Stalk membrane fusion. Medical search. Frequent questions

Fusion is also an important mechanism for transport of lipids from their site of synthesis to the membrane where they are needed. (wikipedia.org)
These studies have shown that divalent cations play a critical role in the fusion process by binding to negatively charged lipids such as phosphatidylserine, phosphatidylglycerol and cardiolipin. (wikipedia.org)
Whatever the mechanism of calcium-induced fusion, the initial interaction is clearly electrostatic, since zwitterionic lipids are not susceptible to this effect. (wikipedia.org)
Lipids are an integral part of cells, being the principal component of the cell membrane, and contributing to the function and regulation of biological processes. (umass.edu)
To that end, this thesis explores the creation of large area biomembranes along with the development of electromechanical and optical characterization methods with the goal of determining structure-function relationships of membranes and their constituent lipids in different compositional and ionic environments. (umass.edu)
The lipids of the lipoplex fuse with the endosome's membrane. (sciencedaily.com)
The lipids form a stalk-like connection and when both layers are fused, a pore opens up that connects the water channels to the cell's interior, allowing the DNA to escape,' says Bruininks. (sciencedaily.com)
Membrane phase behavior in cells permits transient concentration of specific proteins and lipids into dynamic nanoscopic domains. (gutoch.info)
We observe both sources of contrast in biomimetic membranes composed of saturated lipids, unsaturated lipids, and cholesterol. (gutoch.info)
Organelles are also identified by the presence of specific Phosphoinositide (PI) lipids on the cytosolic leaflet of their membrane. (upstate.edu)

Even the entry of pathogens can be governed by fusion, as many bilayer-coated viruses have dedicated fusion proteins to gain entry into the host cell. (wikipedia.org)
The fusion of neurotransmitter filled vesicles with the presynaptic membrane is the key step in the neuronal signaling cascade and is mediated by soluble N-ethylmaleimide-sensitive factor attachment receptor proteins (SNAREs). (uni-goettingen.de)
The interaction of the three SNARE proteins synaptobrevin 2 (syb 2), syntaxin 1A, and SNAP25 (synaptosomal associated protein of 25 kDa) is pivotal to overcome the energy barrier that leads to merging of the opposing lipid bilayers and results in the transfer of neurotransmitters across the presynaptic membrane and into the synaptic cleft. (uni-goettingen.de)
The SARS-CoV-2 genome contains a single 29,903 bp RNA strand that codes for replicase-transcriptase, and spike, envelope, membrane, and nucleocapsid structural proteins. (cd-genomics.com)
Measles virus (MV) an enveloped RNA pathogen owned by the family members enters the cell through membrane fusion mediated by two viral envelope protein an attachment proteins hemagglutinin (H) and a fusion (F) proteins. (conferencedequebec.org)
rearrangements from the stalk area which cause conformational adjustments from the F proteins. (conferencedequebec.org)
Dynamin-related proteins (DRPs) are large multidomain GTPases required for diverse membrane-remodeling events. (ox.ac.uk)
The plasma membrane is not only the first point of encounter for many types of environmental stress, but given the diversity of receptor proteins and their associated molecules also represents the site at which many cellular signal cascades originate. (cell-stress.com)
The plasma membrane can be envisioned as a central compartment in the cellular adaptation to diverse stress conditions as it shapes the interactions between cells and their environment by harboring an elaborate complement of transmembrane proteins, e.g. transporters, channels, receptors, or adhesion proteins. (cell-stress.com)
For example, alkaline vacuole/lysosome are deficient in autophagy, Golgi pH regulates its ability to glycosylate proteins and failure to maintain endosomal pH perturbs with its ability to recycle receptors to the Plasma membrane or, the trans-Golgi. (upstate.edu)

Here, we tested the existence and role of such phase behavior in endoplasmic reticulum (ER) membranes. (gutoch.info)
Homotypic membrane fusion of the endoplasmic reticulum is mediated by dynamin-like guanosine triphosphatases (GTPases), which include atlastin (ATL) in metazoans and Sey1p in yeast. (diamond.ac.uk)

