Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
8.3
5.5
Journals
Biomolecules
Special Issues
Molecular Mechanism Investigations into Membrane Fusion
share announcement

Molecular Mechanism Investigations into Membrane Fusion

A special issue of Biomolecules (ISSN 2218-273X). This special issue belongs to the section "Cellular Biochemistry".

Deadline for manuscript submissions: 15 September 2024 | Viewed by 7586

Special Issue Editor

Dr. James McNew

E-Mail Website
Guest Editor
Department of Biosciences, Rice University, Houston, TX, USA
Interests: phospholipids; biochemistry

Special Issue Information

Dear Colleagues,

Membrane fusion accomplishes the regulated and specific merger of phospholipid membranes with subsequent aqueous content mixing necessary for the delivery and transport of protein and lipid cargoes. This process occurs at all membrane interfaces within the eukaryotic cell and is catalyzed by specific classes of membrane fusion proteins or fusogens.

This Special Issue of Biomolecules on the “Molecular Mechanism Investigations into Membrane Fusion” will focus on recent advances regarding the mechanistic basis of membrane fusion by all classes of fusion proteins. Both research and review articles are welcomed that discuss vesicular fusion within the secretory pathway by SNARE proteins, organelles biogenesis and maintenance by atlastins and mitofusins, viral infection by enveloped viral fusion proteins as a well as reoviral encoded FAST proteins, and finally, cell–cell fusion and syncytial formation driven by the fusexin family and related members.

Dr. James McNew
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Biomolecules is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2700 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Published Papers (5 papers)

Download All Papers
Order results
Result details
Show export options expand_more Show export options expand_less
Select all
Export citation of selected articles as:

Research

Jump to: Review

15 pages, 4458 KiB  
Article
Phosphorylation of Syntaxin 4 by the Insulin Receptor Drives Exocytic SNARE Complex Formation to Deliver GLUT4 to the Cell Surface
by Dimitrios Kioumourtzoglou, Hannah L. Black, Mohammed Al Tobi, Rachel Livingstone, John R. Petrie, James G. Boyle, Gwyn W. Gould and Nia J. Bryant
Biomolecules 2023, 13(12), 1738; https://doi.org/10.3390/biom13121738 - 02 Dec 2023
Viewed by 1052
Abstract
A major consequence of insulin binding its receptor on fat and muscle cells is the stimulation of glucose transport into these tissues. This is achieved through an increase in the exocytic trafficking rate of the facilitative glucose transporter GLUT4 from intracellular stores to [...] Read more.
A major consequence of insulin binding its receptor on fat and muscle cells is the stimulation of glucose transport into these tissues. This is achieved through an increase in the exocytic trafficking rate of the facilitative glucose transporter GLUT4 from intracellular stores to the cell surface. Delivery of GLUT4 to the cell surface requires the formation of functional SNARE complexes containing Syntaxin 4, SNAP23, and VAMP2. Insulin stimulates the formation of these complexes and concomitantly causes phosphorylation of Syntaxin 4. Here, we use a combination of biochemistry and cell biological approaches to provide a mechanistic link between these observations. We present data to support the hypothesis that Tyr-115 and Tyr-251 of Syntaxin 4 are direct substrates of activated insulin receptors, and that these residues modulate the protein’s conformation and thus regulate the rate at which Syntaxin 4 forms SNARE complexes that deliver GLUT4 to the cell surface. This report provides molecular details on how the cell regulates SNARE-mediated membrane traffic in response to an external stimulus. Full article
(This article belongs to the Special Issue Molecular Mechanism Investigations into Membrane Fusion)
►▼ Show Figures

