretory protein synthesis begins in the endoplasmic reticulum (ER), which is charged with the tasks of correctly integrating nascent proteins and ensuring correct post-translational modification and folding. Once ready for forward traffic, proteins are captured into ER-derived transport vesicles that form through the action of the COPII coat. COPII-coated vesicles are delivered to the early Golgi via distinct tethering and fusion machineries. Escaped ER residents and other cycling transport machinery components are returned to the ER via COPI-coated vesicles, which undergo similar tethering and fusion reactions. Ultimately, organelle structure, function, and cell homeostasis are maintained by modulating protein and lipid flux through the early secretory pathway. In the last decade, structural and mechanistic studies have added greatly to the strong foundation of yeast genetics on which this field was built. Here we discuss the key players that mediate secretory protein biogenesis and trafficking, highlighting recent advances that have deepened our understanding of the complexity of this conserved and essential process.
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100
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Genome-wide identification, phylogeny and expression profile of vesicle fusion components in Verticillium dahliae. PLoS One 2013; 8:e68681. [PMID: 23874720 PMCID: PMC3714278 DOI: 10.1371/journal.pone.0068681] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2013] [Accepted: 06/02/2013] [Indexed: 12/31/2022] Open
Abstract
Vesicular trafficking plays a crucial role in protein localization and movement, signal transduction, and multiple developmental processes in eukaryotic cells. Vesicle fusion is the final and key step in vesicle-mediated trafficking and mainly relies on SNAREs (soluble N-ethylmaleimide-sensitive factor attachment protein receptors), the regulators including SM (Sec1/Munc18) family proteins, Rab GTPases and exocyst subunits. Verticillium dahliae is a widespread soil fungus that causes disruptive vascular diseases on a wide range of plants. To date, no genes involved in vesicular fusion process have been identified and characterized in V. dahliae. The recent publication of the draft genome sequence of V. dahliae allowed us to conduct a genome-wide identification, phylogeny and expression profile of genes encoding vesicular fusion components. Using compared genomics and phylogenetic methods, we identified 44 genes encoding vesicle fusion components in the V. dahliae genome. According to the structural features of their encoded proteins, the 44 V. dahliae genes were classified into 22 SNAREs (6 Qa-, 4 Qb-, 6 Qc-, 1 Qbc- and 5 R-types), 4 SM family proteins, 10 Rab GTPases and 8 exocyst proteins. Based on phylogeny and motif constitution analysis, orthologs of vesicle fusion component in filamentous fungi were generally clustered together into the same subclasses with well-supported bootstrap values. Analysis of the expression profiles of these genes indicated that many of them are significantly differentially expressed during vegetative growth and microsclerotia formation in V. dahliae. The analysis show that many components of vesicle fusion are well conserved in filamentous fungi and indicate that vesicle fusion plays a critical role in microsclerotia formation of smoke tree wilt fungus V. dahliae. The genome-wide identification and expression analysis of components involved in vesicle fusion should facilitate research in this gene family and give new insights toward elucidating their functions in growth, development and pathogenesis of V. dahliae.
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