Using the expression for the elastic energy of the stalk it was possible to find the value of the spontaneous curvature of its membrane, Ks, at which the existence of a stalk is in principle possible. (tau.ac.il)
The Er Membrane Is Typically Thinner And More Fluid Than The Plasma Membrane And It Contains More Curvature. (gutoch.info)
Here we will focus on vesicle (membrane) fusion and how its kinetics depends on the surfactant monolayer spontaneous curvature, H0. (lu.se)
We find that the stalk formation energy decreases with curvature by up to 31 k B T in a 20-nm-radius vesicle compared with planar membranes and by up to 8 k B T in the fusion of highly curved, long, tubular membranes. (haifa.ac.il)
In contrast, in the fusion of long tubular compartments, the surface tension does not accumulate due to the formation of the diaphragm, and the energy barrier for pore expansion increases with curvature by up to 11 k B T. This suggests that inhibition of polymorphic virus infection could particularly target this feature of the second barrier. (haifa.ac.il)

Many broadly neutralizing antibodies (bnAbs) bind to conserved areas of the hemagglutinin (HA) stalk region and can inhibit the low pH induced HA conformational changes necessary for viral membrane fusion activity. (cdc.gov)
Analysis of this HA gene shows that it is closely related to avian A(H5) viruses in HA clade 2.3.4.4b and lacked amino acid changes that improve recognition of mammalian receptors or fusion of the viral membrane with the host endosomal membranes. (cdc.gov)
A(H5) viruses in HA clade 2.3.4.4b and lacked amino acid changes that improve recognition of mammalian receptors or fusion of the viral membrane with the host endosomal membranes. (cdc.gov)

Two principal fusion mechanisms are identified: the stalk mechanism, starting with the appearance of a stalk between approaching membranes, and the adhesion mechanism which involves bilayer reorganization as a result of a tight junction of the membranes. (tau.ac.il)
The origin and evolution of the monolayer and bilayer stalks between membranes are analysed. (tau.ac.il)
Alternatively, if only one leaflet from each bilayer is involved in the fusion process, the bilayers are said to be hemifused. (wikipedia.org)
Fusion is involved in many cellular processes, particularly in eukaryotes since the eukaryotic cell is extensively sub-divided by lipid bilayer membranes. (wikipedia.org)
One role on these ions in the fusion process is to shield the negative charge on the surface of the bilayer, diminishing electrostatic repulsion and allowing the membranes to approach each other. (wikipedia.org)
The presence of the uncharged headgroup phosphatidylethanolamine (PE) increases fusion when incorporated into a phosphatidylcholine bilayer. (wikipedia.org)
Towards this end, we have performed experiments exploring calcium induced vesicle growth, adhesion of vesicles on the bilayer surface, and demonstrated analytical approaches to quantify deposition, growth, and fusion. (umass.edu)

The spike protein is present as a trimer in mature viruses, with three receptor binding S1 heads lying on top of the S2 stalk of a trimeric membrane fusion. (cd-genomics.com)

In the fusion process, the lipid head group is not only involved in charge density, but can affect dehydration and defect nucleation. (wikipedia.org)
To rationalize these findings by the distinct lipid compositions, we computed ~200 free energies of stalk formation in membranes with different lipid head groups, tail lengths, tail unsaturations, and sterol content. (gutoch.info)

Under the current model, the protein has at least three conformational states: pre-fusion native state, pre-hairpin intermediate state, and post-fusion hairpin state. (cusabio.com)
claim that the dimer-dimer relationships from the MV-H mind domain specifically that in type I donate to triggering membrane fusion which conformational change of mind domain tetramers is important in the procedure. (conferencedequebec.org)
We present crystal structures of a Vps1 GTPase-bundle signaling element (BSE) fusion in different nucleotide states to capture GTP hydrolysis intermediates and concomitant conformational changes. (ox.ac.uk)

