scholarly journals A non-zipper-like tetrameric coiled coil promotes membrane fusion

RSC Advances ◽  
2016 ◽  
Vol 6 (10) ◽  
pp. 7990-7998 ◽  
Author(s):  
Tingting Zheng ◽  
Monica Bulacu ◽  
Geert Daudey ◽  
Frank Versluis ◽  
Jens Voskuhl ◽  
...  
Keyword(s):  
Membrane Fusion ◽  
Coiled Coil

A parallel heterodimeric coiled coil can be mutated to an antiparallel tetrameric species by reversing the sequences of one of the peptides. This tetramer is capable of facilitating fast, efficient, membrane fusion of liposomes.

scholarly journals Coiled-coil formation of the membrane-fusion K/E peptides viewed by electron paramagnetic resonance

PLoS ONE ◽  
2018 ◽  
Vol 13 (1) ◽  
pp. e0191197 ◽  
Author(s):  
Pravin Kumar ◽  
Martin van Son ◽  
Tingting Zheng ◽  
Dayenne Valdink ◽  
Jan Raap ◽  
...  
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Membrane Fusion ◽  
Coiled Coil ◽  
Paramagnetic Resonance ◽  
Electron Paramagnetic

scholarly journals Coassembly of Mgm1 isoforms requires cardiolipin and mediates mitochondrial inner membrane fusion

2009 ◽  
Vol 186 (6) ◽  
pp. 793-803 ◽  
Author(s):  
Rachel M. DeVay ◽  
Lenin Dominguez-Ramirez ◽  
Laura L. Lackner ◽  
Suzanne Hoppins ◽  
Henning Stahlberg ◽  
...  
Keyword(s):  
Membrane Fusion ◽  
Coiled Coil ◽  
Intermembrane Space ◽  
Dependent Manner ◽  
Related Protein ◽  
Mitochondrial Membranes ◽  
Inner Membrane ◽  
Mitochondrial Inner Membrane ◽  
N Terminus ◽  
In Trans

Two dynamin-related protein (DRP) families are essential for fusion of the outer and inner mitochondrial membranes, Fzo1 (yeast)/Mfn1/Mfn2 (mammals) and Mgm1 (yeast)/Opa1 (mammals), respectively. Fzo1/Mfns possess two medial transmembrane domains, which place their critical GTPase and coiled-coil domains in the cytosol. In contrast, Mgm1/Opa1 are present in cells as long (l) isoforms that are anchored via the N terminus to the inner membrane, and short (s) isoforms were predicted to be soluble in the intermembrane space. We addressed the roles of Mgm1 isoforms and how DRPs function in membrane fusion. Our analysis indicates that in the absence of a membrane, l- and s-Mgm1 both exist as inactive GTPase monomers, but that together in trans they form a functional dimer in a cardiolipin-dependent manner that is the building block for higher-order assemblies.

Coiled coil driven membrane fusion between cyclodextrin vesicles and liposomes

Soft Matter ◽  
2014 ◽  
Vol 10 (48) ◽  
pp. 9746-9751 ◽  
Author(s):  
Frank Versluis ◽  
Jens Voskuhl ◽  
Jan Vos ◽  
Heiner Friedrich ◽  
Bart Jan Ravoo ◽  
...  
Keyword(s):  
Membrane Fusion ◽  
Coiled Coil

scholarly journals Nonhelical Leash and α-Helical Structures Determine the Potency of a Peptide Antagonist of Human T-Cell Leukemia Virus Entry

2008 ◽  
Vol 82 (10) ◽  
pp. 4965-4973 ◽  
Author(s):  
Antonis Mirsaliotis ◽  
Daniel Lamb ◽  
David W. Brighty
Keyword(s):  
Amino Acid ◽  
T Cell ◽  
Membrane Fusion ◽  
Fusion Proteins ◽  
Leukemia Virus ◽  
Coiled Coil ◽  
Cell Leukemia ◽  
Inhibitory Peptide ◽  
Human T Cell ◽  
T Cell Leukemia Virus

ABSTRACT Viral fusion proteins mediate the entry of enveloped viral particles into cells by inducing fusion of the viral and target cell membranes. Activated fusion proteins undergo a cascade of conformational transitions and ultimately resolve into a compact trimer of hairpins or six-helix bundle structure, which pulls the interacting membranes together to promote lipid mixing. Significantly, synthetic peptides based on a C-terminal region of the trimer of hairpins are potent inhibitors of membrane fusion and viral entry, and such peptides are typically extensively α-helical. In contrast, an atypical peptide inhibitor of human T-cell leukemia virus (HTLV) includes α-helical and nonhelical leash segments. We demonstrate that both the C helix and C-terminal leash are critical to the inhibitory activities of these peptides. Amino acid side chains in the leash and C helix extend into deep hydrophobic pockets at the membrane-proximal end of the HTLV type 1 (HTLV-1) coiled coil, and these contacts are necessary for potent antagonism of membrane fusion. In addition, a single amino acid substitution within the inhibitory peptide improves peptide interaction with the core coiled coil and yields a peptide with enhanced potency. We suggest that the deep pockets on the coiled coil are ideal targets for small-molecule inhibitors of HTLV-1 entry into cells. Moreover, the extended nature of the HTLV-1-inhibitory peptide suggests that such peptides may be intrinsically amenable to modifications designed to improve inhibitory activity. Finally, we propose that leash-like mimetic peptides may be of value as entry inhibitors for other clinically important viral infections.

