• Membrane fusion proteins (not to be confused with chimeric or fusion proteins) are proteins that cause fusion of biological membranes. (wikipedia.org)
  • Fusion proteins can originate from genes encoded by infectious enveloped viruses, ancient retroviruses integrated into the host genome, or solely by the host genome. (wikipedia.org)
  • Post-transcriptional modifications made to the fusion proteins by the host, namely addition and modification of glycans and acetyl groups, can drastically affect fusogenicity (the ability to fuse). (wikipedia.org)
  • Vesicle fusion events involved in neurotransmitter trafficking also relies on the catalytic activity of fusion proteins. (wikipedia.org)
  • The SNARE family include bona fide eukaryotic fusion proteins. (wikipedia.org)
  • They are domesticated viral class I fusion proteins. (wikipedia.org)
  • Enveloped viruses readily overcome the thermodynamic barrier of merging two plasma membranes by storing kinetic energy in fusion (F) proteins. (wikipedia.org)
  • F proteins can be independently expressed on host cell surfaces which can either (1) drive the infected cell to fuse with neighboring cells, forming a syncytium, or (2) be incorporated into a budding virion from the infected cell which leads to the full emancipation of plasma membrane from the host cell. (wikipedia.org)
  • Some F components solely drive fusion while a subset of F proteins can interact with host factors. (wikipedia.org)
  • There are four groups of fusion proteins categorized by their structure and mechanism of fusion. (wikipedia.org)
  • Class I fusion proteins resemble influenzavirus hemagglutinin in their structure. (wikipedia.org)
  • Class III fusion proteins are distinct from I and II. (wikipedia.org)
  • Class IV fusion proteins, better known as fusion-associated small transmembrane proteins (FAST), are the smallest type of fusion protein. (wikipedia.org)
  • They are the only known membrane fusion proteins found in non-enveloped viruses. (wikipedia.org)
  • Interbilayer forces in membrane fusion Viral membrane fusion proteins Classification of viral fusion proteins in TCDB database Klapper R, Stute C, Schomaker O, Strasser T, Janning W, Renkawitz-Pohl R, Holz A (January 2002). (wikipedia.org)
  • In particular, polymer-encapsulated nanodiscs enable the study of membrane proteins at high resolution while retaining protein-protein and protein-lip. (researchgate.net)
  • This review summarizes key aspects of tetraspanin proteins, with a focus on the functional relevance and structural features of these proteins and how they are organized into a novel type of membrane microdomain. (nih.gov)
  • SNARE proteins are essential components of the machinery that facilitates membrane fusion in eukaryotic cells. (gla.ac.uk)
  • The Sec1p / Munc18 (SM) family are a conserved group of proteins that regulate membrane fusion through interactions with their cognate syntaxins. (gla.ac.uk)
  • The yeast SM protein Vps45p regulates membrane fusion through the trans-Golgi / late endosomal system, and interacts directly with the syntaxin (Tlg2p) and the v-SNARE (Snc2p) proteins. (gla.ac.uk)
  • Finally, I have developed an in vitro fusion assay to enable us to dissect the functional significance of the various interactions that Vps45p displays with its cognate SNARE proteins. (gla.ac.uk)
  • The autophagophore membrane then elongates and encloses the molecules to be degraded forming an autophagosome, which occurs in two separate conjugation reactions catalyzed by autophagy-related proteins (ATGs). (hindawi.com)
  • Maggie has strong expertise in synchrotron-based techniques such as small angle X-ray scattering (SAXS) and circular dichroism (CD) techniques, which she uses to develop new methods to study self-assembly in biologically relevant systems, and the structures of proteins and DNAs at membrane interface. (edu.au)
  • To overcome SARS-CoV-2 immune evasion, the relatively conserved, potentially immunogenic NSP4, NSP13, NSP14, membrane, and ORF3a viral proteins may serve as more suitable targets for molecular vaccines or therapeutics than the mutation-prone NSP6, spike, ORF8, or nucleocapsid protein. (bvsalud.org)
  • Pyk2 also interacts with GST-fusion proteins corresponding to the second intracellular loop and the distal carboxyl-terminal tail domains of mGluR1a. (uwo.ca)