We explored the Young's modulus and bending rigidity of DOPC, DOPG symmetric and asymmetric membranes using electrostriction. (umass.edu)
Many biological membranes are asymmetric and exhibit complex lipid composition, comprising hundreds of distinct chemical species. (gutoch.info)

If, in addition, fusion events are rare, a vesicle dispersion may retain its size distribution for weeks and months. (lu.se)
Vesicle fusion was also studied with giant uni-lamellar vesicles using rapid confocal laser scanning microscopy. (lu.se)

These energy barriers determine the speed and success rate of many critical biological processes, including the fusion of highly curved membranes, for example synaptic vesicles and enveloped viruses. (haifa.ac.il)

mediates fusion of the virion and cellular membranes by acting as a class I viral fusion protein. (cusabio.com)
Membrane-associated Hsp72 from tumor-derived exosomes mediates STAT3-dependent immunosuppressive function of mouse and human myeloid-derived suppressor cells. (scienceopen.com)

However, these stresses relax over time due to lipid flip-flop from the proximal monolayer, resulting in a larger hemifusion diaphragm and a higher fusion pore formation energy barrier, up to 35 kBT. (haifa.ac.il)

Fusion of cellular membranes begins with the formation of a stalk. (gutoch.info)
Since these signaling pathways affect virtually all aspects of cellular life, changes in the plasma membrane proteome appear ideally suited to contribute to the cellular adaptation to stress. (cell-stress.com)

The models of the active mitoribosome explain how mRNA binds through a dedicated protein platform on the small subunit, tRNA is translocated with the help of the protein mL108, bridging it with L1 stalk on the large subunit, and nascent polypeptide paths through a newly shaped exit tunnel involving a series of structural rearrangements. (nature.com)

abstract = "Based on literary data, conditions necessary for membrane fusion are discussed. (tau.ac.il)

Proteolysis by cathepsin CTSL may unmask the fusion peptide of S2 and activate membranes fusion within endosomes. (cusabio.com)
Initially, coronaviruses connect to a cell surface receptor to enter host cells for viral binding, then enter endosomes, and eventually combine the viral and lysosomal membranes. (cd-genomics.com)

When extended to isolated mammalian plasma membranes, these methods reveal similar nanoscale lateral heterogeneities. (gutoch.info)

Simultaneous imaging of lipid dye diffusion from the PSM into the vesicular membrane via a fusion stalk was used to quantify different fusion pathways. (uni-goettingen.de)

The method reveals that the inner leaflet of a typical plasma membrane is far more fusogenic than the outer leaflet, which is likely an adaptation to evolutionary pressure. (gutoch.info)

The hemagglutinin (HA) gene codes for one of the two surface glycoproteins and is central to species specificity because it is responsible for virus attachment and fusion with host cells. (cdc.gov)

It is proposed that fusion mechanisms should be classified according to the primary act involving a change in the membrane structure. (tau.ac.il)
Our laboratory is interested in the molecular mechanisms and physiological roles of mitochondrial fusion. (jhmi.edu)

If this fusion proceeds completely through both leaflets of both bilayers, an aqueous bridge is formed and the internal contents of the two structures can mix. (wikipedia.org)
PSMs are continuous lipid bilayers with solid supported parts (s-PSM) as well as freestanding membranes spanning large aqueous compartments (f-PSM). (uni-goettingen.de)

Cationic lipid within the membrane promotes adhesion and retention of vesicles. (umass.edu)

The lipoplex can fuse with the endosome membrane, allowing the DNA to enter the cell. (sciencedaily.com)
In addition, the SARS-CoV spike at the S1/S2 boundary must be proteolytically accessed to fuse membranes, such that S1 dissociates and S2 undergoes significant systemic reform. (cd-genomics.com)

Instead, we consider a scenario for defect-induced membrane fusion that proceeds cooperatively via multiple stalk formation. (bgu.ac.il)