Figure 1

14 pages, 2613 KiB  
Article
Regulation of Syntaxin3B-Mediated Membrane Fusion by T14, Munc18, and Complexin
by Rajkishor Nishad, Miguel Betancourt-Solis, Himani Dey, Ruth Heidelberger and James A. McNew
Biomolecules 2023, 13(10), 1463; https://doi.org/10.3390/biom13101463 - 28 Sep 2023
Viewed by 1010
Abstract
Retinal neurons that form ribbon-style synapses operate over a wide dynamic range, continuously relaying visual information to their downstream targets. The remarkable signaling abilities of these neurons are supported by specialized presynaptic machinery, one component of which is syntaxin3B. Syntaxin3B is an essential [...] Read more.
Retinal neurons that form ribbon-style synapses operate over a wide dynamic range, continuously relaying visual information to their downstream targets. The remarkable signaling abilities of these neurons are supported by specialized presynaptic machinery, one component of which is syntaxin3B. Syntaxin3B is an essential t-SNARE protein of photoreceptors and bipolar cells that is required for neurotransmitter release. It has a light-regulated phosphorylation site in its N-terminal domain at T14 that has been proposed to modulate membrane fusion. However, a direct test of the latter has been lacking. Using a well-controlled in vitro fusion assay, we found that a phosphomimetic T14 syntaxin3B mutation leads to a small but significant enhancement of SNARE-mediated membrane fusion following the formation of the t-SNARE complex. While the addition of Munc18a had only a minimal effect on membrane fusion mediated by SNARE complexes containing wild-type syntaxin3B, a more significant enhancement was observed in the presence of Munc18a when the SNARE complexes contained a syntaxin3B T14 phosphomimetic mutant. Finally, we showed that the retinal-specific complexins (Cpx III and Cpx IV) inhibited membrane fusion mediated by syntaxin3B-containing SNARE complexes in a dose-dependent manner. Collectively, our results establish that membrane fusion mediated by syntaxin3B-containing SNARE complexes is regulated by the T14 residue of syntaxin3B, Munc18a, and Cpxs III and IV. Full article
(This article belongs to the Special Issue Molecular Mechanism Investigations into Membrane Fusion)
►▼ Show Figures

Figure 1

15 pages, 1893 KiB  
Article
Role of Lipids and Divalent Cations in Membrane Fusion Mediated by the Heptad Repeat Domain 1 of Mitofusin
by Anaïs Vlieghe, Kristina Niort, Hugo Fumat, Jean-Michel Guigner, Mickaël M. Cohen and David Tareste
Biomolecules 2023, 13(9), 1341; https://doi.org/10.3390/biom13091341 - 02 Sep 2023
Viewed by 1406
Abstract
Mitochondria are highly dynamic organelles that constantly undergo fusion and fission events to maintain their shape, distribution and cellular function. Mitofusin 1 and 2 proteins are two dynamin-like GTPases involved in the fusion of outer mitochondrial membranes (OMM). Mitofusins are anchored to the [...] Read more.
Mitochondria are highly dynamic organelles that constantly undergo fusion and fission events to maintain their shape, distribution and cellular function. Mitofusin 1 and 2 proteins are two dynamin-like GTPases involved in the fusion of outer mitochondrial membranes (OMM). Mitofusins are anchored to the OMM through their transmembrane domain and possess two heptad repeat domains (HR1 and HR2) in addition to their N-terminal GTPase domain. The HR1 domain was found to induce fusion via its amphipathic helix, which interacts with the lipid bilayer structure. The lipid composition of mitochondrial membranes can also impact fusion. However, the precise mode of action of lipids in mitochondrial fusion is not fully understood. In this study, we examined the role of the mitochondrial lipids phosphatidylethanolamine (PE), cardiolipin (CL) and phosphatidic acid (PA) in membrane fusion induced by the HR1 domain, both in the presence and absence of divalent cations (Ca2+ or Mg2+). Our results showed that PE, as well as PA in the presence of Ca2+, effectively stimulated HR1-mediated fusion, while CL had a slight inhibitory effect. By considering the biophysical properties of these lipids in the absence or presence of divalent cations, we inferred that the interplay between divalent cations and specific cone-shaped lipids creates regions with packing defects in the membrane, which provides a favorable environment for the amphipathic helix of HR1 to bind to the membrane and initiate fusion. Full article
(This article belongs to the Special Issue Molecular Mechanism Investigations into Membrane Fusion)
►▼ Show Figures