  • Membrane-enclosed structures called vesicles transport proteins and lipids across the cell. (jove.com)
  • Their formation is driven by the assembly of different classes of coat proteins, namely COPI, COPII, clathrin, or retromer complex. (jove.com)
  • Coat proteins can help sort the cargo and assemble on the donor membrane to initiate vesicle formation. (jove.com)
  • The COPI and COPII coat proteins share similar structural features with Clathrin but differ in cargo sorting and vesicle formation mechanisms. (jove.com)
  • The Rab family of small GTP-binding proteins has long been implicated in the docking and fusion of transport vesicles with their target membranes. (embl.de)
  • Thisimplies that BIN1 rather bundles actin than decorates single filaments.Third, we explored a strategy to purify an aggregation prone BAR protein.Aggregation is a property common in Peripheral Membrane Proteins. (kth.se)
  • While many studies have been focused on the membrane structure, the dynamics of such systems are crucial for the function of the membrane including membrane bound proteins. (lu.se)
  • Native membrane derived polymer-supported lipid bilayers (nSLBs) are poised to bridge the gap between live cell experiments and traditional model membrane architectures that by offering a combination of accessibility by surface sensitive analytical instrumentation and a composition which more closely resembles cellular membranes by displaying a diversity of endogenous membrane proteins, lipids, and carbohydrates. (lu.se)
  • Due to the lack of detergent solubilization and reconstitution steps, the nSLBs created using this approach contain essentially all of the native lipids, as well as the membrane-associated proteins and carbohydrates from the donor membrane. (lu.se)
  • Genetically mediated defects in epithelial adhesion proteins result in skin and mucous membrane fragility, which predisposes the epithelium to easy bullae formation after minor trauma or sometimes spontaneously. (msdmanuals.com)
  • If the membrane-anchor is missing or defective, Fp and Ip subunits accumulate as soluble proteins in the cytoplasm. (lu.se)
  • Picture shows translocation, pore formation, receptor mediated endocytosis using clathrin coated vesicles and membrane fusion. (rkm.com.au)
  • It mediates fusion of synaptic vesicles with the presynaptic plasma membrane resulting in exocytosis of neurotransmitters. (nature.com)
  • Fusion of synaptic vesicles with the presynaptic membrane occurs in the presence of the NSF (N-ethylmaleimide-sensitive-factor) / α-SNAP (α-soluble NSF attachment protein) disassembly machinery. (nature.com)
  • In vitro membrane-bound vesicles obtained by 'bisecting' (although the two parts were not always identical in size) an in vitro contractile vacuole established their own independent rounding-slackening cycles. (biologists.com)
  • Severed radial arms also became vesiculated and, like contractile vacuole membranes, these in vitro vesicles showed independent rounding-slackening cycles and vesicle-vesicle fusions. (biologists.com)
  • Finally, the enrichment of tetraspanins within secreted vesicles called exosomes, coupled with hints that tetraspanins may regulate vesicle fusion and/or fission, suggests exciting new directions for future research. (nih.gov)
  • Tethered neutrophils enter in membrane-bound vesicles before penetrating into the megakaryocyte cytoplasm. (elifesciences.org)
  • Coated vesicles are transport vesicles that bud off from specialized regions of the cell membrane. (jove.com)
  • COPII vesicles are formed in the ER membranes and mediate transport from ER to the Golgi. (jove.com)
  • We recently developed a generic method for producing polymer-supported lipid bilayers directly from cell-derived native membrane vesicles (NMVs). (lu.se)
  • The entry of enveloped viruses into host cells involves a fusion step between the viral and a cellular membrane. (rupress.org)
  • Binding of gp120 to target cell receptors induces a conformational change in gp41, which then mediates the fusion of viral and cellular membranes. (proteopedia.org)
  • Cell membranes need to change their shapes during many cellular processeslike protein trafficking, cytokinesis and membrane homeostasis. (kth.se)