As a result, the ER membrane is thinner and sparser than plasma membrane, with more unsaturated lipid tails. (gutoch.info)
however, it has recently been identified on the plasma membrane of several cell types including hepatocytes where it functions as the HDL receptor, on endothelial cells where it may act as the angiostatin receptor, and on the surface of cancer cells. (thermofisher.com)
Some of these stress programs such as the heat shock response are understood in great detail, while other aspects remain largely elusive including potential stress-dependent adaptations of the plasma membrane proteome. (cell-stress.com)

In contrast, the fusion pore formation energy barrier shows a more complicated behavior. (haifa.ac.il)

V-ATPase is made of two subcomplexes: a cytosolic V 1 that carries out ATP hydrolysis, and a membrane bound V o that is responsible for proton translocation. (upstate.edu)

According to the stalk hypothesis of fusion, a highly curved bridge must form between the two bilayers for fusion to occur. (wikipedia.org)
Immediately after stalk expansion to the hemifusion diaphragm, the fusion pore formation energy barrier is low (15-25 k B T) due to lipid stretching in the distal monolayers and increased tension in highly curved vesicles. (haifa.ac.il)

This is clearly not the only role, however, since there is an extensively documented difference in the ability of Mg2+ versus Ca2+ to induce fusion. (wikipedia.org)
Although Mg2+ will induce extensive aggregation it will not induce fusion, while Ca2+ induces both. (wikipedia.org)
An alternate explanation is that the physical rather than chemical nature of PE may help induce fusion. (wikipedia.org)
HEK293T cells were transfected with an empty vector ((31) exhibited using transcomplementation experiments that receptor binding to only one dimer of the MV-H head domain name dimer of dimers can induce F protein triggering mediated by the stalks of the other dimer. (conferencedequebec.org)

The resulting dense phase of stalks corresponds to the so-called fusion intermediate. (bgu.ac.il)
0 is consistent with membrane fusion models involving the so-called stalk intermediate structure. (lu.se)

The energy barrier of the hydrophobic interaction and the elastic energy barrier, which have to be overcome by the membranes to form the stalk are analysed. (tau.ac.il)
Here we use continuum elastic theory of lipid monolayers to determine the relationship between membrane shape and energy barriers to fusion. (haifa.ac.il)

The delivery process faces a multitude of challenges, so a rational design approach for vesicles that considers a lipid's physicochemical contribution to the membrane is desired. (umass.edu)
Thus they are suitable to monitor the process of content transfer through a fusion pore of added vesicles filled with a water soluble dye by means of fluorescence microscopy. (uni-goettingen.de)

It has been shown by freeze-fracture electron microscopy that the addition of Ca+2, Mg+2, Mn+2 or Cd+2 to suspensions of egg phosphatidylcholine and cardiolipin (1:1 or 3:1) leads to the formation of numerous intramembrane particles (imp's) and crater-like (stalk) structures. (tau.ac.il)
SIGNIFICANCE We have used cryoEM to achieve direct, probe-free imaging of lateral domains in biomimetic lipid membranes under native conditions and to characterize differences in their structures. (gutoch.info)

During viral and target cell membrane fusion, the coiled coil regions (heptad repeats) assume a trimer-of-hairpins structure, positioning the fusion peptide in close proximity to the C-terminal region of the ectodomain. (cusabio.com)

Using a coarse grain molecular dynamics simulation, the fusion process between the lipoplex and the endosome membrane was visualized, as well as the subsequent escape of the DNA. (sciencedaily.com)
The membranes inhibitory for the NTs download manual of structural kinesiology 2011 of sufficient synapsis and homodimeric excitability corepressor of protein by ciliary early transporters and tails are found in this domain as six unintegrated dynamics: protein 1. (erik-mill.de)

The results suggest that receptor binding and F protein triggering could be communicated across two MV-H dimers either at the head domain or at the stalk region. (conferencedequebec.org)
Confocal micrograph of a transgenic zebrafish embryo at 24 hours post-fertilization, showing expression of the fusion protein PARD3_GFP. (cellimagelibrary.org)
Projection of a HeLa cell expressing a YFP-SC35 fusion protein that localizes to nuclear speckles and in a diffuse nuclear localization. (cellimagelibrary.org)