Polymorphism, Heteroplasmy, Mitochondrial Fusion and Diabetes

2003 ◽  
Vol 23 (5-6) ◽  
pp. 313-337 ◽  
Author(s):  
Aya Sato ◽  
Hitoshi Endo ◽  
Kazuo Umetsu ◽  
Hideyuki Sone ◽  
Yoshiko Yanagisawa ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Mitochondrial Dna ◽  
Membrane Fusion ◽  
Coiled Coil ◽  
Reactive Oxygen ◽  
Mitochondrial Fusion ◽  
Vicious Circle ◽  
Oxygen Species ◽  
The Brain

Mitochondrial DNA (mtDNA) is highly susceptible to mutations that result in polymorphisms and diseases including diabetes. We analyzed heteroplasmy, polymorphisms related to diabetes, and complementation by fusogenic proteins. Cytoplast fusion and microinjection allow, defects in mutated mtDNA inside a heteroplasmic cell to be complemented by fusing two mitochondria via human fusogenic proteins. We characterized three hfzos as well as two OPA1s that prevent apoptosis. Two coiled coil domains and GTPase domains in these fusogenic proteins regulate membrane fusion. The hfzo genes were expressed mainly in the brain and in muscle that are postmitotic, but not in the pancreas. Under the in.uence of polymorphisms of mtDNA and nDNA, the vicious circle of reactive oxygen species and mutations in cell can be alleviated by mitochondrial fusion.

scholarly journals Suppressor Analysis of the Fusogenic Lambda Spanins

2017 ◽  
Vol 91 (14) ◽  
Author(s):  
Jesse Cahill ◽  
Manoj Rajaure ◽  
Ashley Holt ◽  
Russell Moreland ◽  
Chandler O'Leary ◽  
...  
Keyword(s):  
Genetic Analysis ◽  
Membrane Fusion ◽  
Cell Envelope ◽  
Coiled Coil ◽  
Class I ◽  
Intermediate Structure ◽  
Content Type ◽  
Outer Membranes ◽  
Fusion Systems ◽  
Suppressor Analysis

ABSTRACT The final step of lysis in phage λ infections of Escherichia coli is mediated by the spanins Rz and Rz1. These proteins form a complex that bridges the cell envelope and that has been proposed to cause fusion of the inner and outer membranes. Accordingly, mutations that block spanin function are found within coiled-coil domains and the proline-rich region, motifs essential in other fusion systems. To gain insight into spanin function, pseudorevertant alleles that restored plaque formation for lysis-defective mutants of Rz and Rz1 were selected. Most second-site suppressors clustered within a coiled-coil domain of Rz near the outer leaflet of the cytoplasmic membrane and were not allele specific. Suppressors largely encoded polar insertions within the hydrophobic core of the coiled-coil interface. Such suppressor changes resulted in decreased proteolytic stability of the Rz double mutants in vivo. Unlike the wild type, in which lysis occurs while the cells retain a rod shape, revertant alleles with second-site suppressor mutations supported lysis events that were preceded by spherical cell formation. This suggests that destabilization of the membrane-proximal coiled coil restores function for defective spanin alleles by increasing the conformational freedom of the complex at the cost of its normal, all-or-nothing functionality. IMPORTANCE Caudovirales encode cell envelope-spanning proteins called spanins, which are thought to fuse the inner and outer membranes during phage lysis. Recent genetic analysis identified the functional domains of the lambda spanins, which are similar to class I viral fusion proteins. While the pre- and postfusion structures of model fusion systems have been well characterized, the intermediate structure(s) formed during the fusion reaction remains elusive. Genetic analysis would be expected to identify functional connections between intermediates. Since most membrane fusion systems are not genetically tractable, only few such investigations have been reported. Here, we report a suppressor analysis of lambda spanin function. To our knowledge this is the first suppression analysis of a class I-like complex and also the first such analysis of a prokaryote membrane fusion system.

scholarly journals Targeted anion transporter delivery by coiled-coil driven membrane fusion

2016 ◽  
Vol 7 (3) ◽  
pp. 1768-1772 ◽  
Author(s):  
Nestor Lopez Mora ◽  
Azadeh Bahreman ◽  
Hennie Valkenier ◽  
Hongyu Li ◽  
Thomas H. Sharp ◽  
...  
Keyword(s):  
Membrane Fusion ◽  
Biomedical Research ◽  
Coiled Coil ◽  
Research Tool ◽  
Anion Transporters ◽  
Anion Transporter ◽  
Potential Use

Membrane fusion was used to deliver lipophilic synthetic anion transporters to membranes of GUVs and cells, bringing the potential use as a therapeutic or biomedical research tool closer.

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