  • The main function of S2 includes maintaining trimer formation and, upon successive protease cleavages at the S1/S2 junction and a downstream S2' position, mediating membrane fusion to enable cellular entry of the virus. (techstartups.com)
  • The coronavirus spike (S) glycoprotein is a class I viral fusion protein on the outer envelope of the virion that plays a critical role in viral infection by recognizing host cell receptors and mediating fusion of the viral and cellular membranes. (biolegend.com)
  • The trimeric SARS coronavirus (SARS-CoV-2) S glycoprotein consisting of three S1-S2 heterodimers binds the cellular receptor angiotensin-converting enzyme 2 (ACE2) and mediates fusion of the viral and cellular membranes through a pre- to post-fusion conformation transition. (biolegend.com)
  • Cellular electron cryo-tomography revealed a protein layer showing two distinct hexagonal lattices at its membrane-proximal and membrane-distant faces, respectively. (princeton.edu)
  • The LAMP2 gene provides instructions for making a protein called lysosomal associated membrane protein-2 (LAMP-2), which, as its name suggests, is found in the membrane of cellular structures called lysosomes . (medlineplus.gov)
  • The transport of cellular materials into lysosomes requires the formation of cellular structures called autophagic vacuoles (or autophagosomes), which then attach (fuse) to lysosomes. (medlineplus.gov)
  • Recent years have seen strong research efforts on the lipid component of biological membranes. (lu.se)
  • In my talk, I will show you some examples how such biological cues influence the dynamic properties of membranes. (lu.se)
  • Any process that increases the frequency, rate or extent of the formation of a syncytium, a mass of cytoplasm containing several nuclei enclosed within a single plasma membrane, by the fusion of the plasma membranes of two or more individual cells. (planteome.org)
  • Recently, miRNA exocytosis by vesicle fusion in response to stimulation was observed in chromaffin cells, which are neuroendocrine cells in the sympathetic nervous system ( 24 ). (frontiersin.org)
  • To achieve this, the neuronal SNARE (i.e., soluble N -ethylmaleimide-sensitive factor attachment protein receptor) complex brings the vesicle and presynaptic membranes in close proximity, thereby, mediating the fusion of the two membranes resulting in exocytosis of neurotransmitters. (nature.com)
  • New technologies for purifying membrane-bound protein complexes in combination with cryo-electron microscopy (EM) have recently allowed the exploration of such complexes under near-native conditions. (researchgate.net)
  • Group I metabotropic glutamate receptors (mGluRs) are coupled via Galphaq/11 to the activation of phospholipase Cbeta, which hydrolyzes membrane phospholipids to form inositol 1,4,5 trisphosphate and diacylglycerol. (uwo.ca)
  • The SNARE complex assembles from vesicular Synaptobrevin-2 as well as Syntaxin-1 and SNAP25 both anchored to the presynaptic membrane. (nature.com)
  • While the general sequence of SNARE complex formation is well-established, our knowledge on possible intermediates and stable off-pathway complexes is incomplete. (nature.com)
  • Zippering of the SNAREs is proposed to provide the required energy to initiate membrane fusion 6 , 7 and proceeds from the N-terminus towards the membrane-proximal C-terminus through interactions of their complementary SNARE motifs. (nature.com)
  • Based on the presence of glutamine or arginine residues in the zero layer, the SNAREs are classified as Qa- (Syntaxin-1), Qb- and Qc- (SNAP25) or R-SNAREs (Synaptobrevin-2) resulting in the formation of the ternary QabcR (3Q:1R) SNARE complex 8 . (nature.com)
  • While the general sequence of SNARE complex formation is well-established, our knowledge on. (researchgate.net)
  • In this thesis I demonstrate that the Habc domain of Tlg2p has an inhibitory effect on SNARE complex formation. (gla.ac.uk)
  • In a third model, Munc18-1 actively promotes SNARE complex formation and vesicle fusion. (jneurosci.org)
  • During autophagosome maturation, cargo recruitment takes place through the recruitment of ATGs and LC3, and mature autophagosome formation occurs. (hindawi.com)
