Wyniki wyszukiwania

1

Structural biology of the influenza virus fusion peptide

100%

Worch R.

Acta Biochimica Polonica

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2014

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tom 61

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nr 3

2

The role of target membrane sialic acid residues in the fusion activity of the influenza virus: the effect of two types of ganglioside on the kinetics of membrane merging

100%

Ramalho-Santos J., Pedroso De Lima M. C.

Cellular and Molecular Biology Letters

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2004

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tom 09

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nr 2

The influenza virus enters target cells via the action of hemagglutinin proteins (HA) inserted into the viral envelope. HA promotes membrane fusion between the viral envelope and endosomal membrane at low pH, following viral binding to sialic acid-containing receptors on target cells, and internalization by endocytosis. The effect of target membrane sialic acid residues on the fusion activity of the influenza virus towards model membranes was evaluated by both reduction, (i.e. treating somatic cells with neuraminidase- (NA-) prior to virus-cell interactions), and by supplementing liposomes with the gangliosides GD1a and GT1b. The harshness of the neuraminidase pretreatment of target cells required to affect virus-induced membrane merging was found to greatly depend on the assay conditions, i.e. whether a virus-cell prebinding step at neutral pH was included prior to acidification. Minor concentrations of neuraminidase were found to greatly reduce virus fusion, but only in the absence of a prebinding step; they had no effect if this step was included. Although membrane merging was greatly reduced following cell neuraminidase pretreatment, virus-cell association at low pH was not disturbed proportionately. This probably reflects unspecific virus-cell binding under these conditions, probably of inactivated or aggregated virus particles, which does not translate into membrane merging. This seems to suggest both that target membrane sialic acid can protect the virus from losing its activity before triggering membrane merging, and that the importance of this interaction is not merely to ensure virus-target proximity. With liposomes, we found that both types of ganglioside supported efficient fusion, with GD1a promoting a slightly faster initial rate. However, in this case, virus-target proximity closely mirrored fusion activity, thus pointing to differential specificity between targets routinely used to assay influenza virus fusion activity.

3

Involvement of interfacial instability in morphological changes of some membrane-bound bodies

86%

Coakley W. T.

Cellular and Molecular Biology Letters

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1996

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tom 01

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nr 3

Systems consisting of single membranes or of interacting membranes with an intervening aqueous layer can be modelled as interfacial regions. Treatments of the stability of thin fluid films against bending and squeezing waves give guidance on the behaviour of such regions. Evidence of bending wave instability on erythrocyte membranes when the spectrin component of the membrane skeleton is denatured is presented. There are two alternative outcomes of such instability. In one case a regular surface wave grows on the rim of the erythrocyte at rates of the order of 3 s-1 and vesicles pinch from the wave crests. In the second outcome the cell rounds up and the membrane partially internalises a discoid volume of suspending phase. The rim of that volume becomes unstable and sends vesicles into the cell. The outcome (internalisation or externalisation of membrane) can be controlled experimentally by altering the surface charge or the transmembrane potential or by exposure to amphiphilic drugs. When two interacting membranes of normal erythrocytes at room temperature adhere in the presence of adhesion-inducing polymers or of lectins two distinct adhesion outcomes are also possible. In one case parallel membranes form a continuous seam. In the second outcome localised regions of close contact formed at regular intervals along the membrane surface are separated by regions of larger normal separation. The characteristic lateral spacing of contact regions changes with different modifiers of the membrane interaction profile in a manner consistent with interfacial instability theory.

4

On the mechanism of protein-induced membrane fusion: from model to biological membranes

86%

Hoekstra D., Martin I., Kahya N., Ruysschaert J. M., Pecheur E.

Cellular and Molecular Biology Letters

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2002

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tom 07

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nr 2

5

Properties of layered membranes as the basis for membrane fusion and vesiculation processes

86%

Svetina S., Iglic A., Zeks B.

Biophysics of Membrane Transport

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1994

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tom 12

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nr 2

6

Polyunsaturated lipids in membrane fusion events

86%

Teague W. E., Fuller N. L., Rand R. P., Gawrisch K.

Cellular and Molecular Biology Letters

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2002

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tom 07

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nr 2

7

Effects of amphiphiles on cell membranes and membrane-connected events

58%

Isomaa B., Hagerstrand H., Makela J. H.

Biophysics of Membrane Transport

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1992

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tom 11

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nr 1

8

Annexins and ATP in membrane traffic: a comparison with membrane fusion machinery

58%

Bandorowicz-Pikula J., Pikula S.

Acta Biochimica Polonica

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1998

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tom 45

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nr 3

Annexins, calcium- and membrane-binding multifunctional proteins, have been implicated in N-ethylmaleimide (NEM)-independent fusion of vesicular structures involved in membrane traffic. This view is based on intracellular localization of annexins, which frequently associated with endosomes, chromaffin granules, caveolae, clathrin-coated pits, and other membrane compartments, engaged in endo- and exocytosis. Moreover, annexins were found to modulate budding and aggregation of vesicle membranes, to interact with cytoskeletal proteins, and, upon binding to membranes, to change the structure of lipid bilayer, leading to membrane fusion. In addition, some annexins are substrates for various protein kinases and, in membrane-bound form, reveal calcium channel activity. Recently, annexins were observed to interact in vitro and in vivo with nucleotides, ATP, GTP or cAMP, which are potent mediators of membrane traffic processes. In addition, annexin VII showed hydrolytic activity towards GTP, and similarities in the mechanism of action to that of small GTP-binding proteins were found. The aim of the present review is to summarize the observations implying annexins as possible effectors in endo- and exocytosis and to compare them with well known complexes of cytosolic and membrane proteins forming the true membrane fusion machinery within a cell, conserved from yeast to the neurons of humans.

Ograniczanie wyników

Structural biology of the influenza virus fusion peptide

The role of target membrane sialic acid residues in the fusion activity of the influenza virus: the effect of two types of ganglioside on the kinetics of membrane merging

Involvement of interfacial instability in morphological changes of some membrane-bound bodies

On the mechanism of protein-induced membrane fusion: from model to biological membranes

Properties of layered membranes as the basis for membrane fusion and vesiculation processes

Polyunsaturated lipids in membrane fusion events

Effects of amphiphiles on cell membranes and membrane-connected events

Annexins and ATP in membrane traffic: a comparison with membrane fusion machinery