Figure 1

20 pages, 7260 KiB  
Article
Cyclosporines Antagonize the Antiviral Activity of IFITMProteins by Redistributing Them toward the Golgi Apparatus
by David Prikryl, Mariana Marin, Tanay M. Desai, Yuhong Du, Haian Fu and Gregory B. Melikyan
Biomolecules 2023, 13(6), 937; https://doi.org/10.3390/biom13060937 - 03 Jun 2023
Cited by 1 | Viewed by 1727
Abstract
Interferon-induced transmembrane proteins (IFITMs) block the fusion of diverse enveloped viruses, likely through increasing the cell membrane’s rigidity. Previous studies have reported that the antiviral activity of the IFITM family member, IFITM3, is antagonized by cell pretreatment with rapamycin derivatives and cyclosporines A [...] Read more.
Interferon-induced transmembrane proteins (IFITMs) block the fusion of diverse enveloped viruses, likely through increasing the cell membrane’s rigidity. Previous studies have reported that the antiviral activity of the IFITM family member, IFITM3, is antagonized by cell pretreatment with rapamycin derivatives and cyclosporines A and H (CsA and CsH) that promote the degradation of IFITM3. Here, we show that CsA and CsH potently enhance virus fusion with IFITM1- and IFITM3-expressing cells by inducing their rapid relocalization from the plasma membrane and endosomes, respectively, towards the Golgi. This relocalization is not associated with a significant degradation of IFITMs. Although prolonged exposure to CsA induces IFITM3 degradation in cells expressing low endogenous levels of this protein, its levels remain largely unchanged in interferon-treated cells or cells ectopically expressing IFITM3. Importantly, the CsA-mediated redistribution of IFITMs to the Golgi occurs on a much shorter time scale than degradation and thus likely represents the primary mechanism of enhancement of virus entry. We further show that rapamycin also induces IFITM relocalization toward the Golgi, albeit less efficiently than cyclosporines. Our findings highlight the importance of regulation of IFITM trafficking for its antiviral activity and reveal a novel mechanism of the cyclosporine-mediated modulation of cell susceptibility to enveloped virus infection. Full article
(This article belongs to the Special Issue Molecular Mechanism Investigations into Membrane Fusion)
►▼ Show Figures

Figure 1

Review

Jump to: Research

32 pages, 4133 KiB  
Review
A Frame-by-Frame Glance at Membrane Fusion Mechanisms: From Viral Infections to Fertilization
by Farshad C. Azimi, Trevor T. Dean, Karine Minari, Luis G. M. Basso, Tyler D. R. Vance and Vitor Hugo B. Serrão
Biomolecules 2023, 13(7), 1130; https://doi.org/10.3390/biom13071130 - 14 Jul 2023
Cited by 2 | Viewed by 1931
Abstract
Viral entry and fertilization are distinct biological processes that share a common mechanism: membrane fusion. In viral entry, enveloped viruses attach to the host cell membrane, triggering a series of conformational changes in the viral fusion proteins. This results in the exposure of [...] Read more.
Viral entry and fertilization are distinct biological processes that share a common mechanism: membrane fusion. In viral entry, enveloped viruses attach to the host cell membrane, triggering a series of conformational changes in the viral fusion proteins. This results in the exposure of a hydrophobic fusion peptide, which inserts into the host membrane and brings the viral and host membranes into close proximity. Subsequent structural rearrangements in opposing membranes lead to their fusion. Similarly, membrane fusion occurs when gametes merge during the fertilization process, though the exact mechanism remains unclear. Structural biology has played a pivotal role in elucidating the molecular mechanisms underlying membrane fusion. High-resolution structures of the viral and fertilization fusion-related proteins have provided valuable insights into the conformational changes that occur during this process. Understanding these mechanisms at a molecular level is essential for the development of antiviral therapeutics and tools to influence fertility. In this review, we will highlight the biological importance of membrane fusion and how protein structures have helped visualize both common elements and subtle divergences in the mechanisms behind fusion; in addition, we will examine the new tools that recent advances in structural biology provide researchers interested in a frame-by-frame understanding of membrane fusion. Full article
(This article belongs to the Special Issue Molecular Mechanism Investigations into Membrane Fusion)
►▼ Show Figures

Figure 1

Show export options expand_more Show export options expand_less
Select all
Export citation of selected articles as:
 
Displaying articles 1-5
Back to TopTop