  • Depolarized mitochondria recruit Parkin to the outer mitochondrial membrane, triggering autophagosome formation, rapid lysosomal fusion, and Parkin redistribution," the team noted. (genengnews.com)
  • 2. NAKED VIRUS - GENOME INJECTION: virus attaches to cell surface and releases its genome which penetrates the cytoplasm via a pore that has been created in the plasma membrane. (rkm.com.au)
  • The phagophore encloses small portions of the cytoplasm to form a double-membrane structure called an autophagosome. (hindawi.com)
  • These findings identify emperipolesis as a new cell-in-cell interaction that enables neutrophils and potentially other cells passing through the megakaryocyte cytoplasm to modulate the production and membrane content of platelets. (elifesciences.org)
  • Penetration occurs almost instantaneously after attachment and is a next step for gaining entry into the cytoplasm by crossing the plasma membrane. (goalfinder.com)
  • While some virus species can directly penetrate the plasma membrane and inject their genetic material into the cytoplasm, the majority of viruses enter cells via endocytosis. (goalfinder.com)
  • To obtain information about BIN1's interaction with themembrane in near native environments, we used artificial lipid systems suchas liposomes and lipids nanotubes.First, we have shown that electrostatic interactions are more important forBIN1 when binding to membranes with low curvature. (kth.se)
  • The formation ofinvaginations (or tubules) is regulated by the composition of negativecharged lipids in membrane bilayer or electrostatic residues on the BARdomain. (kth.se)
  • Pyk2 colocalizes with mGluR1a at the plasma membrane in human embryonic kidney (HEK293) cells and with endogenous mGluR5 in cortical neurons. (uwo.ca)
  • These bend the membrane to form a bud that is released from the donor membrane as a vesicle. (jove.com)
  • The defects (stalks or pores) attract each other via membrane-mediated capillary interactions that result in a condensation transition of the defects. (bgu.ac.il)
  • Using the mutational analysis of recombinant subviral particles of tick-borne encephalitis virus, we provide direct experimental evidence that the initiation of fusion is crucially dependent on the protonation of one of the conserved histidines (His323) at the interface between domains I and III of E, leading to the dissolution of domain interactions and to the exposure of the fusion peptide. (rupress.org)
  • Chemical cross-linking provides detailed insights into these interactions suggesting a role for membrane fusion. (nature.com)
  • The controversy would be solved if binding to closed syntaxin1 were shown to be stimulatory for vesicle fusion and/or additional essential interactions were identified between Munc18-1 and the fusion machinery. (jneurosci.org)
  • The membrane anchor of SQR in mammalian mitochondria and proteobacteria, such as Escherichia coli , consists of two polypeptides (SdhC and SdhD) and contains one heme group. (lu.se)
  • Activity lasted for over 30 min at room temperature (24-27 degrees C). The rounding of the in vitro contractile vacuole corresponded to the increased membrane tension of the in vivo contractile vacuole that occurs immediately before fluid expulsion. (biologists.com)
  • The subsequent slackening of the in vitro contractile vacuole corresponded to the fluid-filling phase of the in vivo contractile vacuole that occurs at decreased membrane tension. (biologists.com)
  • An additional rounding phase of the in vitro contractile vacuole could be induced by applying suction to a portion of its membrane with a micropipette when the contractile vacuole was in its slackened phase. (biologists.com)
  • Furthermore, I have demonstrated that the inhibitory effect of the Habc domain on complex formation can be alleviated by Vps45p in vitro. (gla.ac.uk)
  • Munc18-1 is a part of this fusion machinery, but its role is controversial because it is indispensable for fusion but also inhibits the assembly of purified SNAREs in vitro . (jneurosci.org)
  • 5. ENVELOPED VIRUS - MEMBRANE FUSION: virus enters the cell when its outer membrane fuses with the plasma membrane at the cell surface. (rkm.com.au)
  • Cargo is recruited, enveloped at the inner nuclear membrane (INM), and delivered by membrane fusion at the outer nuclear membrane. (princeton.edu)