Furthermore, the NA has a full-length stalk which is consistent with viruses that naturally circulate in wild birds. (cdc.gov)

We propose that the first stage of membrane fusion need not be the formation of a single stalk. (bgu.ac.il)
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)
It is shown that, within the framework of the stalk mechanism, there exists a possibility of either the formation of a stalk of a finite radius, or complete fusion. (tau.ac.il)
The theoretical analysis of the stalk formation mechanism is supported by experimental data. (tau.ac.il)
Since PE has a small headgroup and readily forms inverted micelle phases it should, according to the stalk model, promote the formation of these stalks. (wikipedia.org)
This enables us to map the lipid-dependent physical property changes for bilayers, relate lipid composition to physical rearrangement such as formation of a fusion stalk, and compare them to existing literature for other platforms. (umass.edu)
Here, we study how membrane complexity controls the energetics of the first steps of membrane fusions, that is, the formation of a stalk. (gutoch.info)
In summary, the simulations reveal a drastic influence of the lipid composition on stalk formation and a comprehensive fusogenicity map of many biologically relevant lipid classes. (gutoch.info)
Here, the authors develop a computationally efficient method for coarse-grained simulations of stalk formation and apply this approach to comprehensively analyse how stalk formation is influenced by the membrane lipid composition. (gutoch.info)
The formation of this structure appears to drive apposition and subsequent fusion of viral and target cell membranes. (cusabio.com)
The fusion of lipid membranes progresses through a series of hemifusion intermediates with two significant energy barriers related to the formation of stalk and fusion pore, respectively. (haifa.ac.il)
Furthermore our outcomes indicate that even though the stalk and transmembrane regions may be mainly responsible for the tetramer formation of MV-H the head domain alone can form tetramers albeit at a low efficiency. (conferencedequebec.org)
This substitution may facilitate steady formation of type II by detatching sugars between SLAM and MV-H in type II thus facilitating fusion triggering. (conferencedequebec.org)

In membrane biology, fusion is the process by which two initially distinct lipid bilayers merge their hydrophobic cores, resulting in one interconnected structure. (wikipedia.org)
Identifying the biological function and advantage of this complexity is a central goal of membrane biology. (gutoch.info)

The nature of this organization has remained elusive due to a lack of methods to directly probe nanoscopic membrane features. (gutoch.info)

Toldt in the duct of the odd type in the cloacal membrane, which reveal the patient. (goldenowlhunt.com)

That is why scientists are now experimenting with lipid-based complexes, which are similar to cell membranes. (sciencedaily.com)
attaches the virion to the cell membrane by interacting with host receptor, initiating the infection. (cusabio.com)
Cell damage was assessed using MTT assays, and the lactate dehydrogenase (LDH) release rate and flow cytometry were used to detect the accumulation of reactive oxygen species (ROS) and mitochondrial membrane potential respectively. (sdbonline.org)
Most prominent in this image are the cell bodies and proximal dendrites (including the stalk o. (cellimagelibrary.org)
The goals of our research are to understand the molecular basis of mitochondria fusion using biochemical approaches and to determine the physiological roles of mitochondrial fusion using cell culture and animal models. (jhmi.edu)

The remainder subunits are components of two stalk domains and the proton pumping F0 part of the machinery. (thermofisher.com)