  • A buried isoleucine (Ile573) in a central trimeric coiled coil within the fusion-active gp41 ectodomain core is thought to favor this conformational activation. (proteopedia.org)
  • Membrane fusion is critical for many biological processes, especially in eukaryotic development and viral entry. (wikipedia.org)
  • Eukaryotic genomes contain several gene families, of host and viral origin, which encode products involved in driving membrane fusion. (wikipedia.org)
  • Recent evidence, however, suggests that some Rabs may play an additional role in transport vesicle formation. (embl.de)
  • While adult somatic cells do not typically undergo membrane fusion under normal conditions, gametes and embryonic cells follow developmental pathways to non-spontaneously drive membrane fusion, such as in placental formation, syncytiotrophoblast formation, and neurodevelopment. (wikipedia.org)
  • This suggests that maximum tension development in the contractile vacuole membrane can be triggered when tension is increased in any part of the contractile vacuole membrane. (biologists.com)
  • Mounting evidence suggests that the genetic disorders/mutation and diseases change not only the protein expression patterns but also membranes themselves. (lu.se)
  • Another design strategy was developed using gammaretroviruses backbone where 2 domains were substituted with HIV epitopes in the N-terminal part of the ectodomain and the membrane proximal external region (MPER) respectively. (europa.eu)
  • They are found in reoviruses, which are non-enveloped viruses and are specialized for cell-cell rather than virus-cell fusion, forming syncytia. (wikipedia.org)
  • It has been hypothesized that conserved histidines in the class II fusion protein E of these viruses function as molecular switches and, by their protonation, control the fusion process. (rupress.org)
  • NAKED VIRUSES have an exposed protein capsid, whilst ENVELOPED VIRUSES are cloaked in cell membrane, added during budding from the host cell. (rkm.com.au)
  • Direct penetration is observed only in non-enveloped viruses, membrane fusion is observed only in enveloped viruses. (goalfinder.com)
  • The flavin together with the iron-sulfur clusters function to mediate electron transfer from the dicarboxylate binding site on the Fp subunit to the membrane-anchor domain where quinone is reduced to quinol. (lu.se)
  • Flavinylation of Fp in B. subtilis does not require the Ip subunit or the membrane anchor but depends on folding of the Fp polypeptide into a state that can bind FAD and subsequent mediate covalent binding of the FAD [3, 4]. (lu.se)
  • The contractile vacuole of the freshwater protozoan Paramecium multimicronucleatum is a membrane-bound exocytotic vesicle that expels excess cytosolic water. (biologists.com)
  • The binding domain is rich in α-helices and hydrophobic fusion peptides located near the N-terminus. (wikipedia.org)
  • First, phagophore formation requires cytoplasmic vesicle nucleation, which occurs when the ATG1/ULK1 complex, which is comprised of ULK1, FIP200, ATG13, and ATG101, interacts with the Class III PI3K complex. (hindawi.com)
  • This phenomenon occurs in otherwise unmanipulated murine marrow in vivo, resulting in circulating platelets that bear membrane from non-megakaryocytic hematopoietic donors. (elifesciences.org)
  • Some studies have shown that in cells without the LAMP-2 protein, fusion between autophagic vacuoles and lysosomes occurs more slowly, which may lead to the accumulation of autophagic vacuoles. (medlineplus.gov)
  • Generation of a nerve impulse (action potential) of a sensory neurone occurs as a result of a stimulus such as light, a particular chemical, or stretching of a cell membrane by sound. (medscape.com)
  • The primary effect of RA is in joint deformity and fusion, which occurs in the advanced stages. (medscape.com)
  • Fusion conformation change can often be controlled by pH. (wikipedia.org)
  • The overall objective of EuroNeut-41 was to design a vaccine that raises antibodies able to prevent HIV cell fusion by blocking the virus fusion protein gp41 in its pre-fusogenic conformation. (europa.eu)
  • Instead, we consider a scenario for defect-induced membrane fusion that proceeds cooperatively via multiple stalk formation. (bgu.ac.il)
  • Together with Syntaxin-1A and SNAP25, it forms the core membrane fusion machinery that is responsible for neurotransmitter release and, therefore, signal transmission between neurons. (researchgate.net)
  • Here, we report on the clinical impact of a novel NiV-derived nonspreading replicon particle lacking the fusion (F) protein gene (NiVF) as a vaccine in three small animal models of disease. (cdc.gov)
  • Fifty-one vaccine candidates were designed mainly to mimic fusion intermediate conformations of gp41 and in some instance to increase exposure of the 2F5/4E10 epitopes. (europa.eu)
  • Our results demonstrate that the proper folding of the gp41 core underlies the membrane fusion properties of the gp120-gp41 complex. (proteopedia.org)
  • Structural and functional analysis of the HIV gp41 core containing an Ile573 to Thr substitution: implications for membrane fusion. (proteopedia.org)
  • Liu J, Shu W, Fagan MB, Nunberg JH, Lu M. Structural and functional analysis of the HIV gp41 core containing an Ile573 to Thr substitution: implications for membrane fusion. (proteopedia.org)
  • Predicted to be integral component of mitochondrial membrane. (nih.gov)
  • Integral membrane protein. (lu.se)
  • The peptide regions required to drive fusion are formed from the turns between the β-sheets. (wikipedia.org)
  • Lukatsky, DB & Frenkel, D 2004, ' Multiple stalk formation as a pathway of defect-induced membrane fusion ', European Physical Journal E , vol. 14, no. 1, pp. 3-6. (bgu.ac.il)
  • Canonical autophagy initiates with the formation of a small vesicular sac called a phagophore (Figure 1 ). (hindawi.com)
  • A new hydrogen-bonding interaction between the buried Thr573 and Thr569 residues appears to allow formation of the trimer-of-hairpins structure at physiological temperature. (proteopedia.org)
  • Syncytin-1 Syncytin-2 ERV3 is not functional in humans HAP2 is a domesticated viral class II fusion protein found in diverse eukaryotes including Toxoplasma, vascular plants, and fruit flies. (wikipedia.org)
  • Ring formation by Vibrio fusion protein composed of FliF and FliG, MS-ring and C-ring component of bacterial flagellar motor in membrane' by Kanji Takahashi, Tatsuro Nishikino, Hiroki Kajino, Seiji Kojima, Takayuki Uchihashi, Michio Homma is published in BPPB as the J-STAGE Advance Publication. (biophys.jp)
  • In the Fp subunit of SQR, and the closely related membrane-associated fumarate reductase of anaerobic organisms, FAD is covalently attached via an 8α-N(3)-histidyl linkage to a histidine (His) in a conserved sequence in the N-terminal part of the polypeptide. (lu.se)
  • Treatment with NMT inhibitor IMP-1088 potently abrogated VACV infection, while VACV gene expression, DNA replication, morphogenesis and EV formation remained unaffected. (cdc.gov)
  • HN - 2008 BX - Lateral Sinus MH - Atrial Septum UI - D054087 MN - A07.541.459.249 MS - The thin membrane-like muscular structure separating the right and the left upper chambers (HEART ATRIA) of a heart. (bvsalud.org)
  • Notably, certain B. subtilis mutants with mutated Fp lack covalently bound flavin and do not assemble the SQR polypeptides in the membrane [3]. (lu.se)
  • Spindle pole bodies (SPBs) provide a structural basis for genome inheritance and spore formation during meiosis in yeast. (rupress.org)
  • and consequently membrane deformation.Second, we clarified BIN1's role in actin dynamics. (kth.se)
  • With this Dynamics workshop, our goal is to bring together leading experts in the field of membrane dynamics, with a particular focus on neutrons and X-rays, but also complementary techniques including NMR, single molecule spectroscopy and computer modeling. (lu.se)
  • Epithelial fragility and easy blistering of skin and mucous membranes usually manifest at birth or in infancy. (msdmanuals.com)
  • Here, we employed transmission electronmicroscopy and other biophysical methods to elucidate how BAR domainproteins steer processes at the membrane.In this work we studied the BAR protein bridging integrator 1 (BIN1), whichhas an established role in cancer, Alzheimer's disease and skeletalmyopathies. (kth.se)
  • As cell membranes are both dynamic and compositionally complex, replicating these aspects in a model membrane are essential. (lu.se)