GSOs also mitigated the deleterious effects of GLU on the mitochondrial membrane potential and Cyt C release, thus alleviating mitochondrial dysfunction, and increased GSH levels and CAT activity in both cells and Drosophila brain tissue. (sdbonline.org)
The regulation of membrane fusion and fission generates a striking diversity of mitochondrial shapes, ranging from numerous small spheres in hepatocytes to long branched tubules in myotubes. (jhmi.edu)
In addition to shape and number, mitochondrial fusion is critical for normal organelle function. (jhmi.edu)
For example, mice that are defective in mitochondrial fusion die during early development while yeast fusion mutants rapidly lose their mitochondria genome and become incapable of oxidative phosphorylation. (jhmi.edu)
Moreover, mitochondrial fusion also regulates the release of cytochrome C during apoptosis. (jhmi.edu)
Therefore, it is not surprising that defects in mitochondrial fusion cause neurodegenerative disorders in humans, including Charcot-Marie-Tooth disease type 2A and autosomal dominant optic atrophy. (jhmi.edu)
Using yeast as a model system, we have identified several components that mediate and regulate mitochondrial fusion. (jhmi.edu)
Murata D, Yamada T, Tokuyama T, Arai K, Quirós PM, López-Otín C, Iijima M, Sesaki H. Mitochondrial Safeguard: a stress response that offsets extreme fusion and protects respiratory function via flickering-induced Oma1 activation. (jhmi.edu)

The nanoscale organization of biological membranes into structurally and compositionally distinct lateral domains is believed to be central to membrane function. (gutoch.info)

We show here that cryogenic electron microscopy (cryoEM) can be used to directly image coexisting nanoscopic domains in synthetic and bio-derived membranes without extrinsic probes. (gutoch.info)
This reaction is accomplished by a flux of protons across the membrane as a result of electron transfer. (thermofisher.com)

Exocytosis, fertilization of an egg by sperm and transport of waste products to the lysosome are a few of the many eukaryotic processes that rely on some form of fusion. (wikipedia.org)
The amoebae which form the head and the spores, climb up the stalk. (biologydiscussion.com)

Die Fusion von Neurotransmitter gefüllten Vesikeln mit der präsynaptischen Membran ist der Schlüsselschritt in der neuronalen Signaltransduktion und wird durch SNARE- (soluble N-ethylmaleimide-sensitive factor attachment receptor) Proteine vermittelt. (uni-goettingen.de)
the F1 ATP-ase (soluble) and the F0 ATP-ase (membrane embedded). (thermofisher.com)
Journal cover: V-ATPase is regulated by disassembly into soluble V 1 (shown in cyan) and membrane integral V o (shown in gold) subcomplexes. (upstate.edu)

Simulations of phase separated bilayers were used to predict two sources of contrast between coexisting ordered and disordered phases within a single liposome, namely differences in membrane thickness and molecular density. (gutoch.info)

The stalk mechanism. (tau.ac.il)

Our present outcomes with MV-H mutants as well as these prior observations by us yet others highly indicate the fact that dimer-dimer connections of MV-H mind domain play an important function in triggering membrane fusion. (conferencedequebec.org)

To investigate this fundamental process, pore-spanning membranes (PSMs) were utilized in this work as a model system of the presynaptic membrane. (uni-goettingen.de)

This topic also remains controversial, and even if there is a curved structure present in the fusion process, there is debate in the literature over whether it is a cubic, hexagonal or more exotic extended phase. (wikipedia.org)

There are four fundamental steps in the fusion process, although each of these steps actually represents a complex sequence of events. (wikipedia.org)

Depending on whether hemifusion or full fusion occurs, the internal contents of the membranes may mix at this point as well. (wikipedia.org)

In previous A(H5N1) outbreaks and zoonosis the NA stalk region often had deletions (e.g., a 20 amino acid deletion at positions 49-68 relative to A/goose/Guangdong/1/1996) that enhances replication and/or pathogenesis in terrestrial poultry and mice ( 4-6 ). (cdc.gov)
Other Interesting Places to Visit near Aix-en-Provence Aix-en-Provence is at the heart of Provence, a region brimming with fascinating historic towns and quaint medieval villages. (businessopad.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)

The stalk domain of S contains three hinges, giving the head unexpected orientational freedom. (cusabio.com)
The heap of amoebae is gradually differentiated into a stalked sorocarp having a head containing spores. (biologydiscussion.com)

A novel interface between adjacent GTPase domains forms in Vps1 instead of the contacts between the BSE and adjacent stalks and GTPase domains as seen in dynamin. (ox.ac.uk)

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